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Sample records for axisymmetric tandem mirror

  1. Axisymmetric tandem mirror stabilized by a magnetic limiter

    International Nuclear Information System (INIS)

    Kesner, J.; Post, R.S.; Lane, B.

    1985-06-01

    In order to stabilize MHD-like, fast growing m = 1 fluctuations in the central cell of a tandem mirror we propose the introduction of a magnetic limiter. The magnetic limiter would create a ring null in the magnetic field. Electrons which enter the null can stream azimuthally and thereby ''short-circuit'' m = 1 fluctuations. Some pressure could be maintained on the separatrix flux surface by locating the null on a local magnetic maxima or by axial plugging. This scheme introduces the possibility of a fully axisymmetric tandem mirror

  2. Potential formation in axisymmetrized tandem mirror GAMMA 10

    International Nuclear Information System (INIS)

    Cho, T.; Ichimura, M.; Inutake, M.

    1985-01-01

    The paper reports experimental results on potential formation and end plugging in the axisymmetrized tandem mirror GAMMA 10. The plugging at both ends has been achieved by a combination of neutral beams and gyrotrons. The presence of a plug potential with a thermal barrier in an axisymmetric mirror has been confirmed by direct measurement of the axial potential profile. Enhancement of axial particle confinement has been observed during the end plugging. Non-ambipolar radial transport has been greatly reduced in the axisymmetrized magnetic configuration. The potentials measured by beam probes and end loss analysers are 0.7, 0.4 and 1.1 kV in the central, barrier and plug regions, respectively. Strong end plugging is observed when the central-cell density is higher than the densities in the plug and the barrier, and the plug density remains higher than the barrier density. The plug electron temperature is higher than the central temperature. Hot electrons forming a football-shaped profile have been stably produced in the axisymmetric mirror. The beta value and the fraction of the hot electrons reach up to 5% and 0.8, respectively. Central-cell ion-cyclotron resonance heating can sustain a stable plasma with higher density and ion temperature when resonance surfaces exist in both the anchor and the central cells. (author)

  3. Preliminary summary of particle transport effects in non-axisymmetric tandem mirrors

    International Nuclear Information System (INIS)

    Baldwin, D.E.

    1978-01-01

    This report reviews the physical basis for the theory of enhanced transport in non-axisymmetric tandem mirror systems recently published by Ryutov, et al. For TMX and thermal ions in a reactor, the radial loss is estimated to be somewhat less than the axial loss; energetic alphas in reactors are susceptible to rapid loss. A number of variations of current magnetic field designs are suggested for reducing this transport

  4. Tandem mirror reactor

    International Nuclear Information System (INIS)

    Moir, R.W.; Barr, W.L.; Carlson, G.A.

    1977-01-01

    A parametric analysis and a preliminary conceptual design for a 1000 MWe Tandem Mirror Reactor (TMR) are described. The concept is sufficiently attractive to encourage further work, both for a pure fusion TMR and a low technology TMR Fusion-Fission Hybrid

  5. Compact neutron imaging system using axisymmetric mirrors

    Science.gov (United States)

    Khaykovich, Boris; Moncton, David E; Gubarev, Mikhail V; Ramsey, Brian D; Engelhaupt, Darell E

    2014-05-27

    A dispersed release of neutrons is generated from a source. A portion of this dispersed neutron release is reflected by surfaces of a plurality of nested, axisymmetric mirrors in at least an inner mirror layer and an outer mirror layer, wherein the neutrons reflected by the inner mirror layer are incident on at least one mirror surface of the inner mirror layer N times, wherein N is an integer, and wherein neutrons reflected by the outer mirror are incident on a plurality of mirror surfaces of the outer layer N+i times, where i is a positive integer, to redirect the neutrons toward a target. The mirrors can be formed by a periodically reversed pulsed-plating process.

  6. Tandem mirror reactors

    International Nuclear Information System (INIS)

    Logan, B.G.; Barr, W.L.; Bender, D.J.

    1978-01-01

    We have made preliminary designs of tandem mirror fusion reactors burning D-T fuel and of fusion-fission (hybrid) tandem mirrors producing both fissile fuel and electricity. For the hybrid reactor, we find that by using stream-stabilized, 2XIIB-like plugs and by injecting 200-keV deuterium beams into a tritium-plasma target confined electrostatically in the solenoid (two-component operation), we obtain a useful Q (fusion power/injection power) near unity. The D-T tandem reactor parameters are optimized to obtain the minimum capital cost per kW(e) net. For $200/kW(e) of 1200-keV neutral beam injection power in the plugs and a solenoid cost of about $3 million per metre length, the optimum Q is near 5. To allow for more expensive injector costs, a higher D-T reactor Q of 10 is obtainable with either increased power output or decreased neutron wall loading. Fokker--Planck calculations show steady-state Q approximately 5 for D-D tandem reactors burning only deuterium fuel and its reaction products, with most of the charged-particle fusion power recovered in a direct converter

  7. Moment approach to tandem mirror radial transport

    International Nuclear Information System (INIS)

    Siebert, K.D.; Callen, J.D.

    1986-02-01

    A moment approach is proposed for the study of tandem mirror radial transport in the resonant plateau regime. The salient features of the method are described with reference to axisymmetric tokamak transport theory. In particular, the importance of momentum conservation to the establishment of the azimuthal variations in the electrostatic potential is demonstrated. Also, an ad hoc drift kinetic equation is solved to determine parallel viscosity coefficients which are required to close the moment system

  8. Axisymmetric magnetic mirrors for plasma confinement. Recent development and perspectives

    International Nuclear Information System (INIS)

    Kruglyakov, E.P.; Dimov, G.I.; Ivanov, A.A.; Koidan, V.S.

    2003-01-01

    Mirrors are the only one class of fusion systems which completely differs topologically from the systems with closed magnetic configurations. At present, three modern types of different mirror machines for plasma confinement and heating exist in Novosibirsk (Gas Dynamic Trap,- GDT, Multi-mirror,- GOL-3, and Tandem Mirror,- AMBAL-M). All these systems are attractive from the engineering point of view because of very simple axisymmetric geometry of magnetic configurations. In the present paper, the status of different confinement systems is presented. The experiments most crucial for the mirror concept are described such as a demonstration of different principles of suppression of electron heat conductivity (GDT, GOL-3), finding of MHD stable regimes of plasma confinement in axisymmetric geometry of magnetic field (GDT, AMBAL-M), an effective heating of a dense plasma by relativistic electron beam (GOL-3), observation of radial diffusion of quiescent plasma with practically classical diffusion coefficient (AMBAL-M), etc. It should be mentioned that on the basis of the GDT it is possible to make a very important intermediate step. Using 'warm' plasma and oblique injection of fast atoms of D and T one can create a powerful 14 MeV neutron source with a moderate irradiation area (about 1 square meter) and, accordingly, with low tritium consumption. The main plasma parameters achieved are presented and the future perspectives of different mirror machines are outlined. (author)

  9. Electrostatic axisymmetric mirror with removable spherical aberration

    International Nuclear Information System (INIS)

    Birmuzaev, S.B.; Serikbaeva, G.S.; Hizirova, M.A.

    1999-01-01

    The electrostatic axisymmetric mirror, assembled from three coaxial cylinders with an equal diameter d and under the potential v1, v2 and v3, was computed. The proportions of geometrical and electric parameters of the mirror, with which the spherical 3-order aberration may be eliminated, were determined. The computation outcomes of the case, when the focal power of the mirror is enough large and the object plane in the focus is out of its field, are presented (Fig. 1 - potentials proportion that makes elimination of the spherical aberration possible; Fig. 2 - the focus coordinates when the spherical aberration is eliminated). The geometrical values are presented by d, and the electric ones are presented by v1. The figures on the curves present a length of the second (middle) electrode. The zero point is located in the middle of the gap between the first and second electrodes The investigated mirror may be used as a lens for the transmission electron microscope

  10. Introduction to tandem mirror physics

    International Nuclear Information System (INIS)

    Kesner, J.; Gerver, M.J.; Lane, B.G.; McVey, B.D.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.

    1983-09-01

    This monograph, prepared jointly by the MIT Plasma Fusion Center Mirror Fusion group and SAI, Boulder, Colorado, presents a review of the development of mirror fusion theory from its conception some thirty years ago to the present. Pertinent historic experiments and their contribution are discussed to set the stage for a detailed analysis of current experiments and the problems which remain to be solved in bringing tandem mirror magnetic confinement fusion to fruition. In particular, Chapter III discusses in detail the equilibrium and stability questions which must be dealt with before tandem mirror reactors become feasible, while Chapters IV and V discuss some of the current machines and those under construction which will help to resolve critical issues in both physics and engineering whose solutions are necessary to the commercialization of tandem mirror fusion

  11. MHD stability of tandem mirrors

    International Nuclear Information System (INIS)

    Poulsen, P.; Molvik, A.; Shearer, J.

    1982-01-01

    The TMX-Upgrade experiment was described, and the manner in which various plasma parameters could be affected was discussed. The initial analysis of the MHD stability of the tandem mirror was also discussed, with emphasis on the negative tandem configuration

  12. Axisymmetric Magnetic Mirror Fusion-Fission Hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martovetsky, N. N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Molvik, A. W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ryutov, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simonen, T. C. [Univ. of California, Berkeley, CA (United States)

    2011-05-13

    The achieved performance of the gas dynamic trap version of magnetic mirrors and today’s technology we believe are sufficient with modest further efforts for a neutron source for material testing (Q=Pfusion/Pinput~0.1). The performance needed for commercial power production requires considerable further advances to achieve the necessary high Q>>10. An early application of the mirror, requiring intermediate performance and intermediate values of Q~1 are the hybrid applications. The Axisymmetric Mirror has a number of attractive features as a driver for a fusion-fission hybrid system: geometrical simplicity, inherently steady-state operation, and the presence of the natural divertors in the form of end tanks. This level of physics performance has the virtue of low risk and only modest R&D needed and its simplicity promises economy advantages. Operation at Q~1 allows for relatively low electron temperatures, in the range of 4 keV, for the DT injection energy ~ 80 keV. A simple mirror with the plasma diameter of 1 m and mirror-to-mirror length of 35 m is discussed. Simple circular superconducting coils are based on today’s technology. The positive ion neutral beams are similar to existing units but designed for steady state. A brief qualitative discussion of three groups of physics issues is presented: axial heat loss, MHD stability in the axisymmetric geometry, microstability of sloshing ions. Burning fission reactor wastes by fissioning actinides (transuranics: Pu, Np, Am, Cm, .. or just minor actinides: Np, Am, Cm, …) in the hybrid will multiply fusion’s energy by a factor of ~10 or more and diminish the Q needed to less than 1 to overcome the cost of recirculating power for good economics. The economic value of destroying actinides by fissioning is rather low based on either the cost of long-term storage or even deep geologic disposal so most of the revenues of hybrids will come from electrical power. Hybrids that obtain revenues from

  13. Tandem mirror technology demonstration facility

    International Nuclear Information System (INIS)

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M 2 ) on an 8-m 2 test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m 2 and give the necessary experience for successful operation of an ETR

  14. Tandem mirror technology demonstration facility

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    This report describes a facility for generating engineering data on the nuclear technologies needed to build an engineering test reactor (ETR). The facility, based on a tandem mirror operating in the Kelley mode, could be used to produce a high neutron flux (1.4 MW/M/sup 2/) on an 8-m/sup 2/ test area for testing fusion blankets. Runs of more than 100 h, with an average availability of 30%, would produce a fluence of 5 mW/yr/m/sup 2/ and give the necessary experience for successful operation of an ETR.

  15. 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.

  16. Designs of tandem-mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Barr, W.L.; Boghosian, B.M.

    1981-01-01

    We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability

  17. Edge diagnostics for tandem mirror machines

    International Nuclear Information System (INIS)

    Allen, S.L.

    1984-01-01

    The edge plasma in a tandem mirror machine shields the plasma core from cold neutral gas and impurities. A variety of diagnostics are used to measure the fueling, shielding, and confinement of the edge plasma in both the end plug and central cell regions. Fast ion gauges and residual gas analyzers measure the gas pressure and composition outside of the plasma. An array of Langmuir probes is used to measure the electron density and temperature. Extreme ultraviolet (euv) and visible spectroscopy are used to measure both the impurity and deuterium densities and to estimate the shielding factor for the core plasma. The linear geometry of a tandem mirror also allows direct measurements of the edge plasma by sampling the ions and electrons lost but the ends of the machine. Representative data obtained by these diagnostics during operation of the Tandem Mirror Experiment (TMX) and Tandem Mirror Experiment-Upgrade (TMX-U) experiments are presented. Diagnostics that are currently being developed to diagnose the edge plasma are also discussed

  18. The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?

    International Nuclear Information System (INIS)

    Post, R.F.

    2000-01-01

    ion beams are injected along the field lines in such a way as to be reflected before they reach the mirrors, thus forming a localized peak in the plasma density. It will be shown that the power required to produce these stabilizing plasmas is much less than the power per meter of fusion power systems that might employ this technique. Use of the Kinetic Stabilizer idea may therefore permit the construction of tandem mirror fusion power systems that are much smaller and simpler than those based on the use of non-axisymmetric fields to achieve MHD stability

  19. Tandem mirrors for neutron production

    International Nuclear Information System (INIS)

    Doggett, J.N.

    1983-01-01

    Two mirror machine concepts are being studied as early-time, low-cost, neutron-producing devices for testing and demonstrating reactor-relevant fusion technology. The first of these concepts is for a new, small, driven, steady-state, D-T reactor, called the Technology Demonstration Facility (TDF). The second concept is for upgrades to the MFTF-B machine that burn tritium and run for pulse lengths of some hours. Both devices operate in the Kelley mode in order to provide high-wall loadings of 14-MeV neutrons, thereby providing a valuable test bed for reactor-relevant hardware and subsystems. Either one of these devices could be running in the early 1990's with first wall fluxes between 1.4 and 2.0 MW m -2

  20. Plasma confinement in the TMX tandem mirror

    International Nuclear Information System (INIS)

    Hooper, E.B. Jr.; Allen, S.L.; Casper, T.A.

    1981-01-01

    Plasma confinement in the Tandem Mirror Experiment (TMX) is described. Axially confining potentials are shown to exist throughout the central 20-cm core of TMX. Axial electron-confinement time is up to 100 times that of single-cell mirror machines. Radial transport of ions is smaller than axial transport near the axis. It has two parts at large radii: nonambipolar, in rough agreement with predictions from resonant-neoclassical transport theory, and ambipolar, observed near the plasma edge under certain conditions, accompanied by a low-frequency, m = 1 instability or strong turbulence

  1. Electron cyclotron resonance heating of tandem mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Porkolab, M.

    1978-12-19

    Heating electrons by microwave power near either the electron cyclotron frequency or its harmonic is analyzed in some detail. The purpose of this study is to determine whether electrons in current or future mirror devices could be heated by electromagnetic waves in this frequency range. Absorption lengths, accessibility conditions, and appropriate polarization are among the concerns studied. It is found that the Tandem Mirror Experiment (TMX) may efficiently be heated by the extraordinary mode at omega = omega either in the solenoid-to-plug transition region or near the center of the plug at densities napprox. = 10/sup 13/cm/sup -3/.

  2. MHD-Stabilization of Axisymmetric Mirror Systems Using Pulsed ECRH

    International Nuclear Information System (INIS)

    Post, R.F.

    2010-01-01

    This paper, part of a continuing study of means for the stabilization of MHD interchange modes in axisymmertric mirror-based plasma confinement systems, is aimed at a preliminary look at a technique that would employ a train of plasma pressure pulses produced by ECRH to accomplish the stabilization. The purpose of using sequentially pulsed ECRH rather than continuous-wave ECRH is to facilitate the localization of the heated-electron plasma pulses in regions of the magnetic field with a strong positive field-line curvature, e. g. in the 'expander' region of the mirror magnetic field, outside the outermost mirror, or in other regions of the field with positive field-line curvature. The technique proposed, of the class known as 'dynamic stabilization,' relies on the time-averaged effect of plasma pressure pulses generated in regions of positive field-line curvature to overcome the destabilizing effect of plasma pressure in regions of negative field-line curvature within the confinement region. As will also be discussed in the paper, the plasma pulses, when produced in regions of the confining having a negative gradient, create transient electric potentials of ambipolar origin, an effect that was studied in 1964 in The PLEIDE experiment in France. These electric fields preserve the localization of the hot-electron plasma pulses for a time determined by ion inertia. It is suggested that it may be possible to use this result of pulsed ECRH not only to help to stabilize the plasma but also to help plug mirror losses in a manner similar to that employed in the Tandem Mirror.

  3. Progress in the tandem mirror program

    International Nuclear Information System (INIS)

    Fowler, T.K.; Borchers, R.R.

    1981-01-01

    Experimental results in TMX have confirmed the basic principles of the tandem-mirror concept. A center-cell particle confinement parameter eta tau approx. 10 11 cm -3 s has been obtained at ion temperatures around 100 eV, which is a hundred-fold improvement over single mirrors at the same temperatures. For TMX these results have been obtained at peak beta values in the center cell in the range 10 to 40%, not yet limited by MHD activity; and ion-cyclotron resonant heating (ICRH) in the Phaedrus tandem-mirror experiment has produced beta values approx. 25%, which is several times the ideal MHD limit for that device. In addition, it has been demonstrated that the end fan chambers of TMX simultaneously isolate the hot electrons from the end walls, provide adequate pumping and conveniently dispose of the exhaust plasma energy either by thermal deposition on the end wall or by direct conversion to electricity (at 48% efficiency in agreement with calculations). Also, evidence was obtained for inherent divertor action in TMX, presumably in part responsible for the observed low impurity level

  4. Physics issues in mirror and tandem mirror systems

    Energy Technology Data Exchange (ETDEWEB)

    Post, R.F.

    1984-06-15

    Over the years the study of the confinement of high temperature plasma in magnetic mirror systems has presented researchers with many unusual physics problems. Many of these issues are by now understood theoretically and documented experimentally. With the advent of the tandem mirror idea, some new issues have emerged and are now under intensive study. These include: (1) the generation and control of ambipolar confining potentials and their effect on axial confinement and, (2) the combined influence of nonaxisymmetric magnetic fields (used to ensure MHD stability) and electric magnetic particle drifts on radial transport. Physics considerations associated with these two categories of issues will be reviewed, including concepts for the control of radial transport, under study or proposed.

  5. Tandem mirror and tokamak reactor maintainability comparison

    International Nuclear Information System (INIS)

    Zahn, H.S.

    1981-01-01

    The analysis proceeds through estimates of downtime and resources required for selected maintenance actions and optimization of the replacement fraction, availability and cost of electricity. Scheduled downtime estimates and availability goals provide a basis for determining allowable forced outage downtimes. These analyses have been conducted with the assumption of redundancy wherever feasible but without the impact of maintenance equipment outages. Annual maintenance cost estimates and availabilities for both reactors are found to be approximately equal. However, the tandem mirror reactor capital costs are higher. Reduction of these costs appears feasible with the trend of current design studies toward smaller and more accessible machines

  6. Parametric systems analysis for tandem mirror hybrids

    International Nuclear Information System (INIS)

    Lee, J.D.; Chapin, D.L.; Chi, J.W.H.

    1980-09-01

    Fusion fission systems, consisting of fissile producing fusion hybrids combining a tandem mirror fusion driver with various blanket types and net fissile consuming LWR's, have been modeled and analyzed parametrically. Analysis to date indicates that hybrids can be competitive with mined uranium when U 3 O 8 cost is about 100 $/lb., adding less than 25% to present day cost of power from LWR's. Of the three blanket types considered, uranium fast fission (UFF), thorium fast fission (ThFF), and thorium fission supressed (ThFS), the ThFS blanket has a modest economic advantage under most conditions but has higher support ratios and potential safety advantages under all conditions

  7. Remote maintenance of tandem mirror hybrid coils

    International Nuclear Information System (INIS)

    Dietz, L.P.

    1983-01-01

    Hybrid Coils (superconducting coils with normal conducting inserts) are being employed with increasing frequency on Tandem Mirror Devices to obtain high field strengths. The normal conducting copper inserts are short lived in comparison to their encircling superconductors. It becomes desirable, therefore, to devise design features and maintenance procedures to replace the inner normal conducting coils without simultaneously replacing the longer lived (and significantly more costly) superconducting coils. The high neutron wall loadings require that the task be accomplished by remote control. The approach is to permanently mount the coil assemblies on track mounted carriages which serve, during machine operation merely as structural supports, but during maintenance procedures as moveable transport devices. The carriages incorporate all necessary provisions to facilitate remote maintenance operations and to adjust and align the coil assemblies with respect to adjacent machine components. The vacuum vessel is severed on both sides of the hybrid coil by means of a remote cutting machine. The entire coil is transported horizontally, normal to the machine axis to a nearby repair station. Prepositioned carriage mounted repair equipment at the repair station withdraws the damaged normal coil as a single entity and inserts a preassembled spare unit. The repaired hybrid coil is reassembled to the reactor. A cost and risk effective procedure has been evolved to maintain one of the more critical components of a Tandem Mirror Machine

  8. Engineering problems of tandem-mirror reactors

    International Nuclear Information System (INIS)

    Moir, R.W.; Barr, W.L.; Boghosian, B.M.

    1981-01-01

    We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability. This paper discusses some of the many engineering problems facing the designer. We estimated the direct cost to be 2$/W/sub e/. Assuming total (direct and indirect) costs to be twice this number, we need to reduce total costs by factors between 1.7 and 2.3 to compete with future LWRs levelized cost of electricity. These reductions may be possible by designing magnets producing over 20T made possible by use of combinations of superconducting and normal conducting coils as well as improvements in performance and cost of neutral beam and microwave power systems. Scientific and technological understanding and innovation are needed in the area of thermal barrier pumping - a process by which unwanted particles are removed (pumped) from certain regions of velocity and real space in the end plug. Removal of exhaust fuel ions, fusion ash and impurities by action of a halo plasma and plasma dump in the mirror end region is another challenging engineering problem discussed in this paper

  9. Tandem mirror magnet system for the mirror fusion test facility

    International Nuclear Information System (INIS)

    Bulmer, R.H.; Van Sant, J.H.

    1980-01-01

    The Tandem Mirror Fusion Test Facility (MFTF-B) will be a large magnetic fusion experimental facility containing 22 supercounducting magnets including solenoids and C-coils. State-of-the-art technology will be used extensively to complete this facility before 1985. Niobium titanium superconductor and stainless steel structural cases will be the principle materials of construction. Cooling will be pool boiling and thermosiphon flow of 4.5 K liquid helium. Combined weight of the magnets will be over 1500 tonnes and the stored energy will be over 1600 MJ. Magnetic field strength in some coils will be more than 8 T. Detail design of the magnet system will begin early 1981. Basic requirements and conceptual design are disclosed in this paper

  10. Tandem mirror reactor power balance studies

    International Nuclear Information System (INIS)

    Gorker, G.E.; Perkins, L.J.

    1985-01-01

    A tandem mirror reactor (TMR) power plant balance model has been developed and is now being used as a computer aid for performing parametric studies. End-cell power injection into the plasma and the physics thermal Q are used to determine the fusion power. About 80% of the fusion power is transferred by high-energy neutrons to the blanket modules and structures. The other 20% of the fusion power in the high-energy alpha particles is used to heat the deuterium-tritium (D-T) plasma. Most of the plasma-ionized particles transfer their energy to the halo dumps and direct converters. The plant efficiency is calculated for three different system cycles: (1) the pressurized water/saturated steam cycle; (2) the superheated steam cycle; and (3) the more complex superheat/reheat cycle. There is a signficiant improvement in plant efficiency as the electrical power multiplication factor and steam cycle efficiency increases

  11. Vacuum system for the Tandem Mirror Experiment

    International Nuclear Information System (INIS)

    Richardson, M.J.; Atkinson, D.P.; Calderon, M.O.

    1979-01-01

    This paper is a sequel to the one prepared by Atkinson, et al., in which the authors described the vacuum system of Lawrence Livermore Laboratory's Tandem Mirror Experiment (TMX). We discuss here the final configuration, liquid nitrogen (LN 2 ) supply, and operation of the complete TMX vacuum system. The assembled vacuum system consists of two plug tanks with a volume of approximately 60 m 3 each and a center cell tank with a volume of approximately 10 m 3 . In each plug tank there are 145 m 2 of titanium-gettered, LN 2 -filled panels, which allow a pumping speed calculated to be 5 x 10 7 l/s for a period of 50 ms. The system maintains an operating pressure in the plasma chamber on the order of 10 -6 Torr while 24 neutral-beam injectors are introducing 700 Torr l/s of hydrogen into the vacuum chamber

  12. Status of tandem-mirror confinement

    International Nuclear Information System (INIS)

    Baldwin, D.E.

    1983-01-01

    Recent end-stopping experiments in TMX-Upgrade show strong plugging of the central cell by lower-density plugs, requiring both electron-cyclotron heating (ECRH) and 47 0 neutral-beam injection, consistent with the thermal-barrier concept. These experiments have low density (n 12 cm -3 ) due to inefficient ECRH power coupling. Hot-ion and hot-electron buildup are consistent with Fokker-Planck calculations. No ion-cyclotron activity is observed in the plugs; occasional electron-cyclotron activity is observed. With plugging, axial lifetimes (tau/sub parallel/ > 40 ms) are larger than radial (tau/sub perpendicular/ = 5 to 10 ms) due to observed non-ambipolar ion transport. Recent tandem-mirror theoretical activities are also surveyed

  13. Results from the Tara tandem mirror experiment

    International Nuclear Information System (INIS)

    Lane, B.G.

    1987-09-01

    A summary of the experimental results from the Tara tandem mirror experiment is presented. Optimization of the fueling configuration, slow wave ion cyclotron heating from a magnetic ''plateau'' using an aperture antenna design, and enhanced stabilization from a magnetic divertor have allowed the attainment of a stable start up plasma (T/sub i,perpendicular/ = 800 - 1500 eV, n/sub e/ = 4 - 5 x 10 12 cm -3 , T/sub e/ = 70 - 80 eV). Plugging experiments using radiofrequency waves near the plug midplane ion cyclotron frequency have proved successful in reducing endloss, while simultaneously leading to an increase in central cell density. The plugging potentials have been limited to approximately the ion parallel temperature. This limitation is due to low frequency instabilities localized in the plug. Axial plugging experiments using electron cyclotron (ECH) resonant microwave radiation in the plug cells have had ambiguous results. Endloss reductions up to 100% have been achieved without build-up of central cell densities or the appearance of the reflected particles at the other end of the machine. We conjecture that rapid radial losses accompany the use of ECH, although the mechanisms for this loss remain unidentified. 9 refs., 9 figs

  14. Design of tandem mirror reactors with thermal barriers

    International Nuclear Information System (INIS)

    Carlson, G.A.

    1980-01-01

    End-plug technologies for tandem mirror reactors include high-field superconducting magnets, neutral beam injectors, and gyrotrons for electron cyclotron resonant heating (ECRH). In addition to their normal use for sustenance of the end-plug plasmas, neutral beam injectors are used for ''pumping'' trapped ions from the thermal barrier regions by charge exchange. An extra function of the axially directed pump beams is the removal of thermalized alpha particles from the reactor. The principles of tandem mirror operation with thermal barriers will be demonstrated in the upgrade of the Tandem Mirror Experiment (TMX-U) in 1981 and the tandem configuration of the Mirror fusion Test Facility (MFTF-B) in 1984

  15. Characterization of a medium-sized washer-gun for an axisymmetric mirror

    Science.gov (United States)

    Yi, Hongshen; Liu, Ming; Shi, Peiyun; Yang, Zhida; Zhu, Guanghui; Lu, Quanming; Sun, Xuan

    2018-04-01

    A new medium-sized washer gun is developed for a plasma start-up in a fully axisymmetric mirror. The gun is positioned at the east end of the Keda Mirror with AXisymmetricity facility and operated in the pulsed mode with an arc discharging time of 1.2 ms and a typical arc current of 8.5 kA with 1.5 kV discharge voltage. To optimize the operation, a systematic scan of the neutral pressure, the arc voltage, the bias voltage on a mesh grid 6 cm in front of the gun and an end electrode located on the west end of mirror, and the mirror ratio was performed. The streaming plasma was measured with triple probes in the three mirror cells and a diamagnetic loop in the central cell. Floating potential measurements suggest that the plasma could be divided into streaming and mirror-confined plasmas. The floating potential for the streaming plasma is negative, with an electric field pointing inwards. The mirror-confined plasma has a typical lifetime of 0.5 ms.

  16. Stochastic motion of particles in tandem mirror devices

    International Nuclear Information System (INIS)

    Ichikawa, Y.H.; Kamimura, T.

    1982-01-01

    Stochastic motion of particles in tandem mirror devices is examined on basis of a nonlinear mapping of particle positions on the equatorial plane. Local stability analysis provides detailed informations on particle trajectories. The rate of stochastic plasma diffusion is estimated from numerical observations of motions of particles over a large number of time steps. (author)

  17. Interim report on the tandem mirror hybrid design study

    International Nuclear Information System (INIS)

    Moir, R.W.

    1979-01-01

    The initial phase of a 2-year design study of a tandem mirror fusion reactor is presented. The following chapters are included: (1) mechanical design of the plant; (2) plasma physics; (3) blanket design; (4) magnet design; (5) injector design; (6) direct convertor design; (7) balance of plant design; (8) fission burner reactor; (9) environment and safety; and (10) economic analysis

  18. Impurity diagnostics in the GAMMA 10 tandem mirror

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, M.; Okamoto, Y.; Kawamori, E.; Ito, T.; Watabe, C.; Watanabe, Y.; Tamano, T. [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Ikeda, K. [National Inst. for Fusion Science, Toki, Gifu (Japan); Yamaguchi, N. [Toyota Technological Institute, Nagoya, Aichi (Japan)

    2000-01-01

    We have constructed spectroscopic measurement systems in the wavelength range from soft X-ray to visible lights. We observed absolute impurity line intensities, Doppler line broadenings and Doppler shifts of impurity lines and time dependent radial profiles of the impurity lines in the GAMMA 10 tandem mirror. (author)

  19. Interim report on the tandem mirror hybrid design study

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W. (ed.)

    1979-08-01

    The initial phase of a 2-year design study of a tandem mirror fusion reactor is presented. The following chapters are included: (1) mechanical design of the plant; (2) plasma physics; (3) blanket design; (4) magnet design; (5) injector design; (6) direct convertor design; (7) balance of plant design; (8) fission burner reactor; (9) environment and safety; and (10) economic analysis. (MOW)

  20. Overview and direction in the tandem mirror program

    International Nuclear Information System (INIS)

    Thomassen, K.I.

    1983-04-01

    There are two main thrusts to the tandem mirror program at the present time. One is to gather the experimental data base to verify the axicell thermal-barrier concept and the other to improve the end plugs for tandems. With such improvements one might approach the ideal fusion reactor, a simple solenoid of modular elements whose ends are but a modest perturbation on the configuration from both a cost and technological viewpoint. Progress toward these two goals is discussed here, and the directions to be taken in the immediate future are described

  1. ECE diagnostic for the TARA tandem mirror machine using a fast-scanning Michelson interferometer

    International Nuclear Information System (INIS)

    Guharay, S.K.; Boyd, D.A.; Ellis, R.F.

    1986-01-01

    This ECE (electron cyclotron emission) diagnostic utilizes a fast-scanning Michelson interferometer to determine two parameters, the temperature and the loss cone angle, of the distribution function of the hot electrons (Tapprox. >100 keV) generated in the axisymmetric plug plasma of the TARA tandem mirror device. The radiation transport system employs a lens relay and a low-pass grating filter in order to transmit the synchrotron radiation over a spectral range of 2.9--18.6 cm -1 . This enables us to study the emitted radiation spectrum up to the 40th harmonic of the electron--cyclotron frequency in the plug plasma (B = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented

  2. Summary of results from the Tandem Mirror Experiment (TMX)

    Energy Technology Data Exchange (ETDEWEB)

    Simonen, T.C. (ed.)

    1981-02-26

    This report summarizes results from the successful experimental operation of the Tandem Mirror Experiment (TMX) over the period October 1978 through September 1980. The experimental program, summarized by the DOE milestones given in Table 1-1, had three basic phases: (1) an 8-month checkout period, October 1978 through May 1979; (2) a 6-month initial period of operation, June through November 1979, during which the basic principles of the tandem configuration were demonstrated (i.e., plasma confinement was improved over that of a single-cell mirror); and (3) a 10-month period, December 1979 through September 1980, during which the initial TMX results were corroborated by additional diagnostic measurements and many detailed physics investigations were carried out. This report summarizes the early results, presents results of recent data analysis, and outlines areas of ongoing research and data analysis which will be reported in future journal publications.

  3. Summary of results from the Tandem Mirror Experiment (TMX)

    International Nuclear Information System (INIS)

    Simonen, T.C.

    1981-01-01

    This report summarizes results from the successful experimental operation of the Tandem Mirror Experiment (TMX) over the period October 1978 through September 1980. The experimental program, summarized by the DOE milestones given in Table 1-1, had three basic phases: (1) an 8-month checkout period, October 1978 through May 1979; (2) a 6-month initial period of operation, June through November 1979, during which the basic principles of the tandem configuration were demonstrated (i.e., plasma confinement was improved over that of a single-cell mirror); and (3) a 10-month period, December 1979 through September 1980, during which the initial TMX results were corroborated by additional diagnostic measurements and many detailed physics investigations were carried out. This report summarizes the early results, presents results of recent data analysis, and outlines areas of ongoing research and data analysis which will be reported in future journal publications

  4. Neutral beam control systems for the Tandem Mirror Experiment

    International Nuclear Information System (INIS)

    Ross, R.I.

    1979-01-01

    The Tandem Mirror Experiment (TMX) is presently developing the technology and approaches which will be used in larger fusion systems. This paper describes some of the designs which were used in creating the control system for the TMX neutral beams. To create a system of controls that would work near these large, rapid switching current sources required a mixture of different technologies: fiberoptic data transmission, printed circuit and wirewrap techniques, etc

  5. Preliminary design of a Tandem-Mirror-Next-Step facility

    International Nuclear Information System (INIS)

    Damm, C.C.; Doggett, J.N.; Bulmer, R.H.

    1980-01-01

    The Tandem-Mirror-Next-Step (TMNS) facility is designed to demonstrate the engineering feasibility of a tandem-mirror reactor. The facility is based on a deuterium-tritium (D-T) burning, tandem-mirror device with a fusion power output of 245 MW. The fusion power density in the central cell is 2.1 MW/m 3 , with a resultant neutron wall loading of 0.5 MW/m 2 . Overall machine length is 116 m, and the effective central-cell length is 50.9 m. The magnet system includes end cells with yin-yang magnets to provide magnetohydrodynamic (MHD) stability and thermal-barrier cells to help achieve a plasma Q of 4.7 (where Q = fusion power/injected power). Neutral beams at energies up to 200 keV are used for plasma heating, fueling, and barrier pumping. Electron cyclotron resonant heating at 50 and 100 GHz is used to control the electron temperature in the barriers. Based on the resulting engineering design, the overall cost of the facility is estimated to be just under $1 billion. Unresolved physics issues include central-cell β-limits against MHD ballooning modes (the assumed reference value of β exceeds the current theory-derived limit), and the removal of thermalized α-particles from the plasma

  6. Evolution of the Fusion Power Demonstration tandem mirror reactor configuration

    International Nuclear Information System (INIS)

    O'Toole, J.A.; Lousteau, D.C.

    1985-01-01

    This paper gives a presentation of the evolution of configurations proposed for tandem mirror Fusion Power Demonstration (FPD) machines. The FPD study was undertaken to scope the mission as well as the technical and design requirements of the next tandem mirror device. Three configurations, entitled FPD I, II, and III were studied. During this process new systems were conceived and integrated into the design, resulting in a significantly changed overall machine configuration. The machine can be divided into two areas. A new center cell configuration, minimizing magnetic field ripple and thus maximizing center cell fusion power, features a semicontinuous solenoid. A new end cell has evolved which maintains the required thermal barrier in a significantly reduced axial length. The reduced end cell effective length leads to a shorter central cell length being required to obtain minimum ignition conditions. Introduced is the concept of an electron mantle stabilized octopole arrangement. The engineering features of the new end cell and maintenance concepts developed are influenced to a great extent by the octopole-based design. The new ideas introduced during the FPD study have brought forth a new perspective of the size, design, and maintenance of tandem mirror reactors, making them more attractive as commercial power sources

  7. Investigation of barrier cell and auxilliary heating in a tandem mirror. Annual progress report, October 1, 1979-September 30, 1980

    International Nuclear Information System (INIS)

    Kesner, J.; Emmert, G.A.; Howard, J.E.

    1980-06-01

    A number of areas relating to RF heating and thermal barrier formation in a tandem mirror have been investigated. The possibility of creating axisymmetric confinement through the use of sloshing-ions has been investigated. We have also suggested the complimentary concept of sloshing-electrons. Self-consistent thermal barrier formation has been studied and ion drift orbits in non-axisymmetric barriers are being investigated. The study of dynamic stabilization of the DCLC by RF fields has been extended to ω near 2 ω/sub ci/; significant stabilization is found. Fast and slow wave heating have been extensively studied using single particle theory. A new theory of relativistic ECH is under development

  8. Mechanical design aspects of a tandem mirror fusion reactor

    International Nuclear Information System (INIS)

    Neef, W.S. Jr.

    1977-01-01

    Two ''plugs'' of dense plasma at either end of a central solenoid cell form the basis of a new mirror fusion power plant concept. A central cell blanket design is presented. Modules on crawler tracks serviced by remote welding and handling machines of very simple design are important features resulting from linear axisymmetric geometry. Three blanket designs are considered and the best one presented in some detail. It has lithium as the breeder material, helium cooled. ''Plug'' magnet field strengths must be high. A novel magnet is presented to satisfy the physics of the end plugs. Beam sources at 1,200 KV present special problems. Methods of voltage standoff, arc damage control, and neutralization are discussed. New secondary containment ideas are presented to allow removable roof sections of balanced design

  9. Tandem mirror reactor studies at Lawrence Livermore National Laboratory, FY 1980

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, G.A.; Neef, W.S. Jr.

    1981-03-20

    The principles of tandem mirror operation with thermal barriers will be demonstrated in the upgrade of the Tandem Mirror Experiment (TMX-U) in 1981 and the tandem configuration of the Mirror Fusion Test Facility (MFTF-B) in 1984. Continued analysis and conceptual design over this period will evolve the optimal configuration and parameters for a power-producing reactor. In this article we describe the progress we have made in this reactor design study effort during 1980.

  10. Orbit averaged radial buildup code for tandem mirror geometry

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, M.; Futch, A.H.

    1981-01-22

    The radial Fokker-Planck (RFP) model of A. Futch was modified to treat plasma buildup in the tandem mirror plug and center cell with a self-consistent model (TOARBUC). Two major changes have been made to the original version of this code. First, the center cell is treated as having separate electron and ion confining potentials with the ion potential having the opposite sign of that in a conventional mirror. Second, a two-electron-temperature treatment derived by R. Cohen was included in the present model to allow the plug and center cell to have different T/sub e/'s as observed in the experiment. The following sections explain these changes in greater detail.

  11. Physics-magnetics trade studies for tandem mirror reactors

    International Nuclear Information System (INIS)

    Campbell, R.B.; Perkins, L.J.; Blackfield, D.T.

    1985-01-01

    We describe and present results obtained from the optimization package of the Tandem Mirror Reactor Systems Code. We have found it to be very useful in searching through multidimensional parameter space, and have applied it here to study the effect of choke coil field strength and net electric power on cost of electricity (COE) and mass utilization factor (MUF) for MINIMARS type reactors. We have found that a broad optimum occurs at B/sub choke/ = 26 T for both COE and MUF. The COE economy of scale approaches saturation at quite low powers, around 600 MW(e). The saturation is mainly due to longer construction times for large plants, and the associated time related costs. The MUF economy of scale does not saturate, at least for powers up to 2400 MW(e)

  12. Investigation of recycling in the GAMMA 10 tandem mirror

    International Nuclear Information System (INIS)

    Nakashima, Y.; Yatsu, K.; Tsuchiya, K.; Ichimura, M.; Yamaguchi, N.; Inutake, M.; Shoji, M.; Ohtoshi, K.; Tamano, T.; Miyoshi, S.

    1992-01-01

    This paper describes the detailed behavior of particle recycling on the stainless-steel wall of the GAMMA 10 tandem mirror device. A comparison is made with a model calculation. The ion temperature dependence of the recycling coefficients has been deduced from experimental data in a wall conditioning period. It was found that the recycling coefficient increased with the ion temperature and that the recycling due to particles desorbed from the wall prevailed over that due to wall-reflection. A simple recycling model including both atomic and molecular processes was applied for the ICRF-heated plasma. The result of the model calculation is consistent with the above ion-temperature dependence. The DEGAS neutral transport code has been applied to the GAMMA 10 configuration and the results of the DEGAS code show a good agreement with results obtained from H α -emission, which predicted a significant influence due to neutral molecules near the plasma boundary. (orig.)

  13. Preliminary pellet injection experiment in the Gamma 10 tandem mirror

    Energy Technology Data Exchange (ETDEWEB)

    Kawamori, Eiichirou; Tamano, Teruo; Nakashima, Yousuke; Yoshikawa, Masayuki; Kobayashi, Shinji; Cho, Teruji; Ishii, Kameo; Yatsu, Kiyoshi [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Mase, Atsushi [Advanced Sceince and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka (Japan)

    2000-07-01

    In the GAMMA 10 tandem mirror, pellet injection experiments have been started as a solution for the density limit problem. This is the first pellet injection experiment in open systems. We describe the possibilities of confinement of pellet fueled particles. For that, we measure the number of end loss particles and compare them with pellet fueled ones in various conditions of confining potentials. The deterioration of confining potential with the pellet injection is a fundamental issue. The results show that the ion confining potential recover faster than central electron temperature due to thermal barrier. We also consider the operating space for fueling method. It is demonstrated that the operating space for pellet injection exceeds gas fueled one on hot ion mode plasmas. (author)

  14. LLNL Tandem Mirror Experiment (TMX) upgrade vacuum system

    International Nuclear Information System (INIS)

    Pickles, W.L.; Chargin, A.K.; Drake, R.P.

    1981-01-01

    TMX Upgrade is a large, tandem, magnetic-mirror fusion experiment with stringent requirements on base pressure (10 -8 torr), low H reflux from the first walls, and peak gas pressure (5 x 10 -7 torr) due to neutral beam gas during plasma operation. The 225 m 3 vacuum vessel is initially evacuated by turbopumps. Cryopumps provide a continuous sink for gases other than helium, deuterium, and hydrogen. The neutral beam system introduces up to 480 l/s of H or D. The hydrogen isotopes are pumped at very high speed by titanium sublimed onto two cylindrical radially separated stainless steel quilted liners with a total surface area of 540 m 2 . These surfaces (when cooled to about 80 0 K) provide a pumping speed of 6 x 10 7 l/s for hydrogen. The titanium getter system is programmable and is used for heating as well as gettering. The inner plasma liner can be operated at elevated temperatures to enhance migration of gases away from the surfaces close to the plasma. Glow discharge cleaning is part of the pumpdown procedure. The design features are discussed in conjunction with the operating procedures developed to manage the dynamic vacuum conditions

  15. WITAMIR-I: A tandem mirror power reactor

    International Nuclear Information System (INIS)

    Emmert, G.A.; Kulcinski, G.L.; Beyer, J.B.

    1983-01-01

    A conceptual design of a near term commercial tandem mirror power reactor will be presented. The basic configuration utilizes Yin-yang minimum B end plugs with inboard thermal barriers, which are pumped by neutral beam injection. The maximum magnetic fields are 6.1 T, 8.1 T and 15 T in the central cell, Yin-yang, and thermal barrier magnets, respectively. The blanket utilizes Pb 83 Li 17 as the coolant and breeder, and HT-9 as the structural material. This configuration yields a high energy multiplication (1.37), a sufficient tritium breeding ratio (1.07) and has a major advantage with respect to maintenance. A single stage direct convertor is used at one end and an electron thermal dump at the other end. The plasma Q is 28 at a fusion power level of 3000 MWsub(th); the net electrical output is 1530 MWe and the overall efficiency is 39%. Cost estimates indicate that WITAMIR-I is competitive with recent tokamak power reactor designs. (author)

  16. Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

    International Nuclear Information System (INIS)

    Werner, R.W.; Ribe, F.L.

    1981-01-01

    This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units

  17. TMX-U [Tandem Mirror Experiment-Upgrade]: Final report, Volume 2

    International Nuclear Information System (INIS)

    Porter, G.D.

    1988-01-01

    This paper discusses the plasma control and the physics accomplishments of the Tandem Mirror Experiment-Upgrade. This particular volume discusses fueling, ion heating, Fokker-Planck modeling, plasma stability and technical development. 270 refs

  18. TMX-U [Tandem Mirror Experiment-Upgrade]: Final report, Volume 1

    International Nuclear Information System (INIS)

    Porter, G.D.

    1988-01-01

    This paper discusses the plasma control and the physics accomplishments of the Tandem Mirror Experiment-Upgrade. This particular volume discusses potential measurements, plasma confinement, and hot electron and ion physics. 230 refs

  19. Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

    Energy Technology Data Exchange (ETDEWEB)

    Werner, R.W.; Ribe, F.L.

    1981-01-21

    This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units. (MOW)

  20. Influence of the shear flow on electron cyclotron resonance plasma confinement in an axisymmetric magnetic mirror trap of the electron cyclotron resonance ion source

    International Nuclear Information System (INIS)

    Izotov, I. V.; Razin, S. V.; Sidorov, A. V.; Skalyga, V. A.; Zorin, V. G.; Bagryansky, P. A.; Beklemishev, A. D.; Prikhodko, V. V.

    2012-01-01

    Influence of shear flows of the dense plasma created under conditions of the electron cyclotron resonance (ECR) gas breakdown on the plasma confinement in the axisymmetric mirror trap (''vortex'' confinement) was studied experimentally and theoretically. A limiter with bias potential was set inside the mirror trap for plasma rotation. The limiter construction and the optimal value of the potential were chosen according to the results of the preliminary theoretical analysis. This method of ''vortex'' confinement realization in an axisymmetric mirror trap for non-equilibrium heavy-ion plasmas seems to be promising for creation of ECR multicharged ion sources with high magnetic fields, more than 1 T.

  1. Reactor issues for tandem mirrors operating in the negative-potential mode

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, L.J.; Campbell, R.B.

    1985-12-02

    During 1985, interest has been revived at LLNL in tandem mirrors operating in the negative-potential mode. The negative tandem is formed by combining ECRH-sustained hot electron end cell plasmas with pumping mechanisms to remove trapped ions from the end cells. No sloshing ions are required. The resulting negative potential in the end cells confines the central cell electrons. The requirement of charge neutrality causes the ambipolar potential of the central cell to become negative relative to the end wall (hence, the name ''negative' tandem mirror), thereby providing central cell ion confinement. This potential distribution is the exact inverse of the axial distribution for the conventional (positive) tandem mirror without thermal barriers. In the negative tandem mirror, central cell electrons are confined electrostatically, end cell electrons are confined magnetically, and ions are confined electrostatically everywhere. In this report, we briefly assess the reactor issues pertinent to the operation of the tandem mirror in the negative mode. 7 refs., 5 figs.

  2. Construction and operational experience of the Tandem Mirror Experiment-Upgrade (TMX-U)

    International Nuclear Information System (INIS)

    Chargin, A.K.; Calderon, M.O.; Moore, T.L.

    1983-01-01

    The Tandem Mirror Experiment-Upgrade (TMX-U) incorporates two new features at Lawrence Livermore National Laboratory (LLNL) tandem mirror program, thermal barriers in the end plugs and injection of the neutral beams at several oblique angles. The thermal barriers isolate the electrons in the end plugs from those in the central cell, making it possible to heat them independently with microwaves. In addition, this innovation produces a large potential gradient in the end plugs with lower magnetic fields and lower neutral-beam energies than would be possible in a conventional tandem mirror device. The TMX-U is also designed to test neutral-beam-injection angles as an experimental parameter. We use angles other than 90 0 to produce a plasma with improved microstability

  3. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    International Nuclear Information System (INIS)

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-01-01

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented

  4. Status of the Tandem Mirror Experiment-Upgrade (TMX-U) diagnostic system

    International Nuclear Information System (INIS)

    Coutts, G.W.; Coffield, F.E.; Hornady, R.S.

    1983-01-01

    This paper presents the current status of the Tandem Mirror Experiment-Upgrade (TMX-U) diagnostics system. For the initial instruments active on TMX-U, the expansions or upgrades that have been implemented are outlined. For the newly added systems, more implementation details are presented

  5. Monte Carlo particle simulation and finite-element techniques for tandem mirror transport

    International Nuclear Information System (INIS)

    Rognlien, T.D.; Cohen, B.I.; Matsuda, Y.; Stewart, J.J. Jr.

    1985-12-01

    A description is given of numerical methods used in the study of axial transport in tandem mirrors owing to Coulomb collisions and rf diffusion. The methods are Monte Carlo particle simulations and direct solution to the Fokker-Planck equations by finite-element expansion. 11 refs

  6. Preliminary results in double cusp tandem mirror MM-4U

    International Nuclear Information System (INIS)

    Ming Linzhou; Tian Zhongyu; Feng Xiaozhen

    1990-10-01

    MM-4U device and preliminary experimental results are presented. Main results are as follows: The plasma has been produced by means of the injection of strong electron current; the axial profile of the plasma potential and the plasma electron density have been obtained respectively, they had a simular form; the plasma potential in the centre of the east cusp, the west cusp and the simple mirror; V e = -180V, V w = -164V, V m -1.8V; the electron density: n e = 1.7 x 10 11 cm -3 , n w = 4.7 x 10 10 cm -3 , n m = 7.5 x 10 7 cm -3 ; the electron temperature: T e = (19.9 ± 1.6) eV, T w = (20.7 ± 1.7) eV; the plasma pressure at 8 cm on the right of the west cusp centre is about 6.76 Pa, β ≅ 1.7 x 10 -3 . The plasma instability has been observed in the simple mirror, its vibration frequency was 7∼9.2 kHz. The results are discussed. The next new task of the physical experiment are proposed

  7. Design of an 18 Tesla, tandem mirror, fusion reactor, hybrid choke coil

    International Nuclear Information System (INIS)

    Parmer, J.F.; Agarwal, K.; Gurol, H.; Mancuso, A.; Michels, P.H.; Peck, S.D.; Burgeson, J.; Dalder, E.N.

    1987-01-01

    A hybrid, part normal part superconducting 18-Tesla solenoid choke coil is designed for a tandem mirror fusion reactor. The present state of the art is represented by the 12-Tesla, superconducting NbSn coil. Future applications other than tandem mirror fusion devices needing high field solenoids might require hybrid magnets of the type described herein. The hybrid design was generated because of critical field performance limitations on present, practical superconducting wires. A hybrid design might be required (due to structural limits) even if the critical field were higher. Also, hybrids could be a cost-effective way of getting very high fields for certain applications. The 18-Tesla solenoid described is composed of an inner coil made of water-cooled, high-strength zirconium copper which generates 3 Tesla. A superconducting NbSn background coil contributes the remaining 15 Tesla. The focus of the design study was on the inner coil. Demonstration fabrication and testing was performed

  8. A mechanical device for enhancing the halo density in the TMX-U tandem mirror

    International Nuclear Information System (INIS)

    Hsu, W.L.; Barr, W.L.; Simonen, T.C.

    1984-01-01

    The halo recycler, a mechanical device similar to pump limiters used in tokamaks, is studied as a means of enhancing the halo plasma density in the Tandem Mirror Experiment Upgrade (TMX-U). The recycler structure consists of an annular chamber at each end of the tandem mirror device where the halo plasma is collected. The halo plasma density is increased by recycling the halo ions as they are neutralized by the collector plate. With sufficient power fed into the halo electrons, the recycler can sustain an upstream electron temperature of 30 eV for effective halo shielding while maintaining a low temperature of 5 eV near the collector plate to reduce sputtering. A power flow model has shown that the required power for heating the halo is low enough to make the halo recycler a practical concept. (orig.)

  9. Synfuels from fusion: using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

    International Nuclear Information System (INIS)

    Werner, R.W.

    1982-01-01

    This study is concerned with the following area: (1) the tandem mirror reactor and its physics; (2) energy balance; (3) the lithium oxide canister blanket system; (4) high-temperature blanket; (5) energy transport system-reactor to process; (6) thermochemical hydrogen processes; (7) interfacing the GA cycle; (8) matching power and temperature demands; (9) preliminary cost estimates; (10) synfuels beyond hydrogen; and (11) thermodynamics of the H 2 SO 4 -H 2 O system

  10. Materials considerations for the coupling of thermochemical hydrogen cycles to tandem mirror reactors

    International Nuclear Information System (INIS)

    Krikorian, O.H.

    1980-01-01

    Candidate materials are discussed and initial choices made for the critical elements in a liquid Li-Na Cauldron Tandem Mirror blanket and the General Atomic Sulfur-Iodine Cycle for thermochemical hydrogen production. V and Ti alloys provide low neutron activation, good radiation damage resistance, and good chemical compatibility for the Cauldron design. Aluminide coated In-800H and siliconized SiC are materials choices for heat exchanger components in the thermochemical cycle interface

  11. Synfuels from fusion: using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Werner, R.W. (ed.)

    1982-11-01

    This study is concerned with the following area: (1) the tandem mirror reactor and its physics; (2) energy balance; (3) the lithium oxide canister blanket system; (4) high-temperature blanket; (5) energy transport system-reactor to process; (6) thermochemical hydrogen processes; (7) interfacing the GA cycle; (8) matching power and temperature demands; (9) preliminary cost estimates; (10) synfuels beyond hydrogen; and (11) thermodynamics of the H/sub 2/SO/sub 4/-H/sub 2/O system. (MOW)

  12. Feasibility study of a fission-suppressed tandem-mirror hybrid reactor

    International Nuclear Information System (INIS)

    Lee, J.D.; Moir, R.W.; Barr, W.L.

    1982-04-01

    Results of a conceptual design study of a U-233 producing fusion breeder consisting of a tandem mirror fusion device and two types of fission-suppressed blankets are presented. The majority of the study was devoted to the conceptual design and evaluation of the two blankets. However, studies in the areas of fusion engineering, reactor safety, fuel reprocessing, other fuel cycle issues, economics, and deployment were also performed

  13. Numerical simulation of large-scale MHD-mode stability in axisymmetric mirror systems

    International Nuclear Information System (INIS)

    Martynov, A.A.

    1989-01-01

    The formulation and the results of the numeric solution of a two-dimensional problem of anisotropic pressure plasma stability relative to large-scale MHD modes are presented for a system of traps consisting of a mirror device and an anchor-antimirror device. The extreme values β in the main trap depending on β in the ancor, mode number m on the position of the conducting wall. It is shown that in the case of high β the requirements of mode stability bring about considerably weaker (as compared with low-scale modes) limitations on pressure in the main trap

  14. Constraints on very-high-β, edge-stabilized tandem-mirror reactors

    Science.gov (United States)

    Potok, R. E.

    1985-08-01

    There are several tandem-mirror schemes which propose a very high β and edge stabilization for the center-cell plasma ( β being the ratio of the plasma pressure to the vacuum magnetic-field pressure). While the exact criteria for the edge stabilization are uncertain, it is possible to analyze the option space in which a very-high- β mirror reactor would operate. The primary physics constraints on such a reactor are the energy balance at ignition, the buildup of He4 ash and the hot α-particle β( β {α/hot}), and the need for adiabatic conservation of the hot α-particle gyro-orbits in the axial field gradients at the center-cell ends. There are also engineering constraints on the allowable wall loading and plant size. In this paper, a wall-stabilized tandem-mirror reactor is analyzed and is found to be an attractive device requiring low center-cell vacuum fields (of the order of 2 to 3 tesla). A primary requirement is that the plasma edge have a thermal conductivity near classical values.

  15. High field solenoids and cryogenic refrigeration system for the MFTF α + T tandem mirror facility

    International Nuclear Information System (INIS)

    Schultz, J.H.; Diatchenko, N.

    1984-01-01

    MFTF-α + T is a next step mirror device, specifically designed to be an upgrade of the MFTF-B tandem mirror facility into a generic nuclear testing facility for the magnetic fusion program. The solenoid magnet concepts, in particular an 18 T choke coil and a 12 T central cell coil, reflect the dependence of the tandem mirror concept on high performance, highly irradiated solenoids. The achievement of an 18 T solenoid with a 22 cm bore is a significant accomplishment in the total absence of radiation. The achievement of a normal magnet with a fluence of 4 x 10 12 rads of absorbed neutron and gamma radiation in its insulation is a significant achievement in the total absence of field. The achievement of a superconducting magnet with an instantaneous radiation absorption of 65 mW/cm 3 and an insulation fluence of 10 10 rads, let along a magnet with a peak field of nearly 16 T and a 107 cm bore is unprecedented. The superconducting and normal coils in the 18 T magnet system are also subjected to asymmetric axial loads from external magnets, adding the requirement of being able to support normal and fault loads in either axial direction. Nevertheless, it appears that design solutions do exist. The possible approaches to the simultaneous achievement of very high field, very high irradiation and asymmetric loading are the subject of this paper, using MFTF-α + T as the worked example

  16. Hot-electron plasma formation and confinement in the tandem mirror experiment-upgrade

    International Nuclear Information System (INIS)

    Ress, D.B.

    1988-06-01

    The tandem mirror experiment-upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is the first experiment to investigate the thermal-barrier tandem-mirror concept. One attractive feature of the tandem magnetic mirror as a commercial power reactor is that the fusion reactions occur in an easily accessible center-cell. On the other hand, complicated end-cells are necessary to provide magnetohydrodynamic (MHD) stability and improved particle confinement of the center-cell plasma. In these end-cells, enhanced confinement is achieved with a particular axial potential profile that is formed with electron-cyclotron range-of-frequency heating (ECRF heating, ECRH). By modifying the loss rates of electrons at spatially distinct locations within the end-cells, the ECRH can tailor the plasma potential profile in the desired fashion. Specifically, the thermal-barrier concept requires generation of a population of energetic electrons near the midplane of each end-cell. To be effective, the transverse (to the magnetic field) spatial structure of the hot-electron plasma must be fairly uniform. In this dissertation we characterize the spatial structure of the ECRH-generated plasma, and determine how the structure builds up in time. Furthermore, the plasma should efficiently absorb the ECRF power, and a large fraction of the electrons must be well confined near the end-cell midplane. Therefore, we also examine in detail the ECRH power balance, determining how the ECRF power is absorbed by the plasma, and the processes through which that power is confined and lost. 43 refs., 69 figs., 6 tabs

  17. Study of carbon ion behavior by using collisional radiative model in the GAMMA 10 tandem mirror

    International Nuclear Information System (INIS)

    Kobayashi, Takayuki; Yoshikawa, Masayuki; Kubota, Yuusuke; Saito, Masashi; Matama, Ken; Itakura, Akiyoshi; Cho, Teruji; Kato, Takako

    2006-01-01

    In a plasma experiment, collisional radiative model (CRM) is very useful model to evaluate impurity behaviors and plasma parameters with line emission from a plasma. CRMs for carbon and oxygen have been developed. However verification and application of the model for analysis of experimental results are not enough. Then we applied CRM calculation results to observed impurity spectra in the GAMMA 10 tandem mirror to evaluate the impurity density profile and the particle balance of each charge state of carbon ion. We calculated the effective ionization rate for each charge state of carbon ion and obtained the density profile of each ion. Moreover, we calculated absolute emission intensities from all carbon ions. (author)

  18. TMX tandem-mirror experiments and thermal-barrier theoretical studies

    International Nuclear Information System (INIS)

    Simonen, T.C.; Baldwin, D.E.; Allen, S.L.

    1982-01-01

    This paper describes recent analysis of energy confinement in the Tandem Mirror Experiment (TMX). TMX data also indicates that warm plasma limits the amplitude of the anisotropy driven Alfven ion cyclotron (AIC) mode. Theoretical calculations show strong AIC stabilization with off-normal beam injection as planned in TMX-U and MFTF-B. This paper reports results of theoretical analysis of hot electrons in thermal barriers including electron heating calculations by Monte Carlo and Fokker-Planck codes and analysis of hot electron MHD and microinstability. Initial results from the TMX-U experiment are presented which show the presence of sloshing ions

  19. Gyrotron scattering from non-thermal fluctuations in the Tara Tandem Mirror

    International Nuclear Information System (INIS)

    Machuzak, J.S.; Myer, R.C.; Woskoboinikow, P.P.

    1987-09-01

    A 137 GHz, ∼0.4 kW, 75 ms pulsed gyrotron has been used for collective Thomson scattering in the Tara Tandem Mirror plug cell at MIT. Scattering from ion cyclotron waves during ion cyclotron resonance frequency (ICRF) heating, ion Bernstein wave harmonics, and plasma fluctuations possibly due to microinstabilities have been observed. The observed harmonic nature of the ion Bernstein waves may be due to an enhanced ion thermal frequency spectrum in an ICRF heated plasma. 6 refs., 1 fig

  20. Effect of sheared flow on drift and Kelvin-Helmholtz instabilities in a tandem mirror

    International Nuclear Information System (INIS)

    Zhu, P.; Tsai, S.T.

    1996-01-01

    The effect of non-uniform rotation with a jet profile on the drift and Kelvin-Helmholtz instabilities in a tandem mirror is investigated numerically. Certain regimes of the flow parameters are found where the drift instability is nearly suppressed and the transverse Kelvin-Helmholtz instability is not induced. The growth rate of the Kelvin-Helmholtz instability can also be reduced to almost zero by a sufficiently large rotation frequency or by a radial electric field with moderate shear. The wave-flow resonant interaction may account for the stabilizing effect of sheared flow on drift and Kelvin-Helmholtz instabilities. (Author)

  1. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    International Nuclear Information System (INIS)

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future

  2. Initial results of the Tandem Mirror Experiment (TMX) at the Lawrence Livermore Laboratory

    International Nuclear Information System (INIS)

    Grubb, D.P.; Anderson, C.A.; Casper, T.A.; Clauser, J.F.; Coensgen, F.H.; Correll, D.L.; Cummins, W.F.; Davis, J.C.; Drake, R.P.; Foote, J.H.

    1980-01-01

    Initial experimental results from the Tandem Mirror Experiment (TMX) are presented. Axial profiles of the plasma density and potential necessary for electrostatically enhanced confinement of the central-cell ions have been generated and sustained for the duration of neutral-beam injection. The resulting central-cell ion confinement against axial loss is improved by a factor as large as 9 above that given by magnetic confinement alone. The plasma exhibits gross magnetohydrodynamic stability and microstability. Under some conditions, a residual level of ion cyclotron fluctuations in the end cells heats the central-cell ions and degrades their confinement

  3. Neutronics shielding analysis for the end plug of a tandem mirror fusion reactor

    Science.gov (United States)

    Ragheb, Magdi M. H.; Maynard, Charles W.

    1981-10-01

    A neutronics analysis using the Monte Carlo method is carried out for the end-plug penetration and magnet system of a tandem mirror fusion reactor. Detailed penetration and the magnets' three-dimensional configurations are modeled. A method of position dependent angular source biasing is developed to adequately sample the DT fusion source in the central cell region and obtain flux contributions at the penetration components. To assure cryogenic stability, the barrier cylindrical solenoid is identified as needing substantial shielding of about 1 m of a steel-lead-boron-carbide-water mixture. Heating rates there would require a thermal-hydraulic design similar to that in the central cell blanket region. The transition coils, however, need a minimal 0.2 m thickness shield. The leakage neutron flux at the direct converters is estimated at 1.3×1015 n/(m2·s), two orders of magnitude lower than that reported at the neutral beam injectors for tokamaks around 1017 n/(m2·s) for a 1 MW/m2 14 MeV neutron wall loading. This result is obtained through a coupling between the nuclear and plasma physics designs in which hydrogen ions rather than deuterium atoms are used for energy injection at the end plug, to avoid creating a neutron source there. This lower and controllable radiation leakage problem is perceived as a potential major advantage of tandem mirrors compared to tokamaks and laser reactor systems.

  4. Chemical engineering challenges in driving thermochemical hydrogen processes with the tandem mirror reactor

    International Nuclear Information System (INIS)

    Galloway, T.R.; Werner, R.W.

    1980-01-01

    The Tandem Mirror Reactor is described and compared with Tokamaks, both from a basic physics viewpoint and from the suitability of the respective reactor for synfuel production. Differences and similarities between the TMR as an electricity producer or a synfuel producer are also cited. The Thermochemical cycle chosen to link with the fusion energy source is the General Atomic Sulfur-Iodine Cycle, which is a purely thermal-driven process with no electrochemical steps. There are real chemical engineering challenges of getting this high quality heat into the large thermochemical plant in an efficient manner. We illustrate with some of our approaches to providing process heat via liquid sodium to drive a 1050 K, highly-endothermic, catalytic and fluidized-bed SO 3 Decomposition Reactor. The technical, economic, and safety tradeoffs that arise are discussed

  5. Commercial tandem mirror reactor design with thermal barriers: WITAMIR-I

    International Nuclear Information System (INIS)

    Kulcinski, G.L.; Emmert, G.A.; Maynard, C.W.

    1980-10-01

    A conceptual design of a near term commercial tandem mirror power reactor is presented. The basic configuration utilizes yin-yang minimum-B plugs with inboard thermal barriers. The maximum magnetic fields are 6.1 T, 8.1 T, and 15 T in the central cell, yin-yang, and thermal barrier magnets, respectively. The blanket utilizes Pb 83 Li 17 as the coolant and HT-9 as the structural material. This yields a high energy multiplication (1.37), a sufficient tritium breeding ratio (1.07) and has a major advantage with respect to maintenance. The plasma Q is 28 at a fusion power level of 3000 MW(t); the net electrical output is 1530 MW(e); and the overall efficiency is 39%. Cost estimates indicate that WITAMIR-I is competitive with recent tokamak power reactor designs

  6. Synfuels from fusion: producing hydrogen with the tandem mirror reactor and thermochemical cycles

    Energy Technology Data Exchange (ETDEWEB)

    Ribe, F.L.; Werner, R.W.

    1981-01-21

    This report examines, for technical merit, the combination of a fusion reactor driver and a thermochemical plant as a means for producing synthetic fuel in the basic form of hydrogen. We studied: (1) one reactor type - the Tandem Mirror Reactor - wishing to use to advantage its simple central cell geometry and its direct electrical output; (2) two reactor blanket module types - a liquid metal cauldron design and a flowing Li/sub 2/O solid microsphere pellet design so as to compare the technology, the thermal-hydraulics, neutronics and tritium control in a high-temperature operating mode (approx. 1200 K); (3) three thermochemical cycles - processes in which water is used as a feedstock along with a high-temperature heat source to produce H/sub 2/ and O/sub 2/.

  7. Synfuels from fusion: producing hydrogen with the tandem mirror reactor and thermochemical cycles

    International Nuclear Information System (INIS)

    Ribe, F.L.; Werner, R.W.

    1981-01-01

    This report examines, for technical merit, the combination of a fusion reactor driver and a thermochemical plant as a means for producing synthetic fuel in the basic form of hydrogen. We studied: (1) one reactor type - the Tandem Mirror Reactor - wishing to use to advantage its simple central cell geometry and its direct electrical output; (2) two reactor blanket module types - a liquid metal cauldron design and a flowing Li 2 O solid microsphere pellet design so as to compare the technology, the thermal-hydraulics, neutronics and tritium control in a high-temperature operating mode (approx. 1200 K); (3) three thermochemical cycles - processes in which water is used as a feedstock along with a high-temperature heat source to produce H 2 and O 2

  8. Special topics reports for the reference tandem mirror fusion breeder: beryllium lifetime assessment. Volume 3

    International Nuclear Information System (INIS)

    Miller, L.G.; Beeston, J.M.; Harris, B.L.; Wong, C.P.C.

    1984-10-01

    The lifetime of beryllium pebbles in the Reference Tandem Mirror Fusion Breeder blanket is estimated on the basis of the maximum stress generated in the pebbles. The forces due to stacking height, lithium flow, and the internal stresses due to thermal expansion and differential swelling are considered. The total stresses are calculated for three positions in the blanket, at a first wall neutron wall loading of 1.3 MW/m 2 . These positions are: (a) near the first fuel zone wall, (b) near the center, and (c) near the back wall. The average lifetime of the pebbles is estimated to be 6.5 years. The specific estimated lifetimes are 2.4 years, 5.4 years, and 15 years for the first fuel zone wall, center and near the back wall, respectively

  9. Configuring the thermochemical hydrogen sulfuric acid process step for the Tandem Mirror Reactor

    International Nuclear Information System (INIS)

    Galloway, T.R.

    1981-01-01

    This paper identifies the sulfuric acid step as the critical part of the thermochemical cycle in dictating the thermal demands and temperature requirements of the heat source. The General Atomic Sulfur-Iodine Cycle is coupled to a Tandem Mirror. The sulfuric acid decomposition process step is focused on specifically since this step can use the high efficiency electrical power of the direct converter together with the other thermal-produced electricity to Joule-heat a non-catalytic SO 3 decomposer to approximately 1250 0 K. This approach uses concepts originally suggested by Dick Werner and Oscar Krikorian. The blanket temperature can be lowered to about 900 0 K, greatly alleviating materials problems, the level of technology required, safety problems, and costs. A moderate degree of heat has been integrated to keep the cycle efficiency around 48%, but the number of heat exchangers has been limited in order to keep hydrogen production costs within reasonable bounds

  10. Review of the Tandem Mirror Experiment-Upgrade (TMX-U) machine-parameter-instrumentation system

    International Nuclear Information System (INIS)

    Kane, R.J.; Coffield, F.E.; Coutts, G.W.; Hornady, R.S.

    1983-01-01

    The Tandem Mirror Experiment-Upgrade (TMX-U) machine consists of seven major machine subsystems: magnet system, neutral beam system, microwave heating (ECRH), ion heating (ICRH), gas fueling, stream guns, and vacuum system. Satisfactory performance of these subsystems is necessary to achieve the experimental objectives planned for TMX-U operations. Since the performance quality of the subsystem is important and can greatly affect plasma parameters, a 233-channel instrumentation system has been installed. Data from the instrumentation system are acquired and stored with the plasma diagnostic information. Thus, the details of the machine performance are available during post-shot analysis. This paper describes all the machine-parameter-instrumentation hardware, presents some typical data, and outlines how the data are used

  11. Parametric cost analysis for tandem-mirror reactors similar to WITAMIR-I

    International Nuclear Information System (INIS)

    Montalvo, E.; Santarius, J.F.; Sviatoslavsky, I.N.

    1981-03-01

    The recently completed tandem mirror reactor study, WITAMIR-I, contains a detailed cost analysis at a reference point. Motivated by the existence of that analysis a model is developed to obtain the dependence of cost on the most important variables. Reactor parameters are varied using POWBAL, an equilibrium power balance code. Then, POWBAL output plus cost parameters are fed into the subroutine COST. The analysis is limited to configurations similar to WITAMIR-I, expanding costs about the reference point. This is a simplified model that allows for parametric studies without necessitating the detailed evaluation done for the reference design. It is useful in setting design parameters that minimize the cost of electricity as well as in analyzing the relative importance of the different parts of the plant

  12. Maintainability considerations for the central cell in WITAMIR-I, a conceptual design of a tandem mirror fusion power reactor

    International Nuclear Information System (INIS)

    Sviatoslavsky, I.N.

    1980-10-01

    The concepts for maintaining the central cell reactor components for WITAMIR-I are described. WITAMIR-I is a conceptual tandem mirror fusion power reactor utilizing thermal barriers designed by the University of Wisconsin-Madison. Unique solutions to the difficult problems of routine blanket replacement and maintenance are proposed. Solutions are also proposed for maintaining the central cell coils and the shield

  13. Utilizing subcooled, superfluid He-II in the design of a 12-Tesla tandem mirror experiment

    International Nuclear Information System (INIS)

    Hoard, R.W.; Cornish, D.N.; Baldi, R.W.; Taylor, W.D.

    1981-01-01

    A design study of 12-T yin-yang coils for a conceptual Tandem Mirror Next Step facility has been recently performed by Lawrence Livermore National Laboratory in conjunction with the Convair Division of General Dynamics. The large magnets have major and mirror radii of 3.7 and 1.5 m, 0.70 x 3.75 m 2 cross section, 46.3 MA turns, and an overall current density of 1765 A/cm 2 , obtained by the use of Nb 3 Sn and Nb-Ti superconductors. Each coil is composed of several subcoils separated by internal strengthening substructure to react the enormous electromagnetic forces. The size of the yin-yang coils, and hence the current density, was reduced by utilizing subcooled, superfluid He-II at 1.8 K for the coolant. This paper reviews the design study, with emphasis on He-II heat transport and conductor stability. Methods are also presented which allow the extension of Gorter-Mellink-channel calculations to encompass multiple, interconnecting coolant channels

  14. Development of divertor simulation research in the GAMMA 10/PDX tandem mirror

    International Nuclear Information System (INIS)

    Nakashima, Y.; Sakamoto, M.; Yoshikawa, M.; Oki, K.; Takeda, H.; Ichimura, K.; Hosoi, K.; Hirata, M.; Ichimura, M.; Ikezoe, R.; Imai, T.; Kariya, T.; Katanuma, I.; Kohagura, J.; Minami, R.; Numakura, T.; Wang, X.; Iwamoto, M.; Hosoda, Y.; Asakura, Nobuyuki; Fukumoto, Masakatsu; Kubo, Hirotaka; Hatayama, A.; Hirooka, Y.; Masuzaki, S.; Sagara, A.; Shoji, M.; Kado, S.; Matsuura, H.; Nagata, S.; Shikama, T.; Nishino, N.; Ohno, N.; Tonegawa, A.; Ueda, Y.

    2014-10-01

    This paper describes the recent development of divertor simulation research towards the characterization and control of the detached plasma. In the end-mirror of large tandem mirror device GAMMA 10/PDX, additional ICRF heating experiments in the anchor-cells significantly increases the density in both the anchor and the central cells, which attained the highest particle flux up to 1.7×10 23 particles/s·m 2 at the end-mirror exit. Massive gas injection (H 2 and noble gases) to enhance the radiation cooling in divertor simulation experimental module (D-module) was performed and we have succeeded for the first time in achieving detachment of high temperature plasma equivalent to the SOL plasma of tokamaks by using linear device. A remarkable reduction of the electron temperature (from few tens eV to < 3 eV) on the target plate was successfully achieved associated with the strong reduction of particle and heat fluxes. Two-dimensional image of Hα emission in D-module observed with high-speed camera showed the bright emission in upstream region and strong reduction near the target plate. These results indicate radiation cooling and formation of detached plasma due to gas injection. It is also found that Xe gas is much effective on achieving detached plasma than Ar gas. Simultaneous injection of noble gas and hydrogen gas showed the most effective results on detached plasma generation, which indicates the effect of molecular activated recombination (MAR) processes. The above results will contribute to establishment of detached plasma control and clarification of radiation cooling mechanism towards the development of future divertor systems. (author)

  15. Design of self-cooled, liquid-metal blankets for tokamak and tandem mirror reactors

    International Nuclear Information System (INIS)

    Cha, Y.S.; Gohar, Y.; Hassanein, A.M.; Majumdar, S.; Picologlou, B.F.; Smith, D.L.; Szo, D.K.

    1985-01-01

    Results of the self-cooled, liquid-metal blanket design from the Blanket Comparison and Selection Study (BCSS) are summarized. The objectives of the BCSS project are to define a small number (about three) of blanket concepts that should be the focus of the blanket research and development (RandD) program, identify and prioritize the critical issues for the leading blanket concepts, and provide technical input necessary to develop a blanket RandD program plan. Two liquid metals (lithium and lithium-lead (17Li-83Pb)) and three structural materials (primary candidate alloy (PCA), ferritic steel (FS) (HT-9), and vanadium alloy (V-15 Cr-5 Ti)) are included in the evaluations for both tokamaks and tandem mirror reactors (TMRs). TMR is of the tube configuration similar to the Mirror Advanced Reactor Study design. Analyses were performed in the following generic areas for each blanket concept: MHD, thermal hydraulics, stress, neutronics, and tritium recovery. Integral analyses were performed to determine the design window for each blanket design. The Li/Li/V blanket for tokamak and the Li/Li/V, LiPb/LiPb/V, and Li/Li/HT-9 blankets for the TMR are judged to be top-rated concepts. Because of its better thermophysical properties and more uniform nuclear heating profile, liquid lithium is a better coolant than liquid 17Li83Pb. From an engineering point of view, vanadium alloy is a better structural material than either FS or PCA since the former has both a higher allowable structural temperature and a higher allowable coolant/structure interface temperature than the latter. Critical feasibility issues and design constraints for the self-cooled, liquid-metal blanket concepts are identified and discussed

  16. START/TM: a study of start-up and fractional power operation of tandem mirror fusion reactors

    International Nuclear Information System (INIS)

    Conn, R.W.; Ghoniem, N.M.; Najmabadi, F.

    1984-01-01

    Start-up, shutdown and fractional power operation are important parts of power reactor operation. Special requirements for operation during these phases often place design constraints on key subsystems and can influence the fundamental design approach. This report presents investigations of these problems for tandem mirror fusion reactors (TMR's) and is referred to as the START/TM study. As a basis for the work, the MARS conceptual tandem mirror reactor design is used as the general reactor model. An overall framework is developed for start-up and fractional power increases to full power, applicable to any fusion reactor. Five phases are identified that include initial commissioning, cold or hot shutdown, system testing and plasma initiation to a standby mode, staged power increases, and rated power operation. Both general and specific constraints associated with these phases are identified and a plasma shutdown scenario is developed

  17. Mirroring

    DEFF Research Database (Denmark)

    Wegener, Charlotte; Wegener, Gregers

    2016-01-01

    and metaphorical value of mirroring for creativity theory across two different research fields — neuroscience and learning. We engage in a mutual (possibly creative) exploration of mirroring from ‘mirror neurons’ to mirroring in social learning theory. One of the most fascinating aspects of mirroring...... as a neurobiological and as a learning phenomenon is that it points to the embodied and unconscious aspects of social interaction. Thus, mirroring should not be reduced to the non-creative, mechanical repetition of the original, outstanding creativity. To mirror is a human capability built into our capacity to create...

  18. Spectroscopic analysis of low Z impurities in the Tandem Mirror Experiment-upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T.L.

    1986-09-01

    Two absolutely calibrated EUV instruments have been used to study the impurity characteristics in the Tandem Mirror Experiment-Upgrade (TMX-U). One instrument is a normal incidence spectrograph that measures the time histories of several impurity emission lines (300 to 1800 A) in a single shot; radial scans can be obtained on a shot-by-shot basis. The other instrument is a monochromator that measures time-resolved radial profiles of a given impurity emission line in a single shot. The common intrinsic impurities measured in TMX-U are C,N,O and Ti. It has been shown that large fractions of the oxygen and nitrogen in the plasma are associated with the neutral beams while the main source of carbon is the plasma wall. In general, the concentration of each of the impurities is low (<1%), and the power radiated by them is less than 10 kW, which is a small portion of the total input power to the plasma. The concentrations of the impurities can be reduced substantially blow discharge cleaning and titanium gettering. No significant accumulation of impurity ions in the thermal barrier region has been observed.

  19. Fusion reactor control study. Volume 3. Tandem mirror reactors. Final report

    International Nuclear Information System (INIS)

    Chang, F.R.; DeCanio, F.; Fisher, J.L.; Madden, P.A.

    1982-03-01

    A study of the control requirements of the Tandem Mirror Reactor concept is reported. The study describes the development of a control simulator that is based upon a spatially averaged physics code of the reactor concept. The simulator portrays the evolution of the plasma through the complete reactor operating cycle; it includes models of the control and measurement system, thus allowing the exploration of various strategies for reactor control. Startup, shutdown, and control during the quasi-steady-state power producing phase were explored. Configurations are described which use a variety of control effectors including modulation of the refueling rate, beam current, and electron cyclotron resonance heating. Multivariable design techniques were used to design the control laws and compensators for the feedback controllers and presume the practical measurement of only a subset of the plasma and machine variables. Performance of the various controllers is explored using the nonlinear control simulator. Derivative control strategies using new or developed sensors and effectors appropriate to a power reactor environment are postulated, based upon the results of the control configurations tested. Research and development requirements for these controls are delineated

  20. Thermal-hydraulics design comparisons for the tandem mirror hybrid reactor blanket

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Yang, Y.S.; Schultz, K.R.

    1980-09-01

    The Tandem Mirror Hybrid Reactor (TMHR) is a cylindrical reactor, and the fertile materials and tritium breeding fuel elements can be arranged with radial or axial orientation in the blanket module. Thermal-hydraulics performance comparisons were made between plate, axial rod and radial rod fuel geometrices. The three configurations result in different coolant/void fractions and different clad/structure fractions. The higher void fraction in the two rod designs means that these blankets will have to be thicker than the plate design blanket in order to achieve the same level of nuclear interactions. Their higher structural fractions will degrade the uranium breeding ratio and energy multiplication factor of the design. One difficulty in the thermal-hydraulics analysis of the plate design was caused by the varying energy multiplication of the blanket during the lifetime of the plate which forced the use of designs that operated in the transition flow regime at some point during life. To account for this, an approach was adopted from Gas Cooled Fast Reactor (GCFR) experience for the pressure drop calculation and the corresponding heat transfer coefficient that was used for the film drop thermal calculation. Because of the superior nuclear performance, the acceptable thermal-hydraulic characteristics and the mechanical design feasibility, the plate geometry concept was chosen for the reference gas-cooled TMHR blanket design

  1. Drift orbits in the TMX and MFTF-B tandem mirrors

    International Nuclear Information System (INIS)

    Byers, J.A.

    1982-01-01

    Drift orbits for the TMX and MFTF-B tandem-mirror designs are followed by using a long-thin expansion of the drift equations. Unexpected asymmetries in the field-line curvatures in the yin-yang end-mirror traps, caused by the transition coils between the solenoid and the yin-yang, result in an elliptical distortion of the drift surface with a/b=1.5 at most, a perhaps tolerable deviation from omnigenity. Yushmanov-trapped particles are no worse than the bulk hot particles. Finite-beta plasma fields, coupled to the asymmetric curvature, produce sizeable banana orbits with widths comparable to the plasma radius, but these orbits are possible for only a few of the particles. Details of the transition through resonance in the solenoid are shown, including the banana shapes of the drift surfaces and the disruption of the surface in the stochastic regime. The orbits in the original design for the A-cell of MFTF-B are the most extreme; in the vacuum fields they all have an extended peanut shape that finally closes only at about 3m. This shape is strongly non-omnigenous and suggests a hollow plasma-density profile. Finite-beta B vectorxnablaB drifts can help to minimize the radial extent of these orbits, but the strength of the vacuum curvatures makes omnigenity only marginally possible. Including B vectorxnablaphi drifts makes omnigenity even more unlikely for the ions, for which the B vectorxnablaB and B vectorxnablaphi drifts are of opposite sign, and conversely helps to omnigenize the drift surfaces of the ECRH 200-keV electrons. It is argued that not every class of particles can have good, i.e. near-omnigenous drifts, regardless of the ability of phi(r) to adjust to limit the radial extent of the orbits. This lack of omnigenity leaves one with no theoretical base for describing the MHD equilibrium in the original designs, but a new magnetic field design for MFTF-B A-cell has apparently completely restored omnigenous orbits. (author)

  2. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Falabella, S.

    1988-01-01

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10 12 cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs

  3. Thermal analysis of a helium-cooled, tube-bank blanket module for a tandem mirror fusion reactor

    International Nuclear Information System (INIS)

    Werner, R.W.

    1983-01-01

    A blanket module concept for the central cell of a tandem mirror reactor is described which takes advantage of the excellent heat transfer and low pressure drop characteristics of tube banks in cross-flow. The blanket employs solid Li 2 O as the tritium breeding material and helium as the coolant. The lithium oxide is contained in tubes arranged within the submodules as a two-pass, cross-flow heat exchanger. Primarily, the heat transfer and thermal-hydraulic aspects of the blanket design study are described in this paper. In particular, the analytical model used for selection of the best tube-bank design parameters is discussed in some detail

  4. Conceptual design study FY 1981: synfuels from fusion - using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Krikorian, O.H. (ed.)

    1982-02-09

    This report represents the second year's effort of a scoping and conceptual design study being conducted for the express purpose of evaluating the engineering potential of producing hydrogen by thermochemical cycles using a tandem mirror fusion driver. The hydrogen thus produced may then be used as a feedstock to produce fuels such as methane, methanol, or gasoline. The main objective of this second year's study has been to obtain some approximate cost figures for hydrogen production through a conceptual design study.

  5. TANDEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Tandem Van de Graaff facility provides researchers with beams of more than 40 different types of ions - atoms that have been stripped of their electrons. One of...

  6. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Conceptual design studies were made of fusion reactors based on the three current mirror-confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fuel for fission reactors. We have designed a large commercial hybrid and a small pilot-plant hybrid based on standard mirror confinement. Tandem mirror designs include a commercial 1000-MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single-cell pilot plant

  7. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Moir, R.W.

    1978-01-01

    We have carried out conceptual design studies of fusion reactors based on the three current mirror confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fission fuel for fission reactors. We have designed a large commercial hybrid based on standard mirror confinement, and also a small pilot plant hybrid. Tandem mirror designs include a commercial 1000 MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single cell pilot plant

  8. Behaviour of hot ions and spontaneously excited Alfven ion cyclotron mode in the GAMMA 10 tandem mirror

    International Nuclear Information System (INIS)

    Ichimura, Makoto; Tanaka, Satoru; Nakamura, Motoyuki

    2000-01-01

    With a strong ion cyclotron range of frequency (ICRF) heating in the GAMMA 10 tandem mirror, an ion temperature of 10 keV has been attained and a temperature anisotropy has been observed to become greater than 10. Unstable Alfven ion cyclotron (AIC) modes are driven with such a strong temperature anisotropy. High energy ions with energies of more than 50 keV are detected both parallel and perpendicular to the magnetic field lines. With the AIC modes, increase of the high energy ions at the end of the device and decrease of the high energy ions with a pitch angle of nearly 90 degrees are observed. The pitch angle scattering of high energy ions due to the spontaneously excited Alfven modes in the plasma is suggested. (author)

  9. Fusion plasma theory Task II: ECRH and transport modeling in tandem mirrors and divertor physics. Final report, January 1-December 31, 1985

    International Nuclear Information System (INIS)

    Emmert, G.A.

    1985-07-01

    The research reported here focuses on: (1) the coupling of an ECRH ray tracing and absorption code to a tandem mirror transport code in order to self-consistently model the temporal and spatial evolution of the plasma, and (2) the further development of semi-analytical models for plasma flow in divertors and pumped limiters. 5 refs., 1 fig

  10. Plasma characteristics of the end-cell of the GAMMA 10 tandem mirror for the divertor simulation experiment

    International Nuclear Information System (INIS)

    Nakashima, Y.; Sakamoto, M.; Yoshikawa, M.; Takeda, H.; Ichimura, K.; Hosoi, K.; Hirata, M.; Ichimura, M.; Ikezoe, R.; Imai, T.; Kariya, T.; Katanuma, I.; Kohagura, J.; Minami, R.; Numakura, T.; Oki, K.; Ueda, H.; Asakura, Nobuyuki; Furuta, T.; Hatayama, A.; Toma, M.; Hirooka, Y.; Masuzaki, S.; Sagara, A.; Shoji, M.; Kado, S.; Matsuura, H.; Nagata, S.; Nishino, N.; Ohno, N.; Tonegawa, A.; Ueda, Y.

    2012-11-01

    In this paper, detailed characteristics and controllability of plasmas emitted from the end-cell of the GAMMA 10 tandem mirror are described from the viewpoint of divertor simulation studies. The energy analysis of ion flux by using end-loss ion energy analyzer (ELIEA) proved that the obtained high ion temperature (100 - 400 eV) was comparable to SOL plasma parameters in toroidal devices and was controlled by changing the ICRF power. Parallel ion temperature T i∥ determined from the probe and calorimeter shows a linear relationship with the ICRF power in the central-cell and agrees with the results of ELIEA. Additional ICRF heating revealed a significant enhancement of particle flux, which indicated an effectiveness of additional plasma heating in adjacent cells toward the improvement of the performance. Superimposing the ECH pulse of 380 kW, 5 ms attained the maximum heat-flux more than 10 MW/m 2 on axis. This value comes up to the heat-load of the divertor plate of ITER, which gives a clear prospect of generating the required heat density for divertor studies by building up heating systems to the end-mirror cell. Initial results of plasma irradiation experiment and construction of new divertor module are also described. (author)

  11. Tandem Mirror Experiment-Upgrade neutral beam test stand: A powerful tool for development and quality assurance

    International Nuclear Information System (INIS)

    Hibbs, S.M.; Kane, R.J.; Kerr, R.G.; Poulsen, P.

    1983-01-01

    During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), a test stand was assembled to develop electronics for the neutral beam system. In the first six months of test stand use the authors operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, the focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance and development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises the final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U. They have also used the test stand to perform a series of physics experiments, including: reducing gas flow through valve and arc chamber characterization, reducing impurities by titanium gettering, and reducing streaming gas using apertures and collisional gas dynamics

  12. Design and fabrication of circular and rectangular components for electron-cyclotron-resonant heating of tandem mirror experiment-upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Felker, B.; Calderon, M.O.; Chargin, A.K.; Coffield, F.E.; Lang, D.D.; Rubert, R.R.; Pedrotti, L.R.; Stallard, B.W.; Gallagher, N.C. Jr.; Sweeney, D.W.

    1983-11-18

    The electron-cyclotron-resonant heating (ECRH) systems of rectangular waveguides on Tandem Mirror Experiment-Upgrade (TMX-U) operated with a overall efficiency of 50%, each system using a 28-GHz, 200-kW pulsed gyrotron. We designed and built four circular-waveguide systems with greater efficiency and greater power-handling capabilities to replace the rectangular waveguides. Two of these circular systems, at the 5-kG second-harmonic heating locations, have a total transmission efficiency of >90%. The two systems at the 10-kG fundamental heating locations have a total transmission efficiency of 80%. The difference in efficiency is due to the additional components required to launch the microwaves in the desired orientation and polarization with respect to magnetic-field lines at the 10-kG points. These systems handle the total power available from each gyrotron but do not have the arcing limitation problem of the rectangular waveguide. Each system requires several complex components. The overall physical layout and the design considerations for the rectangular and circular waveguide components are described here.

  13. Design and fabrication of circular and rectangular components for electron-cyclotron-resonant heating of tandem mirror experiment-upgrade

    International Nuclear Information System (INIS)

    Felker, B.; Calderon, M.O.; Chargin, A.K.

    1983-01-01

    The electron-cyclotron-resonant heating (ECRH) systems of rectangular waveguides on Tandem Mirror Experiment-Upgrade (TMX-U) operated with a overall efficiency of 50%, each system using a 28-GHz, 200-kW pulsed gyrotron. We designed and built four circular-waveguide systems with greater efficiency and greater power-handling capabilities to replace the rectangular waveguides. Two of these circular systems, at the 5-kG second-harmonic heating locations, have a total transmission efficiency of >90%. The two systems at the 10-kG fundamental heating locations have a total transmission efficiency of 80%. The difference in efficiency is due to the additional components required to launch the microwaves in the desired orientation and polarization with respect to magnetic-field lines at the 10-kG points. These systems handle the total power available from each gyrotron but do not have the arcing limitation problem of the rectangular waveguide. Each system requires several complex components. The overall physical layout and the design considerations for the rectangular and circular waveguide components are described here

  14. Tandem mirror experiment-upgrade neutral beam test stand: a powerful tool for development and quality assurance

    International Nuclear Information System (INIS)

    Hibbs, S.M.; Kane, R.J.; Kerr, R.G.; Poulsen, P.

    1983-01-01

    During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), we assembled a test stand to develop electronics for the neutral beam system. In the first six months of test stand use we operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, our focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance andd development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises our final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U

  15. Task II: ECRH and transport modeling in tandem mirrors and divertor physics. Annual progress report on fusion plasma theory, January 1, 1983-December 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Emmert, G.A.

    1983-08-01

    The research performed under Task II of this contract has focused on (1) the coupling of an ECRH ray tracing and absorption code to a tandem mirror transport code in order to self-consistently model the temporal and spatial evolution of the plasma, and (2) the further development of a semi-analytical kinetic model for plasma flow in divertors and pumped limiters. Work on these topics is briefly summarized in this progress report.

  16. Investigation of auxiliary heating in tandem mirrors and tokamaks and barrier cell pumping. Annual progress report, October 1, 1980 to December 31, 1981

    International Nuclear Information System (INIS)

    Emmert, G.A.; Scharer, J.

    1981-06-01

    The research has focussed on physics questions concerned with ECRH heating in tandem mirror plugs, pumping of tandem mirror thermal barriers by drift orbits, ICRH heating in tokamaks, and bundle divertors. We have concluded that drift-orbit pumping of thermal barriers is not feasible because the azimuthal E Vector X B Vector drift limits the excursion of trapped ions from a flux surface. We have developed a three-dimensional weakly relativistic (T/sub e/ less than or equal to 50 keV) ray tracing and absorption code for electron cyclotron heating in tandem mirror plugs and barriers. Cases run for TMX, MFTF-B and reactors at T/sub e/ > 10 keV show that strong absorption per pass is present and a careful choice of wave frequency and launch angle is required to ensure wave penetration and absorption in the plasma core. In the area of ion cyclotron frequency range heating in tokamaks, a three-dimensional hot plasma ray tracing theory and code has been developed to handle rays launched from any poloidal angle in the tokamak cross section. Wave heating in the central strong absorption zones is currently being investigated using a full wave solution for the various heating regimes

  17. Active optics and the axisymmetric case: MINITRUST wide-field three-reflection telescopes with mirrors aspherized from tulip and vase forms

    Science.gov (United States)

    Lemaitre, Gerard R.; Montiel, Pierre; Joulie, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2004-09-01

    Wide-field astronomy requires larger size telescopes. Compared to the catadioptric Schmidt, the optical properties of a three mirror telescope provides significant advantages. (1) The flat field design is anastigmatic at any wavelength, (2) the system is extremely compact -- four times shorter than a Schmidt -- and, (3) compared to a Schmidt with refractive corrector -- requiring the polishing of three optical surfaces --, the presently proposed Modified-Rumsey design uses all of eight available free parameters of a flat fielded anastigmatic three mirror telescope for mirrors generated by active optics methods. Compared to a Rumsey design, these parameters include the additional slope continuity condition at the primary-tertiary link for in-situ stressing and aspherization from a common sphere. Then, active optics allows the polishing of only two spherical surfaces: the combined primary-tertiary mirror and the secondary mirror. All mirrors are spheroids of the hyperboloid type. This compact system is of interest for space and ground-based astronomy and allows to built larger wide-field telescopes such as demonstrated by the design and construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° FOV, consisting of an in-situ stressed double vase form primary-tertiary and of a stress polished tulip form secondary. Optical tests of these telescopes, showing diffraction limited images, are presented.

  18. Computer control of the titanium getter system on the tandem mirror experiment-upgrade (TMX-U)

    International Nuclear Information System (INIS)

    McAlice, A.J.; Bork, R.G.; Clower, C.A.; Moore, T.L.; Lang, D.D.; Pico, R.E.

    1983-01-01

    Gettering has been a standard technique for achieving high-quality vacuum in fusion experiments for some time. On Lawrence Livermore National Laboratory's Tandem Mirror Experiment (TMX-U), an extensive gettering system is utilized with liquid-nitrogen-cooled panels to provide the fast pumping during each physics experiment. The getter wires are a 85% titanium and 15% tantalum alloy directly heated by an electrical current. TMX-U has 162 getter power-supply channels; each channel supplies approximately 106 A of regulated power to each getter for a 60-s cycle. In the vacuum vessel, the getter wires are organized into poles or arrays. On each pole there are six getter wires, each cables to the exterior of the vessel. This arrangement allows the power supplies to be switched from getter wire to getter wire as the individual wires deteriorate after 200 to 300 gettering cycles. To control the getter power suppiles, we will install a computer system to operate the system and document the performance of each getter circuit. This computer system will control the 162 power supplies via a Computer Automated Measurement and Control (CAMAC) architecture with a fiber-optic serial highway. Getter wire history will be stored on the built-in 10 megabyte disc drive with new entries backed up daily on a floppy disc. Overall, this system will allow positive tracking of getter wire condition, document the total gettering performance, and predict getter maintenance/changeover cycles. How we will employ the computer system to enhance the getter system is the subject of this paper

  19. Tandem mirror theory workshop

    International Nuclear Information System (INIS)

    1981-05-01

    The workshop was divided into three sections which were constituted according to subject matter: RF Heating, MHD Equilibrium and Stability, and Transport and Microstability. An overview from Livermore's point of view was given at the beginning of each session. Each session was assigned a secretary to take notes. These notes have been used in preparing this report on the workshop. The report includes the activities, conclusions, and recommendations of the workshop

  20. Measurement of effect of electron cyclotron heating in a tandem mirror plasma using a semiconductor detector array and an electrostatic energy analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Minami, R., E-mail: minami@prc.tsukuba.ac.jp; Imai, T.; Kariya, T.; Numakura, T.; Uehara, M.; Tsumura, K.; Ebashi, Y.; Kajino, S.; Endo, Y.; Nakashima, Y. [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2016-11-15

    Temporally and spatially resolved soft x-ray and end-loss-electron analyses of the electron cyclotron heated plasmas are carried out by using a semiconductor detector array and an electrostatic energy analyzer in the GAMMA 10 tandem mirror. The flux and the energy spectrum of the end loss electrons are measured by a multi-grid energy analyzer. Recently, the electron cyclotron heating power modulation experiments have been started in order to generate and control the high heat flux and to make the edge localized mode-like intermittent heat load pattern for the divertor simulation studies by the use of these detectors for electron properties.

  1. Special topics reports for the reference tandem mirror fusion breeder: liquid metal MHD pressure drop effects in the packed bed blanket. Vol. 1

    International Nuclear Information System (INIS)

    McCarville, T.J.; Berwald, D.H.; Wong, C.P.C.

    1984-09-01

    Magnetohydrodynamic (MHD) effects which result from the use of liquid metal coolants in magnetic fusion reactors include the modification of flow profiles (including the suppression of turbulence) and increases in the primary loop pressure drop and the hydrostatic pressure at the first wall of the blanket. In the reference fission-suppressed tandem mirror fusion breeder design concept, flow profile modification is a relatively minor concern, but the MHD pressure drop in flowing the liquid lithium coolant through an annular packed bed of beryllium/thorium pebbles is directly related to the required first wall structure thickness. As such, it is a major concern which directly impacts fissile breeding efficiency. Consequently, an improved model for the packed bed pressure drop has been developed. By considering spacial averages of electric fields, currents, and fluid flow velocities the general equations have been reduced to simple expressions for the pressure drop. The averaging approach results in expressions for the pressure drop involving a constant which reflects details of the flow around the pebbles. Such details are difficult to assess analytically, and the constant may eventually have to be evaluated by experiment. However, an energy approach has been used in this study to bound the possible values of the constant, and thus the pressure drop. In anticipation that an experimental facility might be established to evaluate the undetermined constant as well as to address other uncertainties, a survey of existing facilities is presented

  2. Design scoping study of the 12T Yin-Yang magnet system for the Tandem Mirror Next Step (TMNS). Final report

    International Nuclear Information System (INIS)

    1981-09-01

    The overall objective of this engineering study was to determine the feasibility of designing a Yin-Yang magnet capable of producing a peak field in the windings of 12T for the Tandem Mirror Next Step (TMNS) program. As part of this technical study, a rough order of magnitude (ROM) cost estimate of the winding for this magnet was undertaken. The preferred approach to the winding design of the TMNS plug coil utilizes innovative design concepts to meet the structural, electrical and thermodynamic requirements of the magnet system. Structurally, the coil is radially partitioned into four sections, preventing the accumulation of the radial loads and reacting them into the structural case. To safely dissipate the 13.34 GJ of energy stored in each Yin-Yang magnet, the winding has been electrically subdivided into parallel or nested coils, each having its own power supply and protection circuitry. This arrangement effectively divides the total stored energy of the coils into manageable subsystems. The windings are cooled with superfluid helium II, operated at 1.8K and 1.2 atmospheres. The superior cooling capabilities of helium II have enabled the overall winding envelope to be minimized, providing a current density of 2367 A/CM 2 , excluding substructure

  3. Primary loop conditioning and design constraints of Li-Pb cooled tandem mirror reactors during start-up/shutdown operations

    International Nuclear Information System (INIS)

    Taghavi, K.; Ghoniem, N.M.

    1984-01-01

    Engineering considerations during start-up/shutdown operations, and during transients induced by power level variations are considered in this paper. Flooding of cold blanket modules with hot Li-Pb results in severe strain transients that may lead to fatigue failure. The entire primary system, including blanket modules, must therefore be pre-conditoned. We first analyze, and present results of design, for a pre-heat system for the Mirror Advanced Reactor Study (MARS). The pre-heat system is based on helium gas pre-heating for the primary piping and blanket modules. Operational transients induced by partial power variations, or by loss of fusion power are then considered. It is found that the response of the primary loop system is dictated by how fast pumps can accommodate power fluctuations. Pump transients are modeled with a focus on the time dependent power balance through the pump system. Time constants for a representative pump are also derived. Finally, the situation of a total loss of pump power is investigated. In this case, natural circulation due to boyancy pressure differences is shown to be sufficient for the removal of decay afterheat immediately after a loss of pump power. (orig.)

  4. Development of 1 MW gyrotron and progress of ECH system for the GAMMA 10 tandem mirror in Tsukuba

    International Nuclear Information System (INIS)

    Imai, T.; Kariya, T.; Minami, R.; Shidara, H.; Endo, Y.; Harigae, M.; Nakamura, M.; Sakagoshi, Y.; Murofushi, N.; Ichimura, M.; Nakashima, Y.; Yoshikawa, M.; Yamaguchi, Y.; Sakamoto, Keishi; Kubo, S.; Shimozuma, T.; Mutoh, T.; Takahashi, H.; Mitsunaka, Y.

    2008-10-01

    High power gyrotrons with TE 4,2 cavity at 28 GHz and with TE 18,6 cavity and a diamond window at 77 GHz have been developed for GAMMA 10 and LHD in the joint program of NIFS and University of Tsukuba. The maximum outputs of 570 kW at 28 GHz and 1.1 MW at 77 GHz were obtained corresponding to each design. The operations of more than 750 kW for 5 sec. and 810 kW for 3.5 sec. were achieved in the developing tubes at 77 GHz, which is the first high power-long pulse result of the 77 GHz tube. The experimental simulation of the effect of the stray RF in the 28 GHz tube indicates the stray RF is the one of the major causes limiting gyrotron performance. The output of more than 1 MW with 40% oscillation efficiency is expected from the design of the next 28 GHz gyrotron for GAMMA 10. Installation of the polarizer in the transmission line enhanced the performance of the ECH system in GAMMA 10, that is the first result which clearly showed ∼100% X mode excitation is a key to design the efficient fundamental ECH system of strong field side injection in mirror devices. (author)

  5. Thermal optical effect in axisymmetric structural laser resonator

    Science.gov (United States)

    Xu, Yonggen; Li, Yude

    2012-02-01

    In order to study the thermal optical effect (TOE) resulting from the axisymmetrical sources of thermal energy at the output mirror of CO 2 laser, the Heat Conduction Poisson Equation (HCPE) has been solved in the output mirror. Then the temperature distribution is given. The temperature variations will cause the surface distortion and the phase shift at the output mirror. Therefore, the output laser beam will be subject to thermal optical distortion and phase change. The numerical examples are to confirm our calculated results.

  6. Mirror plasma apparatus

    International Nuclear Information System (INIS)

    Moir, R.W.

    1981-01-01

    A mirror plasma apparatus which utilizes shielding by arc discharge to form a blanket plasma and lithium walls to reduce neutron damage to the wall of the apparatus. An embodiment involves a rotating liquid lithium blanket for a tandem mirror plasma apparatus wherein the first wall of the central mirror cell is made of liquid lithium which is spun with angular velocity great enough to keep the liquid lithium against the first material wall, a blanket plasma preventing the lithium vapor from contaminating the plasma

  7. Progress in mirror machine research

    International Nuclear Information System (INIS)

    Fowler, T.K.; Coensgen, F.H.

    1979-01-01

    The Mirror Fusion Program in the US is now focused on two concepts that can obtain high values of the power gain factor Q. These are the tandem mirror and field reversed mirror concepts. A new facility called TMX has been constructed to test the principles of the tandem mirror. A further attempt to create field reversal is being carried out in the 2XIIB facility (renamed Beta II) with neutral beam injection into a reversed-field target plasma to be created by a magnetized coaxial gun. During the next 5 years, the main mirror facilities in the US will be the TMX, Beta II, and a large mirror device called MFTF scheduled to operate by 1982. The program based on these facilities will be outlined and initial experimental results from TMX will be discussed

  8. Physics of mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1982-05-01

    In recent years the emphasis in research on the magnetic mirror approach to fusion has been shifted to address what are essentially economically-motivated issues. The introduction of the Tandem Mirror idea solved in principal the problem of low Q (low fusion power gain) of mirror-based fusion systems. In order to optimize the tandem mirror idea from an economic standpoint, some important improvements have been suggested. These improvements include the thermal barrier idea of Baldwin and Logan and the axicell concept of Kesner. These new modifications introduce some special physics considerations. Among these are (1) The MHD stability properties of high energy electron components in the end cells; (2) The optimization of end-cell magnetic field configurations with the objective of minimizing equilibrium parallel currents; (3) The suppression of microstabilities by use of sloshing ion distributions. Following a brief outline of tandem mirror concepts, the above three topics are discussed, with illustrative examples taken from earlier work or from recent design studies

  9. Remote servicing features of two new mirror fusion reactors

    International Nuclear Information System (INIS)

    Neef, W.S. Jr.

    1977-01-01

    Several general approaches to remote servicing are briefly described for the LLL Field Reversed Mirror and Tandem Mirror Fusion reactors. Remote servicing system design considerations for the blanket module are briefly discussed

  10. Axisymmetric control in tokamaks

    International Nuclear Information System (INIS)

    Humphreys, D.A.

    1991-02-01

    Vertically elongated tokamak plasmas are intrinsically susceptible to vertical axisymmetric instabilities as a result of the quadrupole field which must be applied to produce the elongation. The present work analyzes the axisymmetric control necessary to stabilize elongated equilibria, with special application to the Alcator C-MOD tokamak. A rigid current-conserving filamentary plasma model is applied to Alcator C-MOD stability analysis, and limitations of the model are addressed. A more physically accurate nonrigid plasma model is developed using a perturbed equilibrium approach to estimate linearized plasma response to conductor current variations. This model includes novel flux conservation and vacuum vessel stabilization effects. It is found that the nonrigid model predicts significantly higher growth rates than predicted by the rigid model applied to the same equilibria. The nonrigid model is then applied to active control system design. Multivariable pole placement techniques are used to determine performance optimized control laws. Formalisms are developed for implementing and improving nominal feedback laws using the C-MOD digital-analog hybrid control system architecture. A proportional-derivative output observer which does not require solution of the nonlinear Ricatti equation is developed to help accomplish this implementation. The nonrigid flux conserving perturbed equilibrium plasma model indicates that equilibria with separatrix elongation of at least κ sep = 1.85 can be stabilized robustly with the present control architecture and conductor/sensor configuration

  11. Fokker-Planck equation in mirror research

    International Nuclear Information System (INIS)

    Post, R.F.

    1983-01-01

    Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror

  12. Virtual Mirrors

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2010-01-01

    The multiple-reflection photograph in Fig. 1 was taken in an elevator on board the cruise ship Norwegian Jade in March 2008. Three of the four walls of the elevator were mirrored, allowing me to see the combination of two standard arrangements of plane mirrors: two mirrors set at 90 degrees to each other and two parallel mirrors. Optical phenomena…

  13. Modeling axisymmetric flow and transport

    Science.gov (United States)

    Langevin, C.D.

    2008-01-01

    Unmodified versions of common computer programs such as MODFLOW, MT3DMS, and SEAWAT that use Cartesian geometry can accurately simulate axially symmetric ground water flow and solute transport. Axisymmetric flow and transport are simulated by adjusting several input parameters to account for the increase in flow area with radial distance from the injection or extraction well. Logarithmic weighting of interblock transmissivity, a standard option in MODFLOW, can be used for axisymmetric models to represent the linear change in hydraulic conductance within a single finite-difference cell. Results from three test problems (ground water extraction, an aquifer push-pull test, and upconing of saline water into an extraction well) show good agreement with analytical solutions or with results from other numerical models designed specifically to simulate the axisymmetric geometry. Axisymmetric models are not commonly used but can offer an efficient alternative to full three-dimensional models, provided the assumption of axial symmetry can be justified. For the upconing problem, the axisymmetric model was more than 1000 times faster than an equivalent three-dimensional model. Computational gains with the axisymmetric models may be useful for quickly determining appropriate levels of grid resolution for three-dimensional models and for estimating aquifer parameters from field tests.

  14. Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Jorgenson, Roy Eberhardt

    2014-10-01

    This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank

  15. Evolution of the mirror approach to fusion: some conjectures

    International Nuclear Information System (INIS)

    Post, R.E.

    1984-01-01

    Some possible directions for the future evolution of the mirror approach to fusion are outlined, in the context of economically-motivated criteria. Speculations are given as to the potential advantages, economic and otherwise, of the use of axially-symmetric systems, operated in semi-collisional regimes of lower Q (fusion power balance ratio) than that projected for present-day tandem mirror designs. These regims include barely tandem modes, and ion-heated modes, in association with higher efficiency direct conversion. Another possible economically advantageous approach mentioned is the use of a tandem mirror plasma to stabilize a FRM (field-reversed mirror) plasma, with potential synergistic advantages

  16. Steps toward increasing Q in mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1979-01-01

    Experiments such as the 2XIIB experiment at Livermore have established the ability of mirror systems to confine high temperature, high density plasmas at central beta values exceeding unity. Given these results the next tasks for the mirror approach are to explore means for increasing the energy gain factor Q and to scale up the plasma volume, both of these requirements deriving from economic constraints. This report discusses means for increasng Q, including recent improvements in the tandem mirror concept and design studies of the field-reversed mirror in the context of upcoming and proposed scaled-up mirror experiments

  17. LLL mirror fusion program: summary

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1977-01-01

    During 1976, new Mirror Program plans have been laid out to take into account the significant advances during the last 18 months. The program is now focused on two new mirror concepts, field reversal and the tandem mirror, that can obtain high Q, defined as the ratio of fusion power output to the neutral-beam power injected to sustain the reaction. Theoretically, both concepts can attain Q = 5 or more, as compared to Q = 1 in previous mirror designs. Experimental planning for the next 5 years is complete in broad outline, and we are turning attention to what additional steps are necessary to reach our long-range goal of an experimental mirror reactor operating by 1990. Highlights of the events that have led to the above circumstance are listed, and experimental program plans are outlined

  18. Einstein's Mirror

    Science.gov (United States)

    Gjurchinovski, Aleksandar; Skeparovski, Aleksandar

    2008-01-01

    Reflection of light from a plane mirror in uniform rectilinear motion is a century-old problem, intimately related to the foundations of special relativity. The problem was first investigated by Einstein in his famous 1905 paper by using the Lorentz transformations to switch from the mirror's rest frame to the frame where the mirror moves at a…

  19. Axisymmetric finite deformation membrane problems

    Energy Technology Data Exchange (ETDEWEB)

    Feng, W.W.

    1980-12-12

    Many biomechanic problems involve the analysis of finite deformation axisymmetric membranes. This paper presents the general formulation for solving a class of axisymmetric membrane problems. The material nonlinearity, as well as the geometric nonlinearity, is considered. Two methods are presented to solve these problems. The first method is solving a set of differential equilibrium equations. The governing equations are reduced to three first-order ordinary-differential equations with explicit derivatives. The second method is the Ritz method where a general potential energy functional valid for all axisymmetric deformed positions is presented. The geometric admissible functions that govern the deformed configuration are written in terms of a series with unknown coefficients. These unknown coefficients are determined by the minimum potential energy principle that of all geometric admissible deformed configurations, the equilibrium configuration minimizes the potential energy. Some examples are presented. A comparison between these two methods is mentioned.

  20. Modern magnetic mirrors and their fusion prospects

    International Nuclear Information System (INIS)

    Burdakov, A V; Ivanov, A A; Kruglyakov, E P

    2010-01-01

    This paper reviews the most important findings from recent experiments on modern magnetic mirrors, apart from tandem mirrors and rotating plasma devices. These modern magnetic mirrors are represented by a multiple mirror device GOL-3 and a gas dynamic trap, experiments on which are carried out in Novosibirsk. Both devices are characterized by axial symmetry and improved axial confinement of plasma compared with conventional mirror machines. Recent findings from experiments enable us to more practically consider applications of the gas dynamic trap as a high-flux 14 MeV neutron source for fusion materials testing, and possibly as a driver for fusion-fission hybrids. They also indicate that effective axial plasma confinement in a multiple mirror can be obtained with a smaller plasma density compared with theory and β < 1. This is beneficial from the point of view of the technical realization of a multiple mirror reactor.

  1. Modern magnetic mirrors and their fusion prospects

    Science.gov (United States)

    Burdakov, A. V.; Ivanov, A. A.; Kruglyakov, E. P.

    2010-12-01

    This paper reviews the most important findings from recent experiments on modern magnetic mirrors, apart from tandem mirrors and rotating plasma devices. These modern magnetic mirrors are represented by a multiple mirror device GOL-3 and a gas dynamic trap, experiments on which are carried out in Novosibirsk. Both devices are characterized by axial symmetry and improved axial confinement of plasma compared with conventional mirror machines. Recent findings from experiments enable us to more practically consider applications of the gas dynamic trap as a high-flux 14 MeV neutron source for fusion materials testing, and possibly as a driver for fusion-fission hybrids. They also indicate that effective axial plasma confinement in a multiple mirror can be obtained with a smaller plasma density compared with theory and β < 1. This is beneficial from the point of view of the technical realization of a multiple mirror reactor.

  2. Phaedrus tandem mirror. Status report, Spring 1983

    International Nuclear Information System (INIS)

    1983-01-01

    During the spring of 1983, the Phaedrus group undertook a major up to air to improve diagnostic capabilities, modify RF antennas and clean up the inner vacuum surfaces of accumulated getter material. This time was also used to analyze more thoroughly our present data base and correlate it with relevant theoretical predictions. A neutral beam build up code has been developed to model RF central stream trapping and heating, neutral gas charge exchange losses with finite gyroradius effects, and beam aiming sensitivity. MHD stability of the central cell stand alone operation has been explained by a radial ponderomotive force which opposes the centrifugal force due to bad field line curvature. First drafts of research papers on RF trapping, electron cyclotron heating, the stand alone mode, and MHD instability studies were completed. All of these papers require more experiments to tie up loose ends but the loose ends were identified more clearly by this process. The remainder of this report will be organized by experimental area, describing in limited detail the status of current research, recent modifications to diagnostic and machine hardware and immediate future experimental objectives

  3. Magic Mirrors

    Science.gov (United States)

    Mills, Allan

    2011-01-01

    "Magic mirrors" were so named because, when they were positioned to throw a reflected patch of sunlight on a nearby wall, this area contained an outline of a design cast on the back of the (bronze) mirror. Investigations begun in the 19th century showed that this was a response to heavy localized pressures exerted on the face of the thin mirror…

  4. Seismic analysis of axisymmetric shells

    International Nuclear Information System (INIS)

    Jospin, R.J.; Toledo, E.M.; Feijoo, R.A.

    1984-01-01

    Axisymmetric shells subjected to multiple support excitation are studied. The shells are spatialy discretized by the finite element method and in order to obtain estimates for the maximum values of displacements and stresses the response spectrum tecnique is used. Finally, some numerical results are presented and discussed in the case of a shell of revolution with vertical symmetry axis, subjected to seismic ground motions in the horizontal, vertical and rocking directions. (Author) [pt

  5. On the axisymmetric Lewis metric

    International Nuclear Information System (INIS)

    Gariel, J.; Marcilhacy, G.

    2001-03-01

    We obtain the general solution of the axisymmetric stationary vacuum spacetime of Lewis. After precising the fundamental hypothesis of Lewis, we demonstrate that the solution is related to an arbitrary harmonic function. Formally, these solutions are the same as for the corresponding cylindrically symmetric case, and can be classified in a similar way. Furthermore, the interpretation, in the cylindrically symmetric system, of the field equations as decribing the motion of a classical particle in a central force field is still valid. (author)

  6. Einstein's Mirror

    Science.gov (United States)

    Gjurchinovski, Aleksandar; Skeparovski, Aleksandar

    2008-10-01

    Reflection of light from a plane mirror in uniform rectilinear motion is a century-old problem, intimately related to the foundations of special relativity.1-4 The problem was first investigated by Einstein in his famous 1905 paper by using the Lorentz transformations to switch from the mirror's rest frame to the frame where the mirror moves at a constant velocity.5 Einstein showed an intriguing fact that the usual law of reflection would not hold in the case of a uniformly moving mirror, that is, the angles of incidence and reflection of the light would not equal each other. Later on, it has been shown that the law of reflection at a moving mirror can be obtained in various alternative ways,6-10 but none of them seems suitable for bringing this interesting subject into the high school classroom.

  7. Mirror symmetry

    CERN Document Server

    Voisin, Claire

    1999-01-01

    This is the English translation of Professor Voisin's book reflecting the discovery of the mirror symmetry phenomenon. The first chapter is devoted to the geometry of Calabi-Yau manifolds, and the second describes, as motivation, the ideas from quantum field theory that led to the discovery of mirror symmetry. The other chapters deal with more specialized aspects of the subject: the work of Candelas, de la Ossa, Greene, and Parkes, based on the fact that under the mirror symmetry hypothesis, the variation of Hodge structure of a Calabi-Yau threefold determines the Gromov-Witten invariants of its mirror; Batyrev's construction, which exhibits the mirror symmetry phenomenon between hypersurfaces of toric Fano varieties, after a combinatorial classification of the latter; the mathematical construction of the Gromov-Witten potential, and the proof of its crucial property (that it satisfies the WDVV equation), which makes it possible to construct a flat connection underlying a variation of Hodge structure in the ...

  8. Mirror Advanced Reactor Study (MARS)

    International Nuclear Information System (INIS)

    Logan, B.G.

    1983-01-01

    Progress in a two year study of a 1200 MWe commercial tandem mirror reactor (MARS - Mirror Advanced Reactor Study) has reached the point where major reactor system technologies are identified. New design features of the magnets, blankets, plug heating systems and direct converter are described. With the innovation of radial drift pumping to maintain low plug density, reactor recirculating power fraction is reduced to 20%. Dominance of radial ion and impurity losses into the halo permits gridless, circular direct converters to be dramatically reduced in size. Comparisons of MARS with the Starfire tokamak design are made

  9. Magnetic mirror fusion: status and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Post, R.F.

    1980-02-11

    Two improved mirror systems, the tandem mirror (TM) and the field-reversed mirror (FRM) are being intensively studied. The twin practical aims of these studies: to improve the economic prospects for mirror fusion power plants and to reduce the size and/or complexity of such plants relative to earlier approaches to magnetic fusion. While at the present time the program emphasis is still strongly oriented toward answering scientific questions, the emphasis is shifting as the data accumulates and as larger facilities - ones with a heavy technological and engineering orientation - are being prepared. The experimental and theoretical progress that led to the new look in mirror fusion research is briefly reviewed, the new TM and the FRM ideas are outlined, and the projected future course of mirror fusion research is discussed.

  10. Magnetic mirror fusion: status and prospects

    International Nuclear Information System (INIS)

    Post, R.F.

    1980-01-01

    Two improved mirror systems, the tandem mirror (TM) and the field-reversed mirror (FRM) are being intensively studied. The twin practical aims of these studies: to improve the economic prospects for mirror fusion power plants and to reduce the size and/or complexity of such plants relative to earlier approaches to magnetic fusion. While at the present time the program emphasis is still strongly oriented toward answering scientific questions, the emphasis is shifting as the data accumulates and as larger facilities - ones with a heavy technological and engineering orientation - are being prepared. The experimental and theoretical progress that led to the new look in mirror fusion research is briefly reviewed, the new TM and the FRM ideas are outlined, and the projected future course of mirror fusion research is discussed

  11. Mirror Fusion Test Facility magnet system

    International Nuclear Information System (INIS)

    VanSant, J.H.; Kozman, T.A.; Bulmer, R.H.; Ng, D.S.

    1981-01-01

    In 1979, R.H. Bulmer of Lawrence Livermore National Laboratory (LLNL) discussed a proposed tandem-mirror magnet system for the Mirror Fusion Test Facility (MFTF) at the 8th symposium on Engineering Problems in Fusion Research. Since then, Congress has voted funds for expanding LLNL's MFTF to a tandem-mirror facility (designated MFTF-B). The new facility, scheduled for completion by 1985, will seek to achieve two goals: (1) Energy break-even capability (Q or the ratio of fusion energy to plasma heating energy = 1) of mirror fusion, (2) Engineering feasibility of reactor-scale machines. Briefly stated, 22 superconducting magnets contained in a 11-m-diam by 65-m-long vacuum vessel will confine a fusion plasma fueled by 80 axial streaming-plasma guns and over 40 radial neutral beams. We have already completed a preliminary design of this magnet system

  12. Mirror Advanced Reactor Study interim design report

    International Nuclear Information System (INIS)

    1983-04-01

    The status of the design of a tenth-of-a-kind commercial tandem-mirror fusion reactor is described at the midpoint of a two-year study. When completed, the design is to serve as a strategic goal for the mirror fusion program. The main objectives of the Mirror Advanced Reactor Study (MARS) are: (1) to design an attractive tandem-mirror fusion reactor producing electricity and synfuels (in alternate versions), (2) to identify key development and technology needs, and (3) to exploit the potential of fusion for safety, low activation, and simple disposal of radioactive waste. In the first year we have emphasized physics and engineering of the central cell and physics of the end cell. Design optimization and trade studies are continuing, and we expect additional modifications in the end cells to further improve the performance of the final design

  13. Mirror Advanced Reactor Study interim design report

    Energy Technology Data Exchange (ETDEWEB)

    1983-04-01

    The status of the design of a tenth-of-a-kind commercial tandem-mirror fusion reactor is described at the midpoint of a two-year study. When completed, the design is to serve as a strategic goal for the mirror fusion program. The main objectives of the Mirror Advanced Reactor Study (MARS) are: (1) to design an attractive tandem-mirror fusion reactor producing electricity and synfuels (in alternate versions), (2) to identify key development and technology needs, and (3) to exploit the potential of fusion for safety, low activation, and simple disposal of radioactive waste. In the first year we have emphasized physics and engineering of the central cell and physics of the end cell. Design optimization and trade studies are continuing, and we expect additional modifications in the end cells to further improve the performance of the final design.

  14. TASKA - Tandem Spiegelmaschine Karlsruhe. Vol. 1

    International Nuclear Information System (INIS)

    1982-06-01

    TASKA (Tandem Spiegelmaschine Karlsruhe) is a near term engineering test facility based on a tandem mirror concept with thermal barriers. The main objectives of this study were to develop a preconceptual design of a facility that could provide engineering design information for a Demonstration Fusion Power Reactor. Thus TASKA has to serve as testbed for technologies of plasma engineering, superconducting magnets, materials, plasma heating, breeding and test blankets, tritium technology, and remote handling. (orig.) [de

  15. Anomalous transport in mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1979-01-01

    As now being explored for fusion applications confinement systems based on the mirror principle embody two kinds of plasma regimes. These two regimes are: (a) high-beta plasmas, stabilized against MHD and other low frequency plasma instabilities by magnetic-well fields, but characterized by non-Maxwellian ion distributions; (b) near-Maxwellian plasmas, confined electrostatically (as in the tandem mirror) or in a field-reversed region within the mirror cell. Common to both situations are the questions of anomalous transport owing to high frequency instabilities in the non-maxwellian portions of the plasmas. This report will summarize the status of theory and of experimental data bearing on these questions, with particular reference to the high temperature regimes of interest for fusion power

  16. Mirror, mirror on the wall

    CERN Multimedia

    2005-01-01

    RICH 2, one of the two Ring Imaging Cherenkov detectors of the LHCb experiment, is being prepared to join the other detector elements ready for the first proton-proton collisions at LHC. The mirrors of the RICH2 detector are meticulously assembled in a clean room.In a large dark room, men in white move around an immense structure some 7 metres high, 10 metres wide and nearly 2.5 metres deep. Apparently effortlessly, they are installing the two large high-precision spherical mirrors. These mirrors will focus Cherenkov light, created by the charged particles that will traverse this detector, onto the photon detectors. Each spherical mirror wall is made up of facets like a fly's eye. Twenty-eight individual thin glass mirrors will all point to the same point in space to within a few micro-radians. The development of these mirrors has been technically demanding : Ideally they should be massless, sturdy, precise and have high reflectivity. In practice, though not massless, they are made from a mere 6 mm thin gl...

  17. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  18. Axisymmetric Marangoni convection in microencapsulation

    Science.gov (United States)

    Subramanian, Pravin; Zebib, Abdelfattah; McQuillan, Barry

    2005-07-01

    Spherical shells used as laser targets in inertial confinement fusion (ICF) experiments are made by microencapsulation. In one phase of manufacturing, the spherical shells contain a solvent (fluorobenzene (FB)) and a solute (polystyrene (PAMS)) in a water-FB environment. Evaporation of the FB results in the desired hardened plastic hollow spherical shells, 1-2 mm in diameter. Perfect sphericity is demanded for efficient fusion ignition and the observed surface roughness maybe driven by Marangoni instabilities due to surface tension dependence on the FB concentration (buoyant forces are negligible in this micro-scale problem). Here we model this drying process and compute nonlinear, time-dependent, axisymmetric, variable viscosity, infinite Schmidt number solutocapillary convection in the shells. Comparison with results from linear theory and available experiments are made.

  19. Streamline topology of axisymmetric flows

    DEFF Research Database (Denmark)

    Brøns, Morten

    Topological fluid mechanics in the sense of the present paper is the study and classification of flow patterns close to a critical point. Here we discuss the topology of steady viscous incompressible axisymmetric flows in the vicinity of the axis. Following previous studies the velocity field $v...... to the authors knowledge has not been used systematically to high orders in topological fluid mechanics. We compare the general results with experimental and computational results on the Vogel-Ronneberg flow. We show that the topology changes observed when recirculating bubbles on the vortex axis are created...... and interact follow the topological classification and that the complete set of patterns found is contained in a codimension-4 unfolding of the most simple singular configuration....

  20. CRUCIB: an axisymmetric convection code

    International Nuclear Information System (INIS)

    Bertram, L.A.

    1975-03-01

    The CRUCIB code was written in support of an experimental program aimed at measurement of thermal diffusivities of refractory liquids. Precise values of diffusivity are necessary to realistic analysis of reactor safety problems, nuclear waste disposal procedures, and fundamental metal forming processes. The code calculates the axisymmetric transient convective motions produced in a right circular cylindrical crucible, which is surface heated by an annular heat pulse. Emphasis of this report is placed on the input-output options of the CRUCIB code, which are tailored to assess the importance of the convective heat transfer in determining the surface temperature distribution. Use is limited to Prandtl numbers less than unity; larger values can be accommodated by replacement of a single block of the code, if desired. (U.S.)

  1. Conicoid Mirrors

    Science.gov (United States)

    Castano, Diego J.; Hawkins, Lawrence C.

    2011-01-01

    The first-order equation relating object and image location for a mirror of arbitrary conic-sectional shape is derived. It is also shown that the parabolic reflecting surface is the only one free of aberration and only in the limiting case of distant sources. (Contains 3 figures.)

  2. Mirror Support

    Science.gov (United States)

    Baron, Richard L. (Inventor)

    2013-01-01

    Disclosed herein is a method of making a mirror support comprising a composite, the composite comprising a plurality of carbon nanotubes, wherein at least two of the plurality of carbon nanotubes are bonded to each other through a bridging moiety bound to each of the two carbon nanotubes, and a laminate comprising the composite.

  3. New Classes of Quasi-Axisymmetric Configurations

    International Nuclear Information System (INIS)

    Ku, L. P.; Garabedian, P. R.

    2005-01-01

    Stellarators with quasi-axially symmetric (QA) magnetic field structure have attracted considerable interests in recent years. They are expected to have good particle orbits found in tokamaks and may be made passively stable to MHD perturbations found in conventional stellarators. A proof-of-principle device, the National Compact Stellarator Experiment (NCSX), is being designed and operation is expected to begin in 2008 [1]. In parallel, a reactor studies project (ARIES-CS) is being conducted to examine critical issues of compact stellarators as power producing reactors [2]. It is under the auspices of this project that we made an extensive survey of the aspect ratio-rotational transform space to look for regions endowed with particularly interesting characteristics. We report in this paper the progress made in identifying new configurations with unique features of different emphasis that may be of interest from the standpoint of both power producing reactors and near term physics experiments. NCSX is a highly optimized configuration in both physics and coil properties. The baseline plasma was chosen for its low aspect ratio (A equal 4.5), low non-axisymmetric residues in the magnetic spectrum (<2.5%) and good MHD stability characteristics. The coils were designed with sufficient room to accommodate the scrape-off, vacuum vessel, diagnostics, etc., and with enough flexibility to accommodate a wide variety of operating scenarios. However, the configuration space is vast and complex. Possibilities exist that there are other configurations also having good properties. To look beyond NCSX, we asked ourselves: are there other configurations more attractive and what additional properties will make a quasi-axisymmetric stellarator (QAS) more attractive? We note that recent experimental results from W7AS and LHD showed that, while magnetohydrodynamic (MHD) activities apparently existed in these devices, the plasmas nevertheless were quiescent and remained quasi

  4. What do mirror neurons mirror?

    NARCIS (Netherlands)

    Uithol, S.; Rooij, I.J.E.I. van; Bekkering, H.; Haselager, W.F.G.

    2011-01-01

    Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data

  5. Adaptative mixed methods to axisymmetric shells

    International Nuclear Information System (INIS)

    Malta, S.M.C.; Loula, A.F.D.; Garcia, E.L.M.

    1989-09-01

    The mixed Petrov-Galerkin method is applied to axisymmetric shells with uniform and non uniform meshes. Numerical experiments with a cylindrical shell showed a significant improvement in convergence and accuracy with adaptive meshes. (A.C.A.S.) [pt

  6. Mirror systems

    International Nuclear Information System (INIS)

    Howells, M.R.

    1985-12-01

    The physics of VUV and x-ray reflection is reviewed. The main functions of mirrors in synchrotron beamlines are stated briefly and include deflection, filtration, power absorption, formation of a real image of the source, focusing, and collimation. Methods of fabrication of optical surfaces are described. Types of imperfections are discussed, including, aberrations, surface figure inaccuracy, roughness, and degradation due to use. Calculation of the photon beam thermal load, including computer modelling, is considered. 50 refs., 7 figs

  7. Hydrodynamic Stability Analysis of the Externally Excited Axisymmetric Mode in Reacting, Swirling Jets

    Science.gov (United States)

    Emerson, Benjamin; Lieuwen, Tim

    2017-11-01

    This study investigates the forced response characteristics of axisymmetric structures in density-stratified swirling jets. The reacting, swirling jet is an important canonical flow field for modern combustion systems. This work is motivated by the combustion instability problem for such systems, where acoustically excited vortical structures may drive oscillatory heat release of combustion. Previous hydrodynamics studies have shown that the stability of helical structures is highly sensitive to the swirl number. However, the combustion literature has shown that axisymmetric structures (in contrast to helical structures) are often responsible for most of the heat release response. Therefore, this work performs a spatial stability analysis to study the swirl number sensitivity of the forced response of the axisymmetric mode. A spatio-temporal analysis is conducted in tandem to investigate the swirl number sensitivity of the impulse response of this mode. The results show that at low values of the swirl number, the axisymmetric mode stability is a weak function of the swirl number, but that new modes and stability bifurcations appear at high swirl numbers.

  8. Supersonic quasi-axisymmetric vortex breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1991-01-01

    An extensive computational study of supersonic quasi-axisymmetric vortex breakdown in a configured circular duct is presented. The unsteady, compressible, full Navier-Stokes (NS) equations are used. The NS equations are solved for the quasi-axisymmetric flows using an implicit, upwind, flux difference splitting, finite volume scheme. The quasi-axisymmetric solutions are time accurate and are obtained by forcing the components of the flowfield vector to be equal on two axial planes, which are in close proximity of each other. The effect of Reynolds number, for laminar flows, on the evolution and persistence of vortex breakdown, is studied. Finally, the effect of swirl ration at the duct inlet is investigated.

  9. Novel neutron focusing mirrors for compact neutron sources

    Science.gov (United States)

    Khaykovich, B.; Gubarev, M. V.; Zavlin, V. E.; Katz, R.; Resta, G.; Liu, D.; Robertson, L.; Crow, L.; Ramsey, B. D.; Moncton, D. E.

    We demonstrated neutron beam focusing and neutron imaging using axisymmetric optics, based on pairs of confocal ellipsoid and hyperboloid mirrors. Such systems, known as Wolter mirrors, are commonly used in x-ray telescopes. A system containing four nested Ni mirror pairs was implemented and tested by focusing a polychromatic neutron beam at the MIT Reactor and conducting an imaging experiment at HFIR. The major advantage of the Wolter mirrors is the possibility of nesting for large angular collection. Using nesting, the relatively short optics can be made comparable to focusing guides in flux collection capabilities. We discuss how such optics can be used as polychromatic lenses to improve the performance of small-angle-scattering, imaging, and other instruments at compact neutron sources.

  10. Stability of stationary-axisymmetric black holes in vacuum general relativity to axisymmetric electromagnetic perturbations

    Science.gov (United States)

    Prabhu, Kartik; Wald, Robert M.

    2018-01-01

    We consider arbitrary stationary and axisymmetric black holes in general relativity in (d +1) dimensions (with d ≥slant 3 ) that satisfy the vacuum Einstein equation and have a non-degenerate horizon. We prove that the canonical energy of axisymmetric electromagnetic perturbations is positive definite. This establishes that all vacuum black holes are stable to axisymmetric electromagnetic perturbations. Our results also hold for asymptotically de Sitter black holes that satisfy the vacuum Einstein equation with a positive cosmological constant. Our results also apply to extremal black holes provided that the initial perturbation vanishes in a neighborhood of the horizon.

  11. The spectrum of axisymmetric torsional Alfven waves

    International Nuclear Information System (INIS)

    Sy, W.N.

    1977-03-01

    The spectrum of axisymmetric torsional Alfven waves propagating in a cylindrical, non-uniform, resistive plasma waveguide has been analysed by a method of singular perturbations. A simple condition has been derived which predicts whether the spectrum is continuous or discrete under given physical conditions. Application of this result to resolve an apparent discrepancy in experimental observations is briefly discussed. (Author)

  12. Mirror Fusion Test Facility: an intermediate device to a mirror fusion reactor

    International Nuclear Information System (INIS)

    Karpenko, V.N.

    1983-01-01

    The Mirror Fusion Test Facility (MFTF-B) now under construction at Lawrence Livermore National Laboratory represents more than an order-of-magnitude step from earlier magnetic-mirror experiments toward a future mirror fusion reactor. In fact, when the device begins operating in 1986, the Lawson criteria of ntau = 10 14 cm -3 .s will almost be achieved for D-T equivalent operation, thus signifying scientific breakeven. Major steps have been taken to develop MFTF-B technologies for tandem mirrors. Steady-state, high-field, superconducting magnets at reactor-revelant scales are used in the machine. The 30-s beam pulses, ECRH, and ICRH will also introduce steady-state technologies in those systems

  13. Standard mirror fusion reactor design study

    International Nuclear Information System (INIS)

    Moir, R.W.

    1978-01-01

    This report covers the work of the Magnetic Fusion Energy Division's reactor study group during FY 1976 on the standard mirror reactor. The ''standard'' mirror reactor is characterized as a steady state, neutral beam sustained, D-T fusioning plasma confined by a Yin-Yang magnetic mirror field. The physics parameters are obtained from the same physics model that explains the 2XIIB experiment. The model assumes that the drift cyclotron loss cone mode occurs on the boundary of the plasma, and that it is stabilized by warm plasma with negligible energy investment. The result of the study was a workable mirror fusion power plant, steady-state blanket removal made relatively simple by open-ended geometry, and no impurity problem due to the positive plasma potential. The Q (fusion power/injected beam power) turns out to be only 1.1 because of loss out the ends from Coulomb collisions, i.e., classical losses. This low Q resulted in 77% of the gross electrical power being used to power the injectors, thereby causing the net power cost to be high. The low Q stimulated an intensive search for Q-enhancement concepts, resulting in the LLL reactor design effort turning to the field reversal mirror and the tandem mirror, each having Q of order 5

  14. Axisymmetric instability in a noncircular tokamak

    International Nuclear Information System (INIS)

    Lipschultz, B.

    1979-10-01

    The stability of dee, inverse-dee and square cross section plasmas to axisymmetric modes has been investigated experimentally in Tokapole II, a tokamak with a four-null poloidal divertor. Experimental results are closely compared with predictions of two numerical stability codes - the PEST code (ideal MHD, linear stability) adapted to tokapole geometry and a code which follows the nonlinear evolution of shapes similar to tokapole equilibria

  15. Axisymmetric ideal magnetohydrodynamic equilibria with incompressible flows

    International Nuclear Information System (INIS)

    Tasso, H.; Throumoulopoulos, G.N.

    1997-12-01

    It is shown that the ideal MHD equilibrium states of an axisymmetric plasma with incompressible flows are governed by an elliptic partial differential equation for the poloidal magnetic flux function ψ containing five surface quantities along with a relation for the pressure. Exact equilibria are constructed including those with non vanishing poloidal and toroidal flows and differentially varying radial electric fields. Unlike the case in cylindrical incompressible equilibria with isothermal magnetic surfaces which should have necessarily circular cross sections [G. N. Throumoulopoulos and H. Tasso, Phys. Plasmas 4, 1492 (1997)], no restriction appears on the shapes of the magnetic surfaces in the corresponding axisymmetric equilibria. The latter equilibria satisfy a set of six ordinary differential equations which for flows parallel to the magnetic field B can be solved semianalytically. In addition, it is proved the non existence of incompressible axisymmetric equilibria with (a) purely poloidal flows and (b) non-parallel flows with isothermal magnetic surfaces and vertical stroke B vertical stroke = vertical stroke B vertical stroke (ψ) (omnigenous equilibria). (orig.)

  16. Recent Progress in Mirror Studies in Novosibirsk

    International Nuclear Information System (INIS)

    Kruglyakov, E.P.; Dimov, G.I.; Ivanov, A.A.; Koidan, V.S.

    2005-01-01

    At present, in the Budker Institute of Nuclear Physics there is in operation the most complete set of modern mirror machines based on different principles of plasma confinement. This set includes the multi-mirror system GOL-3 for confinement of dense plasma heated by relativistic electron beam, the gas dynamic trap (GDT) for confinement of collisional plasma and anisotropic fast ions, and the ambipolar trap AMBAL-M.Mirrors have a number of advantages in comparison with the closed magnetic systems like tokamak, stellarator, etc. The most important are the following. The effects of disruptions are not appeared in mirrors. There are no divertor problems in them. Plasma pressure in a mirror device can be comparable with magnetic field pressure. As to the multi-mirror system, in this case, the β value can be even significantly higher than unity (the so called >). At last, mirrors are convenient for direct conversion of energy of charged particles leaving out the ends. This circumstance can turn out to be especially important in future > schemes of fusion reactors.In principle, mirrors are very attractive from the engineering point of view, if the plasma confined in axisymmetric magnetic systems would be MHD stable. At present, the problem of MHD stability has already been solved for all axisymmetric traps designed in Novosibirsk. At least, the value β [approximately or equal to] 0.4 was obtained in these traps without any indications of macroscopic instability development.Some important results were obtained recently in the GOL-3 experiments. A specific mechanism of reduction of longitudinal electron thermal conductivity was detected. Recently, the magnetic system of the GOL-3 device was reconstructed into multi-mirror configuration. In this configuration, a new mechanism of fast ion heating was observed. As a result, the ion temperature was increased from a few eV up to 1 keV and the confinement time significantly increased (up to 1ms). These results were obtained

  17. Mirror Neurons and Mirror-Touch Synesthesia.

    Science.gov (United States)

    Linkovski, Omer; Katzin, Naama; Salti, Moti

    2016-05-30

    Since mirror neurons were introduced to the neuroscientific community more than 20 years ago, they have become an elegant and intuitive account for different cognitive mechanisms (e.g., empathy, goal understanding) and conditions (e.g., autism spectrum disorders). Recently, mirror neurons were suggested to be the mechanism underlying a specific type of synesthesia. Mirror-touch synesthesia is a phenomenon in which individuals experience somatosensory sensations when seeing someone else being touched. Appealing as it is, careful delineation is required when applying this mechanism. Using the mirror-touch synesthesia case, we put forward theoretical and methodological issues that should be addressed before relying on the mirror-neurons account. © The Author(s) 2016.

  18. Durable solar mirror films

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.; Katare, Rajesh K.; Jing, Naiyong; North, Diane; Peterson, Eric M.

    2017-02-14

    The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

  19. Low Cost Method of Manufacturing Cooled Axisymmetric Scramjets, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Scramjet engine developers are working on advanced axisymmetric engine concepts that may not be feasible due to limitations of currently available manufacturing...

  20. Mirror machine reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Moir, R.W.

    1976-01-01

    Recent mirror reactor conceptual design studies are described. Considered in detail is the design of ''standard'' Yin-Yang fusion power reactors with classical and enhanced confinement. It is shown that to be economically competitive with estimates for other future energy sources, mirror reactors require a considerable increase in Q, or major design simplifications, or preferably both. These improvements may require a departure from the ''standard'' configuration. Two attractive possibilities, both of which would use much of the same physics and technology as the ''standard'' mirror, are the field reversed mirror and the end-stoppered mirror

  1. 3D equilibrium codes for mirror machines

    International Nuclear Information System (INIS)

    Kaiser, T.B.

    1983-01-01

    The codes developed for cumputing three-dimensional guiding center equilibria for quadrupole tandem mirrors are discussed. TEBASCO (Tandem equilibrium and ballooning stability code) is a code developed at LLNL that uses a further expansion of the paraxial equilibrium equation in powers of β (plasma pressure/magnetic pressure). It has been used to guide the design of the TMX-U and MFTF-B experiments at Livermore. Its principal weakness is its perturbative nature, which renders its validity for high-β calculation open to question. In order to compute high-β equilibria, the reduced MHD technique that has been proven useful for determining toroidal equilibria was adapted to the tandem mirror geometry. In this approach, the paraxial expansion of the MHD equations yields a set of coupled nonlinear equations of motion valid for arbitrary β, that are solved as an initial-value problem. Two particular formulations have been implemented in computer codes developed at NYU/Kyoto U and LLNL. They differ primarily in the type of grid, the location of the lateral boundary and the damping techniques employed, and in the method of calculating pressure-balance equilibrium. Discussions on these codes are presented in this paper. (Kato, T.)

  2. Numerical determination of axisymmetric toroidal magnetohydrodynamic equilibria

    International Nuclear Information System (INIS)

    Johnson, J.L.; Dalhed, H.E.; Greene, J.M.

    1978-07-01

    Numerical schemes for the determination of stationary axisymmetric toroidal equilibria appropriate for modeling real experimental devices are given. Iterative schemes are used to solve the elliptic nonlinear partial differential equation for the poloidal flux function psi. The principal emphasis is on solving the free boundary (plasma-vacuum interface) equilibrium problem where external current-carrying toroidal coils support the plasma column, but fixed boundary (e.g., conducting shell) cases are also included. The toroidal current distribution is given by specifying the pressure and either the poloidal current or the safety factor profiles as functions of psi. Examples of the application of the codes to tokamak design at PPPL are given

  3. Reversed straining in axisymmetric compression test

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Wanheim, Tarras; Lindegren, Maria

    2005-01-01

    A large group of the cold forging processes is carried out in a thick – walled container with the deformation force transmitted through a punch moving axially in the container. The work piece, being entrapped between punch and container will expand and exert a radial pressure resulting in an expa...... to simulate these conditions a reversed axisymmetrical material tester is designed and constructed. Three different materials were tested, aluminum alloy AA6082, technically pure copper (99.5%) and cold forging steel Ma8, at different temperatures found during cold forging....

  4. An axisymmetric inertia-gravity wave generator

    Science.gov (United States)

    Maurer, P.; Ghaemsaidi, S. J.; Joubaud, S.; Peacock, T.; Odier, P.

    2017-10-01

    There has been a rich interplay between laboratory experimental studies of internal waves and advancing understanding of their role in the ocean and atmosphere. In this study, we present and demonstrate the concept for a new form of laboratory internal wave generator that can excite axisymmetric wave fields of arbitrary radial structure. The construction and operation of the generator are detailed, and its capabilities are demonstrated through a pair of experiments using a Bessel function and a bourrelet (i.e., ring-shaped) configuration. The results of the experiments are compared with the predictions of an accompanying analytical model.

  5. Quantitative shearography in axisymmetric gas temperature measurements

    Science.gov (United States)

    VanDerWege, Brad A.; O'Brien, Christopher J.; Hochgreb, Simone

    1999-06-01

    This paper describes the use of shearing interferometry (shearography) for the quantitative measurement of gas temperatures in axisymmetric systems in which vibration and shock are substantial, and measurement time is limited. The setup and principle of operation of the interferometer are described, as well as Fourier-transform-based fringe pattern analysis, Abel transform, and sensitivity of the phase lead to temperature calculation. A helium jet and a Bunsen burner flame are shown as verification of the diagnostic. The accuracy of the measured temperature profile is shown to be limited by the Abel transform and is critically dependent on the reference temperature used.

  6. Topological fluid mechanics of Axisymmetric Flow

    DEFF Research Database (Denmark)

    Brøns, Morten

    1998-01-01

    Topological fluid mechanics in the sense of the present paper is the study and classification of flow patterns close to a critical point. Here we discuss the topology of steady viscous incompressible axisymmetric flows in the vicinity of the axis. Following previous studies the velocity field v...... to the authors knowledge has not been used systematically to high orders in topological fluid mechanics. We compare the general results with experimental and computational results on the Vogel-Ronneberg flow. We show that the topology changes observed when recirculating bubbles on the vortex axis are created...

  7. The TESS [Tandem Experiment Simulation Studies] computer code user's manual

    International Nuclear Information System (INIS)

    Procassini, R.J.

    1990-01-01

    TESS (Tandem Experiment Simulation Studies) is a one-dimensional, bounded particle-in-cell (PIC) simulation code designed to investigate the confinement and transport of plasma in a magnetic mirror device, including tandem mirror configurations. Mirror plasmas may be modeled in a system which includes an applied magnetic field and/or a self-consistent or applied electrostatic potential. The PIC code TESS is similar to the PIC code DIPSI (Direct Implicit Plasma Surface Interactions) which is designed to study plasma transport to and interaction with a solid surface. The codes TESS and DIPSI are direct descendants of the PIC code ES1 that was created by A. B. Langdon. This document provides the user with a brief description of the methods used in the code and a tutorial on the use of the code. 10 refs., 2 tabs

  8. Axisymmetric vibrations of thick shells of revolution

    International Nuclear Information System (INIS)

    Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin

    1983-01-01

    Axisymmetric shells of revolution are used for chemical plants, nuclear power plants, aircrafts, structures and so on, and the elucidation of their free vibration is important for the design. In this study, the axisymmetric vibration of a barrel-shaped shell was analyzed by the modified thick shell theory. The Lagrangian during one period of the vibration of a shell of revolution was determined, and from its stopping condition, the vibration equations and the boundary conditions were derived. The vibration equations were analyzed strictly by using the series solution. Moreover, the basic equations for the strain of a shell and others were based on those of Love. As the examples of numerical calculation, the natural frequency and vibration mode of the symmetrical shells of revolution fixed at both ends and supported at both ends were determined, and their characteristics were clarified. By comparing the results of this study with the results by thin shell theory, the effects of shearing deformation and rotary inertia on the natural frequency and vibration mode were clarified. The theoretical analysis and the numerical calculation are described. The effects of shearing deformation and rotary inertia on the natural frequency became larger in the higher order vibration. The vibration mode did not much change in both theories. (Kako, I.)

  9. Near surface stress analysis strategies for axisymmetric fretting

    Indian Academy of Sciences (India)

    In this paper, we develop design tools for Near Surface Analysis (NSA) for understanding axisymmetric fretting. Axisymmetric Fretting Analysis (AFA) becomes formidable owing to localised tractions that call for Fourier transform techniques. We develop two different NSA strategies based on two-dimensional plane strain ...

  10. Mechanical-engineering aspects of mirror-fusion technology

    International Nuclear Information System (INIS)

    Fisher, D.K.; Doggett, J.N.

    1982-01-01

    The mirror approach to magnetic fusion has evolved from the original simple mirror cell to today's mainline effort: the tandem-mirror machine with thermal barriers. Physics and engineering research is being conducted throughout the world, with major efforts in Japan, the USSR, and the US. At least one facility under construction (MFTF-B) will approach equivalent energy breakeven in physics performance. Significant mechanical engineering development is needed, however, before a demonstration reactor can be constructed. The principal areas crucial to mirror reactor development include large high-field superconducting magnets, high-speed continuous vacuum-pumping systems, long-pulse high-power neutral-beam and rf-plasma heating systems, and efficient high-voltage high-power direct converters. Other areas common to all fusion systems include tritium handling technology, first-wall materials development, and fusion blanket design

  11. Charged particle dynamics in axisymmetric nonconservative beams

    International Nuclear Information System (INIS)

    Radchenko, V.I.; Nikonov, O.I.

    1998-01-01

    Many of ion-beam technologies lead to the requirement of cross-section minimization of a particle beam in the object region acted upon, or to the problem of minimization of charged particle beam emittance (the growth rate of emittance) for a specified segment of the beam formation. In this paper we study the above problem for axisymmetric beams representing a nonconservative system of charged particles. It is shown that under certain assumptions the beam in question can be described by appropriate equations that possess an explicit solution. The latter allows one to study the influence of particle density distribution at the starting point on the future beam evolution. The results are based on approaches developed in J.D. Lawson (1977); V.I. Radchenko, G.D. Ved'manov (1995); O.I. Nikonov (1994). (orig.)

  12. Optimal cloning of qubits given by an arbitrary axisymmetric distribution on the Bloch sphere

    International Nuclear Information System (INIS)

    Bartkiewicz, Karol; Miranowicz, Adam

    2010-01-01

    We find an optimal quantum cloning machine, which clones qubits of arbitrary symmetrical distribution around the Bloch vector with the highest fidelity. The process is referred to as phase-independent cloning in contrast to the standard phase-covariant cloning for which an input qubit state is a priori better known. We assume that the information about the input state is encoded in an arbitrary axisymmetric distribution (phase function) on the Bloch sphere of the cloned qubits. We find analytical expressions describing the optimal cloning transformation and fidelity of the clones. As an illustration, we analyze cloning of qubit state described by the von Mises-Fisher and Brosseau distributions. Moreover, we show that the optimal phase-independent cloning machine can be implemented by modifying the mirror phase-covariant cloning machine for which quantum circuits are known.

  13. Corticospinal mirror neurons

    Science.gov (United States)

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others. PMID:24778371

  14. Advanced Mirror Technology Development

    Science.gov (United States)

    Stahl, H. Philip

    2017-01-01

    The Advanced Mirror Technology Development (AMTD) project matures critical technologies required to enable ultra-stable 4-m-or-larger monolithic or segmented ultraviolet, optical, and infrared (UVOIR) space telescope primary-mirror assemblies for general astrophysics and ultra-high-contrast observations of exoplanets.

  15. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

  16. Generalized Magnetic Mirrors.

    Science.gov (United States)

    Liu, Wei

    2017-09-22

    We propose generalized magnetic mirrors that can be achieved by excitations of sole electric resonances. Conventional approaches to obtain magnetic mirrors rely heavily on exciting the fundamental magnetic dipoles, whereas here we reveal that, besides magnetic resonances, electric resonances of higher orders can be also employed to obtain highly efficient magnetic mirrors. Based on the electromagnetic duality, it is also shown that electric mirrors can be achieved by exciting magnetic resonances. We provide direct demonstrations of the generalized mirrors proposed in a simple system of a one-dimensional periodic array of all-dielectric wires, which may shed new light on many advanced fields of photonics related to resonant multipolar excitations and interferences.

  17. Electron cyclotron emission diagnostics for mirror devices (invited)

    International Nuclear Information System (INIS)

    Ellis, R.F.; James, R.A.; Lasnier, C.J.; Casper, T.

    1985-01-01

    Electron cyclotron emission (ECE) has proven to be a useful diagnostic in tokamaks for measuring T/sub e/ and its radial variation. The application of ECE to mirror devices is discussed here, with emphasis on measurements of the properties of energetic electrons in tandem mirror end cells, which can be viewed both parallel and perpendicular to B. The parallel or whistler view is generally optically thick and can yield a measurement of perpendicular temperature. High harmonic perpendicular emission is optically thin and can yield important information about the hot electron buildup and the energy and spatial distribution. Experimental results from TMX-U and appropriate modeling are presented

  18. Classical mirror symmetry

    CERN Document Server

    Jinzenji, Masao

    2018-01-01

    This book furnishes a brief introduction to classical mirror symmetry, a term that denotes the process of computing Gromov–Witten invariants of a Calabi–Yau threefold by using the Picard–Fuchs differential equation of period integrals of its mirror Calabi–Yau threefold. The book concentrates on the best-known example, the quintic hypersurface in 4-dimensional projective space, and its mirror manifold. First, there is a brief review of the process of discovery of mirror symmetry and the striking result proposed in the celebrated paper by Candelas and his collaborators. Next, some elementary results of complex manifolds and Chern classes needed for study of mirror symmetry are explained. Then the topological sigma models, the A-model and the B-model, are introduced. The classical mirror symmetry hypothesis is explained as the equivalence between the correlation function of the A-model of a quintic hyper-surface and that of the B-model of its mirror manifold. On the B-model side, the process of construct...

  19. Two-dimensional axisymmetric and three-dimensional helical equilibrium in the line-tied screw pinch

    Science.gov (United States)

    Paz-Soldan, Carlos; Brookhart, M. I.; Clinch, A. J.; Hannum, D. A.; Forest, C. B.

    2011-10-01

    The line-tying condition at a conducting anode is shown to provide a localized modification to the well-understood 1-D screw pinch equilibrium in the presence of bulk plasma diamagnetism. Diamagnetic currents cannot flow near the conducting anode and are measured to disappear in a localized boundary layer, causing a weak mirror configuration that breaks 1-D equilibrium and causes large parallel pressure gradients suggestive of significant radial outflows. For sufficiently large plasma currents, the paramagnetic nature of parallel current drives the equilibrium to paramagnetism and destroys the mirror effect. At a critical plasma current the axisymmetric equilibrium is found to transition to a long-lived, rotating, helical 3-D equilibrium state. Internal measurements of this state via multi-point correlation analysis techniques illustrate that it preserves the flux surfaces and pressure profile of the axisymmetric equilibrium. Measurements indicate that despite the fact that the flux surfaces wander at the anode, the line-tied boundary conditions are not necessarily violated. Supported by Department of Energy grant #DE-FG02-00ER54603, National Science Foundation grant #0903900, and the Natural Sciences and Engineering Research Council of Canada

  20. bessel functions for axisymmetric elasticity problems of the elastic

    African Journals Online (AJOL)

    HOD

    . ) ( ) r. (. ) ( ). The governing partial differential equation for axisymmetric elasticity problems are the strain- displacement equations, the differential equations of equilibrium and the material constitutive laws, subject to the displacement and ...

  1. Nanolaminate deformable mirrors

    Science.gov (United States)

    Papavasiliou, Alexandros P.; Olivier, Scot S.

    2009-04-14

    A deformable mirror formed out of two layers of a nanolaminate foil attached to a stiff substrate is introduced. Deformation is provided by an electrostatic force between two of the layers. The internal stiffness of the structure allows for high-spatial-frequency shapes. The nanolaminate foil of the present invention allows for a high-quality mirror surface. The device achieves high precision in the vertical direction by using foils with accurately controlled thicknesses, but does not require high precision in the lateral dimensions, allowing such mirrors to be fabricated using crude lithography techniques. Such techniques allow structures up to about the meter scale to be fabricated.

  2. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  3. Departures from Axisymmetric Balance Dynamics during Secondary Eyewall Formation

    Science.gov (United States)

    2014-10-01

    tangential wind tendencies of the mesoscale integration with those diagnosed as the axisymmetric balanced response of a vortex subject to diabatic ...the mesoscale integration with those diagnosed as the axisymmetric balanced response of a vortex subject to diabatic and tangential momentum forcing...secondary circulation will develop to oppose the forcing of diabatic heating and/or friction. After the seminal work of Eliassen (1951), a number of

  4. Computational study of axisymmetric modes in noncircular cross section tokamaks

    International Nuclear Information System (INIS)

    Johnson, J.L.; Chance, M.S.; Greene, J.M.; Grimm, R.C.; Jardin, S.C.; Kerner, W.; Manickam, J.; Weimer, K.E.

    1976-09-01

    A major computational program to investigate the MHD equilibrium, stability, and nonlinear evolution properties of realistic tokamak configurations is proceeding. Preliminary application is made to the Princeton PDX device. Both axisymmetric (n = 0) modes and kink (n = 1) modes are found; the growth rates depend sensitively on the configuration. A study of the nonlinear evolution of axisymmetric modes in such a device shows that flux conservation in the vacuum region can limit their growth

  5. [Mirror behaviors in dementia: the many mirror signs].

    Science.gov (United States)

    Ghika, Joseph; Diéguez, Sebastian; Assal, Frédéric; Demonet, Jean-François

    2013-11-13

    Mirror behaviors in advanced dementia are: the mirror sign of Abely and Delmas, where the patient stares at his face (environment-driven behavior of Lhermitte); non recognition of the self in the mirror (autoprosopagnosia and/or delirious auto-Capgras); mirror agnosia of Ramachandran and Binkofski where the patient do not understand the concept of mirror and its use; the psychovisual reflex, or reflex pursuit of the eyes when passively moving a minrror in front of a patient (intact vision); mirror writing (procedural learning). We describe four demented patients with mirror behaviors assessing brain mechanisms of self recognition, social brain and mental and visuo-spatial manipulation of images and objects.

  6. Rotational Motion of Axisymmetric Marangoni Swimmers

    Science.gov (United States)

    Rothstein, Jonathan; Uvanovic, Nick

    2017-11-01

    A series of experiments will be presented investigating the motion of millimeter-sized particles on the surface of water. The particles were partially coated with ethanol and carefully placed on a water interface in a series of Petri dishes with different diameters. High speed particle motion was driven by strong surface tension gradients as the ethanol slowly diffuses from the particles into the water resulting in a Marangoni flow. The velocity and acceleration of the particles where measured. In addition to straight line motion, the presence of the bounding walls of the circular Petri dish was found to induce an asymmetric, rotational motion of the axisymmetric Marangoni swimmers. The rotation rate and radius of curvature was found to be a function of the size of the Petri dish and the curvature of the air-water interface near the edge of the dish. For large Petri dishes or small particles, rotation motion was observed far from the bounding walls. In these cases, the symmetry break appears to be the result of the onset of votex shedding. Finally, multiple spherical particles were observed to undergo assembly driven by capillary forces followed by explosive disassembly.

  7. Composite Material Mirror Testing

    Science.gov (United States)

    2000-01-01

    In this photograph, the composite material mirror is tested in the X-Ray Calibration Facility at the Marshall Space Flight Center for the James Webb Space Telescope (JWST). The mirror test conducted was to check the ability to accurately model and predict the cryogenic performance of complex mirror systems, and the characterization of cryogenic dampening properties of beryllium. The JWST, a next generation successor to the Hubble Space Telescope (HST), was named in honor of James W. Webb, NASA's second administrator, who led NASA in the early days of the fledgling Aerospace Agency. Scheduled for launch in 2010 aboard an expendable launch vehicle, the JWST will be able to look deeper into the universe than the HST because of the increased light-collecting power of its larger mirror and the extraordinary sensitivity of its instrument to infrared light.

  8. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  9. Mirror reactor surface study

    International Nuclear Information System (INIS)

    Hunt, A.L.; Damm, C.C.; Futch, A.H.; Hiskes, J.R.; Meisenheimer, R.G.; Moir, R.W.; Simonen, T.C.; Stallard, B.W.; Taylor, C.E.

    1976-01-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included

  10. Cryogenic Active Mirrors

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort seeks to develop active mirrors that can correct for thermally-induced figure deformations upon cooling from room-temperature at the time of manufacture,...

  11. Mirror fermions and cosmology

    International Nuclear Information System (INIS)

    Senjanovic, G.; Virginia Polytechnic Inst. and State Univ., Blacksburg

    1984-07-01

    Extended supersymmetry, Kaluza-Klein theory and family unification all suggest the existence of mirror fermions, with same quantum numbers but opposite helicities from ordinary fermions. The laboratory and especially cosmological implications of such particles are reviewed and summarized. (author)

  12. Manufacturing parabolic mirrors

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    The photo shows the construction of a vertical centrifuge mounted on an air cushion, with a precision of 1/10000 during rotation, used for the manufacture of very high=precision parabolic mirrors. (See Annual Report 1974.)

  13. Corticospinal mirror neurons

    OpenAIRE

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like p...

  14. Geometry of mirror manifolds

    International Nuclear Information System (INIS)

    Aspinwall, P.S.; Luetken, C.A.

    1991-01-01

    We analyze the mirror manifold hypothesis in one and three dimensions using the simplest available representations of the N = 2 superconformal algebra. The symmetries of these tensor models can be divided out to give an explicit representation of the mirror, and we give a simple group theoretical algorithm for determining which symmetries should be used. We show that the mirror of a superconformal field theory does not always have a geometrical interpretation, but when it does, deformations of complex structure of one manifold are reflected in deformations of the Kaehler form of the mirror manifold, and we show how the large radius limit of a manifold corresponds to a large complex structure limit in the mirror manifold. The mirror of the Tian-Yau three generation model is constructed both as a conformal field theory and as an algebraic variety with Euler number six. The Hodge numbers of this manifolds are fixed, but the intersection numbes are highly ambiguous, presumably reflected a rich structure of multicritical points in the moduli space of the field theory. (orig.)

  15. Analytic modeling of axisymmetric disruption halo currents

    International Nuclear Information System (INIS)

    Humphreys, D.A.; Kellman, A.G.

    1999-01-01

    Currents which can flow in plasma facing components during disruptions pose a challenge to the design of next generation tokamaks. Induced toroidal eddy currents and both induced and conducted poloidal ''halo'' currents can produce design-limiting electromagnetic loads. While induction of toroidal and poloidal currents in passive structures is a well-understood phenomenon, the driving terms and scalings for poloidal currents flowing on open field lines during disruptions are less well established. A model of halo current evolution is presented in which the current is induced in the halo by decay of the plasma current and change in enclosed toroidal flux while being convected into the halo from the core by plasma motion. Fundamental physical processes and scalings are described in a simplified analytic version of the model. The peak axisymmetric halo current is found to depend on halo and core plasma characteristics during the current quench, including machine and plasma dimensions, resistivities, safety factor, and vertical stability growth rate. Two extreme regimes in poloidal halo current amplitude are identified depending on the minimum halo safety factor reached during the disruption. A 'type I' disruption is characterized by a minimum safety factor that remains relatively high (typically 2 - 3, comparable to the predisruption safety factor), and a relatively low poloidal halo current. A 'type II' disruption is characterized by a minimum safety factor comparable to unity and a relatively high poloidal halo current. Model predictions for these two regimes are found to agree well with halo current measurements from vertical displacement event disruptions in DIII-D [T. S. Taylor, K. H. Burrell, D. R. Baker, G. L. Jackson, R. J. La Haye, M. A. Mahdavi, R. Prater, T. C. Simonen, and A. D. Turnbull, open-quotes Results from the DIII-D Scientific Research Program,close quotes in Proceedings of the 17th IAEA Fusion Energy Conference, Yokohama, 1998, to be published in

  16. Surface micromachined scanning mirrors

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1992-01-01

    Both aluminum cantilever and torsional scanning mirrors have been fabricated and their static and dynamic properties are studied experimentally and theoretically. The experiments showed resonance frequencies in the range of 163 k-Hz - 632 kHz for cantilever beams with Q values between 5 and 11....... Torsional mirrors showed resonance frequencies in the range of 410 kHz - 667 kHz with Q values of 10 - 17. All measurements performed at atmospheric pressure. Both types of mechanical structures were deflected electrostatically at large angles (± 5°) more than 1011 times without breaking and without any...

  17. A Conceptual Mirror

    DEFF Research Database (Denmark)

    Badie, Farshad

    2017-01-01

    product of the constructivist interactions. The most significant matter in meaning construction is producing the own meaningful comprehension, realisation and understanding. Here the learner gets to know how to develop her/his thinking. In this research, I will focus on relating (i) meaning construction...... will analyse the logical dependencies between learner and men- tor and will check their reflectional symmetrical relationship in a conceptual mirror. The conceptual mirror is a phenomenon that represents the meeting point of the mentor’s and the learner’s conceptual knowledge....

  18. Amorphous Metals and Composites as Mirrors and Mirror Assemblies

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Davis, Gregory L. (Inventor); Agnes, Gregory S. (Inventor); Shapiro, Andrew A. (Inventor)

    2016-01-01

    A mirror or mirror assembly fabricated by molding, pressing, assembling, or depositing one or more bulk metal glass (BMG), bulk metal glass composite (BMGMC), or amorphous metal (AM) parts and where the optical surface and backing of the mirror can be fabricated without machining or polishing by utilizing the unique molding capabilities of this class of materials.

  19. The Mirror MMDBMS architecture

    NARCIS (Netherlands)

    de Vries, A.P.; van Doorn, M.G.L.M.; Blanken, Henk; Apers, Peter M.G.

    Handling large collections of digitized multimedia data, usually referred to as multimedia digital libraries, is a major challenge for information technology. The Mirror DBMS is a research database system that is developed to better understand the kind of data management that is required in the

  20. Introduction: Mirrors of Passing

    DEFF Research Database (Denmark)

    Seebach, Sophie Hooge; Willerslev, Rane

    Gaiman’s The Graveyard Book, we explore how the world of the dead and the world of the living can intersect; how time and materiality shifts and changes depending on who experiences it. These revelations, based on fiction, provide a mirror through which the reader can experience the varied chapters...

  1. Rearview Mirror Dimming Function

    Science.gov (United States)

    Layton, William

    2011-01-01

    Students are often unaware of the little tab on a rear-view mirror that is used to dim headlights from the rear. Those who know about this tab are usually interested in knowing how it works. Explanations of the optics involved can be found in Serway and Jewett and Jones and Edge. An alternate explanation is given.

  2. Mirror reactor blankets

    International Nuclear Information System (INIS)

    Lee, J.D.; Barmore, W.L.; Bender, D.J.; Doggett, J.N.; Galloway, T.R.

    1976-01-01

    The general requirements of a breeding blanket for a mirror reactor are described. The following areas are discussed: (1) facility layout and blanket maintenance, (2) heat transfer and thermal conversion system, (3) materials, (4) tritium containment and removal, and (5) nuclear performance

  3. Physics of mirror fusion systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1976-01-01

    Recent experimental results with the 2XIIB mirror machine at Lawrence Livermore Laboratory have demonstrated the stable confinement of plasmas at fusion temperatures and with energy densities equaling or exceeding that of the confining fields. The physics of mirror confinement is discussed in the context of these new results. Some possible approaches to further improving the confinement properties of mirror systems and the impact of these new approaches on the prospects for mirror fusion reactors are discussed

  4. Mirror reactor studies

    International Nuclear Information System (INIS)

    Moir, R.W.; Barr, W.L.; Bender, D.J.

    1977-01-01

    Design studies of a fusion mirror reactor, a fusion-fission mirror reactor, and two small mirror reactors are summarized. The fusion reactor uses 150-keV neutral-beam injectors based on the acceleration of negative ions. The injectors provide over 1 GW of continuous power at an efficiency greater than 80%. The fusion reactor has three-stage, modularized, Venetian blind, plasma direct converter with a predicted efficiency of 59% and a new concept for removal of the lune-shaped blanket: a crane is brought between the two halves of the Yin-Yang magnet, which are separated by a float. The design has desirable features such as steady-state operation, minimal impurity problems, and low first-wall thermal stress. The major disadvantage is low Q resulting in high re-circulating power and hence high cost of electrical power. However, the direct capital cost per unit of gross electrical power is reasonable [$1000/kW(e)]. By contrast, the fusion-fission reactor design is not penalized by re-circulating power and uses relatively near-term fusion technology being developed for the fusion power program. New results are presented on the Th- 233 U and the U- 239 Pu fuel cycles. The purpose of this hybrid is fuel production, with projected costs at $55/g of Pu or $127/g of 233 U. Blanket and cooling system designs, including an emergency cooling system, by General Atomic Company, lead us to the opinion that the reactor can meet expected safety standards for licensing. The smallest mirror reactor having only a shield between the plasma and the coil is the 4.2-m long fusion engineering research facility (FERF) designed for material irradiation. The smallest mirror reactor having both a blanket and shield is the 7.5-m long experimental power reactor (EPR), which has both a fusion and a fusion-fission version. (author)

  5. On the variational approach to axisymmetric magnetohydrodynamic equilibria

    International Nuclear Information System (INIS)

    Andreussi, T.; Pegoraro, F.

    2008-01-01

    The variational formulation of the axisymmetric magnetohydrodynamic equilibrium equations with plasma flows is addressed and a more comprehensive method is presented that allows, in particular, for open boundary conditions and discontinuous (shock) solutions. A numerical procedure based on the variational formulation is described and a validation test for an open conical geometry, including also hydrodynamic shocks, is investigated.

  6. Non-Radial Oscillations in an Axisymmetric MHD Incompressible Fluid

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... ... oscillations by perturbing the MHD equilibrium solution for an axisymmetric incompressible fluid. The fluid motion and the magnetic field are expressed as scalars , , and , respectively. In deriving the exact solution for the equilibrium state, we neglect the contribution due to meridional circulation.

  7. Axisymmetric Lattice Boltzmann Model of Droplet Impact on Solid Surfaces

    Science.gov (United States)

    Dalgamoni, Hussein; Yong, Xin

    2017-11-01

    Droplet impact is a ubiquitous fluid phenomena encountered in scientific and engineering applications such as ink-jet printing, coating, electronics manufacturing, and many others. It is of great technological importance to understand the detailed dynamics of drop impact on various surfaces. The lattice Boltzmann method (LBM) emerges as an efficient method for modeling complex fluid systems involving rapidly evolving fluid-fluid and fluid-solid interfaces with complex geometries. In this work, we model droplet impact on flat solid substrates with well-defined wetting behavior using a two-phase axisymmetric LBM with high density and viscosity contrasts. We extend the two-dimensional Lee and Liu model to capture axisymmetric effect in the normal impact. First we compare the 2D axisymmetric results with the 2D and 3D results reported by Lee and Liu to probe the effect of axisymmetric terms. Then, we explore the effects of Weber number, Ohnesorge number, and droplet-surface equilibrium contact angle on the impact. The dynamic contact angle and spreading factor of the droplet during impact are investigated to qualitatively characterize the impact dynamics.

  8. Modelling axisymmetric cod-ends made of different mesh types

    DEFF Research Database (Denmark)

    Priour, D.; Herrmann, Bent; O'Neill, F.G.

    2009-01-01

    Cod-ends are the rearmost part of trawl fishing gears. They collect the catch, and for many important species it is where fish selection takes place. Generally speaking they are axisymmetric, and their shape is influenced by the catch volume, the mesh shape, and the material characteristics. The ...

  9. Non-Axisymmetric Shaping of Tokamaks Preserving Quasi-Axisymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Long-Poe Ku and Allen H. Boozer

    2009-06-05

    If quasi-axisymmetry is preserved, non-axisymmetric shaping can be used to design tokamaks that do not require current drive, are resilient to disruptions, and have robust plasma stability without feedback. Suggestions for addressing the critical issues of tokamaks can only be validated when presented with sufficient specificity that validating experiments can be designed. The purpose of this paper is provide that specificity for non-axisymmetric shaping. To our knowledge, no other suggestions for the solution of a number of tokamak issues, such as disruptions, have reached this level of specificity. Sequences of three-field-period quasi-axisymmetric plasmas are studied. These sequences address the questions: (1) What can be achieved at various levels of non-axisymmetric shaping? (2) What simplifications to the coils can be achieved by going to a larger aspect ratio? (3) What range of shaping can be achieved in a single experimental facility? The sequences of plasmas found in this study provide a set of interesting and potentially important configurations.

  10. Technology of direct conversion for mirror reactor end-loss plasma

    International Nuclear Information System (INIS)

    Barr, W.L.; Moir, R.W.

    1980-01-01

    Design concepts are presented for plasma direct convertors (PDC) intended primarily for use on the end-loss plasma from tandem-mirror reactors. Recent experimental results confirm most of these design concepts. Both a one-stage and a two-stage PDC were tested in reactor-like conditions using a 100-kV, 6-kW ion beam. In a separate test on the end of the TMX machine, a single stage PDC recovered 79 W for a net efficiency of 50%. Tandem mirror devices are well suited to PDC. The high minimum energy of the end-loss ions, the magnetic expansion outside the mirrors, and the vacuum conditions in the end tanks required by the confined plasma, all preexist. The inclusion of a PDC is therefore a rather small addition. These facts and the scale parameters for a PDC are discussed

  11. Rapidly convergent algorithms for 3-D tandem and stellarator equilibria in the paraxial approximation

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, B.

    1984-04-01

    Tandem and stellarator equilibria at high ..beta.. have proved hard to compute and the relaxation methods of Bauer et al., Chodura and Schluter, Hirshman, Strauss, and Pearlstein et al. have been slow to converge. This paper reports an extension of the low-..beta.. analytic method of Pearlstein, Kaiser, and Newcomb to arbitrary ..beta.. for tandem mirrors which converges in 10 to 20 iterations. Extensions of the method to stellarator equilibria are proposed and are very close to the analytic method of Johnson and Greene - the stellarator expansion. Most of the results of all these calculations can be adequately described by low-..beta.. approximations since the MHD stability limits occur at low ..beta... The tandem mirror, having weak curvature and a long central cell, allows finite Larmor radius effects to eliminate most ballooning modes and offers the possibility of really high average ..beta... This is the interest in developing such three-dimensional numerical algorithms.

  12. Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Dixon, F.P.

    1977-01-01

    On October 1, 1977 work began at LLL on the Mirror Fusion Test Facility (MFTF), an advanced experimental fusion device. Scheduled for operation in late 1981, MFTF is designed as an intermediate step between present mirror machines, such as 2XIIB, and an experimental fusion reactor. This design incorporates improved technology and a better theoretical understanding of how neutral beam injection, plasma guns, and gas injection into the plasma region compensate for cooling and particle losses. With the new facility, we expect to achieve a confinement factor (n tau) of 10 12 particles . sm/cm 3 --a tenfold increase over 2XIIB n tau values--and to increase plasma temperature to over 500 million K. The following article describes this new facility and reports on progress in some of the R and D projects that are providing the technological base for its construction

  13. Tinbergen on mirror neurons

    OpenAIRE

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology—the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that ...

  14. BN-350 ''Mirror System''

    International Nuclear Information System (INIS)

    Thornton, A.L.; Halbig, J.K.

    2004-01-01

    The BN-350 Unattended Monitoring System plays an important role for the Safeguards Department of the International Atomic Energy Agency (IAEA). In 1998, the Los Alamos National Laboratory, in conjunction with the IAEA and sponsored by the US Department of Energy, designed and installed an integrated multi-instrument safeguards system at the BN-350 reactor in Aktau, Kazakhstan, to monitor spent-fuel and blanket assembly conditioning and canning activities. The purpose of the system was to provide effective safeguards at this facility while reducing the manpower load on the IAEA. The system is composed of many individual nondestructive analysis and surveillance components, each having a unique function and working together to provide fully unattended measurement of spent-fuel assemblies. The BN-350 ''Mirror System'' was built to provide a similar system with like components at the IAEA Headquarters in Vienna to facilitate analysis and/or simulation of problems that might occur in the field and for training inspectors and other technical staff in preparation for their work in the field. In addition, the system is used to test new equipment and qualify new or modified software. This paper describes the main components of the Mirror System, how the components are integrated, and how the Mirror System has benefited the IAEA.

  15. Mirror reactor studies

    International Nuclear Information System (INIS)

    Moir, R.W.; Barr, W.L.; Bender, D.J.

    1976-01-01

    Design studies of a fusion mirror reactor, a fusion-fission mirror reactor, and two small mirror reactors are summarized. The fusion reactor uses 150-keV neutral-beam injectors based on the acceleration of negative ions. The injectors provide over 1 GW of continuous power at an efficiency greater than 80 percent. The fusion reactor has three-stage, modularized, Venetian blind, plasma direct converter with a predicted efficiency of 59 percent and a new concept for removal of the lune-shaped blanket: a crane is brought between the two halves of the Yin-Yang magnet, which are separated by a float. The design has desirable features such as steady-state operation, minimal impurity problems, and low first-wall thermal stress. The major disadvantage is low Q resulting in high recirculating power and hence high cost of electrical power. However, the direct capital cost per unit of gross electrical power is reasonable [$1000/kW(e)

  16. Enzyme catalysed tandem reactions

    OpenAIRE

    Oroz-Guinea, Isabel; García-Junceda, Eduardo

    2013-01-01

    To transfer to the laboratory, the excellent efficiency shown by enzymes in Nature, biocatalysis, had to mimic several synthetic strategies used by the living organisms. Biosynthetic pathways are examples of tandem catalysis and may be assimilated in the biocatalysis field for the use of isolated multi-enzyme systems in the homogeneous phase. The concurrent action of several enzymes that work sequentially presents extraordinary advantages from the synthetic point of view, since it permits a r...

  17. The tandem betatron accelerator

    International Nuclear Information System (INIS)

    Keinigs, R.

    1991-01-01

    This paper reports that the tandem betatron is a compact, high-current induction accelerator that has the capability to accelerate electrons to an energy of order one gigavolt. Based upon the operating principle of a conventional betatron, the tandem betatron employs two synchronized induction cores operating 180 degrees out of phase. Embedded within the cores are the vacuum chambers, and these are connected by linear transport sections to allow for moving the beam back and forth between the two betatrons. The 180 degree phase shift between the core fluxes permits the circumvention of the flux swing constraint that limits the maximum energy gain of a conventional betatron. By transporting the beam between the synchronized cores, an electron can access more than one acceleration cycle, and thereby continue to gain energy. This added degree of freedom also permits a significant decrease in the size of the magnet system. Biasing coils provide independent control of the confining magnetic field. Provided that efficient beam switching can be performed, it appears feasible that a one gigavolt electron beam can be generated and confined. At this energy, a high current electron beam circulating in a one meter radius orbit could provide a very intense source of short wavelength (λ < 10 nm) synchrotron radiation. This has direct application to the emerging field of x-ray lithography. At more modest energies (10 MeV-30 MEV) a compact tandem betatron could be employed in the fields of medical radiation therapy, industrial radiography, and materials processing

  18. Relating the "mirrorness" of mirror neurons to their origins.

    Science.gov (United States)

    Kilner, James M; Friston, Karl J

    2014-04-01

    Ever since their discovery, mirror neurons have generated much interest and debate. A commonly held view of mirror neuron function is that they transform "visual information into knowledge," thus enabling action understanding and non-verbal social communication between con-specifics (Rizzolatti & Craighero 2004). This functionality is thought to be so important that it has been argued that mirror neurons must be a result of selective pressure.

  19. Thermal effects on beryllium mirrors

    International Nuclear Information System (INIS)

    Weinswig, S.

    1989-01-01

    Beryllium is probably the most frequently used material for spaceborne system scan mirrors. Beryllium's properties include lightweightedness, high Young's modulus, high stiffness value, high resonance value. As an optical surface, beryllium is usually nickel plated in order to produce a higher quality surface. This process leads to the beryllium mirror acting like a bimetallic device. The mirror's deformation due to the bimetallic property can possibly degrade the performance of the associated optical system. As large space borne systems are designed and as temperature considerations become more crucial in the instruments, the concern about temporal deformation of the scan mirrors becomes a prime consideration. Therefore, two sets of tests have been conducted in order to ascertain the thermal effects on nickel plated beryllium mirrors. These tests are categorized. The purpose of this paper is to present the values of the bimetallic effect on typical nickel plated beryllium mirrors

  20. Report of the workshop on rf heating in mirror systems

    International Nuclear Information System (INIS)

    Price, R.E.; Woo, J.T.

    1980-08-01

    This report is prepared from the proceedings of the Workshop on RF Heating in Magnetic Mirror Systems held at DOE Headquarters in Washington, DC, on March 10-12, 1980. The workshop was organized into four consecutive half-day sessions of prepared talks and one half-day discussion. The first session on tandem mirror concepts and program plans served to identify the opportunities for the application of rf power and the specific approaches that are being pursued. A summary of the ideas presented in this session is given. The following sessions of the workshop were devoted to an exposition of current theoretical and experimental knowledge on the interaction of rf power with magnetically confined, dense, high temperature plasmas at frequencies near the electron cyclotron resonance, lower hybrid resonance and ion cyclotron resonance (including magnetosonic) ranges. The conclusions from these proceedings are presented

  1. Complex/Symplectic Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Wu-yen; Kachru, Shamit; /Stanford U., ITP /SLAC; Tomasiello, Alessandro; /Stanford U., ITP

    2005-10-28

    We construct a class of symplectic non-Kaehler and complex non-Kaehler string theory vacua, extending and providing evidence for an earlier suggestion by Polchinski and Strominger. The class admits a mirror pairing by construction. Comparing hints from a variety of sources, including ten-dimensional supergravity and KK reduction on SU(3)-structure manifolds, suggests a picture in which string theory extends Reid's fantasy to connect classes of both complex non-Kaehler and symplectic non-Kaehler manifolds.

  2. Multilayer Active Shell Mirrors

    Science.gov (United States)

    Steeves, John

    This thesis presents a novel active mirror technology based on carbon fiber composites and replication manufacturing processes. Multiple additional layers are implemented into the structure in order to provide the reflective layer, actuation capabilities and electrode routing. The mirror is thin, lightweight, and has large actuation capabilities. These features, along with the associated manufacturing processes, represent a significant change in design compared to traditional optics. Structural redundancy in the form of added material or support structures is replaced by thin, unsupported lightweight substrates with large actuation capabilities. Several studies motivated by the desire to improve as-manufactured figure quality are performed. Firstly, imperfections in thin CFRP laminates and their effect on post-cure shape errors are studied. Numerical models are developed and compared to experimental measurements on flat laminates. Techniques to mitigate figure errors for thicker laminates are also identified. A method of properly integrating the reflective facesheet onto the front surface of the CFRP substrate is also presented. Finally, the effect of bonding multiple initially flat active plates to the backside of a curved CFRP substrate is studied. Figure deformations along with local surface defects are predicted and characterized experimentally. By understanding the mechanics behind these processes, significant improvements to the overall figure quality have been made. Studies related to the actuation response of the mirror are also performed. The active properties of two materials are characterized and compared. Optimal active layer thicknesses for thin surface-parallel schemes are determined. Finite element simulations are used to make predictions on shape correction capabilities, demonstrating high correctabiliity and stroke over low-order modes. The effect of actuator saturation is studied and shown to significantly degrade shape correction performance. The

  3. Status report on mirror alternatives

    International Nuclear Information System (INIS)

    Condit, W.C.; Fowler, T.K.; Post, R.F.

    1976-01-01

    The present status of studies at Lawrence Livermore Laboratory (LLL) directed toward exploring variants on the basic magnetic mirror confinement concept is described. These studies have emphasized those ideas that could lead most directly to improvements in the scientific and economic viability of fusion reactors based on the mirror concept, within the general context of the extensive body of specialized physics and technology that has been developed in the course of the Mirror Program

  4. Axisymmetric instability in a noncircular tokamak: experiment and theory

    International Nuclear Information System (INIS)

    Lipschultz, B.; Prager, S.C.; Todd, A.M.M.; Delucia, J.

    1979-09-01

    The stability of dee, inverse-dee and square cross section plasmas to axisymmetric modes has been investigated experimentally in Tokapole II, a tokamak with a four-null poloidal divertor. Experimental results are closely compared with predictions of two numerical stability codes -- the PEST code (ideal MHD, linear stability) adapted to tokapole geometry and a code which follows the nonlinear evolution of shapes similar to tokapole equilibria. Experimentally, the square is vertically stable and both dee's unstable to a vertical nonrigid axisymmetric shift. The central magnetic axis displacement grows exponentially with a growth time approximately 10 3 poloidal Alfven times plasma time. Proper initial positioning of the plasma on the midplane allows passive feedback to nonlinearly restore vertical motion to a small stable oscillation. Experimental poloidal flux plots are produced directly from internal magnetic probe measurements

  5. Fluid simulations of edge turbulence for stellarators and axisymmetric configurations

    Science.gov (United States)

    Kleiber, R.; Scott, B.

    2005-10-01

    Nonlinear electromagnetic fluid simulations in a flux tube are used to compute the edge turbulence for a family of axisymmetric configurations with different rotational transform profiles (ι) and the stellarator Wendelstein 7-X (W7-X) [Grieger et al., Plasma Physics and Controlled Nuclear Fusion Research, 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 525]. The influence of the ι profile on anomalous transport and the strength of zonal flows in these axisymmetric equilibria are studied and the results are connected to simulations for the W7-X equilibrium. A strong decrease in transport is found by increasing ι or switching the sign of the shear from tokamak-(ι'0). The effect of pressure-induced changes in the W7-X equilibrium geometry on the transport at fixed parameters is studied and a decrease in the transport following changes in the zonal flows is found.

  6. Stability of flow over axisymmetric bodies with porous suction strips

    Science.gov (United States)

    Nayfeh, A. H.; Reed, H. L.

    1982-01-01

    Linear triple deck, closed form solutions for mean-flow quantities are developed for axisymmetric incompressible flow past a body with porous strips. The solutions account for upstream influence and are linear superpositions of the flow past the body without suction plus the perturbations due to the suction strips. Flow past the suctionless body is calculated using the Transition Analysis Program System, and a simple linear optimization scheme to determine number, spacing, and mass flow rate through the strips on an axisymmetric body is developed using the linear, triple-deck, closed-form solutions. The theory is demonstrated by predicting optimal strip distributions, and the effect of various adverse pressure-gradient situations on stability is studied.

  7. Small Engine Technology (SET) - Task 14 Axisymmetric Engine Simulation Environment

    Science.gov (United States)

    Miller, Max J.

    1999-01-01

    As part of the NPSS (Numerical Propulsion Simulation System) project, NASA Lewis has a goal of developing an U.S. industry standard for an axisymmetric engine simulation environment. In this program, AlliedSignal Engines (AE) contributed to this goal by evaluating the ENG20 software and developing support tools. ENG20 is a NASA developed axisymmetric engine simulation tool. The project was divided into six subtasks which are summarized below: Evaluate the capabilities of the ENG20 code using an existing test case to see how this procedure can capture the component interactions for a full engine. Link AE's compressor and turbine axisymmetric streamline curvature codes (UD0300M and TAPS) with ENG20, which will provide the necessary boundary conditions for an ENG20 engine simulation. Evaluate GE's Global Data System (GDS), attempt to use GDS to do the linking of codes described in Subtask 2 above. Use a turbofan engine test case to evaluate various aspects of the system, including the linkage of UD0300M and TAPS with ENG20 and the GE data storage system. Also, compare the solution results with cycle deck results, axisymmetric solutions (UD0300M and TAPS), and test data to determine the accuracy of the solution. Evaluate the order of accuracy and the convergence time for the solution. Provide a monthly status report and a final formal report documenting AE's evaluation of ENG20. Provide the developed interfaces that link UD0300M and TAPS with ENG20, to NASA. The interface that links UD0300M with ENG20 will be compatible with the industr,, version of UD0300M.

  8. Superconducting (radiation hardened) magnets for mirror fusion devices

    International Nuclear Information System (INIS)

    Henning, C.D.; Dalder, E.N.C.; Miller, J.R.; Perkins, J.R.

    1983-01-01

    Superconducting magnets for mirror fusion have evolved considerably since the Baseball II magnet in 1970. Recently, the Mirror Fusion Test Facility (MFTF-B) yin-yang has been tested to a full field of 7.7 T with radial dimensions representative of a full scale reactor. Now the emphasis has turned to the manufacture of very high field solenoids (choke coils) that are placed between the tandem mirror central cell and the yin-yang anchor-plug set. For MFTF-B the choke coil field reaches 12 T, while in future devices like the MFTF-Upgrade, Fusion Power Demonstration and Mirror Advanced Reactor Study (MARS) reactor the fields are doubled. Besides developing high fields, the magnets must be radiation hardened. Otherwise, thick neutron shields increase the magnet size to an unacceptable weight and cost. Neutron fluences in superconducting magnets must be increased by an order of magnitude or more. Insulators must withstand 10 10 to 10 11 rads, while magnet stability must be retained after the copper has been exposed to fluence above 10 19 neutrons/cm 2

  9. Plasma surface interactions in Q-enhanced mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1978-01-01

    Two approaches to enhancement of the Q (energy gain) factor of mirror systems are under study at Livermore. These include the Tandem Mirror and the Field Reversed Mirror. Both of these new ideas preserve features of conventional mirror systems as far as plasma-wall interactions are concerned. Specifically in both approaches field lines exit from the ends of the system and impinge on walls located at a distance from the confinement chamber. It is possible to predict some aspects of the plasma/surface interactions of TM and FRM systems from experience obtained in the Livermore 2XIIB experiment. In particular, as observed in 2XIIB, effective isolation of the plasma from thermal contact with the ends owing to the development of sheath-like regions is to be expected. Studies presently underway directed toward still further enhancing the decoupling of the plasma from the effects of plasma surface interactions at the walls will be discussed, with particular reference to the problem of minimizing the effects of refluxing secondary electrons produced by plasma impact on the end walls

  10. Modeling axisymmetric flows dynamics of films, jets, and drops

    CERN Document Server

    Middleman, Stanley

    1995-01-01

    This concise book is intended to fulfill two purposes: to provide an important supplement to classic texts by carrying fluid dynamics students on into the realm of free boundary flows; and to demonstrate the art of mathematical modeling based on knowledge, intuition, and observation. In the authors words, the overall goal is make the complex simple, without losing the essence--the virtue--of the complexity.Modeling Axisymmetric Flows: Dynamics of Films, Jets, and Drops is the first book to cover the topics of axisymmetric laminar flows; free-boundary flows; and dynamics of drops, jets, and films. The text also features comparisons of models to experiments, and it includes a large selection of problems at the end of each chapter.Key Features* Contains problems at the end of each chapter* Compares real-world experimental data to theory* Provides one of the first comprehensive examinations of axisymmetric laminar flows, free-boundary flows, and dynamics of drops, jets, and films* Includes development of basic eq...

  11. Energy and energy flux in axisymmetric slow and fast waves

    Science.gov (United States)

    Moreels, M. G.; Van Doorsselaere, T.; Grant, S. D. T.; Jess, D. B.; Goossens, M.

    2015-06-01

    Aims: We aim to calculate the kinetic, magnetic, thermal, and total energy densities and the flux of energy in axisymmetric sausage modes. The resulting equations should contain as few parameters as possible to facilitate applicability for different observations. Methods: The background equilibrium is a one-dimensional cylindrical flux tube model with a piecewise constant radial density profile. This enables us to use linearised magnetohydrodynamic equations to calculate the energy densities and the flux of energy for axisymmetric sausage modes. Results: The equations used to calculate the energy densities and the flux of energy in axisymmetric sausage modes depend on the radius of the flux tube, the equilibrium sound and Alfvén speeds, the density of the plasma, the period and phase speed of the wave, and the radial or longitudinal components of the Lagrangian displacement at the flux tube boundary. Approximate relations for limiting cases of propagating slow and fast sausage modes are also obtained. We also obtained the dispersive first-order correction term to the phase speed for both the fundamental slow body mode under coronal conditions and the slow surface mode under photospheric conditions. Appendix A is available in electronic form at http://www.aanda.org

  12. Relay mirror experiment

    Science.gov (United States)

    Begley, David L.

    1996-04-01

    Originating out of a SDIO-funded, Phase 1 study effort, two ground systems and an orbiting EO payload/spacecraft were the primary equipment for the RME. The RME was originally conceived to be a shuttle deployed experiment. Shortly after program start, the Challenger disaster occurred, with the promise of extensive delays. A completely new space segment was to be designed incorporating a free-flying spacecraft. During the midphase of the program, a variety of launch vehicles were envisioned to replace the shuttle, requiring the BASD team to design accommodations for Delta, Atlas, and Titan, with a Delta launch being the final solution. The ground systems tracked the spacecraft and illuminated it with green and blue beacon lasers. The Payload Experiment Package (PEP) housed the bisection tracker, a key innovation central to the experiment. The bisection tracker acquired both beacons and controlled steerable mirrors to accomplish fine tracking of the two cooperative beacons. In the process, the relay mirror was precisely positioned to enable a successful relay of a third infrared laser between the two ground sites via the orbiting spacecraft. Many of the key technologies employed in the PEP were originally developed for Ball laser communications research and development programs and other laser pointing efforts. The WAVE sensor package, built by ATA and integrated by Ball, measured the vibrations of the optical base structure on which it was mounted. These spacecraft vibration data are critical to the accurate pointing of space laser communication terminals.

  13. TCV mirrors cleaned by plasma

    Directory of Open Access Journals (Sweden)

    L. Marot

    2017-08-01

    Full Text Available Metallic mirrors exposed in TCV tokamak were cleaned by plasma in laboratory. A gold (Au mirror was deposited with 185–285nm of amorphous carbon (aC:D film coming from the carbon tiles of TCV. Another molybdenum (Mo mirror had a thicker deposit due to a different location within the tokamak. The thickness measurements were carried out using ellipsometry and the reflectivity measurements performed by spectrophotometry revealed a decrease of the specular reflectivity in the entire range (250–2500nm for the Mo mirror and specifically in the visible spectrum for the Au. Comparison of the simulated reflectivity using a refractive index of 1.5 and a Cauchy model for the aC:D gives good confidence on the estimated film thickness. Plasma cleaning using radio frequency directly applied to a metallic plate where the mirrors were fixed demonstrated the ability to remove the carbon deposits. A mixture of 50% hydrogen and 50% helium was used with a −200V self-bias. Due to the low sputtering yield of He and the low chemical erosion of hydrogen leading to volatile molecules, 20h of cleaning were needed for Au mirror and more than 60h for Mo mirror. Recovery of the reflectivity was not complete for the Au mirror most likely due to damage of the surface during tokamak exposure (breakdown phenomena.

  14. Acoustic Models of Optical Mirrors

    Science.gov (United States)

    Mayer, V. V.; Varaksina, E. I.

    2014-01-01

    Students form a more exact idea of the action of optical mirrors if they can observe the wave field being formed during reflection. For this purpose it is possible to organize model experiments with flexural waves propagating in thin elastic plates. The direct and round edges of the plates are used as models of plane, convex and concave mirrors.…

  15. Negative Reflecting Meta-Mirrors.

    Science.gov (United States)

    Yang, Rui; Li, Dong; Gao, Dongxing; Zhang, Aofang; Hu, Bowei; Yang, Pei; Lei, Zhenya; Li, Jiacheng

    2017-07-18

    Using the gradient phase discontinuities that meta-mirrors provide, we show that the incident wave can be reflected anomalously with a broad angle range of negative reflections. Such reversed behaviors promote the immediate applications for the planar meta-mirrors to steer the signals more arbitrarily and the convex meta-mirrors to focus and collimate electromagnetic fields. We practically implement these negative reflecting meta-mirrors through an arrangement of subwavelength ring patches and generate the desired phase distribution by also considering the incident angle. Finally, the experiments are carried out to verify the functionality of the convex meta-mirror firstly, and the performances of the planar meta-mirror are also tested by further building up a dual reflector system with the demonstration of obtaining the plane wave from the convex meta-mirror and then having the well collimated beam negative reflected by the planar meta-mirror. The proposed design should be readily applicable to a wide range of electromagnetic problems, especially for devising smart planar illusion devices, and highly directive antennas mounting on convex surfaces of various platforms.

  16. Eliminating mirror responses by instructions.

    Science.gov (United States)

    Bardi, Lara; Bundt, Carsten; Notebaert, Wim; Brass, Marcel

    2015-09-01

    The observation of an action leads to the activation of the corresponding motor plan in the observer. This phenomenon of motor resonance has an important role in social interaction, promoting imitation, learning and action understanding. However, mirror responses not always have a positive impact on our behavior. An automatic tendency to imitate others can introduce interference in action execution and non-imitative or opposite responses have an advantage in some contexts. Previous studies suggest that mirror tendencies can be suppressed after extensive practice or in complementary joint action situations revealing that mirror responses are more flexible than previously thought. The aim of the present study was to gain insight into the mechanisms that allow response flexibility of motor mirroring. Here we show that the mere instruction of a counter-imitative mapping changes mirror responses as indexed by motor evoked potentials (MEPs) enhancement induced by transcranial magnetic stimulation (TMS). Importantly, mirror activation was measured while participants were passively watching finger movements, without having the opportunity to execute the task. This result suggests that the implementation of task instructions activates stimulus-response association that can overwrite the mirror representations. Our outcome reveals one of the crucial mechanisms that might allow flexible adjustments of mirror responses in different contexts. The implications of this outcome are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. [Mirror therapy in hemiplegic patient].

    Science.gov (United States)

    Lisalde-Rodríguez, María Elena; Garcia-Fernández, José Antonio

    2016-01-01

    Mirror therapy is a relatively new intervention, every time more used and with easy access for the rehabilitation treatment of stroke patient. The patient moves the unaffected limb in front of a mirror watching the reflection of that move as if he was moving de affected limb. To analyze the effectiveness of mirror therapy in the sensorimotor function, hemineglect and activities of daily living of stroke patients. We defined a strategy of bibliography search in Medline, EMBASE, PEDro y Cochrane Central Register of Controlled Trials (CENTRAL) looking for randomised controlled trials (RCT) conducted with hemiplegic patients considering mirror therapy as the main rehabilitation intervention. Seven trials met the inclusion criteria with medium-high methodological quality. Most of them evaluate the mirror therapy effect on motor outcomes showing significant improvements. Three of this RCTs evaluate the effect of mirror therapy on the hemineglect with positive result. A combination of mirror therapy with conventional rehabilitation obtained significant improvements mainly in motor function but not that much on sensory function and functional performance. About the effect of mirror therapy on hemineglect, there are significant improvements but supported only with a few RCTs with small sample sizes producing promising but inconclusive results.

  18. Mirroring patients – or not

    DEFF Research Database (Denmark)

    Davidsen, Annette Sofie; Fosgerau, Christina Fogtmann

    2015-01-01

    and acoustic features of speech. GPs mirrored their patients more than psychiatrists in all modalities and were more flexible in their interactional behaviour. Psychiatrists seemed more static, regardless of the emotionality displayed by patients. Implicitly mirroring and attuning to patients could signify...

  19. Modification of the Argonne tandem

    International Nuclear Information System (INIS)

    Yntema, J.L.

    1978-01-01

    For nuclear structure experiments with heavy ions it is necessary to have ion energies in excess of 5 MeV per nucleon. At the Argonne tandem FN accelerator this was accomplished by the addition of a superconducting linac. Modifications of the FN tandem to improve the performance of the pair is described

  20. Tandems as injectors for synchrotrons

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1993-01-01

    This is a review on the use of tandem electrostatic accelerators for injection and fitting of synchrotrons to accelerate intense beams of heavy ions to relativistic energies. The paper emphasizes the need of operating the tandems in pulsed mode for this application. It has been experimentally demonstrated that at present this type of accelerator still provides the most reliable and best performance. (orig.)

  1. JAERI tandem-accelerator and tandem-booster

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In 1982, aiming at the new development of atomic energy research, the tandem accelerator of Japan Atomic Energy Research Institute (JAERI) was installed. In fiscal year 1993, the superconducting boosters which can increase the ion energy by up to 4 times were added, and the research in the region below 1000 MeV became possible. Those are electrostatic type accelerators which are easy to be used especially in basic research field, and are useful for future research. The tandem accelerator has been operated while maintaining the first class performance as the accelerator for various kinds of heavy ion beam. It has the special shape among electrostatic type accelerators, and is excellent in the easiness of control and stability. The main particulars of the tandem accelerator are shown. As for the ion sources of the tandem accelerator, three cesium sputter type ion sources are installed on two high voltage stands. The kinds of the ions which can be accelerated are mainly negative ions. As the improvement, electron cyclotron resonance (ECR) ion sources are expected to be adopted. As for the tandem boosters, the 1/4 wavelength type resonance hollow cylinder was adopted. The constitution of the tandem boosters is explained. The way of utilizing the tandem accelerator system and the aim for hereafter are reported. (K.I.)

  2. Tandem accelerator operation

    International Nuclear Information System (INIS)

    Rummel, R.L.; Carter, E.P.; Westerfeldt, C.R.

    1985-01-01

    For the period July 1, 1984 through July 31, 1985 the FN tandem accelerator was operated for 6760 hours. This represents 72% utilization of the maximum available machine time for the past 13 months. The total running time for this machine is now 104,470 hours, and the age of two of the accelerator tubes exceeds 100,000 hours. In August of last year the authors removed the liquid-nitrogen trapped mercury diffusion pump on the low energy end of the accelerator. In its place the authors installed a Varian Cryostack cryopump along with a new NEC beam scanner, a new set of beam chopper plates, and new vacuum gauges and protection circuits. The vacuum in the low energy tube has been improved from 5 x 10 -6 to 5 x 10 -7 Torr

  3. Enzyme catalysed tandem reactions.

    Science.gov (United States)

    Oroz-Guinea, Isabel; García-Junceda, Eduardo

    2013-04-01

    To transfer to the laboratory, the excellent efficiency shown by enzymes in Nature, biocatalysis, had to mimic several synthetic strategies used by the living organisms. Biosynthetic pathways are examples of tandem catalysis and may be assimilated in the biocatalysis field for the use of isolated multi-enzyme systems in the homogeneous phase. The concurrent action of several enzymes that work sequentially presents extraordinary advantages from the synthetic point of view, since it permits a reversible process to become irreversible, to shift the equilibrium reaction in such a way that enantiopure compounds can be obtained from prochiral or racemic substrates, reduce or eliminate problems due to product inhibition or prevent the shortage of substrates by dilution or degradation in the bulk media, etc. In this review we want to illustrate the developments of recent studies involving in vitro multi-enzyme reactions for the synthesis of different classes of organic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Advanced Mirror & Modelling Technology Development

    Science.gov (United States)

    Effinger, Michael; Stahl, H. Philip; Abplanalp, Laura; Maffett, Steven; Egerman, Robert; Eng, Ron; Arnold, William; Mosier, Gary; Blaurock, Carl

    2014-01-01

    The 2020 Decadal technology survey is starting in 2018. Technology on the shelf at that time will help guide selection to future low risk and low cost missions. The Advanced Mirror Technology Development (AMTD) team has identified development priorities based on science goals and engineering requirements for Ultraviolet Optical near-Infrared (UVOIR) missions in order to contribute to the selection process. One key development identified was lightweight mirror fabrication and testing. A monolithic, stacked, deep core mirror was fused and replicated twice to achieve the desired radius of curvature. It was subsequently successfully polished and tested. A recently awarded second phase to the AMTD project will develop larger mirrors to demonstrate the lateral scaling of the deep core mirror technology. Another key development was rapid modeling for the mirror. One model focused on generating optical and structural model results in minutes instead of months. Many variables could be accounted for regarding the core, face plate and back structure details. A portion of a spacecraft model was also developed. The spacecraft model incorporated direct integration to transform optical path difference to Point Spread Function (PSF) and between PSF to modulation transfer function. The second phase to the project will take the results of the rapid mirror modeler and integrate them into the rapid spacecraft modeler.

  5. A high-precision algorithm for axisymmetric flow

    Directory of Open Access Journals (Sweden)

    A. Gokhman

    1995-01-01

    Full Text Available We present a new algorithm for highly accurate computation of axisymmetric potential flow. The principal feature of the algorithm is the use of orthogonal curvilinear coordinates. These coordinates are used to write down the equations and to specify quadrilateral elements following the boundary. In particular, boundary conditions for the Stokes' stream-function are satisfied exactly. The velocity field is determined by differentiating the stream-function. We avoid the use of quadratures in the evaluation of Galerkin integrals, and instead use splining of the boundaries of elements to take the double integrals of the shape functions in closed form. This is very accurate and not time consuming.

  6. Accuracy Improvement in Magnetic Field Modeling for an Axisymmetric Electromagnet

    Science.gov (United States)

    Ilin, Andrew V.; Chang-Diaz, Franklin R.; Gurieva, Yana L.; Il,in, Valery P.

    2000-01-01

    This paper examines the accuracy and calculation speed for the magnetic field computation in an axisymmetric electromagnet. Different numerical techniques, based on an adaptive nonuniform grid, high order finite difference approximations, and semi-analitical calculation of boundary conditions are considered. These techniques are being applied to the modeling of the Variable Specific Impulse Magnetoplasma Rocket. For high-accuracy calculations, a fourth-order scheme offers dramatic advantages over a second order scheme. For complex physical configurations of interest in plasma propulsion, a second-order scheme with nonuniform mesh gives the best results. Also, the relative advantages of various methods are described when the speed of computation is an important consideration.

  7. Modelling Acoustic Wave Propagation in Axisymmetric Varying-Radius Waveguides

    DEFF Research Database (Denmark)

    Bæk, David; Willatzen, Morten

    2008-01-01

    A computationally fast and accurate model (a set of coupled ordinary differential equations) for fluid sound-wave propagation in infinite axisymmetric waveguides of varying radius is proposed. The model accounts for fluid heat conduction and fluid irrotational viscosity. The model problem is solved...... by expanding solutions in terms of cross-sectional eigenfunctions following Stevenson’s method. A transfer matrix can be easily constructed from simple model responses of a given waveguide and later used in computing the response to any complex wave input. Energy losses due to heat conduction and viscous...

  8. Fusion-product transport in axisymmetric tokamaks: losses and thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Hively, L.M.

    1980-01-01

    High-energy fusion-product losses from an axisymmetric tokamak plasma are studied. Prompt-escape loss fluxes (i.e. prior to slowing down) are calculated including the non-separable dependence of flux as a function of poloidal angle and local angle-of-incidence at the first wall. Fusion-product (fp) thermalization and heating are calculated assuming classical slowing down. The present analytical model describes fast ion orbits and their distribution function in realistic, high-..beta.., non-circular tokamak equilibria. First-orbit losses, trapping effects, and slowing-down drifts are also treated.

  9. Stabilized thermally compensated mirror

    International Nuclear Information System (INIS)

    Dunn, C. III; Tobin, R.D.; Bergstreser, N.E.; Heinz, T.A.

    1975-01-01

    A thermally compensated mirror is described that is formed by a laminated structure. The structure is comprised of a front plate having a reflective front surface and having a plurality of grooves formed in the rear surface for conducting coolant fluid in heat exchanging relation with said reflective surface, a rear plate having coolant inlet and coolant outlet openings extending therethrough, a minimum temperature plate interposed between said front and rear plates and formed with a plurality of coolant distribution passageways coupled to receive coolant fluid from said coolant inlet and oriented to distribute said coolant fluid in a manner to establish a minimum temperature plane parallel to said reflective surface, a temperature stabilization plate interposed between said front plate and said minimum temperature plate and formed with a plurality of coolant distribution channels coupled to receive said coolant fluid after said coolant fluid has passed in heat exchanging relation with said reflective surface and oriented to distribute said coolant fluid in a manner to establish a uniform temperature plane parallel to said reflective surface, and means for circulating said coolant fluid through said structure in a predetermined path. (U.S.)

  10. Tinbergen on mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology-the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that the latter provides the defeasible 'best explanation' for current data on the causation and ontogeny of MNs; and to argue that functional analysis, of the kind that Tinbergen identified somewhat misleadingly with studies of 'survival value', should be a high priority for future research. In this kind of functional analysis, system-level theories would assign MNs a small, but potentially important, role in the achievement of action understanding-or another social cognitive function-by a production line of interacting component processes. These theories would be tested by experimental intervention in human and non-human animal samples with carefully documented and controlled developmental histories.

  11. The magic of relay mirrors

    Science.gov (United States)

    Duff, Edward A.; Washburn, Donald C.

    2004-09-01

    Laser weapon systems would be significantly enhanced with the addition of high altitude or space-borne relay mirrors. Such mirrors, operating alone with a directed energy source, or many in a series fashion, can be shown to effectively move the laser source to the last, so-called fighting mirror. This "magically" reduces the range to target and offers to enhance the performance of directed energy systems like the Airborne Laser and even ground-based or ship-based lasers. Recent development of high altitude airships will be shown to provide stationary positions for such relay mirrors thereby enabling many new and important applications for laser weapons. The technical challenges to achieve this capability are discussed.

  12. Reflections on a Black Mirror

    OpenAIRE

    Good, Michael R. R.

    2016-01-01

    A black mirror is an accelerated boundary that produces particles in an exact correspondence to an evaporating black hole. We investigate the spectral dynamics of the particle creation during the formation process.

  13. Identification of multiple modes of axisymmetric or circularly repetitive structures

    International Nuclear Information System (INIS)

    Kopff, P.

    1983-01-01

    The axisymmetric structures, or those composed with circularly repetitive elements, often display multiple modes, which are not easy to separate by modal identification of experimental responses. To be able to solve in situ some problems related to the vibrational behaviour of reactor vessels or other such huge structures, ELECTRICITY DE FRANCE developed a few years ago, experimental capabilities providing heavy harmonic driving forces, and elaborate data acquisition, signal processing and modal identification software, self-contained in an integrated mobile test facility. The modal analysis techniques we have developed with the LABORATOIRE DE MECANIQUE Appliquee of University of BESANCON (FRANCE) were especially suited for identification of multiple or separation of quasi-multiple modes, i.e. very close and strongly coupled resonances. Besides, the curve fitting methods involved, compute the same complex eigen-frequencies for all the vibration pick-ups, for better accuracy of the related eigen-vector components. Moreover, the latest extensions of these algorithms give us the means to deal with non-linear behaviour. The performances of these programs are drawn from some experimental results on axisymmetric or circularly repetitive structure, we tested in our laboratory to validate the computational hypothesis used in models for seismic responses of breeder reactor vessels. (orig.)

  14. Elastic layer under axisymmetric indentation and surface energy effects

    Science.gov (United States)

    Intarit, Pong-in; Senjuntichai, Teerapong; Rungamornrat, Jaroon

    2018-04-01

    In this paper, a continuum-based approach is adopted to investigate the contact problem of an elastic layer with finite thickness and rigid base subjected to axisymmetric indentation with the consideration of surface energy effects. A complete Gurtin-Murdoch surface elasticity is employed to consider the influence of surface stresses. The indentation problem of a rigid frictionless punch with arbitrary axisymmetric profiles is formulated by employing the displacement Green's functions, derived with the aid of Hankel integral transform technique. The problem is solved by assuming the contact pressure distribution in terms of a linear combination of admissible functions and undetermined coefficients. Those coefficients are then obtained by employing a collocation technique and an efficient numerical quadrature scheme. The accuracy of proposed solution technique is verified by comparing with existing solutions for rigid indentation on an elastic half-space. Selected numerical results for the indenters with flat-ended cylindrical and paraboloidal punch profiles are presented to portray the influence of surface energy effects on elastic fields of the finite layer. It is found that the presence of surface stresses renders the layer stiffer, and the size-dependent behavior of elastic fields is observed in the present solutions. In addition, the surface energy effects become more pronounced with smaller contact area; thus, the influence of surface energy cannot be ignored in the analysis of indentation problem especially when the indenter size is very small such as in the case of nanoindentation.

  15. Aerodynamics characteristic of axisymmetric surface protuberance in supersonic regime

    KAUST Repository

    Qamar, Adnan

    2012-01-01

    The present work deals with the problem of an axi-symmetric surface protuberance mounted on a spherical nosed body of revolution. The numerical computations are carried out for laminar supersonic viscous flow for trapezoidal shape axi-symmetric protuberances. A free stream Mach number ranging from 3 to 8 in steps of 1 at a fixed free stream Reynolds number of 1.8x10(4) has been used in the present study. The steady solutions are obtained using a time marching approach. A newly developed Particle Velocity Upwinding (PVU) scheme has been used for the computation. The spatial flow pattern exhibits a strong bow shock in front of the hemispherical nose, which engulfs the entire base body. Near the protuberance, the fluid particle decelerates due to the adverse pressure created by the protuberance and thus the flow separates in front of the protuberance. This point of separation is found to be a function of Mach number and the protuberance shape. A low-pressure expansion region dominates the base region of the obstacle. The reattachment point for the base separation is also a function of Mach number. As the Mach number is increased the reattachment point shifts toward the protuberances base. A weak recompression shock is also seen in the base, which affects the separated zone behind the protuberance. The important design parameters such as skin friction, heat transfer, drag, and surface pressure coefficients are reported extensively.

  16. Stress analysis in a non axisymmetric loaded reactor pressure vessel

    International Nuclear Information System (INIS)

    Albuquerque, Levi Barcelos; Assis, Gracia Menezes V. de; Miranda, Carlos Alexandre J.; Cruz, Julio Ricardo B.; Mattar Neto, Miguel

    1995-01-01

    In this work we intend to present the stress analysis of a PWR vessel under postulated concentrated loads. The vessel was modeled with Axisymmetric solid 4 nodes harmonic finite elements with the use of the ANSYS program, version 5.0. The bolts connecting the vessel flanges were modeled with beam elements. Some considerations were made to model the contact between the flanges. The perforated part of the vessel tori spherical head was modeled (with reduced properties due to its holes) to introduce its stiffness and loads but was not within the scope of this work. The loading consists of some usual ones, as pressure, dead weight, bolts preload, seismic load and some postulated ones as concentrated loads, over the vessel, modeled by Fourier Series. The results in the axisymmetric model are taken in terms of linearized stresses, obtained in some circumferential positions and for each position, in some sections along the vessel. Using the ASME Code (Section III, Division 1, Sub-section NB) the stresses are within the allowable limits. In order to draw some conclusions about stress linearization, the membrane plus bending stresses (Pl + Pb) are obtained and compared in some sections, using three different methods. (author)

  17. Uncertainty evaluation method for axi-symmetric measurement machines

    Directory of Open Access Journals (Sweden)

    Muelaner Jody Emlyn

    2016-01-01

    Full Text Available This paper describes a method of uncertainty evaluation for axi-symmetric measurement machines. Specialized measuring machines for the inspection of axisymmetric components enable the measurement of properties such as roundness (radial runout, axial runout and coning. These machines typically consist of a rotary table and a number of contact measurement probes located on slideways. Sources of uncertainty include the probe calibration process, probe repeatability, probe alignment, geometric errors in the rotary table, the dimensional stability of the structure holding the probes and form errors in the reference hemisphere which is used to calibrate the system. The generic method is described and an evaluation of an industrial machine is described as a worked example. Expanded uncertainties, at 95% confidence, were then calculated for the measurement of; radial runout (1.2 μm with a plunger probe or 1.7 μm with a lever probe; axial runout (1.2 μm with a plunger probe or 1.5 μm with a lever probe; and coning/swash (0.44 arcseconds with a plunger probe or 0.60 arcseconds with a lever probe.

  18. Hot Wire Measurements in a Axisymmetric Shear Layer with Swirl

    Science.gov (United States)

    Ewing, D.; Pollard, A.

    1996-11-01

    It is well known that the introduction of swirl in an axisymmetric jet can influence the development of and mixing in the near field of the jet. Recent efforts to compute this flow have demonstrated that the development of the near field is dependent on parameters at the jet outlet other than distribution of the swirl component, such as the distribution the mean radial velocity (Xai, J.L., Smith, B.L., Benim, A. C., Schmidli, J., and Yadigaroglu, G. (1996) Influence of Boundary Conditions on Swirling Flow in Combustors, Proc. ASME Fluid. Eng. Div. Summer Meeting), San Diego, Ca., July 7-11.. An experimental rig has been designed to produce co-axial round and annular swirling jets with uniform outlet conditions in each flow. The flow rate and swirl component from each of these jets can be controlled independently and the rig can be configured to produce both co- and counter-swirling flows. Thus, the rig can be used to carry out an extensive investigation of the effect of swirl on the development of axisymmetric flows. The key design features of the rig and the first sets of hot-wire measurements in the shear layer will be reported here.

  19. Mirror Neurons from Associative Learning

    OpenAIRE

    Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2016-01-01

    Mirror neurons fire both when executing actions and observing others perform similar actions. Their sensorimotor matching properties have generally been considered a genetic adaptation for social cognition; however, in the present chapter we argue that the evidence in favor of this account is not compelling. Instead we present evidence supporting an alternative account: that mirror neurons’ matching properties arise from associative learning during individual development. Notably, this proces...

  20. [Ballantyne syndrome or mirror syndrome].

    Science.gov (United States)

    Torres-Gómez, Luis Guillermo; Silva-González, María Eugenia; González-Hernández, Rigoberto

    2010-11-01

    Ballantyne syndrome or mirror syndrome is a triad consisting of the presence of fetal hydrops, generalized edema placentomegaly mother. May be related to any cause of fetal hydrops. The fetal prognosis is poor in untreated cases, the mother has reference to be the cause or the termination of pregnancy. Present the case of a 26-year-old who developed mirror syndrome secondary to non-immune fetal hydrops of unknown origin, accompanied by preeclampsia.

  1. Effect of teaching with or without mirror on balance in young female ballet students

    Science.gov (United States)

    2014-01-01

    Background In literature there is a general consensus that the use of the mirror improves proprioception. During rehabilitation the mirror is an important instrument to improve stability. In some sports, such as dancing, mirrors are widely used during training. The purpose of this study is to evaluate the effectiveness of the use of a mirror on balance in young dancers. Sixty-four young dancers (ranging from 9–10 years) were included in this study. Thirty-two attending lessons with a mirror (mirror- group) were compared to 32 young dancers that attended the same lessons without a mirror (non-mirror group). Balance was evaluated by BESS (Balance Error Scoring System), which consists of three stances (double limb, single limb, and tandem) on two surfaces (firm and foam). The errors were assessed at each stance and summed to create the two subtotal scores (firm and foam surface) and the final total score (BESS). The BESS was performed at recruitment (T0) and after 6 months of dance lessons (T1). Results The repeated measures ANOVA analysis showed that for the BESS total score there is a difference due to the time (F = 3.86; p  0.05). The analysis of the multiple regression model showed the influence of the values at T0 for every BESS items and the dominance of limb for stability on an unstable surface standing on one or two legs. Conclusions These preliminary results suggest that the use of a mirror in a ballet classroom does not improve balance acquisition of the dancer. On the other hand, improvement found after 6 months confirms that at the age of the dancers studied motor skills and balance can easily be trained and improved. PMID:24996519

  2. Tandem Van de Graaff facility

    Data.gov (United States)

    Federal Laboratory Consortium — Completed in 1970, the Tandem Van de Graaff facility was for many years the world's largest electrostatic accelerator facility. It can provide researchers with beams...

  3. Superconducting linacs used with tandems

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    1984-01-01

    The main features of superconducting linacs used as post-accelerators of tandems are reviewed. Various aspects of resonators, cryogenics and electronics are discussed, and recent advances in the field are presented. (orig.)

  4. EAGLE: relay mirror technology development

    Science.gov (United States)

    Hartman, Mary; Restaino, Sergio R.; Baker, Jeffrey T.; Payne, Don M.; Bukley, Jerry W.

    2002-06-01

    EAGLE (Evolutionary Air & Space Global Laser Engagement) is the proposed high power weapon system with a high power laser source, a relay mirror constellation, and the necessary ground and communications links. The relay mirror itself will be a satellite composed of two optically-coupled telescopes/mirrors used to redirect laser energy from ground, air, or space based laser sources to distant points on the earth or space. The receiver telescope captures the incoming energy, relays it through an optical system that cleans up the beam, then a separate transmitter telescope/mirror redirects the laser energy at the desired target. Not only is it a key component in extending the range of DoD's current laser weapon systems, it also enables ancillary missions. Furthermore, if the vacuum of space is utilized, then the atmospheric effects on the laser beam propagation will be greatly attenuated. Finally, several critical technologies are being developed to make the EAGLE/Relay Mirror concept a reality, and the Relay Mirror Technology Development Program was set up to address them. This paper will discuss each critical technology, the current state of the work, and the future implications of this program.

  5. Directly polished lightweight aluminum mirror

    Science.gov (United States)

    ter Horst, Rik; Tromp, Niels; de Haan, Menno; Navarro, Ramon; Venema, Lars; Pragt, Johan

    2017-11-01

    During the last ten years, Astron has been a major contractor for the design and manufacturing of astronomical instruments for Space- and Earth based observatories, such as VISIR, MIDI, SPIFFI, X-Shooter and MIRI. Driven by the need to reduce the weight of optically ultra-stiff structures, two promising techniques have been developed in the last years: ASTRON Extreme Lightweighting [1][2] for mechanical structures and an improved Polishing Technique for Aluminum Mirrors. Using one single material for both optical components and mechanical structure simplifies the design of a cryogenic instrument significantly, it is very beneficial during instrument test and verification, and makes the instrument insensitive to temperature changes. Aluminum has been the main material used for cryogenic optical instruments, and optical aluminum mirrors are generally diamond turned. The application of a polishable hard top coating like nickel removes excess stray light caused by the groove pattern, but limits the degree of lightweighting of the mirrors due to the bi-metal effect. By directly polishing the aluminum mirror surface, the recent developments at Astron allow for using a non-exotic material for light weighted yet accurate optical mirrors, with a lower surface roughness ( 1nm RMS), higher surface accuracy and reduced light scattering. This paper presents the techniques, obtained results and a global comparison with alternative lightweight mirror solutions. Recent discussions indicate possible extensions of the extreme light weight technology to alternative materials such as Zerodur or Silicon Carbide.

  6. Advances in telescope mirror cleaning

    Science.gov (United States)

    Blanken, Maarten F.; Chopping, Alan K.; Dee, Kevin M.

    2004-09-01

    Metrology and cleaning techniques for telescope mirrors are generally well established. CO2 cleaning and water washing are mainly used. Water washing has proven to be the best method of removing oil and water stains and restoring the aluminium to nearly fresh values. The risk of water getting to unwanted places such as electronics or other optics prevents this method from being employed more often. Recently the Isaac Newton Group introduced a new cleaning technique for their telescope mirrors, which reduces the risks discussed above. This technique uses water vapour instead of water to wash the mirror. The advantage of this method is that the amount of water needed is drastically reduced. In addition the pressure of the vapour will blow away any large dust particles on the mirror and the temperature shock between the vapour and the mirror will help to de-bond the dust particles. Adding a soapy solution will help to clean oil and watermarks of the mirror. This paper describes the vapour cleaning method, tests that have been done and the overall findings.

  7. Topological Fluid Mechanics with Applications to Free Surfaces and Axisymmetric Flows

    DEFF Research Database (Denmark)

    Brøns, Morten

    1996-01-01

    Topological fluid mechanics is the study of qualitative features of fluid patterns. We discuss applications to the flow beneath a stagnant surface film, and to patterns in axisymmetric flow.......Topological fluid mechanics is the study of qualitative features of fluid patterns. We discuss applications to the flow beneath a stagnant surface film, and to patterns in axisymmetric flow....

  8. Proposed Lucas Heights tandem accelerator

    International Nuclear Information System (INIS)

    1985-01-01

    An 8 million volt tandem accelerator (LHTA - Lucas Heights Tandem Accelerator) is proposed to be installed at the Australian Atomic Energy Commission's Lucas Heights Research Laboratories. The new facility is expected to cost $6 million and will have applications such as ultrasensitive trace element analysis for management of groundwater resources, salinity in soil, soil erosion and Antarctic research. Applied physics applications include nuclear safeguards, energy sources, study of material surfaces, archaeology, archaeometry and occupational health

  9. Tandem Terminal Ion Source

    International Nuclear Information System (INIS)

    None

    2000-01-01

    OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the(sup 7)Be((gamma))(sup 8)B experiment. Most of the runs used(sup 1)H(sup+) at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used(sup 2)H(sup+) at terminal voltage of 1.4 MV. The other run used(sup 4)He(sup+) at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal

  10. Laser damage investigations of Cu mirrors

    International Nuclear Information System (INIS)

    Gorshkov, A.; Bel'bas, I.; Maslov, M.; Sannikov, V.; Vukolov, K.

    2005-01-01

    Laser tests were performed on Cu mirrors as 'first mirror' prototypes for laser diagnostics. Data on laser damage thresholds of surfaces under the influence of pulsed YAG laser radiation were obtained for single shot and after about 1.5 x 10 5 shots. The experiments were carried out using three types of copper mirrors: diamond-turned mirror, diamond-turned substrate with copper coating and reflection grating on a copper coated mirror. The lifetime of the copper mirrors was tested. Diffusion scattering was used as a monitor of mirror surface quality. The degradation of diamond turned copper mirrors in multiple pulse laser irradiation appears to be in satisfactory accordance with a model for multipulse laser damage of metal mirrors up to 1.5 x 10 5 laser pulses. The degradation of copper coated mirrors has a more complicated behaviour

  11. On the heat transfer of enhancement condensation of vapor over the surface of an axisymmetric cylinder

    International Nuclear Information System (INIS)

    Xiou, W.J.; Ru, Y.A.; Mo, C.S.; Yi, H.S.

    1987-01-01

    The heat transfer of enhancement condensation of the vapor over the surface of an axisymmetric cylinder has been first studied theoretically in this paper. The problems of an axisymmetric cylinder are transformed into plate problems. The effects of some parameters on heat transfer coefficients of the vapor condensation over the surface of an axisymmetric cylinder have been discussed here. The heat transfer of the vapor condensation over an elliptical cylinder and an axisymmetric wing-shape cylinder has compared with the heat transfer of the vapor condensation over a tube surface. The conclusion is that the heat transfer of the vapor condensation over an elliptical cylinder and an axisymmetric wing-shape cylinder is greater than that over tubes

  12. Tandem Cylinder Noise Predictions

    Science.gov (United States)

    Lockard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  13. Mirror deformation versus contact area in mounted flat mirrors

    Science.gov (United States)

    Clark, James H., III; Penado, F. Ernesto; Cornelius, Frank

    2009-08-01

    Surface flatness of 6-inch diameter mirrors at the Navy Prototype Optical Interferometer is specified to be within 32 nanometers over a 5.4-inch diameter circle centered on the mirror. The current mounting technique is to use three spring plungers applied to the back surface of the mirror, near the perimeter edge, thereby pressing the front surface against three small diameter Teflon pads directly opposite the plungers. The pads have the effect of dissipating the deformation effects within the 5.4-inch diameter region. This paper describes the effects of varying the size of the pads, from a 7/32 inch diameter pad to a point-type contact such as a ball bearing. Experimental results using a phase shifting interferometer are presented, as well as finite element analysis results.

  14. More questions for mirror neurons.

    Science.gov (United States)

    Borg, Emma

    2013-09-01

    The mirror neuron system is widely held to provide direct access to the motor goals of others. This paper critically investigates this idea, focusing on the so-called 'intentional worry'. I explore two answers to the intentional worry: first that the worry is premised on too limited an understanding of mirror neuron behaviour (Sections 2 and 3), second that the appeal made to mirror neurons can be refined in such a way as to avoid the worry (Section 4). I argue that the first response requires an account of the mechanism by which small-scale gestures are supposedly mapped to larger chains of actions but that none of the extant accounts of this mechanism are plausible. Section 4 then briefly examines refinements of the mirror neuron-mindreading hypothesis which avoid the intentional worry. I conclude that these refinements may well be plausible but that they undermine many of the claims standardly made for mirror neurons. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Gasdynamic Multiple-Mirror Trap

    Science.gov (United States)

    Beklemishev, Alexei; Anikeev, Andrei; Bagryansky, Peter; Burdakov, Alexander; Gavrilenko, Dmitrii; Ivanov, Alexander; Polosatkin, Sergei; Sinitsky, Stanislav

    2013-10-01

    The new linear device for confinement of fusion plasmas, GDMT, is being developed at the Budker Institute of Nuclear Physics, Novosibirsk. The facility will combine features of existing GOL-3 and GDT devices: the central GDT-like cell with sloshing NBI ions, and the multiple-mirror plugs for suppression of axial losses. Such combination became feasible due to recent discoveries. In particular, the requirement of flute-mode stability can be relaxed by using vortex confinement, achieved by plasma biasing through open field lines. This allows the use of potentially destabilizing multiple-mirror sections. Another key effect is the enhanced multiple-mirror confinement at low densities, which is due to collective rather than coulomb scattering of ions. Hence the multiple-mirror plugs can work at pressures compatible with magnetic confinement. These two main technologies are supplemented by axial injection of pulsed electron beams. Besides additional plasma heating (like in GOL-3), such injection can be used for induced collective scattering in the multiple-mirror plugs and for plasma biasing. The new device is designed to be superconducting and modular. It will be built in stages, with the first stage, GDMT-T, intended for PMI studies. The work was financially supported by Ministry of Education and Science RF.

  16. Metamaterial mirrors in optoelectronic devices

    KAUST Repository

    Esfandyarpour, Majid

    2014-06-22

    The phase reversal that occurs when light is reflected from a metallic mirror produces a standing wave with reduced intensity near the reflective surface. This effect is highly undesirable in optoelectronic devices that use metal films as both electrical contacts and optical mirrors, because it dictates a minimum spacing between the metal and the underlying active semiconductor layers, therefore posing a fundamental limit to the overall thickness of the device. Here, we show that this challenge can be circumvented by using a metamaterial mirror whose reflection phase is tunable from that of a perfect electric mirror († = €) to that of a perfect magnetic mirror († = 0). This tunability in reflection phase can also be exploited to optimize the standing wave profile in planar devices to maximize light-matter interaction. Specifically, we show that light absorption and photocurrent generation in a sub-100 nm active semiconductor layer of a model solar cell can be enhanced by ∼20% over a broad spectral band. © 2014 Macmillan Publishers Limited.

  17. Vertex algebras and mirror symmetry

    International Nuclear Information System (INIS)

    Borisov, L.A.

    2001-01-01

    Mirror Symmetry for Calabi-Yau hypersurfaces in toric varieties is by now well established. However, previous approaches to it did not uncover the underlying reason for mirror varieties to be mirror. We are able to calculate explicitly vertex algebras that correspond to holomorphic parts of A and B models of Calabi-Yau hypersurfaces and complete intersections in toric varieties. We establish the relation between these vertex algebras for mirror Calabi-Yau manifolds. This should eventually allow us to rewrite the whole story of toric mirror symmetry in the language of sheaves of vertex algebras. Our approach is purely algebraic and involves simple techniques from toric geometry and homological algebra, as well as some basic results of the theory of vertex algebras. Ideas of this paper may also be useful in other problems related to maps from curves to algebraic varieties.This paper could also be of interest to physicists, because it contains explicit description of holomorphic parts of A and B models of Calabi-Yau hypersurfaces and complete intersections in terms of free bosons and fermions. (orig.)

  18. Axisymmetric Tornado Simulations with a Semi-Slip Boundary

    Directory of Open Access Journals (Sweden)

    Brian H. Fiedler

    2017-12-01

    Full Text Available The structure of natural tornadoes and simulated analogs are sensitive to the lower boundary condition for friction. Three-dimensional numerical simulations of storms require a choice for turbulence parameterizations and resolution of wind near the lower boundary. This article explores some of the consequences of choices of a surface drag coefficient on the structure of a mature simulated tornado, using a conventional axisymmetric model. The surface drag parameterization is explored over the range of the semi-slip condition, including the extremes of no-slip and free-slip. A moderate semi-slip condition allows for an extreme pressure deficit, but without the unrealistic vortex breakdown of the no-slip condition.

  19. Cellular blebs: pressure-driven, axisymmetric, membrane protrusions

    KAUST Repository

    Woolley, Thomas E.

    2013-07-16

    Blebs are cellular protrusions that are used by cells for multiple purposes including locomotion. A mechanical model for the problem of pressure-driven blebs based on force and moment balances of an axisymmetric shell model is proposed. The formation of a bleb is initiated by weakening the shell over a small region, and the deformation of the cellular membrane from the cortex is obtained during inflation. However, simply weakening the shell leads to an area increase of more than 4 %, which is physically unrealistic. Thus, the model is extended to include a reconfiguration process that allows large blebs to form with small increases in area. It is observed that both geometric and biomechanical constraints are important in this process. In particular, it is shown that although blebs are driven by a pressure difference across the cellular membrane, it is not the limiting factor in determining bleb size. © 2013 Springer-Verlag Berlin Heidelberg.

  20. Numerical calculation of axisymmetric non-neutral plasma equilibria

    Science.gov (United States)

    Spencer, Ross L.; Rasband, S. N.; Vanfleet, Richard R.

    1993-12-01

    Efficient techniques for computing axisymmetric non-neutral plasma equilibria are described. These equilibria may be obtained either by requiring global thermal equilibrium, by specifying the midplane radial density profile, or by specifying the radial profile of ∫n dz. Both splines and finite-differences are used, and the accuracy of the two is compared by using a new characterization of the thermal equilibrium density profile which gives a simple formula for estimating the radial and axial gradient scale lengths of thermal equilibria. It is found that for global thermal equilibrium 1% accuracy is achieved with splines if the distance between neighboring splines is about two Debye lengths while finite differences require a grid spacing of about one-half Debye length to achieve the same accuracy.

  1. Energetic Particle Transport in Compact Quasi-axisymmetric Stellarators

    International Nuclear Information System (INIS)

    Redi, M.H.; Mynick, H.E.; Suewattana, M.; White, R.B.; Zarnstorff, M.C.; Isaev, M.Yu.; Mikhailov, M.I.; Subbotin, A.A.

    1999-01-01

    Hamiltonian coordinate, guiding-center code calculations of the confinement of suprathermal ions in quasi-axisymmetric stellarator (QAS) designs have been carried out to evaluate the attractiveness of compact configurations which are optimized for ballooning stability. A new stellarator particle-following code is used to predict ion loss rates and particle confinement for thermal and neutral beam ions in a small experiment with R = 145 cm, B = 1-2 T and for alpha particles in a reactor-size device. In contrast to tokamaks, it is found that high edge poloidal flux has limited value in improving ion confinement in QAS, since collisional pitch-angle scattering drives ions into ripple wells and stochastic field regions, where they are quickly lost. The necessity for reduced stellarator ripple fields is emphasized. The high neutral beam ion loss predicted for these configurations suggests that more interesting physics could be explored with an experiment of less constrained size and magnetic field geometry

  2. Flow in axisymmetric expansion in a catalytic converter

    DEFF Research Database (Denmark)

    Gotfredsen, Erik; Meyer, Knud Erik

    The flow in an axisymmetric expansion (circular diffusor) is used in many different engineering applications, such as heat exchangers, catalytic converters and filters. These applications require a relatively uniform flow at the inlet. To minimise the pressure loss, an ideal solution would...... for a specific local flow rate and a non-uniform inflow to the catalyst will severely reduce the efficiency of the process. Since each ship will have a unique design the flow system, it is desirable to be able to design the system using Computational Fluid Dynamics (CFD). However, CFD fails to predict flow......-scaled model of the catalytic converter is constructed, see figure 1. The experiments are performed at laboratory conditions, with lower pressure, temperature and velocity than the full-scale catalytic converter. The Reynolds number based on the velocity in the inlet pipe and the diameter of the converter...

  3. Ideal, steady-state, axisymmetric magnetohydrodynamic equations with flow

    International Nuclear Information System (INIS)

    Baransky, Y.A.

    1987-01-01

    The motivation of this study is to gain additional understanding of the effect of rotation on the equilibrium of a plasma. The axisymmetric equilibria of ideal magnetohydrodynamics (MHD) with flow have been studied numerically and analytically. A general discussion is provided of previous work on plasmas with flow and comparisons are made to the static model. A variational principle has been derived for the two dimensional problem with comments as to appropriate boundary conditions. An inverse aspect ratio expansion has been used for a study of the toroidal flow equation for both low- and high-β. The inverse aspect ratio expansion has also been used for a study of equations with both poloidal and toroidal flow. An overview is provided of the adaptive finite-difference code which was developed to solve the full equations. (FI)

  4. Pressure drop coefficient of laminar Newtonian flow in axisymmetric diffusers

    International Nuclear Information System (INIS)

    Rosa, S.; Pinho, F.T.

    2006-01-01

    The laminar flow of Newtonian fluids in axisymmetric diffusers has been numerically investigated to evaluate the pressure-loss coefficient as a function of Reynolds number, diffusion angle and expansion ratio. The numerical simulations were carried out with a finite-volume based code using non-orthogonal collocated grids and second order accurate differencing schemes to discretize all terms of the transport equations. The calculations were carried out for Reynolds numbers between 2 and 200, diffusion angles from 0 deg. to 90 deg. and expansion ratios of 1.5 and 2 and the data are presented in tabular form and as correlations. A simplified 1D theoretical analysis helped explain the various contributions to the loss coefficient and its difference relative to the reversible pressure variation due to differences between the actual and fully developed friction losses, distortions of the velocity profiles and pressure non-uniformity upstream and downstream of the expansion section

  5. Secular instability of axisymmetric rotating stars to gravitational radiation reaction

    International Nuclear Information System (INIS)

    Managan, R.A.

    1985-01-01

    A generalization of the Eulerian variational principle derived by Ipser and Managan, for nonaxisymmetric neutral modes of axisymmetric fluid configurations, is developed. The principle provides a variational basis for calculating the frequencies of nonaxisymmetric normal modes proportional to e/sup i/(sigmat + mphi). A modified form of this principle, valid for sigma near 0, is also developed. The latter principle is used to locate the points where the frequency of a nonaxisymmetric normal mode of an axisymmetric rotating fluid configuration passes through zero. lt is at these points that the configuration becomes secularly unstable to gravitational radiation reaction (GRR). This is demonstrated directly by including the GRR potential and showing that the imaginary part of sigma passes through zero and becomes negative at these points. The imaginary part of the frequency is used to estimate the e-folding time of the mode. This variational principle is applied to sequences of rotating polytropes. The sequences are constructed using four rotation laws at each value of the polytropic index n = 0.5, 1.0, 1.5, 2.0, and 3.0. The values of (T/W)/sub m/, the ratio of the rotational kinetic energy to the magnitude of the gravitational potential energy at the onset of instability, and timescales for the modes with m = 2, 3, and 4 are estimated for each sequence. The value of (T/W) 2 is largely independent of the equation of state and rotation law. For m > 2, (T/W)/sub m/ decreases as the equation of state becomes softer, i.e., as the polytropic index n increases, and increases as the amount of differential rotation increases. The most striking result of this behavior occurs for uniform rotation

  6. Thin circular cylinder under axisymmetrical thermal and mechanical loading

    International Nuclear Information System (INIS)

    Arnaudeau, F.; Zarka, J.; Gerij, J.

    1977-01-01

    To assess structural integrity of components subjected to cyclic thermal loadings one must look at thermal ratchetting as a possible failure mode. Considering a thin circular cylinder subjected to constant internal pressure and cyclically varying thermal gradient through the thickness Bree, J. Strain Analysis 2 (1967) No.3, obtained a diagram that serves as a foundation for many design rules (e.g.: ASME code). The upper part of the french LMFBR main vessel is subjected to an axisymmetrical axial thermal loading and an axial load (own weight). Operation of the reactor leads to cyclic variations of the axial thermal loading. The question that arises is whether or not the Bree diagram is realistic for such loading conditions. A special purpose computer code (Ratch) was developed to analyse a thin circular cylinder subjected to axisymmetrical mechanical and thermal loadings. The Mendelson's approach of this problem is followed. Classical Kirchoff-Love hypothesis of thin shells is used and a state of plane stress is assumed. Space integrations are performed by Gaussian quadrature in the axial direction and by Simpson's one third rule throughout the thickness. Thermoelastic-plastic constitutive equations are solved with an implicit scheme (Nguyen). Thermovisco-plastic constitutive equations are solved with an explicit time integration scheme (Treanor's algorithm especially fitted). A Bree type diagram is obtained for an axial step of temperature which varies cyclically and a sustained constant axial load. The material behavior is assumed perfectly plastic and creep effect is not considered. Results show that the domain where no ratchetting occurs is reduced when compared with the domain predicted by the Bree diagram

  7. The relation between mirror self-image reactions and imitation in 14- and 18-month-old infants.

    Science.gov (United States)

    Zmyj, Norbert; Prinz, Wolfgang; Daum, Moritz M

    2013-12-01

    Previous research suggests that sensitivity to aspects of the self and others develop in tandem. We tested 14- and 18-month-olds' imitative abilities and mirror self-image reactions (i.e., testing behavior and passing the mark test). Results showed that 14-month-olds' imitation was closely related to the occurrence of testing behavior in front of the mirror, where they checked whether they could control the movements of the mirror image. Eighteen-month-olds, however, no longer showed this relation. Furthermore, in 18-month-olds, we found a high association between imitation and passing the mark test. These correlations suggest that infants' mirror self-image reactions and imitation share the ability to detect and produce visual-motor contingencies. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Harmonic Distortion in CMOS Current Mirrors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1998-01-01

    One of the origins of harmonic distortion in CMOS current mirrors is the inevitable mismatch between the MOS transistors involved. In this paper we examine both single current mirrors and complementary class AB current mirrors and develop an analytical model for the mismatch induced harmonic...... distortion. This analytical model is verified through simulations and is used for a discussion of the impact of mismatch on harmonic distortion properties of CMOS current mirrors. It is found that distortion levels somewhat below 1% can be attained by carefully matching the mirror transistors but ultra low...... distortion is not achievable with CMOS current mirrors...

  9. Composite single crystal silicon scan mirror substrates, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Single crystal silicon is a desirable mirror substrate for scan mirrors in space telescopes. As diameters of mirrors become larger, existing manufacturing...

  10. Development of ATHENA mirror modules

    DEFF Research Database (Denmark)

    Collon, Maximilien J.; Vacanti, Giuseppe; Barrière, Nicolas M.

    2017-01-01

    Silicon Pore Optics (SPO), developed at cosine with the European Space Agency (ESA) and several academic and industrial partners, provides lightweight, yet stiff, high-resolution X-ray optics. This technology enables ATHENA to reach an unprecedentedly large effective area in the 0.2-12 keV band...... with an angular resolution better than 5". After developing the technology for 50 m and 20 m focal length, this year has witnessed the first 12 m focal length mirror modules being produced. The technology development is also gaining momentum with three different radii under study: Mirror modules for the inner...

  11. Partial Fourier analysis of time-harmonic Maxwell's equations in axisymmetric domains

    International Nuclear Information System (INIS)

    Nkemzi, Boniface

    2003-01-01

    We analyze the Fourier method for treating time-harmonic Maxwell's equations in three-dimensional axisymmetric domains with non-axisymmetric data. The Fourier method reduces the three-dimensional boundary value problem to a system of decoupled two-dimensional boundary value problems on the plane meridian domain of the axisymmetric domain. The reduction process is fully described and suitable weighted spaces are introduced on the meridian domain to characterize the two-dimensional solutions. In particular, existence and uniqueness of solutions of the two-dimensional problems is proved and a priori estimates for the solutions are given. (author)

  12. Axisymmetric thermoviscoelastoplastic state of branched laminar shells, taking account of transverse-shear and torsional deformation

    International Nuclear Information System (INIS)

    Galishin, A.Z.

    1995-01-01

    The nonaxisymmetric thermoelastic stress-strain state (SSS) of branched laminar orthotropic shells was considered; the axisymmetric thermoviscoelastic SSS of branched laminar orthotropic shells was considered; and the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells was considered, taking into account of the transverse-shear deformation. In the present work, in contrast, the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells is considered, taking account of transverse-shear and torsional deformation. Layers that are made from orthotropic materials and deform in the elastic region may be present

  13. Determination of two dimensional axisymmetric finite element model for reactor coolant piping nozzles

    International Nuclear Information System (INIS)

    Choi, S. N.; Kim, H. N.; Jang, K. S.; Kim, H. J.

    2000-01-01

    The purpose of this paper is to determine a two dimensional axisymmetric model through a comparative study between a three dimensional and an axisymmetric finite element analysis of the reactor coolant piping nozzle subject to internal pressure. The finite element analysis results show that the stress adopting the axisymmetric model with the radius of equivalent spherical vessel are well agree with that adopting the three dimensional model. The radii of equivalent spherical vessel are 3.5 times and 7.3 times of the radius of the reactor coolant piping for the safety injection nozzle and for the residual heat removal nozzle, respectively

  14. Timecourse of mirror and counter-mirror effects measured with transcranial magnetic stimulation.

    Science.gov (United States)

    Cavallo, Andrea; Heyes, Cecilia; Becchio, Cristina; Bird, Geoffrey; Catmur, Caroline

    2014-08-01

    The human mirror system has been the subject of much research over the past two decades, but little is known about the timecourse of mirror responses. In addition, it is unclear whether mirror and counter-mirror effects follow the same timecourse. We used single-pulse transcranial magnetic stimulation to investigate the timecourse of mirror and counter-mirror responses in the human brain. Experiment 1 demonstrated that mirror responses can be measured from around 200 ms after observed action onset. Experiment 2 demonstrated significant effects of counter-mirror sensorimotor training at all timepoints at which a mirror response was found in Experiment 1 (i.e. from 200 ms onward), indicating that mirror and counter-mirror responses follow the same timecourse. By suggesting similarly direct routes for mirror and counter-mirror responses, these results support the associative account of mirror neuron origins whereby mirror responses arise as a result of correlated sensorimotor experience during development. More generally, they contribute to theorizing regarding mirror neuron function by providing some constraints on how quickly mirror responses can influence social cognition. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  15. Timecourse of mirror and counter-mirror effects measured with transcranial magnetic stimulation

    Science.gov (United States)

    Cavallo, Andrea; Heyes, Cecilia; Becchio, Cristina; Bird, Geoffrey

    2014-01-01

    The human mirror system has been the subject of much research over the past two decades, but little is known about the timecourse of mirror responses. In addition, it is unclear whether mirror and counter-mirror effects follow the same timecourse. We used single-pulse transcranial magnetic stimulation to investigate the timecourse of mirror and counter-mirror responses in the human brain. Experiment 1 demonstrated that mirror responses can be measured from around 200 ms after observed action onset. Experiment 2 demonstrated significant effects of counter-mirror sensorimotor training at all timepoints at which a mirror response was found in Experiment 1 (i.e. from 200 ms onward), indicating that mirror and counter-mirror responses follow the same timecourse. By suggesting similarly direct routes for mirror and counter-mirror responses, these results support the associative account of mirror neuron origins whereby mirror responses arise as a result of correlated sensorimotor experience during development. More generally, they contribute to theorizing regarding mirror neuron function by providing some constraints on how quickly mirror responses can influence social cognition. PMID:23709352

  16. CubeSat Deformable Mirror Demonstration

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of the CubeSat Deformable Mirror Demonstration is to characterize the performance of a small deformable mirror over a year in low-Earth orbit. Small form...

  17. [The ontogeny of the mirror neuron system].

    Science.gov (United States)

    Myowa-Yamakoshi, Masako

    2014-06-01

    Abstract Humans utilize the mirror neuron system to understand and predict others' actions. However, the ontogeny of the mirror neuron system remains unknown. Whether mirror neuron function is an innate trait or whether mirror neurons acquire their sensorimotor matching properties ontogenetically remains to be clarified. In this paper, I review the ontogenetic theory of the mirror neuron system. I then discuss the functioning of the mirror neuron system in the context of social cognitive abilities, which are unique to humans. Recently, some researchers argue that it is too early to interpret the function of mirror neurons as an understanding of the underlying psychological states of others. They imply that such functioning would require inferential cognitive processes that are known to involve areas outside the mirror neuron system. Filling in this missing link may be the key to elucidating the unique ability of humans to understand others' actions.

  18. Second-quantized mirror symmetry

    CERN Document Server

    Ferrara, Sergio; Strominger, A; Vafa, C

    1995-01-01

    We propose and give strong evidence for a duality relating Type II theories on Calabi-Yau spaces and heterotic strings on K3 \\times T^2, both of which have N=2 spacetime supersymmetry. Entries in the dictionary relating the dual theories are derived from an analysis of the soliton string worldsheet in the context of N=2 orbifolds of dual N=4 compactifications of Type II and heterotic strings. In particular we construct a pairing between Type II string theory on a self-mirror Calabi-Yau space X with h^{11}= h^{21}= 11 and a (4, 0) background of heterotic string theory on K3\\times T^2. Under the duality transformation the usual first-quantized mirror symmetry of X becomes a second-quantized mirror symmetry which determines nonperturbative quantum effects. This enables us to compute the exact quantum moduli space. Mirror symmetry of X implies that the low-energy N=2 gauge theory is finite, even at enhanced symmetry points. This prediction is verified by direct computation on the heterotic side. Other branches of...

  19. On four dimensional mirror symmetry

    International Nuclear Information System (INIS)

    Losev, A.; Nekrasov, N.; Shatashvili, S.

    2000-01-01

    A conjecture relating instanton calculus in four dimensional supersymmetric theories and the deformation theory of Lagrangian submanifolds in C 2r invariant under a (subgroup of) Sp(2r,Z) is formulated. This is a four dimensional counterpart of the mirror symmetry of topological strings (relating Gromov-Witten invariants and generalized variations of Hodge structure). (orig.)

  20. Plasma impact on diagnostic mirrors in JET

    OpenAIRE

    A. Garcia-Carrasco; P. Petersson; M. Rubel; A. Widdowson; E. Fortuna-Zalesna; S. Jachmich; M. Brix; L. Marot

    2017-01-01

    Metallic mirrors will be essential components of all optical systems for plasma diagnosis in ITER. This contribution provides a comprehensive account on plasma impact on diagnostic mirrors in JET with the ITER-Like Wall. Specimens from the First Mirror Test and the lithium-beam diagnostic have been studied by spectrophotometry, ion beam analysis and electron microscopy. Test mirrors made of molybdenum were retrieved from the main chamber and the divertor after exposure to the 2013–2014 experi...

  1. Mirror Advanced Reactor Study (MARS): executive summary and overview

    International Nuclear Information System (INIS)

    Logan, B.G.; Perkins, L.J.; Gordon, J.D.

    1984-07-01

    Two self-consistent MARS configurations are discussed - a 1200-MWe commercial electricity-generating plant and a synguels-generating plant that produces hydrogen with an energy equivalent to 26,000 barrels of oil per day. The MARS machine emphasizes the attractive features of the tandem mirror concept, including steady-state operation, a small-diameter high-beta plasma, a linear central cell with simple low-maintenance blankets, low first-wall heat fluxes ( 2 ), no driven plasma currents or associated disruptions, natural halo impurity diversion, and direct conversion of end-loss charged-particle power. The MARS electric plant produces 2600 MW of fusion power in a 130-m-long central cell. Advanced tandem-mirror plasma-engineering concepts, a high-efficiency liquid lithium-lead (Li 17 Pb 83 ) blanket, and efficient direct electrical conversion of end loss power combine to produce a high net plant efficiency of 36%. With a total capital cost of $2.9 billion (constant 1983 dollars), the MARS electric plant produces busbar electricity at approx. 7 cents/kW-hour. The MARS synfuels plant produces 3500 MW of fusion power in a 150-m-long central cell. A helium-gas-cooled silicon carbide pebble-bed blanket provides high-temperature (1000 0 C) heat to a thermochemical water-splitting cycle and the resulting hydrogen is catalytically converted to methanol for distribution. With a total capital cost of $3.6 billion (constant 1983 dollars), the synfuels plant produces methanol fuel at about $1.7/gal. The major features of the MARS reactor include sloshing-ion thermal barrier plugs for efficient plasma confinement, a high efficiency blanket, high-field (24-T) choke cells, drift pumping for trapped plasma species, quasi-optical electron-cyclotron resonant heating (ECRH) systems, and a component gridless direct converter

  2. Vorticity dynamics of a bileaflet mechanical heart valve in an axisymmetric aorta

    Science.gov (United States)

    Dasi, L. P.; Ge, L.; Simon, H. A.; Sotiropoulos, F.; Yoganathan, A. P.

    2007-06-01

    We present comprehensive particle image velocimetry measurements and direct numerical simulation (DNS) of physiological, pulsatile flow through a clinical quality bileaflet mechanical heart valve mounted in an idealized axisymmetric aorta geometry with a sudden expansion modeling the aortic sinus region. Instantaneous and ensemble-averaged velocity measurements as well as the associated statistics of leaflet kinematics are reported and analyzed in tandem to elucidate the structure of the velocity and vorticity fields of the ensuing flow-structure interaction. The measurements reveal that during the first half of the acceleration phase, the flow is laminar and repeatable from cycle to cycle. The valve housing shear layer rolls up into the sinus and begins to extract vorticity of opposite sign from the sinus wall. A start-up vortical structure is shed from the leaflets and is advected downstream as the leaflet shear layers become wavy and oscillatory. In the second half of flow acceleration the leaflet shear layers become unstable and break down into two von Karman-like vortex streets. The onset of vortex shedding from the valve leaflets is responsible for the growth of significant cycle-to-cycle vorticity oscillations. At peak flow, the housing and leaflet shear layers undergo secondary instabilities and break down rapidly into a chaotic, turbulent-like state with multiple small-scale vortical structures emerging in the flow. During the deceleration and closing phases all large-scale coherent flow features disappear and a chaotic small-scale vorticity field emerges, which persists even after the valve has closed. Probability density functions of the leaflet position during opening and closing phases show that the leaflet position fluctuates from cycle to cycle with larger fluctuations evident during valve closure. The DNS is carried out by prescribing the leaflet kinematics from the experimental data. The computed instantaneous vorticity fields are in very good

  3. JAERI Tandem annual report 1983

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Maruyama, Michio; Okashita, Hiroshi; Ozawa, Kunio; Shikazono, Naomoto; Tanaka, Shigeya

    1984-07-01

    This annual report describes research activities which have been performed with JAERI tandem accelerator from April 1, 1983 to March 31, 1984. Summary reports of 32 papers, publications, personnel and a list of co-operative reserches with universities are contained. (author)

  4. JAERI tandem annual report, 1982

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Maruyama, Michio; Ozawa, Kunio; Shikazono, Naomoto; Tamura, Tsutomu; Tanaka, Shigeya

    1983-06-01

    This annual report describes research activities which have been performed with JAERI tandem accelerator from September 1, 1981 to March 31, 1983. Summary reports of 38 papers, publications, personnel and a list of co-operative researches with universities are contained. (author)

  5. Acoustic Scattering by Axisymmetric Finite-Length Bodies with Application to Fish: Measurement and Modeling

    National Research Council Canada - National Science Library

    Reeder, D

    2002-01-01

    ... laboratory acoustic measurements. A general acoustic scattering model is developed that is accurate and numerically efficient for a wide range of frequencies, angles of orientation, irregular axisymmetric shapes and boundary...

  6. Computation of steady and unsteady compressible quasi-axisymmetric vortex flow and breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1991-01-01

    The unsteady, compressible Navier-Stokes equations are used to compute and analyze compressible quasi-axisymmetric isolated vortices. The Navier-Stokes equations are solved using an implicit, upwind, flux-difference splitting finite-volume scheme. The developed three-dimensional solver has been verified by comparing its solution profiles with those of a slender, quasi-axisymmetric vortex solver for a subsonic, isolated quasi-axisymmetric vortex in an unbounded domain. The Navier-Stokes solver is then used to solve for a supersonic quasi-axisymmetric vortex flow in a configured circular duct. Steady and unsteady vortex-shock interactions and breakdown have been captured. The problem has also been calculated using the Euler solver of the same code and the results are compared with those of the Navier-Stokes solver. The effect of the initial swirl has been tentatively studied.

  7. Computation of compressible quasi-axisymmetric slender vortex flow and breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.

    1991-01-01

    The unsteady, compressible Navier-Stokes equations are used to compute and analyze compressible quasi-axisymmetric isolated vortices. The Navier-Stokes equations are solved using an implicit, upwind, flux difference splitting finite volume scheme. The developed three dimensional solver was verified by comparing its solution profiles with those of a slender, quasi-axisymmetric vortex solver for a subsonic, quasi-axisymmetric vortex in an unbounded domain. The Navier-Stokes solver is then used to solve for a supersonic, quasi-axisymmetric vortex flow in a configured circular duct. Steady and unsteady vortex-shock interactions and breakdown were captured. The problem was also calculated using the Euler solver of the same code; the results were compared with those of the Navier-Stokes solver. The effect of the initial swirl was investigated.

  8. Experiences with the use of axisymmetric elements in cosmic NASTRAN for static analysis

    Science.gov (United States)

    Cooper, Michael J.; Walton, William C.

    1991-01-01

    Discussed here are some recent finite element modeling experiences using the axisymmetric elements CONEAX, TRAPAX, and TRIAAX, from the COSMIC NASTRAN element library. These experiences were gained in the practical application of these elements to the static analysis of helicopter rotor force measuring systems for two design projects for the NASA Ames Research Center. These design projects were the Rotor Test Apparatus and the Large Rotor Test Apparatus, which are dedicated to basic helicopter research. Here, a genetic axisymmetric model is generated for illustrative purposes. Modeling considerations are discussed, and the advantages and disadvantages of using axisymmetric elements are presented. Asymmetric mechanical and thermal loads are applied to the structure, and single and multi-point constraints are addressed. An example that couples the axisymmetric model to a non-axisymmtric model is demonstrated, complete with DMAP alters. Recommendations for improving the elements and making them easier to use are offered.

  9. Reflection of OH molecules from magnetic mirrors

    NARCIS (Netherlands)

    Metsaelae, Markus; Gilijamse, Joop J.; Hoekstra, Steven; van de Meerakker, Sebastiaan Y. T.; Meijer, Gerard

    2008-01-01

    We have reflected a Stark-decelerated beam of OH molecules under normal incidence from mirrors consisting of permanent magnets. Two different types of magnetic mirrors have been demonstrated. A long-range flat mirror made from a large disc magnet has been used to spatially focus the reflected beam

  10. The mirror neuron system : New frontiers

    NARCIS (Netherlands)

    Keysers, Christian; Fadiga, Luciano

    2008-01-01

    Since the discovery of mirror neurons, much effort has been invested into Studying their location and properties in the human brain. Here we review these original findings and introduce the Main topics of this special issue of Social Neuroscience. What does the mirror system code? How is the mirror

  11. 21 CFR 886.1500 - Headband mirror.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Headband mirror. 886.1500 Section 886.1500 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1500 Headband mirror. (a) Identification. A headband mirror is a device intended to be strapped to the head of the user to reflect light for use in...

  12. A generalized construction of mirror manifolds

    International Nuclear Information System (INIS)

    Berglund, P.; Huebsch, T.

    1993-01-01

    We generalize the known method for explicit construction of mirror pairs of (2,2)-superconformal field theories, using the formalism of Landau-Ginzburg orbifolds. Geometrically, these theories are realized as Calabi-Yau hypersurfaces in weighted projective spaces. This generalization makes it possible to construct the mirror partners of many manifolds for which the mirror was not previously known. (orig.)

  13. Prediction of mirror performance from laboratory measurements

    International Nuclear Information System (INIS)

    Church, E.L.; Takacs, P.Z.

    1989-01-01

    This paper describes and illustrates a simple method of predicting the imaging performance of synchrotron mirrors from laboratory measurements of their profiles. It discusses the important role of the transverse coherence length of the incident radiation, the fractal-like form of the mirror roughness, mirror characterization, and the use of closed-form expressions for the predicted image intensities

  14. EFFECTS OF LARGE-SCALE NON-AXISYMMETRIC PERTURBATIONS IN THE MEAN-FIELD SOLAR DYNAMO

    Energy Technology Data Exchange (ETDEWEB)

    Pipin, V. V. [Institute of Solar-Terrestrial Physics, Russian Academy of Sciences (Russian Federation); Kosovichev, A. G. [W.W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2015-11-10

    We explore the response of a nonlinear non-axisymmetric mean-field solar dynamo model to shallow non-axisymmetric perturbations. After a relaxation period, the amplitude of the non-axisymmetric field depends on the initial condition, helicity conservation, and the depth of perturbation. It is found that a perturbation that is anchored at 0.9 R{sub ⊙} has a profound effect on the dynamo process, producing a transient magnetic cycle of the axisymmetric magnetic field, if it is initiated at the growing phase of the cycle. The non-symmetric, with respect to the equator, perturbation results in a hemispheric asymmetry of the magnetic activity. The evolution of the axisymmetric and non-axisymmetric fields depends on the turbulent magnetic Reynolds number R{sub m}. In the range of R{sub m} = 10{sup 4}–10{sup 6} the evolution returns to the normal course in the next cycle, in which the non-axisymmetric field is generated due to a nonlinear α-effect and magnetic buoyancy. In the stationary state, the large-scale magnetic field demonstrates a phenomenon of “active longitudes” with cyclic 180° “flip-flop” changes of the large-scale magnetic field orientation. The flip-flop effect is known from observations of solar and stellar magnetic cycles. However, this effect disappears in the model, which includes the meridional circulation pattern determined by helioseismology. The rotation rate of the non-axisymmetric field components varies during the relaxation period and carries important information about the dynamo process.

  15. EUV multilayer mirror, optical system including a multilayer mirror and method of manufacturing a multilayer mirror

    NARCIS (Netherlands)

    Huang, Qiushi; Louis, Eric; Bijkerk, Frederik; de Boer, Meint J.; von Blanckenhagen, G.

    2016-01-01

    A multilayer mirror (M) reflecting extreme ultraviolet (EUV) radiation from a first wave-length range in a EUV spectral region comprises a substrate (SUB) and a stack of layers (SL) on the substrate, the stack of layers comprising layers comprising a low index material and a high index material, the

  16. User's manual for the FLORA equilibrium and stability code

    International Nuclear Information System (INIS)

    Freis, R.P.; Cohen, B.I.

    1985-01-01

    This document provides a user's guide to the content and use of the two-dimensional axisymmetric equilibrium and stability code FLORA. FLORA addresses the low-frequency MHD stability of long-thin axisymmetric tandem mirror systems with finite pressure and finite-larmor-radius effects. FLORA solves an initial-value problem for interchange, rotational, and ballooning stability

  17. Dielectric tensor operator of hot plasmas in toroidal axisymmetric systems

    International Nuclear Information System (INIS)

    Brunner, S.; Vaclavik, J.

    1992-08-01

    Kinetic theory is used to develop equations describing dynamics of small-amplitude electromagnetic perturbations in toroidal axisymmetric plasmas. The closed Vlasov-Maxwell equations are first solved for a hot stationary plasma using the expansion in the small parameter ε e =ρ/L, where ρ is the Larmor radius and L a characteristic length scale of the stationary state. The ordering and additional assumptions are specified so as to obtain the well-known Grad-Shafranov equation. The dielectric tensor of such a plasma is then derived. The Vlasov equation for the perturbed distribution function is solved by the expansion in the small parameters ε e and ε p =ρ/λ, where λ is a characteristic wavelength of the perturbing electromagnetic field. The solution is obtained up to the first order in ε e and the second order in ε p . By integrating the resulting distribution function over velocity space, an explicit expression for the tensor is derived in the form of a two-dimensional partial differential operator. The operator is shown to possess the proper symmetry corresponding to the energy conservation law. (author) 6 refs

  18. Axisymmetric core collapse simulations using characteristic numerical relativity

    International Nuclear Information System (INIS)

    Siebel, Florian; Mueller, Ewald; Font, Jose A.; Papadopoulos, Philippos

    2003-01-01

    We present results from nonrotating axisymmetric stellar core collapse simulations in general relativity. Our hydrodynamics code has proved robust and accurate enough to allow for a detailed analysis of the global dynamics of the collapse. Contrary to traditional approaches based on the 3+1 formulation of the gravitational field equations, our framework uses a foliation based on a family of outgoing light cones, emanating from a regular center, and terminating at future null infinity. Such a coordinate system is well adapted to the study of interesting dynamical spacetimes in relativistic astrophysics such as stellar core collapse and neutron star formation. Perhaps most importantly this procedure allows for the extraction of gravitational waves at future null infinity, along with the commonly used quadrupole formalism for the gravitational wave extraction. Our results concerning the gravitational wave signals show noticeable disagreement when those are extracted by computing the Bondi news at future null infinity on the one hand and by using the quadrupole formula on the other hand. We have a strong indication that for our setup the quadrupole formula on the null cone does not lead to physical gravitational wave signals. The Bondi gravitational wave signals extracted at infinity show typical oscillation frequencies of about 0.5 kHz

  19. Linear theory of the tearing instability in axisymmetric toroidal devices

    International Nuclear Information System (INIS)

    Rogister, A.; Singh, R.

    1988-08-01

    We derive a very general kinetic equation describing the linear evolution of low m/l modes in axisymmetric toroidal plasmas with arbitrary cross sections. Included are: Ion sound, inertia, diamagnetic drifts, finite poloidal beta, and finite ion Larmor radius effects. Assuming the magnetic surfaces to form a set of nested tori with circular cross sections of shifted centers, and introducing adequate simplifications justified by our knowledge of experimental tokamak plasmas, we then obtain explicitely the sets of equations describing the coupling of the quasimodes 0/1, 1/1, 2/1, and, for m≥2, m/1, (m+1)/1. By keeping finite aspect ratio effects into account when calculating the jump of the derivative of the eigenfunction, it is shown that the theory can explain the rapid evolution, within one sawtooth period, of the growth rate of the sawteeth precursors from resistive values to magnetohydrodynamic ones. The characteristics thus theoretically required from current profiles in sawtoothing discharges have clearly been observed. Other aspects of the full theory could be relevant to the phenomenon of major disruptions. (orig.)

  20. Direct numerical simulation of axisymmetric laminar low-density jets

    Science.gov (United States)

    Gomez Lendinez, Daniel; Coenen, Wilfried; Sevilla, Alejandro

    2017-11-01

    The stability of submerged laminar axisymmetric low-density jets has been investigated experimentally (Kyle & Sreenivasan 1993, Hallberg & Strykowski 2006) and with linear analysis (Jendoubi & Strykowski 1994, Coenen & Sevilla 2012, Coenen et al. 2017). These jets become globally unstable when the Reynolds number is larger than a certain critical value which depends on the density ratio and on the velocity profile at the injector outlet. In this work, Direct Numerical Simulations using FreeFEM + + (Hecht 2012) with P1 elements for pressure and P2 for velocity and density are performed to complement the above mentioned studies. Density and velocity fields are analyzed at long time showing the unforced space-time evolution of nonlinear disturbances propagating along the jet. Using the Stuart-Landau model to fit the numerical results for the self-excited oscillations we have computed a neutral stability curve that shows good agreement with experiments and stability theory. Thanks to Spanish MINECO under projects DPI2014-59292-C3-1-P and DPI2015-71901-REDT for financial support.

  1. Adhesion and detachment of a capsule in axisymmetric flow

    Science.gov (United States)

    Keh, M. P.; Leal, L. G.

    2016-05-01

    The adhesion and detachment of a capsule on a solid boundary surface is studied via a combination of scaling theory and numerical simulation and the behavior is compared and contrasted with a vesicle. It is shown that the dominant physical property for both capsules and vesicles is the area dilation modulus Ks of the membrane. The nonzero shear modulus Gs for capsules increases the resistance to deformation and thus decreases slightly the equilibrium contact radius for an adhered capsule compared to an adhered vesicle. The detachment process in this study is due to an external axisymmetric flow. Unlike a rigid body that must be pulled away without change of shape, capsules (and vesicles) almost always detach dominantly by peeling in which the contact radius decreases but the minimum separation distance does not change until the final moments of detachment. Compared to a vesicle with the same Ks, a capsule maintains a more compact shape and is harder to elongate under a given external flow. Hence, the detachment process is slower for capsules compared to vesicles with the same Ks.

  2. Plasma equilibria and stationary flows in axisymmetric systems. Pt. 3

    International Nuclear Information System (INIS)

    Zelazny, R.; Stankiewicz, R.; Galkowski, A.; Potempski, S.; Pietak, R.

    1990-08-01

    The problem of the importance of poloidal flows for the behaviour of plasmas in axisymmetric systems has caused a lot of discussion and controversy during the last 15 years. There is no doubt that the mere existence of poloidal flow transforms the elliptic Grad-Shafranov-Schlueter equation into a system of mixed type partial differential equation and an algebraic multivalued Bernoulli equation. This fact leads to the appearance of Bernoulli branches in the solutions. Then, one can come across three branches of elliptic solutions as well as two branches of hyperbolic solutions with the possible appearance of phenomena connected with ''transsonic'' effects. Problems connected with such a mathematical situation have been extensively discussed in the report with the same title, dated May 1988, which we shall call later Part I of our studies on this subject. The present report, considered as Part III, is devoted to the presentation of results of efforts aimed at constructing programmes which allow us to solve the extended Grad-Shafranov-Schlueter equation (EGSS) (with stationary flows) in a more realistic situation relevant to the JET operating conditions. The main problem is to specify for a wider class of profiles the boundary conditions at the magnetic axis for a system of nonlinear ordinary differential equations ODE, resulting from EGSS equation after application of Fourier transformation techniques and of inverse method approach. The present report elaborates a much more general case and describes the computational framework enabling us to derive those boundary conditions. (author)

  3. Uniformly rotating, axisymmetric, and triaxial quark stars in general relativity

    Science.gov (United States)

    Zhou, Enping; Tsokaros, Antonios; Rezzolla, Luciano; Xu, Renxin; Uryū, Kōji

    2018-01-01

    Quasiequilibrium models of uniformly rotating axisymmetric and triaxial quark stars are computed in a general-relativistic gravity scenario. The Isenberg-Wilson-Mathews (IWM) formulation is employed and the Compact Object Calculator (cocal) code is extended to treat rotating stars with finite surface density and new equations of state (EOSs). Besides the MIT bag model for quark matter which is composed of deconfined quarks, we examine a new EOS proposed by Lai and Xu that is based on quark clustering and results in a stiff EOS that can support masses up to 3.3 M⊙ in the case we considered. We perform convergence tests for our new code to evaluate the effect of finite surface density in the accuracy of our solutions and construct sequences of solutions for both small and high compactness. The onset of secular instability due to viscous dissipation is identified and possible implications are discussed. An estimate of the gravitational wave amplitude and luminosity based on quadrupole formulas is presented and comparison with neutron stars is discussed.

  4. Turbulent contributions to Ohm's law in axisymmetric magnetized plasmas

    Science.gov (United States)

    Chavdarovski, I.; Gatto, R.

    2017-07-01

    The effect of magnetic turbulence in shaping the current density in axisymmetric magnetized plasmas is analyzed using a turbulent extension of Ohm's law derived from the self-consistent action-angle transport theory. Besides the well-known hyper-resistive (helicity-conserving) contribution, the generalized Ohm's law contains an anomalous resistivity term and a turbulent bootstrap-like term proportional to the current density derivative. The numerical solution of the equation for equilibrium and turbulence profiles characteristic of conventional and advanced scenarios shows that, through the "turbulent bootstrap" effect and anomalous resistivity, power and parallel current can be generated which are a sizable portion (about 20%-25%) of the corresponding effects associated with the neoclassical bootstrap effect. The degree of alignment of the turbulence peak and the pressure gradient plays an important role in defining the steady-state regime. In a fully bootstrapped tokamak, the hyper-resistivity is essential in overcoming the intrinsic limitation of the hollow current profile.

  5. Transverse linear dynamics in an axisymmetric ionization cooling channel

    Directory of Open Access Journals (Sweden)

    G. Dugan

    2001-10-01

    Full Text Available This paper outlines a formalism for the description of the linear transverse dynamics of charged particles in an axisymmetric ionization cooling channel. The particle trajectories in the absence of Coulomb scattering are described in terms of lattice functions à la Courant and Snyder, which depend only on the electric and magnetic fields in the channel. The process of multiple Coulomb scattering, which introduces stochastic terms into the particle equations of motion, is treated (in Gaussian approximation by obtaining the distribution function in phase space as a solution of a Fokker-Planck equation. The distribution function is then used to obtain moment equations for the transverse variables and for combinations of variables such as the emittance and angular momentum. The distribution function is also used to obtain an expression for the peak four-dimensional phase space density and for the fraction of the beam that is within a certain area in phase space. The special case of a periodic channel is then considered and expressions for the asymptotic rms emittance and peak phase space density are obtained. Finally, the application of the general formalism to a numerical example, based on the reported design of a cooling channel for a neutrino source, is considered, and comparisons are made with numerical simulations of that channel.

  6. First integrals of the axisymmetric shape equation of lipid membranes

    Science.gov (United States)

    Zhang, Yi-Heng; McDargh, Zachary; Tu, Zhan-Chun

    2018-03-01

    The shape equation of lipid membranes is a fourth-order partial differential equation. Under the axisymmetric condition, this equation was transformed into a second-order ordinary differential equation (ODE) by Zheng and Liu (Phys. Rev. E 48 2856 (1993)). Here we try to further reduce this second-order ODE to a first-order ODE. First, we invert the usual process of variational calculus, that is, we construct a Lagrangian for which the ODE is the corresponding Euler–Lagrange equation. Then, we seek symmetries of this Lagrangian according to the Noether theorem. Under a certain restriction on Lie groups of the shape equation, we find that the first integral only exists when the shape equation is identical to the Willmore equation, in which case the symmetry leading to the first integral is scale invariance. We also obtain the mechanical interpretation of the first integral by using the membrane stress tensor. Project supported by the National Natural Science Foundation of China (Grant No. 11274046) and the National Science Foundation of the United States (Grant No. 1515007).

  7. Axisymmetric bifurcations of thick spherical shells under inflation and compression

    KAUST Repository

    deBotton, G.

    2013-01-01

    Incremental equilibrium equations and corresponding boundary conditions for an isotropic, hyperelastic and incompressible material are summarized and then specialized to a form suitable for the analysis of a spherical shell subject to an internal or an external pressure. A thick-walled spherical shell during inflation is analyzed using four different material models. Specifically, one and two terms in the Ogden energy formulation, the Gent model and an I1 formulation recently proposed by Lopez-Pamies. We investigate the existence of local pressure maxima and minima and the dependence of the corresponding stretches on the material model and on shell thickness. These results are then used to investigate axisymmetric bifurcations of the inflated shell. The analysis is extended to determine the behavior of a thick-walled spherical shell subject to an external pressure. We find that the results of the two terms Ogden formulation, the Gent and the Lopez-Pamies models are very similar, for the one term Ogden material we identify additional critical stretches, which have not been reported in the literature before.© 2012 Published by Elsevier Ltd.

  8. Equilibrium and Stability Properties of Low Aspect Ratio Mirror Systems: from Neutron Source Design to the Parker Spiral

    Science.gov (United States)

    Peterson, Ethan; Anderson, Jay; Clark, Mike; Egedal, Jan; Endrizzi, Douglass; Flanagan, Ken; Harvey, Robert; Lynn, Jacob; Milhone, Jason; Wallace, John; Waleffe, Roger; Mirnov, Vladimir; Forest, Cary

    2017-10-01

    Equilibrium reconstructions of rotating magnetospheres in the lab are computed using a user-friendly extended Grad-Shafranov solver written in Python and various magnetic and kinetic measurements. The stability of these equilibria are investigated using the NIMROD code with two goals: understand the onset of the classic ``wobble'' in the heliospheric current sheet and demonstrating proof-of-principle for a laboratory source of high- β turbulence. Using the same extended Grad-Shafranov solver, equilibria for an axisymmetric, non-paraxial magnetic mirror are used as a design foundation for a high-field magnetic mirror neutron source. These equilibria are numerically shown to be stable to the m=1 flute instability, with higher modes likely stabilized by FLR effects; this provides stability to gross MHD modes in an axisymmetric configuration. Numerical results of RF heating and neutral beam injection (NBI) from the GENRAY/CQL3D code suite show neutron fluxes promising for medical radioisotope production as well as materials testing. Synergistic effects between NBI and high-harmonic fast wave heating show large increases in neutron yield for a modest increase in RF power. work funded by DOE, NSF, NASA.

  9. [What mirror neurons have revealed: revisited].

    Science.gov (United States)

    Murata, Akira; Maeda, Kazutaka

    2014-06-01

    The first paper on mirror neurons was published in 1992. In the span of over two decades since then, much knowledge about the relationship between social cognitive function and the motor control system has been accumulated. Direct matching of visual actions and their corresponding motor representations is the most important functional property of mirror neuron. Many studies have emphasized intrinsic simulation as a core concept for mirror neurons. Mirror neurons are thought to play a role in social cognitive function. However, the function of mirror neurons in the macaque remains unclear, because such cognitive functions are limited or lacking in macaque monkeys. It is therefore important to discuss these neurons in the context of motor function. Rizzolatti and colleagues have stressed that the most important function of mirror neurons in macaques is recognition of actions performed by other individuals. I suggest that mirror neurons in the Macaque inferior pariental lobule might be correlated with body schema. In the parieto-premotor network, matching of corollary discharge and actual sensory feedback is an essential neuronal operation. Recently, neurons showing mirror properties were found in some cortical areas outside the mirror neuron system. The current work would revisit the outcomes of mirror neuron studies to discuss the function of mirror neurons in the monkey.

  10. Mirror neurons: their implications for group psychotherapy.

    Science.gov (United States)

    Schermer, Victor L

    2010-10-01

    Recently discovered mirror neurons in the motor cortex of the brain register the actions and intentions of both the organism and others in the environment. As such, they may play a significant role in social behavior and groups. This paper considers the potential implications of mirror neurons and related neural networks for group therapists, proposing that mirror neurons and mirror systems provide "hard-wired" support for the group therapist's belief in the centrality of relationships in the treatment process and exploring their value in accounting for group-as-a-whole phenomena. Mirror neurons further confirm the holistic, social nature of perception, action, and intention as distinct from a stimulus-response behaviorism. The implications of mirror neurons and mirroring processes for the group therapist role, interventions, and training are also discussed.

  11. Mirror fusion vacuum technology developments

    International Nuclear Information System (INIS)

    Batzer, T.H.; Call, W.R.

    1983-01-01

    Magnetic Mirror Fusion experiments, such as MFTF-B+T (Mirror Fusion Test Facility-B, Tritium Upgrade) and foreseeable follow-on devices, have operational and maintenance requirements that have not yet been fully demonstrated. Among those associated with vacuum technology are the very-high continuous-pumping speeds, 10 7 to 10 8 l/s for D 2 , T 2 and, to a lesser extent, He; the early detection of water leaks from the very-high heat-flux neutral-beam dumps and the detection and location of leaks in the superconducting magnets not protected by guard vacuums. Possible solutions to these problems have been identified and considerable progress has been made toward successfully demonstrating their feasibility

  12. Mirror hybrid reactor optimization studies

    International Nuclear Information System (INIS)

    Bender, D.J.

    1976-01-01

    A system model of the mirror hybrid reactor has been developed. The major components of the model include (1) the reactor description, (2) a capital cost analysis, (3) various fuel management schemes, and (4) an economic analysis that includes the hybrid plus its associated fission burner reactors. The results presented describe the optimization of the mirror hybrid reactor, the objective being to minimize the cost of electricity from the hybrid fission-burner reactor complex. We have examined hybrid reactors with two types of blankets, one containing natural uranium, the other thorium. The major difference between the two optimized reactors is that the uranium hybrid is a significant net electrical power producer, whereas the thorium hybrid just about breaks even on electrical power. Our projected costs for fissile fuel production are approximately 50 $/g for 239 Pu and approximately 125 $/g for 233 U

  13. Imitation, mirror neurons and autism

    OpenAIRE

    Williams, Justin H.G.; Whiten, Andrew; Suddendorf, Thomas; Perrett, David I.

    2001-01-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show ac...

  14. Nanocrystal assembly for tandem catalysis

    Science.gov (United States)

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

    2014-10-14

    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  15. Tandem electrostatic accelerators for BNCT

    International Nuclear Information System (INIS)

    Ma, J.C.

    1994-01-01

    The development of boron neutron capture therapy (BNCT) into a viable therapeutic modality will depend, in part, on the availability of suitable neutron sources compatible with installation in a hospital environment. Low-energy accelerator-based intense neutron sources, using electrostatic or radio frequency quadrupole proton accelerators have been suggested for this purpose and are underdevelopment at several laboratories. New advances in tandem electrostatic accelerator technology now allow acceleration of the multi-milliampere proton beams required to produce therapeutic neutron fluxes for BNCT. The relatively compact size, low weight and high power efficiency of these machines make them particularly attractive for installation in a clinical or research facility. The authors will describe the limitations on ion beam current and available neutron flux from tandem accelerators relative to the requirements for BNCT research and therapy. Preliminary designs and shielding requirements for a tandern accelerator-based BNCT research facility will also be presented

  16. MR-Tandem: parallel X!Tandem using Hadoop MapReduce on Amazon Web Services.

    Science.gov (United States)

    Pratt, Brian; Howbert, J Jeffry; Tasman, Natalie I; Nilsson, Erik J

    2012-01-01

    MR-Tandem adapts the popular X!Tandem peptide search engine to work with Hadoop MapReduce for reliable parallel execution of large searches. MR-Tandem runs on any Hadoop cluster but offers special support for Amazon Web Services for creating inexpensive on-demand Hadoop clusters, enabling search volumes that might not otherwise be feasible with the compute resources a researcher has at hand. MR-Tandem is designed to drop in wherever X!Tandem is already in use and requires no modification to existing X!Tandem parameter files, and only minimal modification to X!Tandem-based workflows. MR-Tandem is implemented as a lightly modified X!Tandem C++ executable and a Python script that drives Hadoop clusters including Amazon Web Services (AWS) Elastic Map Reduce (EMR), using the modified X!Tandem program as a Hadoop Streaming mapper and reducer. The modified X!Tandem C++ source code is Artistic licensed, supports pluggable scoring, and is available as part of the Sashimi project at http://sashimi.svn.sourceforge.net/viewvc/sashimi/trunk/trans_proteomic_pipeline/extern/xtandem/. The MR-Tandem Python script is Apache licensed and available as part of the Insilicos Cloud Army project at http://ica.svn.sourceforge.net/viewvc/ica/trunk/mr-tandem/. Full documentation and a windows installer that configures MR-Tandem, Python and all necessary packages are available at this same URL. brian.pratt@insilicos.com

  17. "Nanocrystal bilayer for tandem catalysis"

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  18. Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows

    KAUST Repository

    Scribano, Gianfranco

    2016-12-29

    The counterflow configuration is a canonical stagnation flow, featuring two opposed impinging round jets and a mixing layer across the stagnation plane. Although counterflows are used extensively in the study of reactive mixtures and other applications where mixing of two streams is required, quantitative data on the scaling properties of the flow field are lacking. The aim of this work is to characterize the velocity and mixing fields in isothermal counterflows over a wide range of conditions. The study features both experimental data from particle image velocimetry and results from detailed axisymmetric simulations. The scaling laws for the nondimensional velocity and mixture fraction are obtained as a function of an appropriate Reynolds number and the ratio of the separation distance of the nozzles to their diameter. In the range of flow configurations investigated, the nondimensional fields are found to depend primarily on the separation ratio and, to a lesser extent, the Reynolds number. The marked dependence of the velocity field with respect to the separation ratio is linked to a high pressure region at the stagnation point. On the other hand, Reynolds number effects highlight the role played by the wall boundary layer on the interior of the nozzles, which becomes less important as the separation ratio decreases. The normalized strain rate and scalar dissipation rate at the stagnation plane are found to attain limiting values only for high values of the Reynolds number. These asymptotic values depend markedly on the separation ratio and differ significantly from the values produced by analytical models. The scaling of the mixing field does not show a limiting behavior as the separation ratio decreases to the smallest practical value considered.

  19. Computer Aided Process Planning for Non-Axisymmetric Deep Drawing Products

    Science.gov (United States)

    Park, Dong Hwan; Yarlagadda, Prasad K. D. V.

    2004-06-01

    In general, deep drawing products have various cross-section shapes such as cylindrical, rectangular and non-axisymmetric shapes. The application of the surface area calculation to non-axisymmetric deep drawing process has not been published yet. In this research, a surface area calculation for non-axisymmetric deep drawing products with elliptical shape was constructed for a design of blank shape of deep drawing products by using an AutoLISP function of AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. However, the application of the system to non-axisymmetric components has not been reported yet. Thus, the CAPP system for non-axisymmetric deep drawing products with elliptical shape was constructed by using process sequence design. The system developed in this work consists of four modules. The first is recognition of shape module to recognize non-axisymmetric products. The second is a three-dimensional (3-D) modeling module to calculate the surface area for non-axisymmetric products. The third is a blank design module to create an oval-shaped blank with the identical surface area. The forth is a process planning module based on the production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. Especially, the drawing coefficient, the punch and die radii for elliptical shape products are considered as main design parameters. The suitability of this system was verified by applying to a real deep drawing product. This CAPP system constructed would be very useful to reduce lead-time for manufacturing and improve an accuracy of products.

  20. Mirrors, mirrors on the wall…the ubiquitous multiple reflection error.

    Science.gov (United States)

    Lawson, Rebecca

    2012-01-01

    Participants decided when somebody, Janine, could see their face in a horizontal row of adjacent mirrors mounted flat on the same wall. They saw real mirrors and a shop-dummy representing Janine. Such coplanar mirrors reflect different, non-overlapping areas of a scene. However, almost everybody made an unexpected error: they claimed that Janine would see her face reflected in multiple mirrors simultaneously. They therefore responded as if each mirror showed similar information and thus grossly overestimated how much each mirror revealed. Further studies established that this multiple reflection error also occurred for vertical rows of mirrors and for different areas of a single, large mirror. The error was even common if the participant themselves sat in front of a set of covered-up mirrors and indicated where they would be able to see their own reflection. In the latter case, people often made multiple reflection errors despite having seen all the mirrors uncovered immediately before they responded. People's gross overestimation of how much of a scene a mirror reflects and their inability to learn to correct this false belief explains why, despite a lifetime's experience of mirrors, they incorrectly think they will see themselves in all nearby mirrors. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. SICOS, 2-D Time-Dependent Creep Calculation of Plane or Axisymmetric Concrete Structure

    International Nuclear Information System (INIS)

    Plettenberg, W.; Schmidt, A.

    1984-01-01

    1 - Description of problem or function: Two-dimensional program for time-dependent calculation of plane and axisymmetric composite con- crete structures. Assumed material behaviour: - linear viscoelasticity (creep) for the concrete - Hooke's Law for liner and reinforcement The given structure may be represented by: - triangular constant strain concrete elements, plane or axisymmetric - plane or axisymmetric membrane steel elements (liner) - one-dimensional steel elements, in plane or axisymmetric geometry (prestress cables). Transient pressure loads and temperature distributions may be taken into account. Options for mesh generation, calculation of temperature distributions, restart and the representation of results are included. 2 - Method of solution: The program uses the finite-element method. The solution of the linear equation systems is performed either by utilization of the Gauss-Seidel iteration or by direct Gauss elimination possibly with reiteration. The calculation can also be per- formed with double-precision. 3 - Restrictions on the complexity of the problem: Restriction to axisymmetric and plane problems. Only linear-viscoelastic creep behaviour. No possibility of taking into account aging and shrinkage

  2. Standard specification for silvered flat glass mirror

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done. 1.2 This specification covers the quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to 6 mm (¼ in.) thick. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses. 1.3 This specification does not address safety glazing materials nor requirements for mirror applications. Consult model building codes and other applicable standards for safety glazing applications. 1.4 Mirrors covered in this specification are not intended for use in environments where high humidity or airborne corrosion promoters, or both, are consistently present (such as swimming pool areas, ocean-going vessels, chemical laboratories and other corrosive environments). 1.5 The dimensional val...

  3. Deformable mirrors development program at ESO

    Science.gov (United States)

    Stroebele, Stefan; Vernet, Elise; Brinkmann, Martin; Jakob, Gerd; Lilley, Paul; Casali, Mark; Madec, Pierre-Yves; Kasper, Markus

    2016-07-01

    Over the last decade, adaptive optics has become essential in different fields of research including medicine and industrial applications. With this new need, the market of deformable mirrors has expanded a lot allowing new technologies and actuation principles to be developed. Several E-ELT instruments have identified the need for post focal deformable mirrors but with the increasing size of the telescopes the requirements on the deformable mirrors become more demanding. A simple scaling up of existing technologies from few hundred actuators to thousands of actuators will not be sufficient to satisfy the future needs of ESO. To bridge the gap between available deformable mirrors and the future needs for the E-ELT, ESO started a development program for deformable mirror technologies. The requirements and the path to get the deformable mirrors for post focal adaptive optics systems for the E-ELT is presented.

  4. Ring mirror fiber laser gyroscope

    Science.gov (United States)

    Shalaby, Mohamed Y.; Khalil, Kamal; Afifi, Abdelrahman E.; Khalil, Diaa

    2017-02-01

    In this work we present a new architecture for a laser gyroscope based on the use of a Sagnac fiber loop mirror. The proposed system has the unique property that its scale factor can be increased by increasing the gain of the optical amplifier used in the system as demonstrated experimentally using standard single mode fiber and explained physically by the system operation. The proposed gyroscope system is also capable of identifying the direction of rotation. This new structure opens the door for a new category of low cost optical gyroscopes.

  5. Deformable Mirrors Correct Optical Distortions

    Science.gov (United States)

    2010-01-01

    By combining the high sensitivity of space telescopes with revolutionary imaging technologies consisting primarily of adaptive optics, the Terrestrial Planet Finder is slated to have imaging power 100 times greater than the Hubble Space Telescope. To this end, Boston Micromachines Corporation, of Cambridge, Massachusetts, received Small Business Innovation Research (SBIR) contracts from the Jet Propulsion Laboratory for space-based adaptive optical technology. The work resulted in a microelectromechanical systems (MEMS) deformable mirror (DM) called the Kilo-DM. The company now offers a full line of MEMS DMs, which are being used in observatories across the world, in laser communication, and microscopy.

  6. Charged particle confinement in magnetic mirror

    International Nuclear Information System (INIS)

    Bora, D.; John, P.I.; Saxena, Y.C.; Varma, R.K.

    1982-01-01

    The behaviour of single charged particle trapped in a magnetic mirror has been investigated experimentally. The particle injected off axis and trapped in a magnetic mirror, leak out of the mirror with the leakage characterized by multiple decay times. The observed decay times are in good agreement with predictions of a ''wave mechanical like'' model by Varma, over a large range of relevant parameters. (author)

  7. MIRROR THERAPY: A REVIEW OF EVIDENCES

    OpenAIRE

    Aishath Najiha; Jagatheesan Alagesan; Vandana J. Rathod; Poongundran Paranthaman

    2015-01-01

    The aim of this review was to identify and summarize the existing evidences on mirror box therapy for the management of various musculoskeletal conditions. A systemic literature search was performed to identify studies concerning mirror therapy. The included journal articles were reviewed and assessed for its significance. Fifty one studies were identified and reviewed. Five different patient categories were studied: 24 studies focussed on mirror therapy after stroke, thirteen studies focusse...

  8. Mirror neurons: From origin to function

    OpenAIRE

    Cook, R; Bird, G; Catmur, C; Press, C; Heyes, C

    2014-01-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively...

  9. Mounting with compliant cylinders for deformable mirrors.

    Science.gov (United States)

    Reinlein, Claudia; Goy, Matthias; Lange, Nicolas; Appelfelder, Michael

    2015-04-01

    A method is presented to mount large aperture unimorph deformable mirrors by compliant cylinders (CC). The CCs are manufactured from a soft silicone, and shear testing is performed in order to evaluate the Young's modulus. A scale mirror model is assembled to evaluate mount-induced change of piezoelectric deformation, and its applicability for tightly focusing mirrors. Experiments do not show any decrease of piezoelectric stroke. Further it is shown that the changes of surface fidelity by the attachment of the deformable mirror to its mount are neglectable.

  10. Testing the egocentric mirror-rotation hypothesis.

    Science.gov (United States)

    Muelenz, Cornelius; Hecht, Heiko; Gamer, Matthias

    2010-01-01

    Although observers know about the law of reflection, their intuitive understanding of spatial locations in mirrors is often erroneous. Hecht et al. (2005) proposed a two-stage mirror-rotation hypothesis to explain these misconceptions. The hypothesis involves an egocentric bias to the effect that observers behave as if the mirror surface were rotated by about 2 degrees to be more orthogonal than is the case. We test four variants of the hypothesis, which differ depending on whether the virtual world, the mirror, or both are taken to be rotated. We devised an experimental setup that allowed us to distinguish between these variants. Our results confirm that the virtual world--and only the virtual world--is being rotated. Observers had to perform a localization task, using a mirror that was either fronto-parallel or rotated opposite the direction of the predicted effect. We were thus able to compensate for the effect. The positions of objects in mirrors were perceived in accordance with the erroneous conception that the virtual world behind the mirror is slightly rotated and that the reconstruction is based on the non-rotated fronto-parallel mirror. A covert rotation of the mirror by about 2 degrees against the predicted effect was able to compensate for the placement error.

  11. Single Crystal Silicon Mirrors for Spaceflight Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a well understood process for manufacturing visible quality SCSi mirrors. Areas of research include stress relief, figure, finish, and light weighting...

  12. Special topics reports for the reference tandem mirror fusion breeder. Volume 5. Neutronic issues and optimization

    International Nuclear Information System (INIS)

    Lee, J.D.; Bandini, B.R.

    1985-01-01

    More rigorous nuclear analysis, including the treatment of resonance self-shielding effects coupled with an optimization procedure, has resulted in improved performance of the Be/Li/Th blanket. Net U-233 breeding ratio has increased 36% (to 0.84) while at a U/Th ratio of 0.25 a/o energy multiplication has increased 12% (to 2.1) compared with earlier results

  13. Structural support of a yin-yang magnet for a tandem mirror reactor with thermal barriers

    International Nuclear Information System (INIS)

    Erickson, J.L.; Ojalvo, I.U.; Myall, J.O.

    1980-01-01

    This report contains a comprehensive summary covering work performed by Grumman Aerospace Corporation, in conjunction with the Lawrence Livermore National Laboratory, on the TMP yin-yang coils. The yin-yang coil pair used for our analysis has a major arc radius of 2.7 m and a minor arc radius of 1.18 m, compared with 2.5 m and 0.75 m for the MFTF. The maximum field on the present conductor is 9.05 Tesla. This magnetic field is created by, and interacts with, a conductor current which produces a 360 million Newton total force, tending to separate the parallel lobes of the major arcs

  14. Special topics reports for the reference tandem mirror fusion breeder. Volume 5. Neutronic issues and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.D.; Bandini, B.R.

    1985-03-29

    More rigorous nuclear analysis, including the treatment of resonance self-shielding effects coupled with an optimization procedure, has resulted in improved performance of the Be/Li/Th blanket. Net U-233 breeding ratio has increased 36% (to 0.84) while at a U/Th ratio of 0.25 a/o energy multiplication has increased 12% (to 2.1) compared with earlier results.

  15. Recent experimental progress in the TMX-U thermal barrier tandem mirror experiment

    International Nuclear Information System (INIS)

    Turner, W.C.; Allen, S.L.; Casper, T.A.

    1984-01-01

    Recent experiments on the TMX-U thermal barrier device at LLNL have achieved the end plugging of axial ion losses up to a central cell density of n/sub c/ = 2 x 10 12 cm. During these tests, the axial potential profile characteristic of a thermal barrier has been measured experimentally, indicating an ion-confining potential greater than 1.5 kV and a potential depression of 0.45 kV in the barrier region. The average beta of hot electrons in the thermal barrier has been increased to 15% and appears limited only by classical scattering and ECRH pulse duration. Furthermore, deuterium ions in the central cell have been heated with ICRF to an average energy of 1.5 keV, with a heating efficiency of 40%. During strong end plugging, the axial ion confinement time reached 50 to 100 ms while the nonambipolar radial ion confinement time was 5 to 15 ms - independent of end plugging. Radial ion confinement time exceeding 100 ms has been attained on shots without end plugging. Plates, floated electrically on the end walls, have increased the radial ion confinement time by a factor of 1.8. Further improvement in the central cell density during end plugging can be expected by increasing the ICRF, improving the central cell vacuum conditions and beam heating efficiency, and increasing the radial extent of the potential control plates on the end walls

  16. The tandem mirror experiment upgrade (TMX-U) diagnostics data system

    International Nuclear Information System (INIS)

    Clauser, J.F.; Parrish, C.P.

    1983-01-01

    The diagnostics data system on the TMX-U experiment is a general purpose system for handling acquisition, processing, archiving, interactive selection and retrieval, and graphical and tabular outputting of data for pulsed controlled thermonuclear reaction experiments. It routinely acquires and processes three MBytes of data per shot at an average shot rate of one per 8 minutes. The computer hardware consists of five CPUs in a star configuration with approximately 500 MBytes of disk storage at the central node, upon which all CPUs may read and write. The use of several CPUs in parallel increases computing power, while the use of eight disk drives in parallel increases disk speed. All processing, outputting, and acquisition are performed by program modules that allow chained operations, i.e., the inputs for a given task (program execution) are the output(s) of a previous task or tasks. Inputs may be any data-set on disk. Tasks for various shots may overlap so that high priority results are immediately available, while low priority results may backlog and catch up during lulls in experiment operation. Task selection is thus both data-availability and priority driven. It is done in a distributed fashion, independently by each of the five CPUs (not master-slave). A given task will run on any available, suitable CPU. CPU suitability is determined using a device resource control system. Program resource requirements, task definitions, task lists, etc., as well as permanent definitions of all archived data-set configurations and symbols are saved using a commercial data-base system and custom editor, which form a data-system ''notebook''. The actual data are held in a custom data base with a hybrid relational/hierarchical form. Data-set formats are selectable from a rich, yet standardized set that can accommodate a large variety of acquired or calculated data

  17. Physics parameter calculations for a Tandem Mirror Reactor with thermal barriers

    International Nuclear Information System (INIS)

    Boghosian, B.M.; Lappa, D.A.; Logan, B.G.

    1979-01-01

    Thermal barriers are localized reductions in potential between the plugs and the central cell, which effectively insulate trapped plug electrons from the central cell electrons. By then applying electron heating in the plug, it is possible to obtain trapped electron temperatures that are much greater than those of the central cell electrons. This, in turn, effects an increase in the plug potential and central cell confinement with a concomitant decrease in plug density and injection power. Ions trapped in the barrier by collisions are removed by the injection of neutral beams directed inside the barrier cell loss cone; these beam neutrals convert trapped barrier ions to neutrals by charge exchange permitting their escape. We describe a zero-dimensional physics model for this type of reactor, and present some preliminary results for Q

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

    Science.gov (United States)

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

    2016-10-01

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

  19. Temperature measurement of an axisymmetric flame using phase shift holographic interferometry with fast Fourier transform

    Science.gov (United States)

    Tieng, S. M.; Lai, W. Z.

    Because of the importance of the temperature scalar measurements in combination diagonostics, application of phase shift holographic interferometry to temperature measurement of an axisymmetrically premixed flame was experimentally investigated. The test apparatus is an axisymmetric Bunsen burner. Propane of 99 percent purity is used as the gaseous fuel. A fast Fourier transform, a more efficient and accurate approach for Abel inversion, is used for reconstructed the axisymmetric temperature field from the interferometric data. The temperature distribution is compared with the thermocouple-measured values. The comparison shows that the proposed technique is satisfactory. The result errors are analyzed in detail. It is shown that this technique overcomes most of the earlier problems and limitations detrimental to the conventional holographic interferometry.

  20. Linac postaccelerators for tandem machines

    International Nuclear Information System (INIS)

    Jaeschke, E.

    1984-01-01

    Linear accelerators as postaccelerators have become an accepted total for increasing the final energy of tandem accelerators. This special application of linacs requires an extreme flexibility to cope with a wide velocity and specific charge range of ions while maintaining the excellent beam quality of the electrostatic machines. These requirements can best be fulfilled by choosing independently phased accelerator resonators of the spiral, splitring or quarter wave type in either normal or superconducting technology. Basic design considerations for postaccelerators are discussed and a survey about the major projects, operational or planned, is given. (orig.)

  1. Plasma confinement apparatus using solenoidal and mirror coils

    International Nuclear Information System (INIS)

    Fowler, T.K.; Condit, W.C.

    1979-01-01

    A plasma confinement apparatus is described, wherein multiple magnetic mirror cells are linked by magnetic field lines inside of a solenoid with the mirroring regions for adjacent magnetic mirror cells each formed by a separate mirror coil inside of the solenoid. The magnetic mirror cells may be field reversed

  2. Mirrors, Mirrors on the Wall...The Ubiquitous Multiple Reflection Error

    Science.gov (United States)

    Lawson, Rebecca

    2012-01-01

    Participants decided when somebody, Janine, could see their face in a horizontal row of adjacent mirrors mounted flat on the same wall. They saw real mirrors and a shop-dummy representing Janine. Such coplanar mirrors reflect different, non-overlapping areas of a scene. However, almost everybody made an unexpected error: they claimed that Janine…

  3. Non-axisymmetric line-driven disc winds - I. Disc perturbations

    Science.gov (United States)

    Dyda, Sergei; Proga, Daniel

    2018-04-01

    We study mass outflows driven from accretion discs by radiation pressure due to spectral lines. To investigate non-axisymmetric effects, we use the ATHENA++ code and develop a new module to account for radiation pressure driving. In 2D, our new simulations are consistent with previous 2D axisymmetric solutions by Proga et al., who used the ZEUS 2D code. Specifically, we find that the disc winds are time dependent, characterized by a dense stream confined to ˜45° relative to the disc mid-plane and bounded on the polar side by a less dense, fast stream. In 3D, we introduce a vertical, ϕ-dependent, subsonic velocity perturbation in the disc mid-plane. The perturbation does not change the overall character of the solution but global outflow properties such as the mass, momentum, and kinetic energy fluxes are altered by up to 100 per cent. Non-axisymmetric density structures develop and persist mainly at the base of the wind. They are relatively small, and their densities can be a few times higher than the azimuthal average. The structure of the non-axisymmetric and axisymmetric solutions differ also in other ways. Perhaps most importantly from the observational point of view are the differences in the so-called clumping factors, that serve as a proxy for emissivity due to two body processes. In particular, the spatially averaged clumping factor over the entire fast stream, while it is of a comparable value in both solutions, it varies about 10 times faster in the non-axisymmetric case.

  4. Flow of Polymer Melts in Plane- and Axi-symmetric Converging Dies

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Linding; Kjær, Erik Michael; Haudrum, Jan

    1997-01-01

    The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in all...... cases. The extensional viscous description used is the one proposed by Cogswell (3). The extensional viscosities in the two now different flow fields ate compared. The plane-symmetric extensional viscosity is found to be larger than the axi-symmetric for the HDPE melt. The two viscosities are comparable...

  5. Mirror matter and primordial black holes

    OpenAIRE

    Bell, Nicole F.; Volkas, Raymond R.

    1998-01-01

    A consequence of the evaporation of primordial black holes in the early universe may be the generation of mirror matter. This would have implications with regard to dark matter, and the number of light particle species in equilibrium at the time of big bang nucleosynthesis. The possibilities for the production of mirror matter by this mechanism are explored.

  6. LED structure with enhanced mirror reflectivity

    Science.gov (United States)

    Bergmann, Michael; Donofrio, Matthew; Heikman, Sten; Schneider, Kevin S; Haberern, Kevin W; Edmond, John A

    2014-04-01

    Embodiments of the present invention are generally related to LED chips having improved overall emission by reducing the light-absorbing effects of barrier layers adjacent mirror contacts. In one embodiment, a LED chip comprises one or more LEDs, with each LED having an active region, a first contact under the active region having a highly reflective mirror, and a barrier layer adjacent the mirror. The barrier layer is smaller than the mirror such that it does not extend beyond the periphery of the mirror. In another possible embodiment, an insulator is further provided, with the insulator adjacent the barrier layer and adjacent portions of the mirror not contacted by the active region or by the barrier layer. In yet another embodiment, a second contact is provided on the active region. In a further embodiment, the barrier layer is smaller than the mirror such that the periphery of the mirror is at least 40% free of the barrier layer, and the second contact is below the first contact and accessible from the bottom of the chip.

  7. Cortical mechanisms of mirror therapy after stroke.

    Science.gov (United States)

    Rossiter, Holly E; Borrelli, Mimi R; Borchert, Robin J; Bradbury, David; Ward, Nick S

    2015-06-01

    Mirror therapy is a new form of stroke rehabilitation that uses the mirror reflection of the unaffected hand in place of the affected hand to augment movement training. The mechanism of mirror therapy is not known but is thought to involve changes in cerebral organization. We used magnetoencephalography (MEG) to measure changes in cortical activity during mirror training after stroke. In particular, we examined movement-related changes in the power of cortical oscillations in the beta (15-30 Hz) frequency range, known to be involved in movement. Ten stroke patients with upper limb paresis and 13 healthy controls were recorded using MEG while performing bimanual hand movements in 2 different conditions. In one, subjects looked directly at their affected hand (or dominant hand in controls), and in the other, they looked at a mirror reflection of their unaffected hand in place of their affected hand. The movement-related beta desynchronization was calculated in both primary motor cortices. Movement-related beta desynchronization was symmetrical during bilateral movement and unaltered by the mirror condition in controls. In the patients, movement-related beta desynchronization was generally smaller than in controls, but greater in contralesional compared to ipsilesional motor cortex. This initial asymmetry in movement-related beta desynchronization between hemispheres was made more symmetrical by the presence of the mirror. Mirror therapy could potentially aid stroke rehabilitation by normalizing an asymmetrical pattern of movement-related beta desynchronization in primary motor cortices during bilateral movement. © The Author(s) 2014.

  8. LHCb ring imaging Cherenkov detector mirrors

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In a large dark room, men in white move around an immense structure some 7 m high, 10 m wide and nearly 2.5 m deep. Apparently effortlessly, they are installing the two large high-precision spherical mirrors. These mirrors will focus Cherenkov light, created by the charged particles that will traverse this detector, onto the photon detectors.

  9. Do mirror neurons subserve action understanding?

    Science.gov (United States)

    Hickok, Gregory

    2013-04-12

    Mirror neurons were once widely believed to support action understanding via motor simulation of the observed actions. Recent evidence regarding the functional properties of mirror neurons in monkeys as well as much neuropsychological evidence in humans has shown that this is not the case. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Unbroken Mirror Neurons in Autism Spectrum Disorders

    Science.gov (United States)

    Fan, Yang-Teng; Decety, Jean; Yang, Chia-Yen; Liu, Ji-Lin; Cheng, Yawei

    2010-01-01

    Background: The "broken mirror" theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. Methods: In this electroencephalographic…

  11. Through the one-way mirror.

    NARCIS (Netherlands)

    van Heerden, J.; Hoogstraten, J.

    1981-01-01

    Three experiments tested how the presence of a one-way mirror raises feelings of vulnerability and test anxiety. In Exp I, 37 male undergraduates performed 5 tasks measuring social desirability, personal history, and ethics either in front of a one-way mirror or not. Exp II duplicated Exp I, but

  12. 130-nm tunable grating-mirror VCSEL

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2014-01-01

    We have reported that a combination of the high-index-contrast grating (HCG) mirror as movable mirror and the extended cavity configuration with an antireflection layer can provide a tuning wavelength range of 100 nm for tunable VCSELs. Here, we report that using the air-coupled cavity...

  13. Reflecting on Reflections : Cinema's Complex Mirror Shots

    NARCIS (Netherlands)

    Hanich, Julian; Beugnet, Martine; Cameron, Allan; Fetveit, Arild

    2017-01-01

    This article investigates the effects mirrors in films can have on the composition of a filmic image, the staging of a scene and the viewing activities of the spectators. It discusses four such effects: (1) So-called ‘complex mirror shots’ can modify how spectators look onto the picture as a flat

  14. Do Mirror Neurons Subserve Action Understanding?

    OpenAIRE

    Hickok, Gregory

    2012-01-01

    Mirror neurons were once widely believed to support action understanding via motor simulation of the observed actions. Recent evidence regarding the functional properties of mirror neurons in monkeys as well as much neuropsychological evidence in humans has shown that this is not the case

  15. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  16. Where do mirror neurons come from?

    Science.gov (United States)

    Heyes, Cecilia

    2010-03-01

    Debates about the evolution of the 'mirror neuron system' imply that it is an adaptation for action understanding. Alternatively, mirror neurons may be a byproduct of associative learning. Here I argue that the adaptation and associative hypotheses both offer plausible accounts of the origin of mirror neurons, but the associative hypothesis has three advantages. First, it provides a straightforward, testable explanation for the differences between monkeys and humans that have led some researchers to question the existence of a mirror neuron system. Second, it is consistent with emerging evidence that mirror neurons contribute to a range of social cognitive functions, but do not play a dominant, specialised role in action understanding. Finally, the associative hypothesis is supported by recent data showing that, even in adulthood, the mirror neuron system can be transformed by sensorimotor learning. The associative account implies that mirror neurons come from sensorimotor experience, and that much of this experience is obtained through interaction with others. Therefore, if the associative account is correct, the mirror neuron system is a product, as well as a process, of social interaction. (c) 2009 Elsevier Ltd. All rights reserved.

  17. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  18. Folded tandem ion accelerator facility at Trombay

    Indian Academy of Sciences (India)

    Keywords. Folded tandem ion accelerator; carbon beam; magnets; electrostatic deflector; quadrupole lenses; foil/gas strippers; Rutherford back scattering. Abstract. The folded tandem ion accelerator (FOTIA) project at BARC has been commissioned. The analysed carbon beams of 40 nA(3+) and 25 nA(4+), at terminal ...

  19. Tandem Translation Classroom: A Case Study

    Science.gov (United States)

    Kim, Dohun; Koh, Taejin

    2018-01-01

    The transition to student-centred learning, advances in teleconferencing tools, and active international student exchange programmes have stimulated tandem learning in many parts of the world. This pedagogical model is based on a mutual language exchange between tandem partners, where each student is a native speaker in the language the…

  20. The Kyoto University tandem upgrading project

    International Nuclear Information System (INIS)

    Nakamura, Masanobu; Shimoura, Susumu; Takimoto, Kiyohiko; Sakaguchi, Harutaka; Kobayashi, Shinsaku

    1988-01-01

    A brief description on the Kyoto University tandem upgrading project. The project consists of replacing the old 5 MV tandem Van de Graaff by an 8UDH pelletron. The old pressure vessel and beam lines are used again without significant modification. The project is planned to be completed at the end of 1989. (orig.)

  1. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    M.R.H. Mandjes (Michel)

    2004-01-01

    textabstractWe examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution

  2. Optical properties of relativistic plasma mirrors.

    Science.gov (United States)

    Vincenti, H; Monchocé, S; Kahaly, S; Bonnaud, G; Martin, Ph; Quéré, F

    2014-03-11

    The advent of ultrahigh-power femtosecond lasers creates a need for an entirely new class of optical components based on plasmas. The most promising of these are known as plasma mirrors, formed when an intense femtosecond laser ionizes a solid surface. These mirrors specularly reflect the main part of a laser pulse and can be used as active optical elements to manipulate its temporal and spatial properties. Unfortunately, the considerable pressures exerted by the laser can deform the mirror surface, unfavourably affecting the reflected beam and complicating, or even preventing, the use of plasma mirrors at ultrahigh intensities. Here we derive a simple analytical model of the basic physics involved in laser-induced deformation of a plasma mirror. We validate this model numerically and experimentally, and use it to show how such deformation might be mitigated by appropriate control of the laser phase.

  3. Centimeter-scale suspended photonic crystal mirrors.

    Science.gov (United States)

    Moura, João P; Norte, Richard A; Guo, Jingkun; Schäfermeier, Clemens; Gröblacher, Simon

    2018-01-22

    Demand for lightweight, highly reflective and mechanically compliant mirrors for optics experiments has seen a significant surge. In this aspect, photonic crystal (PhC) membranes are ideal alternatives to conventional mirrors, as they provide high reflectivity with only a single suspended layer of patterned dielectric material. However, due to limitations in nanofabrication, these devices are usually not wider than 300 μm. Here we experimentally demonstrate suspended PhC mirrors spanning areas up to 10 × 10 mm 2 . We overcome limitations imposed by the size of the PhC and measure reflectivities greater than 90 % on 56 nm thick mirrors at a wavelength of 1550 nm-an unrivaled performance compared to PhC mirrors with micro scale diameters. These structures bridge the gap between nano scale technologies and macroscopic optical elements.

  4. Mirror neurons through the lens of epigenetics.

    Science.gov (United States)

    Ferrari, Pier F; Tramacere, Antonella; Simpson, Elizabeth A; Iriki, Atsushi

    2013-09-01

    The consensus view in mirror neuron research is that mirror neurons comprise a uniform, stable execution-observation matching system. In this opinion article, we argue that, in light of recent evidence, this is at best an incomplete and oversimplified view of mirror neurons, where activity is actually variable and more plastic than previously theorized. We propose an epigenetic account for understanding developmental changes in sensorimotor systems, including variations in mirror neuron activity. Although associative and genetic accounts fail to consider the complexity of genetic and nongenetic interactions, we propose a new evolutionary developmental biology (evo-devo) perspective, which predicts that environmental differences early in development should produce variations in mirror neuron response patterns, tuning them to the social environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. The rubber hand illusion in a mirror.

    Science.gov (United States)

    Bertamini, Marco; Berselli, Nausicaa; Bode, Carole; Lawson, Rebecca; Wong, Li Ting

    2011-12-01

    In the rubber hand illusion (RHI) one's hand is hidden, and a fake hand is visible. We explored the situation in which visual information was available indirectly in a mirror. In the mirror condition, compared to the standard condition (fake hand visible directly), we found no reduction of the RHI following synchronised stimulation, as measured by crossmanual pointing and by a questionnaire. We replicated the finding with a smaller mirror that prevented visibility of the face. The RHI was eliminated when a wooden block replaced the fake hand, or when the hand belonged to another person or mannequin. We conclude that awareness of the reflection is the critical variable, despite the distant visual localisation of the hand in a mirror and the third-person perspective. Stimuli seen in a mirror activate the same response as stimuli seen in peripersonal space, through knowledge that they are near one's body. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. DAMA annual modulation and mirror Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Cerulli, R.; Cappella, F. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Villar, P. [Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Saragossa (Spain); Laboratorio Subterraneo de Canfranc, Canfranc Estacion, Huesca (Spain); Bernabei, R.; Belli, P. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN ' ' Tor Vergata' ' , Rome (Italy); Incicchitti, A. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); INFN, Rome (Italy); Addazi, A.; Berezhiani, Z. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Universita di L' Aquila, Dipartimento di Scienze Fisiche e Chimiche, Coppito, AQ (Italy)

    2017-02-15

    The DAMA experiment using ultra low background NaI(Tl) crystal scintillators has measured an annual modulation effect in the keV region which satisfies all the peculiarities of an effect induced by Dark Matter particles. In this paper we analyze this annual modulation effect in terms of mirror Dark Matter, an exact duplicate of ordinary matter from parallel hidden sector, which chemical composition is dominated by mirror helium while it can also contain significant fractions of heavier elements as Carbon and Oxygen. Dark mirror atoms are considered to interact with the target nuclei in the detector via Rutherford-like scattering induced by kinetic mixing between mirror and ordinary photons, both being massless. In the present analysis we consider various possible scenarios for the mirror matter chemical composition. For all the scenarios, the relevant ranges for the kinetic mixing parameter have been obtained taking also into account various existing uncertainties in nuclear and particle physics quantities. (orig.)

  7. Mirror neurons and their clinical relevance.

    Science.gov (United States)

    Rizzolatti, Giacomo; Fabbri-Destro, Maddalena; Cattaneo, Luigi

    2009-01-01

    One of the most exciting events in neurosciences over the past few years has been the discovery of a mechanism that unifies action perception and action execution. The essence of this 'mirror' mechanism is as follows: whenever individuals observe an action being done by someone else, a set of neurons that code for that action is activated in the observers' motor system. Since the observers are aware of the outcome of their motor acts, they also understand what the other individual is doing without the need for intermediate cognitive mediation. In this Review, after discussing the most pertinent data concerning the mirror mechanism, we examine the clinical relevance of this mechanism. We first discuss the relationship between mirror mechanism impairment and some core symptoms of autism. We then outline the theoretical principles of neurorehabilitation strategies based on the mirror mechanism. We conclude by examining the relationship between the mirror mechanism and some features of the environmental dependency syndromes.

  8. Mirror-image-induced magnetic modes.

    Science.gov (United States)

    Xifré-Pérez, Elisabet; Shi, Lei; Tuzer, Umut; Fenollosa, Roberto; Ramiro-Manzano, Fernando; Quidant, Romain; Meseguer, Francisco

    2013-01-22

    Reflection in a mirror changes the handedness of the real world, and right-handed objects turn left-handed and vice versa (M. Gardner, The Ambidextrous Universe, Penguin Books, 1964). Also, we learn from electromagnetism textbooks that a flat metallic mirror transforms an electric charge into a virtual opposite charge. Consequently, the mirror image of a magnet is another parallel virtual magnet as the mirror image changes both the charge sign and the curl handedness. Here we report the dramatic modification in the optical response of a silicon nanocavity induced by the interaction with its image through a flat metallic mirror. The system of real and virtual dipoles can be interpreted as an effective magnetic dipole responsible for a strong enhancement of the cavity scattering cross section.

  9. Beam shaping for relay mirrors

    Science.gov (United States)

    Mansell, Justin D.

    2006-08-01

    Relay mirrors offer a method of extending the range and efficacy of laser weapons systems by providing a platform that can relay the high power beam from the source to a target at a lower cost than building more laser weapons. Most laser weapons' platforms use a Cassegrain aperture telescope to project the high-power beam to a target. Diffraction causes power in the projected beam to move out beyond the edge of the receiving aperture and into the central obscuration of the receiving Cassegrain telescope. This paper presents a method of increasing the power coupling between a projected beam and a receiving telescope by warping the phase of the projected beam and shows that the spatial frequency and amplitude of the phase aberration is consistent with being integrated with the adaptive optics control loop on the source beam projector.

  10. Durable silver coating for mirrors

    Science.gov (United States)

    Wolfe, Jesse D.; Thomas, Norman L.

    2000-01-01

    A durable multilayer mirror includes reflective layers of aluminum and silver and has high reflectance over a broad spectral range from ultraviolet to visible to infrared. An adhesion layer of a nickel and/or chromium alloy or nitride is deposited on an aluminum surface, and a thin layer of silver is then deposited on the adhesion layer. The silver layer is protected by a passivation layer of a nickel and/or chromium alloy or nitride and by one or more durability layers made of metal oxides and typically a first layer of metal nitride. The durability layers may include a composite silicon aluminum nitride and an oxinitride transition layer to improve bonding between nitride and oxide layers.

  11. Durable silver coating for mirrors

    International Nuclear Information System (INIS)

    Wolfe, J.D.; Thomas, N.L.

    2000-01-01

    A durable multilayer mirror includes reflective layers of aluminum and silver and has high reflectance over a broad spectral range from ultraviolet to visible to infrared. An adhesion layer of a nickel and/or chromium alloy or nitride is deposited on an aluminum surface, and a thin layer of silver is then deposited on the adhesion layer. The silver layer is protected by a passivation layer of a nickel and/or chromium alloy or nitride and by one or more durability layers made of metal oxides and typically a first layer of metal nitride. The durability layers may include a composite silicon aluminum nitride and an oxinitride transition layer to improve bonding between nitride and oxide layers

  12. Mirror neurons: from origin to function.

    Science.gov (United States)

    Cook, Richard; Bird, Geoffrey; Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2014-04-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively observes a similar action performed by another agent. It is widely believed that mirror neurons are a genetic adaptation for action understanding; that they were designed by evolution to fulfill a specific socio-cognitive function. In contrast, we argue that mirror neurons are forged by domain-general processes of associative learning in the course of individual development, and, although they may have psychological functions, they do not necessarily have a specific evolutionary purpose or adaptive function. The evidence supporting this view shows that (1) mirror neurons do not consistently encode action "goals"; (2) the contingency- and context-sensitive nature of associative learning explains the full range of mirror neuron properties; (3) human infants receive enough sensorimotor experience to support associative learning of mirror neurons ("wealth of the stimulus"); and (4) mirror neurons can be changed in radical ways by sensorimotor training. The associative account implies that reliable information about the function of mirror neurons can be obtained only by research based on developmental history, system-level theory, and careful experimentation.

  13. Archetypal-Imaging and Mirror-Gazing

    Science.gov (United States)

    Caputo, Giovanni B.

    2013-01-01

    Mirrors have been studied by cognitive psychology in order to understand self-recognition, self-identity, and self-consciousness. Moreover, the relevance of mirrors in spirituality, magic and arts may also suggest that mirrors can be symbols of unconscious contents. Carl G. Jung investigated mirrors in relation to the unconscious, particularly in Psychology and Alchemy. However, the relationship between the conscious behavior in front of a mirror and the unconscious meaning of mirrors has not been clarified. Recently, empirical research found that gazing at one’s own face in the mirror for a few minutes, at a low illumination level, produces the perception of bodily dysmorphic illusions of strange-faces. Healthy observers usually describe huge distortions of their own faces, monstrous beings, prototypical faces, faces of relatives and deceased, and faces of animals. In the psychiatric population, some schizophrenics show a dramatic increase of strange-face illusions. They can also describe the perception of multiple-others that fill the mirror surface surrounding their strange-face. Schizophrenics are usually convinced that strange-face illusions are truly real and identify themselves with strange-face illusions, diversely from healthy individuals who never identify with them. On the contrary, most patients with major depression do not perceive strange-face illusions, or they perceive very faint changes of their immobile faces in the mirror, like death statues. Strange-face illusions may be the psychodynamic projection of the subject’s unconscious archetypal contents into the mirror image. Therefore, strange-face illusions might provide both an ecological setting and an experimental technique for “imaging of the unconscious”. Future researches have been proposed. PMID:25379264

  14. Archetypal-Imaging and Mirror-Gazing

    Directory of Open Access Journals (Sweden)

    Giovanni B. Caputo

    2013-12-01

    Full Text Available Mirrors have been studied by cognitive psychology in order to understand self-recognition, self-identity, and self-consciousness. Moreover, the relevance of mirrors in spirituality, magic and arts may also suggest that mirrors can be symbols of unconscious contents. Carl G. Jung investigated mirrors in relation to the unconscious, particularly in Psychology and Alchemy. However, the relationship between the conscious behavior in front of a mirror and the unconscious meaning of mirrors has not been clarified. Recently, empirical research found that gazing at one’s own face in the mirror for a few minutes, at a low illumination level, produces the perception of bodily dysmorphic illusions of strange-faces. Healthy observers usually describe huge distortions of their own faces, monstrous beings, prototypical faces, faces of relatives and deceased, and faces of animals. In the psychiatric population, some schizophrenics show a dramatic increase of strange-face illusions. They can also describe the perception of multiple-others that fill the mirror surface surrounding their strange-face. Schizophrenics are usually convinced that strange-face illusions are truly real and identify themselves with strange-face illusions, diversely from healthy individuals who never identify with them. On the contrary, most patients with major depression do not perceive strange-face illusions, or they perceive very faint changes of their immobile faces in the mirror, like death statues. Strange-face illusions may be the psychodynamic projection of the subject’s unconscious archetypal contents into the mirror image. Therefore, strange-face illusions might provide both an ecological setting and an experimental technique for “imaging of the unconscious”. Future researches have been proposed.

  15. Numerical analyses of radiative heat transfer in any arbitrarily-shaped axisymmetric enclosures

    International Nuclear Information System (INIS)

    Ben Salah, M.; Askri, F; Jemni, A.; Nasrallah, S. Ben

    2006-01-01

    A numerical approach for the treatment of radiative heat transfer in any irregularly-shaped axisymmetric enclosure filled with absorbing, emitting and scattering gray media is developed. Radiative transfer equation (RTE) is formulated for a general axisymmetric geometrical configurations, and the discretized equation is conducted using an unstructured meshes, generated by an appropriate computer algorithm, and the control volume finite element method which frequently adopted in CFD problems. A computer procedure has been done to solve the discretized RTE and to examine the accuracy and the computational efficiency of the proposed numerical approach. By using this computer algorithm, five test cases, a cylindrical enclosure with absorbing and emitting medium, a diffuser shaped axisymmetric enclosure, a finite axisymmetric cylindrical enclosure with a curved wall, a furnace with axially varying medium temperature and a rocket nozzle, are treated and the obtained results agree very well with other published works. Furthermore, the developed computer procedure has an accurate CPU time and it can be coupled easily with CFD codes

  16. Axi-Symmetric Simulation of the Slump Flow Test for Self-Compacting

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm; Szabo, Peter; Geiker, Mette Rica

    2004-01-01

    . This paper presents a numerical axi-symmetric approach for simulation of the slump flow test. Simulations are compared to experimental test results on the rheological properties and slump flow. Former rheological investigations on SCC indicate a non-Newtonian behaviour according to the Bingham model....

  17. Flow of Polymer Melts in Plane- and Axi-symmetric Converging Dies

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Linding; Kjær, Erik Michael; Haudrum, Jan

    1997-01-01

    The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in all...

  18. Studying the coupled eigenoscillations of an axisymmetric tower-elevated tank system by the multimodal method

    Science.gov (United States)

    Gavrilyuk, I.; Hermann, M.; Trotsenko, Yu.; Timokha, A.

    2013-10-01

    Employing the virtual work variational principle and the linear multimodal method for the liquid sloshing in an axisymmetric tank, we study coupled eigenoscillations of a tower and an elevated tank partially filled by a liquid. An emphasis is placed on the case of an upright circular cylindrical tank. Theoretical results are compared with known experimental data.

  19. Dynamic analysis of reactor containment building using axisymmetric finite element model

    International Nuclear Information System (INIS)

    Thakkar, S.K.; Dubey, R.N.

    1989-01-01

    The structural safety of nuclear reactor building during earthquake is of great importance in view of possibility of radiation hazards. The rational evaluation of forces and displacements in various portions of structure and foundation during strong ground motion is most important for safe performance and economic design of the reactor building. The accuracy of results of dynamic analysis is naturally dependent on the type of mathematical model employed. Three types of mathematical models are employed for dynamic analysis of reactor building beam model axisymmetric finite element model and three dimensional model. In this paper emphasis is laid on axisymmetric model. This model of containment building is considered a reinfinement over conventional beam model of the structure. The nuclear reactor building on a rocky foundation is considered herein. The foundation-structure interaction is relatively less in this condition. The objective of the paper is to highlight the significance of modelling of non-axisymmetric portion of building, such as reactor internals by equivalent axisymmetric body, on the structural response of the building

  20. ASSESSMENT OF BACTERIAL BIOSURFACTANT PRODUCTION THROUGH AXISYMMETRICAL DROP SHAPE-ANALYSIS BY PROFILE

    NARCIS (Netherlands)

    VANDERVEGT, W; VANDERMEI, HC; BUSSCHER, HJ

    Axisymmetric drop shape analysis by profile (ADSA-P) is a technique developed in colloid and surface science to simultaneously determine the contact angle and liquid surface tension from the profile of a droplet resting on a solid surface. In this paper is described how ADSA-P can be employed to

  1. Low-frequency behavior of the turbulent axisymmetric near-wake

    NARCIS (Netherlands)

    Gentile, V.; Schrijer, F.F.J.; van Oudheusden, B.W.; Scarano, F.

    2016-01-01

    The turbulent wake past an axisymmetric body is investigated with time-resolved stereoscopic particle image velocimetry (PIV) at a Reynolds number ReD = 6.7 × 104 based on the object diameter. The azimuthal organization of the near-wake is studied at different locations downstream of the trailing

  2. Experimental investigation into the unsteady effects on non-axisymmetric turbine endwall contouring

    CSIR Research Space (South Africa)

    Dunn, Dwain I

    2010-01-01

    Full Text Available Turbine manufacturers are striving to develop turbines that are more efficient. One area of focus has been the control of secondary flows through the use of non-axisymmetric endwalls. The majority of development has been performed in cascades...

  3. Corrections and comments on the multipole moments of axisymmetric electrovacuum spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Sotiriou, Thomas P; Apostolatos, Theocharis A [Section of Astrophysics, Astronomy, and Mechanics Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15783, Athens (Greece)

    2004-12-21

    Following the method of Hoenselaers and Perjes, we present a new corrected and dimensionally consistent set of multipole gravitational and electromagnetic moments for stationary axisymmetric spacetimes. Furthermore, we use our results to compute the multipole moments, both gravitational and electromagnetic, of a Kerr-Newman black hole.

  4. Electromagnetic Simulations for an Axisymmetric Gregorian Reflector System for a Space Deployed Inflatable Antenna

    Science.gov (United States)

    2016-01-22

    Electromagnetic Simulations for an Axisymmetric Gregorian Reflector System for a Space-Deployed Inflatable Antenna Alan J. Fenn Lincoln...system for potential space deployment is explored. The antenna utilizes a planar array located near the vertex of the primary reflector. Numerical...electromagnetic simulations based on the multilevel fast multipole method (MLFMM) were used to analyze and optimize the antenna parameters for

  5. Flow of Polymer Melts in Plane- and Axi-Symmetric Converging Dies

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Linding; Kjær, Erik Michael; Haudrum, Jan

    1998-01-01

    The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in al...

  6. Status of JAERI tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi; Kanda, Susumu; Takeuchi, Suehiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] (and others)

    2001-02-01

    JAERI Tandem Accelerator had been operated approximately 230 days in fiscal year of 1999. Meanwhile, we had three times of maintenance period with vent. Total operation-times were 5273 hours. We could not carry out the experiment using rare gas, due to malfunction of the RF power supply for the ECR ion source. The type of the RF power supply is peculiar and it is impossible to get spare parts for repair. We are now investigating the backup RF power supply. The power supply for the magnet became unstable due to degradation of insulation in the shunt resistance, which is used for feedback stabilization. Stability was recovered after cleaning. The acrylic resin shaft was cracked. This cracks have a potential for severe accidents. So far bearing of the shaft has no problem. The reason of cracks may be self-destruction by charge accumulation in the shaft. JAERI Tandem Accelerator is approximately 20 years old. There appear requirements on the higher ion currents for additional ion species. Therefore, authors are investigating cost effective improvement plans of RFQ (Radio Frequency Quadra-pole) and IH type accelerator based on KEK (High Energy Accelerator Research Organization) R and D. As a whole, maintenance services for the control system are increasing due to some changes of computer programs. There are some difficulties to keep skilled personnel for facilities operation. Authors are gradually increasing hired personnel with contract from 1993. However, loads for JAERI permanent staffs are still heavy. It takes much longer time to educate skilled persons especially for safety. (Y. Tanaka)

  7. Mirror neurons: functions, mechanisms and models.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael A

    2013-04-12

    Mirror neurons for manipulation fire both when the animal manipulates an object in a specific way and when it sees another animal (or the experimenter) perform an action that is more or less similar. Such neurons were originally found in macaque monkeys, in the ventral premotor cortex, area F5 and later also in the inferior parietal lobule. Recent neuroimaging data indicate that the adult human brain is endowed with a "mirror neuron system," putatively containing mirror neurons and other neurons, for matching the observation and execution of actions. Mirror neurons may serve action recognition in monkeys as well as humans, whereas their putative role in imitation and language may be realized in human but not in monkey. This article shows the important role of computational models in providing sufficient and causal explanations for the observed phenomena involving mirror systems and the learning processes which form them, and underlines the need for additional circuitry to lift up the monkey mirror neuron circuit to sustain the posited cognitive functions attributed to the human mirror neuron system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Laser cleaning of ITER's diagnostic mirrors

    Science.gov (United States)

    Skinner, C. H.; Gentile, C. A.; Doerner, R.

    2012-10-01

    Practical methods to clean ITER's diagnostic mirrors and restore reflectivity will be critical to ITER's plasma operations. We report on laser cleaning of single crystal molybdenum mirrors coated with either carbon or beryllium films 150 - 420 nm thick. A 1.06 μm Nd laser system provided 220 ns pulses at 8 kHz with typical power densities of 1-2 J/cm^2. The laser beam was fiber optically coupled to a scanner suitable for tokamak applications. The efficacy of mirror cleaning was assessed with a new technique that combines microscopic imaging and reflectivity measurements [1]. The method is suitable for hazardous materials such as beryllium as the mirrors remain sealed in a vacuum chamber. Excellent restoration of reflectivity for the carbon coated Mo mirrors was observed after laser scanning under vacuum conditions. For the beryllium coated mirrors restoration of reflectivity has so far been incomplete and modeling indicates that a shorter duration laser pulse is needed. No damage of the molybdenum mirror substrates was observed.[4pt][1] C.H. Skinner et al., Rev. Sci. Instrum. at press.

  9. Mirror dark matter and large scale structure

    International Nuclear Information System (INIS)

    Ignatiev, A.Yu.; Volkas, R.R.

    2003-01-01

    Mirror matter is a dark matter candidate. In this paper, we reexamine the linear regime of density perturbation growth in a universe containing mirror dark matter. Taking adiabatic scale-invariant perturbations as the input, we confirm that the resulting processed power spectrum is richer than for the more familiar cases of cold, warm and hot dark matter. The new features include a maximum at a certain scale λ max , collisional damping below a smaller characteristic scale λ S ' , with oscillatory perturbations between the two. These scales are functions of the fundamental parameters of the theory. In particular, they decrease for decreasing x, the ratio of the mirror plasma temperature to that of the ordinary. For x∼0.2, the scale λ max becomes galactic. Mirror dark matter therefore leads to bottom-up large scale structure formation, similar to conventional cold dark matter, for x(less-or-similar sign)0.2. Indeed, the smaller the value of x, the closer mirror dark matter resembles standard cold dark matter during the linear regime. The differences pertain to scales smaller than λ S ' in the linear regime, and generally in the nonlinear regime because mirror dark matter is chemically complex and to some extent dissipative. Lyman-α forest data and the early reionization epoch established by WMAP may hold the key to distinguishing mirror dark matter from WIMP-style cold dark matter

  10. Plasma impact on diagnostic mirrors in JET

    Directory of Open Access Journals (Sweden)

    A. Garcia-Carrasco

    2017-08-01

    Full Text Available Metallic mirrors will be essential components of all optical systems for plasma diagnosis in ITER. This contribution provides a comprehensive account on plasma impact on diagnostic mirrors in JET with the ITER-Like Wall. Specimens from the First Mirror Test and the lithium-beam diagnostic have been studied by spectrophotometry, ion beam analysis and electron microscopy. Test mirrors made of molybdenum were retrieved from the main chamber and the divertor after exposure to the 2013–2014 experimental campaign. In the main chamber, only mirrors located at the entrance of the carrier lost reflectivity (Be deposition, while those located deeper in the carrier were only slightly affected. The performance of mirrors in the JET divertor was strongly degraded by deposition of beryllium, tungsten and other species. Mirrors from the lithium-beam diagnostic have been studied for the first time. Gold coatings were severely damaged by intense arcing. As a consequence, material mixing of the gold layer with the stainless steel substrate occurred. Total reflectivity dropped from over 90% to less than 60%, i.e. to the level typical for stainless steel.

  11. Contact analysis of the native radiocapitellar joint compared with axisymmetric and nonaxisymmetric radial head hemiarthroplasty.

    Science.gov (United States)

    Langohr, G Daniel G; Willing, Ryan; Medley, John B; King, Graham J W; Johnson, James A

    2015-05-01

    Radial head (RH) implants are manufactured from stiff materials, resulting in reduced radiocapitellar contact area that may lead to cartilage degeneration. Although the native RH is nonaxisymmetric, most implants are axisymmetric, potentially contributing to altered contact mechanics. This study compared the joint contact area (Ac) and maximum contact stress (σmax) of axisymmetric and nonaxisymmetric RH implants to the native radiocapitellar joint. The contact mechanics of intact elbows derived from cadaveric computed tomography data (n = 15) were compared with axisymmetric (size: 18, 20, 22 mm) and nonaxisymmetric (size: 16 × 18, 18 × 20, 20 × 22 mm) RH hemiarthroplasty reconstructed elbows using Abaqus finite element software. Under a 100 N load, Ac and σmax were computed for ±90° pronation-supination and 0°, 45°, 90°, and 135° flexion. Compared with native, both hemiarthroplasty models produced significantly lower Ac and higher σmax (P < .001). In the best orientation, the nonaxisymmetric RH provided significantly larger Ac at 0° and 135° flexion (P = .03, P = .007) and reduced levels of σmax at 45° and 90° flexion (P = .003, P < .001). However, there was also a worst orientation that reduced Ac and increased σmax for all flexion angles (P < .003 for all). The native RH was less sensitive to rotation than the nonaxisymmetric RH in terms of σmax (P < .001). The axisymmetric RH was not sensitive to rotation. Whereas a nonaxisymmetric RH can provide improved contact mechanics at certain forearm rotations and flexions, there are also orientations where Ac is reduced and σmax is increased. Axisymmetric designs are more consistent throughout forearm rotation and therefore may be more forgiving than the nonaxisymmetric RH implant design used in this study. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  12. Mirror and (absence of) counter-mirror responses to action sounds measured with TMS.

    Science.gov (United States)

    Ticini, Luca F; Schütz-Bosbach, Simone; Waszak, Florian

    2017-11-01

    To what extent is the mirror neuron mechanism malleable to experience? The answer to this question can help characterising its ontogeny and its role in social cognition. Some suggest that it develops through sensorimotor associations congruent with our own actions. Others argue for its extreme volatility that will encode any sensorimotor association in the environment. Here, we added to this debate by exploring the effects of short goal-directed 'mirror' and 'counter-mirror' trainings (a 'mirror' training is defined as the first type of training encountered by the participants) on human auditory mirror motor-evoked potentials (MEPs). We recorded MEPs in response to two tones void of previous motor meaning, before and after mirror and counter-mirror trainings in which participants generated two tones of different pitch by performing free-choice button presses. The results showed that mirror MEPs, once established, were protected against an equivalent counter-mirror experience: they became manifest very rapidly and the same number of training trials that lead to the initial association did not suffice to reverse the MEP pattern. This steadiness of the association argues that, by serving direct-matching purposes, the mirror mechanism is a good solution for social cognition. © The Author (2017). Published by Oxford University Press.

  13. Near-field flat focusing mirrors

    Science.gov (United States)

    Cheng, Yu-Chieh; Staliunas, Kestutis

    2018-03-01

    This article reviews recent progress towards the design of near-field flat focusing mirrors, focusing/imaging light patterns in reflection. An important feature of such flat focusing mirrors is their transverse invariance, as they do not possess any optical axis. We start with a review of the physical background to the different focusing mechanisms of near- and far-field focusing. These near-field focusing devices like flat lenses and the reviewed near-field focusing mirrors can implement planar focusing devices without any optical axis. In contrast, various types of far-field planar focusing devices, such as high-contrast gratings and metasurfaces, unavoidably break the transverse invariance due to their radially symmetrical structures. The particular realizations of near-field flat focusing mirrors including Bragg-like dielectric mirrors and dielectric subwavelength gratings are the main subjects of the review. The first flat focusing mirror was demonstrated with a chirped mirror and was shown to manage an angular dispersion for beam focusing, similar to the management of chromatic dispersion for pulse compression. Furthermore, the reviewed optimized chirped mirror demonstrated a long near-field focal length, hardly achieved by a flat lens or a planar hyperlens. Two more different configurations of dielectric subwavelength gratings that focus a light beam at normal or oblique incidence are also reviewed. We also summarize and compare focusing performance, limitations, and future perspectives between the reviewed flat focusing mirrors and other planar focusing devices including a flat lens with a negative-index material, a planar hyperlens, a high-contrast grating, and a metasurface.

  14. What We Know Currently about Mirror Neurons

    Science.gov (United States)

    Kilner, J.M.; Lemon, R.N.

    2013-01-01

    Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as “The most hyped concept in neuroscience”. Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons. PMID:24309286

  15. What we know currently about mirror neurons.

    Science.gov (United States)

    Kilner, J M; Lemon, R N

    2013-12-02

    Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as "The most hyped concept in neuroscience". Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Ultrasmooth microfabricated mirrors for quantum information

    Science.gov (United States)

    Biedermann, G. W.; Benito, F. M.; Fortier, K. M.; Stick, D. L.; Loyd, T. K.; Schwindt, P. D. D.; Nakakura, C. Y.; Jarecki, R. L.; Blain, M. G.

    2010-11-01

    In this paper, we realize a scalable micromirror suitable for atom chip based cavity quantum electrodynamics applications. A very low surface roughness of 2.2 Å rms on the silicon cavity mirrors is achieved using chemical dry etching along with plasma and oxidation smoothing. Our Fabry-Perot cavity comprised of these mirrors currently demonstrates the highest finesse, F =64 000, using microfabricated mirrors. We compute a single atom cooperativity for our cavities of more than 200, making them promising candidates for detecting individual atoms and for quantum information applications on a chip.

  17. The ontogenetic origins of mirror neurons: evidence from 'tool-use' and 'audiovisual' mirror neurons.

    Science.gov (United States)

    Cook, Richard

    2012-10-23

    Since their discovery, mirror neurons--units in the macaque brain that discharge both during action observation and execution--have attracted considerable interest. Whether mirror neurons are an innate endowment or acquire their sensorimotor matching properties ontogenetically has been the subject of intense debate. It is widely believed that these units are an innate trait; that we are born with a set of mature mirror neurons because their matching properties conveyed upon our ancestors an evolutionary advantage. However, an alternative view is that mirror neurons acquire their matching properties during ontogeny, through correlated experience of observing and performing actions. The present article re-examines frequently overlooked neurophysiological reports of 'tool-use' and 'audiovisual' mirror neurons within the context of this debate. It is argued that these findings represent compelling evidence that mirror neurons are a product of sensorimotor experience, and not an innate endowment.

  18. Europe in the Balkan mirror

    Directory of Open Access Journals (Sweden)

    Milutinović Zoran

    2015-01-01

    Full Text Available The article discusses the three dominant, Europe-wide, constructions of Europe in the nineteenth and twentieth centuries, and claims that all three found their proponents in the Balkans in the same period, while no specifically Balkan construction of Europe can be identified. The discourses which constructed Europe were transnational, and every search for national discourses must recognize that they are always fractured and contradictory, composed of various elements originating in Europe-wide discourses on Europe. Throughout this period the dominant discourse of Europe was shaped by the discourse of modernity and modernization, not only in Europe but in other parts of the globe as well. Several commentators have already noted that the current challenge of the interwar construction of Europe - peace, prosperity, democracy and human rights - mirrors the crisis of Yugoslavia, and many examples point to the unsustainability of this construction at the beginning of the twenty-first century. Gadamer’s hermeneutics offers a valuable lesson in humility and defines the oft-repeated phrase of “belonging together” as listening to the other in the belief that the other may be right, which should be taken as a starting point for any future construction of Europe.

  19. Physics of field reversed mirrors

    International Nuclear Information System (INIS)

    Post, R.F.

    1978-01-01

    Since the earliest days of fusion research it has been hoped that diamagnetic currents flowing in a plasma could be used to help confine the plasma. Recently this hope has been strengthened both by theoretical advances and by experimental results made possible by technological developments. On the theoretical front analytical treatments and computer simulation studies have demonstrated equilibrium solutions existing both in the fluid limit and in the large-orbit limit. Progress has also been made in determining the conditions required for the stability of field-reversed entities. It appears that configurations of the general form of fat doughnuts, possibly elongated to napkin-ring form, represent stable states. Building on previous experimental work, several investigators have been able to create field-reversed states. One method, based on the ASTRON idea of Christofilos, traps an intense relativistic electron beams (REB) to create a field-reversing current ring. Other approaches use either the reversed field theta pinch technique or REB pulses to create field-reversing diamagnetic currents in a long cylindrical plasma. In the former method, millisecond-long field-reversing electron rings have been achieved; in the latter method field-reversed plasma states lasting 30 to 50 microseconds have been achieved. Another approach under investigation is the Field Reversed Mirror (FRM) created by the tangential injection of high current neutral beams. Plasma states that approach field reversal have been achieved by this technique

  20. Mirror Symmetry, Hitchin's Equations, And Langlands Duality

    Science.gov (United States)

    Witten, Edward

    This chapter begins with a discussion of the A-model and B-model. It then describes mirror symmetry and Hitchin's equations, Hitchin fibration, ramification, wild ramification, and four-dimensional gauge theory and stacks.

  1. Ultra-Lightweight Hybrid Structured Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MMCC is proposing herewith a hybrid structured mirror that combines the advantages of SiC membrane and magnesium graphite composite. The significance of magnesium...

  2. Driver ASICs for Advanced Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program leverages on our extensive expertise in developing high-performance driver ASICs for deformable mirror systems and seeks to expand the capacities of the...

  3. Advanced Mirror Material System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Peregrine will bring together recent laboratory developments and mature the technology so that complete mirror and telescope assemblies can be reliably and robustly...

  4. The mirror mechanism: recent findings and perspectives

    Science.gov (United States)

    Rizzolatti, Giacomo; Fogassi, Leonardo

    2014-01-01

    Mirror neurons are a specific type of visuomotor neuron that discharge both when a monkey executes a motor act and when it observes a similar motor act performed by another individual. In this article, we review first the basic properties of these neurons. We then describe visual features recently investigated which indicate that, besides encoding the goal of motor acts, mirror neurons are modulated by location in space of the observed motor acts, by the perspective from which the others’ motor acts are seen, and by the value associated with the object on which others’ motor acts are performed. In the last part of this article, we discuss the role of the mirror mechanism in planning actions and in understanding the intention underlying the others’ motor acts. We also review some human studies suggesting that motor intention in humans may rely, as in the monkey, on the mirror mechanism. PMID:24778385

  5. The mirror mechanism in the parietal lobe.

    Science.gov (United States)

    Rizzolatti, Giacomo; Rozzi, Stefano

    2018-01-01

    The mirror mechanism is a basic mechanism that transforms sensory representations of others' actions into motor representations of the same actions in the brain of the observer. The mirror mechanism plays an important role in understanding actions of others. In the present chapter we discuss first the basic organization of the posterior parietal lobe in the monkey, stressing that it is best characterized as a motor scaffold, on the top of which sensory information is organized. We then describe the location of the mirror mechanism in the posterior parietal cortex of the monkey, and its functional role in areas PFG, and anterior, ventral, and lateral intraparietal areas. We will then present evidence that a similar functional organization is present in humans. We will conclude by discussing the role of the mirror mechanism in the recognition of action performed with tools. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Collimated Magnetron Sputter Deposition for Mirror Coatings

    DEFF Research Database (Denmark)

    Vickery, A.; Cooper-Jensen, Carsten P.; Christensen, Finn Erland

    2008-01-01

    At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence that a collimat......At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence...... that a collimation of the sputtered particles is an efficient way to suppress the interfacial roughness of the produced multilayer. We present two different types of collimation optimized for the production of low roughness curved mirrors and flat mirrors, respectively....

  7. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to undertake the initial development of a Kirkpatrick-Baez (K-B) type X-ray mirror using the relatively recent availability of high quality, inexpensive,...

  8. ADE string chains and mirror symmetry

    Science.gov (United States)

    Haghighat, Babak; Yan, Wenbin; Yau, Shing-Tung

    2018-01-01

    6d superconformal field theories (SCFTs) are the SCFTs in the highest possible dimension. They can be geometrically engineered in F-theory by compactifying on non-compact elliptic Calabi-Yau manifolds. In this paper we focus on the class of SCFTs whose base geometry is determined by -2 curves intersecting according to ADE Dynkin diagrams and derive the corresponding mirror Calabi-Yau manifold. The mirror geometry is uniquely determined in terms of the mirror curve which has also an interpretation in terms of the Seiberg-Witten curve of the four-dimensional theory arising from torus compactification. Adding the affine node of the ADE quiver to the base geometry, we connect to recent results on SYZ mirror symmetry for the A case and provide a physical interpretation in terms of little string theory. Our results, however, go beyond this case as our construction naturally covers the D and E cases as well.

  9. Advanced Mirror Material System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Peregrine will bring together recent laboratory developments and mature the technology so that complete mirror and telescope assemblies can be reliably and robustly...

  10. Reflections on mirror neurons and speech perception

    Science.gov (United States)

    Lotto, Andrew J.; Hickok, Gregory S.; Holt, Lori L.

    2010-01-01

    The discovery of mirror neurons, a class of neurons that respond when a monkey performs an action and also when the monkey observes others producing the same action, has promoted a renaissance for the Motor Theory (MT) of speech perception. This is because mirror neurons seem to accomplish the same kind of one to one mapping between perception and action that MT theorizes to be the basis of human speech communication. However, this seeming correspondence is superficial, and there are theoretical and empirical reasons to temper enthusiasm about the explanatory role mirror neurons might have for speech perception. In fact, rather than providing support for MT, mirror neurons are actually inconsistent with the central tenets of MT. PMID:19223222

  11. Mirror aneurysms : a reflection on natural history

    NARCIS (Netherlands)

    Meissner, Irene; Torner, James; Huston III, John; Rajput, Michele L.; Wiebers, David O.; Jones, Lyell K.; Brown, Robert D.; Groen, Rob

    OBJECT: Investigators conducting the International Study of Unruptured Intracranial Aneurysms, sponsored by the National Institutes of Health, sought to evaluate predictors of future hemorrhage in patients who had unruptured mirror aneurysms. These paired aneurysms in bilateral arterial positions

  12. Silicon Wafer X-ray Mirror

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to undertake the initial development of a Kirkpatrick-Baez (K-B) type X-ray mirror using the relatively recent availability of high quality, inexpensive,...

  13. Four-Mirror Freeform Reflective Imaging Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — Central Objectives: The research involves a revelation of the solution space for revolutionary families of four-mirror freeform reflective imaging systems. A...

  14. Supersymmetric defect models and mirror symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Hook, Anson; Kachru, Shamit; Torroba, Gonzalo

    2013-11-01

    We study supersymmetric field theories in three space-time dimensions doped by various configurations of electric charges or magnetic fluxes. These are supersymmetric avatars of impurity models. In the presence of additional sources such configurations are shown to preserve half of the supersymmetries. Mirror symmetry relates the two sets of configurations. We discuss the implications for impurity models in 3d NN = 4 QED with a single charged hypermultiplet (and its mirror, the theory of a free hypermultiplet) as well as 3d NN = 2 QED with one flavor and its dual, a supersymmetric Wilson-Fisher fixed point. Mirror symmetry allows us to find backreacted solutions for arbitrary arrays of defects in the IR limit of NN = 4 QED. Our analysis, complemented with appropriate string theory brane constructions, sheds light on various aspects of mirror symmetry, the map between particles and vortices and the emergence of ground state entropy in QED at finite density.

  15. Phase conjugating plasma mirror free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, A.; McMullin, W.A.

    1988-02-02

    A self-aligning, high power, free-electron laser (FEL) oscillator is described comprising: (a) a partially transmitting, stimulated Brillouin scattering (SBS) plasma mirror output element located near the output end of the FEL wiggler for reflecting a portion of the radiation emitted by the FEL wiggler back through the wiggler; (b) a self-aligning, feedback element located near the electron beam input end of the FEL wiggler for reflecting the portion of radiation from the output element back through the FEL wiggler; (c) laser beam expansion elements in succession on the path of the resulting output laser beam for magnifying the laser beam to a desired output diameter; and (d) a totally reflecting, removable start-up mirror located between the SBS plasma mirror and the laser beam expansion elements, the removable start-up mirror for providing feedback until the SBS threshold is reached.

  16. Fabrication Process Development for Light Deformable Mirrors

    Data.gov (United States)

    National Aeronautics and Space Administration — The project objective is to develop robust, reproductibble fabrication processes to realize functional deformable membrane mirrors (DM) for a space mission in which...

  17. The mirror mechanism: recent findings and perspectives.

    Science.gov (United States)

    Rizzolatti, Giacomo; Fogassi, Leonardo

    2014-01-01

    Mirror neurons are a specific type of visuomotor neuron that discharge both when a monkey executes a motor act and when it observes a similar motor act performed by another individual. In this article, we review first the basic properties of these neurons. We then describe visual features recently investigated which indicate that, besides encoding the goal of motor acts, mirror neurons are modulated by location in space of the observed motor acts, by the perspective from which the others' motor acts are seen, and by the value associated with the object on which others' motor acts are performed. In the last part of this article, we discuss the role of the mirror mechanism in planning actions and in understanding the intention underlying the others' motor acts. We also review some human studies suggesting that motor intention in humans may rely, as in the monkey, on the mirror mechanism.

  18. Reflections on mirror neurons and speech perception.

    Science.gov (United States)

    Lotto, Andrew J; Hickok, Gregory S; Holt, Lori L

    2009-03-01

    The discovery of mirror neurons, a class of neurons that respond when a monkey performs an action and also when the monkey observes others producing the same action, has promoted a renaissance for the Motor Theory (MT) of speech perception. This is because mirror neurons seem to accomplish the same kind of one to one mapping between perception and action that MT theorizes to be the basis of human speech communication. However, this seeming correspondence is superficial, and there are theoretical and empirical reasons to temper enthusiasm about the explanatory role mirror neurons might have for speech perception. In fact, rather than providing support for MT, mirror neurons are actually inconsistent with the central tenets of MT.

  19. Auditory–vocal mirroring in songbirds

    Science.gov (United States)

    Mooney, Richard

    2014-01-01

    Mirror neurons are theorized to serve as a neural substrate for spoken language in humans, but the existence and functions of auditory–vocal mirror neurons in the human brain remain largely matters of speculation. Songbirds resemble humans in their capacity for vocal learning and depend on their learned songs to facilitate courtship and individual recognition. Recent neurophysiological studies have detected putative auditory–vocal mirror neurons in a sensorimotor region of the songbird's brain that plays an important role in expressive and receptive aspects of vocal communication. This review discusses the auditory and motor-related properties of these cells, considers their potential role on song learning and communication in relation to classical studies of birdsong, and points to the circuit and developmental mechanisms that may give rise to auditory–vocal mirroring in the songbird's brain. PMID:24778375

  20. Fast Picometer Mirror Mount, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a 6DOF controllable mirror mount with high dynamic range and fast tip/tilt capability for space based applications. It will enable the...

  1. Additive Manufacturing of Telescope Mirrors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase 1 SBIR is to demonstrate feasibility of using selective laser melting (SLM) to produce a 3-meter symmetrical radius of curvature (ROC) isogrid mirror...

  2. High Resolution Silicon Deformable Mirrors, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal we describe a plan to build a deformable mirror suitable for space-based operation in systems for high-resolution imaging. The prototype DM will be...

  3. High Resolution Silicon Deformable Mirrors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal describes a plan to build a prototype small stroke, high precision deformable mirror suitable for space-based operation in systems for high-resolution...

  4. Nonlinear mirror mode dynamics: Simulations and modeling

    Czech Academy of Sciences Publication Activity Database

    Califano, F.; Hellinger, Petr; Kuznetsov, E.; Passot, T.; Sulem, P. L.; Trávníček, Pavel

    2008-01-01

    Roč. 113, - (2008), A08219/1-A08219/20 ISSN 0148-0227 R&D Projects: GA AV ČR IAA300420702; GA AV ČR IAA300420602 Grant - others:PECS(CZ) 98024 Institutional research plan: CEZ:AV0Z30420517 Keywords : mirror instability * nonlinear evolution * numerical simulations * magnetic holes * mirror structures * kinetic plasma instabilities Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.147, year: 2008

  5. Two-zone double phase conjugate mirror

    Science.gov (United States)

    Belić, M. R.; Vujić, D.; Sandfuchs, O.; Kaiser, F.

    2001-10-01

    An analysis of photorefractive (PR) oscillators consisting of two facing four-wave mixing regions is carried out. The threshold and operation conditions of different phase conjugate mirrors are discussed with the help of the grating action method. In particular, the threshold and the operation of the two-zone double phase conjugate mirror (DPCM) is compared with other related PR oscillators, the interconnected ring, and different connected DPCM.

  6. Authors’ response: mirror neurons: tests and testability.

    Science.gov (United States)

    Catmur, Caroline; Press, Clare; Cook, Richard; Bird, Geoffrey; Heyes, Cecilia

    2014-04-01

    Commentators have tended to focus on the conceptual framework of our article, the contrast between genetic and associative accounts of mirror neurons, and to challenge it with additional possibilities rather than empirical data. This makes the empirically focused comments especially valuable. The mirror neuron debate is replete with ideas; what it needs now are system-level theories and careful experiments – tests and testability.

  7. Action observation: Inferring intentions without mirror neurons

    DEFF Research Database (Denmark)

    Frith, Christopher; Kilner, James M

    2008-01-01

    A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand.......A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand....

  8. On horizonless temperature with an accelerating mirror

    Energy Technology Data Exchange (ETDEWEB)

    Good, Michael R.R.; Yelshibekov, Khalykbek [Department of Physics, School of Science and Technology, Nazarbayev University,53 Kabanbay Batyr Ave., Astana, 010000 Republic of (Kazakhstan); Ong, Yen Chin [Center for Astronomy and Astrophysics, Department of Physics and Astronomy,Shanghai Jiao Tong University, Shanghai, 200240 (China); Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, Stockholm, SE-106 91 (Sweden)

    2017-03-03

    A new solution of a unitary moving mirror is found to produce finite energy and emit thermal radiation despite the absence of an acceleration horizon. In the limit that the mirror approaches the speed of light, the model corresponds to a black hole formed from the collapse of a null shell. For speeds less than light, the black hole correspondence, if it exists, is that of a remnant.

  9. Fabrication of off-axis parabolic mirrors

    International Nuclear Information System (INIS)

    Bezik, M.J.; Gerth, H.L.; Sladky, R.E.; Washington, C.A.

    1978-08-01

    The report describes the fabrication process, including metal preparation, copper electroplating, single-crystal-diamond turning, optical inspection, and polishing, used to manufacture the focusing mirrors for the 10-kJ laser fusion experiment being conducted by the Los Alamos Scientific Laboratory. Fabrication of these mirrors by the techniques described resulted in diffraction-limited optics at a 10.6 μm wavelength

  10. Mirror Writing and a Dissociative Identity Disorder

    OpenAIRE

    Le, Catherine; Smith, Joyce; Cohen, Lewis

    2009-01-01

    Individuals with dissociative identity disorder (DID) have been known to show varied skills and talents as they change from one dissociative state to another. For example, case reports have described people who have changed their handedness or have spoken foreign languages during their dissociative states. During an interview with a patient with DID, a surprising talent emerged when she wrote a sentence for the Folstein Mini-Mental State Exam—mirror writing. It is not known whether her mirror...

  11. The uncanny mirror: a re-framing of mirror self-experience.

    Science.gov (United States)

    Rochat, Philippe; Zahavi, Dan

    2011-06-01

    Mirror self-experience is re-casted away from the cognitivist interpretation that has dominated discussions on the issue since the establishment of the mirror mark test. Ideas formulated by Merleau-Ponty on mirror self-experience point to the profoundly unsettling encounter with one's specular double. These ideas, together with developmental evidence are re-visited to provide a new, psychologically and phenomenologically more valid account of mirror self-experience: an experience associated with deep wariness. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. New tandem accelerator facility of Tokyo University

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Hatori, Satoshi; Nakano, Chuichiro

    1993-01-01

    An old tandem accelerator is being replaced by a new one at the University of Tokyo. The new facility consists of a vertical 5 MV Pelletron with two ion sources and dedicated beam lines for fine analytical studies. (orig.)

  13. Inverted 3J Tandem Thermophotovoltaic Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Semiconductor proposes to make an InGaAs-based three-junction (3J) tandem thermophotovoltaic (TPV) cell to utilize more of the blackbody spectrum (from a GPHS)...

  14. Ultralightweight low-temperature fused Zerodur mirror

    Science.gov (United States)

    Miller, Jennifer; Crowe, David A.; Clark, Patrick; Marker, Alexander J.

    1995-09-01

    The performance and utility of optical systems can be significantly improved by using lightweight stable mirror components. Such components have been incorporated into a mirror assembly through a process that utilizes low temperature fusion to bond low CTE faceplates onto a lightweight core structure. The core structure is fabricated using an abrasive waterjet cutting technique that enables the designer to optimize core geometry to enhance the structural performance of the blank. The faceplates are bonded to the lightweight core resulting in a stiff structural mirror. A 15.125 inch Zerodur mirror was fabricated using this unique process and subjected to a test program to measure the optical stability of the mirror in support of either space-based applications. Strength testing was performed to verify the integrity of the fused joints and determine appropriate design allowable stress. A thermal test program was designed to assess performance at various temperature extremes and a mechanical load test was run to verify the capability of the blank to withstand operational loads without degrading the optical surface. The surface figure of the part was measured before, during, and after a 200 degree F temperature cycle with no change in figure quality. In addition, the mirror was subjected to a 10 g load for ten minutes with no change in the figure quality.

  15. Large deviations for tandem queueing systems

    Directory of Open Access Journals (Sweden)

    Roland L. Dobrushin

    1994-01-01

    Full Text Available The crude asymptotics of the large delay probability in a tandem queueing system is considered. The main result states that one of the two channels in the tandem system defines the crude asymptotics. The constant that determines the crude asymptotics is given. The results obtained are based on the large deviation principle for random processes with independent increments on an infinite interval recently established by the authors.

  16. Vortex shedding from tandem cylinders

    Science.gov (United States)

    Alam, Md. Mahbub; Elhimer, Mehdi; Wang, Longjun; Jacono, David Lo; Wong, C. W.

    2018-03-01

    An experimental investigation is conducted on the flow around tandem cylinders for ranges of diameter ratio d/ D = 0.25-1.0, spacing ratio L/ d = 5.5-20, and Reynolds number Re = 0.8 × 104-2.42 × 104, where d and D are the diameters of the upstream and downstream cylinders, respectively, L is the distance from the upstream cylinder center to the forward stagnation point of the downstream one. The focus is given on examining the effects of d/ D, L/ d and Re on Strouhal number St, flow structures and fluid forces measured using hotwire, particle image velocimetry (PIV) and load cell measurement techniques, respectively. Changes in d/ D and L/ d in the ranges examined lead to five flow regimes, namely lock-in, intermittent lock-in, no lock-in, subharmonic lock-in and shear-layer reattachment regimes. Time-mean drag coefficient ( C D) and fluctuating drag and lift coefficients ({C^'D} and {C^'L}) are more sensitive to L/ d than d/ D. The scenario is opposite for St where d/ D is more prominent than L/ d to change the St. The detailed facet of the dependence on d/ D and L/ d of C D, {C^'D}, {C^'L} and St is discussed based on shear-layer velocity, approaching velocity, vortex formation length, and wake width.

  17. Potential of the Galaxy from the Besançon galaxy model including non-axisymmetric components: Preliminary results

    Science.gov (United States)

    Fernández-Trincado, J. G.; Robin, A. C.; Bienaymé, O.; Reylé, C.; Valenzuela, O.; Pichardo, B.

    2014-07-01

    In this contributed poster we present a preliminary attempt to compute a non-axisymmetric potential together with previous axisymmetric potential of the Besançon galaxy model. The contribution by non-axisymmetric components are modeled by the superposition of inhomogeneous ellipsoids to approximate the triaxial bar and superposition of homogeneous oblate spheroids for a stellar halo, possibly triaxial. Finally, we have computed the potential and force field for these non-axisymmetric components in order to constraint the total mass of the Milky Way. We present preliminary results for the rotation curve and the contribution of the bar to it. This approach will allow future studies of dynamical constraints from comparisons of kinematical simulations with upcoming surveys such as RAVE, BRAVA, APOGEE, and GAIA in the near future. More details, are presented in https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/Poster_JG.Fern%e1ndez.pdf.

  18. On solution of Maxwell's equations in axisymmetric domains with edges. Part II: Numerical aspects

    International Nuclear Information System (INIS)

    Nkemzi, Boniface

    2003-10-01

    In this paper we consider the Fourier-finite-element method for treating the Maxwell's equations in three-dimensional axisymmetric domains with reentrant edges. By means of partial Fourier analysis, the 3D BVP is decomposed into an infinite sequence of 2D variational equations in the plane meridian domain of the axisymmetric domain, a finite number of which is considered and treated using nodal H 1 -conforming finite elements. For domains with reentrant edges, the singular field method is employed to compensate the singular behavior of the solutions. Emphases are given to estimates of the Fourier-finite-element approximation error and convergence analysis in the H 1 -norm under different regularity assumptions. (author)

  19. Excitation of nonaxisymmetric perturbations by the axisymmetric explosive magnetorotational instability in Keplerian discs

    Science.gov (United States)

    Shtemler, Yu.; Mond, M.; Liverts, E.

    2018-02-01

    The excitation of nonaxisymmetric quasi-resonant triads by clustering around a dominant axisymmetric explosively unstable magnetorotational instability (MRI) in Keplerian discs is investigated. Clustering, namely, the mutual interactions of a large number of quasi-resonant triads that are connected by a single dominant explosively unstable axisymmetric triad, is invoked in order to provide a viable mechanism for the stabilization of the explosive nature of the latter. The results, however, are of wider scope as the proposed clustering scenario also provides a strong mechanism for the excitation of high-amplitude nonaxisymmetric perturbations. The latter play a major role in the nonlinear evolution of the MRI on the route to fully developed turbulence.

  20. Application of Quasi-Newton methods to the analysis of axisymmetric pressure vessels

    International Nuclear Information System (INIS)

    Parisi, D.A.C.

    1987-01-01

    This work studies the application of Quasi-Newton techniques to material nonlinear analysis of axisymmetrical pressure vessels by the finite element method. In the formulation the material bahavior is described by an isotropic elastoplastic model with strain hardening. The continum is discretized through triangular finite elements of axisymmetrical solids with linear interpolation of the displacement field. The incremental governing equations are derived by the virtual work. The solution of the system of simultaneous nonlinear equations is solved iteratively by the Quasi-Newton method employing the BFGS update. The numerical performance of the proposed method is compared with the Newton-Raphson method and some of its variants through some selected examples. (author) [pt

  1. On Perturbation Solutions for Axisymmetric Bending Boundary Values of a Deep Thin Spherical Shell

    Directory of Open Access Journals (Sweden)

    Rong Xiao

    2014-01-01

    Full Text Available On the basis of the general theory of elastic thin shells and the Kirchhoff-Love hypothesis, a fundamental equation for a thin shell under the moment theory is established. In this study, the author derives Reissner’s equation with a transverse shear force Q1 and the displacement component w. These basic unknown quantities are derived considering the axisymmetry of the deep, thin spherical shell and manage to constitute a boundary value question of axisymmetric bending of the deep thin spherical shell under boundary conditions. The asymptotic solution is obtained by the composite expansion method. At the end of this paper, to prove the correctness and accuracy of the derivation, an example is given to compare the numerical solution by ANSYS and the perturbation solution. Meanwhile, the effects of material and geometric parameters on the nonlinear response of axisymmetric deep thin spherical shell under uniform external pressure are also analyzed in this paper.

  2. Effect of Axisymmetric Aft Wall Angle Cavity in Supersonic Flow Field

    Science.gov (United States)

    Jeyakumar, S.; Assis, Shan M.; Jayaraman, K.

    2018-03-01

    Cavity plays a significant role in scramjet combustors to enhance mixing and flame holding of supersonic streams. In this study, the characteristics of axisymmetric cavity with varying aft wall angles in a non-reacting supersonic flow field are experimentally investigated. The experiments are conducted in a blow-down type supersonic flow facility. The facility consists of a supersonic nozzle followed by a circular cross sectional duct. The axisymmetric cavity is incorporated inside the duct. Cavity aft wall is inclined with two consecutive angles. The performance of the aft wall cavities are compared with rectangular cavity. Decreasing aft wall angle reduces the cavity drag due to the stable flow field which is vital for flame holding in supersonic combustor. Uniform mixing and gradual decrease in stagnation pressure loss can be achieved by decreasing the cavity aft wall angle.

  3. Optimal cloning of arbitrary mirror-symmetric distributions on the Bloch sphere: a proposal for practical photonic realization

    International Nuclear Information System (INIS)

    Bartkiewicz, Karol; Miranowicz, Adam

    2012-01-01

    We study state-dependent quantum cloning that can outperform universal cloning (UC). This is possible by using some a priori information on a given quantum state to be cloned. Specifically, we propose a generalization and optical implementation of quantum optimal mirror phase-covariant cloning, which refers to optimal cloning of sets of qubits of known modulus of the expectation value of Pauli's Z operator. Our results can be applied to cloning of an arbitrary mirror-symmetric distribution of qubits on the Bloch sphere including in special cases UC and phase-covariant cloning. We show that the cloning is optimal by adapting our former optimality proof for axisymmetric cloning (Bartkiewicz and Miranowicz 2010 Phys. Rev. A 82 042330). Moreover, we propose an optical realization of the optimal mirror phase-covariant 1→2 cloning of a qubit, for which the mean probability of successful cloning varies from 1/6 to 1/3 depending on prior information on the set of qubits to be cloned. The qubits are represented by polarization states of photons generated by the type-I spontaneous parametric down-conversion. The scheme is based on the interference of two photons on an unbalanced polarization-dependent beam splitter with different splitting ratios for vertical and horizontal polarization components and the additional application of feedforward by means of Pockels cells. The experimental feasibility of the proposed setup is carefully studied including various kinds of imperfections and losses. Moreover, we briefly describe two possible cryptographic applications of the optimal mirror phase-covariant cloning corresponding to state discrimination (or estimation) and secure quantum teleportation.

  4. Numerical modelling of a thin deformable mirror for laser beam control

    CSIR Research Space (South Africa)

    Long, CS

    2010-01-01

    Full Text Available to account for non-axisymmetric voltage distributions, and therefore non-axisymmetric displacements. The Rayleigh-Ritz model, which uses the Zernike polynomials directly to describe the displacements, produced a small model (stiffness matrix dimension equal...

  5. Utilization of axisymmetrical models in the description of the fluctuating temperature field and in the calculation of turbulent thermal diffusivity

    International Nuclear Information System (INIS)

    Cintra Filho, J. de S.

    1981-01-01

    The fluctuating temperature field structure is studied for the case of turbulent circular pipe flow. Experimentally determined integral length scales are used in modeling this structure in terms of axisymmetric forms. It is found that the appropriate angle of axisymmetry is larger than the one for modeling the large scale velocity structure. The axisymmetric model is then used to examine the validity and the prediction capability of the Tyldesley and Silver's non-spherical eddy diffusivity theory. (Author) [pt

  6. Axisymmetric solid-of-revolution finite elements with rotational degrees of freedom

    CSIR Research Space (South Africa)

    Long, CS

    2009-01-01

    Full Text Available of the axis of radial symmetry. Weissman and Taylor [23] introduced two elements based on the Hellinger- Reissner functional. Their elements employ the popular Pian and Sumihara interpolation, modified to obtain correct rank for the axisymmetric case... option however. Essentially, we adopt the procedure suggested by Jog and Annabat- tula [25], who proposed the selection of interpolation functions such that zero- energy modes (associated with reduced integrations schemes) are captured. In their paper...

  7. NOVA: a nonvariational code for solving MHD stability of axisymmetric toroidal plasmas

    International Nuclear Information System (INIS)

    Cheng, C.Z.; Chance, M.S.

    1986-04-01

    A nonvariational approach for determining the ideal MHD stability of axisymmetric toroidal confinement systems is presented. The code (NOVA) employs cubic B-spline finite elements and Fourier expansion in a general flux coordinate (psi, theta, zeta) system. Better accuracy and faster convergence were obtained in comparison with the variational PEST and ERATO codes. The nonvariational approach can be extended to problems having non-Hermitian eigenmode equations where variational energy principles cannot be obtained

  8. Numerical analysis of laser ablation using the axisymmetric two-temperature model

    Science.gov (United States)

    Dziatkiewicz, Jolanta; Majchrzak, Ewa

    2018-01-01

    Laser ablation of the axisymmetric micro-domain is analyzed. To describe the thermal processes occurring in the micro-domain the two-temperature hyperbolic model supplemented by the boundary and initial conditions is used. This model takes into account the phase changes of material (solid-liquid and liquid-vapour) and the ablation process. At the stage of numerical computations the finite difference method with staggered grid is used. In the final part the results of computations are shown.

  9. AxisSPH:devising and validating an axisymmetric smoothed particle hydrodynamics code

    OpenAIRE

    Relaño Castillo, Antonio

    2012-01-01

    A two-dimensional axisymmetric implementation of the smoothed particle hydrodynamics (SPH) technique, called for short AxisSPH, has been described in this thesis, along with a number of basic tests and realistic applications. The main goal of this work was to fill a gap on a topic which has been scarcely addressed in the published literature concerning SPH. Although the application of AxisSPH to the simulation of real problems is restricted to those systems which display the appropriate ...

  10. Effects of shape and stroke parameters on the propulsion performance of an axisymmetric swimmer

    International Nuclear Information System (INIS)

    Peng Jifeng; Alben, Silas

    2012-01-01

    In nature, there exists a special group of aquatic animals which have an axisymmetric body and whose primary swimming mechanism is to use periodic body contractions to generate vortex rings in the surrounding fluid. Using jellyfish medusae as an example, this study develops a mathematical model of body kinematics of an axisymmetric swimmer and uses a computational approach to investigate the induced vortex wakes. Wake characteristics are identified for swimmers using jet propulsion and rowing, two mechanisms identified in previous studies of medusan propulsion. The parameter space of body kinematics is explored through four quantities: a measure of body shape, stroke amplitude, the ratio between body contraction duration and extension duration, and the pulsing frequency. The effects of these parameters on thrust, input power requirement and circulation production are quantified. Two metrics, cruising speed and energy cost of locomotion, are used to evaluate the propulsion performance. The study finds that a more prolate-shaped swimmer with larger stroke amplitudes is able to swim faster, but its cost of locomotion is also higher. In contrast, a more oblate-shaped swimmer with smaller stroke amplitudes uses less energy for its locomotion, but swims more slowly. Compared with symmetric strokes with equal durations of contraction and extension, faster bell contractions increase the swimming speed whereas faster bell extensions decrease it, but both require a larger energy input. This study shows that besides the well-studied correlations between medusan body shape and locomotion, stroke variables also affect the propulsion performance. It provides a framework for comparing the propulsion performance of axisymmetric swimmers based on their body kinematics when it is difficult to measure and analyze their wakes empirically. The knowledge from this study is also useful for the design of robotic swimmers that use axisymmetric body contractions for propulsion. (paper)

  11. Solving the Axisymmetric Inverse Heat Conduction Problem by a Wavelet Dual Least Squares Method

    Directory of Open Access Journals (Sweden)

    Fu Chu-Li

    2009-01-01

    Full Text Available We consider an axisymmetric inverse heat conduction problem of determining the surface temperature from a fixed location inside a cylinder. This problem is ill-posed; the solution (if it exists does not depend continuously on the data. A special project method—dual least squares method generated by the family of Shannon wavelet is applied to formulate regularized solution. Meanwhile, an order optimal error estimate between the approximate solution and exact solution is proved.

  12. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.; Kessel, C.; Monticello, D.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    2001-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  13. MHD Stability Calculations of High-Beta Quasi-Axisymmetric Stellarators

    International Nuclear Information System (INIS)

    Kessel, C.; Fu, G.Y.; Ku, L.P.; Redi, M.H.; Pomphrey, N.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size

  14. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.H.; Kessel, C.; Monticello, D.A.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  15. The nonlinear behaviour of axisymmetric hydromagnetic waves in a partially ionized plasma

    International Nuclear Information System (INIS)

    Sawley, M.

    1977-10-01

    Finite amplitude effects in the propagation of axisymmetric hydromagnetic waves in a cylindrical, magnetized plasma are considered. The influence of the Hall term and the presence of neutral atoms on the resulting second order fields is examined. The combined effect of these two factors is to produce a substantial secord order azimuthal field, in addition to the axial field predicted by earlier work which neglected these factors. In some circumstances this azimuthal field is much larger than the axial field. (Author)

  16. Unravelling the optical responses of nanoplasmonic mirror-on-mirror metamaterials

    NARCIS (Netherlands)

    Sikdar, D.; Hasan, Shakeeb Bin; Urbakh, M.; Edel, J.B.; Kornyshev, A.A.

    2016-01-01

    Mirror-on-mirror platforms based on arrays of metallic nanoparticles, arranged top-down or self-assembled on a thin metallic film, have interesting optical properties. Interaction of localized surface-plasmons in nanoparticles with propagating surface-plasmons in the film underpins the exotic

  17. Mirror, mirror on the wall, how does my brain recognize my image at all?

    Directory of Open Access Journals (Sweden)

    David L Butler

    Full Text Available For decades researchers have used mirrors to study self-recognition. However, attempts to identify neural processes underlying this ability have used photographs instead. Here we used event related potentials (ERPs to compare self-face recognition in photographs versus mirrors and found distinct neural signatures. Measures of visual self-recognition are therefore not independent of the medium employed.

  18. Comparison of in vitro flows past a mechanical heart valve in anatomical and axisymmetric aorta models

    Science.gov (United States)

    Haya, Laura; Tavoularis, Stavros

    2017-06-01

    Flow characteristics past a bileaflet mechanical heart valve were measured under physiological flow conditions in a straight tube with an axisymmetric expansion, similar to vessels used in previous studies, and in an anatomical model of the aorta. We found that anatomical features, including the three-lobed sinus and the aorta's curvature affected significantly the flow characteristics. The turbulent and viscous stresses were presented and discussed as indicators for potential blood damage and thrombosis. Both types of stresses, averaged over the two axial measurement planes, were significantly lower in the anatomical model than in the axisymmetric one. This difference was attributed to the lower height-to-width ratio and more gradual contraction of the anatomical aortic sinus. The curvature of the aorta caused asymmetries in the velocity and stress distributions during forward flow. Secondary flows resulting from the aorta's curvature are thought to have redistributed the fluid stresses transversely, resulting in a more homogeneous stress distribution in the anatomical aortic root than in the axisymmetric root. The results of this study demonstrate the importance of modelling accurately the aortic geometry in experimental and computational studies of prosthetic devices. Moreover, our findings suggest that grafts used for aortic root replacement should approximate as closely as possible the shape of the natural sinuses.

  19. Mirror theory applied to toroidal systems

    International Nuclear Information System (INIS)

    Cohen, R.H.

    1987-01-01

    Central features of a mirror plasma are strong departures from Maxwellian distribution functions, ambipolar potentials and densities which vary along a field line, end losses, and the mirror field itself. To examine these features, mirror theorists have developed analytical and numerical techniques to solve the Fokker-Planck equation, evaluate the potentials consistent with the resulting distribution functions, and assess the microstability of these distributions. Various combinations of mirror-plasma features are present and important in toroidal plasmas as well, particularly in the edge region and in plasmas with strong rf heating. In this paper we survey problems in toroidal plasmas where mirror theory and computational techniques are applicable, and discuss in more detail three specific examples: calculation of the toroidal generalization of the Spitzer-Haerm distribution function (from which trapped-particle effects on current drive can be calculated), evaluation of the nonuniform potential and density set up by pulsed electron-cyclotron heating, and calculation of steady-state distribution functions in the presence of strong rf heating and collisions. 37 refs

  20. Thermal performance of the ATST secondary mirror

    Science.gov (United States)

    Cho, Myung K.; DeVries, Joe; Hansen, Eric

    2007-12-01

    The Advanced Technology Solar Telescope (ATST) has a 4.24m off-axis primary mirror designed to deliver diffractionlimited images of the sun. Its baseline secondary mirror (M2) design uses a 0.65m diameter Silicon Carbide mirror mounted kinematically by a bi-pod flexure mechanism at three equally spaced locations. Unlike other common telescopes, the ATST M2 is to be exposed to a significant solar heat loading. A thermal management system (TMS) will be developed to accommodate the solar loading and minimize "mirror seeing effect" by controlling the temperature difference between the M2 optical surface and the ambient air at the site. Thermo-elastic analyses for steady state thermal behaviors of the ATST secondary mirror was performed using finite element analysis by I-DEAS TM and PCRINGE TM for the optical analysis. We examined extensive heat transfer simulation cases and their results were discussed. The goal of this study is to establish thermal models by I-DEAS for an adequate thermal environment. These thermal models will be useful for estimating segment thermal responses. Current study assumes a few sample time dependent thermal loadings to synthesize the operational environment.