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Sample records for 2xiib mirror machine

  1. Alpha Channeling in Mirror Machines

    SciTech Connect

    Fisch N.J.

    2005-10-19

    Because of their engineering simplicity, high-β, and steady-state operation, mirror machines and related open-trap machines such as gas dynamic traps, are an attractive concept for achieving controlled nuclear fusion. In these open-trap machines, the confinement occurs by means of magnetic mirroring, without the magnetic field lines closing upon themselves within the region of particle confinement. Unfortunately, these concepts have not achieved to date very spectacular laboratory results, and their reactor prospects are dimmed by the prospect of a low Q-factor, the ratio of fusion power produced to auxiliary power. Nonetheless, because of its engineering promise, over the years numerous improvements have been proposed to enhance the reactor prospects of mirror fusion, such as tandem designs, end-plugging, and electric potential barriers.

  2. Evolution of the mirror machine

    SciTech Connect

    Damm, C. C.

    1983-08-18

    The history of the magnetic-mirror approach to a fusion reactor is primarily the history of our understanding and control of several crucial physics issues, coupled with progress in the technology of heating and confining a reacting plasma. The basic requirement of an MHD-stable plasma equilibrium was achieved following the early introduction of minimum-B multipolar magnetic fields. In refined form, the same magnetic-well principle carries over to our present experiments and to reactor designs. The higher frequency microinstabilities, arising from the non-Maxwellian particle distributions inherent in mirror machines, have gradually come under control as theoretical prescriptions for distribution functions have been applied in the experiments. Even with stability, the classical plasma leakage through the mirrors posed a serious question for reactor viability until the principle of electrostatic axial stoppering was applied in the tandem mirror configuration. Experiments to test this principle successfully demonstrated the substantial improvement in confinement predicted. Concurrent with advances in mirror plasma physics, development of both high-power neutral beam injectors and high-speed vacuum pumping techniques has played a crucial role in ongoing experiments. Together with superconducting magnets, cryogenic pumping, and high-power radiofrequency heating, these technologies have evolved to a level that extrapolates readily to meet the requirements of a tandem mirror fusion reactor.

  3. Applying alpha-channeling to mirror machines

    SciTech Connect

    Zhmoginov, A. I.; Fisch, N. J.

    2012-05-15

    The {alpha}-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic {alpha} particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Originally proposed for tokamaks, this technique has also been shown to benefit open-ended fusion devices. Here, the fundamental theory and practical aspects of {alpha} channeling in mirror machines are reviewed, including the influence of magnetic field inhomogeneity and the effect of a finite wave region on the {alpha}-channeling mechanism. For practical implementation of the {alpha}-channeling effect in mirror geometry, suitable contained weakly damped modes are identified. In addition, the parameter space of candidate waves for implementing the {alpha}-channeling effect can be significantly extended through the introduction of a suitable minority ion species that has the catalytic effect of moderating the transfer of power from the {alpha}-channeling wave to the fuel ions.

  4. Plasma-wall interactions in tandem mirror machines

    SciTech Connect

    Allen, S.L.

    1984-11-01

    A description is presented of the plasma-surface interactions in thermal-barrier tandem-mirror machines. The thermal-barrier mode of axial confinement is an integral part of a tandem mirror, and it dictates the required plasma conditions, particularly at the surface of the plasma. For this reason, a qualitative discussion of the thermal barrier is presented first in Section 2. A brief description of the experimental configuration used in tandem mirrors to create the thermal barrier is then examined in detail in Section 3; the TMX-U and MFTF-B machines are used as specific examples. In Section 4, the relevant plasma-surface interaction issues are addressed, and experimental results from currently operating tandom mirror machines are included. Section 5 is both a summary and a discussion of future work concerned with plasma-surface interactions in tandem mirrors.

  5. New technique of machining high precision mirror surface press roller

    NASA Astrophysics Data System (ADS)

    Hongsen, Deng

    1991-03-01

    High precision mirror surface press roller machining technique of corrosion and grinding proof is one of the key techniques that the production enterprises as well as the machining and manufacturing of the following industries sought to resolve for a long time: plastics, papermaking, rubber, film, and chip production. In Oct. 1984, a new comprehensive machining technique of metal brush coating, grinding with abrasive belt, as well as buffing was used to conduct nearly 20 experiments. In Jan. 1985, a pair of middle convex high precision mirror surface press rollers was successfully machined. The technical process is described.

  6. An Automatic Washing Machine to Remove Aluminum From Astronomical Mirrors

    NASA Astrophysics Data System (ADS)

    Zitelli, Valentina

    Cleaning of large astronomical mirrors, before aluminization, required in the past a large amount of manual operations on the surface. With very large mirrors, 8 meter or more, manual operations become time consuming, expensive and often dangerous, both for mirror surface and operators. A fully automated procedure is thus mandatory when handling large mirrors. To this aim we experimented on a small scale (60 cm) an automatic procedure, free from any manual contact with the mirror, capable of removing old aluminum and leaving a clean, wet surface ready for a successful new aluminization. First we manually treated small borosilicate mirrors, obtained from the LBT primary mirror glass batch, with different sequences of chemicals, commonly used to this purpose. These small mirrors were checked with a Wyko interferometer before and after treating, to trace change in roughness of the surface. Quality and stability of the new aluminum deposition after cleaning was also checked. The washing machine prototype is composed by a water proof box on rigid PVC with a moving arm, a pump and a series of tanks containing the used chemicals. All the adopted components can be used with acids and other corrosive fluids. The machine is designed to hold the mirror in vertical position. An arm with 10 cm spaced nozzles moves up and down in front of the mirror spraying the adopted chemicals in a defined sequence. A pump forces the liquid through the circuit. After the washing, the mirror is left, protected from the dust in the washing machine, for about 2 hours to drip the water, then is moved into the vacuum pump to check the final result of aluminizing the cleaned surface. A homogeneous layer of aluminum follows only after a careful cleaning, otherwise a fast oxidize process, or a inhomogeneous aluminum coating appear. Scaling times, fluxes and costs from this experiment to large size mirrors leads to realistic, affordable figures.

  7. Waves for Alpha-Channeling in Mirror Machines

    SciTech Connect

    A. I. Zhmoginov and N. J. Fisch

    2009-07-08

    Alpha-channeling can, in principle, be implemented in mirror machines via exciting weaklydamped modes in the ion cyclotron frequency range with perpendicular wavelengths smaller than the alpha particle gyroradius. Assuming quasi-longitudinal or quasi-transverse wave propagation, we search systematically for suitable modes in mirror plasmas. Considering two device designs, a proof-of-principle facility and a fusion rector prototype, we in fact identify candidate modes suitable for alpha-channeling.

  8. Diamond Machining of an Off-Axis Biconic Aspherical Mirror

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Preuss, Werner; Sohn, Alex; MacKenty, John

    2009-01-01

    Two diamond-machining methods have been developed as part of an effort to design and fabricate an off-axis, biconic ellipsoidal, concave aluminum mirror for an infrared spectrometer at the Kitt Peak National Observatory. Beyond this initial application, the methods can be expected to enable satisfaction of requirements for future instrument mirrors having increasingly complex (including asymmetrical), precise shapes that, heretofore, could not readily be fabricated by diamond machining or, in some cases, could not be fabricated at all. In the initial application, the mirror is prescribed, in terms of Cartesian coordinates x and y, by aperture dimensions of 94 by 76 mm, placements of -2 mm off axis in x and 227 mm off axis in y, an x radius of curvature of 377 mm, a y radius of curvature of 407 mm, an x conic constant of 0.078, and a y conic constant of 0.127. The aspect ratio of the mirror blank is about 6. One common, "diamond machining" process uses single-point diamond turning (SPDT). However, it is impossible to generate the required off-axis, biconic ellipsoidal shape by conventional SPDT because (1) rotational symmetry is an essential element of conventional SPDT and (2) the present off-axis biconic mirror shape lacks rotational symmetry. Following conventional practice, it would be necessary to make this mirror from a glass blank by computer-controlled polishing, which costs more than diamond machining and yields a mirror that is more difficult to mount to a metal bench. One of the two present diamond machining methods involves the use of an SPDT machine equipped with a fast tool servo (FTS). The SPDT machine is programmed to follow the rotationally symmetric asphere that best fits the desired off-axis, biconic ellipsoidal surface. The FTS is actuated in synchronism with the rotation of the SPDT machine to generate the difference between the desired surface and the best-fit rotationally symmetric asphere. In order to minimize the required stroke of the FTS

  9. Feedback effect on flute dynamics in a mirror machine

    NASA Astrophysics Data System (ADS)

    Be'Ery, Ilan; Seemann, Omri

    2015-11-01

    Active feedback techniques may stabilize the flute instability in mirror traps and make them viable candidates for fusion machines. A fast feedback with optical sensors and electrical actuators was implemented in a table-top mirror machine and used to study several aspects of feedback stabilization. For a cold, dense plasma the feedback reduces dramatically the flute amplitude of the first two mode. For higher temperature plasma, a significant increase of plasma density due to feedback stabilization is also demonstrated. The effect of changing feedback gain and phase has some interesting feature such as asymmetry with respect to positive and negative phase shifts and non-monotonic dependence of flute amplitude on feedback gain. These effects are explained using simplified analytic model of the flute and feedback.

  10. Simulation of Alpha-Channeling in Mirror Machines

    SciTech Connect

    A.I. Zhmoginov, N.J. Fisch

    2008-03-17

    Applying α-channeling techniques to mirror machines can significantly increase their effective reactivity, thus making open configurations more advantageous for practical fusion. A large fraction of α particle energy can be extracted using rf waves. Effects employed to cool α particles can also in principle be used to heat the fusion ions; the possibility to design a configuration of rf waves which could be used to perform both tasks is demonstrated.

  11. Feasibility Studies of Alpha-Channeling in Mirror Machines

    SciTech Connect

    A. I. Zhmoginov and N. J. Fisch

    2010-03-19

    The linear magnetic trap is an attractive concept both for fusion reactors and for other plasma applications due to its relative engineering simplicity and high-beta operation. Applying the α- channeling technique to linear traps, such as mirror machines, can benefit this concept by efficiently redirecting α particle energy to fuel ion heating or by otherwise sustaining plasma confinement, thus increasing the effective fusion reactivity. To identify waves suitable for α-channeling a rough optimization of the energy extraction rate with respect to the wave parameters is performed. After the optimal regime is identified, a systematic search for modes with similar parameters in mirror plasmas is performed, assuming quasi-longitudinal or quasi-transverse wave propagation. Several modes suitable for α particle energy extraction are identified for both reactor designs and for proof- of-principle experiments.

  12. Feedback effect on flute dynamics in a mirror machine

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.

    2015-08-01

    The effect of active feedback on flute instability is experimentally studied in a table-top mirror machine. Changing the plasma conditions from mirror-loss dominated to flute-loss dominated, it is demonstrated that while the feedback has no effect on plasma density in the first case, it increases the plasma density by up to 50% in the second case. Measurements of the dependence of instability amplitude on feedback gain show that large gain stimulates high frequency perturbations. The period of these perturbations corresponds to the inherent delay of immersed electrode feedback. Variation of the spatial phase between the input and output of the phase reveals a large asymmetry between positive and negative phase shifts. A simplified model is introduced to explain how a negative phase shift causes positive feedback between the external feedback and the centrifugally driven rotation.

  13. Density increase due to active feedback in mirror machine

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2014-10-01

    Mirror machines are one of the schemes for future fusion systems. Its main drawbacks are the flute instability and being open ended which results in plasma losses. A feedback system is used to stabilize the flute instability in a table top mirror machine with a continuous plasma source and RF heating. Under certain source density and temperature conditions, although the plasma was stabilized, plasma density increase was not measured. After decreasing the source density and increasing the temperature, Plasma density increase was achieved. It is theorized that these results are due to transition of the plasma main loss mechanism from collision dominated to instability dominated. In the former, the main density loss is through diffusion and In the latter, it is through flute instability which drives the plasma to the edge of the vacuum chamber. Future research directions are discussed for a planned machine which should achieve higher temperatures and better diagnostic capabilities. The research will focus on magnetic actuators and passive RF stabilization.

  14. Flute growth rate of plasma jet in mirror machine

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.; Goldstein, G.; Fisher, A.; Ron, A.

    2014-02-01

    The evolution of flute instability in a cold, high-density hydrogen plasma jet, injected into a mirror machine, is studied. The experiment was designed to minimize the interaction of the plasma with the walls, thus bringing it close to the ideal magnetic Rayleigh-Taylor instability conditions. The modal growth rate was measured in various settings to demonstrate the effects of the finite Larmor radius, Bohm diffusion, conductive limiter, biased limiter and neutral background gas. In this paper we will demonstrate that lowering the magnetic field increases stability, as does the insertion of a conducting ring. However, if the ring is biased, the stability is reduced due to inhomogeneous coupling between the plasma and the limiter. It was also found that heavy background gas dramatically reduces the flute instability growth rate.

  15. Study on the Stressed Mirror Polishing with a Continuous Polishing Machine for Large Aperture Off-axis Aspheric Mirrors

    NASA Astrophysics Data System (ADS)

    Li, Xin-nan; Zhang, Hai-ying; Cui, Xiang-qun; Jiang, Zi-bo; Zheng, Yi; Liu, Xing-tao; Ni, Hou-kun

    2012-10-01

    A special stressed annular polishing technique is proposed to mill the off-axis aspheric sub-mirrors of a large segmented mirror with an annular polishing machine. Based on the basic principle of stressed annular polishing technique, a set of special stressing mechanisms are designed to convert milling the aspheric surfaces of sub-mirrors with different off-axis distances into milling the spherical surfaces with identical radii of curvature, so that they can be pol- ished simultaneously on a continuous polishing machine. It took about contin- uous 40 hours to polish a scaled-down mirror of the planning Chinese Future Giant Telescope (CFGT) using this technique. This mirror has the 330 mm di- ameter, 3.6 m off-axis distance, and the 21.6 m radius of curvature, and its max- imum asphericity is 16 micron. The experiment shows that this method has a high effciency, suits batch manufacturing, especially the batch manufacturing of aspheric sub-mirrors of the segmented primary mirror of an extremely large aperture telescope.

  16. Generation of high-order optical vortices using directly machined spiral phase mirrors.

    PubMed

    Campbell, Geoff; Hage, Boris; Buchler, Ben; Lam, Ping Koy

    2012-03-01

    We report on the generation of high-order optical vortices by spiral phase mirrors (SPMs). The mirrors are produced by direct machining with a diamond tool and are shown to produce high-quality optical vortices with topological charges ranging from 1 to upwards of 100 at a wavelength of 532 nm. The direct machining technique is flexible and offers the promise of high-precision, large-diameter SPMs that are compatible with high optical powers. PMID:22410888

  17. Ultraprecision 5-Axis Control Machining of Fly-Eye Mirror in EUV Lithography

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yoshinori; Takeuchi, Yoshimi; Kawai, Tomohiko; Sawada, Kiyoshi; Takino, Hideo; Nomura, Kazushi

    The study deals with the manufacture of fly-eye mirrors for EUVL by means of ultraprecision 5-axis control milling. The mirrors consist of many small spherical mirror elements with many steps among them. In the present study, two new methods for manufacturing the mirrors using a single-crystal diamond tool are proposed. One method uses a sphere type tool with a circular arc cutting edge. Though the method is theoretically efficient, it is found that it is not practical due to the difficulty of manufacturing the tool accurately. The other one uses a cylinder type tool with a right-angled cutting edge. The tool enables the manufacturing of spherical surfaces with any radius and supports practical use because the efficiency of this method is independent of tool form accuracy. The fly-eye mirror was machined by the latter method to have an array of four spherical mirror elements with the required steps and without any burrs.

  18. Mirror device aligns machine surface perpendicular to sight lines

    NASA Technical Reports Server (NTRS)

    Kissler, H. R.

    1964-01-01

    A sight alignment device is used to align two machines so that an axis of the first machine is parallel to a flat surface on the second. This sighting device depends on the reflection of a light beam from the surface to be aligned.

  19. Machine Protection System for the Stepper Motor Actuated SyLMAND Mirrors

    NASA Astrophysics Data System (ADS)

    Subramanian, V. R.; Achenbach, S.; Dolton, W.; Wells, G.; Hallin, E.; Klymyshyn, D. M.; Augustin, M.

    2010-06-01

    SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices at the Canadian Light Source, consists of a dedicated X-ray lithography beamline on a bend magnet port, and process support laboratories in a clean room environment. The beamline includes a double mirror system with flat, chromium-coated silicon mirrors operated at varying grazing angles of incidence (4 mrad to 45 mrad) for spectral adjustment by high energy cut-off. Each mirror can be independently moved by two stepper motors to precisely control the pitch and vertical position. We present in this paper the machine protection system implemented in the double mirror system to allow for safe operation of the two mirrors and to avoid consequences of potential stepper motor malfunction.

  20. Machine Protection System for the Stepper Motor Actuated SyLMAND Mirrors

    SciTech Connect

    Subramanian, V. R.; Dolton, W.; Wells, G.; Hallin, E.; Achenbach, S.; Klymyshyn, D. M.; Augustin, M.

    2010-06-23

    SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices at the Canadian Light Source, consists of a dedicated X-ray lithography beamline on a bend magnet port, and process support laboratories in a clean room environment. The beamline includes a double mirror system with flat, chromium-coated silicon mirrors operated at varying grazing angles of incidence (4 mrad to 45 mrad) for spectral adjustment by high energy cut-off. Each mirror can be independently moved by two stepper motors to precisely control the pitch and vertical position. We present in this paper the machine protection system implemented in the double mirror system to allow for safe operation of the two mirrors and to avoid consequences of potential stepper motor malfunction.

  1. Fabrication of mitigation pits for improving laser damage resistance in dielectric mirrors by femtosecond laser machining

    SciTech Connect

    Wolfe, Justin E.; Qiu, S. Roger; Stolz, Christopher J.

    2011-03-20

    Femtosecond laser machining is used to create mitigation pits to stabilize nanosecond laser-induced damage in multilayer dielectric mirror coatings on BK7 substrates. In this paper, we characterize features and the artifacts associated with mitigation pits and further investigate the impact of pulse energy and pulse duration on pit quality and damage resistance. Our results show that these mitigation features can double the fluence-handling capability of large-aperture optical multilayer mirror coatings and further demonstrate that femtosecond laser macromachining is a promising means for fabricating mitigation geometry in multilayer coatings to increase mirror performance under high-power laser irradiation.

  2. Generalized energy principle for flute perturbations in axisymmetric mirror machines

    SciTech Connect

    Lansky, I.M.; Ryutov, D.D.

    1993-01-20

    Axial symmetry is a very desirable property of the mirror devices both for fusion and neutron source applications. The main obstacle to be circumvented in the development of such systems, is the flute instability of axisymmetric mirrors. In recent years there appeared a number of proposals, devoted to the stabilization of the flute perturbations in the framework of axisymmetric magnetic configurations, which are based on the combining of the MHD unstable central cell with various types of end-cell stabilizers. In the present paper we concentrate ourselves just on this scheme, including long solenoid with a uniform field, conjugated with the end stabilizing anchor, intended to provide MHD stability of the system as a whole. The attractive feature of such a configuration is that it allows to exploit finite larmor radius (FLR) effects for the stabilization of the flute perturbations. As is well known, FLR effects, being strong, stabilize all flute modes, except the one with azimuthal number m = 1, corresponding to the ``rigid`` displacement of the plasma column (the ``global`` mode). Consequently, in the conditions when FLR effects dominate, the anchor has to stabilize the ``global` mode only. Bearing in mind a favorable influence of FLR effects we, however, don`t restrict our paper by discussion of only ``global`` mode stability and consider a general case of an arbitrary azimuthal mode.

  3. Demonstration of Minimally Machined Honeycomb Silicon Carbide Mirrors

    NASA Technical Reports Server (NTRS)

    Goodman, William

    2012-01-01

    Honeycomb silicon carbide composite mirrors are made from a carbon fiber preform that is molded into a honeycomb shape using a rigid mold. The carbon fiber honeycomb is densified by using polymer infiltration pyrolysis, or through a reaction with liquid silicon. A chemical vapor deposit, or chemical vapor composite (CVC), process is used to deposit a polishable silicon or silicon carbide cladding on the honeycomb structure. Alternatively, the cladding may be replaced by a freestanding, replicated CVC SiC facesheet that is bonded to the honeycomb. The resulting carbon fiber-reinforced silicon carbide honeycomb structure is a ceramic matrix composite material with high stiffness and mechanical strength, high thermal conductivity, and low CTE (coefficient of thermal expansion). This innovation enables rapid, inexpensive manufacturing. The web thickness of the new material is less than 1 millimeter, and core geometries tailored. These parameters are based on precursor carbon-carbon honeycomb material made and patented by Ultracor. It is estimated at the time of this reporting that the HoneySiC(Trademark) will have a net production cost on the order of $38,000 per square meter. This includes an Ultracor raw material cost of about $97,000 per square meter, and a Trex silicon carbide deposition cost of $27,000 per square meter. Even at double this price, HoneySiC would beat NASA's goal of $100,000 per square meter. Cost savings are estimated to be 40 to 100 times that of current mirror technologies. The organic, rich prepreg material has a density of 56 kilograms per cubic meter. A charred carbon-carbon panel (volatile organics burnt off) has a density of 270 kilograms per cubic meter. Therefore, it is estimated that a HoneySiC panel would have a density of no more than 900 kilograms per cubic meter, which is about half that of beryllium and about onethird the density of bulk silicon carbide. It is also estimated that larger mirrors could be produced in a matter of weeks

  4. Hardware Photos: Image Showing JWST Engineering Demonstration Mirror, Mounted Ready for Machining at AXYS and Image Showing HIP Can Containing Light Mirrors 1 and 2 Ready for Mirror Fabrication

    NASA Technical Reports Server (NTRS)

    OKeefe, Sean

    2004-01-01

    The images in this viewgraph presentation have the following captions: 1) EDU mirror after being sawed in half; 2) EDU Delivered to Axsys; 3) Be EDU Blank Received and Machining Started; 4) Loaded HIP can for flight PM segments 1 and 2; 5) Flight Blanks 1 and 2 Loaded into HIP Can at Brush-Wellman; 6) EDU in Machining at Axsys.

  5. Developing on-machine 3D profile measurement for deterministic fabrication of aspheric mirrors.

    PubMed

    Dong, Zhichao; Cheng, Haobo; Ye, Xu; Tam, Hon-Yuen

    2014-08-01

    Three-dimensional profile measurement is perceived as an indispensable process for deterministic fabrication of aspheric mirrors. In this work, we develop on-machine 3D profile measurement on a subaperture polishing machine, namely, JR-1800. The influences of mechanical errors, misalignments, output stability, temperature variation, and natural vibration are investigated in detail by calibration, mechanical alignment, and finite-element analysis. Two quantitative methods are presented for aligning the turntable, length gauge, and workpiece into together. An error compensation model is also developed for further eliminating misalignments. For feasibility validation, two prototypical workpieces are measured by JR-1800 and an interferometer. The results indicate that JR-1800 has an RMS repeatability of ~λ/30 (λ=632.8  nm). The data provided by the two systems are highly coincident. Direct subtractions of the results from the two systems indicate that the RMS deviations for both segments are less than 0.07 μm. PMID:25090332

  6. Determination Of Plasma Parameters In The PUPR Mirror and Cusp Plasma Machine Via Electrostatic Probe Methods

    SciTech Connect

    Meyer, Ryan M.; Rivera, Miguel A.; Colmenares, Franklyn; Leal, David; Rivera, Ramon; Leal-Quiros, Edbertho; Gonzales, Angel

    2006-12-04

    Electrostatic probes are constructed for the PUPR Mirror and Cusp Plasma Machine and preliminary measurements of the plasma parameters are obtained. The machine is cylindrical in shape with two copper coils wound around the machine to provide the necessary mirror or cusp field configuration. The plasma is heated using the electron cyclotron heating method at a frequency of 2.45 GHz. I-V characteristics are obtained using single, double, and emissive Langmuir probes in Argon plasma at approximately 1*10-4 Torr and with approximate field strength of {approx} 0.1T at the point cusp. The single and double Langmuir probes consist of 3.5 mm radius stainless steel disks. Characteristics are obtained for the single and double Langmuir probes using a source meter and programming a voltage sweep while recording the current from the digital readout. The emissive probe is constructed by using a tungsten filament and characteristics are obtained in a manner similar to that described for the single and double Langmuir probes. An emission current is superposed on top of the sweeping signal using a DC power source. An electron temperature of approximately 7.5eV is observed in the plasma at a density of {approx}4.0*1014m-3 using the single Langmuir probe. In addition, with the distribution function obtained from the single probe, the plasma potential is observed to be approximately 25-30V. The measurement of 25-30V for the plasma potential is supported by measurements obtained from the emissive probe.

  7. Determination Of Plasma Parameters In The PUPR Mirror and Cusp Plasma Machine Via Electrostatic Probe Methods

    NASA Astrophysics Data System (ADS)

    Meyer, Ryan M.; Rivera, Miguel A.; Colmenares, Franklyn; Leal, David; Rivera, Ramon; Gonzales, Angel; Leal-Quiros, Edbertho

    2006-12-01

    Electrostatic probes are constructed for the PUPR Mirror and Cusp Plasma Machine and preliminary measurements of the plasma parameters are obtained. The machine is cylindrical in shape with two copper coils wound around the machine to provide the necessary mirror or cusp field configuration. The plasma is heated using the electron cyclotron heating method at a frequency of 2.45 GHz. I-V characteristics are obtained using single, double, and emissive Langmuir probes in Argon plasma at approximately 1*10-4 Torr and with approximate field strength of ˜ 0.1T at the point cusp. The single and double Langmuir probes consist of 3.5 mm radius stainless steel disks. Characteristics are obtained for the single and double Langmuir probes using a source meter and programming a voltage sweep while recording the current from the digital readout. The emissive probe is constructed by using a tungsten filament and characteristics are obtained in a manner similar to that described for the single and double Langmuir probes. An emission current is superposed on top of the sweeping signal using a DC power source. An electron temperature of approximately 7.5eV is observed in the plasma at a density of ˜4.0*1014m-3 using the single Langmuir probe. In addition, with the distribution function obtained from the single probe, the plasma potential is observed to be approximately 25-30V. The measurement of 25-30V for the plasma potential is supported by measurements obtained from the emissive probe.

  8. Parameters optimization in a fission-fusion system with a mirror machine based neutron source

    NASA Astrophysics Data System (ADS)

    Yurov, D. V.; Anikeev, A. V.; Bagryansky, P. A.; Brednikhin, S. A.; Frolov, S. A.; Lezhnin, S. I.; Prikhodko, V. V.

    2012-06-01

    Long-lived fission products utilization is a problem of high importance for the modern nuclear reactor technology. BINP jointly with NSI RAS develops a conceptual design of a hybrid sub-critical minor actinides burner with a neutron source based on the gas dynamic mirror machine (GDT) to resolve the stated task. A number of modelling tools was created to calculate the main parameters of the device. First of the codes, GENESYS, is a zero-dimensional code, designed for plasma dynamics numerical investigation in a GDT-based neutron source. The code contains a Monte-Carlo module for the determination of linear neutron emission intensity along the machine axis. Fuel blanket characteristics calculation was implemented by means of a static Monte-Carlo code NMC. Subcritical core, which has been previously analyzed by OECD-NEA, was used as a template for the fuel blanket of the modelled device. This article represents the codes used and recent results of the described system parameters optimization. Particularly, optimum emission zone length of the source and core multiplicity dependence on buffer zone thickness were defined.

  9. Design, Fabrication, Optical Testing, and Performance of Diamond Machined Aspheric Mirrors for Ground-Based Near-IR Astronomy

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Mink, Ronald; Chambers, V. John; Connelly, Joseph A.; Mentzell, J. Eric; Tveekrem, June L.; Howard, Joseph M.; Preuss, Werner; Schroeder, Mechthild; Sohn, Alex; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    Challenges in fabrication and testing have historically limited the choice of surfaces available for the design of reflective optical instruments. Spherical and conic mirrors are common, but, for future science instruments, more degrees of freedom are necessary to meet challenging performance and packaging requirements. These instruments will be composed of unusual aspheres located far off-axis with large spherical departure, and some designs will require asymmetric surface profiles. In particular, single-surface astigmatism correction in spectrographs necessitates a toroidal surface, which lacks an axis of rotational symmetry. We describe the design, fabrication, optical testing, and performance of three rotationally symmetric, off-axis, aspheric mirrors and one toroidal, off-axis, biconic camera mirror on aluminum substrates for the Infrared Multi-Object Spectrograph (IRMOS) instrument. IRMOS is a facility instrument for the Kitt Peak National Observatory's Mayall Telescope (3.8 m) and an engineering prototype for a possible design of the Next Generation Space Telescope/Multi-Object Spectrograph. The symmetric mirrors range in aperture from 94x86 mm to 286x269 mm and in f-number from 0.9 to 2.4. They are various off-axis, convex and concave, prolate and oblate ellipsoids. The concave biconic mirror has a 94x76 mm aperture, Rx=377 mm, kx=0.0778, Ry=407 mm, and ky=0.1265 and is decentered. by -2 mm in x and 227 mm in y. The mirrors have an aspect ratio of approximately 4:1. The surface error fabrication tolerances are less than 63.3 nm RMS figure error and less than 10 nm RMS microroughness. The mirrors are attached to the instrument bench via a semi-kinematic, integral flexure mount. We describe mirror design, diamond machining, the results of figure testing using computer-generated holograms, and imaging and scattered light modeling and performance.

  10. Design Study of an X-ray Crystal Spectrometer for the HANBIT Mirror Machine

    NASA Astrophysics Data System (ADS)

    Lee, S. G.; Hwang, S. M.; Bitter, M. L.

    1997-11-01

    X-ray crystal spectroscopy is expected to play a major role for the diagnostics of the reactor-like plasmas produced in future large tokamaks, such as KSTAR and ITER. However, it is also desirable to extend the observable spectral range to longer wavelengths (7-15 dotA), which is of interest for the diagnostics of plasmas with much lower electron densities (10^11-10^12 cm-3) and electron temperatures (100 - 200 eV) in other magnetic-confinement experiments, such as the HANBIT mirror machine. The construction of crystal spectrometers for this wavelength range and these plasma conditions is challenging because of the low X-ray emissivity and the fact that the low-energy X-rays are strongly attenuated by even very thin foils or windows. New types of detectors other than the presently used multi-wire proportional counters are therefore needed to obtain a high detection efficiency. In this paper, we present a design study for a vacuum spectrometer with a CCD array detector and detailed estimates of the instrument performance for the observation of spectra from O, Ne and Al ions.

  11. Development of a numerically controlled elastic emission machining system for fabricating mandrels of ellipsoidal focusing mirrors used in soft x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Takei, Yoshinori; Kume, Takehiro; Motoyama, Hiroto; Hiraguri, Kentaro; Hashizume, Hirokazu; Mimura, Hidekazu

    2013-09-01

    Ellipsoidal mirrors are one of the most promising types of X-ray mirror, because the mirror can focus X-rays to nanometer size with a large aperture and no chromatic aberration. However, so far ideal ellipsoidal mirrors cannot be realized by any manufacturing methods. One of the reasons is there is no fabrication method to process their inside surface with a diameter of several millimeters with nanometer-level accuracy. We propose and develop a manufacturing process of the ellipsoidal mirror. First, a master which has the reversed shape is prepared using grinding, polishing and Elastic Emission Machining (EEM). EEM can finish the surface shape to within 2nm (RMS). Then, the ellipsoidal mirror is produced by replicating the surface using an electroforming deposition method. By conducting the process without any stress at room temperature, replicating the surface roughness and shape with nanometer order accuracy is possible. In this paper, we report the current status of manufacturing of the ellipsoidal mirror.

  12. Surface-figuring CVD-SiC mirrors with a five-axis-control ultraprecision grinding machine

    NASA Astrophysics Data System (ADS)

    Namba, Yoshiharu; Suzuki, Hiroshi

    1997-11-01

    A large 5-axis control ultraprecision grinding machine has been developed for making synchrotron-radiation mirrors with high accuracy. The positional and angular resolutions of the machine are 10 nm and 0.0002 degree, respectively. The dimensions of the machine are 3.3 m by 2.7 m by 4.4 m in height. The machine can generate non-axisymmetric aspheric surfaces on CVD-SiC material by a disc-type metal-bonded diamond wheel. An electric micrometer has been set near a grinding head for measuring the form error of ground surface in conformity with the machine movement due to the cutter location data. A series of the measured form errors corrects the former cutter location data automatically and the next grinding operation will be performed by the new cutter location data. A CVD-SiC material of 510 mm by 110 mm was ground into a toroidal surface of 750 nm in shape accuracy by the fifth grinding operation with the fourth correction of cutter location data. More than 99% of toroidal surface area have a form accuracy less than 500 nm. 3.3 nm rms surface roughness was obtained by the ultraprecision grinding using a SD4000N150M metal-bonded diamond wheel.

  13. Optical Testing of Diamond Machined, Aspheric Mirrors for Groundbased, Near-IR Astronomy

    NASA Technical Reports Server (NTRS)

    Chambers, V. John; Mink, Ronald G.; Ohl, Raymond G.; Connelly, Joseph A.; Mentzell, J. Eric; Arnold, Steven M.; Greenhouse, Matthew A.; Winsor, Robert S.; MacKenty, John W.

    2002-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a facility-class instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8-2.5 micron) spectrometer and operates at approximately 80 K. The 6061-T651 aluminum bench and mirrors constitute an athermal design. The instrument produces simultaneous spectra at low- to mid-resolving power (R=lambda/delta lambda= 300-3000) of approximately 100 objects in its 2.8 x 2.0 arcmin field. We describe ambient and cryogenic optical testing of the IRMOS mirrors across a broad range in spatial frequency (figure error, mid-frequency error, and microroughness). The mirrors include three rotationally symmetric, off-axis conic sections, one off-axis biconic, and several flat fold mirrors. The symmetric mirrors include convex and concave prolate and oblate ellipsoids. They range in aperture from 94x86 mm to 286x269 mm and in f-number from 0.9 to 2.4. The biconic mirror is concave and has a 94x76 mm aperture, R(sub x)=377 mm, k(sub x)=0.0778, R(sub y)=407 mm, and k(sub y)=0.1265 and is decentered by -2 mm in X and 227 mm in Y. All of the mirrors have an aspect ratio of approximately 6:1. The surface error fabrication tolerances are less than 10 nm RMS microroughness, 'best effort' for mid-frequency error, and less than 63.3 nm RMS figure error. Ambient temperature (approximately 293 K) testing is performed for each of the three surface error regimes, and figure testing is also performed at approximately 80 K. Operation of the ADE Phaseshift MicroXAM white light interferometer (micro-roughness) and the Bauer Model 200 profilometer (mid-frequency error) is described. Both the sag and conic values of the aspheric mirrors make these tests challenging. Figure testing is performed using a Zygo GPI interferometer, custom computer generated holograms (CGH), and optomechanical alignment fiducials. Cryogenic CGH null testing is discussed in detail. We discuss complications such as the change in

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

    SciTech Connect

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

    1986-08-01

    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 (T-italicapprox. >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/sup -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-italic = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented.

  15. Controllable Mirror Devices

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A deformable Mirror Device (DMD) is a type of spatial light modulator in which mirrors fabricated monolithically on a silicon chip are deformed, or tilted, under electronic control to change the direction of light that falls upon the mirror. NASA and Texas Instruments (TI) have worked to develop this technology, which has subsequently been commercialized by TI. Initial application is the DMD 2000 Travel Information Printer for high speed, high volume printing of airline tickets and boarding passes. Other possible applications range from real-time object tracking to advanced industrial machine vision systems.

  16. Virtual Mirrors

    ERIC Educational Resources Information Center

    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…

  17. ECRH in tandem mirror machines

    SciTech Connect

    Stallard, B.W.

    1983-05-27

    The thermal barrier concept and the use of ECRH to generate the several electron populations required to establish confinement are discussed. Important physics issues related to the microwave heating are discussed. Fokker-Planck calculations which model the heating processes are presented, followed by recent experimental data on hot electron heating.

  18. Mirror mount

    DOEpatents

    Kuklo, Thomas C.; Bender, Donald A.

    1994-01-01

    A unique lens or mirror mount having adjustable constraints at two key locations to allow for "X" and "Y" tilts of the mirror only. The device uses two pair of flexures of a type such that the pivots of the mirror gimble are rigidly fixed in all planes allowing the device to have zero stacking tolerance and zero wear over time.

  19. Einstein's Mirror

    ERIC Educational Resources Information Center

    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…

  20. Chiral mirrors

    SciTech Connect

    Plum, Eric; Zheludev, Nikolay I.

    2015-06-01

    Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.

  1. Micromachined mirrors

    NASA Astrophysics Data System (ADS)

    Conant, Robert Alan

    This dissertation discusses the fundamental limits of scanning mirror design, focusing on the limitations due to the interaction between mechanical properties (mirror flatness and dynamic deformation), and optical properties (beam divergence and optical resolution). The performance criteria for both resonant-scanning mirrors and steady-state, beam-positioning mirrors are related to the mirror geometries, desired optical resolution, material properties, and mechanical resonant frequencies. The optical resolution of the scanning mirror is linearly dependent on the mirror length, so longer mirrors should provide higher-resolution scanners. However, when undergoing an angular acceleration mirrors exhibit dynamic deformation, which is shown to be proportional to the fifth power of the length. Two different implementations of MEMS scanning mirrors are presented: polysilicon surface-micromachined mirrors and a new design we call the Staggered Torsional Electrostatic Combdrive (STEC) micromirror. The surface-micromachined mirrors are shown to be capable of reliable operation, but they have significant performance limitations caused by the limited thickness obtainable with the LPCVD-polysilicon structures. Calculations show that surface-micromachined mirrors of thickness 1.5 mum and diameter 550 mum are only capable of scanning +/-10 degrees at 251 Hz while retaining diffraction-limited optical performance. The STEC micromirrors, designed to overcome the limitations of the surface-micromachined mirrors, are capable of much higher-speed scanning (up to 61 kHz) without performance-limiting dynamic deformation of the mirror surface. The STEC micromirror fabrication process is extended to create Tensile Optical Surface (TOS) micromirrors---mirrors with thick silicon rib support structures and thin membranes that provide the reflective surface. An application of scanning mirrors is presented: a raster-scanning video display. This demonstration uses two surface

  2. Castable Amorphous Metal Mirrors and Mirror Assemblies

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    A revolutionary way to produce a mirror and mirror assembly is to cast the entire part at once from a metal alloy that combines all of the desired features into the final part: optical smoothness, curvature, flexures, tabs, isogrids, low CTE, and toughness. In this work, it has been demonstrated that castable mirrors are possible using bulk metallic glasses (BMGs, also called amorphous metals) and BMG matrix composites (BMGMCs). These novel alloys have all of the desired mechanical and thermal properties to fabricate an entire mirror assembly without machining, bonding, brazing, welding, or epoxy. BMGs are multi-component metal alloys that have been cooled in such a manner as to avoid crystallization leading to an amorphous (non-crystalline) microstructure. This lack of crystal structure and the fact that these alloys are glasses, leads to a wide assortment of mechanical and thermal properties that are unlike those observed in crystalline metals. Among these are high yield strength, carbide-like hardness, low melting temperatures (making them castable like aluminum), a thermoplastic processing region (for improving smoothness), low stiffness, high strength-to-weight ratios, relatively low CTE, density similar to titanium alloys, high elasticity and ultra-smooth cast parts (as low as 0.2-nm surface roughness has been demonstrated in cast BMGs). BMGMCs are composite alloys that consist of a BMG matrix with crystalline dendrites embedded throughout. BMGMCs are used to overcome the typically brittle failure observed in monolithic BMGs by adding a soft phase that arrests the formation of cracks in the BMG matrix. In some cases, BMGMCs offer superior castability, toughness, and fatigue resistance, if not as good a surface finish as BMGs. This work has demonstrated that BMGs and BMGMCs can be cast into prototype mirrors and mirror assemblies without difficulty.

  3. Mirror mount

    DOEpatents

    Kuklo, T.C.; Bender, D.A.

    1994-10-04

    A unique lens or mirror mount having adjustable constraints at two key locations to allow for ''X'' and ''Y'' tilts of the mirror only is disclosed. The device uses two pair of flexures of a type such that the pivots of the mirror gimble are rigidly fixed in all planes allowing the device to have zero stacking tolerance and zero wear over time. 4 figs.

  4. Helically linked mirror arrangement

    SciTech Connect

    Ranjan, P.

    1986-08-01

    A scheme is described for helical linking of mirror sections, which endeavors to combine the better features of toroidal and mirror devices by eliminating the longitudinal loss of mirror machines, having moderately high average ..beta.. and steady state operation. This scheme is aimed at a device, with closed magnetic surfaces having rotational transform for equilibrium, one or more axisymmetric straight sections for reduced radial loss, a simple geometrical axis for the links and an overall positive magnetic well depth for stability. We start by describing several other attempts at linking of mirror sections, made both in the past and the present. Then a description of our helically linked mirror scheme is given. This example has three identical straight sections connected by three sections having helical geometric axes. A theoretical analysis of the magnetic field and single-particle orbits in them leads to the conclusion that most of the passing particles would be confined in the device and they would have orbits independent of pitch angle under certain conditions. Numerical results are presented, which agree well with the theoretical results as far as passing particle orbits are concerned.

  5. Magic Mirrors

    ERIC Educational Resources Information Center

    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…

  6. Slumped mirrors

    NASA Astrophysics Data System (ADS)

    Pteancu, Mircea; Dragan, Dorin; Dragan, Olivier; Miron, Andrei; Stanescu, Octavian

    2008-02-01

    The authors discusse the construction of slumped mirrors, their fabrication and testing (polishing and lapping). An important topic of the discussion is thermal fabrication of mirrors by using of matrixes. One of the authors of the entry is combining astronomy and aquariums construction.

  7. Einstein's Mirror

    NASA Astrophysics Data System (ADS)

    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.

  8. Fueling of tandem mirror reactors

    SciTech Connect

    Gorker, G.E.; Logan, B.G.

    1985-01-01

    This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed for the Tandem Mirror Reactor Systems Code (TMRSC) to select the pellet injector/accelerator combination which most nearly satisfies the fueling requirements for a given machine design.

  9. Mirror, Mirror on the Wall...?

    ERIC Educational Resources Information Center

    Pflaster, Gail

    1979-01-01

    The study determined the value of using a mirror for speech teaching by recording manner, place, voicing, and blend errors produced by 27 hearing-impaired children (5-13 years old) while imitating consonant-vowel syllables under three conditions (audition alone, audition plus direct vision, and audition plus vision using a mirror). (Author)

  10. Mirror mount

    DOEpatents

    Humpal, H.H.

    1987-11-10

    A mirror mount is provided that allows free pitch, yaw and roll motion of the mirror while keeping the location of a point on the surface of the mirror fixed in the rest frame of reference of the mount. Yaw movement is provided by two yaw cylinders that are bearing mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell that is air bearing mounted to move between a clamp and an upper pedestal bearing. The centers of curvature of the spherical surfaces of the shell lie upon the point. Pitch motion and roll motion are separately and independently imparted to mirror by a pair of pitch paddles and a pair of roll paddles that are independently and separately moved by control rods driven by motors. 5 figs.

  11. Mirror mount

    DOEpatents

    Humpal, H.H.

    1986-03-21

    A mirror mount is provided that allows free pitch, yaw and roll motion of the mirror while keeping the location of a point on the surface of the mirror fixed in the rest frame of reference of the mount. Yaw movement is provided by two yaw cylinders that are bearing mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell that is air bearing mounted to move between a clamp and an upper pedestal bearing. The centers of curvature of the spherical surfaces of the shell lie upon the point. Pitch motion and roll motion are separately and independently imparted to mirror by a pair of pitch paddles and a pair of roll paddles that are independently and separately moved by control rods driven by motors.

  12. Mirror mount

    DOEpatents

    Humpal, Harold H.

    1987-01-01

    A mirror mount (10) is provided that allows free pitch, yaw and roll motion of the mirror (28) while keeping the location of a point (56) on the surface of the mirror (28) fixed in the rest frame of reference of the mount (10). Yaw movement is provided by two yaw cylinders (30,32) that are bearing (52) mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell (42) that is air bearing (72,74) mounted to move between a clamp (60) and an upper pedestal bearing (44). The centers of curvature of the spherical surfaces of the shell (42) lie upon the point (56). Pitch motion and roll motion are separately and independently imparted to mirror (28) by a pair of pitch paddles (34) and a pair of roll paddles (36) that are independently and separately moved by control rods (76,80) driven by motors (78,82).

  13. Mirror Technology

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Under a NASA contract, MI-CVD developed a process for producing bulk silicon carbide by means of a chemical vapor deposition process. The technology allows growth of a high purity material with superior mechanical/thermal properties and high polishability - ideal for mirror applications. The company employed the technology to develop three research mirrors for NASA Langley and is now marketing it as CVD SILICON CARBIDE. Its advantages include light weight, thermal stability and high reflectivity. The material has nuclear research facility applications and is of interest to industrial users of high power lasers.

  14. Conicoid Mirrors

    ERIC Educational Resources Information Center

    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.)

  15. Mirror Support

    NASA Technical Reports Server (NTRS)

    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.

  16. Mirror, Mirror, on the Wall.

    ERIC Educational Resources Information Center

    Flowers, Jim; Rose, M. Annette

    1998-01-01

    Students use tables of anthropometric data, their own measurements, underlying principles of physics, and math to solve a problem. The problem is to determine the height of a wall mirror, and where to mount it, so that 90% of the clientele can view their entire length without stretching or bending. (Author)

  17. Mirror monochromator

    SciTech Connect

    Mankos, Marian; Shadman, Khashayar

    2014-12-02

    In this SBIR project, Electron Optica, Inc. (EOI) is developing a mirror electron monochromator (MirrorChrom) attachment to new and retrofitted electron microscopes (EMs) for improving the energy resolution of the EM from the characteristic range of 0.2-0.5 eV to the range of 10-50 meV. This improvement will enhance the characterization of materials by imaging and spectroscopy. In particular, the monochromator will refine the energy spectra characterizing materials, as obtained from transmission EMs [TEMs] fitted with electron spectrometers, and it will increase the spatial resolution of the images of materials taken with scanning EMs (SEMs) operated at low voltages. EOI’s MirrorChrom technology utilizes a magnetic prism to simultaneously deflect the electron beam off the axis of the microscope column by 90° and disperse the electrons in proportional to their energies into a module with an electron mirror and a knife-edge. The knife-edge cuts off the tails of the energy distribution to reduce the energy spread of the electrons that are reflected, and subsequently deflected, back into the microscope column. The knife-edge is less prone to contamination, and thereby charging, than the conventional slits used in existing monochromators, which improves the reliability and stability of the module. The overall design of the MirrorChrom exploits the symmetry inherent in reversing the electron trajectory in order to maintain the beam brightness – a parameter that impacts how well the electron beam can be focused downstream onto a sample. During phase I, EOI drafted a set of candidate monochromator architectures and evaluated the trade-offs between energy resolution and beam current to achieve the optimum design for three particular applications with market potential: increasing the spatial resolution of low voltage SEMs, increasing the energy resolution of low voltage TEMs (beam energy of 5-20 keV), and increasing the energy resolution of conventional TEMs (beam

  18. Mirror systems

    SciTech Connect

    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. (LEW)

  19. Chinese "Magic" Mirrors.

    ERIC Educational Resources Information Center

    Swinson, Derek B.

    1992-01-01

    Chinese "magic" mirrors are made from bronze with the front side a mirror and the reverse side a molded image. When light is reflected from the mirror,the image on the reverse side appears. Discusses reflections of conventional mirrors, possible explanations for the magic mirror phenomenon, and applications of the phenomenon to semiconductor…

  20. Lessons learned in recent beryllium mirror fabrication

    NASA Astrophysics Data System (ADS)

    Wells, J. A.; Lombard, C. M.; Sloan, G. B.; Moore, W. W.; Martin, C. E.

    1991-09-01

    The lessons learned in recent fabrication of beryllium mirrors could have a significant impact on how beryllium optics of the future are produced. This paper provides an overview of the latest techniques for beryllium optics fabrication and a comparison of the results achieved. Specific technical ureas discussed include: new beryllium powders, results of consolidation, beryllium material property improvements, modified machining procedures, thermal stabilization, single point turning, burnishing techniques, replica faceplates, support structure bonding, mirror superpolishing, and new optical testing techniques.

  1. Cryostable lightweight frit bonded silicon mirror

    NASA Astrophysics Data System (ADS)

    Anthony, F.; McCarter, D.; Tangedahl, M.; Content, D.

    The excellent polishability, low density and relatively high stiffness of silicon make it an attractive candidate for optical applications that require superior performance. Assembly of silicon details by means of glass frit bonding permits significant light weighting thus enhancing the benefit of silicon mirrors. To demonstrate the performance potential, a small lightweight glass frit bonded silicon mirror was fabricated and tested for cryoability. The test mirror was 12.5cm in diameter with a 60cm spherical radius and a maximum thickness, at the perimeter, of 2.5cm. A machined silicon core was used to stiffen the two face sheets of the silicon sandwich. These three elements were assembled, by glass frit bonding, to form the substrate that was polished. The experimental evaluation in a liquid nitrogen cryostat, demonstrated cryostability performance significantly better than required by the mirror specification. Key WordsCryostable, Lightweight, Silicon, Frit Bond, Spherical, Mirror

  2. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  3. Ideal ballooning modes in axisymmetric mirror machines

    SciTech Connect

    Baldwin, D.E.; McNamara, B.; Willmann, P.

    1980-12-15

    A simple code is described that finds marginally stable (..omega../sup 2/ = 0) ballooning-type MHD modes, localized about a field line in an axisymmetric, open-ended, plasma confinement device. The equations are based on a lower bound for the perturbed energy delta W, derived by W. Newcomb from the ideal MHD energy principle, and are cast in the form of a Ricatti equation for the first derivative of the eigenfunction, with the open boundary conditions that this derivative vanish at the plasma boundary down each field line. The input to the code is the two-dimensional shape of a field line, the field strength B(s), and parameters to define pressure profiles throughout the system. The objective is to find the highest plasma pressures for which the given line is MHD-stable.

  4. SXI prototype mirror mount

    NASA Astrophysics Data System (ADS)

    1995-04-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  5. SXI prototype mirror mount

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  6. Integral Flexure Mounts for Metal Mirrors for Cryogenic Use

    NASA Technical Reports Server (NTRS)

    Zewari, S. Wahid; Hylan, Jason E.; Irish, Sandra M.; Ohl, Raymond G.; Conkey, Shelly B.

    2006-01-01

    Semi-kinematic, six-degree-of-freedom flexure mounts have been incorporated as integral parts of metal mirrors designed to be used under cryogenic conditions as parts of an astronomical instrument. The design of the mirrors and their integral flexure mounts can also be adapted to other instruments and other operating temperatures. In comparison with prior kinematic cryogenic mirror mounts, the present mounts are more compact and can be fabricated easily using Ram-EDM (electrical discharge machining) process

  7. Floating mirror mount

    SciTech Connect

    Koop, D.E.

    1989-01-03

    This patent describes a floating mirror mount for a mirror of a laser is described consisting of: a mirror having a front surface and a back surface, a keeper encircling the mirror and having a peripheral flange engaging the front surface of the mirror when the mirror is not installed in a laser, a retainer positioned rearwardly of the back surface of the mirror and connected to the keeper and having a spring seating surface, spring means engageable with the spring seating surface of the retainer for exerting a resilient biasing force on the mirror, and fastening means for connecting the retainer to the mirror positioning structure of the laser on installation of the mirror mount in the laser.

  8. Titanium Alloy Strong Back for IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Byron, Glenn P.; Kai-Wang, Chan

    2011-01-01

    A titanium-alloy mirror-holding fixture called a strong back allows the temporary and permanent bonding of a 50 degree D263 glass x-ray mirror (IXO here stands for International X-ray Observatory). The strong back is used to hold and position a mirror segment so that mounting tabs may be bonded to the mirror with ultra-low distortion of the optical surface. Ti-15%Mo alloy was the material of choice for the strong back and tabs because the coefficient of thermal expansion closely matches that of the D263 glass and the material is relatively easy to machine. This invention has the ability to transfer bonded mounting points from a temporary location on the strong back to a permanent location on the strong back with minimal distortion. Secondly, it converts a single mirror segment into a rigid body with an acceptable amount of distortion of the mirror, and then maneuvers that rigid body into optical alignment such that the mirror segment can be bonded into a housing simulator or mirror module. Key problems are that the mirrors are 0.4-mm thick and have a very low coefficient of thermal expansion (CTE). Because the mirrors are so thin, they are very flexible and are easily distorted. When permanently bonding the mirror, the goal is to achieve a less than 1-micron distortion. Temperature deviations in the lab, which have been measured to be around 1 C, have caused significant distortions in the mirror segment.

  9. Dimensional Instability In Electroplated Copper Mirrors

    NASA Astrophysics Data System (ADS)

    Cutler, R. L.; Hogan, B. M.

    1983-11-01

    The Antares high energy gas laser system uses electroplated copper mirrors to reflect the laser beam through the amplifiers and focus it on the target. These mirrors are either polished or single point diamond machined to meet rigid optical specifications. They are inspected within 24 hours after final machining using a laser interferometer. A routine reinspection of these mirrors after arrival at Los Alamos revealed that some had severe distortions far greater than allowed by the optical specifications. The worst examples exhibited a roughened surface, visible to the eye, similar to an "orange-peel" effect. Metallographic analysis of some of the mirrors showed a highly stressed layer within the electrodeposited copper. This layer had a fibrous or needle-like structure and had a micro-hardness of 170 to 180 DPH. Large, stress-free grains with a micro-hardness of 50 to 55 DPH were mixed in with the fibrous layer in some instances. It soon became evident that the hard, fibrous structure was in varying stages of recrystallization, and the recrystallization was taking place at room temperature. Further investigation revealed that the fibrous layer was the result of excessive levels of organic brightening agent in the electrolyte during the electroplating process. Enough stress was stored in the deposit due to the addition agent to provide an unstable microstructure, which subsequently recrystallized over a period of three to six months. In order to salvage the mirrors, a thermal treatment was developed to force recrystallization. Heating the mirrors to 140 for 90 minutes provides a stable microstructure which machines well. Although some of the grains are large, they have no apparent effect on machineability or reflectivity.

  10. Cryostable lightweight frit-bonded silicon mirror

    NASA Astrophysics Data System (ADS)

    Anthony, Frank M.; McCarter, Douglas R.; Tangedahl, Matt; Content, David A.

    2002-11-01

    The excellent polishability, low density and relatively high stiffness of silicon make it an attractive candidate for optical applications that require superior performance. Assembly of silicon details by means of glass frit bonding permits significant weight reduction thus enhancing the benefit of silicon mirrors. To demonstrate the performance potential, a small lightweight glass frit bonded silicon mirror was fabricated and tested for cryostability. The test mirror was 12.5cm in diameter with a 60cm spherical radius and a maximum thickness, at the perimeter, of 2.5cm. A machined silicon core was used to stiffen the two face sheets of the silicon sandwich. These three elements were assembled, by glass frit bonding, to form the substrate that was polished. The experimental evaluation, in a liquid nitrogen cryostat, demonstrated cryostability performance significantly better than required by the mirror specification.

  11. Kinematic high bandwidth mirror mount

    DOEpatents

    Kuklo, T.C.

    1995-03-21

    An adjustable mirror mount system for a mirror is disclosed comprising a mirror support having a planar surface thereon, a mirror frame containing a mirror and having a planar surface behind the mirror facing the planar surface of the mirror support and parallel to the reflecting surface of the mirror and mounted pivotally to the mirror support at a point central to the frame, a first adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along one axis lying in the plane of the planar surface of the mirror frame; and a second adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along a second axis lying in the plane of the planar surface of the mirror frame and perpendicular to the first axis. 7 figures.

  12. Kinematic high bandwidth mirror mount

    DOEpatents

    Kuklo, Thomas C.

    1995-01-01

    An adjustable mirror mount system for a mirror is disclosed comprising a mirror support having a planar surface thereon, a mirror frame containing a mirror and having a planar surface behind the mirror facing the planar surface of the mirror support and parallel to the reflecting surface of the mirror and mounted pivotally to the mirror support at a point central to the frame, a first adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along one axis lying in the plane of the planar surface of the mirror frame; and a second adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along a second axis lying in the plane of the planar surface of the mirror frame and perpendicular to the first axis.

  13. Cost-effective lightweight mirrors for aerospace and defense

    NASA Astrophysics Data System (ADS)

    Woodard, Kenneth S.; Comstock, Lovell E.; Wamboldt, Leonard; Roy, Brian P.

    2015-05-01

    The demand for high performance, lightweight mirrors was historically driven by aerospace and defense (A&D) but now we are also seeing similar requirements for commercial applications. These applications range from aerospace-like platforms such as small unmanned aircraft for agricultural, mineral and pollutant aerial mapping to an eye tracking gimbaled mirror for optometry offices. While aerospace and defense businesses can often justify the high cost of exotic, low density materials, commercial products rarely can. Also, to obtain high performance with low overall optical system weight, aspheric surfaces are often prescribed. This may drive the manufacturing process to diamond machining thus requiring the reflective side of the mirror to be a diamond machinable material. This paper summarizes the diamond machined finishing and coating of some high performance, lightweight designs using non-exotic substrates to achieve cost effective mirrors. The results indicate that these processes can meet typical aerospace and defense requirements but may also be competitive in some commercial applications.

  14. Tandem mirrors for neutron production

    SciTech Connect

    Doggett, J.N.

    1983-03-31

    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/sup -2/.

  15. Topological Mirror Superconductivity

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Kane, C. L.; Mele, E. J.

    2013-08-01

    We demonstrate the existence of topological superconductors (SCs) protected by mirror and time-reversal symmetries. D-dimensional (D=1, 2, 3) crystalline SCs are characterized by 2D-1 independent integer topological invariants, which take the form of mirror Berry phases. These invariants determine the distribution of Majorana modes on a mirror symmetric boundary. The parity of total mirror Berry phase is the Z2 index of a class DIII SC, implying that a DIII topological SC with a mirror line must also be a topological mirror SC but not vice versa and that a DIII SC with a mirror plane is always time-reversal trivial but can be mirror topological. We introduce representative models and suggest experimental signatures in feasible systems. Advances in quantum computing, the case for nodal SCs, the case for class D, and topological SCs protected by rotational symmetries are pointed out.

  16. Light, Color, and Mirrors.

    ERIC Educational Resources Information Center

    Tiburzi, Brian; Tamborino, Laurie; Parker, Gordon A.

    2000-01-01

    Describes an exercise in which students can use flashlights, mirrors, and colored paper to discover scientific principles regarding optics. Addresses the concepts of angles of incidence and reflection, colored vs. white light, and mirror images. (WRM)

  17. Attractive characteristics of mirrors

    NASA Astrophysics Data System (ADS)

    Post, R. F.; Ryutov, D. D.

    1994-12-01

    A summary of the attractive characteristics of mirror devices is presented. Recent progress in development of axisymmetric mirror devices is described. Potentialities of mirrors as a basis for D(3)He fusion power generators and high-flux neutron sources for fusion material tests are discussed.

  18. Anastigmatic three-mirror telescope

    NASA Technical Reports Server (NTRS)

    Korsch, D. G. (Inventor)

    1978-01-01

    A three-mirror telescope for extraterrestrial observations is described. An ellipsoidal primary mirror, a hyperbolic secondary mirror, and an ellipsoidal tertiary mirror, produce an image in a conveniently located finite plane for viewing.

  19. Indium Second-Surface Mirrors

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.; Hasegawa, T.

    1982-01-01

    Second-surface mirrors are formed by vapor deposition of indium onto glass. Mirrors have reflectances comparable to those of ordinary silver or aluminized mirrors and are expected to show superior corrosion resistance. Mirrors may be used in solar concentrators.

  20. Electrostatic membrane deformable mirror characterization and applications

    NASA Astrophysics Data System (ADS)

    Bush, Keith; Marrs, Anthony; Schoen, Michael

    2005-08-01

    Electrostatic Membrane Deformable Mirror (MDM) technology developed using silicon bulk micro-machining techniques offers the potential of providing low-cost, compact wavefront control systems for diverse optical system applications. Electrostatic mirror construction using bulk micro-machining allows for custom designs to satisfy wavefront control requirements for most optical systems. An electrostatic MDM consists of a thin membrane, generally with a thin metal or multi-layer high-reflectivity coating, suspended over an actuator pad array that is connected to a high-voltage driver. Voltages applied to the array elements deflect the membrane to provide an optical surface capable of correcting for measured optical aberrations in a given system. Electrostatic membrane DM designs are derived from well-known principles of membrane mechanics and electrostatics, the desired optical wavefront control requirements, and the current limitations of mirror fabrication and actuator drive electronics. MDM performance is strongly dependent on mirror diameter and air damping in meeting desired spatial and temporal frequency requirements. In this paper, we discuss characterization measurements and modeling of MDM spatial and temporal performance for different mirror designs and present application results illustrating the diverse uses of MDM technology in optical wavefront compensation systems.

  1. Water Cooled Mirror Design

    SciTech Connect

    Dale, Gregory E.; Holloway, Michael Andrew; Pulliam, Elias Noel

    2015-03-30

    This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient cooling of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.

  2. Development of Table-Top mirror trap for flute stabilization research

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2015-11-01

    Mirror traps might be viable candidates for fusion machines. These machines are technically and physically simple but suffer from the Rayleigh-Taylor-like flute instability. A new table top mirror machine was built in order to research ways to mitigate this instability. One possible solution for this problem which was researched in the past is using oscillatory fields. A description of the system and diagnostics, preliminary results and a review of the main mechanisms with which stabilization might occur are presented.

  3. Design considerations for adjustable-curvature, high-power, X-ray mirrors based on elastic bending

    NASA Astrophysics Data System (ADS)

    Howells, Malcolm R.; Lunt, David

    1993-08-01

    The use of elastic bending to form the shapes of high-power X-ray mirrors for synchrotron radiation beamlines is considered. An approach in which the bending mechanism and the mirror are cut from the same monolithic block by electric-discharge-machining techniques is especially advocated. A discussion of the theory and practical design philosophies is given that includes circular and elliptical cylinder mirrors. The influence of gravity on the mirror shape is studied with emphasis on the optimum positions for the mirror supports that, for a uniform mirror, turn out to be at a spacing equal to the mirror length divided by root three.

  4. Optical fabrication of lightweighted 3D printed mirrors

    NASA Astrophysics Data System (ADS)

    Herzog, Harrison; Segal, Jacob; Smith, Jeremy; Bates, Richard; Calis, Jacob; De La Torre, Alyssa; Kim, Dae Wook; Mici, Joni; Mireles, Jorge; Stubbs, David M.; Wicker, Ryan

    2015-09-01

    Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) 3D printing technologies were utilized to create lightweight, optical grade mirrors out of AlSi10Mg aluminum and Ti6Al4V titanium alloys at the University of Arizona in Tucson. The mirror prototypes were polished to meet the λ/20 RMS and λ/4 P-V surface figure requirements. The intent of this project was to design topologically optimized mirrors that had a high specific stiffness and low surface displacement. Two models were designed using Altair Inspire software, and the mirrors had to endure the polishing process with the necessary stiffness to eliminate print-through. Mitigating porosity of the 3D printed mirror blanks was a challenge in the face of reconciling new printing technologies with traditional optical polishing methods. The prototypes underwent Hot Isostatic Press (HIP) and heat treatment to improve density, eliminate porosity, and relieve internal stresses. Metal 3D printing allows for nearly unlimited topological constraints on design and virtually eliminates the need for a machine shop when creating an optical quality mirror. This research can lead to an increase in mirror mounting support complexity in the manufacturing of lightweight mirrors and improve overall process efficiency. The project aspired to have many future applications of light weighted 3D printed mirrors, such as spaceflight. This paper covers the design/fab/polish/test of 3D printed mirrors, thermal/structural finite element analysis, and results.

  5. Recent Results from KMAX tandem mirror experiment

    NASA Astrophysics Data System (ADS)

    Sun, Xuan; Luo, M.; Zhang, Q.; Lin, M.; Shi, P.

    2015-11-01

    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. As a versatile plasma experimental platform, KMAX is currently conducting experiments on the Alfven wave launching, electrode biasing, radio frequency heating and etc. The latest results will be presented. In the experiment of Alfven wave launching, we observed the shear Alfven waves decay into the forward and backward propagating compressional waves. And in the bias experiment we successfully extracted plasma current up to 0.5kA with biasing voltage of ~ 1kV. During biasing, the plasma density and temperature have siginificantly increasing. Preliminary results on the radio frequency heating will also be presented.

  6. LOXT mirror design study

    NASA Technical Reports Server (NTRS)

    Vanspeybroeck, L.; Antrim, W.; Boyd, D.; Giacconi, R.; Sinnamon, G.; Stille, F.

    1972-01-01

    The final report for the large orbiting X-ray telescope (LOXT) high resolution mirror design study is presented. The following tasks were performed: (1) Generation of a reference and alternate preliminary design for the LOXT high resolution mirror assembly, which will meet the LOXT scientific requirements, and are within the present state of the art of materials and fabrication techniques. (2) Measurement, in X-rays, of the scattering properties of a variety of optical flats, embodying materials, coatings, and polishing techniques which might be applicable to the flight configuration LOXT high resolution mirror. (3) Preparation of a procurement specification for a paraboloid test mirror of the size of the innermost paraboloid of the high resolution mirror assembly, including the design requirements for the reference design evolved from this preliminary design study. The results of the engineering and scientific analysis and the conclusions drawn are presented. The procurement specification for the test mirror is included.

  7. Erected mirror optical switch

    DOEpatents

    Allen, James J.

    2005-06-07

    A microelectromechanical (MEM) optical switching apparatus is disclosed that is based on an erectable mirror which is formed on a rotatable stage using surface micromachining. An electrostatic actuator is also formed on the substrate to rotate the stage and mirror with a high angular precision. The mirror can be erected manually after fabrication of the device and used to redirect an incident light beam at an arbitrary angel and to maintain this state in the absence of any applied electrical power. A 1.times.N optical switch can be formed using a single rotatable mirror. In some embodiments of the present invention, a plurality of rotatable mirrors can be configured so that the stages and mirrors rotate in unison when driven by a single micromotor thereby forming a 2.times.2 optical switch which can be used to switch a pair of incident light beams, or as a building block to form a higher-order optical switch.

  8. First Results of the Gasdynamic Mirror Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.; Rodgers, Stephen L. (Technical Monitor)

    2003-01-01

    An experimental Gasdynamic Mirror or GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the applicability of this technology for propulsion systems. This paper presents the first experimental results obtained from the machine. It is intended that this device operate at higher plasma densities and with much larger L/D ratios than previous mirror machines. The high L/D ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. The high plasma density results in the plasma behaving much more like a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. The device has been constructed to allow a considerable degree of flexibility in its configuration thus permitting the experiment to grow over time without necessitating a great deal of additional fabrication.

  9. Mesmerising mirror neurons.

    PubMed

    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. PMID:20167276

  10. Configuration and layout of the tandem mirror Fusion Power Demonstrator

    SciTech Connect

    Clarkson, I.R.; Neef, W.S.

    1983-11-30

    Studies have been performed during the past year to determine the configuration of a tandem mirror Fusion Power Demonstrator (FPD) machine capable of producing 1750 MW of fusion power. The FPD is seen as the next logical step after the Mirror Fusion Test Facility-B (MFTF-B) toward operation of a power reactor. The design of the FPD machine allows a phased construction: Phase I, a hydrogen or deuterium checkout machine; Phase 2, a DT breakeven machine; Phase 3, development of the Phase 2 machine to provide net power and act as a reactor demonstrator. These phases are essential to the development of remote handling equipment and the design of components that will ultimately be remotely handled. Phasing also permits more modes funding early in the program with some costs committed only after reaching major milestones.

  11. Business Machines

    ERIC Educational Resources Information Center

    Pactor, Paul

    1970-01-01

    The U.S. Department of Labor has projected a 106 percent increase in the demand for office machine operators over the next 10 years. Machines with a high frequency of use include printing calculators, 10-key adding machines, and key punch machines. The 12th grade is the logical time for teaching business machines. (CH)

  12. Cost effective aluminum beryllium mirrors for critical optics applications

    NASA Astrophysics Data System (ADS)

    Say, Carissa; Duich, Jack; Huskamp, Chris; White, Ray

    2013-09-01

    The unique performance of aluminum-beryllium frequently makes it an ideal material for manufacturing precision optical-grade metal mirrors. Traditional methods of manufacture utilize hot-pressed powder block in billet form which is subsequently machined to final dimensions. Complex component geometries such as lightweighted, non-plano mirrors require extensive tool path programming, fixturing, and CNC machining time and result in a high buy-to-fly ratio (the ratio of the mass of raw material purchased to the mass of the finished part). This increases the cost of the mirror structure as a significant percentage of the procurement cost is consumed in the form of machining, tooling, and scrap material that do not add value to the final part. Inrad Optics, Inc. and IBC Advanced Alloys Corp. undertook a joint study to evaluate the suitability of investment-cast Beralcast® 191 and 363 aluminum-beryllium as a precision mirror substrate material. Net shape investment castings of the desired geometry minimizes machining to just cleanup stock, thereby reducing the recurring procurement cost while still maintaining performance. The thermal stability of two mirrors, (one each of Beralcast® 191 and Beralcast® 363), was characterized from -40°F to +150°F. A representative pocketed mirror was developed, including the creation of a relevant geometry and production of a cast component to validate the approach. Information from the demonstration unit was used as a basis for a comparative cost study of the representative mirror produced in Beralcast® and one machined from a billet of AlBeMet® 162 (AlBeMet® is a registered trademark of Materion Corporation). The technical and financial results of these studies will be discussed in detail.

  13. Plasma stability studies of the gasdynamic mirror fusion propulsion experiment

    NASA Astrophysics Data System (ADS)

    Emrich, William Julius, Jr.

    The gasdynamic mirror has been proposed as a concept which could form the basis of a highly efficient fusion rocket engine. Gasdynamic mirrors differ from most other mirror type plasma confinement schemes in that they have much larger aspect ratios and operate at somewhat higher plasma densities. These differences are postulated to permit gasdynamic mirrors to confine plasmas in a stable manner without the additional complicated equipment required by low aspect ratio, low plasma density mirror machines. To verify that a gasdynamic mirror could indeed confine plasmas in a stable manner for long periods of time, a small scale experimental gasdynamic mirror was built and tested. The gasdynamic mirror which was constructed is 2.5 meters long and can accommodate plasmas up to 20 centimeters in diameter. The device is able to support mirror magnetic fields of up to two tesla and central cell magnetic fields of up to a third of a tesla. A reciprocating Langmuir probe was used to determine the radial plasma density and electron temperature profiles upon which the experimental results of this study are based. The objective of this experiment was to determine ranges of mirror ratios and plasma densities over which gasdynamic mirror could maintain stable plasmas. Theoretical analyses indicated that plasma magnetohydrodynamic instabilities were likely to occur during subsonic to supersonic flow transitions in the mirror throat region of the gasdynamic mirror. The experimental evidence based upon data derived from the Langmuir probe measurements seems to confirm this analysis. These instabilities result in a loss of plasma confinement and would almost certainly prevent the initiation of fusion reactions. The assumption that a gasdynamic mirror using a simple mirror geometry could be used as a propulsion system, therefore, appears questionable. Fairly simple modifications to the simple mirror concept are presented, however, which if incorporated into the simple mirror

  14. Stable mirror mount

    DOEpatents

    Cutburth, Ronald W.

    1990-01-01

    An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and a device for simultaneously locking the post assembly and the key assembly in a fixed position.

  15. Stable mirror mount

    DOEpatents

    Cutburth, R.W.

    1983-11-04

    An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and means for simultaneously locking said post assembly and said key assembly in a fixed position.

  16. Bronze rainbow hologram mirrors

    NASA Astrophysics Data System (ADS)

    Dawson, P.

    2006-02-01

    This project draws on holographic embossing techniques, ancient artistic conventions of bronze mirror design and modelling and casting processes to accomplish portraiture of reflection. Laser scanning, 3D computer graphics and holographic imaging are employed to enable a permanent 3D static holographic image to appear integrated with the real-time moving reflection of a viewer's face in a polished bronze disc. The disc and the figure which holds it (caryatid) are cast in bronze from a lost wax model, a technique which has been used for millennia to make personal mirrors. The Caryatid form of bronze mirror which went through many permutations in ancient Egyptian, Greece and Rome shows a plethora of expressive figure poses ranging from sleek nudes to highly embellished multifigure arrangements. The prototype of this series was made for Australian choreographer Graeme Murphy, Artistic Director of the Sydney Dance Company. Each subsequent mirror will be unique in figure and holographic imagery as arranged between artist and subject. Conceptually this project references both the modern experience of viewing mirrors retrieved from ancient tombs, which due to deterioration of the surface no longer reflect, and the functioning of Chinese Magic mirrors, which have the ability to project a predetermined image. Inspired by the metaphorical potential of these mirrors, which do not reflect the immediate reality of the viewer, this bronze hologram mirror series enables each viewer to reflect upon himself or herself observing simultaneously the holographic image and their own partially obliterated reflection.

  17. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S.; Smith, James R.; Salmon, J. Thaddeus; Monjes, Julio A.

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  18. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  19. Tandem mirror plasma confinement apparatus

    DOEpatents

    Fowler, T. Kenneth

    1978-11-14

    Apparatus and method for confining a plasma in a center mirror cell by use of two end mirror cells as positively charged end stoppers to minimize leakage of positive particles from the ends of the center mirror cell.

  20. Lightweight optical mirrors formed in single crystal substrate

    NASA Technical Reports Server (NTRS)

    Bly, Vincent T. (Inventor)

    2006-01-01

    This invention is directed to a process for manufacturing a lightweight mirror from a single crystal material, such as single crystal silicon. As a near perfect single crystal material, single crystal silicon has much lower internal stress than a conventional material. This means much less distortion of the optical surface during the light weighting process. After being ground and polished, a single crystal silicon mirror is light weighted by removing material from the back side using ultrasonic machining. After the light weighting process, the single crystal silicon mirror may be used as-is or further figured by conventional polishing or ion milling, depending on the application and the operating wavelength.

  1. Gasdynamic mirror fusion propulsion experiment

    NASA Astrophysics Data System (ADS)

    Emrich, William J.

    2001-02-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). This device would operate at much higher plasma densities and with much larger L/D ratios than previous mirror machines. Several advantages accrue from such a design. First, the high L/D ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. Second, the high plasma density will result in the plasma behaving much more like a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with ``loss cone'' microinstabilities. An experimental GDM device is currently being constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. Initial experiments are expected to commence in the late fall of 2000. .

  2. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). This device would operate at much higher plasma densities and with much larger LD ratios than previous mirror machines. Several advantages accrue from such a design. First, the high LA:) ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. Second, the high plasma density will result in the plasma behaving much more Re a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. An experimental GDM device is currently being constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. Initial experiments are expected to commence in the late fall of 2000.

  3. MILO, a mirror reflectivity code for low-energy x-rays

    SciTech Connect

    Kissel, L.

    1982-09-01

    MILO (MIrror reflectivity code, LOw energy) is an interactive fault-tolerant user-oriented code which calculates low-energy x-ray mirror reflectivity. The code combines user input with previously calculated, complex, atomic scattering factors to produce the unpolarized mirror reflectivity at various values of mirror angle and photon energy. The code can calculate the reflectivity of mirrors composed of pure elements and of homogeneous mixtures of elements. MILO is written in standard, high-machine-independent, FORTRAN 77 (ANSI X3.9-1978).

  4. Optimum selection of high performance mirror substrates for diamond finishing

    NASA Astrophysics Data System (ADS)

    Woodard, Kenneth S.; Comstock, Lovell E.; Wamboldt, Leonard; Sutherland, James S.

    2016-05-01

    Due to advances in manufacturing processes, the substrate options for high performance diamond machined mirrors are expanding. Fewer compromises have to be made to achieve the needed weight, stiffness and finish while maintaining reasonable costs. In addition to the traditional mirror materials like aluminum and beryllium, there are some less common materials that can now be included in the trade space that fill the cost and performance continuum between wrought aluminum and beryllium mirrors. Aluminum and beryllium, respectively, had been the low cost/fair performance and very high cost/very high performance bounds for substrate selection. These additional substrates provide multiple near net shape blank options and processes, mostly within these bounds, that can be considered in a mirror cost versus performance trade analysis. This paper will include a summary of some advances in manufacturing processes that provide more substrate options for diamond machined mirrors with some sample performance analysis and data. This is merged with the traditional substrate options to illustrate the now larger mirror substrate trade space. Some benchmark structural analysis is provided to back up a generic mirror design trade study.

  5. Machine Shop Grinding Machines.

    ERIC Educational Resources Information Center

    Dunn, James

    This curriculum manual is one in a series of machine shop curriculum manuals intended for use in full-time secondary and postsecondary classes, as well as part-time adult classes. The curriculum can also be adapted to open-entry, open-exit programs. Its purpose is to equip students with basic knowledge and skills that will enable them to enter the…

  6. Precision machining technology and metrology for AXAF study

    NASA Technical Reports Server (NTRS)

    Sanger, G. M.

    1983-01-01

    The optical surfaces for the Advanced X-ray Astrophysical Facility (AXAF), was studied. The applicability of precision machining technology to the manufacture of the AXAF objective mirrors and the proposed and alternative methods for manufacturing and testing; (1) the AXAF technology mirrors and (2) the AXAF high resolution mirror assembly were reviewed. Surface shape and smoothness metrology for grazing incidence X-ray surfaces and the feasibility of applying heterodyne surface profilometry to nonflat surfaces were investigated. Three sets of scattering flats with known surface profiles and microtopographic character produced by precision machining and polished precision machine surfaces were analyzed.

  7. Space Mirror Alignment System

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.; McKinney, Colin; Smythe, Robert F.; Palmer, Dean L.

    2011-01-01

    An optical alignment mirror mechanism (AMM) has been developed with angular positioning accuracy of +/-0.2 arcsec. This requires the mirror s linear positioning actuators to have positioning resolutions of +/-112 nm to enable the mirror to meet the angular tip/tilt accuracy requirement. Demonstrated capabilities are 0.1 arc-sec angular mirror positioning accuracy, which translates into linear positioning resolutions at the actuator of 50 nm. The mechanism consists of a structure with sets of cross-directional flexures that enable the mirror s tip and tilt motion, a mirror with its kinematic mount, and two linear actuators. An actuator comprises a brushless DC motor, a linear ball screw, and a piezoelectric brake that holds the mirror s position while the unit is unpowered. An interferometric linear position sensor senses the actuator s position. The AMMs were developed for an Astrometric Beam Combiner (ABC) optical bench, which is part of an interferometer development. Custom electronics were also developed to accommodate the presence of multiple AMMs within the ABC and provide a compact, all-in-one solution to power and control the AMMs.

  8. Mirror plasma apparatus

    DOEpatents

    Moir, Ralph 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.

  9. Nanolaminate deformable mirrors

    DOEpatents

    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.

  10. Nanolaminate deformable mirrors

    DOEpatents

    Papavasiliou, Alexandros P.; Olivier, Scot S.

    2010-04-06

    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.

  11. NIF small mirror mount

    SciTech Connect

    McCarville, T

    1999-07-01

    A number of small mirror mounts have been identified that meet the stringent stability, wave front, and cleanliness standards of the NIF. These requirements are similar to those required in other performance critical optical design applications. Future design teams would conserve time and effort if recognized standards were established for mirror mount design and performance characteristics. Standards for stability, physical features, wave front distortion, and cleanliness would simplify the qualification process considerably. At this point such standards are not difficult to define, as the technical support work has been performed repeatedly by mirror mount consumers and suppliers.

  12. Coarse alignment of thin-shell, segmented mirrors for Wolter-I telescopes

    NASA Astrophysics Data System (ADS)

    Donovan, Benjamin D.; Hertz, Edward; Marquez, Vanessa; McMuldroch, Stuart; Reid, Paul B.; Allured, Ryan

    2015-09-01

    The alignment of thin-shell, segmented mirrors for Wolter-I telescopes frequently involves the use of a Hartmann test. In order to get optical throughput in the Hartmann test, the mirrors must first be coarsely aligned to one another and to the metrology system. In the past, the coarse alignment of these mirrors at the Smithsonian Astrophysical Observatory has largely relied upon component machine tolerances and contact measurements with a coordinate measurement machine (CMM). This process takes time and does not produce reliable nor repeatable results. Thus, methods were developed to allow for the quick and reliable coarse alignment of thin- shell, segmented mirrors at their final locations in the mirror assembly. We present the coarse alignment system developed at the Smithsonian Astrophysical Observatory and its use in the alignment of thin-shell, segmented mirrors for the adjustable X-ray optics program.

  13. Extreme ultraviolet lithography machine

    DOEpatents

    Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.

    2000-01-01

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  14. Composite Material Mirror Testing

    NASA Technical Reports Server (NTRS)

    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.

  15. JWST Mirror Installation

    NASA Video Gallery

    The first six of 18 hexagonal shaped segments that will form NASA’s James Webb Space Telescope’s primary mirror for space observations were readied this week to begin final cryogenic testing at...

  16. The Athena Mirror

    NASA Astrophysics Data System (ADS)

    Wille, Eric

    2016-07-01

    The Athena mission (Advanced Telescope for High Energy Astrophysics) requires lightweight X-ray Wolter optics with a high angular resolution and large effective area. For achieving an effective area of 2 m^2 (at 1 keV) and an angular resolution of below 5 arcsec, the Silicon Pore Optics technology was developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the current design of the Athena mirror concentrating on the technology development status of the Silicon Pore Optics, ranging from the manufacturing of single mirror plates towards complete focusing mirror modules and their integration into the mirror structure.

  17. The Rotating Mirror.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1981-01-01

    Discusses theory of the rotating mirror, its use in measuring the velocity of the electrical signal in wires, and the velocity of light. Concludes with a description of the manometric flame apparatus developed for analyzing sound waves. (SK)

  18. Mirror Technology Roadmap

    NASA Technical Reports Server (NTRS)

    Stahl, H. Phil

    2006-01-01

    NASA's Mirror Technology Roadmap identifies specific capabilities requiring significant advances in optical fabrication and testing to enable the next generation of large-aperture space telescopes for astronomy and Earth science missions ranging from x-ray to infrared.

  19. Towards a better mirror

    NASA Technical Reports Server (NTRS)

    Hoffer, David

    1987-01-01

    Telesat's Getaway Special competition was designed to promote interest in space among high school students in Canada. The winning entry proposed the manufacture of mirrors in microgravity and to compare the optical properties of these mirrors with similar ones made on Earth. Telesat engineers designed and built the experiment which flew on the Atlantic shuttle on November 27, 1985. This paper outlines the design evolution, its implementation, the manufacture and test of the GAS and the results of the experiment.

  20. Notes on moving mirrors

    SciTech Connect

    Obadia, N.; Parentani, R.

    2001-08-15

    The Davies-Fulling (DF) model describes the scattering of a massless field by a noninertial mirror in two dimensions. In this paper, we generalize this model in two different ways. First, we consider partially reflecting mirrors. We show that the Bogoliubov coefficients relating inertial modes can be expressed in terms of the reflection factor and the transformation from inertial modes to modes at rest with respect to the mirror. In this perspective, the DF model is simply the limiting case when the reflection factor is unity for all frequencies. In the second part, we introduce an alternative model which is based on self-interactions described by an action principle. When the coupling is constant, this model can be solved exactly and gives rise to a partially reflecting mirror. The usefulness of this dynamical model lies in the possibility of switching off the coupling between the mirror and field. This allows us to obtain regularized expressions for the fluxes in situations where they are singular when using the DF model. Two examples are considered. The first concerns the flux induced by the disappearance of the reflection condition, a situation which bears some analogies with the end of the evaporation of a black hole. The second case concerns the flux emitted by a uniformly accelerated mirror.

  1. Worthwhile optical method for free-form mirrors qualification

    NASA Astrophysics Data System (ADS)

    Sironi, G.; Canestrari, R.; Toso, G.; Pareschi, G.

    2013-09-01

    We present an optical method for free-form mirrors qualification developed by the Italian National Institute for Astrophysics (INAF) in the context of the ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project which includes, among its items, the design, development and installation of a dual-mirror telescope prototype for the Cherenkov Telescope Array (CTA) observatory. The primary mirror panels of the telescope prototype are free-form concave mirrors with few microns accuracy required on the shape error. The developed technique is based on the synergy between a Ronchi-like optical test performed on the reflecting surface and the image, obtained by means of the TraceIT ray-tracing proprietary code, a perfect optics should generate in the same configuration. This deflectometry test allows the reconstruction of the slope error map that the TraceIT code can process to evaluate the measured mirror optical performance at the telescope focus. The advantages of the proposed method is that it substitutes the use of 3D coordinates measuring machine reducing production time and costs and offering the possibility to evaluate on-site the mirror image quality at the focus. In this paper we report the measuring concept and compare the obtained results to the similar ones obtained processing the shape error acquired by means of a 3D coordinates measuring machine.

  2. Treatments To Produce Stabilized Aluminum Mirrors for Cryogenic Uses

    NASA Technical Reports Server (NTRS)

    Zewari, Wahid; Barthelmy, Michael; Ohl, Raymond

    2005-01-01

    Five metallurgical treatments have been tested as means of stabilizing mirrors that are made of aluminum alloy 6061 and are intended for use in cryogenic applications. Aluminum alloy 6061 is favored as a mirror material by many scientists and engineers. Like other alloys, it shrinks upon cool-down from room temperature to cryogenic temperature. This shrinkage degrades the optical quality of the mirror surfaces. Hence, the metallurgical treatments were tested to determine which one could be most effective in minimizing the adverse optical effects of cooldown to cryogenic temperatures. Each of the five metallurgical treatments comprises a multistep process, the steps of which are interspersed with the steps of the mirror-fabrication process. The five metallurgical-treatment/fabrication.- process combinations were compared with each other and with a benchmark fabrication process, in which a mirror is made from an alloy blank by (1) symmetrical rough machining, (2) finish machining to within 0.006 in. (. 0.15 mm) of final dimensions, and finally (3) diamond turning to a mirror finish.

  3. Method for providing mirror surfaces with protective strippable polymeric film

    SciTech Connect

    Edwards, C.C.; Day, J.R.

    1980-04-22

    This invention is a method for forming a protective, strippable, elastomeric film on a highly reflective surface. The method is especially well suited for protecting diamond-machined metallic mirrors, which are susceptible not only to abrasion and mechanical damage but also to contamination and corrosion by various fluids. In a typical use of the invention, a diamond-machined copper mirror surface is coated uniformly with a solution comprising a completely polymerized and completely cured thermoplastic urethane elastomer dissolved in tetrahydrofuran. The applied coating is evaporated to dryness, forming a tough, adherent, impermeable, and transparent film which encapsulates dust and other particulates on the surface. The film may be left in place for many months. When desired, the film may be stripped intact, removing the entrapped particulates and leaving no residue on the mirror surface.

  4. Method for providing mirror surfaces with protective strippable polymeric film

    DOEpatents

    Edwards, Charlene C.; Day, Jack R.

    1980-01-01

    This invention is a method for forming a protective, strippable, elastomeric film on a highly reflective surface. The method is especially well suited for protecting diamond-machined metallic mirrors, which are susceptible not only to abrasion and mechanical damage but also to contamination and corrosion by various fluids. In a typical use of the invention, a diamond-machined copper mirror surface is coated uniformly with a solution comprising a completely polymerized and completely cured thermoplastic urethane elastomer dissolved in tetrahydrofuran. The applied coating is evaporated to dryness, forming a tough, adherent, impermeable, and transparent film which encapsulates dust and other particulates on the surface. The film may be left in place for many months. When desired, the film may be stripped intact, removing the entrapped particulates and leaving no residue on the mirror surface.

  5. Actuated Hybrid Mirror Telescope

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Redding, David; Lowman, Andrew; Cohen, David; Ohara, Catherine

    2005-01-01

    The figure depicts the planned Actuated Hybrid Mirror Telescope (AHMT), which is intended to demonstrate a new approach to the design and construction of wide-aperture spaceborne telescopes for astronomy and Earth science. This technology is also appropriate for Earth-based telescopes. The new approach can be broadly summarized as using advanced lightweight mirrors that can be manufactured rapidly at relatively low cost. More specifically, it is planned to use precise replicated metallic nanolaminate mirrors to obtain the required high-quality optical finishes. Lightweight, dimensionally stable silicon carbide (SiC) structures will support the nanolaminate mirrors in the required surface figures. To enable diffraction- limited telescope performance, errors in surface figures will be corrected by use of mirror-shape-control actuators that will be energized, as needed, by a wave-front-sensing and control system. The concepts of nanolaminate materials and mirrors made from nanolaminate materials were discussed in several previous NASA Tech Briefs articles. Nanolaminates constitute a relatively new class of materials that can approach theoretical limits of stiffness and strength. Nanolaminate mirrors are synthesized by magnetron sputter deposition of metallic alloys and/or compounds on optically precise master surfaces to obtain optical-quality reflector surfaces backed by thin shell structures. As an integral part of the deposition process, a layer of gold that will constitute the reflective surface layer is deposited first, eliminating the need for a subsequent and separate reflective-coating process. The crystallographic textures of the nanolaminate will be controlled to optimize the performance of the mirror. The entire deposition process for making a nanolaminate mirror takes less than 100 hours, regardless of the mirror diameter. Each nanolaminate mirror will be bonded to its lightweight SiC supporting structure. The lightweight nanolaminate mirrors and Si

  6. Physics of mirror systems

    SciTech Connect

    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.

  7. Innovative Magnetic Mirror Concepts

    NASA Astrophysics Data System (ADS)

    Simonen, Thomas

    2009-11-01

    In the past two decades, while magnetic mirror research in the US was curtailed, several innovations have been proposed and many have been demonstrated in Japan and Russia in the Gamma 10 and GDT experiments. These advances have led to new scientific understanding, means of overcoming previous short comings, and reconsideration of magnetic mirror systems as a modest size material testing neutron source or as a fusion- fission hybrid system. Compared to toroidal systems, the linear geometry of mirror systems has the significant advantages of easing construction, operation and maintenance, but has a less developed data base. The recent innovations include reliance on axi-symmetric mirror coils, suppression of energetic-ion cyclotron-modes with potential confined warm plasma, and sheared ExB flow stabilization of drift waves. To enable increased electron temperature, the magnetic field expansion ratio from the mirror to the end wall is increased beyond the square root of the ion to electron mass ratio. This expansion inhibits electron thermal conduction, reduces the incident wall power flux to low levels, and isolates plasma-wall interactions far from the confined plasma.

  8. Mechanical-engineering aspects of mirror-fusion technology

    SciTech Connect

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

    1982-07-15

    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.

  9. Mirror substrate fabrication techniques of low expansion glasses.

    NASA Astrophysics Data System (ADS)

    Spangenberg-Jolley, J.; Hobbs, T.

    Low expansion glasses offer many advantages as mirror blank materials due to their thermal and mechanical properties as well as the flexibility they offer in design and fabrication. Fused Silica, Corning Code 7940 and ULETM titanium silicate, Code 7971, produced by the flame hydrolysis process, are high purity and homogeneous glasses. The ability to fusion seal each of the glasses offers mirror manufacturing design freedom of shape, size and weight. Solid monolithic mirror blanks have been successfully manufactured by the hex-seal method up to 4 meters diameter and 10 meter blanks are an extension of the proven fusion techniques. Ultralightweight (10% solid weight) low expansion mirrors produced by "frit bonding" a fusion core between two precision machined plates, maintain an optical figure when exposed to thermal cycling and mechanical abuse environments.

  10. Polarized Nuclei in a Simple Mirror Fusion Reactor

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1995-01-01

    The possibility of enhancing the ratio of output to input power Q in a simple mirror machine by polarizing Deuterium-Tritium (D- T) nuclei is evaluated. Taking the Livermore mirror reference design mirror ratio of 6.54, the expected sin(sup 2) upsilon angular distribution of fusion decay products reduces immediate losses of alpha particles to the loss cone by 7.6% and alpha-ion scattering losses by approx. 50%. Based on these findings, alpha- particle confinement times for a polarized plasma should therefore be 1.11 times greater than for isotropic nuclei. Coupling this enhanced alpha-particle heating with the expected greater than 50% D- T reaction cross section, a corresponding power ratio for polarized nuclei, Q(sub polarized), is found to be 1.63 times greater than the classical unpolarized value Q(sub classical). The effects of this increase in Q are assessed for the simple mirror.

  11. Database machines

    NASA Technical Reports Server (NTRS)

    Stiefel, M. L.

    1983-01-01

    The functions and performance characteristics of data base machines (DBM), including machines currently being studied in research laboratories and those currently offered on a commerical basis are discussed. The cost/benefit considerations that must be recognized in selecting a DBM are discussed, as well as the future outlook for such machines.

  12. Cryogenic mirror analysis

    NASA Technical Reports Server (NTRS)

    Nagy, S.

    1988-01-01

    Due to extraordinary distances scanned by modern telescopes, optical surfaces in such telescopes must be manufactured to unimaginable standards of perfection of a few thousandths of a centimeter. The detection of imperfections of less than 1/20 of a wavelength of light, for application in the building of the mirror for the Space Infrared Telescope Facility, was undertaken. Because the mirror must be kept very cold while in space, another factor comes into effect: cryogenics. The process to test a specific morror under cryogenic conditions is described; including the follow-up analysis accomplished through computer work. To better illustrate the process and analysis, a Pyrex Hex-Core mirror is followed through the process from the laser interferometry in the lab, to computer analysis via a computer program called FRINGE. This analysis via FRINGE is detailed.

  13. Smart materials optical mirrors

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Rabin, Douglas M.

    2014-08-01

    We report the fabrication of imaging quality optical mirrors with smooth surfaces using carbon nanotubes embedded in an epoxy matrix. CNT/epoxy is a multifunctional or `smart' composite material that has sensing capabilities and can be made to incorporate self-actuation as well. Moreover, since the precursor is a low density liquid, large and lightweight mirrors can be fabricated by processes such as replication, spincasting, and 3D printing. The technology therefore holds promise for development of a new generation of lightweight, compact `smart' telescope mirrors with figure sensing and active or adaptive figure control. We report on measurements made of optical and mechanical characteristics. We discuss possible paths for future development.

  14. Carbon nanotube optical mirrors

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Rabin, Douglas

    2015-01-01

    We report the fabrication of imaging quality optical mirrors with smooth surfaces using carbon nanotubes (CNT) embedded in an epoxy matrix. CNT/epoxy is a multifunctional composite material that has sensing capabilities and can be made to incorporate self-actuation. Moreover, as the precursor is a low density liquid, large and lightweight mirrors can be fabricated by processes such as replication, spincasting, and three-dimensional printing. Therefore, the technology holds promise for the development of a new generation of lightweight, compact "smart" telescope mirrors with figure sensing and active or adaptive figure control. We report on measurements made of optical and mechanical characteristics, active optics experiments, and numerical modeling. We discuss possible paths for future development.

  15. Transition Metal Switchable Mirror

    SciTech Connect

    2009-01-01

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

  16. Transition Metal Switchable Mirror

    ScienceCinema

    None

    2010-01-08

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

  17. Transition Metal Switchable Mirror

    ScienceCinema

    None

    2013-05-29

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

  18. Mirror Measurement Device

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A Small Business Innovation Research (SBIR) contract led to a commercially available instrument used to measure the shape profile of mirror surfaces in scientific instruments. Bauer Associates, Inc.'s Bauer Model 200 Profilometer is based upon a different measurement concept. The local curvature of the mirror's surface is measured at many points, and the collection of data is computer processed to yield the desired shape profile. (Earlier profilometers are based on the principle of interferometry.) The system is accurate and immune to problems like vibration and turbulence. Two profilometers are currently marketed, and a third will soon be commercialized.

  19. Flat Focusing Mirror

    PubMed Central

    Cheng, Y. C.; Kicas, S.; Trull, J.; Peckus, M.; Cojocaru, C.; Vilaseca, R.; Drazdys, R.; Staliunas, K.

    2014-01-01

    The control of spatial propagation properties of narrow light beams such as divergence, focusing or imaging are main objectives in optics and photonics. In this letter, we propose and demonstrate experimentally a flat focusing mirror, based on an especially designed dielectric structure without any optical axis. More generally, it also enables imaging any light pattern in reflection. The flat focusing mirror with a transversal invariance can largely increase the applicability of structured photonic materials for light beam propagation control in small-dimension photonic circuits. PMID:25228358

  20. Flat focusing mirror.

    PubMed

    Cheng, Y C; Kicas, S; Trull, J; Peckus, M; Cojocaru, C; Vilaseca, R; Drazdys, R; Staliunas, K

    2014-01-01

    The control of spatial propagation properties of narrow light beams such as divergence, focusing or imaging are main objectives in optics and photonics. In this letter, we propose and demonstrate experimentally a flat focusing mirror, based on an especially designed dielectric structure without any optical axis. More generally, it also enables imaging any light pattern in reflection. The flat focusing mirror with a transversal invariance can largely increase the applicability of structured photonic materials for light beam propagation control in small-dimension photonic circuits. PMID:25228358

  1. Transition Metal Switchable Mirror

    SciTech Connect

    2009-08-21

    The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

  2. Next generation lightweight mirror modeling software

    NASA Astrophysics Data System (ADS)

    Arnold, William R.; Fitzgerald, Matthew; Rosa, Rubin Jaca; Stahl, H. Philip

    2013-09-01

    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 3-5 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any text editor, all the shell thickness parameters and suspension spring rates are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite

  3. Next Generation Lightweight Mirror Modeling Software

    NASA Technical Reports Server (NTRS)

    Arnold, William R., Sr.; Fitzgerald, Mathew; Rosa, Rubin Jaca; Stahl, H. Philip

    2013-01-01

    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 5-10 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any editor, all the key shell thickness parameters are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models easier.

  4. Next-Generation Lightweight Mirror Modeling Software

    NASA Technical Reports Server (NTRS)

    Arnold, William R., Sr.; Fitzgerald, Mathew; Rosa, Rubin Jaca; Stahl, Phil

    2013-01-01

    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 5-10 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any editor, all the key shell thickness parameters are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models possible

  5. Next Generation Lightweight Mirror Modeling Software

    NASA Technical Reports Server (NTRS)

    Arnold, William; Fitzgerald, Matthew; Stahl, Philip

    2013-01-01

    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 5-10 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any editor, all the key shell thickness parameters are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models possible.

  6. Paranal Receives New Mirror

    NASA Astrophysics Data System (ADS)

    2008-04-01

    A 4.1-metre diameter primary mirror, a vital part of the world's newest and fastest survey telescope, VISTA (the Visible and Infrared Survey Telescope for Astronomy) has been delivered to its new mountaintop home at Cerro Paranal, Chile. The mirror will now be coupled with a small camera for initial testing prior to installing the main camera in June. Full scientific operations are due to start early next year. VISTA will form part of ESO's Very Large Telescope facility. ESO PR Photo 10d/08 ESO PR Photo 10d/08 The VISTA Mirror The mirror arrived over the Easter weekend at the Paranal Observatory where the telescope is being assembled at an altitude of 2518m, in Chile's Atacama Desert. VISTA Project Manager Alistair McPherson from STFC's UK Astronomy Technology Centre (UK ATC) accompanied the mirror on its journey to Chile: "This is a major milestone for the VISTA project. The precious mirror was loaded on to a plane in a special cradle that used tennis balls to cushion it from impact for its arduous journey across three continents. " "The mirror had a difficult four-day journey, by air and by road. It arrived in perfect condition and now that it has been coated, we will install the mirror in the telescope with a small test camera for about four weeks testing. We plan to install the main camera in June," said the Project Scientist on VISTA, Will Sutherland of Queen Mary, University of London, UK. The VISTA 4.1-metre diameter primary mirror is the most strongly curved large mirror ever polished to such a precise and exacting surface accuracy - deviations from a perfect surface of less than 1/3000th of the thickness of a human hair. On arrival at Cerro Paranal it was safely craned into the telescope dome where it was washed and coated with a thin layer of protected silver in the facility's coating plant. Silver is the best metal for the purpose since it reflects over 98% of near-infrared light, better than the more commonly used aluminium. To date, the reflectivity

  7. Fabrication of electroless nickel plated aluminum freeform mirror for an infrared off-axis telescope.

    PubMed

    Kim, Sanghyuk; Chang, Seunghyuk; Pak, Soojong; Lee, Kwang Jo; Jeong, Byeongjoon; Lee, Gil-jae; Kim, Geon Hee; Shin, Sang Kyo; Yoo, Song Min

    2015-12-01

    Freeform mirrors can be readily fabricated by a single point diamond turning (SPDT) machine. However, this machining process often leaves mid-frequency errors (MFEs) that generate undesirable diffraction effects and stray light. In this work, we propose a novel thin electroless nickel plating procedure to remove MFE on freeform surfaces. The proposed procedure has a distinct advantage over a typical thick plating method in that the machining process can be endlessly repeated until the designed mirror surface is obtained. This is of great importance because the sophisticated surface of a freeform mirror cannot be optimized by a typical SPDT machining process, which can be repeated only several times before the limited thickness of the nickel plating is consumed. We will also describe the baking process of a plated mirror to improve the hardness of the mirror surface, which is crucial for minimizing the degradation of that mirror surface that occurs during the polishing process. During the whole proposed process, the changes in surface figures and textures are monitored and cross checked by two different types of measurements, as well as by an interference pattern test. The experimental results indicate that the proposed thin electroless nickel plating procedure is very simple but powerful for removing MFEs on freeform mirror surfaces. PMID:26836671

  8. JWST Mirror Technology Development

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2010-01-01

    Since the initial Design Studies leading to JWST, Mirror Technology was identified as a (if not the) critical capability necessary to enable the next generation of large aperture space telescopes required to achieve the science goals of imaging the earliest galaxies and proto-galaxies after the big bang. Specific telescope architectures were explored via three independent design concept studies conducted during the summer of 1996. Achieving the desired science objectives required a never before demonstrated space telescope capability, one with an 8 meter class primary mirror that is diffraction limited at 2 micrometers and operating in deep space at temperatures well below 70K. Beryllium was identified in the NASA "Yardstick" design as the preferred material because of its ability to provide stable optical performance in the anticipated thermal environment as well as its excellent specific stiffness. Because of launch vehicle constraints, two very significant architectural constraints were placed upon the telescope: segmentation and areal density. Each of these directly resulted in specific technology capability requirements. First, because the maximum launch vehicle payload fairing diameter is approximately 4.5 meters, the only way to launch an 8 meter class mirror is to segment it, fold it and deploy it on orbit - resulting in actuation and control requirements. Second, because of launch vehicle mass limits, the primary mirror allocation was only 1000 kg - resulting in a maximum areal density specification of 20 kilograms per square meter.

  9. Tandem mirror fusion research

    SciTech Connect

    Baldwin, D.E.

    1983-12-02

    The tandem mirror program has evolved considerably in the last decade. Of significance is the viable reactor concept embodied in the MARS design. An aggressive experimental program, culminating in the operation of MFTF-B in late 1986, will provide a firm basis for refining the MARS design as necessary for constructing a reactor prototype in the 1990s.

  10. Rearview Mirror Dimming Function

    ERIC Educational Resources Information Center

    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.

  11. Durable metallized polymer mirror

    DOEpatents

    Schissel, Paul O.; Kennedy, Cheryl E.; Jorgensen, Gary J.; Shinton, Yvonne D.; Goggin, Rita M.

    1994-01-01

    A metallized polymer mirror construction having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate.

  12. Durable metallized polymer mirror

    DOEpatents

    Schissel, P.O.; Kennedy, C.E.; Jorgensen, G.J.; Shinton, Y.D.; Goggin, R.M.

    1994-11-01

    A metallized polymer mirror construction is disclosed having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate. 6 figs.

  13. MEMS Actuated Deformable Mirror

    SciTech Connect

    Papavasiliou, A; Olivier, S; Barbee, T; Walton, C; Cohn, M

    2005-11-10

    This ongoing work concerns the creation of a deformable mirror by the integration of MEMS actuators with Nanolaminate foils through metal compression boning. These mirrors will use the advantages of these disparate technologies to achieve dense actuation of a high-quality, continuous mirror surface. They will enable advanced adaptive optics systems in large terrestrial telescopes. While MEMS actuators provide very dense actuation with high precision they can not provide large forces typically necessary to deform conventional mirror surfaces. Nanolaminate foils can be fabricated with very high surface quality while their extraordinary mechanical properties enable very thin, flexible foils to survive the rigors of fabrication. Precise metal compression bonding allows the attachment of the fragile MEMS actuators to the thin nanolaminate foils without creating distortions at the bond sites. This paper will describe work in four major areas: (1) modeling and design, (2) bonding development, (3) nanolaminate foil development, (4) producing a prototype. A first-principles analytical model was created and used to determine the design parameters. A method of bonding was determined that is both strong, and minimizes the localized deformation or print through. Work has also been done to produce nanolaminate foils that are sufficiently thin, flexible and flat to be deformed by the MEMS actuators. Finally a prototype was produced by bonding thin, flexible nanolaminate foils to commercially available MEMS actuators.

  14. Cosmology with liquid mirror telescopes

    NASA Technical Reports Server (NTRS)

    Hogg, David W.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    Liquid mirrors provide an exciting means to obtain large optical telescopes for substantially lower costs than conventional technologies. The liquid mirror concept has been demonstrated in the lab with the construction of a diffraction limited 1.5 m mirror. The mirror surface, using liquid mercury, forms a perfect parabolic shape when the mirror cell is rotated at a uniform velocity. A liquid mirror must be able to support a heavy mercury load with minimal flexure and have a fundamental resonant frequency that is as high as possible, to suppress the amplitude of surface waves caused by small vibrations transmitted to the mirror. To minimize the transmission of vibrations to the liquid surface, the entire mirror rests on an air bearing. This necessitates the mirror cell being lightweight, due to the limited load capabilities of the air bearing. The mirror components must also have physical characteristics which minimize the effects of thermal expansion with ambient temperature fluctuations in the observatory. In addition, the 2.7 m mirror construction is designed so that the techniques used may be readily extended to the construction of large mirrors. To attain the goals of a lightweight, rigid mirror, a composite laminant construction was used. The mirror consists of a foam core cut to the desired parabolic shape, with an accuracy of a few mm. An aluminum hub serves as an anchor for the foam and skin, and allows precise centering of the mirror on the air bearing and drive system. Several plys of Kevlar, covered in an epoxy matrix, are then applied to the foam. A final layer of pure epoxy is formed by spin casting. This final layer is parabolic to within a fraction of a mm. An aluminum ring bonded to the circumference of the mirror retains the mercury, and incorporates stainless-steel hard-points for the attachment of balance weights.

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

    SciTech Connect

    Moiseenko, V. E.; Agren, O.

    2012-06-19

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

  16. Magnet and conductor developments for the Mirror Fusion Program

    SciTech Connect

    Cornish, D.N.

    1981-10-09

    The conductor development and the magnet design and construction for the MFTF are described. Future plans for the Mirror Program and their influence on the associated superconductor development program are discussed. Included is a summary of the progress being made to develop large, high-field, multifilamentary Nb/sub 3/Sn superconductors and the feasibility of building a 12-T yin-yang set of coils for the machine to follow MFTF. In a further look into the future, possible magnetic configurations and requirements for mirror reactors are surveyed.

  17. Congenital mirror movements.

    PubMed Central

    Schott, G D; Wyke, M A

    1981-01-01

    In this report are described seven patients assessed clinically and neuropsychologically in whom mirror movements affecting predominantly the hands occurred as a congenital disorder. These mirror movements, representing a specific type of abnormal synkinesia, may arise as a hereditary condition, in the presence of a recognisable underlying neurological abnormality, and sporadically, and the seven patients provide more or less satisfactory examples of each of these three groups. Despite the apparent uniformity of the disorder, the heterogeneity and variability may be marked, examples in some of our patients including the pronounced increase in tone that developed with arm movement, and the capacity for modulation of the associated movement by alteration of neck position and bio-feedback. Various possible mechanisms are considered; these include impaired cerebral inhibition of unwanted movements, and functioning of abnormal motor pathways. Emphasis has been placed on the putative role of the direct, crossed corticomotoneurone pathways and on the unilateral and bilateral cerebral events that precede movement. PMID:7288446

  18. Dynamic coherent backscattering mirror

    PubMed Central

    Xu, M.

    2016-01-01

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation. PMID:26937296

  19. Dynamic coherent backscattering mirror

    NASA Astrophysics Data System (ADS)

    Zeylikovich, I.; Xu, M.

    2016-02-01

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

  20. Complex/Symplectic Mirrors

    SciTech Connect

    Chuang, Wu-yen; Kachru, Shamit; 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.

  1. Lightweight Substrates For Mirrors

    NASA Technical Reports Server (NTRS)

    Brown, D. Kyle

    1991-01-01

    New substrate uses conventional quasi-isotropic fabric laminate with surfacing layer of carbon-fiber paper consisting of randomly oriented chopped carbon fibers. Layered structure of fabric and paper relatively easy to manufacture. When impregnated with carbon, structure rigid and stable. Substrates of this type made quite thin, thus keeping areal weights to minimum. Mirrors of this type made faster, and cost less, than predecessors.

  2. Joined Beryllium Mirror Demonstrator

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Parsonage, Tom; Burdine, Robert (Technical Monitor)

    2001-01-01

    Fabrications of large Beryllium optical components are fundamentally limited by available facility capabilities. To overcome this limitation, NASA funded Brush Wellman Corp to study a Be joining process. Four 76 mm diameters samples and a 0.5 mm diameter Joined Beryllium Mirror Demonstrator (JBMD) were fabricated. This presentation will review the fabrication of these samples and summarize the results of their cryogenic testing at MSFCs XRCF.

  3. Mirror Substrate Fabrication Techniques Of Low Expansion Glasses

    NASA Astrophysics Data System (ADS)

    Spangenberg-Jolley, J.; Hobbs, T.

    1989-01-01

    Low expansion glasses offer many advantages as mirror blank materials due to their thermal and mechanical properties as well as the flexility they offer in design and fabrication. Fused Silica, Corning Code 7940 and ULE titanium silicate, Code 7971, produced by the flame hydrolysis process, are high purity and homogeneous glasses. Determination of the average and the variation pattern of ghe Coefficient of thermal expansion (CTE) within ULE mirror blanks (nominally 0 x 10 /°C over the 5°C to 35°C temperature interval) is readily accomplished to an accuracy of + 2 parts per billion per degree centigrade (ppb/°C) by ultrasonic measurements. The ability to fusion seal each of the glasses offers mirror manufacturing design freedom of shape, size and weight. Solid monolithic mirror blanks have been successfully manufactured by the hex-seal method up to 4 meters diameter and 10 meter blanks are an extension of the proven fusion techniques. Lightweight fusion bonded ULE mirrors, such as the primary used in the Hubble Space Telescope, are fabricated by first "welding" selected glass pieces together to form a structurally rigid core and then fusing it between two plates. Ultralightweight (10% solid weight) low expansion mirrors produced by "frit bonding" a fusion core between two precision machined plates, maintain an optical figure when exposed to thermal cycling and mechanical abuse environments.

  4. The Multiple Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Beckers, J. M.; Ulich, B. L.; Shannon, R. R.; Carleton, N. P.; Geary, J. C.; Latham, D. W.; Angel, J. R. P.; Hoffmann, W. F.; Low, F. J.; Weymann, R. J.

    The Multiple Mirror Telescope (MMT), located on top of Mount Hopkins (2600 m) in Arizona, consists of six main telescope systems, each of which is a classical Cassegrain with a 1.8 m diameter parabolic primary with focal ratio f/2.7, and a hyperbolic secondary producing a final f/31.6 for each of the individual telescopes. The most significant departures of the MMT from conventional optical telescope technology are (1) the use of light-weight 'egg-crate' mirrors, which reduced the telescope weight, (2) the use of an alt-azimuth mount, which simplifies the gravitational effects on the structure, (3) the use of a ball-bearing support rather than hydrostatic bearings, resulting in cost savings and less maintenance, (4) the use of spur gear drives rather than worm gears, and (5) the use of multiple coaligned light collectors rather than a single monolithic mirror. Early multiple objective telescopes are discussed, and the early history of the MMT project is given. The design and performance of the telescope are explained, and MMT instrumentation (spectrograph, optical design, detector, infrared photometer, SAO CCD camera) is given. Astronomical research with the telescope is discussed, along with plans for future multiple objective telescopes.

  5. Replication of lightweight mirrors

    NASA Astrophysics Data System (ADS)

    Chen, Ming Y.; Matson, Lawrence E.; Lee, Heedong; Chen, Chenggang

    2009-08-01

    The fabrication of lightweight mirror assemblages via a replication technique offers great potential for eliminating the high cost and schedule associated with the grinding and polishing steps needed for conventional glass or SiC mirrors. A replication mandrel is polished to an inverse figure shape and to the desired finish quality. It is then, coated with a release layer, the appropriate reflective layer, and followed by a laminate for coefficient of thermal expansion (CTE) tailorability and strength. This optical membrane is adhered to a mirror structural substrate with a low shrinkage, CTE tailored adhesive. Afterwards, the whole assembly is separated from the mandrel. The mandrel is then cleaned and reused for the next replication run. The ultimate goal of replication is to preserve the surface finish and figure of the optical membrane upon its release from the mandrel. Successful replication requires a minimization of the residual stresses within the optical coating stack, the curing stresses from the adhesive and the thermal stress resulting from CTE mismatch between the structural substrate, the adhesive, and the optical membrane. In this paper, the results on replicated trials using both metal/metal and ceramic/ceramic laminates adhered to light weighted structural substrates made from syntactic foams (both inorganic and organic) will be discussed.

  6. Nonplanar machines

    SciTech Connect

    Ritson, D. )

    1989-05-01

    This talk examines methods available to minimize, but never entirely eliminate, degradation of machine performance caused by terrain following. Breaking of planar machine symmetry for engineering convenience and/or monetary savings must be balanced against small performance degradation, and can only be decided on a case-by-case basis. 5 refs.

  7. Electric machine

    DOEpatents

    El-Refaie, Ayman Mohamed Fawzi; Reddy, Patel Bhageerath

    2012-07-17

    An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

  8. Permutation Machines.

    PubMed

    Bhatia, Swapnil; LaBoda, Craig; Yanez, Vanessa; Haddock-Angelli, Traci; Densmore, Douglas

    2016-08-19

    We define a new inversion-based machine called a permuton of n genetic elements, which allows the n elements to be rearranged in any of the n·(n - 1)·(n - 2)···2 = n! distinct orderings. We present two design algorithms for architecting such a machine. We define a notion of a feasible design and use the framework to discuss the feasibility of the permuton architectures. We have implemented our design algorithms in a freely usable web-accessible software for exploration of these machines. Permutation machines could be used as memory elements or state machines and explicitly illustrate a rational approach to designing biological systems. PMID:27383067

  9. LDR segmented mirror technology assessment study

    NASA Technical Reports Server (NTRS)

    Krim, M.; Russo, J.

    1983-01-01

    In the mid-1990s, NASA plans to orbit a giant telescope, whose aperture may be as great as 30 meters, for infrared and sub-millimeter astronomy. Its primary mirror will be deployed or assembled in orbit from a mosaic of possibly hundreds of mirror segments. Each segment must be shaped to precise curvature tolerances so that diffraction-limited performance will be achieved at 30 micron (nominal operating wavelength). All panels must lie within 1 micron on a theoretical surface described by the optical precipitation of the telescope's primary mirror. To attain diffraction-limited performance, the issues of alignment and/or position sensing, position control of micron tolerances, and structural, thermal, and mechanical considerations for stowing, deploying, and erecting the reflector must be resolved. Radius of curvature precision influences panel size, shape, material, and type of construction. Two superior material choices emerged: fused quartz (sufficiently homogeneous with respect to thermal expansivity to permit a thin shell substrate to be drape molded between graphite dies to a precise enough off-axis asphere for optical finishing on the as-received a segment) and a Pyrex or Duran (less expensive than quartz and formable at lower temperatures). The optimal reflector panel size is between 1-1/2 and 2 meters. Making one, two-meter mirror every two weeks requires new approaches to manufacturing off-axis parabolic or aspheric segments (drape molding on precision dies and subsequent finishing on a nonrotationally symmetric dependent machine). Proof-of-concept developmental programs were identified to prove the feasibility of the materials and manufacturing ideas.

  10. Ultraprecision machining of optics at Los Alamos

    SciTech Connect

    Rhorer, R.L.; Gauler, A.L.; Colston, E.W.; Ruhe, J.R.

    1982-01-01

    Ultraprecision machine tools are used at the Los Alamos National Laboratory for single-point diamond turning of optics and other precision parts. Measurements of a 50-mm-diam copper flat illustrate the quality of a part that can be machined on the Moore No. 3 lathe. Measurements of a 0.4-m-diam aluminum mirror with a 20-m radius of curvature are presented as an example of a part machined on the Moore No. 5 lathe. A varying frequency sine wave grating shows a type of special optical grating that can be produced using the Pneumo lathe.

  11. Ultraprecision machining of optics at Los Alamos

    SciTech Connect

    Rhorer, R.L.; Gauler, A.L.; Colston, E.W.; Ruhe, J.R.

    1981-01-01

    Ultraprecision machine tools are used at Los Alamos for single point diamond turning of optics and other precision parts. Measurements of a 50-mm-dia copper flat are used to illustrate the quality of a part which can be machined on the Moore No. 3 lathe. Measurements of a 0.4-m-dia aluminum mirror with a 20-m radius-of-curvature are presented as an example of a part machined on the Moore No. 5 lathe. A varying frequency sine wave grating is used to show a type of special optical grating which can be produced using the Pneumo lathe.

  12. Procedure for computer-controlled milling of accurate surfaces of revolution for millimeter and far-infrared mirrors

    NASA Technical Reports Server (NTRS)

    Emmons, Louisa; De Zafra, Robert

    1991-01-01

    A simple method for milling accurate off-axis parabolic mirrors with a computer-controlled milling machine is discussed. For machines with a built-in circle-cutting routine, an exact paraboloid can be milled with few computer commands and without the use of the spherical or linear approximations. The proposed method can be adapted easily to cut off-axis sections of elliptical or spherical mirrors.

  13. Fabrication of high resolution and lightweight monocrystalline silicon x-ray mirrors

    NASA Astrophysics Data System (ADS)

    Riveros, Raul E.; Kolos, Linette D.; Mazzarella, James R.; McKeon, Kevin P.; Zhang, William W.

    2015-09-01

    Monocrystalline silicon as an x-ray mirror substrate material promises significant improvements over the x- ray mirror technologies used to date, since it is mechanically stiff, stress-free, highly thermally conductive, and widely commercially available. Producing highly accurate and lightweight x-ray mirrors from monocrystalline silicon requires a unique and specialized manufacturing process capable of producing mirrors quickly and cost effectively. The identification, development, and testing of this process is the focus of the work described in this proceeding. Monocrystalline silicon blocks were obtained, and a variety of processes (wire electro-discharge machining, etching, polishing) were applied to generate an accurate and stress-free cylindrical or Wolter-I mirror surface. The mirror surface is then sliced off at a thickness of <1 mm and further processed to yield a mirror segment with <1 arcsecond RMS slope errors. Furthermore, our experiments suggest that this mirror production process requires ~2 days to produce a mirror segment and is easily integrated into a cost-reducing parallel processing scheme. Presently, there is strong evidence that the mirror production process described in this paper will meet the stringent requirements of future x-ray missions.

  14. A spectrum of shadowed mirroring.

    PubMed

    Wanamaker, Melissa C

    2012-04-01

    The central focus of this paper is to explore and extend Kohut's theory of maternal mirroring and to place it within the current context of psychoanalytic thinking. Kohut believed a child must experience "positive" mirroring from his or her mother in infancy and beyond to ensure development of a healthy self. Kohut alludes, however, to a possible situation in which the mother's face, metaphorically a mirror, can appear "faceless" to her child. From this I have inferred the concept of what I shall call "shadowed mirroring." Clinical and literary examples show that distorted, "shadowed" mirroring appears on a spectrum, with passive mirroring at one end and hostile (either verbal or nonverbal) mirroring on the other; some individuals experience both. I then consider how "shadowed mirroring," especially hostile mirroring, can be understood within the twin contexts of the overall mother-child relationship and present-day Intersubjective/Relational thinking that is both bidirectional and co-constructed. Shadowed mirroring can lead to severe personality dysfunction along the borderline-narcissistic range, as well as to difficulties in the areas of identity formation, failure of self-cohesiveness, and the blunting of certain humane qualities like empathy. PMID:22489812

  15. Comparison of Stress Relief Procedures for Cryogenic Aluminum Mirrors

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Barthelmy, Michael P.; Zewari, S. Wahid; Toland, Ronald; Mink, Ronald; Mentzell, J. Eric; Greenhouse, Matthew A.; McMann, Joseph C.; Hylan, Jason; Hagopian, John G.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Infrared Multi-Object Spectrograph (IRMOS) is a facility instrument for the Kitt Peak National Observatory Mayall Telescope (3.8 meter) and an engineering prototype for a potential design for the Next Generation Space Telescope/Multi-Object Spectrograph. IRMOS is a low-to mid-resolution (R = lambda/delta-lambda = 300-3800), near-IR (0.8-2.5 micron) spectrograph which produces simultaneous spectra of approximately 100 objects in its 2.8 x 2.0 arcmin field of view using a commercial MEMS multimirror array device. The instrument operating temperature is 80 K and the design is athermal --- the optical bench and mirrors are machined from aluminum 6061-T651. In spite of its baseline mechanical stress relief, aluminum 6061-T651 harbors some residual stress, which, unless relieved during fabrication, may relieve and distort mirror figure to unacceptable levels at the operating temperature. Other cryogenic instruments using aluminum mirrors for both ground-based and space IR astronomy have employed a variety of heat treatment formulae, with mixed results. We present the results of a test program designed to empirically determine the best stress relief procedure for the IRMOS mirrors. Identical test mirrors with spherical and flat optical prescriptions are processed with five different heat treatment formulae from the literature and compared to samples with out any additional processing. After figuring via diamond turning, the mirrors are tested for figure error and radius of curvature at room temperature and at 80 K for several thermal cycles. The heat treatment procedure for the mirrors that yielded the least and most repeatable change in figure error and radius is applied to the IRMOS mirror blanks. We correlate the results of our optical testing with heat treatment and metallographic data.

  16. Trapped Particle Instability in Kinetic Stabilized Tandem Mirror

    NASA Astrophysics Data System (ADS)

    Berk, Herbert; Pratt, Jane

    2009-11-01

    The kinetic stabilizer tandem mirror (KSTM) devised by R. F. Post (J. Fus. Energy 2007) is an innovative concept devised to stabilize a symmetric tandem mirror machines using a concept devised by D. Ryutov (Proc. of Course and Workshop, Varenna, Italy, 1987) and empirically verified in the Gas Dynamic Trap (Ivanov, et. al. Trans. Fusion Technology 39, 127, 2001). The KSTM uses the momentum flux of unconfined particles that only sample the outer end regions of the mirror where there is very favorable field line curvature. Charged ion beams at relatively low energy are externally injected into the ends and reflected out from the ends. MHD stability with a power drain less than the fusion power production can be achieved. We examine the effect of fast growing trapped particle instability (Berk et. al. Sov J. Plasma Phys. 1983) on the overall stability. In this case stability is very sensitive to the electron connection between the stabilizer and end plug.

  17. Magnet Loader for Schmidt-Cassegrain Mirror Flop Reduction

    NASA Astrophysics Data System (ADS)

    Vander Haagen, G. A.

    2006-05-01

    The struggle with mechanical and optical issues in most commercially available Schmidt-Cassegrain amateur telescopes is exacerbated by the random flop of the primary mirror as it progresses beyond the meridian. Several retrofit techniques are available to reduce this problem, including lock-down screws and collars. Such approaches all require some modification to the optical tube. This paper discusses "work-in-progress" on a Magnetic Loader for the popular C14 optical tube that locates a rare-earth magnetic assembly on the primary mirror collar thereby continuously loading the sleeve bearing assembly. This technique requires no machined modifications or parts, can be accomplished by removal of the secondary mirror, and requires no operator intervention during focusing. While the initial data looks favorable, additional development and testing over a wider range of conditions is necessary.

  18. JWST Mirror Technology Development Results

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2007-01-01

    Mirror technology is a critical enabling capability for the James Webb Space Telescope (JWST). JWST requires a Primary Mirror Segment Assembly (PMSA) that can survive launch, deploy and align itself to form a 25 square meter collecting area 6.5 meter diameter primary mirror with a 131 nm rms wavefront error at temperatures less than 50K and provide stable optical performance. At the inception of JWST in 1996, such a capability did not exist. A highly successful technology development program was initiated including the Sub-scale Beryllium Mirror Demonstrator (SBMD) and Advanced Mirror System Demonstrator (AMSD) projects. These projects along with flight program activities have matured and demonstrated mirror technology for JWST. Directly traceable prototypes or flight hardware has been built, tested and operated in a relevant environment. This paper summarizes that technology development effort.

  19. Variable focal length deformable mirror

    DOEpatents

    Headley, Daniel; Ramsey, Marc; Schwarz, Jens

    2007-06-12

    A variable focal length deformable mirror has an inner ring and an outer ring that simply support and push axially on opposite sides of a mirror plate. The resulting variable clamping force deforms the mirror plate to provide a parabolic mirror shape. The rings are parallel planar sections of a single paraboloid and can provide an on-axis focus, if the rings are circular, or an off-axis focus, if the rings are elliptical. The focal length of the deformable mirror can be varied by changing the variable clamping force. The deformable mirror can generally be used in any application requiring the focusing or defocusing of light, including with both coherent and incoherent light sources.

  20. Research on a diamond turning method for large aspherical mirrors

    NASA Astrophysics Data System (ADS)

    Han, Cheng-Shun; Zhang, Long-Jiang; Ren, Yong; Sun, Tao

    2010-05-01

    Large size aspherical optic surfaces have gained significant importance and indispensability because of their desirable properties, and the fast growing demand needs urgently efficient and economical fabrication methods. A precision diamond turning machine with rotating tool feed and fast tool servo systems special for turning large asphercial mirrors is introduced, and a method to determine the best-fit sphere for this diamond turning method is also presented. A precise in-site measurement of the processing optical mirror is planned to construct on this machine tool in order to enhance the precision and efficiency, and reduce the production cost. The lateral shearing interferometer is known for being made small and having almost common-path beams that makes insensitive to mechanical vibrations and air turbulence, so it can be very suitable for measurement on the spot.

  1. SXI Prototype mirror mount

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This final report describes the work performed from June 1993 to January 1995. The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule.

  2. A mirror to analysis.

    PubMed

    Cohen, M

    2000-12-01

    Three books written by psychiatrists for a lay audience are examined. Two are novels, and the third is a psychiatrist's account of the years of his psychiatric residency training. In all three books psychoanalysts are portrayed in negative roles, as arrogant, cold, uncaring, and even venal. The reasons why psychiatrists would portray analysis in this light are examined, and some ways in which psychoanalysts will need to re-examine their role in education and in their relationships with psychiatric colleagues in order to counteract this negative "mirror" are suggested. PMID:11143896

  3. Poco Graphite Mirror Metrology Report

    NASA Technical Reports Server (NTRS)

    Kester, Thomas J.

    2005-01-01

    Recently a lightweight mirror technology was tested at Marshall Space Flight Center's Space Optic Manufacturing Technology Center (MSFC, SOMTC). The mirror is a Poco Graphite CVD Si clad SiC substrate. It was tested for cryogenic (cryo) survivability to 20deg Kelvin in SOMTC's X-ray Calibration and Cryogenic Test Facility. The surface figure of the mirror was measured before and after cry0 cycling. The test technique and results are discussed.

  4. Mining machine

    SciTech Connect

    Parrott, G.A.

    1985-05-07

    A haulage system for a mining machine comprises a mining machine mounted on and/or guided by a conveyor and reciprocable with respect thereto, the conveyor being provided with a rack having plural rows of teeth of identical pitch, with the teeth of one row staggered with respect to an adjacent row(s), and the machine being provided with at least one power driven haulage sprocket comprising plural sets of peripherally arranged teeth of identical pitch, one set being angularly staggered with respect to an adjacent set(s), whereby one set is engageable with each row of teeth of the rack. The invention also includes a mining machine provided with such a power driven haulage sprocket, and a rack as above described and provided with end fittings for securing in articulated manner to an adjacent rack.

  5. Plasma performance study for the tandem mirror reactor

    SciTech Connect

    Boghosian, B.M.

    1980-01-01

    A computer code was developed for assessing the performance of new variations on the thermal barrier idea for tandem mirror reactors (TMR's). The code solves the particle and energy balance equations simultaneously for each species of particles in each portion of the machine. The code is thus able to determine the neutral beam and ECRH injection powers that are required to sustain an equilibrium situation, and, from these, to determine the machine's Q value. This paper focuses on the methodology and numerical algorithms used in accomplishing this solution. We plan to use this code to compare the A-cell barrier TMR with axisymmetric TMR's.

  6. Monel Machining

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Castle Industries, Inc. is a small machine shop manufacturing replacement plumbing repair parts, such as faucet, tub and ballcock seats. Therese Castley, president of Castle decided to introduce Monel because it offered a chance to improve competitiveness and expand the product line. Before expanding, Castley sought NERAC assistance on Monel technology. NERAC (New England Research Application Center) provided an information package which proved very helpful. The NASA database was included in NERAC's search and yielded a wealth of information on machining Monel.

  7. Scanning mirror for infrared sensors

    NASA Technical Reports Server (NTRS)

    Anderson, R. H.; Bernstein, S. B.

    1972-01-01

    A high resolution, long life angle-encoded scanning mirror, built for application in an infrared attitude sensor, is described. The mirror uses a Moire' fringe type optical encoder and unique torsion bar suspension together with a magnetic drive to meet stringent operational and environmental requirements at a minimum weight and with minimum power consumption. Details of the specifications, design, and construction are presented with an analysis of the mirror suspension that allows accurate prediction of performance. The emphasis is on mechanical design considerations, and brief discussions are included on the encoder and magnetic drive to provide a complete view of the mirror system and its capabilities.

  8. JWST Primary Mirror Technology Development

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2010-01-01

    Mirror Technology was identified as a (if not the) critical capability necessary to achieve the Level 1 science goals. A never before demonstrated space telescope capability was required: 6 to 8 meter class pri mary mirror, diffraction limited at 2 micrometers and operates at temperatures below 50K. Launch vehicle constraints placed significant architectural constraints: deployed/segmented primary mirror (4.5 meter fairing diameter) 20 kg/m2 areal density (PM 1000 kg mass) Such mirror technology had never been demonstrated - and did not exist

  9. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Astrophysics Data System (ADS)

    Emrich, Bill

    2000-10-01

    A gasdynamic mirror (GDM) fusion propulsion experiment is currently being constructed at the NASA Marshall Space Flight Center (MSFC) to test the feasibility of this particular type of fusion device. Because of the open magnetic field line configuration of mirror fusion devices, they are particularly well suited for propulsion system applications since they allow for the easy ejection of thrust producing plasma. Currently, the MSFC GDM is constructed in three segments. The vacuum chamber mirror segment, the plasma injector mirror segment, and the main plasma chamber segment. Enough magnets are currently available to construct up to three main plasma chamber segments. The mirror segments are also segmented such that they can be expanded to accommodate new end plugging strategies without requiring the disassembly of the entire mirror segment. The plasma for the experiment is generated in a microwave cavity located between the main magnets and the mirror magnets. Ion heating is accomplished through ambipolar diffusion. The objective of the experiment is to investigate the stability characteristics of the gasdynamic mirror and to map a region of parameter space within which the plasma can be confined in a stable steady state configuration. The mirror ratio, plasma density, and plasma ``b" will be varied over a range of values and measurements subsequently taken to determine the degree of plasma stability.

  10. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, Bill; Rodgers, Stephen L. (Technical Monitor)

    2000-01-01

    A gasdynamic mirror (GDM) fusion propulsion experiment is currently being constructed at the NASA Marshall Space Flight Center (MSFC) to test the feasibility of this particular type of fusion device. Because of the open magnetic field line configuration of mirror fusion devices, they are particularly well suited for propulsion system applications since they allow for the easy ejection of thrust producing plasma. Currently, the MSFC GDM is constructed in three segments. The vacuum chamber mirror segment, the plasma injector mirror segment, and the main plasma chamber segment. Enough magnets are currently available to construct up to three main plasma chamber segments. The mirror segments are also segmented such that they can be expanded to accommodate new end plugging strategies with out requiring the disassembly of the entire mirror segment. The plasma for the experiment is generated in a microwave cavity located between the main magnets and the mirror magnets. Ion heating is accomplished through ambipolar diffusion. The objective of the experiment is to investigate the stability characteristics of the gasdynamic mirror and to map a region of parameter space within which the plasma can be confined in a stable steady state configuration. The mirror ratio, plasma density, and plasma "b" will be varied over a range of values and measurements subsequently taken to determine the degree of plasma stability.

  11. MEMS deformable mirror embedded wavefront sensing and control system

    NASA Astrophysics Data System (ADS)

    Owens, Donald; Schoen, Michael; Bush, Keith

    2006-01-01

    Electrostatic Membrane Deformable Mirror (MDM) technology developed using silicon bulk micro-machining techniques offers the potential of providing low-cost, compact wavefront control systems for diverse optical system applications. Electrostatic mirror construction using bulk micro-machining allows for custom designs to satisfy wavefront control requirements for most optical systems. An electrostatic MDM consists of a thin membrane, generally with a thin metal or multi-layer high-reflectivity coating, suspended over an actuator pad array that is connected to a high-voltage driver. Voltages applied to the array elements deflect the membrane to provide an optical surface capable of correcting for measured optical aberrations in a given system. Electrostatic membrane DM designs are derived from well-known principles of membrane mechanics and electrostatics, the desired optical wavefront control requirements, and the current limitations of mirror fabrication and actuator drive electronics. MDM performance is strongly dependent on mirror diameter and air damping in meeting desired spatial and temporal frequency requirements. In this paper, we present wavefront control results from an embedded wavefront control system developed around a commercially available high-speed camera and an AgilOptics Unifi MDM driver using USB 2.0 communications and the Linux development environment. This new product, ClariFast TM, combines our previous Clarifi TM product offering into a faster more streamlined version dedicated strictly to Hartmann Wavefront sensing.

  12. Relay mirror experiment

    NASA Astrophysics Data System (ADS)

    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. Ultrasonic Time Reversal Mirrors

    NASA Astrophysics Data System (ADS)

    Fink, Mathias; Montaldo, Gabriel; Tanter, Mickael

    2004-11-01

    For more than ten years, time reversal techniques have been developed in many different fields of applications including detection of defects in solids, underwater acoustics, room acoustics and also ultrasound medical imaging and therapy. The essential property that makes time reversed acoustics possible is that the underlying physical process of wave propagation would be unchanged if time were reversed. In a non dissipative medium, the equations governing the waves guarantee that for every burst of sound that diverges from a source there exists in theory a set of waves that would precisely retrace the path of the sound back to the source. If the source is pointlike, this allows focusing back on the source whatever the medium complexity. For this reason, time reversal represents a very powerful adaptive focusing technique for complex media. The generation of this reconverging wave can be achieved by using Time Reversal Mirrors (TRM). It is made of arrays of ultrasonic reversible piezoelectric transducers that can record the wavefield coming from the sources and send back its time-reversed version in the medium. It relies on the use of fully programmable multi-channel electronics. In this paper we present some applications of iterative time reversal mirrors to target detection in medical applications.

  14. Mirror development for CTA

    NASA Astrophysics Data System (ADS)

    Förster, A.; Doro, M.; Brun, P.; Canestrari, R.; Chadwick, P.; Font, L.; Ghigo, M.; Lorenz, E.; Mariotti, M.; Michalowski, J.; Niemiec, J.; Pareschi, G.; Peyaud, B.; Seweryn, K.

    2009-08-01

    The Cherenkov Telescope Array (CTA), currently in its early design phase, is a proposed new project for groundbased gamma-ray astronomy with at least 10 times higher sensitivity than current instruments. CTA is planned to consist of several tens of large Imaging Atmospheric Cherenkov Telescopes (IACTs) with a combined reflective surface of up to 10,000 m2. The challenge for the future CTA array is to develop lightweight and cost efficient mirrors with high production rates, good longterm durability and adequate optical properties. The technologies currently under investigation comprise different methods of carbon fibre/epoxy based substrates, sandwich concepts with cold-slumped surfaces made of thin float glass and different structural materials like aluminum honeycomb, glass foam or PU foam inside, and aluminum sandwich structures with either diamond milled surfaces or reflective foils. The current status of the mirror development for CTA will be summarized together with investigations on the improvement of the reflective surfaces and their protection against degradation.

  15. "Mirror-Image" Errors without Mirror-Image Stimuli

    ERIC Educational Resources Information Center

    Barroso, Felix; Braine, Lila Ghent

    1974-01-01

    Young children matching the orientation of (a) identical realistic figures that could form mirror images of each other, or (b) nonidentical realistic figures that could not form mirror images, produced the same pattern of errors. The explanation proposed is a strategy of matching analogous parts of the two figures. (Author/SDH)

  16. Development of lightweight mirror elements for the Euro50 mirrors

    NASA Astrophysics Data System (ADS)

    Bennett, Harold E.; Romeo, Robert C.; Shaffer, Joseph J.; Chen, Peter C.

    2004-07-01

    New, very large telescopes with apertures of 30, 50, and 100 meters are being proposed by the astronomical community. Superpolished or ultrapolished mirrors with low scattered light levels and the use of adaptive optics for near-diffraction-limited performance would make such large telescopes a turning point in astronomy. The secondary mirror for the Euro50 will be a four meter adaptive optic made of a low expansion graphite-filled cyanate ester resin composite produced using a replica transfer technique. We have made three 1/3rd meter diameter prototype composite adaptive optic mirrors of this cyanate ester composite material. Because of the embedded graphite fibers, the composite material has a measured expansion coefficient in the 10-8 range, as has Zerodur or ULE glass. It is very much lighter, more rugged and more economical than Zerodur or ULE, and can be fabricated in weeks, not months. The Zerodur mandrels upon which these replica transfer mirrors are made are superpolished using centrifugal elutriation, so the replica surface has an rms roughness of 0.6 to 0.8 nm. It thus scatters about an order of magnitude less light than typical conventionally polished astronomical mirrors. In adaptive optic mirrors with sub-mm thick faceplates the number of plies used is insufficient to produce an isotropic surface. For mirrors 2 mm thick, with more plies, the surfaces are isotropic, and the slight astigmatism sometimes resulting from the mesh in the ply can be corrected by actuators to make them attractive mirrors. They must be supported to maintain a good optical figure over a meter diameter mirror. The support requirement may be met by using a new type of mechanical/piezoelectric actuator adjustable to a fraction of a wavelength. The mechanical actuators have a coarse adjust of over an mm and a fine adjust of less than a wavelength of light. They can be used in series with a novel type of piezoelectric actuator for final static adjustment. The low voltage, up to 2

  17. Mirror profile optimization for nano-focusing KB mirror

    SciTech Connect

    Zhang Lin; Baker, Robert; Barrett, Ray; Cloetens, Peter; Dabin, Yves

    2010-06-23

    A KB focusing mirror width profile has been optimized to achieve nano-focusing for the nano-imaging end-station ID22NI at the ESRF. The complete mirror and flexure bender assembly has been modeled in 3D with finite element analysis using ANSYS. Bender stiffness, anticlastic effects and geometrical non-linear effects have been considered. Various points have been studied: anisotropy and crystal orientation, stress in the mirror and bender, actuator resolution and the mirror-bender adhesive bonding... Extremely high performance of the mirror is expected with residual slope error smaller than 0.6 {mu}rad, peak-to-valley, compared to the bent slope of 3000 {mu}rad.

  18. Vacuum measurements on the Tandem Mirror Experiment Upgrade (TMX-U) fusion experiment

    SciTech Connect

    Calderon, M.O.; Hunt, A.L.; Lang, D.D.; Nexsen, W.E.; Pickles, W.L.; Turner, W.C.

    1983-08-12

    The gas inventory of the Tandem Mirror Experiment Upgrade (TMX-U) must be carefully controlled, if it is to successfully create various plasma configurations for thermal-barrier experiments designed to provide an improved performance for tandem-mirror experiments. This paper is a progress report on the calibration methods and pressure measurements of machine conditions deriving from recently improved neutral-beam gas control, and changes to the internal baffling geometry and the gettering system.

  19. Forming Mirrors on Composite Materials

    NASA Technical Reports Server (NTRS)

    Gauldin, R. E.; Ramohalli, K.

    1983-01-01

    Smooth coatings deposited on hard-to-polish substrates. Lightweight mirror, leaning against conventional glass mirror, consists of metallic relective layer on substrate coated with polyester resin. Smooth surface of polyester resin made by covering freshly applied resin with piece of smooth glass coated with release agent.

  20. Polishing technique for beryllium mirror

    NASA Technical Reports Server (NTRS)

    Froechtenigt, J. F.

    1976-01-01

    Performance tests, accomplished by inserting entire X ray telescope and polished mirror into vacuum line 67 m long and taking photographs of an X ray resolution source, indicate that polishing increases mirror efficiency from 0.06 percent for X rays at 0.8 nm and increases resolution from 15 to 3.75 arc-seconds.

  1. Acoustic Models of Optical Mirrors

    ERIC Educational Resources Information Center

    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.…

  2. Stroke amplifier for deformable mirrors

    PubMed Central

    Webb, Robert H.; Albanese, Marc J.; Zhou, Yaopeng; Bifano, Thomas; Burns, Stephen A.

    2010-01-01

    We demonstrate a simple optical configuration that amplifies the usable stroke of a deformable mirror. By arranging for the wavefront to traverse the deformable mirror more than once, we correct it more than once. The experimental implementation of the idea demonstrates a doubling of 2.0 and 2.04 by two different means. PMID:15495423

  3. New fabrication method for an ellipsoidal neutron focusing mirror with a metal substrate.

    PubMed

    Guo, Jiang; Takeda, Shin; Morita, Shin-ya; Hino, Masahiro; Oda, Tatsuro; Kato, Jun-ichi; Yamagata, Yutaka; Furusaka, Michihiro

    2014-10-01

    We propose an ellipsoidal neutron focusing mirror using a metal substrate made with electroless nickel-phosphorus (NiP) plated material for the first time. Electroless NiP has great advantages for realizing an ellipsoidal neutron mirror because of its amorphous structure, good machinability and relatively large critical angle of total reflection for neutrons. We manufactured the mirror by combining ultrahigh precision cutting and fine polishing to generate high form accuracy and low surface roughness. The form accuracy of the mirror was estimated to be 5.3 μm P-V and 0.8 μm P-V for the minor-axis and major-axis direction respectively, while the surface roughness was reduced to 0.2 nm rms. The effect of form error on focusing spot size was evaluated by using a laser beam and the focusing performance of the mirror was verified by neutron experiments. PMID:25322041

  4. Electrons and Mirror Symmetry

    ScienceCinema

    Kumar, Krishna

    2009-09-01

    The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

  5. Electrons and Mirror Symmetry

    SciTech Connect

    Kumar, Krishna

    2007-04-04

    The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

  6. Magnetic alignment of the Tara tandem mirror

    SciTech Connect

    Post, R.S.; Coleman, J.W.; Irby, J.H.; Olmstead, M.M.; Torti, R.P.

    1985-06-01

    Techniques developed for the alignment of high-energy accelerators have been applied to the alignment of the Tara tandem mirror magnetic confinement device. Tools used were: a transit/laser surveyor's system for establishing an invariant reference; optical scattering from ferromagnetic crystallites for establishing magnetic centers in the quadrupole anchor/transition modules; an electron-optical circle-generating wand for alignment of the solenoidal plug and central cell modules; and four differently configured electron emissive probes, including a 40-beam flux mapping e gun, for testing the alignment of the coils under vacuum. Procedures are outlined, and results are given which show that the magnetic axes of the individual coils in the Tara set have been made colinear with each other and with the reference to within +- 1.0 mm over the length of the machine between the anchor midplanes.

  7. Ultrastable mirrors made from diamond reinforced SiC composites for high precision and power applications

    NASA Astrophysics Data System (ADS)

    Akbas, M. A.; Mastrobattisto, D.; Vance, W.; Jurgaitis, P.; Aghajanian, M. K.

    2012-10-01

    Diamond reinforced reaction bonded silicon carbide composites have unique properties such as very high stiffness, low density, low thermal expansion coefficient and high thermal conductivity making them attractive materials for high precision optical and structural components. However, their use in high precision equipments was limited due to significant difficulties in high tolerance machining of these super hard composites. In this present work, machineable diamond reinforced SiC composites were fabricated through forming hybrid monolithic microstructures with diamond free machineable surfaces. The resulting machineable composites were used to produce ultra-stable mirror substrates with optional internal cooling channels for high power laser optic applications.

  8. The kinaesthetic mirror illusion: How much does the mirror matter?

    PubMed

    Chancel, Marie; Brun, Clémentine; Kavounoudias, Anne; Guerraz, Michel

    2016-06-01

    The reflection of a moving hand in a mirror positioned in the sagittal plane can create an illusion of symmetrical, bimanual movement. This illusion is implicitly presumed to be of visual origin. However, muscle proprioceptive afferents of the arm reflected in the mirror might also affect the perceived position and movement of the other arm. We characterized the relative contributions of visual and proprioceptive cues by performing two experiments. In Experiment 1, we sought to establish whether kinaesthetic illusions induced using the mirror paradigm would survive marked visual impoverishment (obtained by covering between 0 and 100 % of the mirror in 16 % steps). We found that the mirror illusion was only significantly influenced when the visual degradation was 84 % or more. In Experiment 2, we masked the muscle proprioceptive afferents of the arm reflected in the mirror by co-vibrating antagonistic muscles. We found that masking the proprioceptive afferents reduced the velocity of the illusory displacement of the other arm. These results confirm that the mirror illusion is not a purely visual illusion but emerges from a combination of congruent signals from the two arms, i.e. visual afferents from the virtually moving arm and proprioceptive afferents from the contralateral, moving arm. PMID:26790422

  9. Mirror man: a case of skilled deliberate mirror writing.

    PubMed

    McIntosh, Robert D; De Lucia, Natascia; Della Sala, Sergio

    2014-01-01

    Mirror writing is a striking behaviour that is common in children and can reemerge in adults following brain damage. Skilled deliberate mirror writing has also been reported, but only anecdotally. We provide the first quantitative study of skilled deliberate mirror writing. K.B. can write forward or backward, vertically upright or inverted, with the hands acting alone or simultaneously. K.B. is predominantly left handed, but writes habitually with his right hand. Of his writing formats, his left hand mirror writing is by far the most similar in style to his normal handwriting. When writing bimanually, he performs better when his two hands make mirror-symmetrical movements to write opposite scripts than if they move in the same direction to write similar scripts. He has no special facility for reading mirrored text. These features are consistent with prior anecdotal cases and support a motor basis for K.B.'s ability, according to which his skilled mirror writing results from the left hand execution of a low-level motor program for a right hand abductive writing action. Our methods offer a novel framework for investigating the sharing of motor representations across effectors. PMID:24593311

  10. Workout Machine

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Orbotron is a tri-axle exercise machine patterned after a NASA training simulator for astronaut orientation in the microgravity of space. It has three orbiting rings corresponding to roll, pitch and yaw. The user is in the middle of the inner ring with the stomach remaining in the center of all axes, eliminating dizziness. Human power starts the rings spinning, unlike the NASA air-powered system. Marketed by Fantasy Factory (formerly Orbotron, Inc.), the machine can improve aerobic capacity, strength and endurance in five to seven minute workouts.

  11. Point Relay Scanner Utilizing Ellipsoidal Mirrors

    NASA Technical Reports Server (NTRS)

    Manhart, Paul K. (Inventor); Pagano, Robert J. (Inventor)

    1997-01-01

    A scanning system uses a polygonal mirror assembly with each facet of the polygon having an ellipsoidal mirror located thereon. One focal point of each ellipsoidal mirror is located at a common point on the axis of rotation of the polygonal mirror assembly. As the mirror assembly rotates. a second focal point of the ellipsoidal mirrors traces out a scan line. The scanner can be utilized for scanned output display of information or for scanning information to be detected.

  12. Mirror confinement systems: Final technical report

    SciTech Connect

    Not Available

    1988-08-01

    This report contains: (1) A discussion of azimuthal asymmetrics and fluctuations in RFC-XX-M. Both lead to enhanced radial transport in RFC-XX-M, and presumably most other tandem mirror machines as well; A report on four operating modes of RFC-XX-M which were developed and studied as part of the collaboration. These operating modes were the simple tandem mode, the negative (floating) potential mode, the hot electron mode, and the ECH (electron cyclotron heating) mode; A pulsed rf heated discharge cleaning system which was developed for RFC-XX-M. This method of cleaning proved much more effective than normal glow discharge cleaning, and variations of it are currently in use on the GAMMA-10 tandem mirror and the JIPP TII-U tokamak at the Institute for Plasma Physics at Nagoya; Short descriptions of the diagnostics development and improvement done in conjunction with the work on RFC-XX-M; and a compilation of the work performed at the University of Tsukuba on GAMMA-10. Most of the effort on GAMMA-10 involved diagnostics development and improvement. 16 refs., 42 figs., 1 tab.

  13. Status on NGST Mirror Technology

    NASA Technical Reports Server (NTRS)

    Jacobson, David

    2000-01-01

    The NGST primary mirror is anticipated to be a segmented deployable optic with segment size being in the range of 1 - 3 m depending on the details of the architecture. The secondary mirror will likely be a monolith similar in size to one of the primary mirror segments. Over the past 4 years the NGST program has initiated and implemented an aggressive lightweight cryogenic mirror technology program. The program was designed to challenge and excite the optical community in reaching a new standard in production of lightweight optics. The goal was to develop optics at less than 15 kg/sq m, operational at approx. 40 K and meeting the overall NGST observatory requirement for diffraction limited performance at 2 microns. In order to meet the NGST needs, technology efforts were initiated to investigate and develop mirrors in a variety of materials, which held promise for the program. The basic technology approaches have initially targeted the production of large mirrors in the 1.2 - 2.0 m diameter range (or side-to-side distance in the case of hexagonal optics). Although this size may not be the final size of an NGST primary mirror segment, it was felt that a 1.2 - 2.0 m optic would be of sufficient size to understand the mirror material and fabrication processes which drive the cost and schedule of mirror production. The ultimate goals of the technology program are both to demonstrate mirrors meeting, the NGST performance requirements, and to establish cost and schedule credibility for producing and implementing the mirrors for the NGST flight system. Establishing cost and schedule credibility is essential to NGST which is a cost capped mission, with past program experience demonstrating that the optics will be a large portion of the total cost of the program. The first two years of the program were dedicated to understanding; the various applicable materials, funding those materials to various levels of maturity and implementing the first large mirror procurement, the

  14. Wacky Machines

    ERIC Educational Resources Information Center

    Fendrich, Jean

    2002-01-01

    Collectors everywhere know that local antique shops and flea markets are treasure troves just waiting to be plundered. Science teachers might take a hint from these hobbyists, for the next community yard sale might be a repository of old, quirky items that are just the things to get students thinking about simple machines. By introducing some…

  15. Advanced Mirror & Modelling Technology Development

    NASA Technical Reports Server (NTRS)

    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.

  16. Observational physics of mirror world

    NASA Technical Reports Server (NTRS)

    Khlopov, M. YA.; Beskin, G. M.; Bochkarev, N. E.; Pustilnik, L. A.; Pustilnik, S. A.

    1989-01-01

    The existence of the whole world of shadow particles, interacting with each other and having no mutual interactions with ordinary particles except gravity is a specific feature of modern superstring models, being considered as models of the theory of everything. The presence of shadow particles is the necessary condition in the superstring models, providing compensation of the asymmetry of left and right chirality states of ordinary particles. If compactification of additional dimensions retains the symmetry of left and right states, shadow world turns to be the mirror one, with particles and fields having properties strictly symmetrical to the ones of corresponding ordinary particles and fields. Owing to the strict symmetry of physical laws for ordinary and mirror particles, the analysis of cosmological evolution of mirror matter provides rather definite conclusions on possible effects of mirror particles in the universe. A general qualitative discussion of possible astronomical impact of mirror matter is given, in order to make as wide as possible astronomical observational searches for the effects of mirror world, being the unique way to test the existence of mirror partners of ordinary particles in the Nature.

  17. Stressed mirror polishing: finite element simulation of mirror blank deformation

    NASA Astrophysics Data System (ADS)

    Han, Yu; Lu, Lihong

    2014-08-01

    The theoretical principle of Stressed Mirror Polishing (SMP) is introduced, including the representation method of elastic deformation, the formulations of discrete bending moment and shearing force. A Finite Element Analysis (FEA) simulation model of has been set up by ANSYS software. The warping facility in this model is consisted of 36 aluminum alloy arms equally distribute on the ambit of mirror blank. Two forces are applied on each arm to provide bending moment and shearing force. Taking type 82 segment of Thirty Meters Telescope (TMT) primary mirror for example, a FEA simulation of mirror blank deformation has been performed. Simulation result shows that, the deformation error is 33μm PV. The theoretical deformation PV value is 205μm and the simulation deformation PV value is 172μm, converging rate reaches to 0.84 in a single warping cycle. After three or four warping cycles, the residue error may converge into 1μm.

  18. Kodak AMSD Mirror Development Program

    NASA Technical Reports Server (NTRS)

    Matthews, Gary; Dahl, Roger; Barrett, David; Bottom, John; Russell, Kevin (Technical Monitor)

    2002-01-01

    The Advanced Mirror System Demonstration Program is developing minor technology for the next generation optical systems. Many of these systems will require extremely lightweight and stable optics due to the overall size of the primary mirror. These segmented, deployable systems require new technology that AMSD is developing. The on-going AMSD program is a critical enabler for Next Generation Space Telescope (NGST) which will start in 2002. The status of Kodak's AMSD mirror and future plans will be discussed with respect to the NGST program.

  19. JWST NIRCam flight mirror assemblies

    NASA Astrophysics Data System (ADS)

    Mammini, Paul V.; Holmes, Howard C.; Huff, Lynn; Jacoby, Mike S.; Lopez, Frank

    2011-10-01

    The Near Infrared Camera (NIRCam) instrument for NASA's James Webb Space Telescope (JWST) has an optical prescription which includes numerous fold mirror assemblies. The instrument will operate at 35K after experiencing launch loads at ~293K. The optic mounts must accommodate all associated thermal and mechanical stresses, plus maintain exceptional optical quality during operation. Lockheed Martin Space Systems Company (LMSSC) conceived, designed, analyzed, assembled, tested, and integrated the mirror assemblies for the NIRCam instrument. This paper covers the design, analysis, assembly, and test of two of the instruments key fold mirrors.

  20. Polarimetry with multiple mirror telescopes

    NASA Technical Reports Server (NTRS)

    West, S. C.

    1986-01-01

    The polarizations of multiple mirror telescopes are calculated using Mueller calculus. It is found that the Multiple Mirror Telescope (MMT) produces a constant depolarization that is a function of wavelength and independent of sky position. The efficiency and crosstalk are modeled and experimentally verified. The two- and four-mirror new generation telescopes are found to produce sinusoidal depolarization for which an accurate interpretation of the incident Stokes vector requires inverse matrix calculations. Finally, the depolarization of f/1 paraboloids is calculated and found to be less than 0.1 percent at 3000 A.

  1. Evanescent Wave Atomic Mirror

    NASA Astrophysics Data System (ADS)

    Ghezali, S.; Taleb, A.

    2008-09-01

    A research project at the "Laboratoire d'électronique quantique" consists in a theoretical study of the reflection and diffraction phenomena via an atomic mirror. This poster presents the principle of an atomic mirror. Many groups in the world have constructed this type of atom optics experiments such as in Paris-Orsay-Villetaneuse (France), Stanford-Gaithersburg (USA), Munich-Heidelberg (Germany), etc. A laser beam goes into a prism with an incidence bigger than the critical incidence. It undergoes a total reflection on the plane face of the prism and then exits. The transmitted resulting wave out of the prism is evanescent and repulsive as the frequency detuning of the laser beam compared to the atomic transition δ = ωL-ω0 is positive. The cold atomic sample interacts with this evanescent wave and undergoes one or more elastic bounces by passing into backward points in its trajectory because the atoms' kinetic energy (of the order of the μeV) is less than the maximum of the dipolar potential barrier ℏΩ2/Δ where Ω is the Rabi frequency [1]. In fact, the atoms are cooled and captured in a magneto-optical trap placed at a distance of the order of the cm above the prism surface. The dipolar potential with which interact the slow atoms is obtained for a two level atom in a case of a dipolar electric transition (D2 Rubidium transition at a wavelength of 780nm delivered by a Titane-Saphir laser between a fundamental state Jf = l/2 and an excited state Je = 3/2). This potential is corrected by an attractive Van der Waals term which varies as 1/z3 in the Lennard-Jones approximation (typical atomic distance of the order of λ0/2π where λ0 is the laser wavelength) and in 1/z4 if the distance between the atom and its image in the dielectric is big in front of λ0/2π. This last case is obtained in a quantum electrodynamic calculation by taking into account an orthornormal base [2]. We'll examine the role of spontaneous emission for which the rate is inversely

  2. Development of SiC ultra light mirror for large space telescope and for extremely huge ground based telescope

    NASA Astrophysics Data System (ADS)

    Ebizuka, Noboru; Dai, Yutang; Eto, Hiroaki; Lin, Weimin; Ebisuzaki, Toshikazu; Omori, Hitoshi; Handa, Thoshikazu; Takami, Hideki; Takahashi, Yoshiyuki

    2003-02-01

    Ultra lightweight mirrors of silicon carbide (SiC) are used for a large number of space telescopes, and SiC is also candidate as hopeful material for segmented mirrors of the next generation ground based telescopes from 20 to 100 m in diameter. However, an SiC mirror is difficult to shape because the material is very hard and brittle. We are developing an SiC mirror by means of an ultra-precision rotary grinding machine (800 mm in diameter) and the ELID (ELectrolytic In-process Dressing) grinding method. The method is suitable for fabrications of very hard materials, such as crystalline silicon and sapphire, ceramics, glasses, hard metals and so on. In this study, we present results of test fabrication for the SiC mirrors by means of ELID grinding method and evaluations of the profile deformation of the lightweight mirrors by using FEM simulation method.

  3. Drilling Machines: Vocational Machine Shop.

    ERIC Educational Resources Information Center

    Thomas, John C.

    The lessons and supportive information in this field tested instructional block provide a guide for teachers in developing a machine shop course of study in drilling. The document is comprised of operation sheets, information sheets, and transparency masters for 23 lessons. Each lesson plan includes a performance objective, material and tools,…

  4. Tinbergen on mirror neurons

    PubMed Central

    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. PMID:24778376

  5. Responder fast steering mirror

    NASA Astrophysics Data System (ADS)

    Bullard, Andrew; Shawki, Islam

    2013-09-01

    Raytheon Space and Airborne Systems (SAS) has designed, built and tested a 3.3-inch diameter fast steering mirror (FSM) for space application. This 2-axis FSM operates over a large angle (over 10 degree range), has a very high servo bandwidth (over 3.3 Khz closed loop bandwidth), has nanoradian-class noise, and is designed to support microradian class line of sight accuracy. The FSM maintains excellent performance over large temperature ranges (which includes wave front error) and has very high reliability with the help of fully redundant angle sensors and actuator circuits. The FSM is capable of achieving all its design requirements while also being reaction-compensated. The reaction compensation is achieved passively and does not need a separate control loop. The FSM has undergone various environmental testing which include exported forces and torques and thermal vacuum testing that support the FSM design claims. This paper presents the mechanical design and test results of the mechanism which satisfies the rigorous vacuum and space application requirements.

  6. Responder fast steering mirror

    NASA Astrophysics Data System (ADS)

    Bullard, Andrew; Shawki, Islam

    2013-10-01

    Raytheon Space and Airborne Systems (SAS) has designed, built and tested a 3.3-inch diameter fast steering mirror (FSM) for space application. This 2-axis FSM operates over a large angle (over 10 degree range), has a very high servo bandwidth (over 3.3 Khz closed loop bandwidth), has nanoradian-class noise, and is designed to support microradian class line of sight accuracy. The FSM maintains excellent performance over large temperature ranges (which includes wave front error) and has very high reliability with the help of fully redundant angle sensors and actuator circuits. The FSM is capable of achieving all its design requirements while also being reaction-compensated. The reaction compensation is achieved passively and does not need a separate control loop. The FSM has undergone various environmental testing which include exported forces and torques and thermal vacuum testing that support the FSM design claims. This paper presents the mechanical design and test results of the mechanism which satisfies the rigorous vacuum and space application requirements.

  7. Tandem-mirror technology demonstration facility

    SciTech Connect

    Fowler, T.K.; Logan, B.G.

    1981-09-18

    Preliminary calculations at LLNL indicate that a Technology Demonstration Facility (TDF) consisting of a tandem mirror machine about the size of TMX could begin providing fusion nuclear engineering data as early as 1988. With high density operation based on physics already demonstrated in TMX, this machine would produce 12 MW of DT neutrons in steady-state from a plasma column 0.08 m in radius and 8 m in length. Allowing space for neutral beam injectors at each end of the column, this would permit testing of blanket modules and components at 1 MW/m/sup 2/ neutron wall load over a cylindrical surface 8 m/sup 2/ in area at a radius of 0.25 m; or one could irradiate thousands of small samples at 2 MW/m/sup 2/ at r = 0.125 m (4 m/sup 2/ area). With improved end-plug physics to be tested in TMX-Upgrade in 1982-83, the wall load at 0.25 m could be increased to 2 MW/m/sup 2/ (4 MW/m/sup 2/ at r = 0.125 m). Construction of the TDF could begin in FY84 and be completed in 4 to 5 years, at a cost roughly estimated as $700M in '81 dollars including engineering and 30% contingency.

  8. A monolithic deformable mirror with latchable mechanical actuation (LATCHAMAN) for space-borne telescopes

    NASA Astrophysics Data System (ADS)

    Enya, Keigo; Kataza, Hirokazu; Fukushima, Mitsuhiro; Mitsui, Kenji; Okada, Norio; Iwashita, Hikaru; Haze, Kanae; Takahashi, Aoi; Kotani, Takayuki; Yamamuro, Tomoyasu; Kobayashi, Hitomi

    2014-09-01

    We present the concept, design, fabrication, and evaluation of a new deformable mirror (DM), which is latchable, compact, and designed to be applicable for cryogenic environments. The main body of a prototype DM was fabricated from a monolithic cuboid of aluminum using wire electrical discharge machining (EDM). A flexible structure was constructed inside the block by 3-dimensionally crossed hollowing using the EDM. The prototype has 6 × 6 channels, and its volume is 27 mm × 27 mm × 30 mm. The mirror was formed on the surface of the aluminum block using a highprecision NC lathe. The surface figure of the mirror was evaluated and 34 nm rms was obtained. The evaluated surface roughness for the center and off-center areas of the mirror was 9.2 nm rms and 7.6 nm rms, respectively Screws set at the back of the block deform the mirror via springs and the internal flexible structure. We present our first demonstration of deformation of the mirror carried out at ambient temperature. The relationship between the displacement of the screws and the deformation of the mirror was evaluated. Consequently, a linear relationship was confirmed, and no significant hysteresis was found. The application of such mirrors to telescopes used for various different objectives is discussed. We conclude that a DM based on our concept can be used for wavefront correction of space-borne telescopes, especially in the infrared wavelength region.

  9. The magic of relay mirrors

    NASA Astrophysics Data System (ADS)

    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.

  10. JWST Primary Mirror Installation Complete

    NASA Video Gallery

    Completing the assembly of the primary mirror, which took place at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is a significant milestone and the culmination of over a decade of desi...

  11. Paper like cholesteric interferential mirror.

    PubMed

    Petriashvili, Gia; Japaridze, Kokhta; Devadze, Lali; Zurabishvili, Cisana; Sepashvili, Nino; Ponjavidze, Nino; De Santo, Maria P; Matranga, Mario A; Hamdi, Ridha; Ciuchi, Federica; Barberi, Riccardo

    2013-09-01

    A new type of flexible cholesteric liquid crystal mirror is presented. The simple and effective method for the deposition of a cholesteric mixture on a paper substrate and the particular design of the device give a homogeneous alignment of the cholesteric texture providing mirrors with an intense and uniform light reflectance. A desired polarization state for the reflected light, linear or circular, can be easily obtained varying the thickness and optical anisotropy of the polymer cover film. By using non-azobenzene based photosensitive materials a permanent array of RGB mirrors with high reflectivity can be obtained on the same device. Paper like reflective mirrors are versatile and they can find applications in reflective displays, adaptive optics, UV detectors and dosimeters, information recording, medicine and IR converters. PMID:24103954

  12. Morphing of Segmented Bimorph Mirrors

    NASA Astrophysics Data System (ADS)

    Rodrigues, Gonçalo; Bastaits, Renaud; Preumont, André

    2010-08-01

    Atmospheric turbulence compensation for the next generation of terrestrial telescopes (30-40 m diameter) will require deformable mirrors of increasing size and a number of actuators reaching several thousands. However, the mere extrapolation of existing designs leads to complicated and extremely expensive mirrors. This article discusses an alternative solution based on the use of segmented identical hexagonal bimorph mirrors. This allows to indefinitely increase the degree of correction while maintaining the first mechanical resonance at the level of a single segment, and shows an increase in price only proportional to the number of segments. Extensive simulations using random turbulent screens show that the segmentation produces only moderate reductions of the Strehl number, compared to a monolithic bimorph mirror with the same number of actuators (S = 0.86 instead of S = 0.89 in this study).

  13. JWST Secondary Mirror Deploy Timelapse

    NASA Video Gallery

    Setting up NASA's James Webb Space Telescope's secondary mirror in space will require special arms that resemble a tripod that was recently demonstrated in a NASA cleanroom. TRT: 1:25 / Credit: NAS...

  14. Charging machine

    DOEpatents

    Medlin, John B.

    1976-05-25

    A charging machine for loading fuel slugs into the process tubes of a nuclear reactor includes a tubular housing connected to the process tube, a charging trough connected to the other end of the tubular housing, a device for loading the charging trough with a group of fuel slugs, means for equalizing the coolant pressure in the charging trough with the pressure in the process tubes, means for pushing the group of fuel slugs into the process tube and a latch and a seal engaging the last object in the group of fuel slugs to prevent the fuel slugs from being ejected from the process tube when the pusher is removed and to prevent pressure liquid from entering the charging machine.

  15. Fullerene Machines

    NASA Technical Reports Server (NTRS)

    Globus, Al; Saini, Subhash (Technical Monitor)

    1998-01-01

    Fullerenes possess remarkable properties and many investigators have examined the mechanical, electronic and other characteristics of carbon SP2 systems in some detail. In addition, C-60 can be functionalized with many classes of molecular fragments and we may expect the caps of carbon nanotubes to have a similar chemistry. Finally, carbon nanotubes have been attached to t he end of scanning probe microscope (Spill) tips. Spills can be manipulated with sub-angstrom accuracy. Together, these investigations suggest that complex molecular machines made of fullerenes may someday be created and manipulated with very high accuracy. We have studied some such systems computationally (primarily functionalized carbon nanotube gears and computer components). If such machines can be combined appropriately, a class of materials may be created that can sense their environment, calculate a response, and act. The implications of such hypothetical materials are substantial.

  16. Fullerene Machines

    NASA Technical Reports Server (NTRS)

    Globus, Al; Saini, Subhash

    1998-01-01

    Recent computational efforts at NASA Ames Research Center and computation and experiment elsewhere suggest that a nanotechnology of machine phase functionalized fullerenes may be synthetically accessible and of great interest. We have computationally demonstrated that molecular gears fashioned from (14,0) single-walled carbon nanotubes and benzyne teeth should operate well at 50-100 gigahertz. Preliminary results suggest that these gears can be cooled by a helium atmosphere and a laser motor can power fullerene gears if a positive and negative charge have been added to form a dipole. In addition, we have unproven concepts based on experimental and computational evidence for support structures, computer control, a system architecture, a variety of components, and manufacture. Combining fullerene machines with the remarkable mechanical properties of carbon nanotubes, there is some reason to believe that a focused effort to develop fullerene nanotechnology could yield materials with tremendous properties.

  17. Production of Near-Mirror Surface Quality by Precision Grinding

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin; Krantz, Timothy

    2003-01-01

    Mechanical components such as gears and bearings operate with the working surfaces in intimate contact with a mating part. The performance of such components will be influenced by the quality of the working surface. In general, a smoother surface will perform better than a rougher surface since the lubrication conditions are improved. For example, surfaces with a special near-mirror quality finish of low roughness performed better than ground surfaces when tested using a block-on-ring arrangement. Bearings with near-mirror quality have been tested and analyzed; lower running torques were measured and improved fatigue life was anticipated. Experiments have been done to evaluate the performance of gears with improved, low roughness surface finishing. The measured performance improvements include an increased scuffing (scoring) load capacity by a factor of 1.6, a 30-percent reduction of gear tooth running friction, and longer fatigue lives by a factor of about four. One can also anticipate that near-mirror quality surface finishing could improve the performance of other mechanical components such as mechanical seals and heavily loaded journal bearings. Given these demonstrated benefits, capable and economical methods for the production of mechanical components with near-mirror quality surfaces are desired. One could propose the production of near-mirror quality surfaces by several methods such as abrasive polishing, chemical assisted polishing, or grinding. Production of the surfaces by grinding offers the possibility to control the macro-geometry (form), waviness, and surface texture with one process. The present study was carried out to investigate the possibility of producing near-mirror quality surfaces by grinding. The present study makes use of a specially designed grinding machine spindle to improve the surface quality relative to the quality produced when using a spindle of conventional design.

  18. High flux and high quality FEL resonator mirrors

    SciTech Connect

    Anthony, F.M.; Mistretta, A.L.; Tonnessen, T.W. )

    1989-08-01

    The Free Electron Laser Cooled Mirror Technology Development Program was highly successful; this technology can be applied to cooled silicon mirror requirements for RF linac FEL's. Designs were developed for a 100 cm hyperboloid subjected to a peak absorbed flux of 1000 w/cm[sup 2] and for a 50 cm paraboloid with an absorbed peak flux of 500 w/cm[sup 2]. Although the design concepts were essentially the same detailed implementation was somewhat different for each of the mirrors. Both designs incorporated variable geometry and internal flow tailoring over the planform area so as to produce a near spherical distortion response to the input Gaussian power distribution. This enhanced correctability of the overall distortion such that the net distortion was only 0.2 A/(w/cm[sup 2]) after correction for sphere, piston and bit as compared to a design goal of 0.5 A/(w/cm[sup 2]). Structural integrity testing of small samples, that incorporated internal geometries of both types of mirrors, verified the adequacy of the designs. Fabrication of the different types of test specimens demonstrated the producibility of the configurations. Planform bonding of manifold simulations was successful; they type of bonding is required to produce a 50 cm diameter circular silicon mirror from boules that are somewhat smaller in diameter. After planform bonding of preforms they were machined, etched, assembled into pressure test specimens, and burst pressure tested. The average burst pressure of 1550 psig was somewhat stronger than early SHOP specimens of the same configuration but somewhat lower than more recently produced specimens which evidenced burst pressure strengths of 2500 psig. Demonstrated planform bond strengths are more than adequate for the mirrors of interest, better performance can be expected as the bonding precess is refined. These, and the other experimental results indicate the large factor of safety provided by the designs.

  19. High flux and high quality FEL resonator mirrors. Final report

    SciTech Connect

    Anthony, F.M.; Mistretta, A.L.; Tonnessen, T.W.

    1989-08-01

    The Free Electron Laser Cooled Mirror Technology Development Program was highly successful; this technology can be applied to cooled silicon mirror requirements for RF linac FEL`s. Designs were developed for a 100 cm hyperboloid subjected to a peak absorbed flux of 1000 w/cm{sup 2} and for a 50 cm paraboloid with an absorbed peak flux of 500 w/cm{sup 2}. Although the design concepts were essentially the same detailed implementation was somewhat different for each of the mirrors. Both designs incorporated variable geometry and internal flow tailoring over the planform area so as to produce a near spherical distortion response to the input Gaussian power distribution. This enhanced correctability of the overall distortion such that the net distortion was only 0.2 A/(w/cm{sup 2}) after correction for sphere, piston and bit as compared to a design goal of 0.5 A/(w/cm{sup 2}). Structural integrity testing of small samples, that incorporated internal geometries of both types of mirrors, verified the adequacy of the designs. Fabrication of the different types of test specimens demonstrated the producibility of the configurations. Planform bonding of manifold simulations was successful; they type of bonding is required to produce a 50 cm diameter circular silicon mirror from boules that are somewhat smaller in diameter. After planform bonding of preforms they were machined, etched, assembled into pressure test specimens, and burst pressure tested. The average burst pressure of 1550 psig was somewhat stronger than early SHOP specimens of the same configuration but somewhat lower than more recently produced specimens which evidenced burst pressure strengths of 2500 psig. Demonstrated planform bond strengths are more than adequate for the mirrors of interest, better performance can be expected as the bonding precess is refined. These, and the other experimental results indicate the large factor of safety provided by the designs.

  20. Induction machine

    DOEpatents

    Owen, Whitney H.

    1980-01-01

    A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.

  1. Large Scale Nanolaminate Deformable Mirror

    SciTech Connect

    Papavasiliou, A; Olivier, S; Barbee, T; Miles, R; Chang, K

    2005-11-30

    This work concerns the development of a technology that uses Nanolaminate foils to form light-weight, deformable mirrors that are scalable over a wide range of mirror sizes. While MEMS-based deformable mirrors and spatial light modulators have considerably reduced the cost and increased the capabilities of adaptive optic systems, there has not been a way to utilize the advantages of lithography and batch-fabrication to produce large-scale deformable mirrors. This technology is made scalable by using fabrication techniques and lithography that are not limited to the sizes of conventional MEMS devices. Like many MEMS devices, these mirrors use parallel plate electrostatic actuators. This technology replicates that functionality by suspending a horizontal piece of nanolaminate foil over an electrode by electroplated nickel posts. This actuator is attached, with another post, to another nanolaminate foil that acts as the mirror surface. Most MEMS devices are produced with integrated circuit lithography techniques that are capable of very small line widths, but are not scalable to large sizes. This technology is very tolerant of lithography errors and can use coarser, printed circuit board lithography techniques that can be scaled to very large sizes. These mirrors use small, lithographically defined actuators and thin nanolaminate foils allowing them to produce deformations over a large area while minimizing weight. This paper will describe a staged program to develop this technology. First-principles models were developed to determine design parameters. Three stages of fabrication will be described starting with a 3 x 3 device using conventional metal foils and epoxy to a 10-across all-metal device with nanolaminate mirror surfaces.

  2. FAME: Freeform Active Mirrors Experiment

    NASA Astrophysics Data System (ADS)

    Hugot, Emmanuel; Agocs, Tibor; Challita, Zalpha; Jasko, Attila; Kroes, Gabby; Banyai, Evelin; Miller, Chris; Taylor, William; Schnetler, Hermine; Venema, Lars

    2014-07-01

    This paper discusses the development of a demonstrator freeform active mirror for future astronomical instruments both on Earth and in space. It consists of a system overview and progress in various areas of technology in the building blocks of the mirror: an extreme freeform thin face sheet, an active array, design tools and the metrology and control of the system. The demonstrator aims to investigate the applicability of the technique in high end astronomical systems, also for space and cryogenically.

  3. High temperature current mirror amplifier

    DOEpatents

    Patterson, III, Raymond B.

    1984-05-22

    A high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg.

  4. Ultraviolet-Induced Mirror Degradation

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.; Hasegawa, T. T.; Cleland, E. L.

    1982-01-01

    Recent tests of second-surface mirrors show that ultraviolet radiation penetrates glass and metalized zone and impinges upon backing paint. According to report, many backing materials are degraded by ultraviolet radiation. Mirror corrosion is a serious problem in solar-energy collection systems. Effects of UV on polymeric materials have been studied, and in general, all are degraded by UV. Polymers most resistant to UV radiation are polyimides.

  5. Some Reflections on Plane Mirrors and Images.

    ERIC Educational Resources Information Center

    Galili, Igal; And Others

    1991-01-01

    Discusses the following questions based on the assumption that students' personal experiences and prior beliefs about plane mirrors can promote interesting discussions: (1) How mirror images are formed? (2) Why doesn't paper behave like a mirror? (3) Does a mirror left-right reverse objects? and (4) Why are corner images of two perpendicular…

  6. EAGLE: relay mirror technology development

    NASA Astrophysics Data System (ADS)

    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.

  7. Polymer glazing for silver mirrors

    SciTech Connect

    Neidlinger, H H; Schissel, P

    1985-07-01

    This paper reports on an evaluation and modification of polymeric glazings to protect silver mirrors. The mirrors were made using Corning 7809 glass as a substrate onto which a thin silver film is deposited. The modified polymeric films are then cast from solution onto the silver. The mirrors were characterized by measuring the hemispherical reflectance and the specular reflectance at 660 nm and selected acceptance angles (7.5 mrad or 3.5 mrad). The mirrors were exposed to environmental degradation using accelerated weathering devices and outdoor exposure. Empirical evidence has demonstrated that polymethylmethacrylate is a stable polymer in a terrestrial environment, but the polymer does not provide adequate protection for the silver reflector. The crucial role in degradation played by ultraviolet (uv) light is shown by several experimental results. It has been demonstrated that uv stabilizers added to the polymer improve the weatherability of mirrors. The relative effectiveness of different stabilizers will be discussed in terms of the weathering modes, retention of optical properties, and effectiveness of the additives. The process for silver deposition influences the reflectance of silver mirrors, and the optical properties depend on subtle relationships between the metallization and the dielectric (polymeric) films that are in contact with the silver.

  8. National Mirror Fusion Program Plan

    SciTech Connect

    Gerich, C.A.

    1982-08-01

    This Plan is current as of August 1982. The major milestones listed herein represent an aggressive, success-oriented program paced primarily by technical results. Consistent with applicable government policies and the overall program planning of the Department's Office of Fusion Energy, this Plan assumes approval of the Mirror Program's next major step beyond MFTF-B - a deuterium-tritium (D-T) burning engineering reactor called the Fusion Power Demonstration (FPD) facility (formerly the Tandem Mirror Next Step). The near-term goal of the tandem mirror program is to lay the scientific and technical groundwork for an economically attractive, D-T fusion reactor design before the end of the 1980s. Construction of the FPD facility based on the tandem mirror could be initited around 1988. A second phase, complete with a nuclear power blanket demonstration, could be initiated in the mid-1990s, based on nuclear engineering data from a facility such as the Technology Demonstration Facility (TDF) described below. The outline of an acceptable tandem mirror reactor (TMR) design was first published in 1981, and will be further developed and described in the Mirror Advanced Reactor Study (MARS) during FY 1982-1983.

  9. Directly polished lightweight aluminum mirror

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

    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. The collaboration between optical- and mechanical designers at Astron led to new design philosophies and strategies. 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 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.

  10. High stroke pixel for a deformable mirror

    DOEpatents

    Miles, Robin R.; Papavasiliou, Alexandros P.

    2005-09-20

    A mirror pixel that can be fabricated using standard MEMS methods for a deformable mirror. The pixel is electrostatically actuated and is capable of the high deflections needed for spaced-based mirror applications. In one embodiment, the mirror comprises three layers, a top or mirror layer, a middle layer which consists of flexures, and a comb drive layer, with the flexures of the middle layer attached to the mirror layer and to the comb drive layer. The comb drives are attached to a frame via spring flexures. A number of these mirror pixels can be used to construct a large mirror assembly. The actuator for the mirror pixel may be configured as a crenellated beam with one end fixedly secured, or configured as a scissor jack. The mirror pixels may be used in various applications requiring high stroke adaptive optics.

  11. On time reversal mirrors

    NASA Astrophysics Data System (ADS)

    Fannjiang, Albert C.

    2009-09-01

    The concept of time reversal (TR) of a scalar wave is reexamined from basic principles. Five different time-reversal mirrors (TRMs) are introduced and their relations are analyzed. For the boundary behavior, it is shown that for a paraxial wave only the monopole TR scheme satisfies the exact boundary condition while for the spherical wave only the MD-mode TR scheme satisfies the exact boundary condition. The asymptotic analysis of the near-field focusing property is presented for two dimensions and three dimensions. It is shown that to have a subwavelength focal spot, the TRM should consist of dipole transducers. The transverse resolution of the dipole TRM is linearly proportional to the distance between the point source and the TRM. The mixed mode TRM has the similar (linear) behavior in three dimensions, but in two dimensions the transverse resolution behaves as the square root of the distance between the point source and the TRM. The monopole TRM is ineffective in focusing below the wavelength. Contrary to the matched field processing and the phase processor, both of which resemble TR, TR in a weak- or non-scattering medium is usually biased in the longitudinal direction, especially when TR is carried out on a single plane with a finite aperture. This is true for all five TR schemes. On the other hand, the TR focal spot has been shown repeatedly in the literature, both theoretically and experimentally, to be centered at the source point when the medium is multiple scattering. A reconciliation of the two seemingly conflicting results is found in the random fluctuations in the intensity of the Green function for a multiple scattering medium and the notion of scattering-enlarged effective aperture.

  12. Displacement sensor for indoor machine calibrations.

    PubMed

    Mudassar, Asloob Ahmad; Butt, Saira

    2013-05-20

    This paper presents a simple displacement sensor for indoor machine calibrations. The sensor, which is placed in the path of a diverging laser beam, consists of two plane mirror pieces laterally displaced with the line joining their centers initially held perpendicular to the optical axis of the beam during the displacement of the sensor with one of the mirrors always traveling along the optical axis of the laser beam. The optical signals from the two mirrors are combined and a simple detector at the interference plane counts the fringes during the sensor displacement. The sensor could be mounted on the moving head of any mechanical machine, e.g., the lathe machine for displacement calibration. The device has been tested over a range of 10 cm beyond a distance of 150 cm from a diverging laser source giving an accuracy of 1.1015 μm. Theoretical modeling, simulation, and experimental results are presented which establish that the proposed sensor can be used as a promising displacement measuring device. PMID:23736230

  13. Coated laser mirror and method of coating

    SciTech Connect

    Shuskus, A.J.; Cowher, M.E.

    1984-04-24

    A method of applying an intermediate bond coat on a laser mirror substrate is described comprising surface polishing the mirror substrate followed by depositing a layer of amorphous silicon, amorphous germanium, or mixtures thereof on the mirror surface, and polishing the thus coated mirror surface to a substantially void-free surface finish. Laser mirror substrates such as graphite fiber reinforced glass, molybdenum and silicon carbide coated by such process are also described.

  14. Alignment Mirror Mechanisms for Space Use

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.; McKinney, Colin M.; Smythe, Robert F.; Palmer, Dean

    2011-01-01

    The paper describes an optical Alignment Mirror Mechanism (AMM), and discusses its control scheme. The mirror's angular positioning accuracy requirement is +/- 0.2 arc-sec. This requires the mirror's linear positioning actuators to have a positioning accuracy of +/- 109 nm to enable the mirror to meet the angular tip/tilt accuracy requirement. Demonstrated capabilities are +/- 35 nm linear positioning capability at the actuator, which translates into +/- 0.07 arc-sec angular mirror positioning accuracy.

  15. Lightweight C/SiC mirrors for space application

    NASA Astrophysics Data System (ADS)

    Zhou, Hao; Zhang, Chang-rui; Cao, Ying-bin; Zhou, Xin-gui

    2006-02-01

    Challenges in high resolution space telescopes have led to the desire to create large primary mirror apertures. Ceramic mirrors and complex structures are becoming more important for high precision lightweight optical applications in adverse environments. Carbon-fiber reinforced silicon carbide (C/SiC) has shown great potential to be used as mirror substrate. This material has a high stiffness to weight ratio, dimensional stability from ambient to cryo temperatures, and thermal conductivity, low thermal expansion as well. These properties make C/SiC very attractive for a variety of applications in precision optical structures, especially when considering space-borne application. In this paper, lightweight C/SiC mirror prepared for a scan mirror of a high resolution camera is presented. The manufacturing of C/SiC mirror starts with a porous rigid felt made of short chopped carbon fibers. The fibers are molded with phenolic resin under pressure to form a carbon fiber reinforced plastic blank, followed by a pyrolization process by which the phenolic resin reacts to a carbon matrix. The C/C-felt can be machined by standard computer controlled milling techniques to any virtual shape. This is one of the most significant advantages of this material, as it drastically reduces the making costs and enables the manufacture of truly ultra-lightweight mirrors, reflectors and structures. Upon completion of milling, the C/C-felt preform is mounted in a high-temperature furnace together with silicon and heated under vacuum condition to 1500°C at which the silicon changes into liquid phase. Subsequently, the molten silicon is infiltrated into the porous preform under capillary forces to react with carbon matrix and the surfaces of the carbon fibers to form a density C/SiC substrate. The C/SiC material retains the preform shape to within a tight tolerance after sintering means the ceramization process is a nearly net shaping process. Reactive melt infiltrated C/SiC, followed by

  16. TEMPO machine

    SciTech Connect

    Rohwein, G.J.; Lancaster, K.T.; Lawson, R.N.

    1986-06-01

    TEMPO is a transformer powered megavolt pulse generator with an output pulse of 100 ns duration. The machine was designed for burst mode operation at pulse repetition rates up to 10 Hz with minimum pulse-to-pulse voltage variations. To meet the requirement for pulse duration a nd a 20-..omega.. output impedance within reasonable size constraints, the pulse forming transmission line was designed as two parallel water-insulated, strip-type Blumleins. Stray capacitance and electric fields along the edges of the line elements were controlled by lining the tank with plastic sheet.

  17. Electrical machine

    DOEpatents

    De Bock, Hendrik Pieter Jacobus; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Gerstler, William Dwight; Shah, Manoj Ramprasad; Shen, Xiaochun

    2016-06-21

    An apparatus, such as an electrical machine, is provided. The apparatus can include a rotor defining a rotor bore and a conduit disposed in and extending axially along the rotor bore. The conduit can have an annular conduit body defining a plurality of orifices disposed axially along the conduit and extending through the conduit body. The rotor can have an inner wall that at least partially defines the rotor bore. The orifices can extend through the conduit body along respective orifice directions, and the rotor and conduit can be configured to provide a line of sight along the orifice direction from the respective orifices to the inner wall.

  18. Scalable stacked array piezoelectric deformable mirror for astronomy and laser processing applications

    SciTech Connect

    Wlodarczyk, Krystian L. Maier, Robert R. J.; Hand, Duncan P.; Bryce, Emma; Hutson, David; Kirk, Katherine; Schwartz, Noah; Atkinson, David; Beard, Steven; Baillie, Tom; Parr-Burman, Phil; Strachan, Mel

    2014-02-15

    A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

  19. Focusing mirror for x-ray free-electron lasers

    SciTech Connect

    Mimura, Hidekazu; Kimura, Takashi; Yamakawa, Daisuke; Matsuyama, Satoshi; Morita, Shinya; Uehara, Yoshihiro; Ohmori, Hitoshi; Lin, Weimin; Yumoto, Hirokatsu; Ohashi, Haruhiko

    2008-08-15

    We present the design, fabrication, and evaluation of a large total-reflection mirror for focusing x-ray free-electron laser beams to nanometer dimensions. We used an elliptical focusing mirror made of silicon that was 400 mm long and had a focal length of 550 mm. Electrolytic in-process dressing grinding was used for initial-step figuring and elastic emission machining was employed for final figuring and surface smoothing. A figure accuracy with a peak-to-valley height of 2 nm was achieved across the entire area. Characterization of the focused beam was performed at BL29XUL of SPring-8. The focused beam size was 75 nm at 15 keV, which is almost equal to the theoretical size.

  20. Position sensors for segmented mirror

    NASA Astrophysics Data System (ADS)

    Rozière, Didier; Buous, Sébastien; Courteville, Alain

    2004-09-01

    There are currently several projects for giant telescopes with segmented mirrors under way. These future telescopes will have their primary mirror made of several thousand segments. The main advantage of segmentation is that it enables the active control of the whole mirror, so as to suppress the deformations of the support structure due to the wind, gravity, thermal inhomogeneities etc. ..., thus getting the best possible stigmatism. However, providing active control of segmented mirrors requires numerous accurate edges sensors. It is acknowledged that capacitance-based technology nowadays offers the best metrological performances-to-cost ratio. As the leader in capacitive technology, FOGALE nanotech offers an original concept which reduces the cost of instrumentation, sensors and electronics, while keeping a very high level of performances with a manufacturing process completely industrialised. We present here the sensors developed for the Segment Alignment Measurement System (SAMS) of the Southern African Large Telescope (SALT). This patented solution represents an important improvement in terms of cost, to market the Position Sensors for Segmented Mirrors of ELTs, whilst maintaining a very high performance level. We present here the concept, the laboratory qualification, and the first trials on the 7 central segments of SALT. The laboratory results are good, and we are now working on the on-site implementation to improve the immunity of the sensors to environment.

  1. Gasdynamic Multiple-Mirror Trap

    NASA Astrophysics Data System (ADS)

    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.

  2. Tunneling machine

    SciTech Connect

    Snyder, L.L.

    1980-02-19

    A diametrically compact tunneling machine for boring tunnels is disclosed. The machine includes a tubular support frame having a hollow piston mounted therein which is movable from a retracted position in the support frame to an extended position. A drive shaft is rotatably mounted in the hollow piston and carries a cutter head at one end. The hollow piston is restrained against rotational movement relative to the support frame and the drive shaft is constrained against longitudinal movement relative to the hollow piston. A plurality of radially extendible feet project from the support frame to the tunnel wall to grip the tunnel wall during a tunneling operation wherein the hollow piston is driven forwardly so that the cutter head works on the tunnel face. When the hollow piston is fully extended, a plurality of extendible support feet, which are fixed to the rearward and forward ends of the hollow piston, are extended, the radially extendible feet are retracted and the support frame is shifted forwardly by the piston so that a further tunneling operation may be initiated.

  3. Compact neutron imaging system using axisymmetric mirrors

    SciTech Connect

    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.

  4. Parallel machines: Parallel machine languages

    SciTech Connect

    Iannucci, R.A. )

    1990-01-01

    This book presents a framework for understanding the tradeoffs between the conventional view and the dataflow view with the objective of discovering the critical hardware structures which must be present in any scalable, general-purpose parallel computer to effectively tolerate latency and synchronization costs. The author presents an approach to scalable general purpose parallel computation. Linguistic Concerns, Compiling Issues, Intermediate Language Issues, and hardware/technological constraints are presented as a combined approach to architectural Develoement. This book presents the notion of a parallel machine language.

  5. Metrology of IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  6. Development of Individually Addressable Micro-Mirror-Arrays for Space Applications

    NASA Technical Reports Server (NTRS)

    Dutta, Sanghamitra B.; Ewin, Audrey J.; Jhabvala, Murzy; Kotecki, Carl A.; Kuhn, Jonathan L.; Mott, D. Brent

    2000-01-01

    We have been developing a 32 x 32 prototype array of individually addressable Micro-Mirrors capable of operating at cryogenic temperature for Earth and Space Science applications. Micro-Mirror-Array technology has the potential to revolutionize imaging and spectroscopy systems for NASA's missions of the 21st century. They can be used as programmable slits for the Next Generation Space Telescope, as smart sensors for a steerable spectrometer, as neutral density filters for bright scene attenuation etc. The, entire fabrication process is carried out in the Detector Development Laboratory at NASA, GSFC. The fabrication process is low temperature compatible and involves integration of conventional CMOS technology and surface micro-machining used in MEMS. Aluminum is used as the mirror material and is built on a silicon substrate containing the CMOS address circuit. The mirrors are 100 microns x l00 microns in area and deflect by +/- 10 deg induced by electrostatic actuation between two parallel plate capacitors. A pair of thin aluminum torsion straps allow the mirrors to tilt. Finite-element-analysis and closed form solutions using electrostatic and mechanical torque for mirror operation were developed and the results were compared with laboratory performance. The results agree well both at room temperature and at cryogenic temperature. The development demonstrates the first cryogenic operation of two-dimensional Micro-Mirrors with bi-state operation. Larger arrays will be developed meeting requirements for different science applications. Theoretical analysis, fabrication process, laboratory test results and different science applications will be described in detail.

  7. Minimizing high spatial frequency residual error in active space telescope mirrors

    NASA Astrophysics Data System (ADS)

    Gray, Thomas L.; Smith, Matthew W.; Cohan, Lucy E.; Miller, David W.

    2009-08-01

    The trend in future space telescopes is towards larger apertures, which provide increased sensitivity and improved angular resolution. Lightweight, segmented, rib-stiffened, actively controlled primary mirrors are an enabling technology, permitting large aperture telescopes to meet the mass and volume restrictions imposed by launch vehicles. Such mirrors, however, are limited in the extent to which their discrete surface-parallel electrostrictive actuators can command global prescription changes. Inevitably some amount of high spatial frequency residual error is added to the wavefront due to the discrete nature of the actuators. A parameterized finite element mirror model is used to simulate this phenomenon and determine designs that mitigate high spatial frequency residual errors in the mirror surface figure. Two predominant residual components are considered: dimpling induced by embedded actuators and print-through induced by facesheet polishing. A gradient descent algorithm is combined with the parameterized mirror model to allow rapid trade space navigation and optimization of the mirror design, yielding advanced design heuristics formulated in terms of minimum machinable rib thickness. These relationships produce mirrors that satisfy manufacturing constraints and minimize uncorrectable high spatial frequency error.

  8. Fokker-Planck equation in mirror research

    SciTech Connect

    Post, R.F.

    1983-08-11

    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.

  9. Fused silica mirror development for SIRTF

    NASA Technical Reports Server (NTRS)

    Barnes, W. P., Jr.

    1983-01-01

    An advanced design, lightweight, fuse-quartz mirror of sandwich construction was evaluated for optical figure performance at cryogenic temperatures. A low temperature shroud was constructed with an integral mirror mount and interface to a cryostat for use in a vacuum chamber. The mirror was tested to 13 K. Cryogenic distortion of the mirror was measured interferometrically. Separate interferometry of the chamber window during the test permitted subtraction of the small window distortions from the data. Results indicate that the imaging performance of helium cooled, infrared telescopes will be improved using this type of mirror without correction of cryogenic distortion of the primary mirror.

  10. First Giant Mirror for the ESO VLT Ready at REOSC

    NASA Astrophysics Data System (ADS)

    1995-11-01

    The REOSC Contract In 1989, the European Southern Observatory (ESO), the European Organisation for Astronomy, awarded to REOSC, a subsidiary of the SFIM Group and located in Saint Pierre du Perray (France), a comprehensive contract for the polishing of four 8.2-metre diameter mirrors for the unit telescopes of the ESO Very Large Telescope (VLT) project. These mirrors are the largest ever manufactured and polished. This contract comprises not only the polishing and high-precision optical testing of each giant mirror, but also the safe condition of transportation of the blanks which were manufactured by Schott Glaswerke in Mainz (Germany). In order to fulfill the contract, REOSC conceived, built and equipped a novel, high-tech workshop which would allow to polish and test the mirrors, each of which has a surface area of more than 50 square metres. First 8.2-Metre Mirror is Ready and within Specifications The REOSC polishing facility for giant mirrors was built in Saint Pierre du Perray, just south of Paris. It is equipped with two machines: one for grinding and the other for polishing the mirrors, and both with 150-actuator systems that support the thin and flexible mirrors. All equipment is computer controlled. State-of-the-art interferometers probe the accuracy of the mirror surface as the polishing proceeds; they are installed at the top level of the facility in a 30-metre high tower, at the centre of the mirror's radius of curvature. The success of the work at REOSC is now evident by the fact that careful measurements of the first mirror earlier this month have shown that the final optical surface is correct to within 0.00005 millimetres. For illustration, this corresponds to an accuracy of only 1 millimetre deviation over a surface with a diameter of 165 kilometres (equivalent to the entire Paris area)! ESO Receives the First VLT Mirror After having been carefully placed in a special transport box designed by REOSC, the first mirror blank, weighing 23.5 tons and

  11. High temperature current mirror amplifier

    DOEpatents

    Patterson, R.B. III.

    1984-05-22

    Disclosed is a high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg. 2 figs.

  12. Microwave Tomography Using Deformable Mirrors

    NASA Astrophysics Data System (ADS)

    Arunachalam, Kavitha; Udpa, Lalita; Udpa, Satish S.

    2008-09-01

    Microwave tomography aims to reconstruct the spatial distribution of the electrical property of penetrable objects using field measurements acquired from multiple views at single or multiple frequencies. This paper presents a novel microwave tomography technique to image penetrable scatterers using deformable mirrors. The deformable mirror consists of a continuum of radiating elements that yields multi-view field measurements for noninvasive characterization of the spatial dielectric property of the scatterer in the microwave regime. Computational feasibility of the proposed technique is presented for heterogeneous two dimensional dielectric scatterers.

  13. Silicon cladding for mirror substrates

    NASA Astrophysics Data System (ADS)

    Duston, Christopher J.; Gunda, Nilesh; Schwartz, Jay R.; Robichaud, Joseph L.

    2009-08-01

    To reduce the finishing costs of silicon carbide mirror substrates, silicon claddings are applied allowing the surfaces to be more easily diamond turned and polished than the bare chemical vapor deposited (CVD) silicon carbide or bimodal reaction bonded SiC (RB-SiC). The benefits of using silicon as the optical face will be reviewed as will the process for applying plasma enhanced chemical vapor (PE-CVD) deposited amorphous silicon cladding on substrates. Using one mirror as an example, the successful finishing results will be shared.

  14. Controllable objective with deformable mirrors

    SciTech Connect

    Agafonov, V V; Safronov, A G

    2004-03-31

    A new optical device - an objective with deformable mirrors and parameters controlled in the dynamic regime is proposed. The computer simulation of the objective is performed. The dependences of some parameters of the objective on the control voltage are determined. The simulation showed that the ranges of control of the rear focal segment and the focal distance for the objective with the focal distance 602 mm were 1057 and 340 mm, respectively, which is substantially greater than in the control of an equivalent deformable mirror. (laser applications and other topics in quantum electronics)

  15. Compaction managed mirror bend achromat

    DOEpatents

    Douglas, David

    2005-10-18

    A method for controlling the momentum compaction in a beam of charged particles. The method includes a compaction-managed mirror bend achromat (CMMBA) that provides a beamline design that retains the large momentum acceptance of a conventional mirror bend achromat. The CMMBA also provides the ability to tailor the system momentum compaction spectrum as desired for specific applications. The CMMBA enables magnetostatic management of the longitudinal phase space in Energy Recovery Linacs (ERLs) thereby alleviating the need for harmonic linearization of the RF waveform.

  16. Strength of Zerodur® for mirror applications

    NASA Astrophysics Data System (ADS)

    Béhar-Lafenêtre, S.; Cornillon, Laurence; Ait-Zaid, Sonia

    2015-09-01

    Zerodur® is a well-known glass-ceramic used for optical components because of its unequalled dimensional stability under thermal environment. In particular it has been used since decades in Thales Alenia Space's optical payloads for space telescopes, especially for mirrors. The drawback of Zerodur® is however its quite low strength, but the relatively small size of mirrors in the past had made it unnecessary to further investigate this aspect, although elementary tests have always shown higher failure strength. As performance of space telescopes is increasing, the size of mirrors increases accordingly, and an optimization of the design is necessary, mainly for mass saving. Therefore the question of the effective strength of Zerodur® has become a real issue. Thales Alenia Space has investigated the application of the Weibull law and associated size effects on Zerodur® in 2014, under CNES funding, through a thorough test campaign with a high number of samples (300) of various types. The purpose was to accurately determine the parameters of the Weibull law for Zerodur® when machined in the same conditions as mirrors. The proposed paper will discuss the obtained results, in the light of the Weibull theory. The applicability of the 2-parameter and 3-parameter (with threshold strength) laws will be compared. The expected size effect has not been evidenced therefore some investigations are led to determine the reasons of this result, from the test implementation quality to the data post-processing methodology. However this test campaign has already provided enough data to safely increase the allowable value for mirrors sizing.

  17. Active feedback stabilization of flute instability in a mirror trap

    NASA Astrophysics Data System (ADS)

    Be'Ery, Ilan; Seemann, Omri; Fruchtman, Amnon; Fisher, Amnon; Ron, Amiram

    2013-10-01

    The flute instability in a table-top mirror machine has been stabilized by a feedback system consisting of optical probes, digital signal processor, and needle electrodes. The total response time of the system is 5 μs, which is considerably faster than the typical flute growth time. Simulation and a dynamic model of the plasma's response to the needle actuators were tested against cyclic bias experiments. The plasma density is increased by the stabilization by a factor of two and is limited by other decay processes.

  18. NASA CONNECT: Algebra: Mirror, Mirror on the Universe

    NASA Technical Reports Server (NTRS)

    2000-01-01

    'Algebra: Mirror, Mirror on the Universe' is the last of seven programs in the 1999-2000 NASA CONNECT series. Produced by NASA Langley Research Center's Office of Education, NASA CONNECT is an award-winning series of instructional programs designed to enhance the teaching of math, science and technology concepts in grades 5-8. NASA CONNECT establishes the 'connection' between the mathematics, science, and technology concepts taught in the classroom and NASA research. Each program in the series supports the national mathematics, science, and technology standards; includes a resource-rich teacher guide; and uses a classroom experiment and web-based activity to complement and enhance the math, science, and technology concepts presented in the program. NASA CONNECT is FREE and the programs in the series are in the public domain. Visit our web site and register. http://connect.larc.nasa.gov In 'Algebra: Mirror, Mirror on the Universe', students will learn how algebra is used to explore the universe.

  19. Tandem Mirror Experiment Upgrade (TMX-U) overview-recent events

    SciTech Connect

    Calderon, M.O.; Bell, H.H.

    1985-11-14

    Since its construction and commissioning was completed in the winter of 1981, the Tandem Mirror Experiment Upgrade (TMX-U) has been conducting tandem mirror thermal barrier experiments. The work, following the fall of 1983 when strong plugging with thermal barriers was achieved, has been directed toward controlling radial transport and forming thermal barriers with high density and Beta. This paper describes the overall engineering component of these efforts. Major changes to the machine have included vacuum improvements, changes to the Electron and Ion Cyclotron Resonance Heating systems (ECRH and ICRH), and the installation of a Plasma Potential Control system (PPC) for radial transport reduction. TMX-U operates an extensive diagnostics system that acquires data from 21 types of diagnostic instruments with more than 600 channels, in addition to 246 machine parameters. The changes and additions will be presented. The closing section of this paper will describe the initial study work for a proposed TMX-U octupole configured machine.

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

    PubMed Central

    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

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

    PubMed

    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. PMID:23709352

  2. Manufacturing of freeform mirror by milling and altering its optical characteristics by Ns-laser polishing and ALD coatings

    NASA Astrophysics Data System (ADS)

    Mutanen, Jarkko; Kaakkunen, Jarno J. J.; Tuovinen, Hemmo; Hiltunen, Jouni; Kivi, Sini; Toiviainen, Maunu; Väyrynen, Juha; Laukkanen, Janne; Prokofiev, Victor; Pääkkönen, Pertti; Juuti, Mikko; Kuittinen, Markku; Mönkkönen, Kari

    2014-09-01

    In this study we tested ns-laser and an atomic layer deposition (ALD) for polishing and coating CNC-machined aluminum freeform mirrors that are used in a compact multipoint fiber optical probe. Two types of ALD coatings, aluminum oxide and silicon dioxide were tested. The surface roughness of mirrors was analyzed prior to and after nanosecond-laser polishing and coating them on a Beneq TFS 200 ALD device. The freeform aluminum mirrors with and without coatings were then measured with optical profiler. The results show that improvement in the surface roughness can be seen with ns-laser polished and ALD coated aluminum surfaces.

  3. Collodion technique of mirror cleaning

    NASA Technical Reports Server (NTRS)

    Tyndall, J. B.

    1970-01-01

    Cleaning method is modified by addition of a layer of cheesecloth between thin coatings of U.S.P. collodion. After drying, the collodion is peeled off by an even pull on the cheesecloth, leaving the mirror clean and ready for use.

  4. RF plugging of mirror plasma

    SciTech Connect

    Kotelnikov, I.A.; Kuzmin, S.G.

    1996-12-01

    Discovery of superconducting materials that operate at high temperatures revives interest in the use of rf field for plasma confinement. This paper discusses feasibility of a scheme where resonant rf cavities are attached to the mirror ends of an open system for plasma confinement. 9 refs., 9 figs.

  5. Mirror Confinement Systems: project summaries

    SciTech Connect

    Not Available

    1980-07-01

    This report contains descriptions of the projects supported by the Mirror Confinement Systems (MCS) Division of the Office of Fusion Energy. The individual project summaries were prepared by the principal investigators, in collaboration with MCS staff office, and include objectives and milestones for each project. In addition to project summaries, statements of Division objectives and budget summaries are also provided.

  6. Microfabricated mirrors for space applications

    NASA Astrophysics Data System (ADS)

    Bayat, Dara; Ataman, Caglar; Guldimann, Benedikt; Lani, Sébastien; Noell, Wilfried; de Rooij, Nico

    2011-03-01

    We report on the advances towards the design and fabrication of a system consisting of two 10mm mirrors, one actuated magnetically and the other electrostatically. The system will be used for beam steering. The maximum resonant frequencies and deflection angle of each of the actuators will be reviewed and compared.

  7. Mirror with thermally controlled radius of curvature

    DOEpatents

    Neil, George R.; Shinn, Michelle D.

    2010-06-22

    A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

  8. Secrets of the Chinese magic mirror replica

    NASA Astrophysics Data System (ADS)

    Mak, Se-yuen; Yip, Din-yan

    2001-03-01

    We examine the structure of five Chinese magic mirror replicas using a special imaging technique developed by the authors. All mirrors are found to have a two-layered structure. The reflecting surface that gives rise to a projected magic pattern on the screen is hidden under a polished half-reflecting top layer. An alternative method of making the magic mirror using ancient technology has been proposed. Finally, we suggest a simple method of reconstructing a mirror replica in the laboratory.

  9. Mounting and Alignment of IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Zhang, William; Evans, Tyler; McClelland, Ryan; Hong, Melinda; Mazzarella, James; Saha, Timo; Jalota, Lalit; Olsen, Lawrence; Byron, Glenn

    2010-01-01

    A suspension-mounting scheme is developed for the IXO (International X-ray Observatory) mirror segments in which the figure of the mirror segment is preserved in each stage of mounting. The mirror, first fixed on a thermally compatible strongback, is subsequently transported, aligned and transferred onto its mirror housing. In this paper, we shall outline the requirement, approaches, and recent progress of the suspension mount processes.

  10. Detecting surface faults on solar mirrors

    NASA Technical Reports Server (NTRS)

    Argoud, M. J.; Shumate, M. S.; Walker, W. L.; Zanteson, R. A.

    1980-01-01

    Two quality control tests determine reflectivity and curvature faults of concave solar mirrors. Curvature defects in solar mirrors are easily revealed by photographing mirror surface. Calibrated aperture placed in front of camera lens admits rays reflecting only from acceptable areas of mirror, blocking out diverging rays reflected from defective areas. Defects can pinpoint problems that may exist in production. Same photograph can be obtained using calibrated disk instead of aperture, except that, this time, only defective areas would be exposed.

  11. The Axisymmetric Tandem Mirror: A Magnetic Mirror Concept Game Changer Magnet Mirror Status Study Group

    SciTech Connect

    Simonen, T; Cohen, R; Correll, D; Fowler, K; Post, D; Berk, H; Horton, W; Hooper, E B; Fisch, N; Hassam, A; Baldwin, D; Pearlstein, D; Logan, G; Turner, B; Moir, R; Molvik, A; Ryutov, D; Ivanov, A A; Kesner, J; Cohen, B; McLean, H; Tamano, T; Tang, X Z; Imai, T

    2008-10-24

    Experimental results, theory and innovative ideas now point with increased confidence to the possibility of a Gas Dynamic Trap (GDT) neutron source which would be on the path to an attractively simple Axisymmetric Tandem Mirror (ATM) power plant. Although magnetic mirror research was terminated in the US 20 years ago, experiments continued in Japan (Gamma 10) and Russia (GDT), with a very small US effort. This research has now yielded data, increased understanding, and generated ideas resulting in the new concepts described here. Early mirror research was carried out with circular axisymmetric magnets. These plasmas were MHD unstable due to the unfavorable magnetic curvature near the mid-plane. Then the minimum-B concept emerged in which the field line curvature was everywhere favorable and the plasma was situated in a MHD stable magnetic well (70% average beta in 2XII-B). The Ioffe-bar or baseball-coil became the standard for over 40 years. In the 1980's, driven by success with minimum-B stabilization and the control of ion cyclotron instabilities in PR6 and 2XII-B, mirrors were viewed as a potentially attractive concept with near-term advantages as a lower Q neutron source for applications such as a hybrid fission fuel factory or toxic waste burner. However there are down sides to the minimum-B geometry: coil construction is complex; restraining magnetic forces limit field strength and mirror ratios. Furthermore, the magnetic field lines have geodesic curvature which introduces resonant and neoclassical radial transport as observed in early tandem mirror experiments. So what now leads us to think that simple axisymmetric mirror plasmas can be stable? The Russian GDT experiment achieves on-axis 60% beta by peaking of the kinetic plasma pressure near the mirror throat (where the curvature is favorable) to counter-balance the average unfavorable mid-plane curvature. Then a modest augmentation of plasma pressure in the expander results in stability. The GDT

  12. Machine musicianship

    NASA Astrophysics Data System (ADS)

    Rowe, Robert

    2002-05-01

    The training of musicians begins by teaching basic musical concepts, a collection of knowledge commonly known as musicianship. Computer programs designed to implement musical skills (e.g., to make sense of what they hear, perform music expressively, or compose convincing pieces) can similarly benefit from access to a fundamental level of musicianship. Recent research in music cognition, artificial intelligence, and music theory has produced a repertoire of techniques that can make the behavior of computer programs more musical. Many of these were presented in a recently published book/CD-ROM entitled Machine Musicianship. For use in interactive music systems, we are interested in those which are fast enough to run in real time and that need only make reference to the material as it appears in sequence. This talk will review several applications that are able to identify the tonal center of musical material during performance. Beyond this specific task, the design of real-time algorithmic listening through the concurrent operation of several connected analyzers is examined. The presentation includes discussion of a library of C++ objects that can be combined to perform interactive listening and a demonstration of their capability.

  13. Machine wanting.

    PubMed

    McShea, Daniel W

    2013-12-01

    Wants, preferences, and cares are physical things or events, not ideas or propositions, and therefore no chain of pure logic can conclude with a want, preference, or care. It follows that no pure-logic machine will ever want, prefer, or care. And its behavior will never be driven in the way that deliberate human behavior is driven, in other words, it will not be motivated or goal directed. Therefore, if we want to simulate human-style interactions with the world, we will need to first understand the physical structure of goal-directed systems. I argue that all such systems share a common nested structure, consisting of a smaller entity that moves within and is driven by a larger field that contains it. In such systems, the smaller contained entity is directed by the field, but also moves to some degree independently of it, allowing the entity to deviate and return, to show the plasticity and persistence that is characteristic of goal direction. If all this is right, then human want-driven behavior probably involves a behavior-generating mechanism that is contained within a neural field of some kind. In principle, for goal directedness generally, the containment can be virtual, raising the possibility that want-driven behavior could be simulated in standard computational systems. But there are also reasons to believe that goal-direction works better when containment is also physical, suggesting that a new kind of hardware may be necessary. PMID:23792091

  14. 21 CFR 886.1500 - Headband mirror.

    Code of Federal Regulations, 2010 CFR

    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...

  15. 21 CFR 886.1500 - Headband mirror.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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...

  16. Light Weight Silicon Mirrors for Space Instrumentation

    NASA Technical Reports Server (NTRS)

    Bly, Vincent T.; Hill, Peter C.; Hagopian, John G.; Strojay, Carl R.; Miller, Timothy

    2012-01-01

    Each mirror is a monolithic structure from a single crystal of silicon. The mirrors are light weighted after the optical surface is ground and polished. Mirrors made during the initial phase of this work were typically 1/50 lambda or better (RMS at 633 n m)

  17. Tandem mirror next step conceptual design

    SciTech Connect

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

    1980-10-14

    A study was made to define the features of the experimental mirror fusion device - The Tandem Mirror Next Step, or TMNS - that will bridge the gap between present mirror confinement experiments and a power-producing reactor. We outline the project goals, describe some initial device parameters, and relate the technological requirements to ongoing development programs.

  18. Simulation analysis of position error of parabolic trough concentrator mirror installation

    NASA Astrophysics Data System (ADS)

    Tian, Guo-liang; Yan, Bi-xi; Dong, Mingli; Wang, Jun; Sun, Peng

    2015-02-01

    The research showed the simulation of position error when assembling a reflective mirror of parabolic trough concentrator. The shape of a reflective mirror is like a parabolic cylinder model, relying on the back of the four-point mounted on a special setup, making it unable to move. Therefore, it is of great importance of the machining precision of special bracket. We need to analyze the influence of reflective mirror`s intercept factor in order to guide the processing precision. It is assumed that each reflective mirror is rigid, we have calculated the intercept factor of reflector with mounting points' random error of different standard deviation, comparing the simulating results with TRACEPRO. As a sequence, we can approve the feasibility of the algorithm, and give the effect of different random errors on the light-gathering efficiency. On the basis, we provide the machining accuracy of bracket. The simulation results show that when the mounting points' standard deviation of position error is less than 0.5 mm, the intercept factor of receiver has reached upwards of 92% with 60 mm diameter for receiver, which can satisfy the design requirements.

  19. Optimization of the process chain for mirrors made of silicon carbide

    NASA Astrophysics Data System (ADS)

    Waechter, Daniel; Kroedel, Matthias; Huenten, Martin; Klocke, Fritz

    2012-09-01

    Different grades of silicon carbide (SiC) became an established material for structures as well as optical mirrors in space-borne applications. But the manufacturing still causes high efforts and restrains an extension of application in further fields. The research project MirrorFab aims for a qualification of an optimized process chain for manufacturing mirrors made of Cesic®. Cesic® consists of a matrix of SiC reinforced with chopped carbon fibers. There is a space qualified Cesic® manufacturing process and an established network for the supply chain. The project addresses the required gain in efficiency and flexibility in the manufacturing capabilities. The consortium covers the major parts of the process chain. It aims for increasing the performance of each manufacturing technology. Additionally, the consideration of the complete process chain enables a holistic optimization approach. This paper deals particularly with the process optimization of the grinding step after infiltration. The benefit of the use of an ultra precision grinding machine for mirrors in the range of 200 mm is evaluated. This paper presents the results of a systematical study on the influence of the grit size, the type of bond as well the major machining parameters on the surface roughness and the grinding forces, when machining the material Cesic®. A major finding is, that the use of ultra fine grinding wheels does not result in a superior surface quality compared to the use of a D46 grinding wheel with resinoid bond.

  20. Material removal characteristics of orthogonal velocity polishing tool for efficient fabrication of CVD SiC mirror surfaces

    NASA Astrophysics Data System (ADS)

    Seo, Hyunju; Han, Jeong-Yeol; Kim, Sug-Whan; Seong, Sehyun; Yoon, Siyoung; Lee, Kyungmook; Lee, Haengbok

    2015-09-01

    Today, CVD SiC mirrors are readily available in the market. However, it is well known to the community that the key surface fabrication processes and, in particular, the material removal characteristics of the CVD SiC mirror surface varies sensitively depending on the shop floor polishing and figuring variables. We investigated the material removal characteristics of CVD SiC mirror surfaces using a new and patented polishing tool called orthogonal velocity tool (OVT) that employs two orthogonal velocity fields generated simultaneously during polishing and figuring machine runs. We built an in-house OVT machine and its operating principle allows for generation of pseudo Gaussian shapes of material removal from the target surface. The shapes are very similar to the tool influence functions (TIFs) of other polishing machine such as IRP series polishing machines from Zeeko. Using two CVD SiC mirrors of 150 mm in diameter and flat surface, we ran trial material removal experiments over the machine run parameter ranges from 12.901 to 25.867 psi in pressure, 0.086 m/sec to 0.147 m/sec in tool linear velocity, and 5 to 15 sec in dwell time. An in-house developed data analysis program was used to obtain a number of Gaussian shaped TIFs and the resulting material removal coefficient varies from 3.35 to 9.46 um/psi hour m/sec with the mean value to 5.90 ± 1.26(standard deviation). We report the technical details of the new OVT machine, of the data analysis program, of the experiments and the results together with the implications to the future development of the OVT machine and process for large CVD SiC mirror surfaces.

  1. Development of Coherent X-ray Diffraction Apparatus with Kirkpatrick-Baez Mirror Optics

    SciTech Connect

    Takahashi, Y.; Tsutsumi, R.; Mimura, H.; Matsuyama, S.; Nishino, Y.; Ishikawa, T.; Yamauchi, K.

    2011-09-09

    To realize coherent x-ray diffraction microscopy with higher spatial resolution, it is necessary to increase the density of x-ray photons illuminated onto the sample. In this study, we developed a coherent x-ray diffraction apparatus with Kirkpatrick-Baez mirror optics. By using mirrors fabricated by elastic emission machining, a high-density coherent x-ray beam was produced. In a demonstration experiment using a silver nanocube as a sample, a high-contrast coherent x-ray diffraction pattern was observed over a wide-q range. This proves that both the density and the degree of coherence of the focused beam were high.

  2. TRL-6 Qualification of JWST Mirror Segments

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2009-01-01

    Since 1996, all key mirror technology for a JWST Primary Mirror Segment Assembly (PMSA), as defined directly from the JWST Level 1 Science Requirements, have been developed and matured from a Technology Readiness Level (TRL) of 3 to 6. This has occurred as the result of a highly successful technology development program including sub-scale Beryllium Mirror Demonstrator (SBMD), Advanced Mirror System Demonstrator (AMSD), and JWST flight mirror fabrication. Directly traceable prototypes (and in some cases the flight hardware itself) has been built, tested and operated in a relevant environment.

  3. The VST secondary mirror support system

    NASA Astrophysics Data System (ADS)

    Schipani, P.; Perrotta, F.; Molfese, C.; Caputi, O.; Ferragina, L.; Marty, L.; Capaccioli, M.; Gallieni, D.; Fumi, P.; Anaclerio, E.; Lazzarini, P.; De Paris, G.

    2008-07-01

    The VST telescope is equipped with an active optics system based on a wavefront sensor, a set of axial actuators to change the primary mirror shape and a secondary mirror positioner stage. The secondary mirror positioning capability allows the correction of defocus and coma optical aberrations, mainly caused by incorrect relative positions of the optics. The secondary mirror positioner is a 6-6 Stewart platform (also called "hexapod"). It is a parallel robot with a mobile platform moved by 6 linear actuators acting simultaneously. This paper describes the secondary mirror support system and the current status of the work.

  4. First Results of the Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.

    2002-01-01

    An experimental Gasdynamic Mirror or GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the applicability of this technology for propulsion systems. This paper presents the first experimental results obtained from the machine and an analysis of the types of plasma instabilities likely to be encountered. It is intended that this device operate at higher plasma densities and with much larger L/D ratios than previous mirror machines. The high L/D ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. The high plasma density results in the plasma behaving much more like a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. The device has been constructed to allow a considerable degree of flexibility in its configuration thus permitting the experiment to grow over time without necessitating a great deal of additional fabrication.

  5. JWST Lightweight Mirror TRL-6 Results

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2007-01-01

    Mirror technology for a Primary Mirror Segment Assembly (PMSA) is a system of components: reflective coating; polished optical surface; mirror substrate; actuators, mechanisms and flexures; and reaction structure. The functional purpose of a PMSA is to survive launch, deploy and align itself to form a 25 square meter collecting area 6.5 meter diameter primary mirror with a 131 nm rms wavefront error at temperatures less than 50K and provide stable optical performance for the anticipated thermal environment. At the inception of JWST in 1996, such a capability was at a Technology Readiness Level (TRL) of 3. A highly successful technology development program was initiated including the Sub-scale Beryllium Mirror Demonstrator (SBMD) and Advanced Mirror System Demonstrator (AMSD) projects. These projects along with flight program activities have matured mirror technology for JWST to TRL-6. A directly traceable prototype (and in some cases the flight hardware itself) has been built, tested and operated in a relevant environment.

  6. Constellation-X mirror technology development

    NASA Astrophysics Data System (ADS)

    Zhang, W. W.; Bolognese, J.; Byron, G.; Chang, K. W.; Content, D. A.; Hadjimichael, T. J.; He, Charles; Hill, M. D.; Hong, M.; Lehan, J. P.; Lozipone, L.; Mazzarella, J. M.; McClelland, R.; Nguyen, D. T.; Olsen, L.; Petre, R.; Robinson, D.; Rohrbach, S. O.; Russell, R.; Saha, T. T.; Sharpe, M.; Gubarev, M. V.; Jones, W. D.; O'Dell, S. L.; Davis, W.; Caldwell, D. R.; Freeman, M.; Podgorski, W.; Reid, P. B.

    2008-07-01

    As NASA's next major space X-ray observatory, the Constellation-X mission (Bookbinder et al. 2008) requires mirror assemblies with unprecedented characteristics that cannot be provided by existing optical technologies. In the past several years, the project has supported a vigorous mirror technology development program. This program includes the fabrication of lightweight mirror segments by slumping commercially available thin glass sheets, the support and mounting of these thin mirror segments for accurate metrology, the mounting and attachment of these mirror segments for the purpose of X-ray tests, and development of methods for aligning and integrating these mirror segments into mirror assemblies. This paper describes our efforts and developments in these areas.

  7. Design of a rapidly cooled cryogenic mirror

    NASA Astrophysics Data System (ADS)

    Plummer, Ron; Hsu, Ike

    1993-01-01

    The paper discusses the design, analysis, and testing of a rapidly cooled beryllium cryogenic mirror, which is the primary mirror in the four-element optical system for the Long Wavelength Infrared Advanced Technology Seeker. The mirror is shown to meet the requirement of five minutes for cooling to cryogenic operating temperature; it also maintains its optical figure and vacuum integrity and meets the nuclear specification. Results of a detailed thermal analysis on the mirror showed that, using nitrogen gas at 80 K as coolant, the front face of the mirror can be cooled from an initial temperature of 300 K to less than 90 K within five minutes. In a vacuum chamber, using liquid nitrogen as coolant, the mirror can be cooled to 80 K within 1.5 min. The mirror is well thermally insulated, so that it can be maintained at less than its operating temperature for a long time without active cooling.

  8. A Deployable Primary Mirror for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Phelps, James E.; Dyer, Jack E.; Caudle, David A.; Tam, Anthony; Escobedo, Javier; Kasl, Eldon P.

    1999-01-01

    NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (light direction and ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55-m-diameter, proof-of-concept mirror.

  9. Radius of curvature controlled mirror

    DOEpatents

    Neil, George R.; Rathke, John Wickham; Schultheiss, Thomas John; Shinn, Michelle D.; Dillon-Townes, Lawrence A.

    2006-01-17

    A controlled radius of curvature mirror assembly comprising: a distortable mirror having a reflective surface and a rear surface; and in descending order from the rear surface; a counter-distortion plate; a flow diverter having a flow diverter aperture at the center thereof; a flow return plate having a flow return aperture at the center thereof; a thermal isolation plate having a thermal isolation plate aperture at the center thereof and a flexible heater having a rear surface and a flexible heater aperture at the center thereof; a double walled tube defining a coolant feed chamber and a coolant return chamber; said coolant feed chamber extending to and through the flow diverter aperture and terminating at the counter-distortion plate and the coolant return chamber extending to and through the thermal isolation backplate and terminating at the flow diverter; and a coolant feed and a coolant return exit at the rear of said flexible heater.

  10. Oculometer focus and mirror control

    NASA Technical Reports Server (NTRS)

    Guy, W. J.

    1982-01-01

    An automatic focusing system designed around an ultrasonic range measurement is described. Besides maintaining the focus, subject distance is a by-product which could lighten the NOVA computational effort. An automatic head tracking unit is also discussed. It is intended to reduce the search time required when track is lost. An X-Y ultrasonic measurement is also made in this design to control the deflection mirrors.

  11. Afocal correctors for paraboloidal mirrors.

    PubMed

    Wynne, C G

    1967-07-01

    A new form of field corrector for astronomical telescopes with paraboloidal primary mirrors is described. It consists of four separated spherical surfaced lenses and gives improved aberration correction. The method of designing is described, and the adaptability of the design to telescopes of different characteristics is discussed. Numerical data and details of performance are given for a specific design for the Palomar Observatory 200-in. (5.08-m) telescope. PMID:20062169

  12. Nine toes; Mirror Foot Deformity

    PubMed Central

    Vlahovic, Aleksandar M; Pistignjat, Boris S; Vlahovic, Natasa S

    2015-01-01

    Mirror foot is a very rare congenital anomaly, with only a few papers presenting definitive treatment for this entity. There are limited management recommendations. Most cases are treated before walking age. In our case, there were no associated developmental defects of the leg. The child underwent complex rays resection with medial foot reconstruction. After 7.5 years of followup, definitive surgical treatment was performed with satisfactory cosmetic and functional outcome. PMID:26229172

  13. Development of the Large Scanning Mirror Using Fe-Based Metallic Glass Ribbon

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Wung; Lin, Yu-Ching; Chen, Na; Louzguine, D. V.; Esashi, Masayoshi; Gessner, Thomas

    2011-08-01

    In order to achieve the large scanning angle without mechanical failure during actuation, the micro-mirror structure was fabricated using Fe-based metallic glass (MG) ribbon. High values of mechanical strength and elastic strain limit are desired for the torsion bar for providing high performance of the mirror, including large tilting angle and good stability. MG materials guarantee superior value of elastic strain limit and fracture toughness resulting from its amorphous structure without line defects like dislocations and grain boundaries. We chose Fe-base MG material for mirror actuation according to its good soft magnetic properties and simple structure without any further step of integration of magnetic material. Millimeter-size mirror device was successfully fabricated by laser machining techniques from Fe-based MG ribbon. Extremely large optical tilting angle of exceeding 100° was obtained on activation of the mirror by magnetic force when electrical current of 100 mA was applied. Large tilting angle of the mirror is due to the torsion bar which was fabricated with Fe-based MG material that has large elastic strain limit and high fracture toughness.

  14. Fabrication and metrology of freeform aluminum mirrors for the SCUBA-2 instrument

    NASA Astrophysics Data System (ADS)

    Saunders, Ian J.; Ploeg, Leo; Dorrepaal, Michiel; van Venrooij, Bart

    2005-09-01

    TNO Science and Industry was contracted by the UK Astronomy Technology Center to deliver nine aluminum freeform mirrors for a new sub-millimeter instrument called SCUBA-2. With a much larger field-of-view and sky-background limited sensitivity, SCUBA-2 will map large areas of sky up to 1000 times faster than the original SCUBA camera. The requirement for freeform optics on SCUBA-2 is due to the fact that conventional spherical optic systems do not fit into the allotted space. TNO, who has developed a number of enabling technologies for freeform fabrication and metrology, applied its skills to the mechanical design and analysis of the mirrors. Due to the diverging requirements of the nine mirrors in size, form, and accuracy, TNO needed to spread the fabrication and metrology over additional organizations. The National Aerospace Laboratory of the Netherlands machined and hand polished the five largest mirrors (dimensions exceeding 1 meter and mass exceeding 150kg). They obtained form accuracies between 10 and 15μm peak to valley and roughness down to 40nm RMS. TNO fabricated the smaller and more accurate mirrors (dimensions between 300 and 700mm) on a Precitech Nanoform 350 with a slow tool servo. Measurements by the Dutch National Metrology Institute indicated form accuracies between 4 and 6μm peak to valley and roughness below 20nm RMS for the smaller mirrors.

  15. MODEL SIMULATIONS OF CONTINUOUS ION INTERJECTION INTO EBIS TRAP WITH SLANTED ELECTROSTATIC MIRROR.

    SciTech Connect

    PIKIN,A.; KPONOU, A.; ALESSI, J.G.; BEEBE, E.N.; PRELEC, K.; RAPARIA, D.

    2007-08-26

    The efficiency of trapping ions in an EBIS is of primary importance for many applications requiring operations with externally produced ions: RIA breeders, ion sources, traps. At the present time, the most popular method of ion injection is pulsed injection, when short bunches of ions get trapped in a longitudinal trap while traversing the trap region. Continuous trapping is a challenge for EBIS devices because mechanisms which reduce the longitudinal ion energy per charge in a trap (cooling with residual gas, energy exchange with other ions, ionization) are not very effective, and accumulation of ions is slow. A possible approach to increase trapping efficiency is to slant the mirror at the end of the trap which is opposite to the injection end. A slanted mirror will convert longitudinal motion of ions into transverse motion, and, by reducing their longitudinal velocity, prevent these ions from escaping the trap on their way out. The trade off for the increased trapping efficiency this way is an increase in the initial transverse energy of the accumulated ions. The slanted mirror can be realized if the ends of two adjacent electrodes- drift tubes - which act as an electrostatic mirror, are machined to produce a slanted gap, rather than an upright one. Applying different voltages to these electrodes will produce a slanted mirror. The results are presented of 2D and 3D computer simulations of ion injection into a simplified model of EBIS with slanted mirror.

  16. Cost-optimized methods extending the solution space of lightweight spaceborne monolithic ZERODUR® mirrors to larger sizes

    NASA Astrophysics Data System (ADS)

    Leys, Antoine; Hull, Tony; Westerhoff, Thomas

    2015-09-01

    We address the problem that larger spaceborne mirrors require greater sectional thickness to achieve a sufficient first eigen frequency that is resilient to launch loads, and to be stable during optical telescope assembly integration and test, this added thickness results in unacceptable added mass if we simply scale up solutions for smaller mirrors. Special features, like cathedral ribs, arch, chamfers, and back-side following the contour of the mirror face have been considered for these studies. For computational efficiency, we have conducted detailed analysis on various configurations of a 800 mm hexagonal segment and of a 1.2-m mirror, in a manner that they can be constrained by manufacturing parameters as would be a 4-m mirror. Furthermore each model considered also has been constrained by cost-effective machining practice as defined in the SCHOTT Mainz factory. Analysis on variants of this 1.2-m mirror has shown a favorable configuration. We have then scaled this optimal configuration to 4-m aperture. We discuss resulting parameters of costoptimized 4-m mirrors. We also discuss the advantages and disadvantages this analysis reveals of going to cathedral rib architecture on 1-m class mirror substrates.

  17. Construction of Prototype Lightweight Mirrors

    NASA Technical Reports Server (NTRS)

    Robinson, William G.

    1997-01-01

    This contract and the work described was in support of a Seven Segment Demonstrator (SSD) and demonstration of a different technology for construction of lightweight mirrors. The objectives of the SSD were to demonstrate functionality and performance of a seven segment prototype array of hexagonal mirrors and supporting electromechanical components which address design issues critical to space optics deployed in large space based telescopes for astronomy and for optics used in spaced based optical communications systems. The SSD was intended to demonstrate technologies which can support the following capabilities; Transportation in dense packaging to existing launcher payload envelopes, then deployable on orbit to form space telescope with large aperture. Provide very large (less than 10 meters) primary reflectors of low mass and cost. Demonstrate the capability to form a segmented primary or quaternary mirror into a quasi-continuous surface with individual subapertures phased so that near diffraction limited imaging in the visible wavelength region is achieved. Continuous compensation of optical wavefront due to perturbations caused by imperfections, natural disturbances, and equipment induced vibrations/deflections to provide near diffraction limited imaging performance in the visible wavelength region. Demonstrate the feasibility of fabricating such systems with reduced mass and cost compared to past approaches. While the SSD could not be expected to satisfy all of the above capabilities, the intent was to start identifying and understanding new technologies that might be applicable to these goals.

  18. Deflectometric measurement of large mirrors

    NASA Astrophysics Data System (ADS)

    Olesch, Evelyn; Häusler, Gerd; Wörnlein, André; Stinzing, Friedrich; van Eldik, Christopher

    2014-06-01

    We discuss the inspection of large-sized, spherical mirror tiles by `Phase Measuring Deflectometry' (PMD). About 10 000 of such mirror tiles, each satisfying strict requirements regarding the spatial extent of the point-spread-function (PSF), are planned to be installed on the Cherenkov Telescope Array (CTA), a future ground-based instrument to observe the sky in very high energy gamma-rays. Owing to their large radii of curvature of up to 60 m, a direct PSF measurement of these mirrors with concentric geometry requires large space. We present a PMD sensor with a footprint of only 5×2×1.2 m3 that overcomes this limitation. The sensor intrinsically acquires the surface slope; the shape data are calculated by integration. In this way, the PSF can be calculated for real case scenarios, e.g., when the light source is close to infinity and off-axis. The major challenge is the calibration of the PMD sensor, specifically because the PSF data have to be reconstructed from different camera views. The calibration of the setup is described, and measurements presented and compared to results obtained with the direct approach.

  19. Applied machine vision

    SciTech Connect

    Not Available

    1984-01-01

    This book presents the papers given at a conference on robot vision. Topics considered at the conference included the link between fixed and flexible automation, general applications of machine vision, the development of a specification for a machine vision system, machine vision technology, machine vision non-contact gaging, and vision in electronics manufacturing.

  20. Machine Shop Lathes.

    ERIC Educational Resources Information Center

    Dunn, James

    This guide, the second in a series of five machine shop curriculum manuals, was designed for use in machine shop courses in Oklahoma. The purpose of the manual is to equip students with basic knowledge and skills that will enable them to enter the machine trade at the machine-operator level. The curriculum is designed so that it can be used in…

  1. Mirror Metrology Using Nano-Probe Supports

    NASA Technical Reports Server (NTRS)

    Robinson, David; Hong, Maoling; Byron, Glenn; McClelland, Ryan; Chan, Kai-Wing

    2012-01-01

    Thin, lightweight mirrors are needed for future x-ray space telescopes in order to increase x-ray collecting area while maintaining a reduced mass and volume capable of being launched on existing rockets. However, it is very difficult to determine the undistorted shape of such thin mirrors because the mounting of the mirror during measurement causes distortion. Traditional kinematic mounts have insufficient supports to control the distortion to measurable levels and prevent the mirror from vibrating during measurement. Over-constrained mounts (non-kinematic) result in an unknown force state causing mirror distortion that cannot be determined or analytically removed. In order to measure flexible mirrors, it is necessary to over-constrain the mirror. Over-constraint causes unknown distortions to be applied to the mirror. Even if a kinematic constraint system can be used, necessary imperfections in the kinematic assumption can lead to an unknown force state capable of distorting the mirror. Previously, thicker, stiffer, and heavier mirrors were used to achieve low optical figure distortion. These mirrors could be measured to an acceptable level of precision using traditional kinematic mounts. As lighter weight precision optics have developed, systems such as the whiffle tree or hydraulic supports have been used to provide additional mounting supports while maintaining the kinematic assumption. The purpose of this invention is to over-constrain a mirror for optical measurement without causing unacceptable or unknown distortions. The invention uses force gauges capable of measuring 1/10,000 of a Newton attached to nano-actuators to support a thin x-ray optic with known and controlled forces to allow for figure measurement and knowledge of the undeformed mirror figure. The mirror is hung from strings such that it is minimally distorted and in a known force state. However, the hanging mirror cannot be measured because it is both swinging and vibrating. In order to

  2. Manufacturing Large Membrane Mirrors at Low Cost

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Relatively inexpensive processes have been developed for manufacturing lightweight, wide-aperture mirrors that consist mainly of reflectively coated, edge-supported polyimide membranes. The polyimide and other materials in these mirrors can withstand the environment of outer space, and the mirrors have other characteristics that make them attractive for use on Earth as well as in outer space: With respect to the smoothness of their surfaces and the accuracy with which they retain their shapes, these mirrors approach the optical quality of heavier, more expensive conventional mirrors. Unlike conventional mirrors, these mirrors can be stowed compactly and later deployed to their full sizes. In typical cases, deployment would be effected by inflation. Potential terrestrial and outer-space applications for these mirrors include large astronomical telescopes, solar concentrators for generating electric power and thermal power, and microwave reflectors for communication, radar, and short-distance transmission of electric power. The relatively low cost of manufacturing these mirrors stems, in part, from the use of inexpensive tooling. Unlike in the manufacture of conventional mirrors, there is no need for mandrels or molds that have highly precise surface figures and highly polished surfaces. The surface smoothness is an inherent property of a polyimide film. The shaped area of the film is never placed in contact with a mold or mandrel surface: Instead the shape of a mirror is determined by a combination of (1) the shape of a fixture that holds the film around its edge and (2) control of manufacturing- process parameters. In a demonstration of this manufacturing concept, spherical mirrors having aperture diameters of 0.5 and 1.0 m were fabricated from polyimide films having thicknesses ranging from <20 m to 150 m. These mirrors have been found to maintain their preformed shapes following deployment.

  3. Manufacture of fly-eye mirror in an extreme-ultraviolet lithography illumination system by means of ultraprecision diamond cutting

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yoshinori; Takeuchi, Yoshimi; Kawai, Tomohiko; Sawada, Kiyoshi; Takino, Hideo; Shibata, Norio

    2002-07-01

    This study deals with the manufacture of so-called Fly-eye mirror in EUV lithography by means of an ultraprecision 5-axis control milling technology. It is extremely difficult to manufacture a highly accurate Fly-eye mirror by conventional methods such as photolithography, mechanical cutting by a lathe, etc. since it is composed of 500 circular arc mirror elements of 15 mm in length and 1 mm in width having a spherical surface of 295 mm in radius, and there are minute steps among them. In order to manufacture Fly-eye mirror with accuracy and efficiency, the study proposes a new machining method to manufacture spherical surface with any radius by employing a rotational single-crystal diamond tool with cutting edge angle of 90 degree. Oxygen-free copper was machined by this method. The machined workpiece shows smooth spherical surface and sharp steps among them without any burrs. It is found that the proposed method has the potential of producing the Fly-eye mirror.

  4. Assessment of cleaning methods for first mirrors tested in JET for ITER

    NASA Astrophysics Data System (ADS)

    Ivanova, D.; Widdowson, A.; Likonen, J.; Marot, L.; Koivuranta, S.; Coad, J. P.; Rubel, M.; Petersson, P.; De Temmerman, G.; JET-EFDA Contributors

    2013-07-01

    Two cleaning techniques were used for removal of co-deposits from the tested first mirrors exposed in JET: (a) ultrasonic bath; (b) a broad range of polishing conditions from manual buffing to machine polishing with the diamond grain size of up to 3 μm. Reflectivity measurements were performed after each step in the cleaning procedure. Surfaces were also examined with electron microscopy and ion beam analysis methods. Ultrasonic cleaning leads to partial recovery of reflectivity due to enhanced detachment of deposits. Typically 30-50% of the original reflectivity was recovered in the visible light and 50-90% in the infrared region. One mirror was cleaned completely. Polishing with diamond paste may lead to successful removal of deposits but the damage to the surface in case of the large diamond grains was observed. Recovery of up to 100% of the initial reflectivity was achieved for some mirrors.

  5. Marking LANDSAT images with small mirror reflectors. [in Virginia and California

    NASA Technical Reports Server (NTRS)

    Evans, W. E.

    1975-01-01

    Uniquely identifiable artificial landmarks were generated in LANDSAT imagery by making use of specular solar reflection from small, easily transportable mirrors. The results are impressive in well-registered color composite enlargements, where the mirror returns appear as bright white spots. The signatures are unique enough that returns can be readily located in the computer compatible tape records either manually or by machine search. As embodied in experiments to date, the system is entirely passive. Mirrors must be carefully positioned prior to each satellite pass, but the required angle calculations are simple enough to be made on a hand calculator and the required input data are easily available. Possible applications of the technique include providing site identification and geodetic control in remote regions of the earth, enhancement of small targets such as offshore oil derricks, providing atmospheric transmission data coincident with other LANDSAT experiments, and providing a nearly perfect optical point source for overall system checkout.

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

    PubMed

    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. PMID:21889132

  7. Magnetic mirror fusion: status and prospects

    SciTech Connect

    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.

  8. Novel unimorph adaptive mirrors for astronomy applications

    NASA Astrophysics Data System (ADS)

    Rausch, Peter; Verpoort, Sven; Wittrock, Ulrich

    2012-07-01

    We have developed a new type of unimorph deformable mirror for the correction of low-order Zernike modes. The mirror features a clear aperture of 50 mm combined with large peak-to-valley amplitudes of up to 35 μm. Newly developed fabrication processes allow the use of prefabricated, coated, super-polished glass substrates. The mirror's unique features suggest the use in several astronomical applications like the compensation of atmospheric aberrations seen by laser beacons and the use in woofer-tweeter systems. Additionally, the design enables an efficient correction of the inevitable wave-front error imposed by the floppy structure of primary mirrors in future large space telescopes. We have modeled the mirror by using analytical as well as finite element models. We will present design, key features and manufacturing steps of the deformable mirror.

  9. Passivation coating for flexible substrate mirrors

    DOEpatents

    Tracy, C. Edwin; Benson, David K.

    1990-01-01

    A protective diffusion barrier for metalized mirror structures is provided by a layer or coating of silicon nitride which is a very dense, transparent, dielectric material that is impervious to water, alkali, and other impurities and corrosive substances that typically attack the metal layers of mirrors and cause degradation of the mirrors' reflectivity. The silicon nitride layer can be deposited on the substrate before metal deposition thereon to stabilize the metal/substrate interface, and it can be deposited over the metal to encapsulate it and protect the metal from corrosion or other degradation. Mirrors coated with silicon nitride according to this invention can also be used as front surface mirrors. Also, the silver or other reflective metal layer on mirrors comprising thin, lightweight, flexible substrates of metal or polymer sheets coated with glassy layers can be protected with silicon nitride according to this invention.

  10. Vacuum measurements on the Tandem Mirror Experiment Upgrade (TMX-U) fusion experiment

    SciTech Connect

    Hunt, A.L.; Lang, D.D.; Nexsen, W.E.; Pickles, W.L.; Turner, W.C.

    1984-09-01

    The gas inventory of the Tandem Mirror Experiment Upgrade (TMX-U) must be carefully controlled, if it is to successfully create various plasma configurations for thermal barrier experiments designed to provide an improved performance for tandem mirror experiments. This paper is a progress report on the calibration methods and pressure measurements of machine conditions deriving from recently improved neutral-beam gas control, and changes to the internal baffling geometry and the gettering system. Various recorded pressure vs time histories produced by the machine's internal vacuum systems and their pumping mechanisms are presented. An upgraded computer code for calculating dynamic pressures is described. Our concluding remarks deal with the problems of establishing and maintaining a pressure measuring system for a large fusion experiment, where the quality and reliability of components must be carefully considered.

  11. Tandem mirror technology demonstration facility

    SciTech Connect

    Not Available

    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.

  12. Deformable Mirrors Correct Optical Distortions

    NASA Technical Reports Server (NTRS)

    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.

  13. Process for preparing improved silvered glass mirrors

    DOEpatents

    Buckwalter, Jr., Charles Q.

    1981-01-01

    Glass mirrors having improved weathering properties are prepared by an improvement in the process for making the mirrors. The glass surface after it has been cleaned but before it is silvered, is contacted with a solution of lanthanide rare earths in addition to a sensitization solution of tin or palladium. The addition of the rare earths produces a mirror which has increased resistance to delamination of the silver from the glass surface in the presence of water.

  14. Process for preparing improved silvered glass mirrors

    DOEpatents

    Buckwalter, C.Q. Jr.

    1980-01-28

    Glass mirrors having improved weathering properties are prepared by an improvement in the process for making the mirrors. The glass surface after it has been cleaned but before it is silvered, is contacted with a solution of lanthanide rare earths in addition to a sensitization solution of tin or palladium. The addition of the rare earths produces a mirror which has increased resistance to delamination of the silver from the glass surface in the presence of water.

  15. Integrated dual-stage deformable mirrors

    NASA Astrophysics Data System (ADS)

    Griffith, Mike; Laycock, Leslie; Archer, Nick; Myers, Richard; Kirby, Andrew; Doel, Peter; Brooks, David

    2010-07-01

    We present the results of a study on Dual-Stage Deformable Mirrors using Zonal Bimorph Deformable Mirror (ZBDM) technology. A high density 'tweeter' DM has been assembled onto a lower density, high dynamic range 'woofer' DM to generate an integrated mirror which offers both high resolution and dynamic range simultaneously. Such a device has the potential to significantly simplify the design of astronomical Adaptive Optics (AO) systems. The latest developments are presented, including the fabrication of a small scale demonstrator.

  16. Fabricating the LSST Mirrors: A Progress Report

    NASA Astrophysics Data System (ADS)

    Sebag, Jacques; Gressler, W.; Neill, D.; Hileman, E.; LSST Collaboration

    2009-01-01

    The LSST uses a modified Paul-Baker 3-mirror optical design with 8.4-m primary, 3.4-m secondary and 5-m tertiary mirrors feeding a 3 element refractive corrector to produce a 3.5-degree diameter field of view over a 64-cm flat focal surface in 6 spectral bands with excellent image quality. The proximity of the primary and tertiary surfaces enables fabrication of both mirrors from a single substrate. This unique design, referred to as the M1M3 monolith, offers significant advantages in the reduction of degrees of freedom during operational alignment and improved structural stiffness for the otherwise annular primary surface. The convex secondary will be the largest of its kind. As with all large optical elements, both of the LSST mirrors have long procurement times. In order to meet the LSST's first light schedule for the fall of 2014 we have started the fabrication process on both mirrors using private funding. The M1M3 monolith is being fabricated at the Steward Observatory Mirror Lab using their structured borosilicate spin casting technology. The M1M3 was successfully cast over the summer of 2008. The mold refractory cleanout process and detailed inspections are underway in preparation for back side processing. The casting includes special design features to enable the mirror to operate under the increased loads caused by the high accelerations needed by the LSST. The secondary mirror substrate is being made using Corning's Ultra Low Expansion (ULE) process, resulting in an annular meniscus mirror 100mm thick and a 1.8m diameter central hole. Glass selection for the secondary mirror has begun and the substrate will be fused late in 2008. Both mirrors are on schedule and their early start has substantially reduced risk within the LSST project. Topics: LSST Optics Mirrors

  17. Advanced Mirror System Demonstrator (AMSD) Risk Management

    NASA Technical Reports Server (NTRS)

    Byberg, Alicia; Russell, J. Kevin; Kaukler, Donna; Burdine, Robert V. (Technical Monitor)

    2002-01-01

    This paper will report risk issues associated with designing, manufacturing, and testing the Advanced Mirror System Demonstrator (AMSD). The Advanced Mirror System Demonstrator (AMSD) will be developed as a lightweight primary mirror system that can be produced at a low cost and with a short manufacturing schedule. This technology will add to the knowledge base for selection for the Next Generation Space Telescope (NGST), Space Based Laser (SBL), Research Laboratory mission (AFRL), and other government agency programs.

  18. Deformable mirror for short wavelength applications

    DOEpatents

    Chapman, Henry N.; Sweeney, Donald W.

    1999-01-01

    A deformable mirror compatible with short wavelength (extreme ultraviolet) radiation that can be precisely controlled to nanometer and subnanometer accuracy is described. Actuators are coupled between a reaction plate and a face plate which has a reflective coating. A control system adjusts the voltage supplied to the actuators; by coordinating the voltages supplied to the actuators, the reflective surface of the mirror can be deformed to correct for dimensional errors in the mirror or to produce a desired contour.

  19. Membrane Mirrors With Bimorph Shape Actuators

    NASA Technical Reports Server (NTRS)

    Yang, Eui-Hyeok

    2003-01-01

    Deformable mirrors of a proposed type would be equipped with relatively-large-stroke microscopic piezoelectric actuators that would be used to maintain their reflective surfaces in precise shapes. These mirrors would be members of the class of MEMS-DM (for microelectromechanical system deformable mirror) devices, which offer potential for a precise optical control in adaptive-optics applications in such diverse fields as astronomy and vision science. The proposed mirror would be fabricated, in part, by use of a membrane-transfer technique. The actuator design would contain bimorph-type piezoelectric actuators.

  20. ZERODUR for lightweight secondary/tertiary mirrors

    NASA Astrophysics Data System (ADS)

    Morian, Hans F.; Mackh, Reiner

    1998-08-01

    ZERODUR, the glass ceramic, with CTE values near zero, has excellent performance up to 8.2 m primary mirrors as well as for lightweight (LW) mirrors for Secondaries and Tertiaries. The high homogeneity of major properties of ZERODUR is an important prerequisite for the LW production and application. The production of CNC grinding and subsequent lightening via acid etching for additional weight reduction will be discussed. Results of Secondary and Tertiary LW mirrors for advanced technology telescopes like 8 m, 6.5 m and 3.5 m telescopes will be addressed. This paper presents also some examples of space based satellites with LW Zerodur mirrors in use since several years.

  1. Are mirror-sensations really synesthetic?

    PubMed

    Derbyshire, Stuart W G

    2015-01-01

    Mirror-sensations, including touch and pain, are often referred to as synesthetic. The term can be challenged, however, because mirror-sensations lack the incongruency and saliency of synesthesia, may involve problems of perspective rather than entangled sensations, and may be easier to generate with suggestion. If mirror-sensations are truly sensations then they might be expected to act like the true sensation and mirror-pain, for example, might inhibit pain at a distance or itch in the same location. These predictions are highly testable. PMID:25997924

  2. Topology optimization design of a space mirror

    NASA Astrophysics Data System (ADS)

    Liu, Jiazhen; Jiang, Bo

    2015-11-01

    As key components of the optical system of the space optical remote sensor, Space mirrors' surface accuracy had a direct impact that couldn't be ignored of the imaging quality of the remote sensor. In the future, large-diameter mirror would become an important trend in the development of space optical technology. However, a sharp increase in the mirror diameter would cause the deformation of the mirror and increase the thermal deformation caused by temperature variations. A reasonable lightweight structure designed to ensure the optical performance of the system to meet the requirements was required. As a new type of lightweight approach, topology optimization technology was an important direction of the current space optical remote sensing technology research. The lightweight design of rectangular mirror was studied. the variable density method of topology optimization was used. The mirror type precision of the mirror assemblies was obtained in different conditions. PV value was less than λ/10 and RMS value was less than λ/50(λ = 632.8nm). The results show that the entire The mirror assemblies can achieve a sufficiently high static rigidity, dynamic stiffness and thermal stability and has the capability of sufficient resistance to external environmental interference . Key words: topology optimization, space mirror, lightweight, space optical remote sensor

  3. First mirrors for diagnostic systems of ITER

    NASA Astrophysics Data System (ADS)

    Litnovsky, A.; Voitsenya, V. S.; Costley, A.; Donné, A. J. H.; SWG on First Mirrors of the ITPA Topical Group on Diagnostics

    2007-08-01

    The majority of optical diagnostics presently foreseen for ITER will implement in-vessel metallic mirrors as plasma-viewing components. Mirrors are used for the observation of the plasma radiation in a very wide wavelength range: from about 1 nm up to a few mm. In the hostile ITER environment, mirrors are subject to erosion, deposition, particle implantation and other adverse effects which will change their optical properties, affecting the entire performance of the respective diagnostic systems. The Specialists Working Group (SWG) on first mirrors was established under the wings of the International Tokamak Physics Activity (ITPA) Topical Group (TG) on Diagnostics to coordinate and guide the investigations on diagnostic mirrors towards the development of optimal, robust and durable solutions for ITER diagnostic systems. The results of tests of various ITER-candidate mirror materials, performed in Tore-Supra, TEXTOR, DIII-D, TCV, T-10, TRIAM-1M and LHD under various plasma conditions, as well as an overview of laboratory investigations of mirror performance and mirror cleaning techniques are presented in the paper. The current tasks in the R&D of diagnostic mirrors will be addressed.

  4. Double curvature mirrors for linear concentrators

    NASA Astrophysics Data System (ADS)

    Lance, Tamir; Ackler, Harold; Finot, Marc

    2012-10-01

    Skyline Solar's medium concentration photovoltaic system uses quasi-parabolic mirrors and one axis tracking. Improvements in levelized cost of energy can be achieved by effective management of non-uniformity of the flux line on the panels. To reduce non uniformity of the flux line due to mirror to mirror gaps, Skyline developed a dual curvature mirror that stretches the flux line along the panel. Extensive modeling and experiments have been conducted to analyze the impact of this new design and to optimize the design.

  5. Isospin symmetry in mirror α decays

    NASA Astrophysics Data System (ADS)

    Timofeyuk, N. K.; Descouvemont, P.; Johnson, R. C.

    2007-03-01

    We show that a consequence of isospin symmetry, recently discovered in mirror conjugated one-nucleon decays, can be extended to mirror-conjugated α-particle decays, both virtual and real. For virtual α decays of bound mirror pairs this symmetry manifests itself as a relation between the asymptotic normalization coefficients (ANCs) of α-particle overlap integrals. This relation is given by a simple analytical formula that involves α-particle separation energies and charges of residual nuclei. For bound-unbound mirror pairs, the ANC of a bound nucleus is related to the α width of the mirror unbound level. For unbound mirror pairs we get a new analytical formula that relates the widths of mirror resonances. We test the validity of these analytical formulas against the predictions of a two-body potential and of a many-body microscopic cluster model for several mirror states in Li7-Be7, B11-C11, and F19-Ne19 isotopes. We show that these analytical formulas are valid in many cases but that some deviations can be expected for isotopes with strongly deformed and easily excited cores. In general, the results from microscopic model are not very sensitive to model assumptions and can be used to predict unknown astrophysically relevant cross sections using known information about mirror systems.

  6. Astronomical Secondary Mirrors And Field Correctors: Special Challenges And Metrology Solutions Routinely Used At Brashear

    NASA Astrophysics Data System (ADS)

    Piche, Francios; Gardopee, G.; Clarkson, A.; Hull, T.

    2012-01-01

    It has been said that the secondary mirror is the most difficult optic of an astronomical telescope. Much of this difficulty is associated with metrology of a convex mirror. With the advent of highly deterministic modern optical finishing machines delivering high process convergence rates, like those processes used at L-3 Integrated Optical Systems (IOS), the availability of high-quality metrology on convex optical surfaces is of greater importance to take full advantage of those new technological capabilities. Once the surface error map is determined, modern optical finishing machines, like those at L-3 Integrated Optical Systems (IOS), can readily make the correction, even on optics mounted in their deliverable cells. Due to IOS' innovative engineering coupled with our extensive experience with large, fast secondary mirrors, we have delivered exceptional mirrors on short schedules. We frequently address requirements where the optical figure must be controlled to a few nanometers in wavefront error, and associated metrology must address not only low spatial frequencies (LSF), but also mid spatial frequencies (MSF) and high spatial frequencies (HSF). Special tooling and techniques that control the accumulated error are described, and examples of control of all spatial frequencies presented. Methods are available at IOS to remove predicted mounting dimples whether measured in-situ with the optics mounted in its cell or predicted from a finite-element model of the mounted optic. We will also describe metrology methods for astronomical field correctors.

  7. Fabrication of experimental three-meter space telescope primary and secondary mirror support structure

    NASA Technical Reports Server (NTRS)

    Mishler, H. W.

    1974-01-01

    The fabrication of prototype titanium alloy primary and secondary mirror support structures for a proposed experimental three-meter space telescope is discussed. The structure was fabricated entirely of Ti-6Al-4V tubing and plate. Fabrication included the development of procedures including welding, forming, and machining. Most of the structures was fabricated by gas-shielding tungsten-arc (GTA) welding with several major components fabricated by high frequency resistance (HFR) welding.

  8. The uncanny mirror: a re-framing of mirror self-experience.

    PubMed

    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. PMID:20889353

  9. Hard Machinable Machining of Cobalt Super Alloys

    NASA Astrophysics Data System (ADS)

    Čep, Robert; Janásek, Adam; Petrů, Jana; Čepová, Lenka; Sadílek, Marek; Kratochvíl, Jiří

    2012-12-01

    The article deals with difficult-to-machine cobalt super alloys. The main aim is to test the basic properties of cobalt super alloys and propose suitable cutting materials and machining parameters under the designation 188 when machining. Although the development of technology in chipless machining such as moulding, precision casting and other manufacturing methods continues to advance, machining is still the leading choice for piece production, typical for energy and chemical engineering. Nowadays, super alloys are commonly used in turbine engines in regions that are subject to high temperatures, which require high strength, high temperature resistance, phase stability, as well as corrosion or oxidation resistance.

  10. Interference in multilayer relativistic mirrors

    NASA Astrophysics Data System (ADS)

    Mirzanejhad, Saeed; Sohbatzadeh, Farshad; Babaei, Javad; Taghipour, Meisam; Mohammadzadeh, Zahra

    2015-10-01

    In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, τ p ≫ ( 2 γ 0 ) 5 / 2 / ω p 0 , where τp is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.

  11. Shape memory composite deformable mirrors

    NASA Astrophysics Data System (ADS)

    Riva, M.; Bettini, P.; Di Landro, L.; Sala, G.

    2009-03-01

    This paper deals with some of the critical aspects regarding Shape Memory Composite (SMC) design: firstly some technological aspects concerning embedding technique and their efficiency secondarily the lack of useful numerical tools for this peculiar design. It has been taken into account as a possible application a deformable panel which is devoted to act as a substrate for a deformable mirror. The activity has been mainly focused to the study of embedding technologies, activation and authority. In detail it will be presented the "how to" manufacturing of some smart panels with embedded NiTiNol wires in order to show the technology developed for SMC structures. The first part of the work compares non conventional pull-out tests on wires embedded in composites laminates (real condition of application), with standard pull-out in pure epoxy resin blocks. Considering the numerical approach some different modeling techniques to be implemented in commercial codes (ABAQUS) have been investigated. The Turner's thermo-mechanical model has been adopted for the modeling of the benchmark: A spherical panel devoted to work as an active substrate for a Carbon Fiber Reinforced Plastic (CFRP) deformable mirror has been considered as a significant technological demonstrator and possible future application (f=240mm, r.o.c.=1996mm).

  12. Explaining mirror-touch synesthesia.

    PubMed

    Ward, Jamie; Banissy, Michael J

    2015-01-01

    Mirror-touch synesthesia (MTS) is the conscious experience of tactile sensations induced by seeing someone else touched. This paper considers two different, although not mutually exclusive, theoretical explanations and, in the final section, considers the relation between MTS and other forms of synesthesia and also other kinds of vicarious perception (e.g., contagious yawning). The Threshold Theory explains MTS in terms of hyper-activity within a mirror system for touch and/or pain. This offers a good account for some of the evidence (e.g., from fMRI) but fails to explain the whole pattern (e.g., structural brain differences outside of this system; performance on some tests of social cognition). The Self-Other Theory explains MTS in terms of disturbances in the ability to distinguish the self from others. This can be construed in terms of over-extension of the bodily self in to others, or as difficulties in the control of body-based self-other representations. In this account, MTS is a symptom of a broader cognitive profile. We suggest this meets the criteria for synesthesia, despite the proximal causal mechanisms remaining largely unknown, and that the tendency to localize vicarious sensory experiences distinguishes it from other kinds of seemingly related phenomena (e.g., non-localized affective responses to observing pain). PMID:25893437

  13. Relativistic Tennis Using Flying Mirror

    SciTech Connect

    Pirozhkov, A. S.; Kando, M.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Kimura, T.; Kato, Y.; Tajima, T.; Esirkepov, T. Zh.; Bulanov, S. V.

    2008-06-24

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic 'flying mirror', which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of {approx_equal}4-6x10{sup 19} cm{sup -3}. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are {approx}55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3x10{sup 7} photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  14. ROSAT wide field camera mirrors.

    PubMed

    Willingale, R

    1988-04-15

    The ROSAT wide field camera (WFC) is an XUV telescope operating in the 12-250-eV energy band. The mirror system utilizes Wolter-Schwarzschild type I (WS I) grazing incidence optics with a focal length of 525 mm, comprised of three nested aluminum shells with an outermost diameter of 576 mm providing a geometric aperture area of 456 cm(2). The reflecting surfaces are electroless nickel plated and coated with gold to enhance their reflectivity in the XUV. The mirrors have undergone full aperture optical testing, narrow beam XUV testing, and full aperture XUV testing. Measurements of the reflectivity are compared to theoretical values derived from the optical constants of gold in the XUV range. Analysis of the focused distribution is used to estimate the surface roughness and figuring errors of the polished surfaces. The results are compared to the mechanical metrology data collected during manufacture of the shells and the power spectral density of the reflecting surfaces is found to have a power-law form. PMID:20531591

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

    ERIC Educational Resources Information Center

    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…

  16. James Webb Space Telescope (JWST) Primary Mirror Material Selection

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Feinberg, Lee D.; Russell, Kevin; Texter, Scott

    2004-01-01

    The James Webb Space Telescope (JWST) conducted a phase down select process via the Advanced Mirror System Demonstrator (AMSD) project to assess the Technology Readiness Level of various candidate mirror materials. This process culminated in the selection of Beryllium as the JWST primary mirror material. This paper outlines the mirror evaluation process, defines the selection criteria and summarizes the candidate mirror's performances.

  17. Plasma confinement apparatus using solenoidal and mirror coils

    DOEpatents

    Fowler, T. Kenneth; Condit, William C.

    1979-01-01

    A plasma confinement apparatus, 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.

  18. Tube Alinement for Machining

    NASA Technical Reports Server (NTRS)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  19. Women, Men, and Machines.

    ERIC Educational Resources Information Center

    Form, William; McMillen, David Byron

    1983-01-01

    Data from the first national study of technological change show that proportionately more women than men operate machines, are more exposed to machines that have alienating effects, and suffer more from the negative effects of technological change. (Author/SSH)

  20. Stirling machine operating experience

    NASA Technical Reports Server (NTRS)

    Ross, Brad; Dudenhoefer, James E.

    1991-01-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that Stirling machines are capable of reliable and lengthy lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and were not expected to operate for any lengthy period of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered.

  1. Production of the 4.26 m ZERODUR mirror blank for the Advanced Technology Solar telescope (ATST)

    NASA Astrophysics Data System (ADS)

    Jedamzik, Ralf; Werner, Thomas; Westerhoff, Thomas

    2014-07-01

    The Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST) will be the most powerful solar telescope in the world. It is currently being built by the Association of Universities for Research in Astronomy (AURA) in a height of 3000 m above sea level on the mountain Haleakala of Maui, Hawaii. The primary mirror blank of diameter 4.26 m is made of the extremely low thermal expansion glass ceramic ZERODUR® of SCHOTT AG Advanced Optics. The DKIST primary mirror design is extremely challenging. With a mirror thickness of only 78 to 85 mm it is the smallest thickness ever machined on a mirror of 4.26 m in diameter. Additionally the glassy ZERODUR® casting is one of the largest in size ever produced for a 4 m class ZERODUR® mirror blank. The off axis aspherical mirror surface required sophisticated grinding procedures to achieve the specified geometrical tolerance. The small thickness of about 80 mm required special measures during processing, lifting and transport. Additionally acid etch treatment was applied to the convex back-surface and the conical shaped outer diameter surface to improve the strength of the blank. This paper reports on the challenging tasks and the achievements on the material property and dimensional specification parameter during the production of the 4.26 m ZERODUR® primary mirror blank for AURA.

  2. Machining of beryllium with the LLNL Precision Engineering Research Lathe

    SciTech Connect

    Foley, R.J.

    1985-04-01

    In August 1984, six flat samples of beryllium, which were prepared by Brush-Wellmen Corp. using various pressing and sintering processes, were machined at LLNL on the recently completed Precision Engineering Research Lathe (PERL). The purpose of this study, which was conducted in cooperation with the Hughes Aircraft Corporation and partially funded by that organization, was to determine the optical properties of machined beryllium surfaces when prepared under highly controlled conditions using high quality machine tools and CBN (cubic boron nitrite) cutting tools. This report will summarize the materials properties, the machining conditions used on the PERL and a comparison of the completed samples using optical measuring techniques and scanning electron microscopy (SEM). The mirror surface reflecting measurements in the IR region are to be made by the group at Hughes Aircraft and will be exchanged with LLNL as a part of this joint technical effort. 3 refs., 14 figs.

  3. Automatic Inspection During Machining

    NASA Technical Reports Server (NTRS)

    Ransom, Clyde L.

    1988-01-01

    In experimental manufacturing process, numerically-controlled machine tool temporarily converts into inspection machine by installing electronic touch probes and specially-developed numerical-control software. Software drives probes in paths to and on newly machined parts and collects data on dimensions of parts.

  4. Machining lead wafers

    SciTech Connect

    Schamaun, R.T.

    1987-09-01

    Recently, MEC-6 machined some 4-inch-diameter lead wafers to precision tolerances. The tolerance on the wafer thickness was +-0.000080 inch. A diamond tool was used to machine the wafers on a Moore No. 3 lathe. This report discusses the methods used to machine the wafers, the fixtures used to hold the wafers, and the inspection methods and results.

  5. Apprentice Machine Theory Outline.

    ERIC Educational Resources Information Center

    Connecticut State Dept. of Education, Hartford. Div. of Vocational-Technical Schools.

    This volume contains outlines for 16 courses in machine theory that are designed for machine tool apprentices. Addressed in the individual course outlines are the following topics: basic concepts; lathes; milling machines; drills, saws, and shapers; heat treatment and metallurgy; grinders; quality control; hydraulics and pneumatics;…

  6. Manufacturing Precise, Lightweight Paraboloidal Mirrors

    NASA Technical Reports Server (NTRS)

    Hermann, Frederick Thomas

    2006-01-01

    A process for fabricating a precise, diffraction- limited, ultra-lightweight, composite- material (matrix/fiber) paraboloidal telescope mirror has been devised. Unlike the traditional process of fabrication of heavier glass-based mirrors, this process involves a minimum of manual steps and subjective judgment. Instead, this process involves objectively controllable, repeatable steps; hence, this process is better suited for mass production. Other processes that have been investigated for fabrication of precise composite-material lightweight mirrors have resulted in print-through of fiber patterns onto reflecting surfaces, and have not provided adequate structural support for maintenance of stable, diffraction-limited surface figures. In contrast, this process does not result in print-through of the fiber pattern onto the reflecting surface and does provide a lightweight, rigid structure capable of maintaining a diffraction-limited surface figure in the face of changing temperature, humidity, and air pressure. The process consists mainly of the following steps: 1. A precise glass mandrel is fabricated by conventional optical grinding and polishing. 2. The mandrel is coated with a release agent and covered with layers of a carbon- fiber composite material. 3. The outer surface of the outer layer of the carbon-fiber composite material is coated with a surfactant chosen to provide for the proper flow of an epoxy resin to be applied subsequently. 4. The mandrel as thus covered is mounted on a temperature-controlled spin table. 5. The table is heated to a suitable temperature and spun at a suitable speed as the epoxy resin is poured onto the coated carbon-fiber composite material. 6. The surface figure of the optic is monitored and adjusted by use of traditional Ronchi, Focault, and interferometric optical measurement techniques while the speed of rotation and the temperature are adjusted to obtain the desired figure. The proper selection of surfactant, speed or rotation

  7. Figure and Dimension Metrology of Extremely Lightweight X-Ray Mirrors for Space Astronomy Applications

    NASA Technical Reports Server (NTRS)

    Zhang, William W.

    2010-01-01

    The International X-ray Observatory (IXO) is the next major space X-ray observatory, performing both imaging and spectroscopic studies of all kinds of objects in the Universe. It is a collaborative mission of the National Aeronautics and Space Administration of the United States, the European Space Agency, and Japan Aerospace Exploration Agency. It is to be launched into a Sun-Earth L2 orbit in 2021. One of the most challenging aspects of the mission is the construction of a flight mirror assembly capable focusing X-rays in the band of 0.1 to 40 keY with an angular resolution of better than 5 arc-seconds and with an effective collection area of more than 3 sq m. The mirror assembly will consist of approximately 15,000 parabolic and hyperbolic mirror segments, each of which is approximately 200mm by 300mm with a thickness of 0.4mm. The manufacture and qualification of these mirror segments and their integration into the giant mirror assembly have been the objectives of a vigorous technology development program at NASA's Goddard Space Flight Center. Each of these mirror segments needs to be measured and qualified for both optical figure and mechanical dimensions. In this talk, I will describe the technology program with a particular emphasis on a measurement system we are developing to meet those requirements, including the use of coordinate measuring machines, Fizeau interferometers, and custom-designed, and -built null lens. This system is capable of measuring highly off-axis aspherical or cylindrical mirrors with repeatability, accuracy, and speed.

  8. LED structure with enhanced mirror reflectivity

    DOEpatents

    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.

  9. Design for Underwater Aplanatic Straubel Acoustic Mirror

    NASA Astrophysics Data System (ADS)

    Sato, Yuji; Mizutani, Koichi; Wakatsuki, Naoto; Nakamura, Toshiaki

    2011-07-01

    An aplanatic Fresnel lens was developed in a previous study to reduce the thickness of underwater acoustic lenses. Showing better convergence properties than aplanatic biconvex and hyperbolic Fresnel lenses, the aplanatic Fresnel lens had limitations in terms of frequency and number of waves owing to its shape. An underwater aplanatic Straubel acoustic mirror, the concept o which is based on a Straubel mirror, was designed to remove the two limitations of aplanatic Fresnel lenses. When the lens is used for underwater imaging sonar, the range resolution deteriorates because of these problems. The shape of the aplanatic Straubel mirror was designed using a numerical optimization method, and its convergence properties were evaluated in simulations. The mirror could correct spherical and coma aberrations in accordance with ray theory. In a comparison of the aplanatic Straubel mirror with an aplanatic Fresnel lens, the mirror had less coma aberration and field curvature than the lens. Additionally, the aplanatic Straubel mirror did not have the two limitations of the lens. Therefore, the aplanatic Straubel mirror showed better convergence than the aplanatic Fresnel lens.

  10. The Mirror Neuron System and Action Recognition

    ERIC Educational Resources Information Center

    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…

  11. Hands-On Discovery of Mirror Planes.

    ERIC Educational Resources Information Center

    Moore, Deborah A.; Cortes-Figueroa, Jose E.

    2001-01-01

    In the study of chemical applications of group theory, some students find it difficult to identify the symmetry elements in a simple geometrical figure or molecular model. Suggests that pattern blocks and mirrors can identify mirror planes in geometrical figures to help students construct, develop, and explain concepts of symmetry elements. (ASK)

  12. Foil Panel Mirrors for Nonimaging Applications

    NASA Technical Reports Server (NTRS)

    Kuyper, D. J.; Castillo, A. A.

    1984-01-01

    Large durable, lightweight mirrors made by bonding thick aluminum foil to honeycomb panels or other rigid, flat backings. Mirrors suitable for use as infrared shields, telescope doors, solar-furnance doors, advertising displays, or other reflectors that require low thermal emissivity and high specularity but do not require precise surface figure necessary for imaging.

  13. Naive Optics: Acting on Mirror Reflections

    ERIC Educational Resources Information Center

    Hecht, Heiko; Bertamini, Marco; Gamer, Matthias

    2005-01-01

    It is known that naive observers have striking misconceptions about mirror reflections. In 5 experiments, this article systematically extends the findings to graphic stimuli, to interactive visual tasks, and finally to tasks involving real mirrors. The results show that the perceptual knowledge of nonexpert adults is far superior to their…

  14. Technology for large tandem mirror experiments

    SciTech Connect

    Thomassen, K.I.

    1980-09-04

    Construction of a large tandem mirror (MFTF-B) will soon begin at Lawrence Livermore National Laboratory (LLNL). Designed to reach break-even plasma conditions, the facility will significantly advance the physics and technology of magnetic-mirror-based fusion reactors. This paper describes the objectives and the design of the facility.

  15. Thermal loading considerations for synchrotron radiation mirrors

    SciTech Connect

    Holdener, F.R.; Berglin, E.J.; Fuchs, B.A.; Humpal, H.H.; Karpenko, V.P.; Martin, R.W.; Tirsell, K.G.

    1986-03-26

    Grazing incidence mirrors used to focus synchrotron radiation beams through small distant apertures have severe optical requirements. The surface distortion due to heat loading of the first mirror in a bending magnet beam line is of particular concern when a large fraction of the incident beam is absorbed. In this paper we discuss mirror design considerations involved in minimizing the thermal/mechanical loading on vertically deflecting first surface mirrors required for SPEAR synchrotron radiation beam lines. Topics include selection of mirror material and cooling method, the choice of SiC for the substrate, optimization of the thickness, and the design of the mirror holder and cooling mechanism. Results obtained using two-dimensional, finite-element thermal/mechanical distortion analysis are presented for the case of a 6/sup 0/ grazing incidence SiC mirror absorbing up to 260 W at Beam Line VIII on the SPEAR ring. Test descriptions and results are given for the material used to thermally couple this SiC mirror to a water-cooled block. The interface material is limited to applications for which the equivalent normal heat load is less than 20 W/cm/sup 2/.

  16. Unbroken Mirror Neurons in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    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…

  17. Three-point spherical mirror mount

    DOEpatents

    Cutburth, Ronald W.

    1990-01-01

    A three-point spherical mirror mount for use with lasers is disclosed. The improved mirror mount is adapted to provide a pivot ring having an outer surface with at least three spaced apart mating points to engage an inner spherical surface of a support housing.

  18. Three-point spherical mirror mount

    DOEpatents

    Cutburth, R.W.

    1984-01-23

    A three-point spherical mirror mount for use with lasers is disclosed. The improved mirror mount is adapted to provide a pivot ring having an outer surface with at least three spaced apart mating points to engage an inner spherical surface of a support housing.

  19. Development Of Composite Panels For Telescope Mirrors

    NASA Technical Reports Server (NTRS)

    Freeland, Robert E.; Mcelroy, Paul M.; Johnston, Robert D.

    1991-01-01

    Report describes continuing program for development of lightweight hexagonal graphite/epoxy composite panels intended to support precisely curved mirror surfaces assembled into large telescope mirror. Discusses development requirements, technical decisions, fabrication methods, measurements of properties of materials, analytical simulation, and thermal vacuum testing. Telescope flown in orbit around Earth to observe at wavelengths down to 30 micrometers.

  20. 21 CFR 886.1500 - Headband mirror.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Headband mirror. 886.1500 Section 886.1500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... mirror is a device intended to be strapped to the head of the user to reflect light for use...

  1. Optical properties of relativistic plasma mirrors

    PubMed Central

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

    2014-01-01

    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. PMID:24614748

  2. CubeSat deformable mirror demonstration

    NASA Astrophysics Data System (ADS)

    Cahoy, Kerri; Marinan, Anne; Kerr, Caitlin; Cheng, Kezi; Jamil, Sara

    2012-09-01

    The goal of the CubeSat Deformable Mirror Demonstration (DeMi) is to characterize the performance of a small deformable mirror over a year in low-Earth orbit. Small form factor deformable mirrors are a key technology needed to correct optical system aberrations in high contrast, high dynamic range space telescope applications such as space-based coronagraphic direct imaging of exoplanets. They can also improve distortions and reduce bit error rates for space-based laser communication systems. While follow-on missions can take advantage of this general 3U CubeSat platform to test the on-orbit performance of several different types of deformable mirrors, this first design accommodates a 32-actuator Boston Micromachines MEMS deformable mirror.

  3. A ferrofluidic deformable mirror for ophthalmology

    NASA Astrophysics Data System (ADS)

    Macpherson, J. B.; Thibault, S.; Borra, E. F.; Ritcey, A. M.; Carufel, N.; Asselin, D.; Jerominek, H.; Campbell, M. C. W.

    2005-09-01

    Optical aberrations reduce the imaging quality of the human eye. In addition to degrading vision, this limits our ability to illuminate small points of the retina for therapeutic, surgical or diagnostic purposes. When viewing the rear of the eye, aberrations cause structures in the fundus to appear blurred, limiting the resolution of ophthalmoscopes (diagnostic instruments used to image the eye). Adaptive optics, such as deformable mirrors may be used to compensate for aberrations, allowing the eye to work as a diffraction-limited optical element. Unfortunately, this type of correction has not been widely available for ophthalmic applications because of the expense and technical limitations of current deformable mirrors. We present preliminary design and characterisation of a deformable mirror suitable for ophthalmology. In this ferrofluidic mirror, wavefronts are reflected from a fluid whose surface shape is controlled by a magnetic field. Challenges in design are outlined, as are advantages over traditional deformable mirrors.

  4. Mirror Neurons through the Lens of Epigenetics

    PubMed Central

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

    2013-01-01

    The consensus view in mirror neuron research is that mirror neurons comprise a uniform, stable execution-observation matching system. In this article, we argue that, in light of recent evidence, this is, at best, an incomplete and oversimplified view of mirror neurons, whose activity is actually quite 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 extant associative and genetic accounts fail to consider the complexity of genetic and non-genetic interactions, we propose a new Evo-Devo perspective, which predicts that environmental differences early in development, or through sensorimotor training, should produce variations in mirror neuron response patterns, tuning them to the social environment. PMID:23953747

  5. Optical properties of relativistic plasma mirrors.

    PubMed

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

    2014-01-01

    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. PMID:24614748

  6. Mirror-image-induced magnetic modes.

    PubMed

    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. PMID:23194368

  7. Numerical modeling of electroactive polymer mirrors for space applications

    NASA Technical Reports Server (NTRS)

    Bao, X.; Bar-Cohen, Y.; Chang, Z.; Sherrit, S.

    2003-01-01

    A controllable mirror made of single-layer EAP mirror is proposed in this paper. An analytical solution of required voltage distribution for forming a parabolic mirror from a planar film is presented.

  8. [Motion control of moving mirror based on fixed-mirror adjustment in FTIR spectrometer].

    PubMed

    Li, Zhong-bing; Xu, Xian-ze; Le, Yi; Xu, Feng-qiu; Li, Jun-wei

    2012-08-01

    The performance of the uniform motion of the moving mirror, which is the only constant motion part in FTIR spectrometer, and the performance of the alignment of the fixed mirror play a key role in FTIR spectrometer, and affect the interference effect and the quality of the spectrogram and may restrict the precision and resolution of the instrument directly. The present article focuses on the research on the uniform motion of the moving mirror and the alignment of the fixed mirror. In order to improve the FTIR spectrometer, the maglev support system was designed for the moving mirror and the phase detection technology was adopted to adjust the tilt angle between the moving mirror and the fixed mirror. This paper also introduces an improved fuzzy PID control algorithm to get the accurate speed of the moving mirror and realize the control strategy from both hardware design and algorithm. The results show that the development of the moving mirror motion control system gets sufficient accuracy and real-time, which can ensure the uniform motion of the moving mirror and the alignment of the fixed mirror. PMID:23156801

  9. Mirror Modes in the Heliosheath

    SciTech Connect

    Tsurutani, B. T.; Guarnieri, F. L.; Echer, E. E.; Lakhina, G. S.; Verkhoglyadova, O. P.

    2011-01-04

    Mirror mode (MM) structures are identified in the Voyager 1 heliosheath magnetic field data. Their characteristics are: (1) quasiperiodic structures with a typical scale size of {approx}57 {rho}{sub p}(proton gyroradii), (2) little or no angular changes across the structures ({approx}3 deg. longitude and {approx}3 deg. latitude), and (3) a lack of sharp boundaries at the magnetic dip edges. It is proposed that the pickup of interstellar neutrals in the upstream region of the termination shock (TS) is the likely cause of MM instability during intervals when the IMF is nearly orthogonal to the solar wind flow direction. Concomitant (quasiperpendicular) shock compression of the MM structures at the TS and additional injection of pickup ions (PUIs) throughout the heliosheath will enhance MM growth.

  10. Durable silver coating for mirrors

    DOEpatents

    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. Deformable Mirror Materials Issue Assessment

    SciTech Connect

    Rudd, R E

    2008-05-27

    It was a pleasure to speak with you and Dr. Olivier Guyon about your project to develop a coronagraph and in particular about materials science considerations in the development of the deformable mirror (DM) for the coronagraph. The coronagraph application will demand more of a DM than previous applications with regard to precision, and since the characterization and modeling tools are currently under development, you asked me to comment on materials issues that might impact the DM design and testing. I have not conducted research on this question, and my own research on modeling MEMS has not included DM systems. I am only in a position to discuss some general considerations that may help in developing a research plan for the DM system. As I understand it, the relevant points about the DM system are as follows. The DM surface needs to be positioned to less than 1 {angstrom} RMS of the desired shape, and be stable to 0.3 {angstrom} RMS for an hour. In the ultimate application in space the stability requirements may be greater. For example, the DM shape can be set using a bright star and then allow the coronagraph to be turned to a dim star to collect data for several hours, counting on the mirror shape to be stable. The DM is made of a polysilicon membrane coated with one or more metal layers for the reflective surface and actuated by 32x32 or 64x64 electrostatic actuators on the back side. The uncertainty in the position of any one actuator should be at the few-picometer level or less averaged over the 300-{micro}m region of the actuator. Currently, experiments are conducted that can characterize the surface shape to the 1 nm level, and it is anticipated that the experiments will be able to characterize the shape at the sub-Angstrom level but not in the immediate future. Regarding stability, under relatively large deformations (10's of nm), the DM mirror surface shows no hysteresis at the measurable nm level. Let me begin by saying that I am not aware of any

  12. Ion microstability in tandem mirrors

    SciTech Connect

    Pearlstein, L.D.

    1983-08-29

    The formalism describing ion-cyclotron modes in mirror traps will be developed. Emphasis will be placed on the effects of finite axial boundaries on the normal modes of the system. Wave properties are a composite picture of: positive energy waves (plasma oscillation, shear Alfven and drift waves), negative energy waves (ion Bernstein waves in a loss-cone media), positive dissipation (electron Landau damping, outgoing waves), and negative dissipation (ion cyclotron damping in a loss-cone and anisotropic temperature medium). Stability boundaries in this bounded media is affected by scale lengths along the magnetic field; first, because they determine the widths of the resonances, and second, because they restrict the parallel structure of the modes.

  13. Qualifying parabolic mirrors with deflectometry

    NASA Astrophysics Data System (ADS)

    Burke, J.; Li, W.; Heimsath, A.; von Kopylow, C.; Bergmann, R. B.

    2013-02-01

    Phase-measuring deflectometry is a full-field gradient technique that lends itself very well to testing reflective optical surfaces. In the past, the industry's interest has been focussed mainly on the detection of defects and ripples, since it is easy to achieve sensitivity in the nm range. On the other hand, attempts to reconstruct the absolute surface shape from the gradient map have been plagued by systematic errors that accumulate to unacceptable uncertainties during data integration. Recently, thanks to improved measurement and evaluation techniques, the state of the art in absolute surface measurement has reached a level of maturity that allows its practical usage in precision optical manufacturing and qualification systems. We demonstrate the techniques, and the progress, by way of results from mirrors for telescopes, solar concentrators, and precision laboratory assemblies.

  14. Toward a large lightweight mirror for AO: development of a 1m Ni coated CFRP mirror

    NASA Astrophysics Data System (ADS)

    Thompson, S. J.; Doel, A. P.; Brooks, D.; Strangwood, M.

    2008-07-01

    We present our recent developments towards the construction of a large, thin, single-piece mirror for adaptive optics (AO). Our current research program aims to have completed fabrication and testing of a 1m diameter, nickel coated carbon-fibre reinforced cyanate ester resin mirror by the last quarter of 2009. This composite mirror material is being developed to provide a lightweight and robust alternative to thin glass shell mirrors, with the challenge of future large deformable mirrors such as the 2.5m M4 on the E-ELT in mind. A detailed analysis of the material properties of test mirror samples is being performed at the University of Birmingham (UK), the first results of which are discussed and presented here. We discuss the project progress achieved so far, including fabrication of the 1m flat moulds for the replication process, manufacturing and testing methods for 20 cm diameter sample mirrors and system simulations.

  15. Correction of an active space telescope mirror using a gradient approach and an additional deformable mirror

    NASA Astrophysics Data System (ADS)

    Allen, Matthew R.; Kim, Jae Jun; Agrawal, Brij N.

    2015-09-01

    High development cost is a challenge for space telescopes and imaging satellites. One of the primary reasons for this high cost is the development of the primary mirror, which must meet diffraction limit surface figure requirements. Recent efforts to develop lower cost, lightweight, replicable primary mirrors include development of silicon carbide actuated hybrid mirrors and carbon fiber mirrors. The silicon carbide actuated hybrid mirrors at the Naval Postgraduate School do not meet the surface quality required for an optical telescope due to high spatial frequency residual surface errors. A technique under investigation at the Naval Postgraduate School is to correct the residual surface figure error using a deformable mirror in the optical path. We present a closed loop feedback gradient controller to actively control a SMT active segment and an additional deformable mirror to reduce residual wavefront error. The simulations and experimental results show that the gradient controller reduces the residual wavefront error more than an integral controller.

  16. Mirror versus parallel bimanual reaching

    PubMed Central

    2013-01-01

    Background In spite of their importance to everyday function, tasks that require both hands to work together such as lifting and carrying large objects have not been well studied and the full potential of how new technology might facilitate recovery remains unknown. Methods To help identify the best modes for self-teleoperated bimanual training, we used an advanced haptic/graphic environment to compare several modes of practice. In a 2-by-2 study, we compared mirror vs. parallel reaching movements, and also compared veridical display to one that transforms the right hand’s cursor to the opposite side, reducing the area that the visual system has to monitor. Twenty healthy, right-handed subjects (5 in each group) practiced 200 movements. We hypothesized that parallel reaching movements would be the best performing, and attending to one visual area would reduce the task difficulty. Results The two-way comparison revealed that mirror movement times took an average 1.24 s longer to complete than parallel. Surprisingly, subjects’ movement times moving to one target (attending to one visual area) also took an average of 1.66 s longer than subjects moving to two targets. For both hands, there was also a significant interaction effect, revealing the lowest errors for parallel movements moving to two targets (p < 0.001). This was the only group that began and maintained low errors throughout training. Conclusion Combined with other evidence, these results suggest that the most intuitive reaching performance can be observed with parallel movements with a veridical display (moving to two separate targets). These results point to the expected levels of challenge for these bimanual training modes, which could be used to advise therapy choices in self-neurorehabilitation. PMID:23837908

  17. Archetypal-imaging and mirror-gazing.

    PubMed

    Caputo, Giovanni B

    2014-03-01

    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

  18. Large thin adaptive x-ray mirrors

    NASA Astrophysics Data System (ADS)

    Doel, Peter; Atkins, Carolyn; Thompson, Samantha; Brooks, David; Yao, Jun; Feldman, Charlotte; Willingale, Richard; Button, Tim; Zhang, Dou; James, Ady

    2007-09-01

    This paper describes the progress made in a proof of concept study and recent results of a research program into large active x-ray mirrors that is part of the UK Smart X-ray Optics project. The ultimate aim is to apply the techniques of active/adaptive optics to the next generation of nested shell astronomical X-ray space telescopes. A variety of deformable mirror technologies are currently available, the most promising of which for active X-ray mirrors are probably unimorph and bimorph piezoelectric mirrors. In this type of mirror one or more sheets of piezoelectric material are bonded to or coated with a passive reflective layer. On the back or between the piezoceramic layer/layers are series of electrodes. Application of an electric field causes the piezoelectric material to undergo local deformation thus changing the mirror shape. Starting in 2005 a proof of concept active mirror research program has been undertaken. This work included modelling and development of actively controlled thin shell mirrors. Finite element models of piezo-electric actuated mirrors have been developed and verified against experimental test systems. This has included the modelling and test of piezo-electric hexagonal unimorph segments. Various actuator types and low shrinkage conductive bonding methods have been investigated and laboratory tests of the use of piezo-electric actuators to adjust the form of an XMM-Newton space telescope engineering model mirror shell have been conducted and show that movement of the optics at the required level is achievable. Promising technological approaches have been identified including moulded piezo-ceramics and piezo-electrics fibre bundles.

  19. Mirror Figuring Techniques of Sir William Herschel

    NASA Astrophysics Data System (ADS)

    Albin, E. F.

    2004-05-01

    Between the years 1773 to 1818, Sir William Herschel constructed dozens of speculum telescope mirrors, with diameters ranging from 6 - 48 inches. Very little, if any, detailed information has ever been published on the specifics of his mirror figuring efforts. The reason for this certainly relates to his desire to closely guard mirror production trade secrets. Upon Herschel's death, all telescope-making documents were passed on to his only son, Sir John Herschel. These materials are now in the possession of the British RAS and primarily consist of: a) a four volume series entitled "Experiments on the Construction of Specula," b) a 129 page treaty called "On the Construction of Specula," and c) a 179 page manuscript entitled "Results of Experiments on the Construction of Mirrors." It is suggested that publication was further delayed and then eventually abandoned due to silver-coated glass mirrors coming into favor. A recent investigation by the author, of the unpublished manuscripts on the construction of specula, suggests that Herschel's mirror figuring techniques did not involve any guess work; in fact, his methods were highly refined -- never leaving to chance the evolution of a spherical surface into the required paraboloid. At the heart of Herschel's figuring techniques were a series of aperture diaphragms (similar to the Couder masks used by modern telescope makers) that were placed over the mirror, which allowed for the precise determination of its curvature at various predefined zones. With this information, Herschel was able to vary his figuring strokes with his polishing tool accordingly. In addition, all mirrors were subsequently "star tested," sometimes with aperture diaphragms in place, allowing for field examination of the mirror's "distinctness" or performance. Double stars and the planet Saturn were favorite targets used to analyze and then correct a mirror's figure.

  20. Lightweight deformable mirrors for future space telescopes

    NASA Astrophysics Data System (ADS)

    Patterson, Keith

    This thesis presents a concept for ultra-lightweight deformable mirrors based on a thin substrate of optical surface quality coated with continuous active piezopolymer layers that provide modes of actuation and shape correction. This concept eliminates any kind of stiff backing structure for the mirror surface and exploits micro-fabrication technologies to provide a tight integration of the active materials into the mirror structure, to avoid actuator print-through effects. Proof-of-concept, 10-cm-diameter mirrors with a low areal density of about 0.5 kg/m2 have been designed, built and tested to measure their shape-correction performance and verify the models used for design. The low cost manufacturing scheme uses replication techniques, and strives for minimizing residual stresses that deviate the optical figure from the master mandrel. It does not require precision tolerancing, is lightweight, and is therefore potentially scalable to larger diameters for use in large, modular space telescopes. Other potential applications for such a laminate could include ground-based mirrors for solar energy collection, adaptive optics for atmospheric turbulence, laser communications, and other shape control applications. The immediate application for these mirrors is for the Autonomous Assembly and Reconfiguration of a Space Telescope (AAReST) mission, which is a university mission under development by Caltech, the University of Surrey, and JPL. The design concept, fabrication methodology, material behaviors and measurements, mirror modeling, mounting and control electronics design, shape control experiments, predictive performance analysis, and remaining challenges are presented herein. The experiments have validated numerical models of the mirror, and the mirror models have been used within a model of the telescope in order to predict the optical performance. A demonstration of this mirror concept, along with other new telescope technologies, is planned to take place during

  1. Archetypal-Imaging and Mirror-Gazing

    PubMed Central

    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

  2. Impedance Matched to Vacuum, Invisible Edge, Diffraction Suppressed Mirror

    NASA Technical Reports Server (NTRS)

    Hagopian, John G. (Inventor); Roman, Patrick A. (Inventor); Shiri, Sharham (Inventor); Wollack, Edward J. (Inventor)

    2015-01-01

    Diffraction suppressed mirrors having an invisible edge are disclosed for incident light at both targeted wavelengths and broadband incident light. The mirrors have a first having at least one discontiguous portion having a plurality of nanostructured apertures. The discontiguous mirror portion impedance matches a relatively high impedance portion of the mirror to a relatively low impedance portion of the mirror, thereby reducing the diffraction edge effect otherwise present in a conventional mirror.

  3. Double arch mirror study. Part 3: Fabrication and test report

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    A method of mounting a cryogenically cooled, lightweight, double arch, glass mirror was developed for infrared, astronomical telescopes such as the Space Infrared Telescope Facility (SIRTF). A 50 cm, fused silica mirror which was previously fabricated was modified for use with a new mount configuration. This mount concept was developed. The modification of the mirror, the fabrication of the mirror mount, and the room temperature testing of the mounted mirror are reported. A design for a SIRTF class primary mirror is suggested.

  4. Trapped Particle Instabilities in the Kinetically Stabilized Tandem Mirror

    NASA Astrophysics Data System (ADS)

    Pratt, J.; Berk, H. L.; Horton, W.

    2009-05-01

    The kinetically stabilized tandem mirror (KSTM) is an innovative design to stabilize MHD modes in an axially symmetric tandem mirror machine (Post, J. Fus. Energy 2007). Originally proposed by Ryutov (Ryutov, Proc. of Course and Workshop, Varenna, Italy, 1987), this stabilizer has been empirically verified in the Gas Dynamic Trap (Ivanov, Anakeev et.al. Trans. Fusion Technology. 39, 127, 2001). The KSTM uses the momentum flux of escaping particles that sample good magnetic-field-line-curvature region outside the central confinement region. Charged ion beams at relatively low energy are externally injected from the ends into the expander region at an energy that is consistent with a stable MHD prediction and acceptable power loss for fusion. If stable, the KSTM would be extremely useful for limiting radial diffusion since the chaotic step size is minimized. We confirm that MHD stability is achieved in the KSTM. We examine the effect of the trapped particle instability discussed in Berk, Rosenbluth, et al. Sov. J. Plasma Phys. 1983 on overall stability. In this case stability is very sensitive to the electron connection between the stabilizer and the end plug.

  5. Vacuum vessel for the tandem Mirror Fusion Test Facility

    SciTech Connect

    Gerich, J.W.

    1986-03-10

    In 1980, the US Department of Energy gave the Lawrence Livermore National Laboratory approval to design and build a tandem Mirror Fusion Test Facility (MFTF-B) to support the goals of the National Mirror Program. We designed the MFTF-B vacuum vessel both to maintain the required ultrahigh vacuum environment and to structurally support the 42 superconducting magnets plus auxiliary internal and external equipment. During our design work, we made extensive use of both simple and complex computer models to arrive at a cost-effective final configuration. As part of this work, we conducted a unique dynamic analysis to study the interaction of the 32,000-tonne concrete-shielding vault with the 2850-tonne vacuum vessel system. To maintain a vacuum of 2 x 10/sup -8/ torr during the physics experiments inside the vessel, we designed a vacuum pumping system of enormous capacity. The vacuum vessel (4200-m/sup 3/ internal volume) has been fabricated and erected, and acceptance tests have been completed at the Livermore site. The rest of the machine has been assembled, and individual systems have been successfully checked. On October 1, 1985, we began a series of integrated engineering tests to verify the operation of all components as a complete system.

  6. Current status of the gasdynamic mirror fusion propulsion experiment

    NASA Astrophysics Data System (ADS)

    Emrich, William J.

    2002-01-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). An experimental GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. An initial shakedown of the device is currently underway with initial experiments slated to occur in late 2001. This device would operate at much higher plasma densities and with much larger L/D ratios than previous mirror machines. The high L/D ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. The high plasma density results in the plasma behaving much more like a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with ``loss cone'' microinstabilities. The device has been constructed to allow a considerable degree of flexibility in its configuration thus permitting the experiment to grow over time without necessitating a great deal of additional fabrication. .

  7. Current Status of the Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.

    2002-01-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). An experimental GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. An initial shakedown of the device is currently underway with initial experiments slated to occur in late 2001. This device would operate at much higher plasma densities and with much larger L/D ratios than previous mirror machines. The high L/D ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. The high plasma density results in the plasma behaving much more like a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with 'loss cone' microinstabilities. The device has been constructed to allow a considerable degree of flexibility in its configuration thus permitting the experiment to grow over time without necessitating a great deal of additional fabrication.

  8. System Description of the Gasdynamic Mirror Propulsion System

    NASA Technical Reports Server (NTRS)

    Emrich, William Jr.; Rodgers, Stephen L (Technical Monitor)

    2002-01-01

    Nuclear fusion appears to be a most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be very well suited for fusion propulsion applications is the gasdynamic mirror (GDM). An experimental GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. A systems shakedown of the device is currently underway with initial experiments slated to occur in early 2002. The device has been constructed so as to allow a considerable degree of flexibility in its configuration thus permitting the experiment to easily grow over time without necessitating a great deal of additional fabrication. This flexibility is due in large part to the modular nature of the machine wherein additional modules may be added as needed to meet varying experimental objectives. Figure 1 shows the current configuration of the Gasdynamic Mirror Experiment, and Table 1 describes the main features of the device.

  9. Perspex machine: VII. The universal perspex machine

    NASA Astrophysics Data System (ADS)

    Anderson, James A. D. W.

    2006-01-01

    The perspex machine arose from the unification of projective geometry with the Turing machine. It uses a total arithmetic, called transreal arithmetic, that contains real arithmetic and allows division by zero. Transreal arithmetic is redefined here. The new arithmetic has both a positive and a negative infinity which lie at the extremes of the number line, and a number nullity that lies off the number line. We prove that nullity, 0/0, is a number. Hence a number may have one of four signs: negative, zero, positive, or nullity. It is, therefore, impossible to encode the sign of a number in one bit, as floating-point arithmetic attempts to do, resulting in the difficulty of having both positive and negative zeros and NaNs. Transrational arithmetic is consistent with Cantor arithmetic. In an extension to real arithmetic, the product of zero, an infinity, or nullity with its reciprocal is nullity, not unity. This avoids the usual contradictions that follow from allowing division by zero. Transreal arithmetic has a fixed algebraic structure and does not admit options as IEEE, floating-point arithmetic does. Most significantly, nullity has a simple semantics that is related to zero. Zero means "no value" and nullity means "no information." We argue that nullity is as useful to a manufactured computer as zero is to a human computer. The perspex machine is intended to offer one solution to the mind-body problem by showing how the computable aspects of mind and, perhaps, the whole of mind relates to the geometrical aspects of body and, perhaps, the whole of body. We review some of Turing's writings and show that he held the view that his machine has spatial properties. In particular, that it has the property of being a 7D lattice of compact spaces. Thus, we read Turing as believing that his machine relates computation to geometrical bodies. We simplify the perspex machine by substituting an augmented Euclidean geometry for projective geometry. This leads to a general

  10. Fabrication of metal mirror modules for snap-together VIS telescopes

    NASA Astrophysics Data System (ADS)

    Beier, Matthias; Hartung, Johannes; Kinast, Jan; Gebhardt, Andreas; Burmeister, Frank; Zeitner, Uwe D.; Risse, Stefan; Eberhardt, Ramona; Tünnermann, Andreas

    2015-10-01

    The assembly effort of an optical system naturally relies on the degrees of freedom and the maximum allowable tolerances each optical surface introduces into the overall budget. Snap-together approaches traditionally can be regarded as attractive solutions for IR systems having moderate tolerances, where the required precision is achieved by simultaneously machining optical surfaces and mounting interfaces in a single machine setup. Recent improvements in manufacturing and metrology enable a transfer of the assembly approach to shorter wavelength applications, where sub-aperture figuring techniques are used in combination with suitable amorphous polishing layers to achieve the increased requirements on figure and finish. A further decrease of the assembly effort is gained by machining several optical surfaces on common mechanical substrates and fixing the relative position with uncertainties as low as the machine precision. The article presents the fabrication of large electroless nickel coated aluminum mirror modules having two functional freeform surfaces and references for metrology and system integration. The modules are part of an all metal anamorphic imaging telescope operating in the visual spectral range. Presented methods open up a rapid and reliable assembly of metal mirror based VIS telescopes to be used in ground and space based astronomy or remote sensing applications.

  11. Kinetically Stabilized Axisymmetric Tandem Mirrors: Summary of Studies

    SciTech Connect

    Post, R F

    2005-02-08

    probability of so-called ''temperature-gradient'' instabilities, known to be endemic to closed systems. Finally, the open-ended nature of the field readily allows the control of the radial potential distribution, a circumstance that has been shown, for example in the Gamma 10 tandem-mirror experiment at Tsukuba Japan, to suppress drift-type instability modes. Standing against all of these attractive properties of axisymmetric mirror-based systems is the fact, shown early on, that such systems are prone to MHD ''interchange'' instabilities, one in which the plasma column drifts transversely, at a rate far above classical transport. Observed early on, the ''cure'' that was universally adopted, as first demonstrated in the famous ''Ioffe experiment'', was to abandon axisymmetry and employ so-called ''magnetic-well'' fields, ones in which the field increases radially and axially from its interior, strongly suppressing the MHD interchange mode, up to plasma ''beta'' values approaching unity, observed in the 2X2B experiment. When the tandem mirror concept was introduced in 1976 every experiment that was constructed employed various combinations of non-axisymmetric coil configurations (''Baseball,'' and ''Yin-Yang'' coils) to create the magnetic fields. But it came at a heavy price: non-axisymmetric fields gave rise to new non-classical loss channels, and the complexity of the fields introduced difficult engineering problems. It was well recognized at the time that it would be highly advantageous to preserve axisymmetry of the tandem mirror coils, but there was no apparent way to stabilize the ubiquitous MHD interchange mode. A decade later a way to accomplish this end was analyzed theoretically, and, a few years later successfully demonstrated experimentally, in the Gas Dynamic Trap (GDT) experiment at Novosibirsk. The concept: the presence of a sufficient amount of plasma on the expanding field lines outside the end mirrors of a mirror machine can act as an ''anchor,'' MHD

  12. A comparison of performance of lightweight mirrors

    NASA Technical Reports Server (NTRS)

    Cho, Myung K.; Richard, Ralph M.; Hileman, Edward A.

    1990-01-01

    Four lightweight solid contoured back mirror shapes (a double arch, a single arch, a modified single arch, and a double concave mirror) and a cellular sandwich lightweight meniscus mirror, have been considered for the primary mirror of the Space Infrared Telescope Facility (SIRTF). A parametric design study using these shapes for the SIRTF 40 inch primary mirror with a focal ratio f/2 is presented. Evaluations of the optical performance and fundamental frequency analyses are performed to compare relative merits of each mirror configuration. Included in these are structural, optical, and frequency analyses for (1) different back contour shapes, (2) different number and location of the support points, and (3) two gravity orientations (ZENITH and HORIZON positions). The finite element program NASTRAN is used to obtain the structural deflections of the optical surface. For wavefront error analysis, FRINGE and PCFRINGE programs are used to evaluate the optical performance. A scaling law relating the optical and structural performance for various mirror contoured back shapes is developed.

  13. Towards plasma cleaning of ITER first mirrors

    NASA Astrophysics Data System (ADS)

    Moser, L.; Marot, L.; Eren, B.; Steiner, R.; Mathys, D.; Leipold, F.; Reichle, R.; Meyer, E.

    2015-06-01

    To avoid reflectivity losses in ITER's optical diagnostic systems, on-site cleaning of metallic first mirrors via plasma sputtering is foreseen to remove deposit build-ups migrating from the main wall. In this work, the influence of aluminium and tungsten deposits on the reflectivity of molybdenum mirrors as well as the possibility to clean them with plasma exposure is investigated. Porous ITER-like deposits are grown to mimic the edge conditions expected in ITER, and a severe degradation in the specular reflectivity is observed as these deposits build up on the mirror surface. In addition, dense oxide films are produced for comparisons with porous films. The composition, morphology and crystal structure of several films were characterized by means of scanning electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction and secondary ion mass spectrometry. The cleaning of the deposits and the restoration of the mirrors' optical properties are possible either with a Kaufman source or radio frequency directly applied to the mirror (or radio frequency plasma generated directly around the mirror surface). Accelerating ions of an external plasma source through a direct current applied onto the mirror does not remove deposits composed of oxides. A possible implementation of plasma cleaning in ITER is addressed.

  14. Laser cleaning of ITER's diagnostic mirrors

    NASA Astrophysics Data System (ADS)

    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.

  15. Compliant deformable mirror approach for wavefront improvement

    NASA Astrophysics Data System (ADS)

    Clark, James H.; Penado, F. Ernesto

    2016-04-01

    We describe a compliant static deformable mirror approach to reduce the wavefront concavity at the Navy Precision Optical Interferometer (NPOI). A single actuator pressing on the back surface of just one of the relay mirrors deforms the front surface in a correcting convex shape. Our design uses the mechanical advantage gained from a force actuator sandwiched between a rear flexure plate and the back surface of the mirror. We superimpose wavefront contour measurements with our finite element deformed mirror model. An example analysis showed improvement from 210-nm concave-concave wavefront to 51-nm concave-concave wavefront. With our present model, a 100-nm actuator increment displaces the mirror surface by 1.1 nm. We describe the need for wavefront improvement that arises from the NPOI reconfigurable array, offer a practical design approach, and analyze the support structure and compliant deformable mirror using the finite element method. We conclude that a 20.3-cm-diameter, 1.9-cm-thick Zerodur® mirror shows that it is possible to deform the reflective surface and cancel out three-fourths of the wavefront deformation without overstressing the material.

  16. A Deployable Primary Mirror for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Phelps, James E.; Dyer, Jack E.; Caudle, David A.; Tam, Anthony; Escobedo, Javier; Kasl, Eldon P.

    1999-01-01

    NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (light direction a nd ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55- m-diameter, proof-of-concept mirror. Keywords: precision deployment, hinge joint, latch joint, deployable structures, fabrication, space telescopes, optical instruments, microdynamics.

  17. Active polishing technology for large aperture aspherical mirror and ultra thin mirror

    NASA Astrophysics Data System (ADS)

    Cui, Xaingqun; Gao, Bilie; Li, Xinnan

    2006-02-01

    Some results on active polishing technology for large aperture aspherical mirrors and ultra thin mirrors, which have been developed in recent years in Nanjing Institute of Astronomical Optics and Technology, CAS, are presented in this paper. There are two polishing methods developed for the large aperture ultra thin mirrors with two different trial mirrors respectively. One is a hexagonal mirror with diagonal size of 1100mm, and thickness of 25mm by no-separate support method specially for polish the sub-mirror of Schmidt corrector of LAMOST, which is a national large scientific project of China. Another is a circular mirror with 1035mm in diameter and 26mm in thickness by active support method. The active stressed polishing technology developed for large aperture aspherical mirror with fast f ratio, and a paraboloidal mirror with a diameter of 910mm and an f ratio 2 as was successfully polished. The computer controlled polishing is also different from the normal way in the system. Some complicated aspects were added. The results showed the final surface accuracy of all these trial mirrors is better than expected requirements for normal application in astronomical telescopes.

  18. Degradation of back surface acrylic mirrors for low concentration and mirror-augmented photovoltaics

    NASA Astrophysics Data System (ADS)

    Murray, Myles P.; Bruckman, Laura S.; Gordon, Devin; Richardson, Samuel; Reinbolt, Greg; Schuetz, Mark; French, Roger H.

    2012-10-01

    Back-surface acrylic mirrors can be used in low concentration and mirror augmented photovoltaics (LCPV, MAPV) to increase the irradiance on a module. Back-surface mirrors can spectrally filter incoming solar radiation reducing the ultraviolet (UV) and infrared (IR) load on the module, while useful radiation is coupled into a module or photovoltaic cell. Degradation of these mirrors can occur from UV induced photodegradative processes and metallization corrosion. Environmental stresses such as humidity, thermal cycling and exposure to corrosive substances can cause an increase in scattering, reducing mirror performance. In order to increase the lifetime and durability of back-surface acrylic mirrors a better understanding of the degradation modes is necessary. In a study of acrylic back-surface mirrors for LCPV and MAPV applications, optical properties and bidirectional scattering distribution functions (BSDF) were investigated and correlated to simulated exposure protocols. Formulations of Poly(methyl methacrylate) (PMMA) with differing concentration of UV absorbers were used for the aluminum backsurface acrylic mirrors. The formulations of aluminum back-surface acrylic mirrors were exposed in a QUV accelerated weathering tester (QLabs) to ASTM G154 Cycle 4. Total and diffuse reflectance spectra were measured for each mirror under exposure using a diffuse reflectance accessory (DRA) from 180-1800 nm on a Varian Cary 6000i at defined dose intervals. The total reflectance losses in the 250-400 nm region were greater and diffuse-only reflectance increased for formulations of acrylic mirrors that contained the least amount of UV stabilizer after each dose of QUV exposure. Acrylic back-surface mirrors were exposed to salt fog corrosion and QUV and were analyzed using BSDF. There was an increase in scattering from roughening of the mirror surface after exposure to the corrosive environment.

  19. ZERODUR mirror substrates for solar telescopes

    NASA Astrophysics Data System (ADS)

    Döhring, T.; Jedamzik, R.; Hartmann, P.

    The zero-expansion glass ceramic material, ZERODUR, is well known for nighttime telescope mirror substrates. Also for solar telescopes, ZERODUR is often selected as mirror blank material. Examples are the Swedish 1m Solar Telescope (SST), the balloon-born telescope SUNRISE, and the New Solar Telescope (NST) of the Big Bear Solar Observatory. The properties of ZERODUR are discussed with respect to the special technical requirements of solar observatories, resulting in the conclusion that mirrors made of this glass ceramic material are an excellent choice for solar telescopes.

  20. CVD silicon carbide mirrors for EUV applications

    NASA Astrophysics Data System (ADS)

    Keski-Kuha, Ritva A.; Osantowski, John F.; Leviton, Douglas B.; Saha, Timo T.; Wright, Geraldine A.; Boucarut, Rene A.; Fleetwood, Charles M.; Madison, Timothy J.

    1995-10-01

    Advances in optical coating and materials technology have made possible the development of instruments with substantially improved efficiency in the extreme ultraviolet (EUV). For example, the development of chemical vapor deposited (CVD) SiC mirrors provides an opportunity to extend the range of normal incidence instruments down to 60 nm. CVD-SiC is a highly polishable material yielding low scatter surfaces. High UV reflectivity and desirable mechanical and thermal properties make CVD-SiC an attractive mirror and/or coating material for EUV applications. The EUV performance of SiC mirrors as well as some strengths and problem areas are discussed.

  1. Tandem Mirror Reactor Systems Code (Version I)

    SciTech Connect

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.; Barrett, R.J.; Gorker, G.E.; Spampinaton, P.T.; Bulmer, R.H.; Dorn, D.W.; Perkins, L.J.; Ghose, S.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost.

  2. Fine alignment of a large segmented mirror

    NASA Technical Reports Server (NTRS)

    Dey, Thomas William (Inventor)

    2010-01-01

    A system for aligning a segmented mirror includes a source of radiation directed along a first axis to the segmented mirror and a beamsplitter removably inserted along the first axis for redirecting radiation from the first axis to a second axis, substantially perpendicular to the first axis. An imaging array is positioned along the second axis for imaging the redirected radiation, and a knife-edge configured for cutting the redirected radiation is serially positioned to occlude and not occlude the redirected radiation, effectively providing a variable radiation pattern detected by the imaging array for aligning the segmented mirror.

  3. Mirror Symmetry for Quasi-Homogeneous Singularities

    NASA Astrophysics Data System (ADS)

    Rathnakumara, Himal; Jarvis, Tyler

    2008-10-01

    I will present an introduction to mirror symmetry in the context of string theory. Then I will describe an instance of mirror symmetry for singularties defined by quasi-homogeneous polynomials in weighted projective spaces. Milnor rings and the FJRW (Fan-Jarvis-Ruan-Witten) rings associated with these singularities and their relation to the Landua-Ginzburg A model and the Landua-Ginzburg B model will be explained. Results of the calculations for certain singularities for which the mirror symmetry conjecture has been verified will be presented.

  4. Actuated Hybrid Mirrors for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Ealey, Mark; Redding, David

    2010-01-01

    This paper describes new, large, ultra-lightweight, replicated, actively controlled mirrors, for use in space telescopes. These mirrors utilize SiC substrates, with embedded solid-state actuators, bonded to Nanolaminate metal foil reflective surfaces. Called Actuated Hybrid Mirrors (AHMs), they use replication techniques for high optical quality as well as rapid, low cost manufacturing. They enable an Active Optics space telescope architecture that uses periodic image-based wavefront sensing and control to assure diffraction-limited performance, while relaxing optical system fabrication, integration and test requirements. The proposed International Space Station Observatory seeks to demonstrate this architecture in space.

  5. Particle Deconfinement in a Bent Magnetic Mirror

    SciTech Connect

    Renaud Gueroult and Nathaniel J. Fisch

    2012-09-06

    Coils misalignment in a magnetic mirror can produce additional particle transport. The magnetic field non axi-symmetry is responsible for radial and longitudinal drifts in a way much similar to the neo-classical transport in a tandem mirror cell distorted by end plugs. Accordingly, a regime exhibiting large radial displacements - similar to the resonant regime in tandem mirrors - can be obtained by confining ions azimuthally, for example by means of a properly tuned radial electric field. Because of the mass dependence of the magnetic field non-homogeneity drift velocities, the azimuthal trapping is mass specific, allowing in principle the filtering of a specific species based on its mass.

  6. Particle deconfinement in a bent magnetic mirror

    SciTech Connect

    Gueroult, Renaud; Fisch, Nathaniel J.

    2012-11-15

    Coils misalignment in a magnetic mirror can produce additional particle transport. The magnetic field non axi-symmetry is responsible for radial and longitudinal drifts in a way much similar to the neo-classical transport in a tandem mirror cell distorted by end plugs. Accordingly, a regime exhibiting large radial displacements--similar to the resonant regime in tandem mirrors--can be obtained by confining ions azimuthally, for example by means of a properly tuned radial electric field. Because of the mass dependence of the magnetic field non-homogeneity drift velocities, the azimuthal trapping is mass specific, allowing, in principle, the filtering of a specific species based on its mass.

  7. Affect regulation: holding, containing and mirroring.

    PubMed

    Pedersen, Signe Holm; Poulsen, Stig; Lunn, Susanne

    2014-10-01

    Gergely and colleagues' state that their "Social Biofeedback Theory of Parental Affect Mirroring" can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parental affect mirroring may be understood as a specification of these concepts. It is argued that despite similarities at a descriptive level the concepts are embedded in theories with different ideas of subjectivity. Hence an understanding of the concept of affect regulation as a concretization and specification of the classical concepts dilutes the complexity of both the concept of affect regulation and of the classical concepts. PMID:25351730

  8. HCN laser with an adaptive output mirror

    SciTech Connect

    Kamenev, Yu E; Masalov, S A; Filimonova, A A

    2006-09-30

    A device for optimal coupling between a laser resonator and the external medium, having the form of one-dimensional wire grating conjugated with a plane mirror with an aperture, is proposed, developed and tested experimentally. The dependences of the output laser power on the separation between the grating and the mirror, diameter of the aperture in the plane mirror, and the grating period, are studied. The obtained results not only confirm the possibility of using such a coupling device, but also point towards the ways and principles of its application. (lasers)

  9. Machine tool locator

    DOEpatents

    Hanlon, John A.; Gill, Timothy J.

    2001-01-01

    Machine tools can be accurately measured and positioned on manufacturing machines within very small tolerances by use of an autocollimator on a 3-axis mount on a manufacturing machine and positioned so as to focus on a reference tooling ball or a machine tool, a digital camera connected to the viewing end of the autocollimator, and a marker and measure generator for receiving digital images from the camera, then displaying or measuring distances between the projection reticle and the reference reticle on the monitoring screen, and relating the distances to the actual position of the autocollimator relative to the reference tooling ball. The images and measurements are used to set the position of the machine tool and to measure the size and shape of the machine tool tip, and examine cutting edge wear. patent

  10. Fault Tolerant State Machines

    NASA Technical Reports Server (NTRS)

    Burke, Gary R.; Taft, Stephanie

    2004-01-01

    State machines are commonly used to control sequential logic in FPGAs and ASKS. An errant state machine can cause considerable damage to the device it is controlling. For example in space applications, the FPGA might be controlling Pyros, which when fired at the wrong time will cause a mission failure. Even a well designed state machine can be subject to random errors us a result of SEUs from the radiation environment in space. There are various ways to encode the states of a state machine, and the type of encoding makes a large difference in the susceptibility of the state machine to radiation. In this paper we compare 4 methods of state machine encoding and find which method gives the best fault tolerance, as well as determining the resources needed for each method.

  11. ATST telescope mount: telescope of machine tool

    NASA Astrophysics Data System (ADS)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  12. Chaotic Boltzmann machines

    PubMed Central

    Suzuki, Hideyuki; Imura, Jun-ichi; Horio, Yoshihiko; Aihara, Kazuyuki

    2013-01-01

    The chaotic Boltzmann machine proposed in this paper is a chaotic pseudo-billiard system that works as a Boltzmann machine. Chaotic Boltzmann machines are shown numerically to have computing abilities comparable to conventional (stochastic) Boltzmann machines. Since no randomness is required, efficient hardware implementation is expected. Moreover, the ferromagnetic phase transition of the Ising model is shown to be characterised by the largest Lyapunov exponent of the proposed system. In general, a method to relate probabilistic models to nonlinear dynamics by derandomising Gibbs sampling is presented. PMID:23558425

  13. Scaling laws for light weight optics, studies of light weight mirrors mounting and dynamic mirror stress, and light weight mirror and mount designs

    NASA Technical Reports Server (NTRS)

    Vukobratovich, Daniel; Richard, Ralph M.; Valente, Tina M.; Cho, Myung K.

    1990-01-01

    Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature was made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best curve for each case. A best fitting curve program tests nineteen different equations and ranks a goodness-to-fit for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types.

  14. Mirror Advanced Reactor Study interim design report

    SciTech Connect

    Not Available

    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.

  15. Auditory–vocal mirroring in songbirds

    PubMed Central

    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

  16. Wind responses of the LSST secondary mirror

    NASA Astrophysics Data System (ADS)

    Cho, Myung K.; Vogiatzis, Konstantinos; Sebag, Jacques; Neill, Douglas R.

    2012-09-01

    The Large Synoptic Survey Telescope (LSST) optical design calls for a large annular 3.4 m diameter meniscus convex aspheric Secondary Mirror (M2). The M2 has a mass of approximately 1.5 metric tons and the optimized mirror support system consists of 72 axial actuators, mounted at the mirror back surface, and 6 tangent link lateral supports mounted around the outer edge. A fully integrated M2 Finite Element Model (FEM) including the mirror and the support systems has been developed to investigate the performance of the M2 assembly and to determine the image degradation due to dynamic wind loading. Detailed wind response analysis was performed based on the input from Computational Fluid Dynamics (CFD) simulations. Image quality calculations of the time history responses and Power Spectrum Density (PSD) are addressed.

  17. Distortion compensation in interferometric testing of mirrors

    SciTech Connect

    Robinson, Brian M.; Reardon, Patrick J

    2009-01-20

    We present a method to compensate for the imaging distortion encountered in interferometric testing of mirrors, which is introduced by interferometer optics as well as from geometric projection errors. Our method involves placing a mask, imprinted with a regular square grid, over the mirror and finding a transformation that relates the grid coordinates to coordinates in the base plane of the parent surface. This method can be used on finished mirrors since no fiducials have to be applied to the surfaces. A critical step in the process requires that the grid coordinates be projected onto the mirror base plane before the regression is performed. We apply the method successfully during a center-of-curvature null test of an F/2 off-axis paraboloid.

  18. Coating considerations for mirrors of CPV devices

    SciTech Connect

    Schmauder, Torsten; Sauer, Peter; Ickes, Gerd

    2014-09-26

    One of the different optical concepts for concentrator devices is to place a focussing primary mirror behind a transparent front plate. In addition (also in case of Fresnel-diffractive main optics), further 'secondary' reflectors may be used further along the beam path. Such mirrors are usually implemented as coating stacks of a highly reflective metal - usually silver - and protective layers. The protective layers are preferably designed as reflection enhancing interference stack. The design of such protective layer stacks yields two difficulties, which are addressed in this paper: (a) vacuum coating of three-dimensional parts will result in a thickness distribution and the optical design of the stack should thus be tolerant to layer thickness variations, and (b) different places of the mirror will have different angle-of-incidence of the sunlight under operating conditions. As result, the layer stack has a different design at different places of the mirror.

  19. Cold atom reflection from curved magnetic mirrors

    NASA Astrophysics Data System (ADS)

    Hughes, Ifan G.; Barton, P. A.; Boshier, M. G.; Hinds, Edward A.

    1997-05-01

    Multiple bounces of cold rubidium atoms have been observed for times up to one second in a trap formed by gravity and a 2 cm-diameter spherical mirror made from a sinusoidally magnetized floppy disk. We have studied the dynamics of the atoms bouncing in this trap from several different heights up to 40.5 mm and we conclude that the atoms are reflected specularly and with reflectivity 1.01(3). Slight roughness of the mirror is caused by harmonics in the magnetization of the surface and by discontinuities at the boundaries between recorded tracks. As the next step in this atom optics program we propose using a magnetic mirror to create a 2D atomic gas. We discuss how cold atoms can be loaded into the ground state of a static magnetic potential well that exists above the surface of the mirror as a consequence of the intermediate-field Zeeman effect.

  20. Diamond machine tool face lapping machine

    DOEpatents

    Yetter, H.H.

    1985-05-06

    An apparatus for shaping, sharpening and polishing diamond-tipped single-point machine tools. The isolation of a rotating grinding wheel from its driving apparatus using an air bearing and causing the tool to be shaped, polished or sharpened to be moved across the surface of the grinding wheel so that it does not remain at one radius for more than a single rotation of the grinding wheel has been found to readily result in machine tools of a quality which can only be obtained by the most tedious and costly processing procedures, and previously unattainable by simple lapping techniques.

  1. Novel technologies for small deformable mirrors

    NASA Astrophysics Data System (ADS)

    Strachan, Mel; Myers, Richard; Cooke, Kevin; Hampshire, Joanne; Hough, Jim; Rowan, Sheila; van Veggel, Marielle; Kirk, Katherine; Hutson, David; Uzgur, Erman; Kim, Shin-Sung

    2010-07-01

    Adaptive optic requirements for instrumentation such as EAGLE for the European extremely large telescope present an enormous challenge to deformable mirror technology. We have developed a unique approach using fabricated arrays of multilayer actuator technology to address the requirements of actuator density and deflection. Our programme of work has uncovered a novel approach which has led to a built in test capability. We will present the outcomes of our work which we believe will lead to a compact deformable mirror.

  2. Experimental study of solar simulator mirror cryocontamination

    NASA Technical Reports Server (NTRS)

    Galjaev, V. L.; Makarov, A. A.; Afanassiev, N. A.

    1994-01-01

    The background and tasks formulation of the study of Solar Simulator collimation mirror cryocontamination in Large Thermal Vacuum Facility are outlined, research methods and experiment procedures are described, experimental relationships obtained are analyzed and practical recommendations are given. The accepted procedure of thermal vacuum tests as a rule defines the sequence of operations for verifying the spacecraft under test without taking into account measures for preventing Solar Simulator collimation mirror contamination and degradation. On the other hand, evacuation procedures is defined for conditions of achieving the required vacuum in the shortest possible time with using the available evacuation equipment at a regime close to the optimum one. Similarly, cryopanel cooling down cyclogram and test object preparation process are not analyzed from the viewpoint of ways of reducing environmental detrimental effects on thermal vacuum facility contamination-sensitive systems. Solar Simulator mirror contamination and its reflective characteristics change results in degradation of solar flux parameters and reduction of simulator continuous operation time. Methods of consideration of optical effects due to mirror surface contamination are actually missing. The effects themselves are not quite understood and data cited in literature as a rule, were obtained under conditions different from real thermal vacuum facility and therefore should be subjected to additional experimental verification. Only in the last few years contamination effect on optical surfaces degradation has been considered with using empirical relations. Mirror reflective properties degradation leads to the increase of Solar Simulator errors. This ultimately has an adverse effect on S/C ground development, schedule and cost of thermal vacuum tests. Besides, the mirror maintenance in operable state becomes more expensive. The present paper is dedicated to the study of Solar Simulator collimation

  3. Motorized control for mirror mount apparatus

    DOEpatents

    Cutburth, Ronald W.

    1989-01-01

    A motorized control and automatic braking system for adjusting mirror mount apparatus is disclosed. The motor control includes a planetary gear arrangement to provide improved pitch adjustment capability while permitting a small packaged design. The motor control for mirror mount adjustment is suitable for laser beam propagation applications. The brake is a system of constant contact, floating detents which engage the planetary gear at selected between-teeth increments to stop rotation instantaneously when the drive motor stops.

  4. Anesthetic management of maternal Mirror syndrome.

    PubMed

    Tayler, E; DeSimone, C

    2014-11-01

    Mirror syndrome (Ballantyne syndrome, triple edema, maternal hydrops, pseudotoxemia) is a rarely diagnosed condition associated with pregnancy that can be life-threatening for both the mother and fetus. There is limited literature on its pathogenesis and anesthetic management, making prevention and treatment complex. The duration of pregnancy and severity of maternal or fetal presentation often determines outcome. We describe the anesthetic considerations of a morbidly obese parturient with Mirror syndrome. PMID:25066819

  5. Mirror therapy for phantom limb pain.

    PubMed

    Kim, Sae Young; Kim, Yun Young

    2012-10-01

    Phantom limb pain is a painful sensation that is perceived in a body part that no longer exists. To control this pain, many methods have been used such as medication, physical treatment, nerve block, neuromodulation, surgical treatment and mirror therapy. However, until now, there effects have been uncertain. We report the successful reduction of phantom limb pain using mirror therapy when other treatments initially failed to control the pain. PMID:23091690

  6. 49 CFR 571.111 - Standard No. 111; Rearview mirrors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... mirror that reflect images, excluding the mirror rim or mounting brackets. Unit magnification mirror... image of an object is equal to the angular height and width of the object when viewed directly at the... WHILE BUS IS MOVING. IMAGES IN SUCH MIRRORS DO NOT ACCURATELY SHOW ANOTHER VEHICLE'S LOCATION.”...

  7. 49 CFR 571.111 - Standard No. 111; Rearview mirrors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... mirror that reflect images, excluding the mirror rim or mounting brackets. Unit magnification mirror... image of an object is equal to the angular height and width of the object when viewed directly at the... WHILE BUS IS MOVING. IMAGES IN SUCH MIRRORS DO NOT ACCURATELY SHOW ANOTHER VEHICLE'S LOCATION.”...

  8. Ultra-precision grinding of chemically vapor deposited silicon carbide mirrors for synchrotron radiation

    SciTech Connect

    Namba, Yoshiharu

    1996-12-31

    Chemically vapor deposited silicon carbide (CVD-SiC) is the most important material of mirrors for high-brightness synchrotron radiation beamlines, though the material is too difficult to be machined. It takes quite a long time to polish SiC substrate to make mirrors. This paper intends to reduce the machining time to make CVD-SiC mirrors by using ultra-precision grinding technology. The CVD-SiC sample has been ground into 0.4nm rms in surface roughness by a resinoid-bonded diamond wheel and an ultra-precision surface grinder having a glass-ceramic spindle of extremely-low thermal expansion. The surface roughness of ground samples were measured with TOPO-3D and AFM. 88.7% reflectivity has been obtained on the ground CVD-SiC flat surface, measured with X-ray of 0.834 nm in wavelength at the grazing incident angle of 0.7--0.95 degree. The reflectivity depends upon the angle between the direction of incident beam and grinding marks on the sample. The relationship between the surface roughness and grinding conditions was also discussed.

  9. Test production of a mirror segment for the Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Oota, Tetsuji; Shinonaga, Hirohiko; Akutsu, Kotaro; Hashimoto, Yuichiro; Otsuka, Itaru; Iwasaki, Yasushi; Iye, Masanori; Yamashita, Takuya; Akitaya, Hiroshi; Suzuki, Ryuji

    2012-09-01

    The Thirty Meter Telescope (TMT) is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. This paper describes the progress of the test fabrication of an outermost mirror segment for the TMT as a joint R&D program between National Astronomical Observatory and Canon. A zero-expansion glass CLEARCERAM™ blank was polished by a computer-controlled small-tool polishing machine (CSSP, Canon) and its surface shape was measured by a touch-probe measuring machine(A-Ruler, Canon). Residuals of lower Zernike terms of the surface shape were 11 nmRMS, clearing the original specifications based on the structure function. There remains, however, a need to fulfill latest revised specifications. Possible solutions to improve and achieve the new specifications and a plan for revising the process for mass production are also described.

  10. Research on process technology of off-axis ellipsoid aspheric mirror

    NASA Astrophysics Data System (ADS)

    Liu, Dongmei; Ma, Ke; Jia, Zonghe

    2015-02-01

    In recent years, the off-axis aspheric surface is widely used in wide coverage and high-resolution space optical systems. In this paper, research on processing technology of high precision and high efficiency off-axis ellipsoid aspheric mirror was studied deeply. With the help of CNC milling and polishing machine, off-axis ellipsoid aspheric mirror with diameter of 58mm was developed, by optimizing the concentration of polish liquid, grinding size, machining direction and other process parameters, based on the disadvantage of traditional processing that off-axis aspheric is easy to generate edge splitting and secondary surface damage, a new processing method "vertical off-axis ellipsoid aspheric surface processing method" was put forward. This method not only ensures the accuracy of work piece of optical axis, surface accuracy and accuracy of the edge, but also reduces secondary surface damage, improves processing efficiency and achieves high precision and high efficiency processing of off-axis ellipsoid aspheric surface, which is conducive to mass production. Through the detection of off-axis ellipsoid aspheric mirror by Taylor Profiler , surface accuracy (PV value) is 0.1981μm, the aspheric surface finish is level II and the optical axis accuracy is 0.01mm that it meets the requirements.

  11. The Dizzying Depths of the Cylindrical Mirror

    NASA Astrophysics Data System (ADS)

    DeWeerd, Alan J.; Hill, S. Eric

    2005-02-01

    A typical introduction to geometrical optics treats plane and spherical mirrors. At first glance, it may be surprising that texts seldom mention the cylindrical mirror, except for the occasional reference to use in fun houses and to viewing anamorphic art.1,2 However, even a cursory treatment reveals its complexity. Holzberlein used an extended object to qualitatively illustrate that images are produced both before and behind a concave cylindrical mirror.3 He also speculated on how this extreme astigmatism results in an observer's dizziness. By considering a simple point object, we make a more detailed analysis of the cylindrical mirror and the dizziness it induces. First, we illustrate how rays from a point object reflect to form not one point image but two line images. Next, we describe how an observer perceives a likeness of the object. Finally, we suggest how confusing depth cues induce dizziness. Although we focus on the concave cylindrical mirror, the discussion is easy to generalize to the convex cylindrical mirror.

  12. Development of CFRP mirrors for space telescopes

    NASA Astrophysics Data System (ADS)

    Utsunomiya, Shin; Kamiya, Tomohiro; Shimizu, Ryuzo

    2013-09-01

    CFRP (Caron fiber reinforced plastics) have superior properties of high specific elasticity and low thermal expansion for satellite telescope structures. However, difficulties to achieve required surface accuracy and to ensure stability in orbit have discouraged CFRP application as main mirrors. We have developed ultra-light weight and high precision CFRP mirrors of sandwich structures composed of CFRP skins and CFRP cores using a replica technique. Shape accuracy of the demonstrated mirrors of 150 mm in diameter was 0.8 μm RMS (Root Mean Square) and surface roughness was 5 nm RMS as fabricated. Further optimization of fabrication process conditions to improve surface accuracy was studied using flat sandwich panels. Then surface accuracy of the flat CFRP sandwich panels of 150 mm square was improved to flatness of 0.2 μm RMS with surface roughness of 6 nm RMS. The surface accuracy vs. size of trial models indicated high possibility of fabrication of over 1m size mirrors with surface accuracy of 1μm. Feasibility of CFRP mirrors for low temperature applications was examined for JASMINE project as an example. Stability of surface accuracy of CFRP mirrors against temperature and moisture was discussed.

  13. Vibration damping for the Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Maly, Joseph R.; Yingling, Adam J.; Griffin, Steven F.; Agrawal, Brij N.; Cobb, Richard G.; Chambers, Trevor S.

    2012-09-01

    The Segmented Mirror Telescope (SMT) at the Naval Postgraduate School (NPS) in Monterey is a next-generation deployable telescope, featuring a 3-meter 6-segment primary mirror and advanced wavefront sensing and correction capabilities. In its stowed configuration, the SMT primary mirror segments collapse into a small volume; once on location, these segments open to the full 3-meter diameter. The segments must be very accurately aligned after deployment and the segment surfaces are actively controlled using numerous small, embedded actuators. The SMT employs a passive damping system to complement the actuators and mitigate the effects of low-frequency (<40 Hz) vibration modes of the primary mirror segments. Each of the six segments has three or more modes in this bandwidth, and resonant vibration excited by acoustics or small disturbances on the structure can result in phase mismatches between adjacent segments thereby degrading image quality. The damping system consists of two tuned mass dampers (TMDs) for each of the mirror segments. An adjustable TMD with passive magnetic damping was selected to minimize sensitivity to changes in temperature; both frequency and damping characteristics can be tuned for optimal vibration mitigation. Modal testing was performed with a laser vibrometry system to characterize the SMT segments with and without the TMDs. Objectives of this test were to determine operating deflection shapes of the mirror and to quantify segment edge displacements; relative alignment of λ/4 or better was desired. The TMDs attenuated the vibration amplitudes by 80% and reduced adjacent segment phase mismatches to acceptable levels.

  14. Evaluation of microfabricated deformable mirror systems

    NASA Astrophysics Data System (ADS)

    Cowan, William D.; Lee, Max K.; Bright, Victor M.; Welsh, Byron M.

    1998-09-01

    This paper presents recent result for aberration correction and beam steering experiments using polysilicon surface micromachined piston micromirror arrays. Microfabricated deformable mirrors offer a substantial cost reduction for adaptive optic systems. In addition to the reduced mirror cost, microfabricated mirrors typically require low control voltages, thus eliminating high voltage amplifiers. The greatly reduced cost per channel of adaptive optic systems employing microfabricated deformable mirrors promise high order aberration correction at low cost. Arrays of piston micromirrors with 128 active elements were tested. Mirror elements are on a 203 micrometers 12 by 12 square grid. The overall array size is 2.4 mm square. The arrays were fabricated in the commercially available DARPA supported MUMPs surface micromachining foundry process. The cost per mirror array in this prototyping process is less than 200 dollars. Experimental results are presented for a hybrid correcting element comprised of a lenslet array and piston micromirror array, and for a piston micromirror array only. Also presented is a novel digital deflection micromirror which requires no digital to analog converters, further reducing the cost of adaptive optics system.

  15. Development of Nanolaminate Thin Shell Mirrors

    NASA Astrophysics Data System (ADS)

    Hickey, Gregory S.; Lih, Shyh-Shiuh; Barbee, Troy W., Jr.

    2002-12-01

    The space science community has identified a need for ultra-light weight, large aperture optical systems that are capable of producing high-resolution images of low contrast. Current mirror technologies are limited due either to not being scalable to larger sizes at reasonable masses, or to lack of surface finish, dimensional stability in a space environment or long fabrication times. This paper will discuss the development of thin-shell, nano-laminate mirror substrates that are capable of being electro-actively figured. This technology has the potential to substantially reduce the cost of space based optics by allowing replication of ultra-lightweight primary mirrors from a master precision tool. Precision master tools have been shown to be used multiple times with repeatable surface quality results with less than one week fabrication times for the primary optical mirror substrate. Current development has developed a series of 0.25 and 0.5 meter spherical nanolaminate mirrors that are less than 0.5 kg/m2 areal density before electroactive components are mounted, and a target of less than 2.0 kg/m with control elements. This paper will provide an overview of nanolaminate materials for optical mirrors, modeling of their behavior under figure control and experiments conducted to validate precision control.

  16. Aspheric mirror measurement based on fringe reflection

    NASA Astrophysics Data System (ADS)

    Su, Xianyu; Tang, Yan; Liu, Yuankun; Zhang, Qican; Xiang, Liqun

    2009-05-01

    The aspheric mirror can correct aberrations and improve imaging quality of optical system . M oreover using such mirror can reduce the num ber of optical elem ents in an optical system and further reduce the weight and size of the system . In order to improve the accuracy of aspheric mirror fabrication, there are many methods used to m easure aspheric mirror. Am ong these methods, the most popular one is interferom etry which can m easure the surface with very high accuracy. However, interferom etry commonly requires com plicated and expensive assistant optics, and its m easurem ent range is limited. In order to measure aspheric mirror conveniently and effectively, we further evolve the well know n approaches of 'Phase M easuring Deflectom ety'(PM D) to measure such surface. In this study, we present a novel m ethod based on fringe reflection to m easure aspheric m irror. In the m easurem ent process, the screen and the cam era are m oved along the mirror optical axis, respectively. Using the phase information of the recording fringe patterns, for each cam era pixel, we can calculate the slope and coordinate of its corresponding point on the surface to be tested. By integrating, the absolute height of the tested surface can be reconstructed. Com pared with traditional PM D, this m ethod can m easure the absolute height of an aspheric m irror unam biguously and doesn't need com plex calibration.

  17. Compound taper milling machine

    NASA Technical Reports Server (NTRS)

    Campbell, N. R.

    1969-01-01

    Simple, inexpensive milling machine tapers panels from a common apex to a uniform height at panel edge regardless of the panel perimeter configuration. The machine consists of an adjustable angled beam upon which the milling tool moves back and forth above a rotatable table upon which the workpiece is held.

  18. Technique for Machining Glass

    NASA Technical Reports Server (NTRS)

    Rice, S. H.

    1982-01-01

    Process for machining glass with conventional carbide tools requires a small quantity of a lubricant for aluminum applied to area of glass to be machined. A carbide tool is then placed against workpiece with light pressure. Tool is raised periodically to clear work of glass dust and particles. Additional lubricant is applied as it is displaced.

  19. THE TEACHING MACHINE.

    ERIC Educational Resources Information Center

    KLEIN, CHARLES; WAYNE, ELLIS

    THE ROLE OF THE TEACHING MACHINE IS COMPARED WITH THE ROLE OF THE PROGRAMED TEXTBOOK. THE TEACHING MACHINE IS USED FOR INDIVIDUAL INSTRUCTION, CONTAINS AND PRESENTS PROGRAM CONTENT IN STEPS, PROVIDES A MEANS WHEREBY THE STUDENT MAY RESPOND TO THE PROGRAM, PROVIDES THE STUDENT WITH IMMEDIATE INFORMATION OF SOME KIND CONCERNING HIS RESPONSE THAT CAN…

  20. Simple Machines Made Simple.

    ERIC Educational Resources Information Center

    St. Andre, Ralph E.

    Simple machines have become a lost point of study in elementary schools as teachers continue to have more material to cover. This manual provides hands-on, cooperative learning activities for grades three through eight concerning the six simple machines: wheel and axle, inclined plane, screw, pulley, wedge, and lever. Most activities can be…

  1. Simple Machine Junk Cars

    ERIC Educational Resources Information Center

    Herald, Christine

    2010-01-01

    During the month of May, the author's eighth-grade physical science students study the six simple machines through hands-on activities, reading assignments, videos, and notes. At the end of the month, they can easily identify the six types of simple machine: inclined plane, wheel and axle, pulley, screw, wedge, and lever. To conclude this unit,…

  2. Friction-Testing Machine

    NASA Technical Reports Server (NTRS)

    Benz, F. J.; Dixon, D. S.; Shaw, R. C.

    1986-01-01

    Testing machine evaluates wear and ignition characteristics of materials in rubbing contact. Offers advantages over other laboratory methods of measuring wear because it simulates operating conditions under which material will actually be used. Machine used to determine wear characteristics, rank and select materials for service with such active oxidizers as oxygen, halogens, and oxides of nitrogen, measure wear characteristics, and determine coefficients of friction.

  3. An asymptotical machine

    NASA Astrophysics Data System (ADS)

    Cristallini, Achille

    2016-07-01

    A new and intriguing machine may be obtained replacing the moving pulley of a gun tackle with a fixed point in the rope. Its most important feature is the asymptotic efficiency. Here we obtain a satisfactory description of this machine by means of vector calculus and elementary trigonometry. The mathematical model has been compared with experimental data and briefly discussed.

  4. Machining heavy plastic sections

    NASA Technical Reports Server (NTRS)

    Stalkup, O. M.

    1967-01-01

    Machining technique produces consistently satisfactory plane-parallel optical surfaces for pressure windows, made of plexiglass, required to support a photographic study of liquid rocket combustion processes. The surfaces are machined and polished to the required tolerances and show no degradation from stress relaxation over periods as long as 6 months.

  5. Machine Translation Project

    NASA Technical Reports Server (NTRS)

    Bajis, Katie

    1993-01-01

    The characteristics and capabilities of existing machine translation systems were examined and procurement recommendations were developed. Four systems, SYSTRAN, GLOBALINK, PC TRANSLATOR, and STYLUS, were determined to meet the NASA requirements for a machine translation system. Initially, four language pairs were selected for implementation. These are Russian-English, French-English, German-English, and Japanese-English.

  6. Stirling machine operating experience

    SciTech Connect

    Ross, B.; Dudenhoefer, J.E.

    1994-09-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.

  7. BRITISH MOLDING MACHINE, PBQ AUTOMATIC COPE AND DRAG MOLDING MACHINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BRITISH MOLDING MACHINE, PBQ AUTOMATIC COPE AND DRAG MOLDING MACHINE MAKES BOTH MOLD HALVES INDIVIDUALLY WHICH ARE LATER ROTATED, ASSEMBLED, AND LOWERED TO POURING CONVEYORS BY ASSISTING MACHINES. - Southern Ductile Casting Company, Casting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  8. 14. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific Railroad Carlin Shops, view to north (90mm lens). - Southern Pacific Railroad, Carlin Shops, Roundhouse Machine Shop Extension, Foot of Sixth Street, Carlin, Elko County, NV

  9. Machine tool evaluation and machining operation development

    SciTech Connect

    Morris, T.O.; Kegg, R.

    1997-03-15

    The purpose of this CRADA was to support Cincinnati Milacron`s needs in fabricating precision components, from difficult to machine materials, while maintaining and enhancing the precision manufacturing skills of the Oak Ridge Complex. Oak Ridge and Cincinnati Milacron personnel worked in a team relationship wherein each contributed equally to the success of the program. Process characterization, control technologies, machine tool capabilities, and environmental issues were the primary focus areas. In general, Oak Ridge contributed a wider range of expertise in machine tool testing and monitoring, and environmental testing on machining fluids to the defined tasks while Cincinnati Milacron personnel provided equipment, operations-specific knowledge and shop-floor services to each task. Cincinnati Milacron was very pleased with the results of all of the CRADA tasks. However, some of the environmental tasks were not carried through to a desired completion due to an expanding realization of need as the work progressed. This expansion of the desired goals then exceeded the time length of the CRADA. Discussions are underway on continuing these tasks under either a Work for Others agreement or some alternate funding.

  10. Micro-machining.

    PubMed

    Brinksmeier, Ekkard; Preuss, Werner

    2012-08-28

    Manipulating bulk material at the atomic level is considered to be the domain of physics, chemistry and nanotechnology. However, precision engineering, especially micro-machining, has become a powerful tool for controlling the surface properties and sub-surface integrity of the optical, electronic and mechanical functional parts in a regime where continuum mechanics is left behind and the quantum nature of matter comes into play. The surprising subtlety of micro-machining results from the extraordinary precision of tools, machines and controls expanding into the nanometre range-a hundred times more precise than the wavelength of light. In this paper, we will outline the development of precision engineering, highlight modern achievements of ultra-precision machining and discuss the necessity of a deeper physical understanding of micro-machining. PMID:22802498

  11. Introduction to machine learning.

    PubMed

    Baştanlar, Yalin; Ozuysal, Mustafa

    2014-01-01

    The machine learning field, which can be briefly defined as enabling computers make successful predictions using past experiences, has exhibited an impressive development recently with the help of the rapid increase in the storage capacity and processing power of computers. Together with many other disciplines, machine learning methods have been widely employed in bioinformatics. The difficulties and cost of biological analyses have led to the development of sophisticated machine learning approaches for this application area. In this chapter, we first review the fundamental concepts of machine learning such as feature assessment, unsupervised versus supervised learning and types of classification. Then, we point out the main issues of designing machine learning experiments and their performance evaluation. Finally, we introduce some supervised learning methods. PMID:24272434

  12. Cryogenic silicon carbide mirrors for infrared astronomical telescopes: lessons learnt from AKARI for SPICA

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Kaneda, Hidehiro; Kawada, Mitsunobu; Enya, Keigo; Nakagawa, Takao

    2013-09-01

    Silicon carbide (SiC) has good thermal conductivity, high stiffness, and a relatively low specific density, all of which are advantageous to the application to telescopes operating at cryogenic temperatures. The first Japanese astronomical infrared space mission AKARI, which was launched in 2006 February and completed the second generation all-sky survey at 6 bands from mid- to far-infrared, employed a 700mm cryogenic telescope made of specially developed SiC. It was a sandwich-type of SiC composed of a lightweight porous core and a dense chemical vapor deposition (CVD) coat to decrease the specific density and facilitate machining for achieving the required surface figure accuracy. Measurements with an interferometer of 160-mm sample mirrors demonstrated that the AKARI mirror SiC had good thermal stability down to cryogenic temperatures (~6K), while the mirror support of the compact design became the primary source of the wave-front errors of the AKARI telescope. Taking the advantage of the heritage of the AKARI telescope development as well as ESA's Herschel telescope, we are planning the next infrared space mission SPICA (Space Infrared Telescope for Cosmology and Astrophysics) of a 3.2m cooled telescope in participation of ESA using SiC-based materials. In this presentation, we summarize the development of AKARI SiC telescope and present the development activities of the SPICA telescope from the point of view of SiC being as the mirror material for cryogenic space infrared telescopes.

  13. A Novel Microprocessor-Controlled High-Voltage Driver for Deformable Mirrors

    NASA Astrophysics Data System (ADS)

    Heuck, H.-M.; Buske, I.; Buschmann, U.; Krause, H.; Wittrock, U.

    Genetic algorithms have found widespread use in adaptive optics. One important advantage compared to the matrix inversion method is that it is not necessary to measure the wavefront of the optical beam on which the deformable mirror acts. Instead, any signal, that is monotonic increasing with the quality of the desired wavefront, is sufficient as a feedback signal. Often, this signal derives from a power-in-the-bucket measurement in the far-field of the beam. In coherent control of chemical reactions with temporally shaped femtosecond laser pulses the signal derives from the rate at which the desired chemical is produced. In our adaptive optics experiments we use micro-machined silicon membrane mirrors with up to 59 electrostatic actuators. We have developed a microprocessor-controlled highvoltage driver for up to 60 channels because we could not find a suitable driver on the market. The driver is a fully self-contained unit that only needs input power and communicates with a personal computer via a USB interface. It is especially suited for controlling adaptive mirrors with a genetic algorithm. The driver can store up to 100 voltage patterns, apply them sequentially to the mirror, store up to 4 feedback signals for each voltage pattern, and relay these feedback signals back to the host computer. We will discuss performance issues and tradeoffs like speed, bit resolution, and number of electrodes in our presentation.

  14. The mirror illusion: does proprioceptive drift go hand in hand with sense of agency?

    PubMed Central

    Tajima, Daisuke; Mizuno, Tota; Kume, Yuichiro; Yoshida, Takako

    2015-01-01

    Vection can be regarded as the illusion of “whole-body” position perception. In contrast, the mirror illusion is that of “body-part” position perception. When participants viewed their left hands in a mirror positioned along the midsaggital axis while moving both hands synchronously, they hardly noticed the spatial offset between the hand in the mirror and the obscured real right hand. This illusion encompasses two phenomena: proprioceptive drift and sense of agency. Proprioceptive drift represented a perceptual change in the position of the obscured hand relative to that of the hand in the mirror. Sense of agency referred to the participants' subjective sense of controlling body image as they would their own bodies. We examined the spatial offset between these two phenomena. Participants responded to a two-alternative forced choice (2AFC) question regarding the subjective position of their right hands and questionnaires regarding sense of agency at various positions of the right hand. We analyzed the 2AFC data using a support vector machine and compared its classification result and the questionnaire results. Our data analysis suggested that the two phenomena were observed in concentric space, but the estimated range of the proprioceptive drift was slightly narrower than the range of agency. Although this outcome can be attributed to differences in measurement or analysis, to our knowledge, this is the first report to suggest that proprioceptive drift and sense of agency are concentric and almost overlap. PMID:25774145

  15. Performance of a magnetic driven tip-tilt mirror

    NASA Astrophysics Data System (ADS)

    Farinato, Jacopo; Esposito, Simone; Marchetti, Enrico; Ragazzoni, Roberto; Bruns, Donald G.

    1997-03-01

    ThermoTrex Corporation has designed and built a prototype of the fast steering mirror to be used for image motion control in the TNG adaptive optics system. The principal characteristic of this mirror is the use of voice coil actuators whose positions are controlled with closed loops based on capacitive sensors. Here we report the main features of the mirror assembly and laboratory measurements done to characterize the mirror behavior. The Bode diagram of the mirror is reported and discussed.

  16. Optical Performance Modeling of FUSE Telescope Mirror

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Ohl, Raymond G.; Friedman, Scott D.; Moos, H. Warren

    2000-01-01

    We describe the Metrology Data Processor (METDAT), the Optical Surface Analysis Code (OSAC), and their application to the image evaluation of the Far Ultraviolet Spectroscopic Explorer (FUSE) mirrors. The FUSE instrument - designed and developed by the Johns Hopkins University and launched in June 1999 is an astrophysics satellite which provides high resolution spectra (lambda/Delta(lambda) = 20,000 - 25,000) in the wavelength region from 90.5 to 118.7 nm The FUSE instrument is comprised of four co-aligned, normal incidence, off-axis parabolic mirrors, four Rowland circle spectrograph channels with holographic gratings, and delay line microchannel plate detectors. The OSAC code provides a comprehensive analysis of optical system performance, including the effects of optical surface misalignments, low spatial frequency deformations described by discrete polynomial terms, mid- and high-spatial frequency deformations (surface roughness), and diffraction due to the finite size of the aperture. Both normal incidence (traditionally infrared, visible, and near ultraviolet mirror systems) and grazing incidence (x-ray mirror systems) systems can be analyzed. The code also properly accounts for reflectance losses on the mirror surfaces. Low frequency surface errors are described in OSAC by using Zernike polynomials for normal incidence mirrors and Legendre-Fourier polynomials for grazing incidence mirrors. The scatter analysis of the mirror is based on scalar scatter theory. The program accepts simple autocovariance (ACV) function models or power spectral density (PSD) models derived from mirror surface metrology data as input to the scatter calculation. The end product of the program is a user-defined pixel array containing the system Point Spread Function (PSF). The METDAT routine is used in conjunction with the OSAC program. This code reads in laboratory metrology data in a normalized format. The code then fits the data using Zernike polynomials for normal incidence

  17. Magnetic mirror fusion-fission early history and applicability to other systems

    SciTech Connect

    Moir, R

    2009-08-24

    In the mid 1970s to mid 1980s the mirror program was stuck with a concept, the Standard Mirror that was Q {approx} 1 where Q=P{sub fusion}/P{sub injection}. Heroic efforts were put into hybridizing thinking added energy and fuel sales would make a commercial product. At the same time the tokamak was thought to allow ignition and ultrahigh Q values of 20 or even higher. There was an effort to use neutral beams to drive the tokamak just like the mirror machines were driven in which case the Q value plunged to a few, however this was thought to be achievable decades earlier than the high Q versions. Meanwhile current drive and other features of the tokamak have seen the projected Q values come down to the range of 10. Meanwhile the mirror program got Q enhancement into high gear and various tandem mirrors projected Q values up towards 10 and with advanced features over 10 with axi-symmetric magnets (See R. F. Post papers), however the experimental program is all but non-existent. Meanwhile, the gas dynamic trap mirror system which is present day state-of-the-art can with low risk produce Q of {approx}0.1 useful for a low risk, low cost neutron source for materials development useful for the development of materials for all fusion concepts (see Simonen white paper: 'A Physics-Based Strategy to Develop a Mirror Fusion-Fission Hybrid' and D.D. Ryutov, 'Axisymmetric MHD-stable mirror as a neutron source and a driver for a fusion-fission hybrid'). Many early hybrid designs with multi-disciplinary teams were carried out in great detail for the mirror system with its axi-symmetric blanket modules. It is recognized that most of these designs are adaptable to tokamak or inertial fusion geometry. When Q is low (1 to 2) economics gives a large economic penalty for high recirculating power. These early studies covered the three design types: Power production, fuel production and waste burning. All three had their place but power production fell away because every study showed

  18. Dual-use bimorph deformable mirrors

    NASA Astrophysics Data System (ADS)

    Griffith, M. S.; Laycock, L. C.; Bagshaw, J. M.; Rowe, D.

    2005-11-01

    Adaptive Optics (AO) is a critical underpinning technology for future optical countermeasures, laser delivery, target illumination and imaging systems. It measures and compensates for optical distortion caused by transmission through the atmosphere, resulting in the ability to deploy smaller lasers and identify targets at greater ranges. AO is also well established in ground based astronomy, and is finding applications in free space optical communications and ophthalmology. One of the key components in an AO system is the wavefront modifier, which acts on the incoming or outgoing beam to counter the effects of the atmosphere. BAE SYSTEMS ATC is developing multi-element Deformable Bimorph Mirrors (DBMs) for such applications. A traditional bimorph deformable mirror uses a set of edge electrodes outside the active area in order to meet the required boundary conditions for the active aperture. This inflicts a significant penalty in terms of bandwidth, which is inversely proportional to the square of the full mirror diameter. We have devised a number of novel mounting arrangements that reduce dead space and thus provide a much improved trade-off between bandwidth and stroke. These schemes include a novel method for providing vertical displacement at the periphery of the aperture, a method for providing a continuous compliant support underneath the bimorph mirror, and a method for providing a three point support underneath the bimorph. In all three cases, there is no requirement for edge electrodes to provide the boundary conditions, resulting in devices of much higher bandwidth. The target is to broaden the use of these types of mirror beyond the current limits of either low order/low bandwidth, to address the high order, high bandwidth systems required by long range, horizontal path applications. This paper will discuss the different mirror designs, and present experimental results for the most recently assembled mirrors.

  19. Integration of Mirror Design with Suspension System using NASA's New Mirror Modeling Software

    NASA Technical Reports Server (NTRS)

    Arnold,William R., Sr.; Bevan, Ryan M.; Stahl, Philip

    2013-01-01

    Advances in mirror fabrication are making very large space based telescopes possible. In many applications, only monolithic mirrors can meet the performance requirements. The existing and near-term planned heavy launch vehicles place a premium on lowest possible mass, and then available payload shroud sizes limit near term designs to 4 meter class mirrors. Practical 8 meter class and beyond designs could encourage planners to include larger shrouds, if it can be proven that such mirrors can be manufactured. These two factors, lower mass and larger mirrors, present the classic optimization problem. There is a practical upper limit to how large of a mirror can be supported by a purely kinematic mount system handling both operational and launch loads. This paper shows how the suspension system and mirror blank need to be designed simultaneously. We will also explore the concepts of auxiliary support systems which act only during launch and disengage on orbit. We will define required characteristics of these systems and show how they can substantially reduce the mirror mass.

  20. Integration of Mirror Design with Suspension System Using NASA's New Mirror Modeling Software

    NASA Technical Reports Server (NTRS)

    Arnold, William R., Sr.; Bevan, Ryan M.; Stahl, H. Philip

    2013-01-01

    Advances in mirror fabrication are making very large space based telescopes possible. In many applications, only monolithic mirrors can meet the performance requirements. The existing and near-term planned heavy launch vehicles place a premium on lowest possible mass, and then available payload shroud sizes limit near term designs to 4 meter class mirrors. Practical 8 meter class and beyond designs could encourage planners to include larger shrouds, if it can be proven that such mirrors can be manufactured. These two factors, lower mass and larger mirrors, present the classic optimization problem. There is a practical upper limit to how large of a mirror can be supported by a purely kinematic mount system handling both operational and launch loads. This paper shows how the suspension system and mirror blank need to be designed simultaneously. We will also explore the concepts of auxiliary support systems which act only during launch and disengage on orbit. We will define required characteristics of these systems and show how they can substantially reduce the mirror mass.

  1. Integration of mirror design with suspension system using NASA's new mirror modeling software

    NASA Astrophysics Data System (ADS)

    Arnold, William R.; Bevan, Ryan M.; Stahl, H. Philip

    2013-09-01

    Advances in mirror fabrication are making very large space based telescopes possible. In many applications, only monolithic mirrors can meet the performance requirements. The existing and near-term planned heavy launch vehicles place a premium on lowest possible mass, and then available payload shroud sizes limit near term designs to 4 meter class mirrors. Practical 8 meter class and beyond designs could encourage planners to include larger shrouds, if it can be proven that such mirrors can be manufactured. These two factors, lower mass and larger mirrors, present the classic optimization problem. There is a practical upper limit to how large of a mirror can be supported by a purely kinematic mount system handling both operational and launch loads. This paper shows how the suspension system and mirror blank need to be designed simultaneously. We will also explore the concepts of auxiliary support systems which act only during launch and disengage on orbit. We will define required characteristics of these systems and show how they can substantially reduce the mirror mass.

  2. Is that me in the mirror? Depersonalisation modulates tactile mirroring mechanisms.

    PubMed

    Adler, Julia; Schabinger, Nadine; Michal, Matthias; Beutel, Manfred E; Gillmeister, Helge

    2016-05-01

    Our sense of self is thought to develop through sensory-motor contingencies provided, not only by observing one's own body, but also by mirroring interactions with others. This suggests that there is a strong link between mirroring mechanisms and the bodily self. The present study tested whether this link is expressed at early, implicit stages of the mirroring process or at later, more cognitive stages. We also provide, to the best of our knowledge, the first demonstration of how inter-individual differences in our sense of bodily self may affect mirroring mechanisms. We used somatosensory event-related potentials (SEPs) to investigate the temporal dynamics of mirroring highly self-related information (viewed touch on one's own face) compared to other-related information (viewed touch on a stranger's face), in individuals with low and high levels of depersonalisation, a mental condition characterised by feeling detached or estranged from one's self and body. For the low-depersonalisation group, mirroring for self-related events (P45) preceded mirroring for other-related events (N80). At later stages (P200), mirroring was stronger for other-related than self-related events. This shows that early, implicit and later, more cognitive processes play different relative roles in mirroring self- and other-related bodily events. Critically, mirroring differed in the high-depersonalisation group, specifically for self-related events. An absence of early, implicit mirroring for self-related events over P45 suggests that the associated processes may be the neural correlates of the disembodiment experienced in depersonalisation. A lack of differential mirroring for self- and other-related events over P200 may reflect compensatory mechanisms that redress deficiencies in mirroring at earlier stages, which may break down to give rise to symptoms of depersonalisation. Alternatively, or in addition, they may represent an attenuation of processes related to self-other distinction

  3. The Basic Anaesthesia Machine

    PubMed Central

    Gurudatt, CL

    2013-01-01

    After WTG Morton's first public demonstration in 1846 of use of ether as an anaesthetic agent, for many years anaesthesiologists did not require a machine to deliver anaesthesia to the patients. After the introduction of oxygen and nitrous oxide in the form of compressed gases in cylinders, there was a necessity for mounting these cylinders on a metal frame. This stimulated many people to attempt to construct the anaesthesia machine. HEG Boyle in the year 1917 modified the Gwathmey's machine and this became popular as Boyle anaesthesia machine. Though a lot of changes have been made for the original Boyle machine still the basic structure remains the same. All the subsequent changes which have been brought are mainly to improve the safety of the patients. Knowing the details of the basic machine will make the trainee to understand the additional improvements. It is also important for every practicing anaesthesiologist to have a thorough knowledge of the basic anaesthesia machine for safe conduct of anaesthesia. PMID:24249876

  4. The basic anaesthesia machine.

    PubMed

    Gurudatt, Cl

    2013-09-01

    After WTG Morton's first public demonstration in 1846 of use of ether as an anaesthetic agent, for many years anaesthesiologists did not require a machine to deliver anaesthesia to the patients. After the introduction of oxygen and nitrous oxide in the form of compressed gases in cylinders, there was a necessity for mounting these cylinders on a metal frame. This stimulated many people to attempt to construct the anaesthesia machine. HEG Boyle in the year 1917 modified the Gwathmey's machine and this became popular as Boyle anaesthesia machine. Though a lot of changes have been made for the original Boyle machine still the basic structure remains the same. All the subsequent changes which have been brought are mainly to improve the safety of the patients. Knowing the details of the basic machine will make the trainee to understand the additional improvements. It is also important for every practicing anaesthesiologist to have a thorough knowledge of the basic anaesthesia machine for safe conduct of anaesthesia. PMID:24249876

  5. Machine Learning and Radiology

    PubMed Central

    Wang, Shijun; Summers, Ronald M.

    2012-01-01

    In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. PMID:22465077

  6. Flute instability and the associated radial transport in the tandem mirror with a divertor mirror cell

    SciTech Connect

    Katanuma, I.; Yagi, K.; Haraguchi, Y.; Ichioka, N.; Masaki, S.; Ichimura, M.; Imai, T.

    2010-11-15

    The flute instability and the associated radial transport are investigated in the tandem mirror with a divertor mirror cell (the GAMMA10 A-divertor) with help of computer simulation, where GAMMA10 is introduced [Inutake et al., Phys. Rev. Lett. 55, 939 (1985)]. The basic equations used in the simulation were derived on the assumption of an axisymmetric magnetic field. So the high plasma pressure in a nonaxisymmetric minimum-B anchor mirror cell, which is important for the flute mode stability, is taken into account by redefining the specific volume of a magnetic field line. It is found that the flute modes are stabilized by the minimum-B magnetic field even with a divertor mirror although its stabilizing effects are weaker than that without the divertor mirror. The flute instability enhances the radial transport by intermittently repeating the growing up and down of the Fourier amplitude of the flute instability in time.

  7. DNA-based machines.

    PubMed

    Wang, Fuan; Willner, Bilha; Willner, Itamar

    2014-01-01

    The base sequence in nucleic acids encodes substantial structural and functional information into the biopolymer. This encoded information provides the basis for the tailoring and assembly of DNA machines. A DNA machine is defined as a molecular device that exhibits the following fundamental features. (1) It performs a fuel-driven mechanical process that mimics macroscopic machines. (2) The mechanical process requires an energy input, "fuel." (3) The mechanical operation is accompanied by an energy consumption process that leads to "waste products." (4) The cyclic operation of the DNA devices, involves the use of "fuel" and "anti-fuel" ingredients. A variety of DNA-based machines are described, including the construction of "tweezers," "walkers," "robots," "cranes," "transporters," "springs," "gears," and interlocked cyclic DNA structures acting as reconfigurable catenanes, rotaxanes, and rotors. Different "fuels", such as nucleic acid strands, pH (H⁺/OH⁻), metal ions, and light, are used to trigger the mechanical functions of the DNA devices. The operation of the devices in solution and on surfaces is described, and a variety of optical, electrical, and photoelectrochemical methods to follow the operations of the DNA machines are presented. We further address the possible applications of DNA machines and the future perspectives of molecular DNA devices. These include the application of DNA machines as functional structures for the construction of logic gates and computing, for the programmed organization of metallic nanoparticle structures and the control of plasmonic properties, and for controlling chemical transformations by DNA machines. We further discuss the future applications of DNA machines for intracellular sensing, controlling intracellular metabolic pathways, and the use of the functional nanostructures for drug delivery and medical applications. PMID:24647836

  8. Tape-Drive Based Plasma Mirror

    SciTech Connect

    Sokollik, Thomas; Shiraishi, Satomi; Osterhoff, Jens; Evans, Eugene; Gonsalves, Anthony; Nakamura, Kei; vanTilborg, Jeroen; Lin, Chen; Toth, Csaba; Leemans, Wim

    2011-07-22

    We present experimental results on a tape-drive based plasma mirror which could be used for a compact coupling of a laser beam into a staged laser driven electron accelerator. This novel kind of plasma mirror is suitable for high repetition rates and for high number of laser shots. In order to design a compact, staged laser plasma based accelerator or collider [1], the coupling of the laser beam into the different stages represents one of the key issues. To limit the spatial foot print and thus to realize a high overall acceleration gradient, a concept has to be found which realizes this in-coupling within a few centimeters (cf. Fig 1). The fluence of the laser pulse several centimeters away from the acceleration stage (focus) exceeds the damage threshold of any available mirror coating. Therefore, in reference [2] a plasma mirror was suggested for this purpose. We present experiments on a tape-drive based plasma mirror which could be used to reflect the focused laser beam into the acceleration stage. Plasma mirrors composed of antireflection coated glass substrates are usually used to improve the temporal laser contrast of laser pulses by several orders of magnitudes [3,4]. This is particularly important for laser interaction with solid matter, such as ion acceleration [5,6] and high harmonic generation on surfaces [7]. Therefore, the laser pulse is weekly focused onto a substrate. The main pulse generates a plasma and is reflected at the critical surface, whereas the low intensity pre-pulse (mainly the Amplified Spontaneous Emission pedestal) will be transmitted through the substrate before the mirror has been triggered. Several publications [3,4] demonstrate a conservation of the spatial beam quality and a reflectivity of about 70 %. The drawback of this technique is the limited repetition rate since for every shot a fresh surface has to be provided. In the past years several novel approaches for high repetition rate plasma mirrors have been developed [2, 8

  9. Quantum Boltzmann Machine

    NASA Astrophysics Data System (ADS)

    Kulchytskyy, Bohdan; Andriyash, Evgeny; Amin, Mohammed; Melko, Roger

    The field of machine learning has been revolutionized by the recent improvements in the training of deep networks. Their architecture is based on a set of stacked layers of simpler modules. One of the most successful building blocks, known as a restricted Boltzmann machine, is an energetic model based on the classical Ising Hamiltonian. In our work, we investigate the benefits of quantum effects on the learning capacity of Boltzmann machines by extending its underlying Hamiltonian with a transverse field. For this purpose, we employ exact and stochastic training procedures on data sets with physical origins.

  10. OPTICAM machine design

    NASA Astrophysics Data System (ADS)

    Liedes, Jyrki T.

    1992-01-01

    Rank Pneumo has worked with the Center of Optics Manufacturing to design a multiple-axis flexible machining center for spherical lens fabrication. The OPTICAM/SM prototype machine has been developed in cooperation with the Center's Manufacturing Advisory Board. The SM will generate, fine grind, pre-polish, and center a spherical lens surface in one setup sequence. Unique features of the design incorporate machine resident metrology to provide RQM (Real-time Quality Management) and closed-loop feedback control that corrects for lens thickness, diameter, and centering error. SPC (Statistical Process Control) software can compensate for process drift and QA data collection is provided without additional labor.

  11. Machine Tool Software

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

  12. MEMS deformable mirrors for astronomical adaptive optics

    NASA Astrophysics Data System (ADS)

    Cornelissen, S. A.; Hartzell, A. L.; Stewart, J. B.; Bifano, T. G.; Bierden, P. A.

    2010-07-01

    We report on the development of high actuator count, micro-electromechanical (MEMS) deformable mirrors designed for high order wavefront correction in ground and space-based astronomical adaptive optics instruments. The design of these polysilicon, surface-micromachined MEMS deformable mirrors builds on technology that has been used extensively to correct for ocular aberrations in retinal imaging systems and for compensation of atmospheric turbulence in free-space laser communication. These light-weight, low power deformable mirrors have an active aperture of up to 25.2mm consisting of a thin silicon membrane mirror supported by an array of 140 to 4092 electrostatic actuators which exhibit no hysteresis and have sub-nanometer repeatability making them well suited for open-loop control applications such as Multi-Object Adaptive Optics (MOAO). The continuous membrane deformable mirrors, coated with a highly reflective metal film, are capable of up to 6μm of stroke, have a surface finish of <10nm RMS with a fill factor of 99.8%. Presented in this paper are device characteristics and performance test results, as well as reliability test data and device lifetime predictions that show that trillions of actuator cycles can be achieved without failures.

  13. Design of off-axis PIAACMC mirrors

    NASA Astrophysics Data System (ADS)

    Pluzhnik, Eugene; Guyon, Olivier; Belikov, Ruslan; Bendek, Eduardo

    2015-09-01

    The Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) provides an efficient way to control diffraction propagation effects caused by the central obstruction/segmented mirrors of the telescope. PIAACMC can be optimized in a way that takes into account both chromatic diffraction effects caused by the telescope obstructed aperture and tip/tilt sensitivity of the coronagraph. As a result, unlike classic PIAA, the PIAACMC mirror shapes are often slightly asymmetric even for an on-axis configuration and require more care in calculating off-axis shapes when an off-axis configuration is preferred. A method to design off-axis PIAA mirror shapes given an on-axis mirror design is presented. The algorithm is based on geometrical ray tracing and is able to calculate off-axis PIAA mirror shapes for an arbitrary geometry of the input and output beams. The method is demonstrated using the third generation PIAACMC design for WFIRST-AFTA telescope. Geometrical optics design issues related to the off-axis diffraction propagation effects are also discussed.

  14. Demonstration of Flying Mirror with Improved Efficiency

    SciTech Connect

    Pirozhkov, Alexander S.; Kando, Masaki; Fukuda, Yuji; Chen Liming; Daito, Izuru; Ogura, Koichi; Homma, Takayuki; Hayashi, Yukio; Kotaki, Hideyuki; Sagisaka, Akito; Mori, Michiaki; Koga, James K.; Kawachi, Tetsuya; Kiriyama, Hiromitsu; Okada, Hajime; Kawase, Keigo; Kameshima, Takashi; Nishimori, Nobuyuki; Kimura, Toyoaki; Tajima, Toshiki

    2009-07-25

    A strongly nonlinear wake wave driven by an intense laser pulse can act as a partially reflecting relativistic mirror (the flying mirror)[S. V. Bulanov, et al., Bulletin of the Lebedev Physics Institute, No. 6, 9 (1991); S. V. Bulanov, et al., Phys. Rev. Lett. 91, 085001 (2003)]. Upon reflection from such mirror, a counter-propagating optical-frequency laser pulse is directly converted into high-frequency radiation, with a frequency multiplication factor approx4gamma{sup 2}(the double Doppler effect). We present the results of recent experiment in which the photon number in the reflected radiation was at least several thousand times larger than in our proof-of-principle experiment [M. Kando, et al., Phys. Rev. Lett. 99, 135001 (2007); A. S. Pirozhkov, et al., Phys. Plasmas 14, 123106 (2007)]. The flying mirror holds promise of generating intense coherent ultrashort XUV and x-ray pulses that inherit their temporal shape and polarization from the original optical-frequency (laser) pulses. Furthermore, the reflected radiation bears important information about the reflecting wake wave itself, which can be used for its diagnostics.

  15. Microinstabilities in the Gasdynamic Mirror Propulsion System

    NASA Technical Reports Server (NTRS)

    Emrich, William

    2005-01-01

    The gasdynamic mirror has been proposed as a concept which could form the basis of a highly efficient fusion rocket engine. Gasdynamic mirrors differ from most other mirror type plasma confinement schemes in that they have much larger aspect ratios and operate at somewhat higher plasma densities. There are several types of instabilities which are known to plague mirror type confinement schemes. These instabilities fall into two general classes. One class of instability is the Magnetohdrodynamic or MHD instability which induces gross distortions in the plasma geometry. The other class of instability is the "loss cone" microinstability which leads to general plasma turbulence. The "loss cone" microinstability is caused by velocity space asymmetries resulting from the loss of plasma having constituent particle velocities within the angle of the magnetic mirror "loss cone." These instabilities generally manifest themselves in high temperature, moderately dense plasmas. The present study indicates that a GDM configured as a rocket engine might operate in a plasma regine where microinstabilities could potentially be significant.

  16. Microinstabilities in the Gasdynamic Mirror Propulsion System

    NASA Technical Reports Server (NTRS)

    Emrich, William

    2005-01-01

    The gasdynamic mirror has been proposed as a concept which could form the basis of a highly efficient fusion rocket engine. Gasdynamic mirrors differ from most other mirror type plasma confinement schemes in that they have much larger aspect ratios and operate at somewhat higher plasma densities. There are several types of instabilities which are known to plague mirror type confinement schemes. These instabilities fall into two general classes. One class of instability is the Magnetohydrodynamic or MHD instability which induces gross distortions in the plasma geometry. The other class of instability is the "loss cone" microinstability which leads to general plasma turbulence. The "loss cone" microinstability is caused by velocity space asymmetries resulting from the loss of plasma having constituent particle velocities within the angle of the magnetic mirror "loss cone." These instabilities generally manifest themselves in high temperature, moderately dense plasmas. The present study indicates that a GDM configured as a rocket engine might operate in a plasma regime where microinstabilities could potentially be significant.

  17. Advances in Tandem Mirror fusion power reactors

    SciTech Connect

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

    1986-05-20

    The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and several advanced reactor concepts including the wall-stabilized reactor and the field-reversed mirror. With a novel compact end plug scheme employing octopole stabilization, MINIMARS is expressly designed for short construction times, factory-built modules, and a small (600 MWe) but economic reactor size. We have also configured the design for low radioactive afterheat and inherent/passive safety under LOCA/LOFA conditions, thereby obviating the need for expensive engineered safety systems. In contrast to the complex and expensive double-quadrupole end-cell of the MARS reactor, the compact octopole end-cell of MINIMARS enables ignition to be achieved with much shorter central cell lengths and considerably improves the economy of scale for small (approx.250 to 600 MWe) tandem mirror reactors. Finally, we examine the prospects for realizing the ultimate potential of the tandem mirror with regard to both innovative configurations and novel neutron energy conversion schemes, and stress that advanced fuel applications could exploit its unique reactor features.

  18. Thermal performance of the ATST secondary mirror

    NASA Astrophysics Data System (ADS)

    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.

  19. Performance evaluations of the ATST secondary mirror

    NASA Astrophysics Data System (ADS)

    Cho, Myung K.; DeVries, Joseph; Hansen, Eric

    2007-09-01

    The Advanced Technology Solar Telescope (ATST) has a 4.24m off-axis primary mirror designed to deliver diffraction-limited 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 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 PCFRINGE TM for the optical analysis. We examined extensive heat transfer simulation cases and their results are discussed. The goal of this study is to evaluate the optical performances of M2 using thermal models and mechanical models. Thermal responses from the models enable us to manipulate time dependent thermal loadings to synthesize the operational environment for the design and development of TMS.

  20. Rollable Thin-Shell Nanolaminate Mirrors

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Lih, Shyh-Shiuh; Barbee, Troy, Jr.

    2003-01-01

    A class of lightweight, deployable, thin-shell, curved mirrors with built-in precise-shape-control actuators is being developed for high-resolution scientific imaging. This technology incorporates a combination of advanced design concepts in actuation and membrane optics that, heretofore, have been considered as separate innovations. These mirrors are conceived to be stowed compactly in a launch shroud and transported aboard spacecraft, then deployed in outer space to required precise shapes at much larger dimensions (diameters of the order of meters or tens of meters). A typical shell rollable mirror structure would include: (1) a flexible single- or multiple-layer face sheet that would include an integrated reflective surface layer that would constitute the mirror; (2) structural supports in the form of stiffeners made of a shape-memory alloy (SMA); and (3) piezoelectric actuators. The actuators, together with an electronic control subsystem, would implement a concept of hierarchical distributed control, in which (1) the SMA actuators would be used for global shape control and would generate the large deformations needed for the deployment process and (2) the piezoelectric actuators would generate smaller deformations and would be used primarily to effect fine local control of the shape of the mirror.