Method for laser welding ultra-thin metal foils

DOEpatents

Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

1996-01-01

A method for simultaneously cutting and welding ultra-thin foils having a thickness of less than 0.002 inches wherein two ultra-thin films are stacked and clamped together. A pulsed laser such as of the Neodymium: YAG type is provided and the beam of the laser is directed onto the stacked films to cut a channel through the films. The laser is moved relative to the stacked foils to cut the stacked foils at successive locations and to form a plurality of connected weld beads to form a continuous weld.

Simultaneous laser cutting and welding of metal foil to edge of a plate

DOEpatents

Pernicka, John C.; Benson, David K.; Tracy, C. Edwin

1996-01-01

A method of welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads.

Piezoelectric characterization of Pb(Zr,Ti)O3 thin films deposited on metal foil substrates by dip coating

NASA Astrophysics Data System (ADS)

Hida, Hirotaka; Hamamura, Tomohiro; Nishi, Takahito; Tan, Goon; Umegaki, Toshihito; Kanno, Isaku

2017-10-01

We fabricated the piezoelectric bimorphs composed of Pb(Zr,Ti)O3 (PZT) thin films on metal foil substrates. To efficiently inexpensively manufacture piezoelectric bimorphs with high flexibility, 1.2-µm-thick PZT thin films were directly deposited on both surfaces of 10- and 20-µm-thick bare stainless-steel (SS) foil substrates by dip coating with a sol-gel solution. We confirmed that the PZT thin films deposited on the SS foil substrates at 500 °C or above have polycrystalline perovskite structures and the measured relative dielectric constant and dielectric loss were 323-420 and 0.12-0.17, respectively. The PZT bimorphs were demonstrated by comparing the displacements of the cantilever specimens driven by single- and double-side PZT thin films on the SS foil substrates under the same applied voltage. We characterized the piezoelectric properties of the PZT bimorphs and the calculated their piezoelectric coefficient |e 31,f| to be 0.3-0.7 C/m2.

Scanning electron microscopy imaging of dislocations in bulk materials, using electron channeling contrast.

PubMed

Crimp, Martin A

2006-05-01

The imaging and characterization of dislocations is commonly carried out by thin foil transmission electron microscopy (TEM) using diffraction contrast imaging. However, the thin foil approach is limited by difficult sample preparation, thin foil artifacts, relatively small viewable areas, and constraints on carrying out in situ studies. Electron channeling imaging of electron channeling contrast imaging (ECCI) offers an alternative approach for imaging crystalline defects, including dislocations. Because ECCI is carried out with field emission gun scanning electron microscope (FEG-SEM) using bulk specimens, many of the limitations of TEM thin foil analysis are overcome. This paper outlines the development of electron channeling patterns and channeling imaging to the current state of the art. The experimental parameters and set up necessary to carry out routine channeling imaging are reviewed. A number of examples that illustrate some of the advantages of ECCI over thin foil TEM are presented along with a discussion of some of the limitations on carrying out channeling contrast analysis of defect structures. Copyright (c) 2006 Wiley-Liss, Inc.

Conducting-polymer-driven actively shaped propellers and screws

NASA Astrophysics Data System (ADS)

Madden, John D.; Schmid, Bryan; Lafontaine, Serge R.; Madden, Peter G. A.; Hover, Franz S.; McLetchie, Karl; Hunter, Ian W.

2003-07-01

Conducting polymer actuators are employed to create actively shaped hydrodynamic foils. The active foils are designed to allow control over camber, much like the ailerons of an airplane wing. Control of camber promises to enable variable thrust in propellers and screws, increased maneuverability, and improved stealth. The design and fabrication of the active foils are presented, the forces are measured and operation is demonstrated both in still air and water. The foils have a "wing" span of 240 mm, and an average chord length (width) of 70 mm. The trailing 30 mm of the foil is composed of a thin polypyrrole actuator that curls chordwise to achieve variable camber. The actuator consists of two 30 μm thick sheets of hexafluorophosphate doped polypyrrole separated from each other by a gel electrolyte. A polymer layer encapsulates the entire structure. Potentials are applied between the polymer layers to induce reversible bending by approximately 35 degrees, and generating forces of 0.15 N. These forces and displacements are expected to enable operation in water at flow rates of > 1 m/s and ~ 30 m/s in air.

Simultaneous laser cutting and welding of metal foil to edge of a plate

DOEpatents

Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

1996-03-19

A method is described for welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads. 7 figs.

A heater made from graphite composite material for potential deicing application

NASA Technical Reports Server (NTRS)

Hung, C. C.; Stahl, M.; Stahl, M.; Stahl, M.

1986-01-01

A surface heater was developed using a graphite fiber-epoxy composite as the heating element. This heater can be thin, highly electrically and thermally conductive, and can conform to an irregular surface. Therefore it may be used in an aircraft's thermal deicing system to quickly and uniformly heat the aircraft surface. One-ply of unidirectional graphite fiber-epoxy composite was laminated between two plies of fiber glass-epoxy composite, with nickel foil contacting the end portions of the composite and partly exposed beyond the composites for electrical contact. The model heater used brominated P-100 fibers from Amoco. The fiber's electrical resistivity, thermal conductivity and density were 50 micro ohms per centimeter, 270 W/m-K and 2.30 gm/cubic cm, respectively. The electricity was found to penetrate through the composite in the transverse direction to make an acceptably low foil-composite contact resistance. When conducting current, the heater temperature increase reached 50 percent of the steady state value within 20 sec. There was no overheating at the ends of the heater provided there was no water corrosion. If the foil-composite bonding failed during storage, liquid water exposure was found to oxidize the foil. Such bonding failure may be avoided if perforated nickel foil is used, so that the composite plies can bond to each other through the perforated holes and therefore lock the foil in place.

Calibration of a thin metal foil for infrared imaging video bolometer to estimate the spatial variation of thermal diffusivity using a photo-thermal technique.

PubMed

Pandya, Shwetang N; Peterson, Byron J; Sano, Ryuichi; Mukai, Kiyofumi; Drapiko, Evgeny A; Alekseyev, Andrey G; Akiyama, Tsuyoshi; Itomi, Muneji; Watanabe, Takashi

2014-05-01

A thin metal foil is used as a broad band radiation absorber for the InfraRed imaging Video Bolometer (IRVB), which is a vital diagnostic for studying three-dimensional radiation structures from high temperature plasmas in the Large Helical Device. The two-dimensional (2D) heat diffusion equation of the foil needs to be solved numerically to estimate the radiation falling on the foil through a pinhole geometry. The thermal, physical, and optical properties of the metal foil are among the inputs to the code besides the spatiotemporal variation of temperature, for reliable estimation of the exhaust power from the plasma illuminating the foil. The foil being very thin and of considerable size, non-uniformities in these properties need to be determined by suitable calibration procedures. The graphite spray used for increasing the surface emissivity also contributes to a change in the thermal properties. This paper discusses the application of the thermographic technique for determining the spatial variation of the effective in-plane thermal diffusivity of the thin metal foil and graphite composite. The paper also discusses the advantages of this technique in the light of limitations and drawbacks presented by other calibration techniques being practiced currently. The technique is initially applied to a material of known thickness and thermal properties for validation and finally to thin foils of gold and platinum both with two different thicknesses. It is observed that the effect of the graphite layer on the estimation of the thermal diffusivity becomes more pronounced for thinner foils and the measured values are approximately 2.5-3 times lower than the literature values. It is also observed that the percentage reduction in thermal diffusivity due to the coating is lower for high thermal diffusivity materials such as gold. This fact may also explain, albeit partially, the higher sensitivity of the platinum foil as compared to gold.

Calibration of a thin metal foil for infrared imaging video bolometer to estimate the spatial variation of thermal diffusivity using a photo-thermal technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandya, Shwetang N., E-mail: pandya.shwetang@LHD.nifs.ac.jp; Sano, Ryuichi; Peterson, Byron J.

A thin metal foil is used as a broad band radiation absorber for the InfraRed imaging Video Bolometer (IRVB), which is a vital diagnostic for studying three-dimensional radiation structures from high temperature plasmas in the Large Helical Device. The two-dimensional (2D) heat diffusion equation of the foil needs to be solved numerically to estimate the radiation falling on the foil through a pinhole geometry. The thermal, physical, and optical properties of the metal foil are among the inputs to the code besides the spatiotemporal variation of temperature, for reliable estimation of the exhaust power from the plasma illuminating the foil.more » The foil being very thin and of considerable size, non-uniformities in these properties need to be determined by suitable calibration procedures. The graphite spray used for increasing the surface emissivity also contributes to a change in the thermal properties. This paper discusses the application of the thermographic technique for determining the spatial variation of the effective in-plane thermal diffusivity of the thin metal foil and graphite composite. The paper also discusses the advantages of this technique in the light of limitations and drawbacks presented by other calibration techniques being practiced currently. The technique is initially applied to a material of known thickness and thermal properties for validation and finally to thin foils of gold and platinum both with two different thicknesses. It is observed that the effect of the graphite layer on the estimation of the thermal diffusivity becomes more pronounced for thinner foils and the measured values are approximately 2.5–3 times lower than the literature values. It is also observed that the percentage reduction in thermal diffusivity due to the coating is lower for high thermal diffusivity materials such as gold. This fact may also explain, albeit partially, the higher sensitivity of the platinum foil as compared to gold.« less

Preparation and comparative testing of advanced diamond-like carbon foils for tandem accelerators and time-of-flight spectrometers

NASA Astrophysics Data System (ADS)

Liechtenstein, V. Kh.; Ivkova, T. M.; Olshanski, E. D.; Baranov, A. M.; Repnow, R.; Hellborg, R.; Weller, R. A.; Wirth, H. L.

1999-12-01

The sputter preparation technique for thin diamond-like carbon (DLC) foils, advantageously used for ion-beam stripping and timing in accelerator experiments, has been optimized to improve the quality and the performance of the foils. Irradiation lifetimes of 5 μg/cm 2 DLC foils prepared by this technique have been compared with those for foils of approximately the same thickness, prepared by laser plasma ablation and for ethylene cracked foils when bombarded by 11 MeV Cu - - and Au --ion beams of ˜1 μA beam current at the Heidelberg MP-tandem. Standard carbon arc-evaporated foils were used as references. In these experiments, DLC stripper foils appeared to have a mean lifetime approximately two times longer than ethylene-cracked foils regardless of ion species, and compared favorably with foils prepared by laser ablation method. All these foils lasted at least, 10 times longer than standard carbon foils, when irradiated in the MP terminal. Approximately, the same improvement factor was confirmed with 3 μg/cm 2 DLC stripper foils irradiated with 2.3 MeV Ni-beams at the Pelletron accelerator in Lund. Unlike standard carbon foils, most of the advanced lifetime foils exhibited thinning during long irradiation, under clean vacuum. This suggests that sputtering of the foil by the heavy-ion beam might be a dominant process, responsible for the observed failure of these long-lived strippers. Along with specifically corrugated self-supporting DLC beam strippers, we succeeded in the fabrication of very smooth and ultra thin (˜0.5 μg/cm 2) DLC foils, mounted on grids and used as start foils for the ToF spectrometers applied in ion beam analysis.

Method of forming a thin unbacked metal foil

DOEpatents

Duchane, David V.; Barthell, Barry L.

1984-01-01

In a method of forming a thin (<2 .mu.m) unbacked metal foil having a desired curviplanar shape, a soluble polymeric film, preferably comprising polyvinyl alcohol, is formed on a supporting structure having a shape that defines the desired shape of the foil product. A layer of metal foil is deposited onto one side of the soluble film, preferably by vacuum vapor deposition. The metallized film is then immersed in a suitable solvent to dissolve the film and thereby leave the metal foil as an unbacked metal foil element mounted on the supporting structure. Aluminum foils less than 0.2 .mu.m (2,000 .ANG.) thick and having an areal density of less than 54 .mu.g/cm.sup.2 have been obtained.

Heat Transfer in High Temperature Multilayer Insulation

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Miller, Steve D.; Cunnington, George R.

2007-01-01

High temperature multilayer insulations have been investigated as an effective component of thermal-protection systems for atmospheric re-entry of reusable launch vehicles. Heat transfer in multilayer insulations consisting of thin, gold-coated, ceramic reflective foils and Saffil(TradeMark) fibrous insulation spacers was studied both numerically and experimentally. A finite volume numerical thermal model using combined conduction (gaseous and solid) and radiation in porous media was developed. A two-flux model with anisotropic scattering was used for radiation heat transfer in the fibrous insulation spacers between the reflective foils. The thermal model was validated by comparison with effective thermal conductivity measurements in an apparatus based on ASTM standard C201. Measurements were performed at environmental pressures in the range from 1x10(exp -4) to 760 torr over the temperature range from 300 to 1300 K. Four multilayer samples with nominal densities of 48 kg/cu m were tested. The first sample was 13.3 mm thick and had four evenly spaced reflective foils. The other three samples were 26.6 mm thick and utilized either one, two, or four reflective foils, located near the hot boundary with nominal foil spacing of 1.7 mm. The validated thermal model was then used to study relevant design parameters, such as reflective foil spacing and location in the stack-up and coating of one or both sides of foils.

Shock compression response of highly reactive Ni + Al multilayered thin foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, Sean C.; Thadhani, Naresh N., E-mail: naresh.thadhani@mse.gatech.edu

2016-03-07

The shock-compression response of Ni + Al multilayered thin foils is investigated using laser-accelerated thin-foil plate-impact experiments over the pressure range of 2 to 11 GPa. The foils contain alternating Ni and Al layers (parallel but not flat) of nominally 50 nm bilayer spacing. The goal is to determine the equation of state and shock-induced reactivity of these highly reactive fully dense thin-foil materials. The laser-accelerated thin-foil impact set-up involved combined use of photon-doppler-velocimetry to monitor the acceleration and impact velocity of an aluminum flyer, and VISAR interferometry was used to monitor the back free-surface velocity of the impacted Ni + Al multilayered target. The shock-compressionmore » response of the Ni + Al target foils was determined using experimentally measured parameters and impedance matching approach, with error bars identified considering systematic and experimental errors. Meso-scale CTH shock simulations were performed using real imported microstructures of the cross-sections of the multilayered Ni + Al foils to compute the Hugoniot response (assuming no reaction) for correlation with their experimentally determined equation of state. It was observed that at particle velocities below ∼150 m/s, the experimentally determined equation of state trend matches the CTH-predicted inert response and is consistent with the observed unreacted state of the recovered Ni + Al target foils from this velocity regime. At higher particle velocities, the experimentally determined equation of state deviates from the CTH-predicted inert response. A complete and self-sustained reaction is also seen in targets recovered from experiments performed at these higher particle velocities. The deviation in the measured equation of state, to higher shock speeds and expanded volumes, combined with the observation of complete reaction in the recovered multilayered foils, confirmed via microstructure characterization, is indicative of the occurrence of shock-induced chemical reaction occurring in the time-scale of the high-pressure state. TEM characterization of recovered shock-compressed (unreacted) Ni + Al multilayered foils exhibits distinct features of constituent mixing revealing jetted layers and inter-mixed regions. These features were primarily observed in the proximity of the undulations present in the alternating layers of the Ni + Al starting foils, suggesting the important role of such instabilities in promoting shock-induced intermetallic-forming reactions in the fully dense highly exothermic multilayered thin foils.« less

Approximating the near-edge mass absorption coefficients for Ni using an ultra-thin bimetal foil

DOE PAGES

Alkire, Randall W.

2016-11-01

In an effort to improve the characteristics of a fluorescing metal-foil-based beam position monitor, a new bimetal ultra-thin (0.98/0.67 µm) Ti–Ni foil was introduced to replace an existing single-element ultra-thin 0.5 µm thick Cr foil. During characterization it was determined that absorption measurements on the bimetal foil could be used to fit the Ni mass absorption coefficients accurately in the vicinity of the NiKedge. Comparison with experimental results from the literature demonstrated that the fitting procedure produced coefficients with uncertainties of the order of ±1%. Once determined, these fit coefficients allowed the thickness of an independently mounted 8 µm thickmore » Ni foil to be computed from absorption measurements instead of relying on a tool-based measurement of the foil thickness. Using the 8 µm thick foil, a continuous map of Ni mass absorption coefficients was produced at 1 eV resolution throughout the near-edge region. Lastly, this high-resolution map marks a significant improvement over the existing NIST XCOM or FFAST database mass absorption coefficients, which have estimated errors of 10–20% for the near-edge region.« less

X-ray optics made from thin plastic foils

NASA Astrophysics Data System (ADS)

Schnopper, Herbert W.; Silver, Eric H.; Ingram, Russell H.; Christensen, Finn E.; Hussain, Ahsen M.; Barbera, Marco; Romaine, Suzanne E.; Collura, Alfonso; Kenter, Almus T.; Bandler, Simon; Murray, Stephen S.

1999-09-01

New design concepts and materials can be used to produce very lightweight, thin foil approximations, to Wolter I and other x-ray optics. Structures are designed around a central hub and spacers that connect one spoked wheels. Figure defining, thin pins span the distance between the wheels. Thin, metal coated or multilayered, plastic foils can be formed into cones, cylinders or spirals for x-ray telescopes or lenses. Imaging and spectroscopic data obtained with x- ray lenses are presented and they indicate that a 60 cm diameter, 4.65 m focal length x-ray telescope can have a half power diameter of < 2 arcmin.

Spot-Welding Gun With Pivoting Twin-Collet Assembly

NASA Technical Reports Server (NTRS)

Nguyen, Francis; Simpson, Gareth; Hoult, William S.

1996-01-01

Modified spot-welding gun includes pivoting twin-collet assembly that holds two spot-welding electrodes. Designed to weld highly conductive (30 percent gold) brazing-alloy foils to thin nickel alloy workpieces; also suitable for other spot-welding applications compatible with two-electrode configuration.

Radiation pressure acceleration of corrugated thin foils by Gaussian and super-Gaussian beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adusumilli, K.; Goyal, D.; Tripathi, V. K.

Rayleigh-Taylor instability of radiation pressure accelerated ultrathin foils by laser having Gaussian and super-Gaussian intensity distribution is investigated using a single fluid code. The foil is allowed to have ring shaped surface ripples. The radiation pressure force on such a foil is non-uniform with finite transverse component F{sub r}; F{sub r} varies periodically with r. Subsequently, the ripple grows as the foil moves ahead along z. With a Gaussian beam, the foil acquires an overall curvature due to non-uniformity in radiation pressure and gets thinner. In the process, the ripple perturbation is considerably washed off. With super-Gaussian beam, the ripplemore » is found to be more strongly washed out. In order to avoid transmission of the laser through the thinning foil, a criterion on the foil thickness is obtained.« less

Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martini, R., E-mail: roberto.martini@imec.be; imec, Kapeldreef 75, 3001 Leuven; Kepa, J.

2014-10-27

We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process.more » A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.« less

Pu-Zr alloy for high-temperature foil-type fuel

DOEpatents

McCuaig, Franklin D.

1977-01-01

A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron reflux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

Pu-ZR Alloy high-temperature activation-measurement foil

DOEpatents

McCuaig, Franklin D.

1977-08-02

A nuclear reactor fuel alloy consists essentially of from slightly greater than 7 to about 4 w/o zirconium, balance plutonium, and is characterized in that the alloy is castable and is rollable to thin foils. A preferred embodiment of about 7 w/o zirconium, balance plutonium, has a melting point substantially above the melting point of plutonium, is rollable to foils as thin as 0.0005 inch thick, and is compatible with cladding material when repeatedly cycled to temperatures above 650.degree. C. Neutron flux densities across a reactor core can be determined with a high-temperature activation-measurement foil which consists of a fuel alloy foil core sandwiched and sealed between two cladding material jackets, the fuel alloy foil core being a 7 w/o zirconium, plutonium foil which is from 0.005 to 0.0005 inch thick.

Analytic Modeling of the Hydrodynamic, Thermal, and Structural Behavior of Foil Thrust Bearings

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; DellaCorte, Christopher; Prahl, Joseph M.

2005-01-01

A simulation and modeling effort is conducted on gas foil thrust bearings. A foil bearing is a self acting hydrodynamic device capable of separating stationary and rotating components of rotating machinery by a film of air or other gaseous lubricant. Although simple in appearance these bearings have proven to be complicated devices in analysis. They are sensitive to fluid structure interaction, use a compressible gas as a lubricant, may not be in the fully continuum range of fluid mechanics, and operate in the range where viscous heat generation is significant. These factors provide a challenge to the simulation and modeling task. The Reynolds equation with the addition of Knudsen number effects due to thin film thicknesses is used to simulate the hydrodynamics. The energy equation is manipulated to simulate the temperature field of the lubricant film and combined with the ideal gas relationship, provides density field input to the Reynolds equation. Heat transfer between the lubricant and the surroundings is also modeled. The structural deformations of the bearing are modeled with a single partial differential equation. The equation models the top foil as a thin, bending dominated membrane whose deflections are governed by the biharmonic equation. A linear superposition of hydrodynamic load and compliant foundation reaction is included. The stiffness of the compliant foundation is modeled as a distributed stiffness that supports the top foil. The system of governing equations is solved numerically by a computer program written in the Mathematica computing environment. Representative calculations and comparisons with experimental results are included for a generation I gas foil thrust bearing.

Experimental study of the spatial distributions of relativistic electron beams reflected and refracted by a thin foil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serov, A. V., E-mail: serov@x4u.lebedev.ru; Mamonov, I. A.

2016-08-15

Photographs of cross sections of an electron beam scattered from thin foils have been obtained on a dosimetric film. The procession of images makes it possible to obtain the spatial distribution of particles both reflected from a foil and passed through it. The spatial distribution of electrons incident on aluminum, copper, and lead foils, as well as on bimetallic foils composed of aluminum and lead layers and of aluminum and copper layers, has been measured. The effect of the material and thickness of the foil, as well as of the angle between the initial beam trajectory and the target plane,more » on the spatial distribution of electrons has been studied. The effect of the sequence of the metal layers in bimetallic foils on the distribution of beams has been analyzed. A 7.4-MeV microtron has been used as a source of electrons.« less

Edge-on dislocation loop in anisotropic hcp zirconium thin foil

NASA Astrophysics Data System (ADS)

Wu, Wenwang; Xia, Re; Qian, Guian; Xu, Shucai; Zhang, Jinhuan

2015-10-01

Edge-on dislocation loops with 〈 a 〉 -type and 〈 c 〉 -type of Burgers vectors can be formed on prismatic or basel habit planes of hexagonal close-packed (hcp) zirconium alloys during in-situ ion irradiation and neutron irradiation experiments. In this work, an anisotropic image stress method was employed to analyze the free surface effects of dislocation loops within hcp Zr thin foils. Calculation results demonstrate that image stress has a remarkable effect on the distortion fields of dislocation loops within infinite medium, and the image energy becomes remarkable when dislocation loops are situated close to the free surfaces. Moreover, image forces of the 1 / 2 〈 0001 〉 (0001) dislocation loop within (0001) thin foil is much stronger than that of the 1 / 3 〈 11 2 bar 0 〉 (11 2 bar 0) dislocation loop within (11 2 bar 0) thin foil of identical geometrical configurations. Finally, image stress effect on the physical behaviors of loops during in-situ ion irradiation experiments is discussed.

Role of target material in proton acceleration from thin foils irradiated by ultrashort laser pulses.

PubMed

Tayyab, M; Bagchi, S; Ramakrishna, B; Mandal, T; Upadhyay, A; Ramis, R; Chakera, J A; Naik, P A; Gupta, P D

2014-08-01

We report on the proton acceleration studies from thin metallic foils of varying atomic number (Z) and thicknesses, investigated using a 45 fs, 10 TW Ti:sapphire laser system. An optimum foil thickness was observed for efficient proton acceleration for our laser conditions, dictated by the laser ASE prepulse and hot electron propagation behavior inside the material. The hydrodynamic simulations for ASE prepulse support the experimental observation. The observed maximum proton energy at different thicknesses for a given element is in good agreement with the reported scaling laws. The results with foils of different atomic number Z suggest that a judicious choice of the foil material can enhance the proton acceleration efficiency, resulting into higher proton energy.

Conformable wearable systems comprising organic electronics on foil for well being and healthcare (presentation video)

NASA Astrophysics Data System (ADS)

de Kok, Margreet M.

2014-10-01

Integration of electronics into materials and objects that have not been functionalized with electronics before, open up extensive possibilities to support mankind. By adding intelligence and/or operating power to materials in close skin contact like clothing, furniture or bandages the health of people can be monitored or even improved. Foil based electronics are interesting components to be integrated as they are thin, large area and cost effective available components Our developed technology of printed electronic structures to which components are reliably bonded, fulfills the promise. We have integrated these components into textiles and built wearable encapsulated products with foil based electronics. Foil components with organic and inorganic LEDs are interconnected and laminated onto electronic textiles by using conductive adhesives to bond the contact pads of the component to conductive yarns in the textile. Modelling and reliability testing under dynamic circumstances provided important insights in order to optimise the technology. The design of the interconnection and choice of conductive adhesive / underfill and lamination contributed to the durability of the system. Transition zones from laminated foil to textile are engineered to withstand dynamic use. As an example of a product, we have realized an electronic wristband that is encapsulated in rubber and has a number of sensor functionalities integrated on stretchable electronic circuits based on Cu and Ag. The encapsulation with silicone or polyurethanes was performed such, that charging and sensor/skin contacts are possible while simultaneously protecting the electronics from mechanical and environmental stresses.

n-Type Conductivity of Cu2O Thin Film Prepared in Basic Aqueous Solution Under Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Ursu, Daniel; Miclau, Nicolae; Miclau, Marinela

2018-03-01

We report for the first time in situ hydrothermal synthesis of n-type Cu2O thin film using strong alkaline solution. The use of copper foil as substrate and precursor material, low synthesis temperature and short reaction time represent the arguments of a new, simple, inexpensive and high field synthesis method for the preparation of n-type Cu2O thin film. The donor concentration of n-type Cu2O thin film obtained at 2 h of reaction time has increased two orders of magnitude than previous reported values. We have demonstrated n-type conduction in Cu2O thin film prepared in strong alkaline solution, in the contradiction with the previous works. Based on experimental results, the synthesis mechanism and the origin of n-type photo-responsive behavior of Cu2O thin film were discussed. We have proposed that the unexpected n-type character could be explained by H doping of Cu2O thin film in during of the hydrothermal synthesis that caused the p-to-n conductivity-type conversion. Also, this work raises new questions about the origin of n-type conduction in Cu2O thin film, the influence of the synthesis method on the nature of the intrinsic defects and the electrical conduction behavior.

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tin-coated lead foil capsules for wine bottles... Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one or both sides with a thin layer...

Producing Foils From Direct Cast Titanium Alloy Strip

NASA Technical Reports Server (NTRS)

Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

1996-01-01

This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

Influence of sulfurization temperature on Cu2ZnSnS4 absorber layer on flexible titanium substrates for thin film solar cells

NASA Astrophysics Data System (ADS)

Gokcen Buldu, Dilara; Cantas, Ayten; Turkoglu, Fulya; Gulsah Akca, Fatime; Meric, Ece; Ozdemir, Mehtap; Tarhan, Enver; Ozyuzer, Lutfi; Aygun, Gulnur

2018-02-01

In this study, the effect of sulfurization temperature on the morphology, composition and structure of Cu2ZnSnS4 (CZTS) thin films grown on titanium (Ti) substrates has been investigated. Since Ti foils are flexible, they were preferred as a substrate. As a result of their flexibility, they allow large area manufacturing and roll-to-roll processes. To understand the effects of sulfurization temperature on the CZTS formation on Ti foils, CZTS films fabricated with various sulfurization temperatures were investigated with several analyses including x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy and Raman scattering. XRD measurements showed a sharp and intense peak coming from the (112) planes of the kesterite type lattice structure (KS), which is strong evidence for good crystallinity. The surface morphologies of our thin films were investigated using SEM. Electron dispersive spectroscopy was also used for the compositional analysis of the thin films. According to these analysis, it is observed that Ti foils were suitable as substrates for the growth of CZTS thin films with desired properties and the sulfurization temperature plays a crucial role for producing good quality CZTS thin films on Ti foil substrates.

Method of accurate thickness measurement of boron carbide coating on copper foil

DOEpatents

Lacy, Jeffrey L.; Regmi, Murari

2017-11-07

A method is disclosed of measuring the thickness of a thin coating on a substrate comprising dissolving the coating and substrate in a reagent and using the post-dissolution concentration of the coating in the reagent to calculate an effective thickness of the coating. The preferred method includes measuring non-conducting films on flexible and rough substrates, but other kinds of thin films can be measure by matching a reliable film-substrate dissolution technique. One preferred method includes determining the thickness of Boron Carbide films deposited on copper foil. The preferred method uses a standard technique known as inductively coupled plasma optical emission spectroscopy (ICPOES) to measure boron concentration in a liquid sample prepared by dissolving boron carbide films and the Copper substrates, preferably using a chemical etch known as ceric ammonium nitrate (CAN). Measured boron concentration values can then be calculated.

High temperature insulation materials for reradiative thermal protection systems

NASA Technical Reports Server (NTRS)

Hughes, T. A.

1972-01-01

Results are presented of a two year program to evaluate packaged thermal insulations for use under a metallic radiative TPS of a shuttle orbiter vehicle. Evaluations demonstrated their survival for up to 100 mission reuse cycles under shuttle acoustic and thermal loads with peak temperatures of 1000 F, 1800 F, 2000 F, 2200 F and 2500 F. The specimens were composed of low density refractory fiber felts, packaged in thin gage metal foils. In addition, studies were conducted on the venting requirements of the packages, salt spray resistance of the metal foils, and the thermal conductivity of many of the insulations as a function of temperature and ambient air pressure. Data is also presented on the radiant energy transport through insulations, and back-scattering coefficients were experimentally determined as a function of source temperature.

Transferable and flexible thin film devices for engineering applications

NASA Astrophysics Data System (ADS)

Mutyala, Madhu Santosh K.; Zhou, Jingzhou; Li, Xiaochun

2014-05-01

Thin film devices can be of significance for manufacturing, energy conversion systems, solid state electronics, wireless applications, etc. However, these thin film sensors/devices are normally fabricated on rigid silicon substrates, thus neither flexible nor transferrable for engineering applications. This paper reports an innovative approach to transfer polyimide (PI) embedded thin film devices, which were fabricated on glass, to thin metal foils. Thin film thermocouples (TFTCs) were fabricated on a thin PI film, which was spin coated and cured on a glass substrate. Another layer of PI film was then spin coated again on TFTC/PI and cured to obtain the embedded TFTCs. Assisted by oxygen plasma surface coarsening of the PI film on the glass substrate, the PI embedded TFTC was successfully transferred from the glass substrate to a flexible copper foil. To demonstrate the functionality of the flexible embedded thin film sensors, they were transferred to the sonotrode tip of an ultrasonic metal welding machine for in situ process monitoring. The dynamic temperatures near the sonotrode tip were effectively measured under various ultrasonic vibration amplitudes. This technique of transferring polymer embedded electronic devices onto metal foils yield great potentials for numerous engineering applications.

Temperature measurements at material interfaces with thin-foil gauges

NASA Astrophysics Data System (ADS)

Morley, Mike; Chapman, David; Proud, William

2009-06-01

Measurements of shock heating are important in determining Equations of State that incorporate entropic effects. The use of thin-foil nickel gauges to measure shock heating in material was proposed by Rosenberg et al. in the 1980s. This research investigates the use of such commercial thin-foil gauges at interfaces between materials of different thermal and shock properties. The technique requires analysis of the resistance changes of the gauge which is a function of both temperature and stress. The response of manganin gauges to shock loading is well understood, and was used to calibrate for the piezoresistive effect in nickel. Results are presented for a variety of well-characterised materials and the applicability of the proposed method discussed.

Temperature Measurements at Material Interfaces with Thin-Foil Gauges

NASA Astrophysics Data System (ADS)

Morley, Mike J.; Chapman, David J.; Proud, William G.

2009-12-01

Measurements of shock heating are important in determining Equations of State that incorporate entropic effects. The use of thin-foil nickel gauges to measure shock heating in material was proposed by Rosenberg et al. in the 1980s. This research investigates the use of such commercial thin-foil gauges at interfaces between materials of different thermal and shock properties. The technique requires analysis of the resistance changes of the gauge which is a function of both temperature and stress. The response of manganin gauges to shock loading is well understood, and was used to calibrate for the piezoresistive effect in nickel. Results are presented for a variety of well-characterised materials and the applicability of the proposed method discussed.

Effect of Substrate Compliance on Measuring Delamination Properties of Elastic Thin Foil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.

Through the analysis of a model problem, a thin elastic plate bonded to an elastic foundation, we address several issues related to the miniature bulge test for measuring the energy-release rate associated with the interfacial fracture of a bimaterial system, where one of the constituents is a thin foil. These issues include the effect of the substrate compliance on the interpretation of the energy release rate, interfacial strength, and the identification of the boundary of the deforming bulge or the location of the interfacial crack front. The analysis done also suggests a way for measuring the so-called foundation modulus, whichmore » characterizes the property of the substrate. An experimental example, a stainless steel thin foil bonded to an aluminum substrate through hot-isostatic-pressing (HIP), is used to illustrate and highlight some of the conclusions of the model analysis.« less

Effect of Substrate Compliance on Measuring Delamination Properties of Elastic Thin Foil

DOE PAGES

Liu, C.

2018-03-20

Through the analysis of a model problem, a thin elastic plate bonded to an elastic foundation, we address several issues related to the miniature bulge test for measuring the energy-release rate associated with the interfacial fracture of a bimaterial system, where one of the constituents is a thin foil. These issues include the effect of the substrate compliance on the interpretation of the energy release rate, interfacial strength, and the identification of the boundary of the deforming bulge or the location of the interfacial crack front. The analysis done also suggests a way for measuring the so-called foundation modulus, whichmore » characterizes the property of the substrate. An experimental example, a stainless steel thin foil bonded to an aluminum substrate through hot-isostatic-pressing (HIP), is used to illustrate and highlight some of the conclusions of the model analysis.« less

Design of a medium size x-ray mirror module based on thin glass foils

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Pareschi, Giovanni

2016-07-01

The hot slumping glass technology for X-ray mirror is under development and in the last years the results have been improved. Nustar is the first X-ray telescope based on slumped glass foils and it benefit is the low cost compared to the direct polishing of glass. With the slumping technique it is possible to maintain the glass mass to low values with respect to the direct polishing, but in general the angular resolution is worst. A further technique based on glass is the cold shaping of foils. The improved capabilities of manufacturing thin glass foils, pushed by the industrial application for screens, open new possibilities for X-ray mirror. The increase in strength of thin tempered glasses, the reduction of thickness errors and the good roughness of flat foils are potentially great advantages. In this paper a design of a mediumsize X-ray mirror module is analysed. It is based on integration of glass foils, stacked directly on a supporting structure that is part of the X-ray telescope using stiffening ribs as spacer between foils. The alignment of each stack is performed directly into the integration machine avoiding the necessity of the alignment of different stacked modules. A typical module (glass optic and metallic structure) provides an effective area of 10 cm2/kg at 1 keV (with a mass of about 50- 100 kg and a focal length of 10 m).

High-performance lithium-ion batteries with 1.5 μm thin copper nanowire foil as a current collector

NASA Astrophysics Data System (ADS)

Chu, Hsun-Chen; Tuan, Hsing-Yu

2017-04-01

Cu Foil, a thin sheet of Cu, is the common anode current collector in commercial lithium ion batteries (LIBs) which accounts for ∼ 10 wt% of the total cell weight. However, thickness reduction of LIB-based Cu foils below 6 μm has been limited by the incapability of conventional rolling annealing or electrodeposition process. We here report a new type of Cu foil, so called Cu nanowire foil (CuNW foil), for use as an LIB anode current collector. We fabricate Cu NW foils by rolling press Cu nanowire fabric to reduce the thickness down to ∼1.5 μm with an areal weight down to ∼1.2 mg cm-2 and a density approximately 96% to that of bulk Cu. The rough surface and porous structure of CuNW foil enable better wetting and adhering properties of graphite slurry on foil. In full cell examination, a cell of a areal capacity of 3 mAh cm-2 exhibits 83.6% capacity retention for 600 cycles at 0.6 C that meets the standard specification of most commercial LIBs. As a proof-of-concept of demonstration, we fabricate a 700 mA pouch-type battery implemented with graphite-Cu NWs foil anodes to serve as energy supply to operate electronic devices.

Scattering effects in passive foil focusing of ion beams

DOE PAGES

Yuen, Albert; Lund, Steven M.; Barnard, John J.; ...

2015-09-11

A stack of thin, closely spaced conducting foils has been investigated by Lund et al. [ Phys. Rev. ST Accel. Beams 16, 044202 (2013)] as a passive focusing lens for intense ion beams. The foils mitigate space-charge defocusing forces to enable the beam self-magnetic field to focus. In this study, we analyze possible degradation of focusing due to scattering of beam ions resulting from finite foil thickness using an envelope model and numerical simulations with the particle-in-cell code WARP. Ranges of kinetic energy where scattering effects are sufficient to destroy passive focusing are quantified. The scheme may be utilized tomore » focus protons produced in intense laser-solid accelerator schemes. The spot size of an initially collimated 30 MeV proton beam with initial rms radius 200 μm, perveance Q=1.8×10 -2, and initial transverse emittance ϵ x,rms=0.87 mm mrad propagating through a stack of 6.4 μm thick foils, spaced 100 μm apart, gives a 127.5 μm spot with scattering and a 81.0 μm spot without scattering, illustrating the importance of including scattering effects.« less

Collodion-reinforcement and plasma-cleaning of target foils

NASA Astrophysics Data System (ADS)

Stoner, John O.

2002-03-01

The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed.

Time-resolved K α spectroscopy measurements of hot-electron equilibration dynamics in thin-foil solid targets: collisional and collective effects

NASA Astrophysics Data System (ADS)

Nilson, P. M.; Solodov, A. A.; Davies, J. R.; Theobald, W.; Mileham, C.; Stoeckl, C.; Begishev, I. A.; Zuegel, J. D.; Froula, D. H.; Betti, R.; Meyerhofer, D. D.

2015-11-01

Time-resolved K α spectroscopy measurements from high-intensity laser interactions with thin-foil solid targets are reviewed. Thin Cu foils were irradiated with 1-10 J, 1 ps pulses at focused intensities from 1018 to 1019 W cm-2. The experimental data show K α -emission pulse widths from 3 to 6 ps, increasing with laser intensity. The time-resolved K α -emission data are compared to a hot-electron transport and K α -production model that includes collisional electron-energy coupling, resistive heating, and electromagnetic field effects. The experimental data show good agreement with the model when a reduced ponderomotive scaling is used to describe the initial mean hot-electron energy over the relevant intensity range.

Developing NanoFoil-Heated Thin-Film Thermal Battery

DTIC Science & Technology

2013-09-01

buffer discs (in gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat...of the fuse strip with a Microtherm disc. Cathode Electrolyte Anode Microtherm Heat paper NanoFoil Buffer Agilent 34970A 606.5 Nichrome wire Maccor...gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat loss

Development of CIGS2 Thin Films on Ultralightweight Flexible Large Area Foil Sunstrates

NASA Technical Reports Server (NTRS)

Dhere, Neelkanth G.; Gade, Vivek S.; Kadam, Ankur A.; Jahagirdar, Anant H.; Kulkarni, Sachin S.; Bet, Sachin M.

2005-01-01

The development of thin film solar cells is aimed at reducing the costs for photovoltaic systems. Use of thin film technology and thin foil substrate such as 5-mil thick stainless steel foil or 1-mil thick Ti would result in considerable costs savings. Another important aspect is manufacturing cost. Current single crystal technology for space power can cost more than $ 300 per watt at the array level and weigh more than 1 kg/sq m equivalent to specific power of approx. 65 W/kg. Thin film material such as CuIn1-xGaxS2 (CIGS2), CuIn(1-x)Ga(x)Se(2-y)S(y) (CIGSS) or amorphous hydrogenated silicon (a-Si:H) may be able to reduce both the cost and mass per unit area by an order of magnitude. Manufacturing costs for solar arrays are an important consideration for total spacecraft budget. For a medium sized 5kW satellite for example, the array manufacturing cost alone may exceed $ 2 million. Moving to thin film technology could reduce this expense to less than $ 500K. Earlier publications have demonstrated the potential of achieving higher efficiencies from CIGSS thin film solar cells on 5-mil thick stainless steel foil as well as initial stages of facility augmentation for depositing thin film solar cells on larger (6 in x 4 in) substrates. This paper presents the developmental study of achieving stress free Mo coating; uniform coatings of Mo back contact and metallic precursors. The paper also presents the development of sol gel process, refurbishment of selenization/sulfurization furnace, chemical bath deposition (CBD) for n-type CdS and scrubber for detoxification of H2S and H2Se gases.

Sputtered (barium(x), strontium(1-x))titanate, BST, thin films on flexible copper foils for use as a non-linear dielectric

NASA Astrophysics Data System (ADS)

Laughlin, Brian James

Ferroelectric thin film dielectrics have a non-linear DC bias dependent permittivity and can be used as the dielectric between metal electrodes to make tunable Metal-Insulator-Metal (MIM) capacitors. Varactors can be used to change the resonance frequency of a circuit allowing high speed frequency switching intra- and inter-band. 2-D geometric arrays of circuitry, where resonant frequency is independently controlled by tunable elements in each section of the array, allow electromagnetic radiation to be focused and the wave front spatial trajectory controlled. BST thin films varactors allow large DC fields to be applied with modest voltages providing large tunabilities. If ferroelectric thin film based devices are to complement or supplant semiconductor varactors as tunable elements then devices must be synthesized using a low cost processing techniques. The Film on Foil process methodology for depositing BST thin films on copper foil substrates was used to create BST/Cu specimens. Sputtering conditions were determined via BST deposition on platinized silicon. Sputtered BST thin films were synthesized on Cu foil substrates and densified using high T, controlled pO2 anneals. XRD showed the absence of Cu2O in as-deposited, post crystallization annealed, and post "re-ox" annealed state. Data showed a polycrystalline BST microstructure with a 55--80 nm grain size and no copper oxidation. HRTEM imaging qualitatively showed evidence of an abrupt BST/Cu interface free from oxide formation. Dielectric properties of Cu/BST/Pt MIM devices were measured as a function of DC bias, frequency, and temperature. A permittivity of 725 was observed with tunability >3:1 while zero bias tan delta of 0.02 saturating to tan delta < 0.003 at high DC bias. No significant frequency dispersion was observed over five decades of frequency. Temperature dependent measurements revealed a broad ferroelectric transition with a maximum at -32°C which sustains a large tunability over -150°C to 150°C. Sputtered BST thin films on copper foils show comparable dielectric properties to CVD deposited films on platinized silicon substrates proving sputtered BST/Cu specimens can reproduce excellent properties using a more cost-effective processing approach. A concept for reducing the temperature dependence was explored. Stacks of multiple compositions of BST thin films were considered as an extension of core-shell structures to a thin film format. Temperature profiles of BST/Cu films were modeled and mathematically combined in simulations of multi-composition film stacks. Simulations showed singular composition BST thin films could meet X7R specifications if a film has a 292 K < TC < 330 K. Simulations of series connected film stacks show only modest temperature profile broadening. Parallel connected dual composition film stacks showed a 75°C temperature range with essentially flat capacitance by simulating compositions that create a DeltaTC = 283°C. Maximum permittivity and temperature profile shape independent of film thickness or composition were assumed for simulations. BST/Cu thickness and compositions series were fabricated and dielectric properties characterized. These studies showed films could be grown from 300 nm and approaching 1 mum without changing the dielectric temperature response. In studying BST composition, an increasing TC shift was observed when increasing Ba mole fraction in BST thin films while tunability >3:1 was maintained. These results provide a route for creating temperature stable capacitors using a BST/Cu embodiment. An effort to reduce surface roughness of copper foil substrates adversely impacted BST film integrity by impairing adhesion. XPS analysis of high surface roughness commercially obtained Cu foils revealed a surface treatment of Zn-Cu-O that was not present on smooth Cu, thus an investigation of surface chemistry was conducted. Sessile drop experiments were performed to characterize Cu-BST adhesion and the effects of metallic Zn and ZnO in this system. The study revealed the work of adhesion of Cu-BST, WCu-BSTa ≈ 0.60 J m-2, an intermediate value relative to noble metals commonly used as electrodes and substrates for electroceramics. Examination of metallic Zn-BST adhesion revealed a dramatic decrease of WZn-BSTa ≈ 0.13 J m-2, while increasing the content of Zn in metallic (Cux,Zn1-x) alloys monotonically reduced WCux,Zn1-x -BSTa . Conversely, a Cu-ZnO interface showed a large work of adhesion, WCu-ZnOa = 2.0 J m-2. These results indicate that a ZnO interlayer between the substrate Cu and the BST thin film provides adequate adhesion for robust films on flexible copper foil substrates. Additionally, this study provided characterization of adhesion for Zn-Al2O3 and Zn-BST; data that does not exist in the open literature. A process has been developed for preparing ultra-smooth copper foils by evaporation and subsequent peel-off of copper metal layers from glass slides. These 15 mum thick substrates exhibited roughness values between 1 and 2 nm RMS and 9 nm RMS over 25 mum2 and 100 mum2 analysis areas, respectively. The deposition and crystallization of BST layers on these ultra-smooth foils is demonstrated. The fully processed dielectric layers exhibited field tunability >5:1, and could withstand fields >750 kV cm-1. High field loss tangents below 0.007 were observed, making these materials excellent candidates for microwave devices. Finally, a process of lamination and contact lithography was used to demonstrate patterning of micron-scale features suitable for microwave circuit element designs.

Calibration of thin-foil manganin gauge in ALOX material

NASA Astrophysics Data System (ADS)

Benham, R. A.; Weirick, L. J.; Lee, L. M.

1996-05-01

The purpose of this program was to develop a calibration curve (stress as a function of change in gauge resistance/gauge resistance) and to obtain gauge repeatability data for Micro-Measurements stripped manganin thin-foiled gauges up to 6.1 GPa in ALOX (42% by volume alumina in Epon 828 epoxy) material. A light-gas gun was used to drive an ALOX impactor into the ALOX target containing four gauges in a centered diamond arrangement. Tilt and velocity of the impactor were measured along with the gauge outputs. Impact stresses from 0.5 to 6.1 GPa were selected in increments of 0.7 GPa with duplicate tests done at 0.5, 3.3 and 6.1 GPa. A total of twelve tests was conducted using ALOX. Three initial tests were done using polymethyl methacrylate (PMMA) as the impactor and target at an impact pressure of 3.0 GPa for comparison of gauge output with analysis and literature values. The installed gauge, stripped of its backing, has a nominal thickness of 5 μm. The thin gauge and high speed instrumentation allowed higher time resolution measurements than can be obtained with manganin wire.

Time-resolved K α spectroscopy measurements of hot-electron equilibration dynamics in thin-foil solid targets: Collisional and collective effects

DOE PAGES

Nilson, P. M.; Solodov, A. A.; Davies, J. R.; ...

2015-09-25

Time-resolved K α spectroscopy measurements from high-intensity laser interactions with thin-foil solid targets are reviewed. Thin Cu foils were irradiated with 1- to 10-J, 1-ps pulses at focused intensities from 10 18 to 10 19 W/cm 2. The experimental data show K α-emission pulse widths from 3 to 6 ps, increasing with laser intensity. The time-resolved K α-emission data are compared to a hot-electron transport and K α-production model that includes collisional electron-energy coupling, resistive heating, and electromagnetic field effects. The experimental data show good agreement with the model when a reduced ponderomotive scaling is used to describe the initialmore » mean hot-electron energy over the relevant intensity range.« less

Multi-dimensional effects in radiation pressure acceleration of ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, V. K., E-mail: tripathivipin@yahoo.co.in

A laser carries momentum. On reflection from an ultra-thin overdense plasma foil, it deposits recoil momentum on the foil, i.e. exerts radiation pressure on the foil electrons and pushes them to the rear. The space charge field thus created takes the ions along, accelerating the electron-ion double layer as a single unit. When the foil has surface ripple, of wavelength comparable to laser wavelength, the radiation pressure acts non-uniformly on the foil and the perturbation grows as Reyleigh-Taylor (RT) instability as the foil moves. The finite spot size of the laser causes foil to bend. These effects limit the quasi-monomore » energy acceleration of ions. Multi-ion foils, e.g., diamond like carbon foil embedded with protons offer the possibility of suppressing RT instability.« less

Birefringence and dichroism of poly(vinyl-alcohol) foils containing phthalazinium ylids

NASA Astrophysics Data System (ADS)

Rogojanu, Alina; Dascalu, Carmen Felicia; Zelinschi, Beatrice Carmen; Caprosu, Maria; Dorohoi, Dana Ortansa

2011-10-01

Pure and colored with phthalazinium ylids poly(vinyl-alcohol) (PVA) foils were stretched under gentile heating. The birefringence of the thin foils was determined with a Babinet compensator standardized for yellow radiation of a Sodium lamp. The determined birefringence of the colored PVA foils is higher than that of the pure PVA foils. This fact indicates that the phthalazinium ylids facilitate the increase in the anisotropy of the stretched foils. The visible absorption electronic band of phthalazinium ylids was used to estimate the dichroic ratio and the degree of order of the ylid molecules in the stretched PVA foils. An increase in dichroism and birefringence with the degree of stretching has been evidenced for uncolored and colored PVA foils.

Investigation of ablation of thin foil aluminum ribbon array at 1.5 MA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Fan, E-mail: yefan1931@126.com; Li, Zhenghong; Chen, Faxin

We present experimental studies of initiation and ablation of a thin foil aluminum ribbon array at the 1.5 MA current level. In contrast to the previous work, we employ ribbon arrays with different ribbon gap parameters to investigate how this affects plasma initiation and foil ablation. Gated narrowband ultraviolet imaging indicated that the current was disorderly distributed at early period of discharge. But later on, it became axially stable and azimuthally symmetrical even for load with a gap as small as 0.1 mm. Using magnetic field probes installed inside and outside the array, we also observed that precursor current at positionsmore » with a distance of less than 2.7 mm to the central axis for 4-mm-radius arrays decreased when ribbon gap became small. Results of 0.2 mm gap ribbon array showed an evidence that ribbons can be merged. These observations imply that thin foil ribbon arrays may have potential applications in z-pinch experiments on large scale pulsed power facilities.« less

Solid Lubricants for Oil-Free Turbomachinery

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher

2005-01-01

Recent breakthroughs in gas foil bearing solid lubricants and computer based modeling has enabled the development of revolulionary Oil-Free turbomachinery systems. These innovative new and solid lubricants at low speeds (start-up and shut down). Foil bearings are hydrodynamic, self acting fluid film bearings made from thin, flexible sheet metal foils. These thin foils trap a hydrodynamic lubricating air film between their surfaces and moving shaft surface. For low temperature applications, like ainrafl air cycle machines (ACM's), polymer coatings provide important solid lubrication during start-up and shut down prior to the development of the lubricating fluid film. The successful development of Oil-Free gas turbine engines requires bearings which can operate at much higher temperatures (greater than 300 C). To address this extreme solid lubrication need, NASA has invented a new family of compostie solid lubricant coatings, NASA PS300.

Perforating Thin Metal Sheets

NASA Technical Reports Server (NTRS)

Davidson, M. E.

1985-01-01

Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

Anomalous transmission of an ultrashort ionizing laser pulse through a thin foil.

PubMed

Ferrante, G; Zarcone, M; Uryupin, S A

2003-08-22

The formation of a highly anisotropic photoelectron velocity distribution as a result of the interaction of a powerful ultrashort laser pulse with a thin foil is found to yield a large skin-layer depth and an anomalous increase of the transmission coefficient. The physical reason for the effect is the influence of the incident wave magnetic field, through the Lorenz force, on the electron kinetics in the skin layer.

Status of flexible CIS research at ISET

NASA Technical Reports Server (NTRS)

Basol, B. M.; Kapur, V. K.; Minnick, A.; Halani, A.; Leidholm, C. R.

1994-01-01

Polycrystalline thin film solar cells fabricated on light-weight, flexible substrates are very attractive for space applications. In this work CulnSe2 (CIS) based thin film devices were processed on metallic foil substrates using the selenization technique. CIS deposition method involved reaction of electron-bean evaporated Cu-In precursor layers with a selenizing atmosphere at around 400 C. Several metallic foils such as Mo, Ti, Al, Ni, and Cu were evaluated as possible substrates for these devices. Solar cells with AM1.5 efficiencies of 9.0-9.34 percent and good mechanical integrity were demonstrated on Mo and Ti foils. Monolithic integration of these devices was also demonstrated up to 4 in x 4 in size.

Bi-Directional Ion Emission from Massive Gold Cluster Impacts on Nanometric Carbon Foils.

PubMed

Debord, J Daniel; Della-Negra, Serge; Fernandez-Lima, Francisco A; Verkhoturov, Stanislav V; Schweikert, Emile A

2012-04-12

Carbon cluster emission from thin carbon foils (5-40 nm) impacted by individual Au(n) (+q) cluster projectiles (95-125 qkeV, n/q = 3-200) reveals features regarding the energy deposition, projectile range, and projectile fate in matter as a function of the projectile characteristics. For the first time, the secondary ion emission from thin foils has been monitored simultaneously in both forward and backward emission directions. The projectile range and depth of emission were examined as a function of projectile size, energy, and target thickness. A key finding is that the massive cluster impact develops very differently from that of a small polyatomic projectile. The range of the 125 qkeV Au(100q) (+q) (q ≈ 4) projectile is estimated to be 20 nm (well beyond the range of an equal velocity Au(+)) and projectile disintegration occurs at the exit of even a 5 nm thick foil.

Bi-Directional Ion Emission from Massive Gold Cluster Impacts on Nanometric Carbon Foils

PubMed Central

DeBord, J. Daniel; Della-Negra, Serge; Fernandez-Lima, Francisco A.; Verkhoturov, Stanislav V.; Schweikert, Emile A.

2012-01-01

Carbon cluster emission from thin carbon foils (5–40 nm) impacted by individual Aun+q cluster projectiles (95–125 qkeV, n/q = 3–200) reveals features regarding the energy deposition, projectile range, and projectile fate in matter as a function of the projectile characteristics. For the first time, the secondary ion emission from thin foils has been monitored simultaneously in both forward and backward emission directions. The projectile range and depth of emission were examined as a function of projectile size, energy, and target thickness. A key finding is that the massive cluster impact develops very differently from that of a small polyatomic projectile. The range of the 125 qkeV Au100q+q (q ≈ 4) projectile is estimated to be 20 nm (well beyond the range of an equal velocity Au+) and projectile disintegration occurs at the exit of even a 5 nm thick foil. PMID:22888385

Method for fabricating uranium foils and uranium alloy foils

DOEpatents

Hofman, Gerard L [Downers Grove, IL; Meyer, Mitchell K [Idaho Falls, ID; Knighton, Gaven C [Moore, ID; Clark, Curtis R [Idaho Falls, ID

2006-09-05

A method of producing thin foils of uranium or an alloy. The uranium or alloy is cast as a plate or sheet having a thickness less than about 5 mm and thereafter cold rolled in one or more passes at substantially ambient temperatures until the uranium or alloy thereof is in the shape of a foil having a thickness less than about 1.0 mm. The uranium alloy includes one or more of Zr, Nb, Mo, Cr, Fe, Si, Ni, Cu or Al.

NMR of samples containing metal foils.

PubMed

Xiong, J; Lock, H; Tao, T; Keeler, C; Maciel, G E

1999-07-01

By using spool configurations of a sample containing aluminum foil, in which the axis of the spool is collinear with the RF coil axis, one can obtain high-quality 13C NMR spectra of static samples of organic material attached to the aluminum foil. By combining such a spool configuration (or, alternatively, analogous samples containing equivalent amounts of fine aluminum powder) with the magic-angle hopping (MAH) technique, one can achieve a high degree of isotropic averaging of the 13C spectrum. This opens to NMR techniques the study of a variety of samples containing macroscopic pieces of metal foils, e.g., thin films deposited on metal foils and electrochemical systems with species adsorbed on metal-foil electrodes.

X-ray optics made from thin plastic foils

NASA Astrophysics Data System (ADS)

Schnopper, H. W.; Barbera, M.; Ingram, R.; Silver, E.; Romaine, S.; Bandler, S.; Murray, S.; Christensen, F. E.; Hussain, A.; Collura, A.

2000-10-01

New design concepts and materials can be used to produce lightweight, thin foil approximations, to Wolter I and other X-ray optics. Structures are designed around a central hub and spacers that connect two (or three) spoked wheels. Figure defining, thin pins span the distance between the wheels. Thin, metal coated or multilayered, plastic foils can be formed into full cones, cylinders or spirals for X-ray telescopes or lenses. High resolution X-ray scattering data were obtained for single foils at Cu K (8 KeV). Multi-energy (0.28 - 8 KeV) data were obtained with a multichannel plate imager in a 17 m beam line with a point-to-point focusing, cylindrical X-ray lens with 14 shells. The largest shell has a diameter of 175 mm and a length of 100 mm. Typical images have a FWHM of 20 arcsec. The results indicate that a 60 cm diameter, 4.65 m focal length X-ray telescope can have an HPD of considerably less than 2 arcmin. This research is supported, in part by NASA Grant NAG5-5268, ONR Grant N00014-95-1-1248, and by institutional funding from the Smithsonian Astrophysical Observatory. The SAO multilayer facility receives support from NASA Grant NAG5-5095. This work made use of the MRSEC Shared Experimental Facilities at MIT supported by NSF Grant DMR94-00334.

Microstructure Evolution and Composition Control During the Processing of Thin-Gage Metallic Foil

NASA Astrophysics Data System (ADS)

Semiatin, S. L.; Gross, M. E.; Matson, D. W.; Bennett, W. D.; Bonham, C. C.; Ustinov, A. I.; Ballard, D. L.

2012-12-01

The manufacture of thin-gage superalloy and gamma-titanium-aluminide foil products via near-conventional thermomechanical processing and two different vapor-deposition methods was investigated. Thermomechanical processing was based on hot-pack rolling of plate and sheet. Foils of the superalloy LSHR and the near-gamma titanium aluminide Ti-45.5Al-2Cr-2Nb made by this approach exhibited excellent gage control and fine two-phase microstructures. The vapor-phase techniques used magnetron sputtering (MS) of a target of the desired product composition or electron-beam physical vapor deposition (EBPVD) of separate targets of the specific alloying elements. Thin deposits of LSHR and Ti-48Al-2Cr-2Nb made by MS showed uniform thickness/composition and an ultrafine microstructure. However, systematic deviations from the specific target composition were found. During subsequent heat treatment, the microstructure of the MS samples showed various degrees of grain growth and coarsening. Foils of Ti-43Al and Ti-51Al-1V fabricated by EBPVD were fully dense. The microstructures developed during EBPVD were interpreted in terms of measured phase equilibria and the dependence of evaporant flux on temperature.

Thin-Film Solar Cells on Metal Foil Substrates for Space Power

NASA Technical Reports Server (NTRS)

Raffaelle, Ryne P.; Hepp, Aloysius F.; Hoffman, David J.; Dhere, N.; Tuttle, J. R.; Jin, Michael H.

2004-01-01

Photovoltaic arrays have played a key role in power generation in space. The current technology will continue to evolve but is limited in the important mass specific power metric (MSP or power/weight ratio) because it is based on bulk crystal technology. The objective of this research is to continue development of an innovative photovoltaic technology for satellite power sources that could provide up to an order of magnitude saving in both weight and cost, and is inherently radiation-tolerant through use of thin film technology and thin foil substrates such as 5-mil thick stainless steel foil or 1-mil thick Ti. Current single crystal technology for space power can cost more than $300 per watt at the array level and weigh more than 1 kg/sq m equivalent to specific power of approx. 65 W/kg. Thin film material such as CuIn(1-x),Ga(x)S2, (CIGS2), CuIn(1-x), G(x)Se(2-y),S(y), (CIGSS) or amorphous hydrogenated silicon (a-Si:H) may be able to reduce both the cost and mass per unit area by an order of magnitude. Manufacturing costs for solar arrays are an important consideration for total spacecraft budget. For a medium sized 5kW satellite, for example, the array manufacturing cost alone may exceed $2 million. Moving to thin film technology could reduce this expense to less than $500 K. Previous work at FSEC demonstrated the potential of achieving higher efficiencies from CIGSS thin film solar cells on 5-mil thick stainless steel foil as well as initial stages of facility augmentation for depositing thin film solar cells on larger (6"x 4") substrates. This paper presents further progress in processing on metal foil substrates. Also, previous work at DayStar demonstrated the feasibility of flexible-thin-film copper-indium-gallium-diselenide (CIGS) solar cells with a power-to-weight ratio in excess of 1000 W/kg. We will comment on progress on the critical issue of scale-up of the solar cell absorber deposition process. Several important technical issues need to be resolved to realize the benefits of lightweight technologies for solar arrays, such as: monolithic interconnects, lightweight array structures, and new ultra-light support and deployment mechanisms. Once the technology has gained spaceflight certification it should find rapid acceptance in specific satellite markets.

A concept for Z-dependent microbunching measurements with coherent X-ray transition radiation in a sase FEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumpkin, A.H.; Fawley, W.M.; Rule, D.W.

We present an adaptation of the measurements performed in the visible-to-VUV regime of the z-dependent microbunching in a self-amplified spontaneous emission (SASE) free-electron laser (FEL). In these experiments a thin metal foil was used to block the more intense SASE radiation and to generate coherent optical transition radiation (COTR) as one source in a two-foil interferometer. However, for the proposed x-ray SASE FELs, the intense SASE emission is either too strongly transmitted at 1.5 Angstrom or the needed foil thickness for blocking scatters the electron beam too much. Since x-ray transition radiation (XTR) is emitted in an annulus with openingmore » angle 1/g = 36 mrad for 14.09-GeV electrons, we propose using a thin foil or foil stack to generate the XTR and coherent XTR (CXTR) and an annular crystal to wavelength sort the radiation. The combined selectivity in angle and wavelength will favor the CXTR over SASE by about eight orders of magnitude. Time-dependent GINGER simulations support the z-dependent gain evaluation plan.« less

Thin film filter lifetesting results in the extreme ultraviolet

NASA Technical Reports Server (NTRS)

Vedder, P. W.; Vallerga, J. V.; Gibson, J. L.; Stock, J.; Siegmund, O. H. W.

1993-01-01

We present the results of the thin film filter lifetesting program conducted as part of the NASA Extreme Ultraviolet Explorer (EUVE) satellite mission. This lifetesting program is designed to monitor changes in the transmission and mechanical properties of the EUVE filters over the lifetime of the mission (fabrication, assembly, launch and operation). Witness test filters were fabricated from thin film foils identical to those used in the flight filters. The witness filters have been examined and calibrated periodically over the past seven years. The filters have been examined for evidence of pinholing, mechanical degradation, and oxidation. Absolute transmissions of the flight and witness filters have been measured in the extreme ultraviolet (EUV) over six orders of magnitude at numerous wavelengths using the Berkeley EUV Calibration Facility.

Foil focusing of relativistic electron beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekdahl, Jr., Carl August

2017-10-26

When an intense relativistic electron beams (IREB) passes through a grounded metal foil, the transverse electric field due to the beam space charge is locally shorted out, and the beam is focused by the magnetic field of its current. The effect can be treated as focusing by a thin lens with first order aberration. Expressions for the focal length and aberration coefficient of the equivalent thin lens are developed in this note. These are then applied to practical examples representative of IREB research at Los Alamos National Laboratory.

Effect of mechanical strain on mobility of polycrystalline silicon thin-film transistors fabricated on stainless steel foil

NASA Astrophysics Data System (ADS)

Kuo, Po-Chin; Jamshidi-Roudbari, Abbas; Hatalis, Miltiadis

2007-12-01

The effect of uniaxial tensile strain parallel to the channel on mobility of polycrystalline silicon thin-film transistors (TFTs) on stainless steel foil has been investigated. The electron mobility increases by 20% while the hole mobility decreases by 6% as the strain increases to 0.5%, and both followed by saturation as the strain increases further. The off current decreases for both types of TFTs under strain. All TFTs remained functional at the applied strain of 1.13%.

Lead zirconate titanate (PZT)-based thin film capacitors for embedded passive applications

NASA Astrophysics Data System (ADS)

Kim, Taeyun

Investigations on the key processing parameters and properties relationship for lead zirconate titanate (PZT, 52/48) based thin film capacitors for embedded passive capacitor application were performed using electroless Ni coated Cu foils as substrates. Undoped and Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil by chemical solution deposition. For PZT (52/48) thin film capacitors on electroless Ni coated Cu foil, voltage independent (zero tunability) capacitance behavior was observed. Dielectric constant reduced to more than half of the identical capacitor processed on Pt/SiO2/Si. Dielectric properties of the capacitors were mostly dependent on the crystallization temperature. Capacitance densities of almost 350 nF/cm2 and 0.02˜0.03 of loss tangent were routinely measured for capacitors crystallized at 575˜600°C. Leakage current showed dependence on film thickness and crystallization temperature. From a two-capacitor model, the existence of a low permittivity interface layer (permittivity ˜30) was suggested. For Ca-doped PZT (52/48) thin film capacitors prepared on Pt, typical ferroelectric and dielectric properties were measured up to 5 mol% Ca doping. When Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil, phase stability was influenced by Ca doping and phosphorous content. Dielectric properties showed dependence on the crystallization temperature and phosphorous content. Capacitance density of ˜400 nF/cm2 was achieved, which is an improvement by more than 30% compared to undoped composition. Ca doping also reduced the temperature coefficient of capacitance (TCC) less than 10%, all of them were consistent in satisfying the requirements of embedded passive capacitor. Leakage current density was not affected significantly by doping. To tailor the dielectric and reliability properties, ZrO2 was selected as buffer layer between PZT and electroless Ni. Only RF magnetron sputtering process could yield stable ZrO2 layers on electroless Ni coated Cu foil. Other processes resulted in secondary phase formation, which supports the reaction between PZT capacitor and electroless Ni might be dominated by phosphorous component. (Abstract shortened by UMI.)

Tungsten bridge for the low energy ignition of explosive and energetic materials

DOEpatents

Benson, David A.; Bickes, Jr., Robert W.; Blewer, Robert S.

1990-01-01

A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose.

Simulation of the energy spectra of original versus recombined H{sub 2}{sup +} molecular ions transmitted through thin foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barriga-Carrasco, Manuel D.; Garcia-Molina, Rafael

2004-09-01

This work presents the results of computer simulations for the energy spectra of original versus recombined H{sub 2}{sup +} molecular ions transmitted through thin amorphous carbon foils, for a broad range of incident energies. A detailed description of the projectile motion through the target has been done, including nuclear scattering and Coulomb repulsion as well as electronic self-retarding and wake forces; the two latter are calculated in the dielectric formalism framework. Differences in the energy spectra of recombined and original transmitted H{sub 2}{sup +} molecular ions clearly appear in the simulations, in agreement with the available experimental data. Our simulationmore » code also differentiates the contributions due to original and to recombined H{sub 2}{sup +} molecular ions when the energy spectra contain both contributions, a feature that could be used for experimental purposes in estimating the ratio between the number of original and recombined H{sub 2}{sup +} molecular ions transmitted through thin foils.« less

Direct hot slumping and accurate integration process to manufacture prototypal x-ray optical units made of glass

NASA Astrophysics Data System (ADS)

Civitani, M.; Ghigo, M.; Basso, S.; Proserpio, L.; Spiga, D.; Salmaso, B.; Pareschi, G.; Tagliaferri, G.; Burwitz, V.; Hartner, G.; Menz, B.; Bavdaz, M.; Wille, E.

2013-09-01

X-ray telescopes with very large collecting area, like the proposed International X-ray Observatory (IXO, with around 3 m2 at 1 keV), need to be composed of a large number high quality mirror segments, aiming at achieving an angular resolution better than 5 arcsec HEW (Half-Energy-Width). A possible technology to manufacture the modular elements that will compose the entire optical module, named X-ray Optical Units (XOUs), consists of stacking in Wolter-I configuration several layers of thin foils of borosilicate glass, previously formed by hot slumping. The XOUs are subsequently assembled to form complete multi-shell optics with Wolter-I geometry. The achievable global angular resolution of the optic relies on the required surface shape accuracy of slumped foils, on the smoothness of the mirror surfaces and on the correct integration and co-alignment of the mirror segments. The Brera Astronomical Observatory (INAF-OAB) is leading a study, supported by ESA, concerning the implementation of the IXO telescopes based on thin slumped glass foils. In addition to the opto-mechanical design, the study foresees the development of a direct hot slumping thin glass foils production technology. Moreover, an innovative assembly concept making use of Wolter-I counter-form moulds and glass reinforcing ribs is under development. The ribs connect pairs of consecutive foils in an XOU stack, playing a structural and a functional role. In fact, as the ribs constrain the foil profile to the correct shape during the bonding, they damp the low-frequency profile errors still present on the foil after slumping. A dedicated semirobotic Integration MAchine (IMA) has been realized to this scope and used to build a few integrated prototypes made of several layers of slumped plates. In this paper we provide an overview of the project, we report the results achieved so far, including full illumination intra-focus X-ray tests of the last integrated prototype that are compliant with a HEW of around 17''.

Simulation of thin aluminium-foil in the packaging industry

NASA Astrophysics Data System (ADS)

Eskil, Andreasson; Lindström, Tommy; Käck, Britta; Malmberg, Christoffer; Asp, Ann-Magret

2017-10-01

This work present an approach of how to account for the anisotropic mechanical material behaviour in the simulation models of the thin aluminium foil layer (≈10 µm) used in the Packaging Industry. Furthermore, the experimental results from uniaxial tensile tests are parameterised into an analytical expression and the slope of the hardening subsequently extended way beyond the experimental data points. This in order to accommodate the locally high stresses present in the experiments at the neck formation. An analytical expression, denominated Ramberg-Osgood, is used to describe the non-linear mechanical behaviour. Moreover it is possible with a direct method to translate the experimental uniaxial tensile test results into useful numerical material model parameters in Abaqus™. In addition to this the extended material behaviour including the plastic flow i.e. hardening, valid after onset of localisation, the described procedure can also capture the microscopic events, i.e. geometrical thinning, ongoing in the deformation of the aluminium foil. This method has earlier successfully been applied by Petri Mäkelä for paperboard material [1]. The engineering sound and parameterised description of the mechanical material behaviour facilitates an efficient categorisation of different aluminium foil alloys and aid the identification of the correct anisotropic (RD/TD/45°) mechanical material behaviour derived from the physical testing.

Short protection device for stack of electrolytic cells

DOEpatents

Katz, Murray; Schroll, Craig R.

1985-10-22

Electrical short protection is provided in an electrolytic cell stack by the combination of a thin, nonporous ceramic shield and a noble metal foil disposed on opposite sides of the sealing medium in a gas manifold gasket. The thin ceramic shield, such as alumina, is placed between the porous gasket and the cell stack face at the margins of the negative end plate to the most negative cells to impede ion current flow. The noble metal foil, for instance gold, is electrically coupled to the negative potential of the stack to collect positive ions at a harmless location away from the stack face. Consequently, corrosion products from the stack structure deposit on the foil rather than on the stack face to eliminate electrical shorting of cells at the negative end of the stack.

Observation of alpha particle loss from JET plasmas during ion cyclotron resonance frequency heating using a thin foil Faraday cup detector array.

PubMed

Darrow, D S; Cecil, F E; Kiptily, V; Fullard, K; Horton, A; Murari, A

2010-10-01

The loss of MeV alpha particles from JET plasmas has been measured with a set of thin foil Faraday cup detectors during third harmonic heating of helium neutral beam ions. Tail temperatures of ∼ 2 MeV have been observed, with radial scrape off lengths of a few centimeters. Operational experience from this system indicates that such detectors are potentially feasible for future large tokamaks, but careful attention to screening rf and MHD induced noise is essential.

CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power

NASA Technical Reports Server (NTRS)

Dhere, Neelkanth G.; Ghongadi, Shantinath R.; Pandit, Mandar B.; Jahagirdar, Anant H.; Scheiman, David

2002-01-01

CuIn(1-x)Ga(x)S2 (CIGS2) thin-film solar cells are of interest for space power applications because of the near optimum bandgap for AM0 solar radiation in space. CIGS2 thin film solar cells on flexible stainless steel (SS) may be able to increase the specific power by an order of magnitude from the current level of 65 Wkg(sup -1). CIGS solar cells are superior to the conventional silicon and gallium arsenide solar cells in the space radiation environment. This paper presents research efforts for the development of CIGS2 thin-film solar cells on 127 micrometers and 20 micrometers thick, bright-annealed flexible SS foil for space power. A large-area, dual-chamber, inline thin film deposition system has been fabricated. The system is expected to provide thickness uniformity of plus or minus 2% over the central 5" width and plus or minus 3% over the central 6" width. During the next phase, facilities for processing larger cells will be acquired for selenization and sulfurization of metallic precursors and for heterojunction CdS layer deposition both on large area. Small area CIGS2 thin film solar cells are being prepared routinely. Cu-rich Cu-Ga/In layers were sputter-deposited on unheated Mo-coated SS foils from CuGa (22%) and In targets. Well-adherent, large-grain Cu-rich CIGS2 films were obtained by sulfurization in a Ar: H2S 1:0.04 mixture and argon flow rate of 650 sccm, at the maximum temperature of 475 C for 60 minutes with intermediate 30 minutes annealing step at 120 C. Samples were annealed at 500 C for 10 minutes without H2S gas flow. The intermediate 30 minutes annealing step at 120 C was changed to 135 C. p-type CIGS2 thin films were obtained by etching the Cu-rich layer segregated at the surface using dilute KCN solution. Solar cells were completed by deposition of CdS heterojunction partner layer by chemical bath deposition, transparent-conducting ZnO/ZnO: Al window bilayer by RF sputtering, and vacuum deposition of Ni/Al contact fingers through metal mask. PV parameters of a CIGS2 solar cell on 127 micrometers thick SS flexible foil measured under AM 0 conditions at NASA GRC were: V(sub oc) = 802.9 mV, J(sub sc) = 25.07 mA per square centimeters, FF = 60.06%, and efficiency 0 = 8.84%. For this cell, AM 1.5 PV parameters measured at NREL were: V(sub oc) = 788 mV, J(sub sc) = 19.78 mA per square centimeter, FF = 59.44%, efficiency 0 = 9.26%. Quantum efficiency curve showed a sharp QE cutoff equivalent to CIGS2 bandgap of approximately 1.50 eV, fairly close to the optimum value for efficient AM0 PV conversion in the space.

Large-area thin self-supporting carbon foils with MgO coatings

NASA Astrophysics Data System (ADS)

Stolarz, Anna; Maier-Komor, Peter

2002-03-01

Large area self-supporting carbon foils in the thickness of range of 8-22 μg/cm 2, coated with approximately 4 μg/cm 2 MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm 2. Problems related to the parting agent preparation, floating procedure, and mounting onto frames are discussed. Special precautions necessary to avoid damage during foil drying, storage and transportation are suggested.

Joining of materials using laser heating

DOEpatents

Cockeram, Brian V.; Hicks, Trevor G.; Schmid, Glenn C.

2003-07-01

A method for diffusion bonding ceramic layers such as boron carbide, zirconium carbide, or silicon carbide uses a defocused laser beam to heat and to join ceramics with the use of a thin metal foil insert. The metal foil preferably is rhenium, molybdenum or titanium. The rapid, intense heating of the ceramic/metal/ceramic sandwiches using the defocused laser beam results in diffusive conversion of the refractory metal foil into the ceramic and in turn creates a strong bond therein.

Tungsten bridge for the low energy ignition of explosive and energetic materials

DOEpatents

Benson, D.A.; Bickes, R.W. Jr.; Blewer, R.S.

1990-12-11

A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose. 2 figs.

Influence of UV and Gamma radiations on the induced birefringence of stretched poly(vinyl) alcohol foils

NASA Astrophysics Data System (ADS)

Nechifor, Cristina-Delia; Zelinschi, Carmen Beatrice; Dorohoi, Dana-Ortansa

2014-03-01

The aim of our paper is to evidence the influence of Gamma and UV radiations on the induced birefringence of poly(vinyl alcohol) stretched foils. Thin foils of PVA were prepared and dried without modifying their surfaces. The polymeric foils were irradiated from 15 min to 6 h using UV and Gamma radiations. The induced by stretching under heating birefringence of PVA films was measured at λ = 589.3 nm with a Babinet Compensator. Physico-chemical processes (photo stabilization, photo degradation, oxidation) induced by irradiation of polymer matrix influence both the stretching degree and the anisotropy of etired foils. An increase of birefringence versus the stretching ratio of the PVA foils was evidenced for all studied samples. The dependence of the birefringence on the exposure time, stretching ratio and nature of radiation was also confirmed.

Thin film fabrication and system integration test run for a microactuator for a tuneable lens

NASA Astrophysics Data System (ADS)

Hoheisel, Dominik; Rissing, Lutz

2014-03-01

An electromagnetic microactuator, for controlling of a tuneable lens, with an integrated electrostatic element is fabricated by thin film technology. The actuator consists of two parts: the first part with microcoil and flux guide and the second part with a ring shaped back iron on a polyimide membrane. The back iron is additionally useable as electrode for electrostatic measurement of the air gap and for electrostatic actuation. By attracting the back iron an optical liquid is displaced and forms a liquid lens inside the back iron ring covered by the membrane. For testing the thin film fabrication sequence, up-scaled systems are generated in a test run. To fabricate the flux guide in an easy and quick way, a Ni-Fe foil with a thickness of 50 μm is laminated on the Si-wafer. This foil is also utilized in the following fabrication sequence as seed layer for electroplating. Compared to Ni-Fe structures deposited by electroplating, the foil is featuring better soft magnetic properties. The foil is structured by wet chemical etching and the backside of the wafer is structured by deep reactive ion etching (DRIE). For post fabrication thinning, the polyimide membrane is treated by oxygen plasma etching. To align the back iron to the microcoil and the flux guide, a flip-chip-bonder is used during test run of system integration. To adjust a constant air gap, a water solvable polymer is tested. A two component epoxy and a polyimide based glue are compared for their bonding properties of the actuator parts.

P-doped strontium titanate grown using two target pulsed laser deposition for thin film solar cells

NASA Astrophysics Data System (ADS)

Man, Hamdi

Thin-film solar cells made of Mg-doped SrTiO3 p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg-doped SrTiO3 (STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg-doped STO thin-films were grown by using pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were doped successfully in the stoichiometry. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. UV/Vis Reflection spectroscopy showed that Mg-doped STO thin-films do not reflect significantly except in the ultraviolet region of the spectrum where the reflection percentage increased up to 80%. Self-doped STO thin-films, Indium Tin Oxide (ITO) thin films and stainless steel foil (SSF) were studied in order to observe their characteristics before employing them in Mg-doped STO based solar cells. Self-doped STO thin films were grown using PLD and the results showed that they are capable of serving as the n-type semiconductor in solar cell applications with oxygen vacancies in their structure and low reflectivity. Indium Tin Oxide thin-films grown by PLD system showed low 25-50 ?/square sheet resistance and very low reflection features. Finally, commercially available stainless steel foil substrates were excellent substrates for the inexpensive growth of these novel solar cells.

Extended foil capacitor with radially spoked electrodes

DOEpatents

Foster, James C.

1990-01-01

An extended foil capacitor has a conductive disk electrically connected in oncrushing contact to the extended foil. A conductive paste is placed through spaces between radial spokes on the disk to electrically and mechanically connect the extended foil to the disk.

METHOD OF MEASURING THE INTEGRATED ENERGY OUTPUT OF A NEUTRONIC CHAIN REACTOR

DOEpatents

Sturm, W.J.

1958-12-01

A method is presented for measuring the integrated energy output of a reactor conslsting of the steps of successively irradiating calibrated thin foils of an element, such as gold, which is rendered radioactive by exposure to neutron flux for periods of time not greater than one-fifth the mean life of the induced radioactlvity and producing an indication of the radioactivity induced in each foil, each foil belng introduced into the reactor immediately upon removal of its predecessor.

Flexible patch composed of PZT thin-film on stainless steel foil for energy harvesting from low-frequency human motions

NASA Astrophysics Data System (ADS)

Wang, Yin Jie; Chen, Chao Ting; Chen, Jiun Jung; Yeh, Sou Peng; Wu, Wen Jong

2015-03-01

To harvest energy from human motion and generate power for the emerging wearable devices, energy harvesters are required to work at very low frequency. There are several studies based on energy harvesting through human gait, which can generate significant power. However, when wearing these kind of devices, additional effort may be required and the user may feel uncomfortable when moving. The energy harvester developed here is composed of a 10 μm PZT thin-film deposited on 50 μm thick stainless steel foil by the aerosol deposition method. The PZT layer and the stainless steel foil are both very thin, thus the patch is highly flexible. The patch can be attached on the skin to harvester power through human motions such as the expansion of the chest region while breathing. The energy harvester will first be tested with a moving stage for power output measurements. The energy density can be determined for different deformation ranges and frequencies. The fabrication processes and testing results will all be detailed in this paper.

Micrometeoroids and debris on LDEF

NASA Technical Reports Server (NTRS)

Mandeville, Jean-Claude

1992-01-01

Part of the LDEF tray allocated to French Experiments (FRECOPA) was devoted to the study of dust particles. The tray was located on the face of LDEF directly opposed to the velocity vector. Two passive experiments were flown: a set of glass and metallic samples; and multilayer thin foil detectors. Crater size distribution made possible the evaluation of the incident microparticle flux in the near environment. Comparisons are made with measurements obtained on the other faces of LDEF and with results from similar experiments on the MIR. Of interest was the study of impact features on stacked thin foil detectors. The top foil acted as a shield, fragmenting the projectiles and spreading the fragments over the surface of the thick plate located underneath. EDS analysis has provided evidence of impactor fragments. Detectors consisting of a thin shield and thick bottom plate appear to offer a significantly higher return of data concerning chemical analysis of impactor residues than single plate detectors. The samples of various materials offer a unique opportunity for the study of the many processes involved upon hypervelocity impact phenomena.

Laser Radiation Pressure Acceleration of Monoenergetic Protons in an Ultra-Thin Foil

NASA Astrophysics Data System (ADS)

Eliasson, Bengt; Liu, Chuan S.; Shao, Xi; Sagdeev, Roald Z.; Shukla, Padma K.

2009-11-01

We present theoretical and numerical studies of the acceleration of monoenergetic protons in a double layer formed by the laser irradiation of an ultra-thin film. The stability of the foil is investigated by direct Vlasov-Maxwell simulations for different sets of laser-plasma parameters. It is found that the foil is stable, due to the trapping of both electrons and ions in the thin laser-plasma interaction region, where the electrons are trapped in a potential well composed of the ponderomo-tive potential of the laser light and the electrostatic potential due to the ions, and the ions are trapped in a potential well composed of the inertial potential in an accelerated frame and the electrostatic potential due to the electrons. The result is a stable double layer, where the trapped ions are accelerated to monoenergetic energies up to 100 MeV and beyond, which makes them suitable for medical applications cancer treatment. The underlying physics of trapped and untapped ions in a double layer is also investigated theoretically and numerically.

Exploring aligned-carbon-nanotubes@polyaniline arrays on household Al as supercapacitors.

PubMed

Huang, Fan; Lou, Fengliu; Chen, De

2012-05-01

Herein, we demonstrate a new approach towards the construction of supercapacitors consisting of carbon nanotubes (CNTs) and conducting polymers (ECPs) with high specific power, high specific energy, and stable cycling performance through a 3D design of a thin film of polyaniline (PANI) on an aligned small carbon nanotube (ACNT) array on household Al foils. The thin-film strategy is used to fully exploit the specific capacitance of PANI, and obtain regular pores, strong interaction between PANI and CNTs, and reduced electrical resistance for the electrodes. A facile process is developed to fabricate a highly flexible supercapacitor using this binder-free composite on household Al foil as the current collector. It exhibits high specific energy of 18.9 Wh kg(-1) , high maximum specific power of 11.3 kW kg(-1) of the active material in an aqueous electrolyte at 1.0 A g(-1) , and excellent rate performance and cycling stability. A high specific energy of 72.4 Wh kg(-1) , a high maximum specific power of 24.9 kW kg(-1) , and a good cycling performance of the active material are obtained in an organic electrolyte. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method of fabricating a uranium-bearing foil

DOEpatents

Gooch, Jackie G [Seymour, TN; DeMint, Amy L [Kingston, TN

2012-04-24

Methods of fabricating a uranium-bearing foil are described. The foil may be substantially pure uranium, or may be a uranium alloy such as a uranium-molybdenum alloy. The method typically includes a series of hot rolling operations on a cast plate material to form a thin sheet. These hot rolling operations are typically performed using a process where each pass reduces the thickness of the plate by a substantially constant percentage. The sheet is typically then annealed and then cooled. The process typically concludes with a series of cold rolling passes where each pass reduces the thickness of the plate by a substantially constant thickness amount to form the foil.

Validation of the MCNP6 electron-photon transport algorithm: multiple-scattering of 13- and 20-MeV electrons in thin foils

NASA Astrophysics Data System (ADS)

Dixon, David A.; Hughes, H. Grady

2017-09-01

This paper presents a validation test comparing angular distributions from an electron multiple-scattering experiment with those generated using the MCNP6 Monte Carlo code system. In this experiment, a 13- and 20-MeV electron pencil beam is deflected by thin foils with atomic numbers from 4 to 79. To determine the angular distribution, the fluence is measured down range of the scattering foil at various radii orthogonal to the beam line. The characteristic angle (the angle for which the max of the distribution is reduced by 1/e) is then determined from the angular distribution and compared with experiment. Multiple scattering foils tested herein include beryllium, carbon, aluminum, copper, and gold. For the default electron-photon transport settings, the calculated characteristic angle was statistically distinguishable from measurement and generally broader than the measured distributions. The average relative difference ranged from 5.8% to 12.2% over all of the foils, source energies, and physics settings tested. This validation illuminated a deficiency in the computation of the underlying angular distributions that is well understood. As a result, code enhancements were made to stabilize the angular distributions in the presence of very small substeps. However, the enhancement only marginally improved results indicating that additional algorithmic details should be studied.

Load regulating expansion fixture

DOEpatents

Wagner, Lawrence M.; Strum, Michael J.

1998-01-01

A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.

Ion acceleration from thin foil and extended plasma targets by slow electromagnetic wave and related ion-ion beam instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulanov, S. V.; A. M. Prokhorov Institute of General Physics RAS, Moscow, 119991; Esirkepov, T. Zh.

When ions are accelerated by the radiation pressure of a laser pulse, their velocity cannot exceed the pulse group velocity which can be considerably smaller than the speed of light in vacuum. This is demonstrated in two cases corresponding to a thin foil target irradiated by high intensity laser light and to the hole boring produced in an extended plasma by the laser pulse. It is found that the beams of accelerated ions are unstable against Buneman-like and Weibel-like instabilities which results in the broadening of the ion energy spectrum.

Deposition of thin insulation layers from the gas phase

NASA Technical Reports Server (NTRS)

Behn, R.; Hagedorn, H.; Kammermaier, J.; Kobale, M.; Packonik, H.; Ristow, D.; Seebacher, G.

1981-01-01

The continuous deposition of thin organic dielectric films on metallized carrier foils by glow discharge in monomeric gases is described. Depending on the applied monomers, the films had a dissipation factor of .001 to .003 (1 kHz), a relative permittivity of 2.3 to 2.5 and a resistivity of about 10 to the 17th power omega cm. Additionally, they proved to have a high mechanical homogeneity. Self-healing rolled capacitors with a very high capacitance per volume and of consistently high quality were fabricated from the metallized carrier foils covered with the dielectric film.

High conductance surge cable

DOEpatents

Murray, Matthew M.; Wilfong, Dennis H.; Lomax, Ralph E.

1998-01-01

An electrical cable for connecting transient voltage surge suppressers to ectrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation.

High conductance surge cable

DOEpatents

Murray, M.M.; Wilfong, D.H.; Lomax, R.E.

1998-12-08

An electrical cable for connecting transient voltage surge suppressors to electrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation. 6 figs.

Angular distributions of reflected and refracted relativistic electron beams crossing a thin planar target at a small angle to its surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serov, A. V., E-mail: serov@x4u.lebedev.ru; Mamonov, I. A.; Kol’tsov, A. V., E-mail: koltsov@x4u.lebedev.ru

2015-10-15

The scattering of electrons by aluminum, copper, and lead foils, as well as by bimetallic aluminum-lead and aluminum-copper foils, has been studied experimentally. A microtron with an energy of particles of 7.4 MeV has been used as a source of electrons. The beam of particles incident on a target at small angles is split into particles reflected from the foil, which constitute a reflected beam, and particles crossing the foil, which constitute a refracted beam. The effect of the material and thickness of the foil, as well as the angle between the initial trajectory of the beam and the planemore » of the target, on the direction of motion and the angular divergence of the beam crossing the foil and the beam reflected from the foil has been analyzed. Furthermore, the effect of the sequence of metal layers in bimetallic films on the angles of refraction and reflection of the beam has been examined.« less

Evidence for Coincident Fusion Products Using Silicon Surface-barrier Detectors

NASA Astrophysics Data System (ADS)

Jones, Steven; Scott, Mark; Keeney, Frank

2002-10-01

We report experimental results showing coincident proton and triton production from the reaction: d + d --> t (1.01 MeV) + p (3.02 MeV). Partially-deuterided thin titanium foils were positioned between two silicon surface-barrier detectors which were mounted in a small cylindrical vacuum chamber which also served as a Faraday cage. We performed Monte Carlo studies using the SRIM code to determine the expected energies of arriving particles after they exit the host foil. The dual-coincidence requirement reduces background to very low levels so that low yields from very thin TiD foils can be readily detected. In one sequence of experiments, we observed 74 foreground coincidences in the regions of interest compared with 24 background counts; the statistical significance is approximately ten standard deviations. A striking advance is that the repeatability from the dual-coincidence experiments is currently greater than 70%.

Thin plastic foil X-ray optics with spiral geometry

NASA Astrophysics Data System (ADS)

Barbera, Marco; Mineo, Teresa; Perinati, Emanuele; Schnopper, Herbert W.; Taibi, Angelo

2007-09-01

Winding a plastic foil ribbon into spiral cylinder or spiral cones we can design and build single or multiple reflection X-ray grazing incidence focusing optics with potential applications in Astronomy as well as experimental physics. The use of thin plastic foils from common industrial applications and of a mounting technique which does not require the construction of mandrels make these optics very cost effective. A spiral geometry focusing optic produces an annular image of a point source with the angular size of the annulus depending mainly on the pitch of the winding and the focal length. We use a ray-tracing code to evaluate the performances of cylindrical, and double conical spiral geometry as a function of the design parameters e.g. focal length, diameter, optic length. Some preliminary results are presented on X-ray imaging tests performed on spiral cylindrical optics.

X-ray mirror prototype based on cold shaping of thin glass foils

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Pareschi, Giovanni; Salmaso, Bianca; Vecchi, Gabriele; Burwitz, Vadim; Pelliciari, Carlo; Hartner, Gisela D.; Breunig, Elias

2017-08-01

The Slumping Glass Optics technology for the fabrication of astronomical X-ray mirrors has been developed in recent years in USA and Europe. The process has been used for making the mirrors of the Nustar, mission. The process starts with very thin glass foils hot formed to copy the profile of replication moulds. At INAF - Osservatorio Astronomico di Brera a process based on cold shaping is being developed, based on an integration method involving the use of interconnecting ribs for making stacks. Each glass foil in the stack is shaped onto a very precise integration mould and the correct shape is frozen by means of glued ribs that act as spacers between one layer and the next one (the first layers being attached to a thick substrate). Therefore, the increasing availability of flexible glass foils with a thickness of a few tens of microns (driven by electronic market for ultra-thin displays) opens new possibilities for the fabrication of X-ray mirrors. This solution appears interesting especially for the fabrication of mirrors for hard X-rays (with energy > 10 keV) based on multilayer coatings, taking advantage from the intrinsic low roughness of the glass foils that should grant a low scattering level. The stress frozen on the glass due to the cold shaping is not negligible, but it is kept into account in the errors of the X-ray optics design. As an exercise, we have considered the requirements and specs of the FORCE hard Xray mission concept (being studied by JAXA) and we have designed the mirror modules assuming the cold slumping as a fabrication method. In the meantime, a prototype (representative of the FORCE mirror modules) is being design and integrated in order to demonstrate the feasibility and the capacity to reach good angular resolution.

A polymer/semiconductor write-once read-many-times memory

NASA Astrophysics Data System (ADS)

Möller, Sven; Perlov, Craig; Jackson, Warren; Taussig, Carl; Forrest, Stephen R.

2003-11-01

Organic devices promise to revolutionize the extent of, and access to, electronics by providing extremely inexpensive, lightweight and capable ubiquitous components that are printed onto plastic, glass or metal foils. One key component of an electronic circuit that has thus far received surprisingly little attention is an organic electronic memory. Here we report an architecture for a write-once read-many-times (WORM) memory, based on the hybrid integration of an electrochromic polymer with a thin-film silicon diode deposited onto a flexible metal foil substrate. WORM memories are desirable for ultralow-cost permanent storage of digital images, eliminating the need for slow, bulky and expensive mechanical drives used in conventional magnetic and optical memories. Our results indicate that the hybrid organic/inorganic memory device is a reliable means for achieving rapid, large-scale archival data storage. The WORM memory pixel exploits a mechanism of current-controlled, thermally activated un-doping of a two-component electrochromic conducting polymer.

Cost-Effective TiAl based Materials

NASA Technical Reports Server (NTRS)

Moxson, V. S.; Sun, Fusheng; Draper, Susan L.; Froes, F. H.; Duz, V.

2003-01-01

Because of their inherent low ductility, TiAl-based materials are difficult to fabricate, especially thin gage titanium gamma aluminide (TiAl) sheet and foil. In this paper, an innovative powder metallurgy approach for producing cost-effective thin gage TiAl sheets (with 356 mm long and 235 mm wide, and a thickness of 0.74, 1.09, 1.55, and 2.34 mm, respectively) is presented. The microstructures and tensile properties at room and elevated temperatures of the thin gage TiAl are studied. Results show that these TiAl sheets have a relatively homogenous chemistry, uniform microstructure, and acceptable mechanical properties. This work demonstrates a cost-effective method for producing both flat products (sheet/foil) and complex chunky parts of TiAl for various advanced applications including aerospace and automotive industries.

MULPEX: A compact multi-layered polymer foil collector for micrometeoroids and orbital debris

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MUlti- Layer Polymer EXperiment (MULPEX) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 and 40 μm) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 μm olivine) and space debris (4 μm alumina and 1 mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

MULPEX: a compact multi-layered polymer foil collector for micrometeoroids and orbital debris.

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MULPEX (MUlti-Layer Polymer EXperiment) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 micron and 40 micron) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 micron olivine) and space debris (4 micron alumina and 1mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

Photon bubbles and ion acceleration in a plasma dominated by the radiation pressure of an electromagnetic pulse.

PubMed

Pegoraro, F; Bulanov, S V

2007-08-10

The stability of a thin plasma foil accelerated by the radiation pressure of a high intensity electromagnetic (e.m.) pulse is investigated analytically and with particle in cell numerical simulations. It is shown that the onset of a Rayleigh-Taylor-like instability can lead to transverse bunching of the foil and to broadening of the energy spectrum of fast ions. The use of a properly tailored e.m. pulse with a sharp intensity rise can stabilize the foil acceleration.

Fabrication of rippled surfaces for diffraction gratings by plastic deformation of platinum foils and metallic glasses

NASA Astrophysics Data System (ADS)

Korsukov, V. E.; Malygin, G. A.; Korsukova, M. M.; Nyapshaev, I. A.; Obidov, B. A.

2015-12-01

Thin platinum foils and metallic glass ribbons with a fractal surface consisting of different-scale unidirectionally oriented ripples have been fabricated using special thermoplastic processing. The general fractal dimension of the rippled surface and dimensions along and across the ripples have been measured. The optical spectra of a PRK-4 lamp using rippled Pt(111) foils as reflective diffraction gratings have been determined. A model describing the mechanism of the formation of surface unidirectional fractal structures during deformation has been proposed.

Electric current heating calibration of a laser holographic nondestructive test system

NASA Technical Reports Server (NTRS)

Liu, H.-K.; Kurtz, R. L.

1975-01-01

Holographic NDT was used to measure small surface displacements controlled by electric heating by detecting the difference of the interference fringe patterns as viewed through the hologram on a real time basis. A perforated aluminum test plate, with the holes used to position thin metal foils, was used in the experiment. One of the foils was connected to an electric power source and small displacements of the foil were caused and controlled by Ohmic heating. An He-Ne laser was used to perform the holography.

Effects of the foil flatness on irradiation performance of U10Mo monolithic mini-plates

DOE PAGES

Ozaltun, Hakan; Medvedev, Pavel G.; Rabin, Barry H.

2015-09-03

Monolithic plate-type fuels comprise of a high density, low enrichment, U10Mo fuel foil encapsulated in a cladding material. This concept generates several fabrication challenges such as flatness, centering or thickness variation. There are concerns, if these parameters have implications on overall performance. To investigate these inquiries, the effects of the foil flatness were studied. For this, a representative plate was simulated for an ideal case. The simulations were repeated for additional cases with various foil curvatures to evaluate the effects on the irradiation performance. The results revealed that the stresses and strains induced by fabrication process are not affected bymore » the flatness of the foil. Furthermore, fabrication stresses in the foil are relieved relatively fast in the reactor. The effects of the foil flatness on peak irradiation stressstrains are minimal. There is a slight increase in temperature for the case with maximum curvature. The major impact is on the displacement characteristics. Furthermore, while the case with a flat foil produces a symmetrical swelling, if the foil is curved, more swelling occurs on the thin-cladding side and the plate bows during irradiation.« less

Study on Silver-plated Molybdenum Interconnected Materials for LEO Solar Cell Array

NASA Astrophysics Data System (ADS)

Zhu, Jia-jun; Hu, Yu-hao; Xu, Meng; Yang, Wu-lin; Fu, Li-cai; Li, De-yi; Zhou, Ling-ping

2017-09-01

Atomic oxygen (AO) is one of the most important environmental factors that affected the performance of low earth orbit spacecraft in orbit. In which, silver was the most common materials as the interconnected materials. However, with the poor AO resistance of silver, the interconnectors could be failure easier, and the lifetime of the spacecraft was also reduced. In this paper, the silver-plated molybdenum interconnected materials made by Ag thin films deposited on the Mo foils by vacuum deposition methods was studied. And the effects of the preparation process on the micro-structure of the Ag thin films, the interfacial adhesive strength and the electrical conductivity of the composites were investigated. It was found that the Ag thin films deposited on the Mo substrates coated the Ag thin films by ion beam assisted deposition(IBAD) methods exhibited a perfectly (200) preferred orientation. The interfacial adhesive strength had been increased to 18.58MPa. And the composites also have excellent electrical performance.

Load regulating expansion fixture

DOEpatents

Wagner, L.M.; Strum, M.J.

1998-12-15

A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.

Fission fragment assisted reactor concept for space propulsion: Foil reactor

NASA Technical Reports Server (NTRS)

Wright, Steven A.

1991-01-01

The concept is to fabricate a reactor using thin films or foils of uranium, uranium oxide and then to coat them on substrates. These coatings would be made so thin as to allow the escaping fission fragments to directly heat a hydrogen propellant. The idea was studied of direct gas heating and direct gas pumping in a nuclear pumped laser program. Fission fragments were used to pump lasers. In this concept two substrates are placed opposite each other. The internal faces are coated with thin foil of uranium oxide. A few of the advantages of this technology are listed. In general, however, it is felt that if one look at all solid core nuclear thermal rockets or nuclear thermal propulsion methods, one is going to find that they all pretty much look the same. It is felt that this reactor has higher potential reliability. It has low structural operating temperatures, very short burn times, with graceful failure modes, and it has reduced potential for energetic accidents. Going to a design like this would take the NTP community part way to some of the very advanced engine designs, such as the gas core reactor, but with reduced risk because of the much lower temperatures.

Influence of barrier absorption properties on laser patterning thin organic films

NASA Astrophysics Data System (ADS)

Naithani, Sanjeev; Mandamparambil, Rajesh; van Assche, Ferdie; Schaubroeck, David; Fledderus, Henri; Prenen, An; Van Steenberge, Geert; Vanfleteren, Jan

2012-06-01

This paper presents a study of selective ablation of thin organic films (LEP- Light Emitting Polymer, PEDOT:PSS- Poly 3,4-ethylenedioxythiophene: polystyrene sulfonate) by using 248 nm Excimer laser, on various kinds of multilayered SiN barrier foils for the development of Organic Light Emitting Diodes (OLED). Different Silicon Nitride (SiN) barrier foils with dedicated absorption spectra are taken into account for this purpose. The drive for looking into different types of SiN originates from the fact that the laser selective removal of a polymer without damage to the barrier layer underneath is challenging in the dynamic laser processing of thin films. The barrier is solely responsible for the proper encapsulation of the OLED stack. The main limitation of current OLED design is its shorter life span, which is directly related to the moisture or water permeation into the stack, leading to black spots. An optimization of laser parameters like fluence and number of shots has been carried out for the various types of SiN barrier foils. We are able to obtain a wider working process window for the selective removal of LEP and PEDOT:PSS from SiN barrier, by variation of the different types of SiN.

Number distribution of emitted electrons by MeV H+ impact on carbon

NASA Astrophysics Data System (ADS)

Ogawa, H.; Koyanagi, Y.; Hongo, N.; Ishii, K.; Kaneko, T.

2017-09-01

The statistical distributions of the number of the forward- and backward-emitted secondary electrons (SE's) from a thin carbon foil have been measured in coincidence with foil-transmitted H+ ions of 0.5-3.0 MeV in every 0.5 MeV step. The measured SE energy spectra were fitted by assuming a Pólya distribution for the simultaneous n-SE emission probabilities. For our previous data with a couple of the carbon foils with different thicknesses, a similar analysis has been carried out. As a result, it was found that the measured spectra could be reproduced as well as by an analysis without placing any restriction on the emission probabilities both for the forward and backward SE emission. The obtained b-parameter of the Pólya distribution, which is a measure of the deviation from a Poisson distribution due to the cascade multiplication by high energy internal SE's, increases monotonically with the incident energy of proton beams. On the other hand, a clear foil-thickness dependence is not observed for the b-parameter. A theoretical model which could reproduced the magnitude of the b-parameter for the SE energy spectra obtained with thick Au, Cu and Al targets is found to overestimates our values for thin carbon foils significantly. Another model calculation is found to reproduce our b-values very well.

In-line beam current monitor

DOEpatents

Ekdahl, Jr., Carl A.; Frost, Charles A.

1986-01-01

An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

In-line beam current monitor

DOEpatents

Ekdahl, C.A. Jr.; Frost, C.A.

1984-11-13

An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

Flying-plate detonator using a high-density high explosive

DOEpatents

Stroud, John R.; Ornellas, Donald L.

1988-01-01

A flying-plate detonator containing a high-density high explosive such as benzotrifuroxan (BTF). The detonator involves the electrical explosion of a thin metal foil which punches out a flyer from a layer overlying the foil, and the flyer striking a high-density explosive pellet of BTF, which is more thermally stable than the conventional detonator using pentaerythritol tetranitrate (PETN).

How Thin Is Foil? Applying Density to Find the Thickness of Aluminum Foil

ERIC Educational Resources Information Center

Concannon, James P.

2011-01-01

In this activity, I show how high school students apply their knowledge of density to solve an unknown variable, such as thickness. Students leave this activity with a better understanding of density, the knowledge that density is a characteristic property of a given substance, and the ways density can be measured. (Contains 4 figures and 1 table.)

Creep analysis of solid oxide fuel cell with bonded compliant seal design

NASA Astrophysics Data System (ADS)

Jiang, Wenchun; Zhang, Yucai; Luo, Yun; Gong, J. M.; Tu, S. T.

2013-12-01

Solid oxide fuel cell (SOFC) requires good sealant because it works in harsh conditions (high temperature, thermal cycle, oxidative and reducing gas environments). Bonded compliant seal (BCS) is a new sealing method for planar SOFC. It uses a thin foil metal to bond the window frame and cell, achieving the seal between window frame and cell. At high temperature, a comprehensive evaluation of its creep strength is essential for the adoption of BCS design. In order to characterize the creep behavior, the creep induced by thermal stresses in SOFC with BCS design is simulated by finite element method. The results show that the foil is compressed and large thermal stresses are generated. The initial peak thermal stress is located in the thin foil because the foil acts as a spring stores the thermal stresses by elastic and plastic deformation in itself. Serving at high temperature, initial thermal displacement is partially recovered because of the creep relaxation, which becomes a new discovered advantage for BCS design. It predicts that the failures are likely to happen in the middle of the cell edge and BNi-2 filler metal, because the maximum residual displacement and creep strain are located.

Evaluation of selected thermal control coatings for long-life space structures

NASA Technical Reports Server (NTRS)

Teichman, Louis A.; Slemp, Wayne S.; Witte, William G., Jr.

1992-01-01

Graphite-reinforced resin matrix composites are being considered for spacecraft structural applications because of their light weight, high stiffness, and lower thermal expansion. Thin protective coatings with stable optical properties and the proper ratio of solar absorption (alpha sub s) to thermal emittance (epsilon) minimize orbital thermal extremes and protect these materials against space environment degradation. Sputtered coatings applied directly to graphite/epoxy composite surfaces and anodized coatings applied to thin aluminum foil were studied for use both as an atomic oxygen barrier and as thermal control coatings. Additional effort was made to develop nickel-based coatings which could be applied directly to composites. These coating systems were selected because their inherent tenacity made them potentially more reliable than commercial white paints for long-life space missions. Results indicate that anodized aluminum foil coatings are suitable for tubular and flat composite structures on large platforms in low Earth orbit. Anodized foil provides protection against some elements of the natural space environment (atomic oxygen, ultraviolet, and particulate radiation) and offers a broad range of tailored alpha sub s/epsilon. The foil is readily available and can be produced in large quantities, while the anodizing process is a routine commercial technique.

The BiPo-3 detector for the measurement of ultra low natural radioactivities of thin materials

NASA Astrophysics Data System (ADS)

Barabash, A. S.; Basharina-Freshville, A.; Birdsall, E.; Blondel, S.; Blot, S.; Bongrand, M.; Boursette, D.; Brudanin, V.; Busto, J.; Caffrey, A. J.; Calvez, S.; Cascella, M.; Cebrián, S.; Cerna, C.; Cesar, J. P.; Chauveau, E.; Chopra, A.; Dafní, T.; De Capua, S.; Duchesneau, D.; Durand, D.; Egorov, V.; Eurin, G.; Evans, J. J.; Fajt, L.; Filosofov, D.; Flack, R.; Garrido, X.; Gómez, H.; Guillon, B.; Guzowski, P.; Holý, K.; Hodák, R.; Huber, A.; Hugon, C.; Iguaz, F. J.; Irastorza, I. G.; Jeremie, A.; Jullian, S.; Kauer, M.; Klimenko, A.; Kochetov, O.; Konovalov, S. I.; Kovalenko, V.; Lang, K.; Lemière, Y.; Le Noblet, T.; Liptak, Z.; Liu, X. R.; Loaiza, P.; Lutter, G.; Luzón, G.; Macko, M.; Mamedov, F.; Marquet, C.; Mauger, F.; Morgan, B.; Mott, J.; Nemchenok, I.; Nomachi, M.; Nova, F.; Ohsumi, H.; Oliviéro, G.; Ortiz de Solórzano, A.; Pahlka, R. B.; Pater, J.; Perrot, F.; Piquemal, F.; Povinec, P.; Přidal, P.; Ramachers, Y. A.; Remoto, A.; Richards, B.; Riddle, C. L.; Rukhadze, E.; Saakyan, R.; Salazar, R.; Sarazin, X.; Shitov, Yu.; Simard, L.; Šimkovic, F.; Smetana, A.; Smolek, K.; Smolnikov, A.; Söldner-Rembold, S.; Soulé, B.; Štekl, I.; Thomas, J.; Timkin, V.; Torre, S.; Tretyak, Vl. I.; Tretyak, V. I.; Umatov, V. I.; Vilela, C.; Vorobel, V.; Waters, D.; Žukauskas, A.

2017-06-01

The BiPo-3 detector, running at the Canfranc Underground Laboratory (Laboratorio Subterr&aposaneo de Canfranc, LSC, Spain) since 2013, is a low-radioactivity detector dedicated to measuring ultra low natural radionuclide contaminations of 208Tl (232Th chain) and 214Bi (238U chain) in thin materials. The total sensitive surface area of the detector is 3.6 m2. The detector has been developed to measure the radiopurity of the selenium double β-decay source foils of the SuperNEMO experiment. In this paper the design and performance of the detector, and results of the background measurements in 208Tl and 214Bi, are presented, and the validation of the BiPo-3 measurement with a calibrated aluminium foil is discussed. Results of the 208Tl and 214Bi activity measurements of the first enriched 82Se foils of the double β-decay SuperNEMO experiment are reported. The sensitivity of the BiPo-3 detector for the measurement of the SuperNEMO 82Se foils is Script A(208Tl) <2 μBq/kg (90% C.L.) and Script A(214Bi) <140 μBq/kg (90% C.L.) after 6 months of measurement.

Slumped glass foils as substrate for adjustable x-ray optics

NASA Astrophysics Data System (ADS)

Salmaso, Bianca; Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Pelliciari, Carlo; Spiga, Daniele; Vecchi, Gabriele; Pareschi, Giovanni

2016-09-01

Thin glass modular mirrors are a viable solution to build future X-ray telescopes with high angular resolution and large collecting area. In our laboratories, we shape thin glass foils by hot slumping and we apply pressure to assist the replication of a cylindrical mould figure; this technology is coupled with an integration process able to damp low frequency errors and produces optics in the Wolter I configuration, typical for the X-ray telescopes. From the point of view of the hot slumping process, the efforts were focused in reducing low-, mid- and high- frequency errors of the formed Eagle glass foils. Some of our slumped glass foils were used for the development of active X-ray optics, where piezoelectric actuators are used to correct the slumped glass foil deviations from the ideal shape. In particular, they were used for the Adjustable X-raY optics for astrOnoMy project (AXYOM) developed in Italy, and the X-ray Surveyor mission, as developed at the Smithsonian Astrophysical Observatory / Center for Astrophysics (SAO/CfA) in USA. In this paper we describe the optimisation of the hot slumping process, comparing the results with the requirements of the considered active optics projects. Finally, since the present configuration of the Pennsylvania State University (PSU) coating equipment is limited to 100 x 100 mm2, the slumped glass foils used for the SAO project were cut from 200 x 200 mm2 to 100 x 100 mm2, and a low-frequency change was observed. A characterisation of the profile change upon cutting is presented.

Explosive-driven, high speed, arcless switch

DOEpatents

Skogmo, P.J.; Tucker, T.J.

1986-05-02

An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed.

Explosive-driven, high speed, arcless switch

DOEpatents

Skogmo, Phillip J.; Tucker, Tillman J.

1987-01-01

An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed.

Resistence seam welding thin copper foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollar, D.L. Jr.

1991-02-01

Use of flat flexible circuits in the electronics industry is expanding. The term flexible circuits'' is defined here as copper foil which has been bonded to an insulating film such as Kapton film. The foil is photo processed to produce individual circuit paths similar to printed circuit boards. Another insulating film is laminated over the conductors to complete the flexible circuit. Flexible circuits, like multiwire cables, are susceptible to electromagnetic radiation (EMR) interference. On multiwire cables the interference problem is mitigated by adding a woven wire braid shielding over the conductors. Shielding on flexible circuits is accomplished by enclosing themore » circuits in a copper foil envelope. However, the copper foil must be electrically sealed around the flexcircuit to be effective. Ultimately, a resistance seam welding process and appropriate equipment were developed which would provide the required electrical seal between two layers of 2-oz (0.0028-inch thick) copper foil on a 1.1-inch wide, 30-inch long, 0.040-inch thick flexible circuit. 4 refs., 19 figs.« less

Inspection of cup-shaped steel parts from the I.D. side using eddy current

NASA Astrophysics Data System (ADS)

Griffiths, Erick W.; Pearson, Lee H.

2018-04-01

An eddy current method was developed to inspect cup-shaped steel parts from the I.D. side. During the manufacturing process of these parts, a thin Al tape foil is applied to the I.D. side of the part. One of the critical process parameters is that only one foil layer can be applied. An eddy current inspection system was developed to reject parts with more than one foil layer. The Al tape foil is cut to length to fit the inner diameter, however, after application of the foil there is a gap created between the beginning and end of the foil. It was found that this gap interfered with the eddy current inspection causing a false positive indication. To solve this problem a sensor design and data analysis process were developed to overcome the effects of these gaps. The developed system incorporates simultaneous measurements from multiple eddy current sensors and signal processing to achieve a reliable inspection.

The Chevron Foil Thrust Bearing: Improved Performance Through Passive Thermal Management and Effective Lubricant Mixing

NASA Technical Reports Server (NTRS)

Bruckner, Robert

2013-01-01

An improved foil thrust bearing is described that eliminates or reduces the need for forced cooling of the bearing foils while at the same time improves the load capacity of the bearing, enhances damping, provides overload tolerance, and eliminates the high speed load capacity drop-off that plagues the current state of the art. The performance improvement demonstrated by the chevron foil thrust bearing stems from a novel trailing edge shape that splays the hot lubricant in the thin film radially, thus preventing hot lubricant carry-over into the ensuing bearing sector. Additionally, the chevron shaped trailing edge induces vortical mixing of the hot lubricant with the gas that is naturally resident within the inter-pad region of a foil thrust bearing. The elimination of hot gas carry-over in combination with the enhanced mixing has enabled a completely passive thermally managed foil bearing design. Laboratory testing at NASA has confirmed the original analysis and reduced this concept to practice.

Miniature bulge test and energy release rate in HIPed aluminum/aluminum interfacial fracture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C.; Lovato, M. L.; Clarke, K. D.

We summarize the development of a technique of using miniature bulge test combined with three-dimensional digital image correlation (3D-DIC) for measuring energy release rate or fracture toughness of bimaterial interface of thin metal foils. Furthermore, the energy release rate associated with the HIPed aluminum/aluminum interfacial delamination is determined experimentally using the proposed technique. Detailed discussions of the schemes of preparing and conducting the bulge test, and computing various quantities required for the determination of the energy release rate are presented.

Miniature bulge test and energy release rate in HIPed aluminum/aluminum interfacial fracture

DOE PAGES

Liu, C.; Lovato, M. L.; Clarke, K. D.; ...

2017-10-13

We summarize the development of a technique of using miniature bulge test combined with three-dimensional digital image correlation (3D-DIC) for measuring energy release rate or fracture toughness of bimaterial interface of thin metal foils. Furthermore, the energy release rate associated with the HIPed aluminum/aluminum interfacial delamination is determined experimentally using the proposed technique. Detailed discussions of the schemes of preparing and conducting the bulge test, and computing various quantities required for the determination of the energy release rate are presented.

The possibility of using platinum foils with a rippled surface as diffraction gratings

NASA Astrophysics Data System (ADS)

Korsukov, V. E.; Ankudinov, A. V.; Butenko, P. N.; Knyazev, S. A.; Korsukova, M. M.; Obidov, B. A.; Shcherbakov, I. P.

2014-09-01

The atomic structure and surface relief of thin cold-rolled platinum foils upon recrystallization annealing and loading under ultrahigh vacuum conditions have been studied by low energy electron diffraction (LEED), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). The surface of samples upon high-temperature annealing and subsequent uniaxial extension of recrystallized Pt foils represents a fractal structure of unidirectional ripples on various spatial scales. The total fractal dimension of this surface is D GW = 2.3, while the fractal dimensions along and across ripples are D ‖ ≈ 1 and D ⊥ ≈ 1.3, respectively. The optical spectra of a halogen lamp and a PRK-2 mercury lamp were recorded using these rippled Pt foils as reflection diffraction gratings. It is shown that Pt foils with this surface relief can be used as reflection diffraction gratings for electromagnetic radiation in a broad spectral range.

Development of Accurate Structure for Mounting and Aligning Thin-Foil X-Ray Mirrors

NASA Technical Reports Server (NTRS)

Heilmann, Ralf K.

2001-01-01

The goal of this work was to improve the assembly accuracy for foil x-ray optics as produced by the high-energy astrophysics group at the NASA Goddard Space Flight Center. Two main design choices lead to an alignment concept that was shown to improve accuracy well within the requirements currently pursued by the Constellation-X Spectroscopy X-Ray Telescope (SXT).

The stopping powers and energy straggling of heavy ions in polymer foils

NASA Astrophysics Data System (ADS)

Mikšová, R.; Macková, A.; Malinský, P.; Hnatowicz, V.; Slepička, P.

2014-07-01

The stopping power and energy straggling of 7Li, 12C and 16O ions in thin poly(etheretherketone) (PEEK), polyethylene terephthalate (PET) and polycarbonate (PC) foils were measured in the incident beam energy range of 9.4-11.8 MeV using an indirect transmission method. Ions scattered from a thin gold target at an angle of 150° were registered by a partially depleted PIPS detector, partly shielded with a polymer foil placed in front of the detector. Therefore, the signals from both direct and slowed down ions were visible in the same energy spectrum, which was evaluated by the ITAP code, developed at our laboratory. The ITAP code was employed to perform a Gaussian-fitting procedure to provide a complete analysis of each measured spectrum. The measured stopping powers were compared with the predictions obtained from the SRIM-2008 and MSTAR codes and with previous experimental data. The energy straggling data were compared with those calculated by using Bohr's, Lindhard-Scharff and Bethe-Livingston theories.

Explosive-driven, high speed, arcless switch

DOEpatents

Skogmo, P.J.; Tucker, T.J.

1987-07-14

An explosive-actuated, fast-acting arcless switch contains a highly conductive foil to carry high currents positioned adjacent a dielectric surface within a casing. At one side of the foil opposite the dielectric surface is an explosive which, when detonated, drives the conductive foil against the dielectric surface. A pattern of grooves in the dielectric surface ruptures the foil to establish a rupture path having a pattern corresponding to the pattern of the grooves. The impedance of the ruptured foil is greater than that of the original foil to divert high current to a load. Planar and cylindrical embodiments of the switch are disclosed. 7 figs.

Highly periodic laser-induced nanostructures on thin Ti and Cu foils for potential application in laser ion acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Susanta Kumar, E-mail: skdasfpy@kiit.ac.in; Andreev, Alexander; Braenzel, Julia

2016-03-21

The feasibility of femtosecond laser-induced periodic nanostructures on thin Ti and Cu foils (thickness down to 1 μm) is demonstrated. At pulse durations of 120 fs and a wavelength of 400 nm, periods of 61 nm to 320 nm were obtained. Particle-in-cell simulations of laser ion acceleration processes with such nanostructured targets indicate their potential for high energy particle physics applications. In particular, a measurable enhancement of the proton cut-off energy and a significant enhancement of the number of accelerated particles compared to non- or weakly structured targets of same thickness and material are expected.

Adapalene

MedlinePlus

... or cream, use your fingers to spread a thin film of medication over the affected area. If you are using a pledget, remove it from the foil pouch and gently wipe the affected area. If you are using the glass bottle of solution, apply a thin layer to the affected area using the applicator ...

{001} Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

NASA Astrophysics Data System (ADS)

Yeo, Hong Goo; Trolier-McKinstry, Susan

2014-07-01

Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O3 (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, {001} oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO2 grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO3 films were integrated by CSD on the HfO2 coated substrates. A high level of {001} LaNiO3 and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ˜36 μC/cm2, while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e31,f| piezoelectric coefficient was around 10.6 C/m2 for hot-poled (001) oriented PZT film on Ni.

Handheld Reflective Foil Emissometer with 0.007 Absolute Accuracy at 0.05

NASA Astrophysics Data System (ADS)

van der Ham, E. W. M.; Ballico, M. J.

2014-07-01

The development and performance of a handheld emissometer for the measurement of the emissivity of highly reflective metallic foils used for the insulation of domestic and commercial buildings are described. Reflective roofing insulation based on a thin coating of metal on a more robust substrate is very widely used in hotter climates to reduce the radiant heat transfer between the ceiling and roof in commercial and residential buildings. The required normal emissivity of these foils is generally below 0.05, so stray reflected ambient infrared radiation (IR) makes traditional reflectance-based measurements of emissivity very difficult to achieve with the required accuracy. Many manufacturers apply additional coatings onto the metallic foil to reduce visible glare during installation on a roof, and to provide protection to the thin reflective layer; however, this layer can also substantially increase the IR emissivity. The system as developed at the National Measurement Institute, Australia (NMIA) is based on the principle of measurement of the modulation in thermal infrared radiation, as the sample is thermally modulated by hot and cold air streams. A commercial infrared to band radiation thermometer with a highly specialized stray and reflected radiation shroud attachment is used as the detector system, allowing for convenient handheld field measurements. The performance and accuracy of the system have been compared with NMIA's reference emissometer systems for a number of typical material samples, demonstrating its capability to measure the absolute thermal emissivity of these very highly reflective foils with an uncertainty of better than.

Polymer gel dosimetry for measuring the dose near thin high-Z materials irradiated with high energy photon beams.

PubMed

Warmington, Leighton L; Gopishankar, N; Broadhurst, John H; Watanabe, Yoichi

2016-12-01

To investigate the feasibility of three-dimensional (3D) dose measurements near thin high-Z materials placed in a water-like medium by using a polymer gel dosimeter (PGD) when the medium was irradiated with high energy photon beams. PGD is potentially a useful tool for this application because it can record the dose around a small object made of a high-Z material in a continuous 3D medium. In this study, the authors manufactured a methacrylic acid-based normoxic PGD, nMAG. Two 0.5 mm thick lead foils (1 × 1 cm) were placed in foil supports with 0.7 cm separation in a 1000 ml polystyrene container filled with nMAG. The authors used two foil configurations, i.e., orthogonal and parallel. In the orthogonal configuration, two foils were placed in the direction orthogonal to the beam axis. The parallel configuration had two foils arranged in parallel to the beam axis. The phantom was irradiated with an 18 MV photon beam of 5 × 5 cm field size. It was imaged with a three-Tesla (3 T) magnetic resonance imaging (MRI) scanned using the Car-Purcell-Meiboom-Gill pulse sequence. The spin-spin relaxation time (R2) to-dose calibration data were obtained by using small vials filled with nMAG and exposing to known doses. The DOSXYZnrc Monte Carlo (MC) code was used to get the expected dose distributions. More than 35 × 10 6 of histories were simulated so that the average error was less than 1%. An in-house matlab-based software was used to obtain the dose distributions from the measured R2 data as well as to compare the measurements and the MC predictions. The dose change due to the presence of the foils was studied by comparing the dose distributions with and without foils (or the reference). For the orthogonal configuration, the measured dose along the beam axis showed an increase in the upstream side of the first foil, between the foils, and on the downstream side of the second foil. The range of increased dose area was 1.1 cm in the upstream of the first foil. However, in the downstream of the second foil, it was 0.2 cm, beyond which the dose fell below the reference dose by 10%. The dose profile between the foils showed a well-like shape with the minimum dose still larger than the reference dose by 1.8%. The minimum dose point was closer to the first foil than to the second foil. For the parallel configuration, the dose between foils was the largest at the center. The increased dose area opposite to the gap between foils extended outward to 1 cm. The spatial dose distributions of PGD and MC showed the same geometrical patterns except for the points inside the foils for both orthogonal and parallel foil arrangements. The authors demonstrated that the nMAG PGD with MRI could be used to measure the 3D dosimetric structures at the mm-scale in the vicinity of the foil. The current study provided more accurate 3D spatial dose distribution than the previous studies. Furthermore, the measurements were validated by the MC simulation.

Design and evaluation of thin metal surface insulation for hypersonic flight

NASA Technical Reports Server (NTRS)

Miller, R. C.; Petach, A. M.

1976-01-01

An all-metal insulation was studied as a thermal protection system for hypersonic vehicles. Key program goals included fabricating the insulation in thin packages which are optimized for high temperature insulation of an actively cooled aluminum structure, and the use of state-of-the-art alloys. The insulation was fabricated from 300 series stainless steel in thicknesses of 0.8 to 12 mm. The outer, 0.127 mm thick, skin was textured to accommodate thermal expansion and oxidized to increase emittance. The thin insulating package was achieved using an insulation concept consisting of foil radiation shields spaced within the package, and conical foil supports to carry loads from the skin and maintain package dimensions. Samples of the metal-insulation were tested to evaluate thermal insulation capability, rain and sand erosion resistance, high temperature oxidation resistance, applied load capability, and high temperature emittance.

Design and Development of Thin Plastic Foil, Conical Approximation, High Through-out X-Ray Telescope: Light Weight, Thin Plastic Foil, X-Ray Telescopes

NASA Technical Reports Server (NTRS)

Schnopper, Herbert W.; Barbera, Marco; Silver, Eric; Ingram, Russell; Christensen, Finn E.; Romaine, Suzanne; Cohen, Lester; Collura, Alfonso; Murray, Stephen S.; Brinton, John C. (Technical Monitor)

2002-01-01

We present results from a program to develop an X-ray telescope made from thin plastic shells. Our initial results have been obtained from multi-shell cylindrical lenses that are used in a point-to-point configuration to image the small focal spot of a an X-ray tube on a microchannel plate detector. We describe the steps that led up to the present design and present data from the tests that have been used to identify the properties of the plastic material that make it a suitable X-ray reflector. We discuss two applications of our technology to X-ray missions that are designed to address some of the scientific priorities set forth in NASA's long term plans for high energy astrophysics. One mission will observe in the 1 - 10 keV band, the other will extend up to ca. 100 keV.

Microstructure based procedure for process parameter control in rolling of aluminum thin foils

NASA Astrophysics Data System (ADS)

Johannes, Kronsteiner; Kabliman, Evgeniya; Klimek, Philipp-Christoph

2018-05-01

In present work, a microstructure based procedure is used for a numerical prediction of strength properties for Al-Mg-Sc thin foils during a hot rolling process. For this purpose, the following techniques were developed and implemented. At first, a toolkit for a numerical analysis of experimental stress-strain curves obtained during a hot compression testing by a deformation dilatometer was developed. The implemented techniques allow for the correction of a temperature increase in samples due to adiabatic heating and for the determination of a yield strength needed for the separation of the elastic and plastic deformation regimes during numerical simulation of multi-pass hot rolling. At the next step, an asymmetric Hot Rolling Simulator (adjustable table inlet/outlet height as well as separate roll infeed) was developed in order to match the exact processing conditions of a semi-industrial rolling procedure. At each element of a finite element mesh the total strength is calculated by in-house Flow Stress Model based on evolution of mean dislocation density. The strength values obtained by numerical modelling were found in a reasonable agreement with results of tensile tests for thin Al-Mg-Sc foils. Thus, the proposed simulation procedure might allow to optimize the processing parameters with respect to the microstructure development.

Spot size dependence of laser accelerated protons in thin multi-ion foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Tung-Chang, E-mail: tcliu@umd.edu; Shao, Xi; Liu, Chuan-Sheng

2014-06-15

We present a numerical study of the effect of the laser spot size of a circularly polarized laser beam on the energy of quasi-monoenergetic protons in laser proton acceleration using a thin carbon-hydrogen foil. The used proton acceleration scheme is a combination of laser radiation pressure and shielded Coulomb repulsion due to the carbon ions. We observe that the spot size plays a crucial role in determining the net charge of the electron-shielded carbon ion foil and consequently the efficiency of proton acceleration. Using a laser pulse with fixed input energy and pulse length impinging on a carbon-hydrogen foil, amore » laser beam with smaller spot sizes can generate higher energy but fewer quasi-monoenergetic protons. We studied the scaling of the proton energy with respect to the laser spot size and obtained an optimal spot size for maximum proton energy flux. Using the optimal spot size, we can generate an 80 MeV quasi-monoenergetic proton beam containing more than 10{sup 8} protons using a laser beam with power 250 TW and energy 10 J and a target of thickness 0.15 wavelength and 49 critical density made of 90% carbon and 10% hydrogen.« less

The Gamma-Ray Laser Project

DTIC Science & Technology

1989-10-01

rabbits, P to flat planchettes , F to metallic foils, and B to scintillation bottles. The 18Ta sample consisted of a dusting of oxide on a thin aluminum...slower class consisted either of thin metallic disks or metallic chips or chemical compounds contained within flat polyethylene planchettes . 16 N00014-86

Interband and intraband electron kinetics in non-thermal warm dense gold

NASA Astrophysics Data System (ADS)

Brennan Brown, Shaughnessy; Chen, Zhijiang; Curry, Chandra; Hering, Philippe; Hoffmann, Matthias C.; Ng, Andrew; Reid, Matthew; Tsui, Ying Y.; Glenzer, Siegfried H.

2015-11-01

Single-state warm dense matter may be produced via isochoric heating of thin metal foils using ultrafast high-power lasers. Previous experiments have confirmed that electron temperatures exceed ion temperatures during the initial picoseconds following excitation; however, electron kinetics in non-thermal states preceding establishment of a well-defined electron thermal distribution remain little understood. X-ray and optical probing techniques provide necessary resolution to investigate these electronic properties. Here, we will present a study of electron kinetics in warm dense gold produced by irradiating free-standing 30 nm Au foils with a 400 nm FWHM, 45 fs Ti:Sapphire laser system at SLAC National Accelerator Laboratory. The temporal evolutions of AC conductivity for 400 nm and 800 nm laser pulses are simultaneously determined with sub-100 fs resolution, providing insight into the 5 d-6 s/ p interband and 6 s / p intraband transitions respectively. Our results suggest that Auger decay and three-body recombination play important roles in electron thermalization of warm dense gold.

High strain rate metalworking with vaporizing foil actuator: Control of flyer velocity by varying input energy and foil thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vivek, A., E-mail: vivek.4@osu.edu; Hansen, S. R.; Daehn, Glenn S.

2014-07-15

Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Dopplermore » velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.« less

Battery plate containing filler with conductive coating

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1986-01-01

The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

Battery plate containing filler with conductive coating

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1985-01-01

The plate (10) comprises a matrix or binder resin phase (12) in which is dispersed particulate, conductive tin oxide such as tin oxide coated glass fibers (14). A monopolar plate (11) is prepared by coating a layer (18) of electrolytically active material onto a surface of the plate (10). Tin oxide is prevented from reduction by coating a surface of the plate (10) with a conductive, impervious layer resistant to reduction such as a thin film (22) of lead adhered to the plate with a layer (21) of conductive adhesive. The plate (10) can be formed by casting a molten dispersion from mixer (36) onto a sheet (30) of lead foil or by passing an assembly of a sheet (41) of resin, a sheet (43) of fiberglass and a sheet (45) of lead between the nip of heated rollers (48, 50).

Analytical model for release calculations in solid thin-foils ISOL targets

NASA Astrophysics Data System (ADS)

Egoriti, L.; Boeckx, S.; Ghys, L.; Houngbo, D.; Popescu, L.

2016-10-01

A detailed analytical model has been developed to simulate isotope-release curves from thin-foils ISOL targets. It involves the separate modeling of diffusion and effusion inside the target. The former has been modeled using both first and second Fick's law. The latter, effusion from the surface of the target material to the end of the ionizer, was simulated with the Monte Carlo code MolFlow+. The calculated delay-time distribution for this process was then fitted using a double-exponential function. The release curve obtained from the convolution of diffusion and effusion shows good agreement with experimental data from two different target geometries used at ISOLDE. Moreover, the experimental yields are well reproduced when combining the release fraction with calculated in-target production.

Laser energy transformation to shock waves in multi-layer flyers

NASA Astrophysics Data System (ADS)

Kasperczuk, A.; Pisarczyk, T.; Gus'kov, S. Yu.; Ullschmied, J.; Krouský, E.; Masek, K.; Pfeifer, M.; Rohlena, K.; Skala, J.; Kalal, M.; Tikhonchuk, V.; Pisarczyk, P.

Investigations of powerful laser pulse action on planar flyer targets consisting of the layers of different materials are of importance from the basic as well as the applied physics point of view. One important aspect of this research deals with optimization of inertial fusion targets design. Here, the role of a thin heavy metal layer as a protector against preliminary heating of compressed thermonuclear fuel by thermal X-ray radiation can be mentioned as one particular topic to be properly understood. In this paper, the results of our studies of such a thin layer influence on the laser-produced energy deposition in the flyer foils as well as on the hydrodynamic motion of the foils as a hole will be reported. A 0.4 μ m thick gold layer was located between an aluminum layer of 6 μ m thickness and mylar layer with thickness of 2.5 μ m, used here as an ablator. For comparison, the flyer target without the gold layer but of the same area density was employed. Two different target constructions were used: (1) with a 2 mm gap separating the foil and the massive targets for measuring the foil velocity and (2) with gaps of 50, 100 and 200 μ m for laser energy transfer efficiency measurements. Targets were irradiated by laser beam energies of ˜100 J in the case of the first harmonic, and by laser beam energies ˜120 J in the case of the third one using the Prague Asterix Laser System iodine laser. The interaction spot radius of 200 μ m and the laser pulse duration of ˜250 ps were employed in these experiments. A three-frame interferometric and shadowgraphic system was set-up as to measure velocities of the rear side of the foils and to determine electron density distributions at different stages of plasma evolution. Volumes of craters produced by collisions of accelerated foils with a massive aluminum block were used as an indicator of the laser energy transfer efficiency into the foils of both types. These experiments have shown that the presence of the thin gold layer causes a decrease of the flyer velocity by a factor of ˜1.2 for both the harmonics. However, in the case of the first harmonic, the energy transfer into the flyer with the gold layer is higher (compared with the flyers without the gold layer) only for the targets with smaller gaps. In the case of the third harmonic, about 10% decrease in the amount of energy transferred into the foil with the gold layer was observed.

Multiple-foil microabrasion package (A0023)

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Ashworth, D. G.; Carey, W. C.; Flavill, R. P.; Jennison, R. C.

1984-01-01

The specific scientific objectives of this experiment are to measure the spatial distribution, size, velocity, radiance, and composition of microparticles in near-Earth space. The technological objectives are to measure erosion rates resulting from microparticle impacts and to evaluate thin-foil meteor 'bumpers'. The combinations of sensitivity and reliability in this experiment will provide up to 1000 impacts per month for laboratory analysis and will extend current sensitivity limits by 5 orders of magnitude in mass.

Thin, Light, Flexible Heaters Save Time and Energy

NASA Technical Reports Server (NTRS)

2007-01-01

The Icing Branch at NASA's Glenn Research Center uses the Center's Icing Research Tunnel (IRT) and Icing Research Aircraft to research methods for evaluating and simulating the growth of ice on aircraft, the effects that ice may have on aircraft in flight, and the development and effectiveness of various ice protection and detection systems. EGC Enterprises Inc. (EGC), of Chardon, Ohio, used the IRT to develop thermoelectric thin-film heater technology to address in-flight icing on aircraft wings. Working with researchers at Glenn and the original equipment manufacturers of aircraft parts, the company tested various thin, flexible, durable, lightweight, and efficient heaters. Development yielded a thin-film heater technology that can be used in many applications in addition to being an effective deicer for aircraft. This new thermoelectric heater was dubbed the QoFoil Rapid Response Thin-Film Heater, or QoFoil, for short. The product meets all criteria for in-flight use and promises great advances in thin-film, rapid response heater technology for a broad range of industrial applications. Primary advantages include time savings, increased efficiency, and improved temperature uniformity. In addition to wing deicing, EGC has begun looking at the material's usefulness for applications including cooking griddles, small cabinet heaters, and several laboratory uses.

Automated Composites Processing Technology: Film Module

NASA Technical Reports Server (NTRS)

Hulcher, A. Bruce

2004-01-01

NASA's Marshall Space Flight Center (MSFC) has developed a technology that combines a film/adhesive laydown module with fiber placement technology to enable the processing of composite prepreg tow/tape and films, foils or adhesives on the same placement machine. The development of this technology grew out of NASA's need for lightweight, permeation-resistant cryogenic propellant tanks. Autoclave processing of high performance composites results in thermally-induced stresses due to differences in the coefficients of thermal expansion of the fiber and matrix resin components. These stresses, together with the reduction in temperature due to cryogen storage, tend to initiate microcracking within the composite tank wall. One way in which to mitigate this problem is to introduce a thin, crack-resistant polymer film or foil into the tank wall. Investigation into methods to automate the processing of thin film or foil materials into composites led to the development of this technology. The concept employs an automated film supply and feed module that may be designed to fit existing fiber placement machines, or may be designed as integral equipment to new machines. This patent-pending technology can be designed such that both film and foil materials may be processed simultaneously, leading to a decrease in part build cycle time. The module may be designed having a compaction device independent of the host machine, or may utilize the host machine's compactor. The film module functions are controlled by a dedicated system independent of the fiber placement machine controls. The film, foil, or adhesive is processed via pre-existing placement machine run programs, further reducing operational expense.

The stopping power and energy straggling of the energetic C and O ions in polyimide

NASA Astrophysics Data System (ADS)

Mikšová, R.; Macková, A.; Slepička, P.

2016-03-01

The stopping power and energy straggling of 12Cn+ and 16On+ heavy ions in the energy range 5.3-8.0 MeV in 8 μm thick polyimide (PI) foil were measured by means of an indirect transmission method using a half-covered a PIPS detector. Ions scattered from thin gold layer, under the scattering angle 150° were detected and the spectrum of ions penetrating the PI foil and without foil was recorded. The values of the experimentally determined stopping powers were compared to the calculated data by SRIM-2013 and MSTAR codes. Measured data were in good agreement with data calculated by SRIM-2013, especially for C ions was observed better agreement than for O ions. The energy straggling was determined and compared to those calculated by using Bohr's, Bethe-Livingston and Yang models. The measured energy straggling values in the PI foil was corrected for foil roughness and thickness inhomogeneity determined from AFM. Bethe-Livingston predicting formula has been modified to make it appropriate for thicker targets. The energy straggling determined in our experiment was obtained higher than Bohr's predicted value; the predictions by Yang are in good agreement with our experiment. Bethe-Livingston formulation of the energy straggling shows better agreement with the experimental data after the modified formula implementation which assumes that the thick target was consisted to be composed of n-number of thin layers. Influence of the charge-exchange phenomena to the energy straggling of C and O ions in PI was discussed.

Flying mirror model for interaction of a super-intense laser pulse with a thin plasma layer: Transparency and shaping of linearly polarized laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulagin, Victor V.; Cherepenin, Vladimir A.; Hur, Min Sup

2007-11-15

A self-consistent one-dimensional (1D) flying mirror model is developed for description of an interaction of an ultra-intense laser pulse with a thin plasma layer (foil). In this model, electrons of the foil can have large longitudinal displacements and relativistic longitudinal momenta. An approximate analytical solution for a transmitted field is derived. Transmittance of the foil shows not only a nonlinear dependence on the amplitude of the incident laser pulse, but also time dependence and shape dependence in the high-transparency regime. The results are compared with particle-in-cell (PIC) simulations and a good agreement is ascertained. Shaping of incident laser pulses usingmore » the flying mirror model is also considered. It can be used either for removing a prepulse or for reducing the length of a short laser pulse. The parameters of the system for effective shaping are specified. Predictions of the flying mirror model for shaping are compared with the 1D PIC simulations, showing good agreement.« less

The reference cube: A new ballistic model to generate staining in firearm barrels.

PubMed

Schyma, Christian; Bauer, Kristina; Brünig, Julia

2017-06-01

After contact shots to the head biological traces can be found inside firearm barrels. So far silicone coated, gelatin filled box models were used to generate such staining according to the triple contrast method (mixture of acrylic paint, barium sulfate and blood sealed in a thin foil bag). This study was conducted to develop a transparent ballistic model allowing contact shots. Gelatin filled polyethylene bottles with and without a silicone coat were tested in comparison to non-covered gelatin blocks. Finally, thin foil bags of 5 cm × 5 cm dimension were glued on a synthetic absorbent kitchen wipe on top of which 1 L 10% gelatin solution was molded to create blocks of 8.5 cm length. A kitchen wipe with a paint pad on its inside formed the front of the cube. Three contact shots each with a 9 mm Luger pistol and a .38 special revolver were performed on all model variations. The staining was documented by endoscopy and swabs gathered from both ends of the barrel were analyzed by quantitative PCR. Reliable staining was achieved using the front covered gelatin block with comparable results to the silicone coated box model used before. For further research using ballistic models to simulate a human head a symmetric form of the gelatin block such as a cube is recommended.

Modification of Bushing Test Rig and Research of Variable Inlet Guide Vane Bushings For Further Development of PM304 Bushings

NASA Technical Reports Server (NTRS)

Yanke, Anne

2004-01-01

PS304 is a high temperature solid lubricant coating comprised of a nickel-chrome binder, chrome oxide hardener, barium-calcium fluoride high temperature lubricant, and silver as the low temperature lubricant. This coating is used to lubricate Oil-Free Foil Air Bearings as they experience friction and wear during start up and shut down. The coating deposition process begins with undercutting the shaft. This area is then sandblasted to provide a rough surface for the coating to adhere to. The coating powder is then sent through the plasma spray gun and a reasonably thick layer is applied to the undercut area of the shaft. The coating is then ground down even with the surface of the shaft and gets a nice polished finish. The foil air bearings use the solid lubricant, as mentioned above, during start up and shut down. During normal operating conditions, generally above 2000RPM, the bearings utilize air as their lubricant. Foil air bearings are comprised of a thin top foil and a corrugated bump foil. They have an interference fit with the shaft before operation. As the air gets "trapped" between the top foil and the shaft, it presses the top foil against the bump foil, in turn compressing the bumps. As the bumps compress, it allows for the air to separate the top foil from the shaft, therefore, utilizing the trapped air as its lubricant.

Nonlinear Dynamics of a Foil Bearing Supported Rotor System: Simulation and Analysis

NASA Technical Reports Server (NTRS)

Li, Feng; Flowers, George T.

1996-01-01

Foil bearings provide noncontacting rotor support through a number of thin metal strips attached around the circumference of a stator and separated from the rotor by a fluid film. The resulting support stiffness is dominated by the characteristics of the foils and is a nonlinear function of the rotor deflection. The present study is concerned with characterizing this nonlinear effect and investigating its influence on rotordynamical behavior. A finite element model is developed for an existing bearing, the force versus deflection relation characterized, and the dynamics of a sample rotor system are studied. Some conclusions are discussed with regard to appropriate ranges of operation for such a system.

Final Report: Sintered CZTS Nanoparticle Solar Cells on Metal Foil; July 26, 2011 - July 25, 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leidholm, C.; Hotz, C.; Breeze, A.

2012-09-01

This is the final report covering 12 months of this subcontract for research on high-efficiency copper zinc tin sulfide (CZTS)-based thin-film solar cells on flexible metal foil. Each of the first three quarters of the subcontract has been detailed in quarterly reports. In this final report highlights of the first three quarters will be provided and details will be given of the final quarter of the subcontract.

Role of Friction on the Thermal Development in Ultrasonically Consolidated Aluminum Foils and Composites

DTIC Science & Technology

2011-01-01

amplitude, . The third input parameter, weld speed, s, is inversely proportional to N, the num- ber of cycles as shown in Eq. (3). In summary, F is...though, an extensive body of work on mechanical testing of ultrasonically consolidated thin foils has been performed at Loughborough University. In...comprehensive textbook on tribology presents a preliminary derivation for plastic contact of ductile metals which suggests ≤ 1/5; this is much lower

Improved properties of barium strontium titanate thin films grown on copper foils by pulsed laser deposition using a self-buffered layer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, S.; Ma, B.; Narayanan, M.

2012-01-01

Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) films were deposited by pulsed laser deposition on copper foils with low-temperature self-buffered layers. The deposition conditions included a low oxygen partial pressure and a temperature of 700 C to crystallize the films without the formation of secondary phases and substrate oxidation. The results from x-ray diffraction and scanning electron microscopy indicated that the microstructure of the BST films strongly depended on the growth temperature. The use of the self-buffered layer improved the dielectric properties of the deposited BST films. The leakage current density of the BST films on the copper foil was 4.4 xmore » 10{sup -9} A cm{sup -2} and 3.3 x 10{sup -6} A cm{sup -2} with and without the self-buffered layer, respectively. The ferroelectric hysteresis loop for the BST thin film with buffer layer was slim, in contrast to the distorted loop observed for the film without the buffer layer. The permittivity (7 0 0) and dielectric loss tangent (0.013) of the BST film on the copper foil with self-buffered layer at room temperature were comparable to those of the film on metal and single-crystal substrates.« less

A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

2002-01-01

Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

Explosion of thin aluminum foils in air

NASA Astrophysics Data System (ADS)

Baksht, R.; Pokryvailo, A.; Yankelevich, Y.; Ziv, I.

2004-12-01

An inductive-based power supply (240μH, 50kA) was used for the investigation of the foil explosion process in the time range of 0.05ms

Large-scale studies of ion acceleration in laser-generated plasma at intensities from 1010 W/cm2 to 1019 W/cm2

NASA Astrophysics Data System (ADS)

Torrisi, L.

2018-02-01

A large-scale study of ion acceleration in laser-generated plasma, extended to intensities from 1010 W/cm2 up to 1019 W/cm2, is presented. Aluminium thick and thin foils were irradiated in high vacuum using different infrared lasers and pulse durations from ns up to fs scale. Plasma was monitored mainly using SiC detectors employed in time-of-flight configuration. Protons and aluminium ions, at different energies and yields, were measured as a function of the laser intensity. The discontinuity region between particle acceleration from both the backward plasma (BPA) in thick targets and the forward plasma in thin foils in the target normal sheath acceleration (TNSA) regimes were investigated.

Additional security features for optically variable foils

NASA Astrophysics Data System (ADS)

Marshall, Allan C.; Russo, Frank

1998-04-01

For thousands of years, man has exploited the attraction and radiance of pure gold to adorn articles of great significance. Today, designers decorate packaging with metallic gold foils to maintain the prestige of luxury items such as perfumes, chocolates, wine and whisky, and to add visible appeal and value to wide range of products. However, today's products do not call for the hand beaten gold leaf of the Ancient Egyptians, instead a rapid production technology exists which makes use of accurately coated thin polymer films and vacuum deposited metallic layers. Stamping Foils Technology is highly versatile since several different layers may be combined into one product, each providing a different function. Not only can a foil bring visual appeal to an article, it can provide physical and chemical resistance properties and also protect an article from human forms of interference, such as counterfeiting, copying or tampering. Stamping foils have proved to be a highly effective vehicle for applying optical devices to items requiring this type of protection. Credit cards, bank notes, personal identification documents and more recently high value packaged items such as software and perfumes are protected by optically variable devices applied using stamping foil technology.

"Light sail" acceleration reexamined.

PubMed

Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

2009-08-21

The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

Digital Systems Validation Handbook. Volume 2

DTIC Science & Technology

1989-02-01

power. 2. A grid of wires, solid sheet, or foil. 3. A wire from circuit to grounding block or case. 4. A wire from circuit to structure. 5. Shield...RETURN. (11) 1. Structure, for power, fault, and "discrete" circuits. 2. A grid of wires, solid sheet, or foil. 3. A wire from circuit load back to...TV (14) Television TWTD (13) Thin Wire Time Domain TX (5) Transmit U.K. (13,141 United Kingdom U.S. (14) United States UART (15) Universal Asynchronous

Thermal Loading of Thin Metal Foils Used as Electron Beam Windows for a KRF Laser

DTIC Science & Technology

2005-06-01

the Inertial Fusion Energy (IFE) requirements for durability, efficiency, and cost. One of the challenging laser components is the pressure foil that...R. Welch, D. V. Rose, and S. Searles, "Electron beam pumped krypton fluoride lasers for fusion energy ," Proc. IEEE, vol. 92, pp. 1043-1056, July...D. Weidenheimer, and D. V. Rose, "Repetitively pulsed, high energy KrF lasers for inertial fusion energy ," Nucl. Fusion, vol. 44, pp. S247-S253

Controlled ion track etching

NASA Astrophysics Data System (ADS)

George, J.; Irkens, M.; Neumann, S.; Scherer, U. W.; Srivastava, A.; Sinha, D.; Fink, D.

2006-03-01

It is a common practice since long to follow the ion track-etching process in thin foils via conductometry, i.e . by measurement of the electrical current which passes through the etched track, once the track breakthrough condition has been achieved. The major disadvantage of this approach, namely the absence of any major detectable signal before breakthrough, can be avoided by examining the track-etching process capacitively. This method allows one to define precisely not only the breakthrough point before it is reached, but also the length of any non-transient track. Combining both capacitive and conductive etching allows one to control the etching process perfectly. Examples and possible applications are given.

Study of meteoroid impact craters on various materials (AO 138-1). Attempt at dust debris collection with stacked detectors (AO 138-2)

NASA Technical Reports Server (NTRS)

Mandeville, Jean Claude

1991-01-01

Part of the Long Duration Exposure Facility (LDEF) tray allocated to French experiments, known as FRECOPA payload, was devoted to the study of dust particles. Two passive experiments were flown: one composed of a set of glass and metallic samples and one composed of multilayer thin foils detectors. In addition to these experiments, a broad variety of materials were exposed to the bombardment of microparticles and provide more data. Thick target experiment comprises selected metallic (Al, Au, Cu, W, Stainless Steel) 250 microns thick and glass surfaces 1.5 mm thick. Crater size distribution from these thick target experiments enable, with the aid of lab calibrations by solid particle accelerators, the evaluation of the incident microparticle flux in the near earth environment. The aim of the multiple foil penetration and collection experiment is primarily to study the feasibility of multilayer thin film detectors acting as energy sorters in order to collect micrometeoroids, if not in their original shape, at least as 'breakup' fragments suitable for chemical analysis. Foil thicknesses range from 0.75 to 5 microns of Al.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bharadwaja, S. S. N., E-mail: s.s.n.bharadwaja@gmail.com; Ko, S. W.; Qu, W.

Excimer laser assisted re-oxidation for reduced, crystallized BaTiO{sub 3} thin films on Ni-foils was investigated. It was found that the BaTiO{sub 3} can be re-oxidized at an oxygen partial pressure of ∼50 mTorr and substrate temperature of 350 °C without forming a NiO{sub x} interface layer between the film and base metal foil. The dielectric permittivity of re-oxidized films was >1000 with loss tangent values <2% at 100 Hz, 30 mV{sub rms} excitation signal. Electron Energy Loss Spectroscopy indicated that BaTiO{sub 3} thin films can be re-oxidized to an oxygen stoichiometry close to ∼3 (e.g., stoichiometric). High resolution cross sectional transmission electronmore » microscopy showed no evidence of NiO{sub x} formation between the BaTiO{sub 3} and the Ni foil upon excimer laser re-oxidation. Spectroscopic ellipsometry studies on laser re-oxidized [001]{sub C} and [111]{sub C} BaTiO{sub 3} single crystals indicate that the re-oxidation of BaTiO{sub 3} single crystals is augmented by photo-excitation of the ozone, as well as laser pulse induced temperature and local stress gradients.« less

Gold leaf counter electrodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Shimada, Kazuhiro; Toyoda, Takeshi

2018-03-01

In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

An ultra-lightweight design for imperceptible plastic electronics.

PubMed

Kaltenbrunner, Martin; Sekitani, Tsuyoshi; Reeder, Jonathan; Yokota, Tomoyuki; Kuribara, Kazunori; Tokuhara, Takeyoshi; Drack, Michael; Schwödiauer, Reinhard; Graz, Ingrid; Bauer-Gogonea, Simona; Bauer, Siegfried; Someya, Takao

2013-07-25

Electronic devices have advanced from their heavy, bulky origins to become smart, mobile appliances. Nevertheless, they remain rigid, which precludes their intimate integration into everyday life. Flexible, textile and stretchable electronics are emerging research areas and may yield mainstream technologies. Rollable and unbreakable backplanes with amorphous silicon field-effect transistors on steel substrates only 3 μm thick have been demonstrated. On polymer substrates, bending radii of 0.1 mm have been achieved in flexible electronic devices. Concurrently, the need for compliant electronics that can not only be flexed but also conform to three-dimensional shapes has emerged. Approaches include the transfer of ultrathin polyimide layers encapsulating silicon CMOS circuits onto pre-stretched elastomers, the use of conductive elastomers integrated with organic field-effect transistors (OFETs) on polyimide islands, and fabrication of OFETs and gold interconnects on elastic substrates to realize pressure, temperature and optical sensors. Here we present a platform that makes electronics both virtually unbreakable and imperceptible. Fabricated directly on ultrathin (1 μm) polymer foils, our electronic circuits are light (3 g m(-2)) and ultraflexible and conform to their ambient, dynamic environment. Organic transistors with an ultra-dense oxide gate dielectric a few nanometres thick formed at room temperature enable sophisticated large-area electronic foils with unprecedented mechanical and environmental stability: they withstand repeated bending to radii of 5 μm and less, can be crumpled like paper, accommodate stretching up to 230% on prestrained elastomers, and can be operated at high temperatures and in aqueous environments. Because manufacturing costs of organic electronics are potentially low, imperceptible electronic foils may be as common in the future as plastic wrap is today. Applications include matrix-addressed tactile sensor foils for health care and monitoring, thin-film heaters, temperature and infrared sensors, displays, and organic solar cells.

Gas insulated transmission line having low inductance intercalated sheath

DOEpatents

Cookson, Alan H.

1978-01-01

A gas insulated transmission line including an outer sheath, an inner conductor disposed within the outer sheath, and an insulating gas between the inner conductor and the outer sheath. The outer sheath comprises an insulating tube having first and second ends, and having interior and exterior surfaces. A first electrically conducting foil is secured to the interior surface of the insulating tube, is spirally wound from one tube end to the second tube end, and has a plurality of overlapping turns. A second electrically conducting foil is secured to the exterior surface of the insulating tube, and is spirally wound in the opposite direction from the first electrically conducting foil. By winding the foils in opposite directions, the inductances within the intercalated sheath will cancel each other out.

Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

NASA Astrophysics Data System (ADS)

Fan, Qiwen; Du, Yinghui; Zhang, Rong; Xu, Guoji

2013-04-01

Thin diamond-like carbon (DLC) stripper foils ˜5 μg/cm2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ˜4 μg/cm2 in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine-saccharose as releasing agent, which were previously covered with evaporated carbon layers ˜1 μg/cm2 in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4for the 197Au- (˜9 MeV, ˜1 μA) and 63Cu- (˜9 MeV, ˜1 μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (ID/IG) measured by the Raman spectroscopy is0.78.

A direct thin-film path towards low-cost large-area III-V photovoltaics

PubMed Central

Kapadia, Rehan; Yu, Zhibin; Wang, Hsin-Hua H.; Zheng, Maxwell; Battaglia, Corsin; Hettick, Mark; Kiriya, Daisuke; Takei, Kuniharu; Lobaccaro, Peter; Beeman, Jeffrey W.; Ager, Joel W.; Maboudian, Roya; Chrzan, Daryl C.; Javey, Ali

2013-01-01

III-V photovoltaics (PVs) have demonstrated the highest power conversion efficiencies for both single- and multi-junction cells. However, expensive epitaxial growth substrates, low precursor utilization rates, long growth times, and large equipment investments restrict applications to concentrated and space photovoltaics (PVs). Here, we demonstrate the first vapor-liquid-solid (VLS) growth of high-quality III-V thin-films on metal foils as a promising platform for large-area terrestrial PVs overcoming the above obstacles. We demonstrate 1–3 μm thick InP thin-films on Mo foils with ultra-large grain size up to 100 μm, which is ~100 times larger than those obtained by conventional growth processes. The films exhibit electron mobilities as high as 500 cm2/V-s and minority carrier lifetimes as long as 2.5 ns. Furthermore, under 1-sun equivalent illumination, photoluminescence efficiency measurements indicate that an open circuit voltage of up to 930 mV can be achieved, only 40 mV lower than measured on a single crystal reference wafer. PMID:23881474

Weldment for austenitic stainless steel and method

DOEpatents

Bagnall, Christopher; McBride, Marvin A.

1985-01-01

For making defect-free welds for joining two austenitic stainless steel mers, using gas tungsten-arc welding, a thin foil-like iron member is placed between the two steel members to be joined, prior to making the weld, with the foil-like iron member having a higher melting point than the stainless steel members. When the weld is formed, there results a weld nugget comprising melted and then solidified portions of the joined members with small portions of the foil-like iron member projecting into the solidified weld nugget. The portions of the weld nugget proximate the small portions of the foil-like iron member which project into the weld nugget are relatively rich in iron. This causes these iron-rich nugget portions to display substantial delta ferrite during solidification of the weld nugget which eliminates weld defects which could otherwise occur. This is especially useful for joining austenitic steel members which, when just below the solidus temperature, include at most only a very minor proportion of delta ferrite.

[Microfabricated X-ray Optics Technology Development for the Constellation X-Mission

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2005-01-01

MIT has previously developed advanced methods for the application of silicon microstructures (so-called microcombs) in the precision assembly of foil x-ray optics in support of the Constellation-X Spectroscopy X-ray Telescope (SXT) technology development at the NASA Goddard Space Flight Center (GSFC). During the first year of the above Cooperative Agreement, MIT has developed a new, mature, potentially high- yield process for the manufacturing of microcombs that can be applied to a range of substrates independent of thickness. MIT also developed techniques to extract microcomb accuracy from an assembly truss metrology test stand and to extend the dynamic range of its Shack-Hartmann foil metrology tool. The placement repeatability of foil optics with microcombs in the assembly truss has been improved by a factor of two to approximately 0.15 micron. This was achieved by electric contact determination in favor of determining contact through force measurements. Development work on a stress-free thin foil holder was also supported by this agreement and successfully continued under a different grant.

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R F; Bailey, J E; Cuneo, M E

We report the development of techniques to diagnose plasmas produced by X-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW X-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated 3-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments in which 1 cm, 180 eV tungsten pinches photoionized foils composed of 200{angstrom} Fe and 300{angstrom} NaF co-mixed and sandwiched between 1000{angstrom} layers of Lexan (CHO), and discuss the application of this work to benchmarking astrophysical models.« less

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R. F.; Bailey, J. E.; Cuneo, M. E.

We report the development of techniques to diagnose plasmas produced by x-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW x-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated three-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments using 1-cm, 180-eV tungsten pinches to photoionize foils made of 200 Aa Fe and 300 Aa NaF co-mixed and sandwiched between 1000 Aa layers of Lexan (C16H14O3), and discuss the application of this work to benchmarking astrophysical models.« less

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming.

PubMed

Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

2016-07-13

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Single-jet gas cooling of in-beam foils or specimens: Prediction of the convective heat-transfer coefficient

NASA Astrophysics Data System (ADS)

Steyn, Gideon; Vermeulen, Christiaan

2018-05-01

An experiment was designed to study the effect of the jet direction on convective heat-transfer coefficients in single-jet gas cooling of a small heated surface, such as typically induced by an accelerated ion beam on a thin foil or specimen. The hot spot was provided using a small electrically heated plate. Heat-transfer calculations were performed using simple empirical methods based on dimensional analysis as well as by means of an advanced computational fluid dynamics (CFD) code. The results provide an explanation for the observed turbulent cooling of a double-foil, Havar beam window with fast-flowing helium, located on a target station for radionuclide production with a 66 MeV proton beam at a cyclotron facility.

Investigation of the aluminium-aluminium oxide reversible transformation as observed by hot stage electron microscopy.

NASA Technical Reports Server (NTRS)

Grove, C. A.; Judd, G.; Ansell, G. S.

1972-01-01

Thin foils of high purity aluminium and an Al-Al2O3 SAP type of alloy were oxidised in a specially designed hot stage specimen chamber in an electron microscope. Below 450 C, amorphous aluminium oxide formed on the foil surface and was first detectable at foil edges, holes, and pits. Islands of aluminium then nucleated in this amorphous oxide. The aluminium islands displayed either a lateral growth with eventual coalescence with other islands, or a reoxidation process which caused the islands to disappear. The aluminium island formation was determined to be related to the presence of the electron beam. A mechanism based upon electron charging due to the electron beam was proposed to explain the nucleation, growth, coalescence, disappearance, and geometry of the aluminium islands.

Novel target design for enhanced laser driven proton acceleration

NASA Astrophysics Data System (ADS)

Dalui, Malay; Kundu, M.; Tata, Sheroy; Lad, Amit D.; Jha, J.; Ray, Krishanu; Krishnamurthy, M.

2017-09-01

We demonstrate a simple method of preparing structured target for enhanced laser-driven proton acceleration under target-normal-sheath-acceleration scheme. A few layers of genetically modified, clinically grown micron sized E. Coli bacteria cell coated on a thin metal foil has resulted in an increase in the maximum proton energy by about 1.5 times and the total proton yield is enhanced by approximately 25 times compared to an unstructured reference foil at a laser intensity of 1019 W/cm2. Particle-in-cell simulations on the system shows that the structures on the target-foil facilitates anharmonic resonance, contributing to enhanced hot electron production which leads to stronger accelerating field. The effect is observed to grow as the number of structures is increased in the focal area of the laser pulse.

GRAPHITE BONDING METHOD

DOEpatents

King, L.D.P.

1964-02-25

A process for bonding or joining graphite members together in which a thin platinum foil is placed between the members, heated in an inert atmosphere to a temperature of 1800 deg C, and then cooled to room temperature is described. (AEC)

Definition of the Spatial Resolution of X-Ray Microanalysis in Thin Foils

NASA Technical Reports Server (NTRS)

Williams, D. B.; Michael, J. R.; Goldstein, J. I.; Romig, A. D., Jr.

1992-01-01

The spatial resolution of X-ray microanalysis in thin foils is defined in terms of the incident electron beam diameter and the average beam broadening. The beam diameter is defined as the full width tenth maximum of a Gaussian intensity distribution. The spatial resolution is calculated by a convolution of the beam diameter and the average beam broadening. This definition of the spatial resolution can be related simply to experimental measurements of composition profiles across interphase interfaces. Monte Carlo calculations using a high-speed parallel supercomputer show good agreement with this definition of the spatial resolution and calculations based on this definition. The agreement is good over a range of specimen thicknesses and atomic number, but is poor when excessive beam tailing distorts the assumed Gaussian electron intensity distributions. Beam tailing occurs in low-Z materials because of fast secondary electrons and in high-Z materials because of plural scattering.

Photo-Induced Room-Temperature Gas Sensing with a-IGZO Based Thin-Film Transistors Fabricated on Flexible Plastic Foil.

PubMed

Knobelspies, Stefan; Bierer, Benedikt; Daus, Alwin; Takabayashi, Alain; Salvatore, Giovanni Antonio; Cantarella, Giuseppe; Ortiz Perez, Alvaro; Wöllenstein, Jürgen; Palzer, Stefan; Tröster, Gerhard

2018-01-26

We present a gas sensitive thin-film transistor (TFT) based on an amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) semiconductor as the sensing layer, which is fabricated on a free-standing flexible polyimide foil. The photo-induced sensor response to NO₂ gas at room temperature and the cross-sensitivity to humidity are investigated. We combine the advantages of a transistor based sensor with flexible electronics technology to demonstrate the first flexible a-IGZO based gas sensitive TFT. Since flexible plastic substrates prohibit the use of high operating temperatures, the charge generation is promoted with the help of UV-light absorption, which ultimately triggers the reversible chemical reaction with the trace gas. Furthermore, the device fabrication process flow can be directly implemented in standard TFT technology, allowing for the parallel integration of the sensor and analog or logical circuits.

Thin Shell, Segmented X-Ray Mirrors

NASA Technical Reports Server (NTRS)

Petre, Robert

2010-01-01

Thin foil mirrors were introduced as a means of achieving high throughput in an X-ray astronomical imaging system in applications for which high angular resolution were not necessary. Since their introduction, their high filling factor, modest mass, relative ease of construction, and modest cost have led to their use in numerous X-ray observatories, including the Broad Band X-ray Telescope, ASCA, and Suzaku. The introduction of key innovations, including epoxy replicated surfaces, multilayer coatings, and glass mirror substrates, has led to performance improvements, and in their becoming widely used for X-ray astronomical imaging at energies above 10 keV. The use of glass substrates has also led to substantial improvement in angular resolution, and thus their incorporation into the NASA concept for the International X-ray Observatory with a planned 3 in diameter aperture. This paper traces the development of foil mirrors from their inception in the 1970's through their current and anticipated future applications.

Strong electromagnetic pulses generated in laser-matter interactions with 10TW-class fs laser

NASA Astrophysics Data System (ADS)

Rączka, Piotr; Rosiński, Marcin; Zaraś-Szydłowska, Agnieszka; Wołowski, Jerzy; Badziak, Jan

2018-01-01

The results of an experiment on the generation of electromagnetic pulses (EMP) in the interaction of 10TW fs pulses with thick (mm scale) and thin foil (μm scale) targets are described. Such pulses, with frequencies in the GHz range, may pose a threat to safe and reliable operation of high-power, high-intensity laser facilities. The main point of the experiment is to investigate the fine temporal structure of such pulses using an oscilloscope capable of measurements at very high sampling rate. It is found that the amazing reproducibility of such pulses is confirmed at this high sampling rate. Furthermore, the differences between the EMP signals generated from thick and thin foil targets are clearly seen, which indicates that besides electric polarization of the target and the target neutralization current there may be other factors essential for the EMP emission.

Photo-Induced Room-Temperature Gas Sensing with a-IGZO Based Thin-Film Transistors Fabricated on Flexible Plastic Foil

PubMed Central

Bierer, Benedikt; Takabayashi, Alain; Ortiz Perez, Alvaro; Wöllenstein, Jürgen

2018-01-01

We present a gas sensitive thin-film transistor (TFT) based on an amorphous Indium–Gallium–Zinc–Oxide (a-IGZO) semiconductor as the sensing layer, which is fabricated on a free-standing flexible polyimide foil. The photo-induced sensor response to NO2 gas at room temperature and the cross-sensitivity to humidity are investigated. We combine the advantages of a transistor based sensor with flexible electronics technology to demonstrate the first flexible a-IGZO based gas sensitive TFT. Since flexible plastic substrates prohibit the use of high operating temperatures, the charge generation is promoted with the help of UV-light absorption, which ultimately triggers the reversible chemical reaction with the trace gas. Furthermore, the device fabrication process flow can be directly implemented in standard TFT technology, allowing for the parallel integration of the sensor and analog or logical circuits. PMID:29373524

Characterization of Graphene Stripper Foils in 11-MeV Cyclotrons

NASA Astrophysics Data System (ADS)

Korenev, Sergey; Dishman, Rick; Yebra, Alberto; Meshcheryakov, Nikolay; Smirnov, Ilya; Pavlovsky, Igor; Fink, Richard

An experimental study of the use of graphene as an extractor (stripper) foil in the 11-MeV Siemens Eclipse Cyclotron is discussed in this paper. The main advantage of graphene is its high thermal conductivity compared to that of amorphous carbon films. Graphene also has significant mechanical strength. The lifetime of the graphene foils under proton bombardment exceeded 16,000 μAh. Graphene-based stripper foils demonstrated a significant increase in the transmission factor (defined as the ratio of the beam current on the target to the beam current on the stripper foil), which was approximately 90%. Fabrication of the graphene-based foils is discussed. The pros and cons of using the graphene material as a stripper foil in cyclotrons are analyzed.

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming

PubMed Central

Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

2016-01-01

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination. PMID:28773692

Application study on aircraft structures of CFRP laminates with embedded SMA foils

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Takeda, Nobuo

2002-07-01

This paper reports some research results for the application study of the smart materials an structural using Shape Memory Alloy (SMA) foils. First, the authors acquired the recovery strain of CFRP laminates generated by the recovery stress of the pre-strained SMA foils. Then, the quasi-static load-unload tests were conducted using several kinds of quasi-isotropic CFRP laminates with embedded SMA foils. Micro-mechanics of damage behavior due to the effects of the recovery strain and the first transverse crack strain were discussed. The improvement of maximum 40 percent for the onset strain of the transverse cracks and maximum 60 percent for the onset strain of delamination were achieved for CFRP laminates with embedded pre-strained SMA foils compared with standard CFRP laminates. Furthermore, the authors conducted the structural element test for application to actual structures. Testing technique and the manufacturing technique of the structural element specimen were established.

Microstructures and properties of rapidly solidified alloys

NASA Technical Reports Server (NTRS)

Shechtman, D.; Horowitz, E.

1984-01-01

The microstructure and properties of rapidly solidified aluminum alloys were researched. The effects of powder and flake chemistry and morphology and alternative consolidation processing parameters are being conducted. Samples of the powders being utilized were obtained for comprehensive metallurgical characterization. Seven aluminum alloys in the form of thin foils were studied by a variety of techniques including optical metallography, scanning electron microscope, and transmission electron microscope. Details of the microstructural characteristics are presented along with a discussion of the solidification process. A better understanding of the microstructure of the rapidly solidified aluminum alloys prepared by a variety of techniques such as roller quenching, the vacuum atomized procedure, ultrasonically atomized in inert atmospheres, and atomized in flue gas was provided.

A new measurement of electron transverse polarization in polarized nuclear β-decay

NASA Astrophysics Data System (ADS)

Kawamura, H.; Akiyama, T.; Hata, M.; Hirayama, Y.; Ikeda, M.; Ikeda, Y.; Ishii, T.; Kameda, D.; Mitsuoka, S.; Miyatake, H.; Nagae, D.; Nakaya, Y.; Ninomiya, K.; Nitta, M.; Ogawa, N.; Onishi, J.; Seitaibashi, E.; Tanaka, S.; Tanuma, R.; Totsuka, Y.; Toyoda, T.; Watanabe, Y. X.; Murata, J.

2017-03-01

The Mott polarimetry for T-violation (MTV) experiment tests time-reversal symmetry in polarized nuclear β-decay by measuring an electron’s transverse polarization as a form of angular asymmetry in Mott scattering using a thin metal foil. A Mott scattering analyzer system developed using a tracking detector to measure scattering angles offers better event selectivity than conventional counter experiments. In this paper, we describe a pilot experiment conducted at KEK-TRIAC using a prototype system with a polarized 8Li beam. The experiment confirmed the sound performance of our Mott analyzer system to measure T-violating triple correlation (R correlation), and therefore recommends its use in higher-precision experiments at the TRIUMF-ISAC.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer.more » A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.« less

Near monochromatic 20 Me V proton acceleration using fs laser irradiating Au foils in target normal sheath acceleration regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torrisi, L., E-mail: Lorenzo.Torrisi@unime.it; Ceccio, G.; Cannavò, A.

2016-04-15

A 200 mJ laser pulse energy, 39 fs-pulse duration, 10 μm focal spot, p-polarized radiation has been employed to irradiate thin Au foils to produce proton acceleration in the forward direction. Gold foils were employed to produce high density relativistic electrons emission in the forward direction to generate a high electric field driving the ion acceleration. Measurements were performed by changing the focal position in respect of the target surface. Proton acceleration was monitored using fast SiC detectors in time-of-flight configuration. A high proton energy, up to about 20 Me V, with a narrow energy distribution, was obtained in particular conditions dependingmore » on the laser parameters, the irradiation conditions, and a target optimization.« less

Technical Note: An investigation of polarity effects for wide-angle free-air chambers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, H., E-mail: Hong.Shen@nrc-cnrc.gc.ca; Ross,

2016-07-15

Purpose: Wide-angle free-air chambers (WAFACs) are used as primary standard measurement devices for establishing the air-kerma strength of low-energy, low-dose rate brachytherapy seeds. The National Research Council of Canada (NRC) is commissioning a primary standard wide-angle free-air chamber (NRC WAFAC) to serve the calibration needs of Canadian clients. The University of Wisconsin has developed a similar variable-aperture free-air chamber (UW VAFAC) to be used as a research tool. As part of the NRC commissioning, measurements were carried out for both polarities of the applied bias voltage and the resulting effects were observed to be very large. Similar effects were identifiedmore » with the UW VAFAC. The authors describe the measurements carried out to determine the underlying causes of the polarity effect and the approach used to eliminate it. Methods: The NRC WAFAC is based on the WAFAC design developed at the National Institute of Standards and Technology in the USA. Charge measurements for {sup 125}I and {sup 241}Am sources were carried out for both negative and positive polarities on the NRC WAFAC and UW VAFAC. Two aperture sizes were also investigated with the UW VAFAC. In addition, measurements on the NRC WAFAC were carried out with a small bias between the collecting electrode and the shield foil at the downstream end of the chamber. To mitigate all of the polarity effects, the downstream surface of the collecting electrode was covered with a thin layer of graphite on both the NRC and UW chambers. Results: Both chamber designs showed a difference of more than 30 % between the charge collected with positive and negative bias voltages for the smallest electrode separation. It was shown for the NRC WAFAC that charge could be collected in the small gap downstream of the collecting volume by applying a voltage between the shield foil and the collecting electrode, even though an insulating foil (Mylar or polyimide film) separated the conducting surface from the small gap region. The unwanted additional current was shown to be proportional to the size of the aperture for the UW VAFAC. The extra ionization produced in the small gap region was eliminated for both chambers by covering the insulating side of the collecting electrode with a grounded conducting layer. Conclusions: The small gap region downstream of the collecting electrode in the NRC WAFAC and UW VAFAC can serve as an unwanted source of ion current. It is concluded that a residual electric field in the small gap region may lead to ion transport and to charge being trapped on the surface of the foil. The foil then acts as a capacitor with an equal charge, but of opposite sign, being attracted to the conducting surface. Covering the back of the collecting electrode surface with a grounded conducting layer eliminated the polarity effect.« less

Insulating effectiveness of self-spacing dimpled foil

NASA Technical Reports Server (NTRS)

Bond, J. A.

1972-01-01

Experimental data are graphed for determining conductive heat losses of multilayer insulation as function of number of foil layers. Foil was 0.0051 cm thick Nb, 1% Zr refractory alloy, dimpled to 0.0254 cm with approximately 28 dimples/sq cm. Heat losses were determined at 0.1 microtorr between 700 and 1089 K.

In situ hydride formation in titanium during focused ion milling.

PubMed

Ding, Rengen; Jones, Ian P

2011-01-01

It is well known that titanium and its alloys are sensitive to electrolytes and thus hydrides are commonly observed in electropolished foils. In this study, focused ion beam (FIB) milling was used to prepare thin foils of titanium and its alloys for transmission electron microscopy. The results show the following: (i) titanium hydrides were observed in pure titanium, (ii) the preparation of a bulk sample in water or acid solution resulted in the formation of more hydrides and (iii) FIB milling aids the precipitation of hydrides, but there were never any hydrides in Ti64 and Ti5553.

Innovative space x-ray telescopes

NASA Astrophysics Data System (ADS)

Hudec, R.; Inneman, A.; Pina, L.; Sveda, L.; Ticha, H.; Brozek, V.

2017-11-01

We report on the progress in innovative X-ray mirror development with focus on requirements of future X-ray astronomy space projects. Various future projects in X-ray astronomy and astrophysics will require large lightweight but highly accurate segments with multiple thin shells or foils. The large Wolter 1 grazing incidence multiple mirror arrays, the Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (shaped, bent or flat foils) with high X-ray reflectivity and excellent mechanical stability.

Electronic and Physical Characterization of Hydrothermally Grown Single Crystal ThO2

DTIC Science & Technology

2013-12-26

35 BNL Brookhaven National Laboratories . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 VBM valence band maximum...Newton’s method. As an example, EXAFS data from Brookhaven National Laboratories ( BNL ) is analyzed. The data is from a thin metal Cu foil. A reasonable

Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum.

PubMed

Morgan, Dane V; Macy, Don; Stevens, Gerald

2008-11-01

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35 ns pulse. The characteristic K(alpha) lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K(beta) line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3 x 6 mm(2) spot and 1 degrees full width half maximum angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5 degrees . A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device camera through a coherent fiber-optic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1 mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic aluminum lattice with no phase transformation.

Film Delivery Module For Fiber Placement Fabrication of Hybridized Composite Structures

NASA Technical Reports Server (NTRS)

Hulcher, Anthony Bruce; Young, Greg

2005-01-01

A new fabrication technology has been developed at the NASA Marshall Space Flight Center that will allow for the fabrication of hybridized composite structures using fiber placement processing. This technology was originally developed in response to a need to address the issue of hydrogen permeation and microcracking in cryogenic propellant tanks. Numerous thin polymeric and metallized films were investigated under low temperatures conditions for use as barrier films in a composite tank. Manufacturing studies conducted at that time did not address the processing issues related to fabrication of a hybridized tank wall. A film processing head was developed that will allow for the processing of thin polymeric and metallized films, metallic foils, and adhesives using fiber placement processing machinery. The film head is designed to enable the simultaneous processing of film materials and composite tape/tow during the composite part layup process and is also capable of processing the film during an independent operation. Several initial demonstrations were conducted to assess the performance of the film module device. Such assessments included film strip lay-up accuracy, capability to fabricate panels having internal film liners, and fabrication of laminates with embedded film layers.

Impact of selected parameters on the development of boiling and flow resistance in the minichannel

NASA Astrophysics Data System (ADS)

Piasecka, Magdalena; Ziętala, Kinga

2015-05-01

The paper presents results of flow boiling in a rectangular minichannel 1 mm deep, 40 mm wide and 360 mm long. The heating element for FC-72 flowing in the minichannel was the thin alloy foil designated as Haynes-230. There was a microstructure on the side of the foil which comes into contact with fluid in the channel. Two types of microstructured heating surfaces: one with micro-recesses distributed evenly and another with mini-recesses distributed unevenly were used. The paper compares the impact of the microstructured heating surface and minichannel positions on the development of boiling and two phase flow pressure drop. The local heat transfer coefficients and flow resistance obtained in experiment using three positions of the minichannel, e.g.: 0°, 90° and 180° were analyzed. The study of the selected thermal and flow parameters (mass flux density and inlet pressure), geometric parameters and type of cooling liquid on the boiling heat transfer was also conducted. The most important factor turned out to be channel orientation. Application of the enhanced heating surface caused the increase of the heat transfer coefficient from several to several tens per cent, in relation to the plain surface.

Continuous-wave laser-induced glass fiber generation

NASA Astrophysics Data System (ADS)

Nishioka, Nobuyasu; Hidai, Hirofumi; Matsusaka, Souta; Chiba, Akira; Morita, Noboru

2017-09-01

Pulsed-laser-induced glass fiber generation has been reported. We demonstrate a novel glass fiber generation technique by continuous-wave laser illumination and reveal the generation mechanism. In this technique, borosilicate glass, metal foil, and a heat insulator are stacked and clamped by a jig as the sample. Glass fibers are ejected from the side surface of the borosilicate glass by laser illumination of the sample from the borosilicate glass side. SEM observation shows that nanoparticles are attached on the glass fibers. High-speed imaging reveals that small bubbles are formed at the side surface of the borosilicate glass and the bursting of the bubble ejects the fibers. The temperature at the fiber ejection point is estimated to be 1220 K. The mechanism of the fiber ejection includes the following steps: the metal thin foil heated by the laser increases the temperature of the surrounding glass by heat conduction. Since the absorption coefficient of the glass is increased by increasing the temperature, the glass starts to absorb the laser irradiation. The heated glass softens and bubbles form. When the bubble bursts, molten glass and gas inside the bubble scatter into the air to generate the glass fibers.

Long pulse Soft X-ray Emission from Laser Generated Irradiated Gold Foils

NASA Astrophysics Data System (ADS)

Davis, Joshua; Frank, Yechiel; Raicher, Erez; Fraenkel, Moshe; Keiter, Paul; Klein, Sallee; Drake, R. P.; Shvarts, Dov

2016-10-01

Long pulse soft x-ray sources (SXS) allow for flexibility in high-energy-density experimental designs by providing a means of driving matter to the high temperatures needed, for example to study radiation waves in different materials. SXSs can be made by using lasers to heat a high-Z thin foil, which then acts as a quasi-blackbody emitter. Previous studies of the x-ray emission characteristics of gold foils have focused on laser pulses of 1ns or less. We performed experiments using a 6.0ns laser pulse with energy of 2kJ on the Omega-60 system to generate and characterize multi-ns laser heated Au foils of thicknesses between 0.5-2.0 μm. We measured the 2D spatial profile of the emission with a soft x-ray camera and the time history of the emission with the Dante photodiode array . Effective temperatures for the emission were then calculated using the Dante measurements. Discussion of experimental results and a comparison with 1-D Rad-Hydro NLTE simulations will be presented.

Apparatus and method for treating a cathode material provided on a thin-film substrate

DOEpatents

Hanson, Eric J.; Kooyer, Richard L.

2001-01-01

An apparatus and method for treating a cathode material provided on a surface of a continuous thin-film substrate and a treated thin-film cathode having increased smoothness are disclosed. A web of untreated cathode material is moved between a feed mechanism and a take-up mechanism, and passed through a treatment station. The web of cathode material typically includes areas having surface defects, such as prominences extending from the surface of the cathode material. The surface of the cathode material is treated with an abrasive material to reduce the height of the prominences so as to increase an 85 degree gloss value of the cathode material surface by at least approximately 10. The web of cathode material may be subjected to a subsequent abrasive treatment at the same or other treatment station. Burnishing or lapping film is employed at a treatment station to process the cathode material. An abrasive roller may alternatively be used to process the web of cathode material. The apparatus and method of the present invention may also be employed to treat the surface of a lithium anode foil so as to cleanse and reduce the roughness of the anode foil surface.

Apparatus and method for treating a cathode material provided on a thin-film substrate

DOEpatents

Hanson, Eric J.; Kooyer, Richard L.

2003-01-01

An apparatus and method for treating a cathode material provided on a surface of a continuous thin-film substrate and a treated thin-film cathode having increased smoothness are disclosed. A web of untreated cathode material is moved between a feed mechanism and a take-up mechanism, and passed through a treatment station. The web of cathode material typically includes areas having surface defects, such as prominences extending from the surface of the cathode material. The surface of the cathode material is treated with an abrasive material to reduce the height of the prominences so as to increase an 85 degree gloss value of the cathode material surface by at least approximately 10. The web of cathode material may be subjected to a subsequent abrasive treatment at the same or other treatment station. Burnishing or lapping film is employed at a treatment station to process the cathode material. An abrasive roller may alternatively be used to process the web of cathode material. The apparatus and method of the present invention may also be employed to treat the surface of a lithium anode foil so as to cleanse and reduce the roughness of the anode foil surface.

Development of damage suppression system using embedded SMA foil in CFRP laminates

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Kobayashi, Masakazu; Okabe, Tomonaga; Takeda, Nobuo

2001-07-01

Some recent studies have suggested possible applications of Shape Memory Alloy (SMA) for a smart health monitoring and suppression of damage growth. The authors have been conducting research and development studies on applications of embedded SMA foil actuators in CFRP laminates as the basic research for next generation aircrafts. First the effective surface treatment for improvement of bonding properties between SMA and CFRP was studied. It was certified that the anodic oxide treatment by 10% NaOH solution was the most effective treatment from the results of peel resistance test and shear strength test. Then, CFRP laminates with embedded SMA foils were successfully fabricated using this effective surface treatment. The damage behavior of quasi-isotropic CFRP laminates with embedded SMA foils was characterized in both quasi-static load-unload and fatigue tests. The relationship between crack density and applied strain was obtained. The recovery stress generated by embedded SMA foils could increase the onset strain of transverse cracking by 0.2%. The onset strain of delmination in CFRP laminates was also increased accordingly. The shear-lag analysis was also conducted to predict the damage evolution in CFRP laminates with embedded SMA foils. The adhesive layers on both sides of SMA foils were treated as shear elements. The theoretical analysis successfully predicted the experimental results.

Investigating the foil-generated deuteron beam interaction with a DT target in degenerate and classical plasma

NASA Astrophysics Data System (ADS)

Mehrangiz, M.; Ghasemizad, A.

2017-06-01

Deuteron fast ignition of a conically guided pre-compressed DT fuel is investigated. For this purpose, the acceleration of the deuterated thin foil by the intense laser beam is evaluated. The acceleration values and the number of foil-generated deuterons are calculated in terms of the laser pulse duration. Using the created deuterons as the fast ignitors, we investigate the fast ignition scheme by comparing fully degenerate, partial degenerate and classical types of DT plasma. The total energy gain of deuterons "beam fusion" is calculated to show the efficiency of beam reactions in increasing fusion rate. Besides, the stopping time and stopping range of incident deuterons are evaluated. Our numerical results indicate that degeneracy increases the beam-target collisions. Thus, it prepares the ignition situation sooner than the classical plasma. Moreover, the number of generated deuterons and their acceleration depend on the foil thickness and laser parameters. We show that when a 4ps laser with intensity of 10^{19} W/cm^2 focused onto a 20μm foil, 35× 10^{15} deuterons are generated. Moreover, under our analysis, in order to have a practicable fast ignition, 18% of the laser energy is necessary to convert into a deuteron driver.

Shock wave driven microparticles for pharmaceutical applications

NASA Astrophysics Data System (ADS)

Menezes, V.; Takayama, K.; Gojani, A.; Hosseini, S. H. R.

2008-10-01

Ablation created by a Q-switched Nd:Yttrium Aluminum Garnet (Nd:YAG) laser beam focusing on a thin aluminum foil surface spontaneously generates a shock wave that propagates through the foil and deforms it at a high speed. This high-speed foil deformation can project dry micro- particles deposited on the anterior surface of the foil at high speeds such that the particles have sufficient momentum to penetrate soft targets. We used this method of particle acceleration to develop a drug delivery device to deliver DNA/drug coated microparticles into soft human-body targets for pharmaceutical applications. The device physics has been studied by observing the process of particle acceleration using a high-speed video camera in a shadowgraph system. Though the initial rate of foil deformation is over 5 km/s, the observed particle velocities are in the range of 900-400 m/s over a distance of 1.5-10 mm from the launch pad. The device has been tested by delivering microparticles into liver tissues of experimental rats and artificial soft human-body targets, modeled using gelatin. The penetration depths observed in the experimental targets are quite encouraging to develop a future clinical therapeutic device for treatments such as gene therapy, treatment of cancer and tumor cells, epidermal and mucosal immunizations etc.

Dual-Chamber/Dual-Anode Proportional Counter Incorporating an Intervening Thin-Foil Solid Neutron Converter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boatner, Lynn A; Neal, John S; Blackston, Matthew A

2012-01-01

A dual-chamber/dual-anode gas proportional counter utilizing thin solid 6LiF or 10B neutron converters coated on a 2-micon-thick Mylar film that is positioned between the two counter chambers and anodes has been designed, fabricated, and tested using a variety of fill gases including naturally abundant helium. In this device, neutron conversion products emitted from both sides of the coated converter foil are detected rather than having half of the products absorbed in the wall of a conventional tube type counter where the solid neutron converter is deposited on the tube wall. Geant4-based radiation transport calculations were used to determine the optimummore » neutron converter coating thickness for both isotopes. Solution methods for applying these optimized-thickness coatings on a Mylar film were developed that were carried out at room temperature without any specialized equipment and that can be adapted to standard coating methods such as silk screen or ink jet printing. The performance characteristics of the dual-chamber/dual-anode neutron detector were determined for both types of isotopically enriched converters. The experimental performance of the 6LiF converter-based detector was described well by modeling results from Geant4. Additional modeling studies of multiple-foil/multiple-chamber/anode configurations addressed the basic issue of the relatively longer absorption range of neutrons versus the shorter range of the conversion products for 6LiF and 10B. Combined with the experimental results, these simulations indicate that a high-performance neutron detector can be realized in a single device through the application of these multiple-foil/solid converter, multiple-chamber detector concepts.« less

Hot slumping glass technology for the grazing incidence optics of future missions with particular reference to IXO

NASA Astrophysics Data System (ADS)

Ghigo, M.; Basso, S.; Bavdaz, M.; Conconi, P.; Citterio, O.; Civitani, M.; Friedrich, P.; Gallieni, D.; Guldimann, B.; Martelli, F.; Negri, R.; Pagano, G.; Pareschi, G.; Parodi, G.; Proserpio, L.; Salmaso, B.; Scaglione, F.; Spiga, D.; Tagliaferri, G.; Terzi, L.; Tintori, M.; Vongehr, M.; Wille, E.; Winter, A.; Zambra, A.

2010-07-01

The mirrors of the International X-ray Observatory (IXO) consist of a large number of high quality segments delivering a spatial resolution better than 5 arcsec. A study concerning the slumping of thin glass foils for the IXO mirrors is under development in Europe, funded by ESA and led by the Brera Observatory. We are investigating two approaches, the "Direct" and "Indirect" slumping technologies, being respectively based on the use of convex and concave moulds. In the first case during the thermal cycle the optical surface of the glass is in direct contact with the mould surface, while in the second case it is the rear side of the foil which touches the master. Both approaches present pros and cons and aim of this study is also to make an assessment of both processes and to perform a trade-off between the two. The thin plates are made of D263glass produced by Schott. Each plate is 0.4 mm thick, with a reflecting area of 200 mm x 200 mm; the mould are made of Fused Silica. After the thermal cycle the slumped MPs are characterized to define their optical quality and microroughness. The adopted integration process foresees the bonding of the slumped foils to a rigid backplane by means of reinforcing ribs. During the bonding process the plates are constrained to stay in close contact to the surface of the master (i.e. the same mould used for the hot slumping process) by the application of a vacuum pump suction. In this way spring-back deformations and low frequency errors still present on the foil profile after slumping can be corrected. In this paper we present the preliminary results concerning achieved during the first part of the project.

Pendulum Testing of an FRP Composite Guardrail: FOIL Test Numbers 96POl9 Through 96PO23, 97POO1, and 97POO2

DOT National Transportation Integrated Search

1998-03-01

This report contains the test setup and results from seven pendulum crash : tests conducted at the Federal Outdoor Impact Laboratory (FOIL) located at the Turner-Fairbank Highway Research Center (TFHRC) in McLean, Virginia. The tests were conducted o...

Characterization of faulted dislocation loops and cavities in ion irradiated alloy 800H

NASA Astrophysics Data System (ADS)

Ulmer, Christopher J.; Motta, Arthur T.

2018-01-01

Alloy 800H is a high nickel austenitic stainless steel with good high temperature mechanical properties which is considered for use in current and advanced nuclear reactor designs. The irradiation response of 800H was examined by characterizing samples that had been bulk ion irradiated at the Michigan Ion Beam Laboratory with 5 MeV Fe2+ ions to 1, 10, and 20 dpa at 440 °C. Transmission electron microscopy was used to measure the size and density of both {111} faulted dislocation loops and cavities as functions of depth from the irradiated surface. The faulted loop density increased with dose from 1 dpa up to 10 dpa where it saturated and remained approximately the same until 20 dpa. The faulted loop average diameter decreased between 1 dpa and 10 dpa and again remained approximately constant from 10 dpa to 20 dpa. Cavities were observed after irradiation doses of 10 and 20 dpa, but not after 1 dpa. The average diameter of cavities increased with dose from 10 to 20 dpa, with a corresponding small decrease in density. Cavity denuded zones were observed near the irradiated surface and near the ion implantation peak. To further understand the microstructural evolution of this alloy, FIB lift-out samples from material irradiated in bulk to 1 and 10 dpa were re-irradiated in-situ in their thin-foil geometry with 1 MeV Kr2+ ions at 440 °C at the Intermediate Voltage Electron Microscope. It was observed that the cavities formed during bulk irradiation shrank under thin-foil irradiation in-situ while dislocation loops were observed to grow and incorporate into the dislocation network. The thin-foil geometry used for in-situ irradiation is believed to cause the cavities to shrink.

QED effects induced harmonics generation in extreme intense laser foil interaction

NASA Astrophysics Data System (ADS)

Yu, J. Y.; Yuan, T.; Liu, W. Y.; Chen, M.; Luo, W.; Weng, S. M.; Sheng, Z. M.

2018-04-01

A new mechanism of harmonics generation (HG) induced by quantum electrodynamics (QED) effects in extreme intense laser foil interaction is found and investigated by particle-in-cell (PIC) simulations. When two laser pulses with identical intensities of 1.6× {10}24 {{W}} {{{cm}}}-2 are counter-incident on a thin foil target, harmonics emission is observed in their reflected electromagnetic waves. Such harmonics radiation is excited due to transversely oscillating electric currents coming from the vibration of QED effect generated {e}-{e}+ pairs. The effects of laser intensity and polarization were studied. By distinguishing the cascade depth of generated photons and pairs, the influence of QED cascades on HG was analyzed. Although the current HG is not an efficient way for radiation source applications, it may provide a unique way to detect the QED processes in the near future ultra-relativistic laser solid interactions.

Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

DOEpatents

Atzmon, M.; Johnson, W.L.; Verhoeven, J.D.

1987-02-03

Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains of powder or the sheets of foil are clad in a container to form a disc. The disc is cold-rolled between the nip of rollers to form a flattened disc. The grains are further elongated by further rolling to form a very thin sheet of a lamellar filamentary structure containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil is thermally treated in oven to form a composite sheet containing metastable material dispersed in unreacted polycrystalline material. 4 figs.

Highly efficient growth of vertically aligned carbon nanotubes on Fe-Ni based metal alloy foils for supercapacitors

NASA Astrophysics Data System (ADS)

Amalina Raja Seman, Raja Noor; Asyadi Azam, Mohd; Ambri Mohamed, Mohd

2016-12-01

Supercapacitors are highly promising energy devices with superior charge storage performance and a long lifecycle. Construction of the supercapacitor cell, especially electrode fabrication, is critical to ensure good performance in applications. This work demonstrates direct growth of vertically aligned carbon nanotubes (CNTs) on Fe-Ni based metal alloy foils, namely SUS 310S, Inconel 600 and YEF 50, and their use in symmetric vertically aligned CNT supercapacitor electrodes. Alumina and cobalt thin film catalysts were deposited onto the foils, and then CNT growth was performed using alcohol catalytic chemical vapour deposition. By this method, vertically aligned CNTs were successfully grown and used directly as a binder-free supercapacitor electrode to deliver excellent electrochemical performance. The device showed relatively good specific capacitance, a superior rate capability and excellent cycle stability, maintaining about 96% capacitance up to 1000 cycles.

A flexible, high-performance magnetoelectric heterostructure of (001) oriented Pb(Zr0.52Ti0.48)O3 film grown on Ni foil

NASA Astrophysics Data System (ADS)

Palneedi, Haribabu; Yeo, Hong Goo; Hwang, Geon-Tae; Annapureddy, Venkateswarlu; Kim, Jong-Woo; Choi, Jong-Jin; Trolier-McKinstry, Susan; Ryu, Jungho

2017-09-01

In this study, a flexible magnetoelectric (ME) heterostructure of PZT/Ni was fabricated by depositing a (001) oriented Pb(Zr0.52Ti0.48)O3 (PZT) film on a thin, flexible Ni foil buffered with LaNiO3/HfO2. Excellent ferroelectric properties and large ME voltage coefficient of 3.2 V/cmṡOe were realized from the PZT/Ni heterostructure. The PZT/Ni composite's high performance was attributed to strong texturing of the PZT film, coupled with the compressive stress in the piezoelectric film. Besides, reduced substrate clamping in the PZT film due to the film on the foil structure and strong interfacial bonding in the PZT/LaNiO3/HfO2/Ni heterostructure could also have contributed to the high ME performance of PZT/Ni.

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, B. J., E-mail: peterson@LHD.nifs.ac.jp; Mukai, K.; SOKENDAI

2016-11-15

The infrared imaging video bolometer (IRVB) measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 × 480 (1280 × 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm × 9 cm × 2 μm Pt foil. The foil is divided into 40 × 40 (64 × 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) μW/cm{sup 2} for a timemore » resolution of 33 (20) ms. Synthetic images derived from Scrape Off Layer Plasma Simulation data using the IRVB geometry show peak signal levels ranging from ∼0.8 to ∼80 (∼0.36 to ∼26) mW/cm{sup 2}.« less

Preliminary design of a tangentially viewing imaging bolometer for NSTX-U

DOE PAGES

Peterson, B. J.; Sano, R.; Reinke, M. L.; ...

2016-08-03

The InfraRed imaging Video Bolometer measures plasma radiated power images using a thin metal foil. Two different designs with a tangential view of NSTX-U are made assuming a 640 x 480 (1280 x 1024) pixel, 30 (105) fps, 50 (20) mK, IR camera imaging the 9 cm x 9 cm x 2 μm Pt foil. The foil is divided into 40 x 40 (64 x 64) IRVB channels. This gives a spatial resolution of 3.4 (2.2) cm on the machine mid-plane. The noise equivalent power density of the IRVB is given as 113 (46) μW/cm 2 for a time resolutionmore » of 33 (20) ms. Synthetic images derived from SOLPS data using the IRVB geometry show peak signal levels ranging from ~0.8 - ~80 (~0.36 - ~26) mW/cm 2.« less

Solid-state lithium battery

DOEpatents

Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

2014-11-04

The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

Compliant Foil Journal Bearing Performance at Alternate Pressures and Temperatures

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; Puleo, Bernadette J.

2008-01-01

An experimental test program has been conducted to determine the highly loaded performance of current generation gas foil bearings at alternate pressures and temperatures. Typically foil bearing performance has been reported at temperatures relevant to turbomachinery applications but only at an ambient pressure of one atmosphere. This dearth of data at alternate pressures has motivated the current test program. Two facilities were used in the test program, the ambient pressure rig and the high pressure rig. The test program utilized a 35 mm diameter by 27 mm long foil journal bearing having an uncoated Inconel X-750 top foil running against a shaft with a PS304 coated journal. Load capacity tests were conducted at 3, 6, 9, 12, 15, 18, and 21 krpm at temperatures from 25 to 500 C and at pressures from 0.1 to 2.5 atmospheres. Results show an increase in load capacity with increased ambient pressure and a reduction in load capacity with increased ambient temperature. Below one-half atmosphere of ambient pressure a dramatic loss of load capacity is experienced. Additional lightly loaded foil bearing performance in nitrogen at 25 C and up to 48 atmospheres of ambient pressure has also been reported. In the lightly loaded region of operation the power loss increases for increasing pressure at a fixed load. Knowledge of foil bearing performance at operating conditions found within potential machine applications will reduce program development risk of future foil bearing supported turbomachines.

A simple algorithm for beam profile diagnostics using a thermographic camera

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katagiri, Ken; Hojo, Satoru; Honma, Toshihiro

2014-03-15

A new algorithm for digital image processing apparatuses is developed to evaluate profiles of high-intensity DC beams from temperature images of irradiated thin foils. Numerical analyses are performed to examine the reliability of the algorithm. To simulate the temperature images acquired by a thermographic camera, temperature distributions are numerically calculated for 20 MeV proton beams with different parameters. Noise in the temperature images which is added by the camera sensor is also simulated to account for its effect. Using the algorithm, beam profiles are evaluated from the simulated temperature images and compared with exact solutions. We find that niobium ismore » an appropriate material for the thin foil used in the diagnostic system. We also confirm that the algorithm is adaptable over a wide beam current range of 0.11–214 μA, even when employing a general-purpose thermographic camera with rather high noise (ΔT{sub NETD} ≃ 0.3 K; NETD: noise equivalent temperature difference)« less

Impact of the De-Alloying Kinetics and Alloy Microstructure on the Final Morphology of De-Alloyed Meso-Porous Metal Films

PubMed Central

Lin, Bao; Kong, Lingxue; Hodgson, Peter D.; Dumée, Ludovic F.

2014-01-01

Nano-textured porous metal materials present unique surface properties due to their enhanced surface energy with potential applications in sensing, molecular separation and catalysis. In this paper, commercial alloy foils, including brass (Cu85Zn15 and Cu70Zn30) and white gold (Au50Ag50) foils have been chemically de-alloyed to form nano-porous thin films. The impact of the initial alloy micro-structure and number of phases, as well as chemical de-alloying (DA) parameters, including etchant concentration, time and solution temperature on the final nano-porous thin film morphology and properties were investigated by electron microscopy (EM). Furthermore, the penetration depth of the pores across the alloys were evaluated through the preparation of cross sections by focus ion beam (FIB) milling. It is demonstrated that ordered pores ranging between 100 nm and 600 nm in diameter and 2–5 μm in depth can be successfully formed for the range of materials tested. The microstructure of the foils were obtained by electron back-scattered diffraction (EBSD) and linked to development of pits across the material thickness and surface during DA. The role of selective etching of both noble and sacrificial metal phases of the alloy were discussed in light of the competitive surface etching across the range of microstructures and materials tested. PMID:28344253

Bimorph material/structure designs for high sensitivity flexible surface acoustic wave temperature sensors.

PubMed

Tao, R; Hasan, S A; Wang, H Z; Zhou, J; Luo, J T; McHale, G; Gibson, D; Canyelles-Pericas, P; Cooke, M D; Wood, D; Liu, Y; Wu, Q; Ng, W P; Franke, T; Fu, Y Q

2018-06-13

A fundamental challenge for surface acoustic wave (SAW) temperature sensors is the detection of small temperature changes on non-planar, often curved, surfaces. In this work, we present a new design methodology for SAW devices based on flexible substrate and bimorph material/structures, which can maximize the temperature coefficient of frequency (TCF). We performed finite element analysis simulations and obtained theoretical TCF values for SAW sensors made of ZnO thin films (~5 μm thick) coated aluminum (Al) foil and Al plate substrates with thicknesses varied from 1 to 1600 μm. Based on the simulation results, SAW devices with selected Al foil or plate thicknesses were fabricated. The experimentally measured TCF values were in excellent agreements with the simulation results. A normalized wavelength parameter (e.g., the ratio between wavelength and sample thickness, λ/h) was applied to successfully describe changes in the TCF values, and the TCF readings of the ZnO/Al SAW devices showed dramatic increases when the normalized wavelength λ/h was larger than 1. Using this design approach, we obtained the highest reported TCF value of -760 ppm/K for a SAW device made of ZnO thin film coated on Al foils (50 μm thick), thereby enabling low cost temperature sensor applications to be realized on flexible substrates.

Manufacturing and characterization of magnesium alloy foils for use as anode materials in rechargeable magnesium ion batteries

NASA Astrophysics Data System (ADS)

Schloffer, Daniel; Bozorgi, Salar; Sherstnev, Pavel; Lenardt, Christian; Gollas, Bernhard

2017-11-01

The fabrication of thin foils of magnesium for use as anode material in rechargeable magnesium ion batteries is described. In order to improve its workability, the magnesium was alloyed by melting metallurgy with zinc and/or gadolinium, producing saturated solid solutions. The material was extruded to thin foils and rolled to a thickness of approximately 100 μm. The electrochemical behavior of Mg-1.63 wt% Zn, Mg-1.55 wt% Gd and Mg-1.02 wt% Zn-1.01 wt% Gd was studied in (PhMgCl)2-AlCl3/THF electrolyte by cyclic voltammetry and galvanostatic cycling in symmetrical cells. Analysis of the current-potential curves in the Tafel region and the linear region close to the equilibrium potential show almost no effect of the alloying elements on the exchange current densities (5-45 μA/cm2) and the transfer coefficients. Chemical analyses of the alloy surfaces and the electrolyte demonstrate that the alloying elements not only dissolve with the magnesium during the anodic half-cycles, but also re-deposit during the cathodic half-cycles together with the magnesium and aluminum from the electrolyte. Given the negligible corrosion rate in aprotic electrolytes under such conditions, no adverse effects of alloying elements are expected for the performance of magnesium anodes in secondary batteries.

Probing of high density plasmas using the multi-beam, high power TiSa laser system ARCTURUS

NASA Astrophysics Data System (ADS)

Willi, Oswald; Aktan, Esin; Brauckmann, Stephannie; Aurand, Bastian; Cerchez, Mirela; Prasad, Rajendra; Schroer, Anna Marie

2017-10-01

The understanding of relativistic laser plasma interaction at ultra-high intensities has advanced considerably during the last decade with the availability of multi-beam, high power TiSa laser systems. These laser systems allow pump-probe experiments to be carried out. The ARCTURUS laser at the University of Duesseldorf is ideally suited for various kinds of pump-probe experiments as it consists of two identical, high power beams with energies of 5J in 30 fs and a third beam for optical probing with energy of 30mJ in a 30fs pulse. All three beams are synchronised and have flexible time delays with respect to each other. Several different processes were studied where one of the beams was used as an interaction beam and the second one was incident on a thin solid gold foil to generate a proton beam. For example, thin foil targets were irradiated either with a linear or circular polarized pulse and probed with protons at different times. The expansion of foils for the two cases was clearly different consistent with numerical simulations. In addition, the interaction of gas targets was probed with protons and separately with an optical probe. With both diagnostics the formation of a channel was observed. In the presentation various two beam measurements will be discussed.

Initial experimental evidence of self-collimation of target-normal-sheath-accelerated proton beam in a stack of conducting foils

NASA Astrophysics Data System (ADS)

Ni, P. A.; Lund, S. M.; McGuffey, C.; Alexander, N.; Aurand, B.; Barnard, J. J.; Beg, F. N.; Bellei, C.; Bieniosek, F. M.; Brabetz, C.; Cohen, R. H.; Kim, J.; Neumayer, P.; Roth, M.; Logan, B. G.

2013-08-01

Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated protons was experimentally observed for the first time, in a specially engineered structure ("lens") consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. The experiments were carried out in a "passive environment," i.e., no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt "PHELIX" laser user facility (E = 100 J, Δt = 400 fs, λ = 1062 nm) at the "Helmholtzzentrum für Schwerionenforschung-GSI" in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a Linear Accelerator (LINAC) or synchrotron, medical therapy, materials processing, etc.

Initial experimental evidence of self-collimation of TNSA proton beam in a stack of conducting foils

NASA Astrophysics Data System (ADS)

Ni, Pavel

2013-10-01

Phenomena consistent with self-collimation (or weak self-focusing) of laser target-normal-sheath-accelerated (TNSA) protons was experimentally observed for the first time, in a specially engineered structure (``lens'') consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. The experiments were carried out in a ``passive environment,'' i.e. no external fields applied, neutralization plasma or injection of secondary charged particles was imposed. Experiments were performed at the petawatt ``PHELIX'' laser user facility (E = 100 J, Δt = 400 fs, λ = 1062 nm) at the ``Helmholtzzentrum für Schwerionenforschung-GSI'' in Darmstadt, Germany. The observed rms beam spot reduction depends inversely on energy, with a focusing degree decreasing monotonically from 2 at 5.4 MeV to 1.5 MeV at 18.7 MeV. The physics inside the lens is complex, resulting in a number of different mechanisms that can potentially affect the particle dynamics within the structure. We present a plausible simple interpretation of the experiment in which the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the foils are the dominant mechanisms responsible for the observed focusing/collimation. This focusing technique could be applied to a wide variety of space-charge dominated proton and heavy ion beams and impact fields and applications, such as HEDP science, inertial confinement fusion in both fast ignition and heavy ion fusion approaches, compact laser-driven injectors for a LINAC or synchrotron, medical therapy, materials processing, etc.

Nuclear track-based biosensors with the enzyme laccase

NASA Astrophysics Data System (ADS)

García-Arellano, H.; Fink, D.; Muñoz Hernández, G.; Vacík, J.; Hnatowicz, V.; Alfonta, L.

2014-08-01

A new type of biosensors for detecting phenolic compounds is presented here. These sensors consist of thin polymer foils with laccase-clad etched nuclear tracks. The presence of suitable phenolic compounds in the sensors leads to the formation of enzymatic reaction products in the tracks, which differ in their electrical conductivities from their precursor materials. These differences correlate with the concentrations of the phenolic compounds. Corresponding calibration curves have been established for a number of compounds. The sensors thus produced are capable to cover between 5 and 9 orders of magnitude in concentration - in the best case down to some picomoles. The sensor's detection sensitivity strongly depends on the specific compound. It is highest for caffeic acid and acid blue 74, followed by ABTS and ferulic acid.

Effect of input perturbation on the performance and wake dynamics of aquatic propulsion in heaving flexible foils

NASA Astrophysics Data System (ADS)

Lehn, Andrea M.; Thornycroft, Patrick J. M.; Lauder, George V.; Leftwich, Megan C.

2017-02-01

In this paper we consider the effects of adding high-frequency, low-amplitude perturbations to a smooth sinusoidal base input signal for a heaving panel in a closed loop flow tank. Specifically, 0.1 cm amplitude sinusoidal perturbation waves with frequency fp ranging from 0.5 to 13.0 Hz are added to 1 cm heave sinusoids with base frequencies, fb, ranging from 0.5 to 3.0 Hz. Two thin foils with different flexural stiffness are heaved with the combined input signals in addition to both the high-heave and low-heave signals independently. In all cases, the foils are heaved in a recirculating water channel with an incoming velocity of Vx=10 cm/s and a Reynolds number based on the chord length of Re=17 300 . Results demonstrate that perturbations increase the net axial force, in the streamwise direction, in most cases tested (with the exception of some poor performing flexible foil cases). Most significantly, for a base frequency of 1 Hz, perturbations at 9 Hz result in a 780.7% increase in net streamwise force production. Generally, the higher the perturbation frequency, fp the more axial force generated. However, for the stiffer foil, a clear peak in net force exists at fp=9 Hz , regardless of the base frequency. For the stiffer foil, swimming efficiency at a 1 Hz flapping frequency is increased dramatically with the addition of a perturbation, with reduced efficiency increases at higher flapping frequencies. Likewise, for the flexible foil, swimming efficiency gains are greatest at the lower flapping frequencies. Perturbations alter the wake structure by increasing the vorticity magnitude and increasing the vortex shedding frequency; i.e., more, stronger vortices are produced in each flapping cycle.

Method of making a partial interlaminar separation composite system

NASA Technical Reports Server (NTRS)

Elber, W. (Inventor)

1981-01-01

An interlaminar separation system for composites is disclosed a thin layer of a perforated foil film is interposed between adjacent laminae of a composite formed from prepreg tapes. Laminae adherence takes place through the perforations and a composite structure with improved physical property characteristics is produced.

High temperature pressure coupled ultrasonic waveguide

DOEpatents

Caines, Michael J.

1983-01-01

A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

High-temperature pressure-coupled ultrasonic waveguide

DOEpatents

Caines, M.J.

1981-02-11

A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

Partial interlaminar separation system for composites

NASA Technical Reports Server (NTRS)

Elber, W. (Inventor)

1980-01-01

This inventor relates to an interlaminar separation system for composites wherein a thin layer of a perforated foil film is interposed between adjacent laminae of a composite formed from prepreg tapes to thereby permit laminate adherence through the perforations and produce a composite structure having improved physical property characteristics.

Rayleigh-Taylor instability of two-specie laser-accelerated foils

NASA Astrophysics Data System (ADS)

Ratliff, T. H.; Yi, S. A.; Khudik, V.; Yu, T. P.; Pukhov, A.; Chen, M.; Shvets, G.

2010-11-01

When an ultra intense circularly polarized laser pulse irradiates an ultra thin film, a monoenergetic ion beam is produced with characteristics well suited for applications in science and medicine. Upon laser incidence, the electrons in the foil are pushed via the ponderomotive force to the foil rear; the charge separation field then accelerates ions. In the accelerating frame the ions are trapped in a potential well formed by the electrostatic and inertial forces. However, their energy spectrum can be quickly degraded by the Rayleigh-Taylor (RT) instability. Stabilization in the case of a two-specie foil is the subject of this poster. First, we use a 1D particle-in-cell (PIC) simulation to establish an equilibrium state of the two-specie foil in the accelerating frame. Next we perturb this equilibrium and analytically investigate the 2D RT instability. Analytical results are compared with 2-D simulations. We also investigate parametrically various effects on the RT growth rate. The protons completely separate from the carbons, and although the vacuum-carbon interface remains unstable, the large spatial extent of the carbon layer prevents perturbations from feeding through to the proton layer. The monoenergetic proton beam is shown to persist beyond the conclusion of the laser pulse interaction. [1] T.P. Yu, A. Pukhov, G. Shvets, and M Chen, Phys. Rev. Lett. (in press)

Studies of Surface Charging of Polymers by Indirect Triboelectrification

NASA Astrophysics Data System (ADS)

Mantovani, James; Calle, Carlos; Groop, Ellen; Buehler, Martin

2001-03-01

Charge is known to develop on the surface of an insulating polymer by frictional charging through direct physical contact with another material. We will present results of recent triboelectrification studies of polymer surfaces that utilized an indirect method of frictional charging. This method first involves placing a grounded thin metal foil in stationary contact over the polymer surface. The exposed metal foil is then rubbed with the surface of the material that generates the triboelectric charge. Data is presented for five types of polymers: fiberglass/epoxy, polycarbonate (Lexan), polytetraflouroethylene (Teflon), Rulon J, and polymethylmethacrylate (PMMA, Lucite). The amount of charge that develops on an insulator's surface is measured using the MECA Electrometer, which was developed jointly by NASA Kennedy Space Center and the Jet Propulsion Laboratory to study the electrostatic properties of soil on the surface of Mars. Even though the insulator's surface is electrically shielded from the rubbing material by the grounded metal foil, charge measurements obtained by the MECA Electrometer after the metal foil is separated from the insulator's surface reveal that the insulator's surface does accumulate charge by indirect frictional charging. A possible explanation of the observations will be presented based on a simple contact barrier model.

Chromatic Titanium Photoanode for Dye-Sensitized Solar Cells under Rear Illumination.

PubMed

Huang, Chih-Hsiang; Chen, Yu-Wen; Chen, Chih-Ming

2018-01-24

Titanium (Ti) has high potential in many practical applications such as biomedicine, architecture, aviation, and energy. In this study, we demonstrate an innovative application of dye-sensitized solar cells (DSSCs) based on Ti photoanodes that can be integrated into the roof engineering of large-scale architectures. A chromatic Ti foil produced by anodizing oxidation (coloring) technology is an attractive roof material for large-scale architecture, showing a colorful appearance due to the formation of a reflective TiO 2 thin layer on both surfaces of Ti. The DSSC is fabricated on the backside of the chromatic Ti foil using the Ti foil as the working electrode, and this roof-DSSC hybrid configuration can be designed as an energy harvesting device for indoor artificial lighting. Our results show that the facet-textured TiO 2 layer on the chromatic Ti foil not only improves the optical reflectance for better light utilization but also effectively suppresses the charge recombination for better electron collection. The power conversion efficiency of the roof-DSSC hybrid system is improved by 30-40% with a main contribution from an improvement of short-circuit current density under standard 1 sun and dim-light (600-1000 lx) illumination.

Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils

NASA Astrophysics Data System (ADS)

Osman, H.; Borhana, A.; Tamin, M. N.

2014-08-01

Creep rupture properties of austenitic stainless steel foil, 347SS, used in compact recuperators have been evaluated at 700 °C in the stress range of 54-221 MPa to establish the baseline behavior for its extended use. Creep curves of the foil show that the primary creep stage is brief and creep life is dominated by tertiary creep deformation with rupture lives in the range of 10-2000 h. Results are compared with properties of bulk specimens tested at 98 and 162 MPa. Thin foil 347SS specimens were found to have higher creep rates and higher rupture ductility than their bulk specimen counterparts. Power law relationship was obtained between the minimum creep rate and the applied stress with stress exponent value, n = 5.7. The value of the stress exponent is indicative of the rate-controlling deformation mechanism associated with dislocation creep. Nucleation of voids mainly occurred at second-phase particles (chromium-rich M23C6 carbides) that are present in the metal matrix by decohesion of the particle-matrix interface. The improvement in strength is attributed to the precipitation of fine niobium carbides in the matrix that act as obstacles to the movement of dislocations.

High density plasma gun generates plasmas at 190 kilometers per second

NASA Technical Reports Server (NTRS)

Espy, P. N.

1971-01-01

Gun has thin metal foil disc which positions or localizes gas to be ionized during electrical discharge cycle, overcoming major limiting factor in obtaining such plasmas. Expanding plasma front travels at 190 km/sec, compared to plasmas of 50 to 60 km/sec previously achieved.

Method and system for making integrated solid-state fire-sets and detonators

DOEpatents

O'Brien, Dennis W.; Druce, Robert L.; Johnson, Gary W.; Vogtlin, George E.; Barbee, Jr., Troy W.; Lee, Ronald S.

1998-01-01

A slapper detonator comprises a solid-state high-voltage capacitor, a low-jitter dielectric breakdown switch and trigger circuitry, a detonator transmission line, an exploding foil bridge, and a flier material. All these components are fabricated in a single solid-state device using thin film deposition techniques.

Erosion of mylar and protection by thin metal films

NASA Technical Reports Server (NTRS)

Fraundorf, P.; Lindstrom, D.; Sandford, S.; Swan, P.; Walker, R.; Zinner, E.; Pailer, N.

1983-01-01

Mylar strips, 2.5 microns thick, uncoated and coated with 50A, 100A and 200A of Al, Pd, and Au/Pd were exposed on STS-5 in order to measure the erosion of mylar and to test means of protecting thin plastic foils commonly used for space experiments in low earth orbit. Analysis by optical microscopy, SEM and STEM investigation, EDX measurements, FTIR spectroscopy and weight loss measurements showed that while up to 75 percent of the uncoated mylar was eroded during exposure, thin coatings of the above metals can protect mylar for integrated oxygen-fluxes of at least 10 to the 21st atoms/sq cm.

A dilute Cu(Ni) alloy for synthesis of large-area Bernal stacked bilayer graphene using atmospheric pressure chemical vapour deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madito, M. J.; Bello, A.; Dangbegnon, J. K.

2016-01-07

A bilayer graphene film obtained on copper (Cu) foil is known to have a significant fraction of non-Bernal (AB) stacking and on copper/nickel (Cu/Ni) thin films is known to grow over a large-area with AB stacking. In this study, annealed Cu foils for graphene growth were doped with small concentrations of Ni to obtain dilute Cu(Ni) alloys in which the hydrocarbon decomposition rate of Cu will be enhanced by Ni during synthesis of large-area AB-stacked bilayer graphene using atmospheric pressure chemical vapour deposition. The Ni doped concentration and the Ni homogeneous distribution in Cu foil were confirmed with inductively coupledmore » plasma optical emission spectrometry and proton-induced X-ray emission. An electron backscatter diffraction map showed that Cu foils have a single (001) surface orientation which leads to a uniform growth rate on Cu surface in early stages of graphene growth and also leads to a uniform Ni surface concentration distribution through segregation kinetics. The increase in Ni surface concentration in foils was investigated with time-of-flight secondary ion mass spectrometry. The quality of graphene, the number of graphene layers, and the layers stacking order in synthesized bilayer graphene films were confirmed by Raman and electron diffraction measurements. A four point probe station was used to measure the sheet resistance of graphene films. As compared to Cu foil, the prepared dilute Cu(Ni) alloy demonstrated the good capability of growing large-area AB-stacked bilayer graphene film by increasing Ni content in Cu surface layer.« less

A dilute Cu(Ni) alloy for synthesis of large-area Bernal stacked bilayer graphene using atmospheric pressure chemical vapour deposition

NASA Astrophysics Data System (ADS)

Madito, M. J.; Bello, A.; Dangbegnon, J. K.; Oliphant, C. J.; Jordaan, W. A.; Momodu, D. Y.; Masikhwa, T. M.; Barzegar, F.; Fabiane, M.; Manyala, N.

2016-01-01

A bilayer graphene film obtained on copper (Cu) foil is known to have a significant fraction of non-Bernal (AB) stacking and on copper/nickel (Cu/Ni) thin films is known to grow over a large-area with AB stacking. In this study, annealed Cu foils for graphene growth were doped with small concentrations of Ni to obtain dilute Cu(Ni) alloys in which the hydrocarbon decomposition rate of Cu will be enhanced by Ni during synthesis of large-area AB-stacked bilayer graphene using atmospheric pressure chemical vapour deposition. The Ni doped concentration and the Ni homogeneous distribution in Cu foil were confirmed with inductively coupled plasma optical emission spectrometry and proton-induced X-ray emission. An electron backscatter diffraction map showed that Cu foils have a single (001) surface orientation which leads to a uniform growth rate on Cu surface in early stages of graphene growth and also leads to a uniform Ni surface concentration distribution through segregation kinetics. The increase in Ni surface concentration in foils was investigated with time-of-flight secondary ion mass spectrometry. The quality of graphene, the number of graphene layers, and the layers stacking order in synthesized bilayer graphene films were confirmed by Raman and electron diffraction measurements. A four point probe station was used to measure the sheet resistance of graphene films. As compared to Cu foil, the prepared dilute Cu(Ni) alloy demonstrated the good capability of growing large-area AB-stacked bilayer graphene film by increasing Ni content in Cu surface layer.

SR-XRD and SR-FTIR study of the alteration of silver foils in medieval paintings.

PubMed

Salvadó, Nati; Butí, Salvador; Labrador, Ana; Cinque, Gianfelice; Emerich, Hermann; Pradell, Trinitat

2011-03-01

Altarpieces and polychrome carved wood from the fifteenth century AD usually exhibit golden and silvery areas by the application of a very thin foil of metal. The metal foils were normally protected from the atmosphere by a varnish or resin which maybe either preserved or absent. Moreover, they were glued to the background surface by adhesive substances (egg yolk, drying oil or animal glue). The high proportion of the glueing substances often renders the development of reaction compounds. With time, silver alters blacken or simply disappear completely. In this paper, we study the alterations to metal foils from a selection of fifteenth century artworks showing different glueing agents, organic coatings and several degrees of conservation of the organic coatings and metal leafs. The submillimetric layered structure and the high variability and low amount of most of the compounds present in the different layers, as well as their differing nature (organic and inorganic) make the use of micron-sensitive high-resolution techniques essential for their study. In particular, the high resolution, high brilliance and small footprint renders synchrotron radiation most adequate for their study. SR-XRD was performed to identify the reaction compounds formed in the different layers; μFTIR was used at to identify the silver protecting organic coatings, the metal foil glueing layers and the corresponding reaction compounds. The results obtained suggest that atmospheric corrosion is the dominant mechanism, and therefore that the degree of corrosion of the metal foils is mainly related to the conservation state of the protecting coatings.

Thermal Analysis and Design of Multi-layer Insulation for Re-entry Aerodynamic Heating

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

2001-01-01

The combined radiation/conduction heat transfer in high-temperature multi-layer insulations was modeled using a finite volume numerical model. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements, and by transient thermal tests simulating re-entry aerodynamic heating conditions. A design of experiments technique was used to investigate optimum design of multi-layer insulations for re-entry aerodynamic heating. It was found that use of 2 mm foil spacing and locating the foils near the hot boundary with the top foil 2 mm away from the hot boundary resulted in the most effective insulation design. A 76.2 mm thick multi-layer insulation using 1, 4, or 16 foils resulted in 2.9, 7.2, or 22.2 percent mass per unit area savings compared to a fibrous insulation sample at the same thickness, respectively.

Enhanced Reduction of Graphene Oxide on Recyclable Cu Foils to Fabricate Graphene Films with Superior Thermal Conductivity

PubMed Central

Huang, Sheng-Yun; Zhao, Bo; Zhang, Kai; Yuen, Matthew M. F.; Xu, Jian-Bin; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

2015-01-01

Large-area freestanding graphene films are facilely fabricated by reducing graphene oxide films on recyclable Cu foils in H2-containing atmosphere at high temperature. Cu might act as efficient catalysts for considerably improved reduction of graphene oxide according to the SEM, EDS, XRD, XPS, Raman and TGA results. Comparing to the graphene films with ~30 μm thickness reduced without Cu substrate at 900 °C, the thermal conductivity and electrical conductivity of graphene films reduced on Cu foils are enhanced about 140% to 902 Wm−1K−1 and 3.6 × 104 S/m, respectively. Moreover, the graphene films demonstrate superior thermal conductivity of ~1219 Wm−1K−1 as decreasing the thickness of films to ~10 μm. The graphene films also exhibit excellent mechanical properties and flexibility. PMID:26404674

Foil cooling for rep-rated electron beam pumped KrF lasers

NASA Astrophysics Data System (ADS)

Giuliani, J. L.; Hegeler, F.; Sethian, J. D.; Wolford, M. F.; Myers, M. C.; Abdel-Khalik, S.; Sadowski, D.; Schoonover, K.; Novak, V.

2006-06-01

In rep-rated electron beam pumped lasers the foil separating the vacuum diode from the laser gas is subject to repeated heating due to partial beam stopping. Three cooling methods are examined for the Electra KrF laser at the Naval Research Laboratory (NRL). Foil temperature measurements for convective cooling by the recirculating laser gas and by spray mist cooling are reported, along with estimates for thermal conductive foil cooling to the hibachi ribs. Issues on the application of each of these approaches to laser drivers in a fusion power plant are noted. Work supported by DOE/NNSA.

Neutron sensitivity of 6Li-based suspended foil microstrip neutron detectors using Schott Borofloat® 33 microstrip electrodes

NASA Astrophysics Data System (ADS)

Edwards, Nathaniel S.; Montag, Benjamin W.; Henson, Luke C.; Bellinger, Steven L.; Nichols, Daniel M.; Reichenberger, Michael A.; Fronk, Ryan G.; McGregor, Douglas S.

2018-06-01

6Li foils, each 75-μm thick, were positioned between a Schott Borofloat® 33 microstrip electrode and a planar drift electrode to construct suspended foil microstrip neutron detectors. MCNP6 simulations of two detector configurations, one containing a single 6Li foil and the other containing five 6Li foils, indicated expected maximum intrinsic thermal-neutron detection efficiencies of 18.36% and 54.08%, respectively. For comparison, the intrinsic thermal-neutron detection efficiency as a function of thermal-neutron beam position along the foil span was experimentally measured for both detector configurations. A non-uniform intrinsic thermal-neutron detection efficiency distribution was observed along the span of the 6Li foil(s) between the microstrip and drift electrodes. Maximum intrinsic thermal-neutron detection efficiencies of 12.58 ± 0.15% and 29.75 ± 0.26% for the single and five 6Li foils were measured, respectively. Gamma-ray rejection ratios of 6.46 × 10-5 ± 4.32 × 10-7 and 7.96 × 10-5 ± 4.65 × 10-7 were also measured, respectively, for a 137Cs exposure rate of 50 mR h-1. All measurements were conducted with the 6Li foil(s) contained within a sealed aluminum enclosure pressurized with 10 psig of P-10 gas.

Transient changes in electric fields induced by interaction of ultraintense laser pulses with insulator and metal foils: Sustainable fields spanning several millimeters

NASA Astrophysics Data System (ADS)

Inoue, Shunsuke; Tokita, Shigeki; Hashida, Masaki; Sakabe, Shuji

2015-04-01

The temporal evolutions of electromagnetic fields generated by the interaction between ultraintense lasers (1.3 ×1018 and 8.2 ×1018W /c m2 ) and solid targets at a distance of several millimeters from the laser-irradiated region have been investigated by electron deflectometry. For three types of foil targets (insulating foil, conductive foil, and insulating foil onto which a metal disk was deposited), transient changes in the fields were observed. We found that the direction, strength, and temporal evolution of the generated fields differ markedly for these three types of targets. The results provide an insight for studying the emission dynamics of laser-accelerated fast electrons.

Manufacturing and testing a thin glass mirror shell with piezoelectric active control

NASA Astrophysics Data System (ADS)

Spiga, D.; Barbera, M.; Collura, A.; Basso, S.; Candia, R.; Civitani, M.; Di Bella, M.; Di Cicca, G.; Lo Cicero, U.; Lullo, G.; Pelliciari, C.; Riva, M.; Salmaso, B.; Sciortino, L.; Varisco, S.

2015-09-01

Optics for future X-ray telescopes will be characterized by very large aperture and focal length, and will be made of lightweight materials like glass or silicon in order to keep the total mass within acceptable limits. Optical modules based on thin slumped glass foils are being developed at various institutes, aiming at improving the angular resolution to a few arcsec HEW. Thin mirrors are prone to deform, so they require a careful integration to avoid deformations and even correct forming errors. On the other hand, this offers the opportunity to actively correct the residual deformation: a viable possibility to improve the mirror figure is the application of piezoelectric actuators onto the non-optical side of the mirrors, and several groups are already at work on this approach. The concept we are developing consists of actively integrating thin glass foils with piezoelectric patches, fed by voltages driven by the feedback provided by X-rays. The actuators are commercial components, while the tension signals are carried by a printed circuit obtained by photolithography, and the driving electronic is a multi-channel low power consumption voltage supply developed inhouse. Finally, the shape detection and the consequent voltage signal to be provided to the piezoelectric array are determined in X-rays, in intra-focal setup at the XACT facility at INAF/OAPA. In this work, we describe the manufacturing steps to obtain a first active mirror prototype and the very first test performed in X-rays.

The Effect of Journal Roughness and Foil Coatings on the Performance of Heavily Loaded Foil Air Bearings

NASA Technical Reports Server (NTRS)

Radil, Kevin C.; DellaCorte, Christopher

2001-01-01

Foil air bearing load capacity tests were conducted to investigate if a solid lubricant coating applied to the surface of the bearing's top foil can function as a break-in coating. Two foil coating materials, a conventional soft polymer film (polyimide) and a hard ceramic (alumina), were independently evaluated against as-ground and worn (run-in) journals coated with NASA PS304, a high-temperature solid lubricant composite coating. The foil coatings were evaluated at journal rotational speeds of 30,000 rpm and at 25 C. Tests were also performed on a foil bearing with a bare (uncoated) nickel-based superalloy top foil to establish a baseline for comparison. The test results indicate that the presence of a top foil solid lubricant coating is effective at increasing the load capacity performance of the foil bearing. Compared to the uncoated baseline, the addition of the soft polymer coating on the top foil increased the bearing load coefficient by 120% when operating against an as-ground journal surface and 85 percent against a run-in journal surface. The alumina coating increased the load coefficient by 40% against the as-ground journal but did not have any affect when the bearing was operated with the run-in journal. The results suggest that the addition of solid lubricant films provide added lubrication when the air film is marginal indicating that as the load capacity is approached foil air bearings transition from hydrodynamic to mixed and boundary lubrication.

Subnanosecond measurements of detonation fronts in solid high explosives

NASA Astrophysics Data System (ADS)

Sheffield, S. A.; Bloomquist, D. D.; Tarver, C. M.

1984-04-01

Detonation fronts in solid high explosives have been examined through measurements of particle velocity histories resulting from the interaction of a detonation wave with a thin metal foil backed by a water window. Using a high time resolution velocity-interferometer system, experiments were conducted on three explosives—a TATB (1,3,5-triamino-trinitrobenzene)-based explosive called PBX-9502, TNT (2,4,6-Trinitrotoluene), and CP (2-{5-cyanotetrazolato} pentaamminecobalt {III} perchlorate). In all cases, detonation-front rise times were found to be less than the 300 ps resolution of the interferometer system. The thermodynamic state in the front of the detonation wave was estimated to be near the unreacted state determined from an extrapolation of low-pressure unreacted Hugoniot data for both TNT and PBX-9502 explosives. Computer calculations based on an ignition and growth model of a Zeldovich-von Neumann-Doering (ZND) detonation wave show good agreement with the measurements. By using the unreacted Hugoniot and a JWL equation of state for the reaction products, we estimated the initial reaction rate in the high explosive after the detonation wave front interacted with the foil to be 40 μs-1 for CP, 60 μs-1 for TNT, and 80 μs-1 for PBX-9502. The shape of the profiles indicates the reaction rate decreases as reaction proceeds.

PEN as self-vetoing structural material

NASA Astrophysics Data System (ADS)

Majorovits, B.; Eck, S.; Fischer, F.; Gooch, C.; Hayward, C.; Kraetzschmar, T.; van der Kolk, N.; Muenstermann, D.; Schulz, O.; Simon, F.

2018-01-01

Polyethylene Naphtalate (PEN) is a mechanically very favorable polymer. Earlier it was found that thin foils made from PEN can have very high radio-purity compared to other commercially available foils. In fact, PEN is already in use for low background signal transmission applications (cables). Recently it has been realized that PEN also has favorable scintillating properties. In combination, this makes PEN a very promising candidate as a self-vetoing structural material in low background experiments. Components instrumented with light detectors could be built from PEN. This includes detector holders, detector containments, signal transmission links, etc. The current R&D towards qualification of PEN as a self-vetoing low background structural material is be presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Bo; Yao, Shurong; Nie, Xu

In this paper, a new type of highly stretchable strain sensor was developed to measure large strains. The sensor was based on the piezo-resistive response of carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite thin films. The piezo-resistive response of CNT composite gives accurate strain measurement with high frequency response, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measurement. Experimental results show that the CNT/PDMS sensor measures large strains (up to 8 %) with an excellent linearity and a fast frequency response. The new miniature strain sensor also exhibits much higher sensitivities than the conventional foil strain gages,more » as its gauge factor is 500 times of that of the conventional foil strain gages.« less

A flexible top-emitting organic light-emitting diode on steel foil

NASA Astrophysics Data System (ADS)

Xie, Zhiyuan; Hung, Liang-Sun; Zhu, Furong

2003-11-01

An efficient flexible top-emitting organic light-emitting diode (FTOLED) was developed on a thin steel foil. The FTOLED was constructed on the spin-on-glass (SOG)-coated steel substrate with an organic stack of NPB/Alq 3 sandwiched by a highly reflective Ag anode and a semitransparent Sm cathode. An ultrathin plasma-polymerized hydrocarbon film (CF X) was interposed between the Ag anode and the NPB layer to enhance hole-injection, and an additional Alq 3 layer was overlaid on the Sm cathode to increase light output. The FTOLED showed a peak efficiency of 4.4 cd/A higher than 3.7 cd/A of a convention NPB/Alq 3-based bottom-emitting OLED.

Preparation of graphene thin films for radioactive samples.

PubMed

Roteta, Miguel; Fernández-Martínez, Rodolfo; Mejuto, Marcos; Rucandio, Isabel

2016-03-01

A new method for the preparation of conductive thin films is presented. The metallization of VYNS films guarantees the electrical conductivity but it results in the breaking of a high proportion of them. Graphene, a two-dimensional nanostructure of monolayer or few layers graphite has attracted a great deal of attention because of its excellent properties such as a good chemical stability, mechanical resistance and extraordinary electronic transport properties. In this work, the possibilities of graphene have been explored as a way to produce electrical conductive thin films without an extra metallization process. The procedure starts with preparing homogenous suspensions of reduced graphene oxide (rGO) in conventional VYNS solutions. Ultra-sonication is used to ensure a good dispersibility of rGO. Graphene oxide (GO) is prepared via oxidation of graphite and subsequent exfoliation by sonication. Different chemically rGO were obtained by reaction with hydrazine sulfate, sodium borohydride, ascorbic acid and hydroiodic acid as reducing agents. The preparation of the thin graphene films is done in a similar way as the conventional VYNS foil preparation procedure. Drops of the solution are deposited onto water. The graphene films have been used to prepare sources containing some electron capture radionuclides ((109)Cd, (55)Fe, (139)Ce) with an activity in the order of 3kBq. The samples have been measured to test the attainable low energy electron efficiency and the energy resolution of Auger and conversion electrons by 4π (electron capture)-γ coincidence measurements. The 4π (electron capture)-γ coincidence setup includes a pressurized proportional counter and a NaI(Tl) detector. Tests with different pressures up to 1000kPa were carried out. All these tests show similar values in both parameters (efficiency and resolution) as those obtained by using the conventional metallized films without the drawback of the high percentage of broken films. Copyright © 2015 Elsevier Ltd. All rights reserved.

Examinations on Laser Remote Welding of Ultra-thin Metal Foils Under Vacuum Conditions

NASA Astrophysics Data System (ADS)

Petrich, Martin; Stambke, Martin; Bergmann, Jean Pierre

Metal foils are commonly used for catalytic converters, vacuum insulations, in medical and electrical industry as well as for sensor applications and packaging. The investigations in this paper determine the influence of reduced atmospheric pressure during the welding process with a highly brilliant 400 W single-mode fiber laser combined with a 2D-scanning system. The laser beam is transmitted through a highly transparent glass into a vacuum chamber, where AISI 304 stainless steel foils with a thickness of 25 μm, 50 μm and 100 μm are positioned. The effects of reduced atmospheric pressure on the plasma formation are investigated by means of high-speed videography. Furthermore, the geometry of the weld seam is compared to atmospheric conditions as well as means of the process stability and the process efficiency. The welds were also evaluated by means of metallography. The research is a contribution for extending the range of micro welding applications and shows new aspects for future developments.

Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

DOEpatents

Atzmon, Michael; Johnson, William L.; Verhoeven, John D.

1987-01-01

Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains (13) of powder or the sheets of foil are clad in a container (14) to form a disc (10). The disc (10) is cold-rolled between the nip (16) of rollers (18,20) to form a flattened disc (22). The grains (13) are further elongated by further rolling to form a very thin sheet (26) of a lamellar filamentary structure (FIG. 4) containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil (28) is thermally treated in oven (32) to form a composite sheet (33) containing metastable material (34) dispersed in unreacted polycrystalline material (36).

Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil.

PubMed

Kappen, P; Arhatari, B D; Luu, M B; Balaur, E; Caradoc-Davies, T

2013-06-01

This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography∕diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).

In-situ grown nanoporous Zn-Cu catalysts on brass foils for enhanced electrochemical reduction of carbon dioxide

NASA Astrophysics Data System (ADS)

Hu, Hanjun; Tang, Yang; Hu, Qing; Wan, Pingyu; Dai, Liming; Yang, Xiao Jin

2018-07-01

In-situ grown nanoporous Zn-Cu catalysts were prepared by simply annealing a commercial brass foil at 500 °C in air, followed by electrochemical reduction. During the annealing process, Zn preferentially melted and migrated out of the framework of the alloy to form a thin layer of ZnO on its surface. Subsequent electroreduction created nanoporous Zn-enriched surface. The Zn concentration increased from 36% to 50% by 10 min, to 81% by 3 h, and to 87% by 12 h annealing treatment while the average pore size decreased from 290 nm to 120 nm as the annealing time increased from 1 h to 12 h. Faradaic efficiency of CO2 reduction to CO and HCOOH was enhanced by nearly 4 and 6 times, respectively, as compared to untreated brass foils. The nanoporous Zn-Cu catalyst presented a stable ratio of CO/H2 and a steady working current density in a continuous electrolysis of 18 h in 0.5 M KHCO3 solution.

The piezoresistive effect in graphene-based polymeric composites.

PubMed

Tamburrano, A; Sarasini, F; De Bellis, G; D'Aloia, A G; Sarto, M S

2013-11-22

The strain-dependent electrical resistance of polyvinyl ester-based composites filled with different weight fractions of graphene nanoplatelets (GNPs) has been experimentally investigated. The GNP synthesis and nanocomposite fabrication process have been optimized in order to obtain highly homogeneous filler dispersion and outstanding electrical properties. The produced nanocomposites showed a low percolation threshold of 0.226 wt% and electrical conductivity of nearly 10 S m(-1) at only 4 wt% of GNPs. The piezoresistive response of thin nanocomposite laminae has been assessed by measuring the variation of the electrical resistance as a function of the flexural strain in three-point bending tests under both quasi-static monotonic and dynamic cyclic loading conditions. The obtained results showed higher strain sensitivity than traditional metal foil strain gauges or recently investigated carbon-based nanocomposite films.

Method and system for making integrated solid-state fire-sets and detonators

DOEpatents

O`Brien, D.W.; Druce, R.L.; Johnson, G.W.; Vogtlin, G.E.; Barbee, T.W. Jr.; Lee, R.S.

1998-03-24

A slapper detonator comprises a solid-state high-voltage capacitor, a low-jitter dielectric breakdown switch and trigger circuitry, a detonator transmission line, an exploding foil bridge, and a flier material. All these components are fabricated in a single solid-state device using thin film deposition techniques. 13 figs.

Model and Subcomponent Development for a Pulse-Combustor-Driven Microgenerator

DTIC Science & Technology

2004-08-31

sputtering of thin magnetic and dielectric layers [4]; and mechanical lamination of polymer -coated NiFe foils [5]. Although these approaches have...photomicrograph of the fabricated device is given in Figure 4.2-6. 3d solenoid- like Cu coil EPOXY SU8 NIFE LAMINATE D CORE Figure 4.2-6 Photomicrograph

A microcalorimeter for measuring heat effects of electrochemical reactions with submonolayer conversions

NASA Astrophysics Data System (ADS)

Etzel, Kai D.; Bickel, Katrin R.; Schuster, Rolf

2010-03-01

We present a microcalorimeter for measuring heat effects during electrochemical reactions with conversions down to a few percent of a monolayer, referenced to the electrode's surface atoms. The design uses a thin pyroelectric polymer foil for temperature measurement at the backside of a thin electrode, similar to the concepts pioneered by the groups of D. A. King and Ch. T. Campbell for UHV adsorption microcalorimetry. To establish intimate thermal contact between electrode and sensor and utmost sensitivity, the free standing sensor and electrode foils are pressed together by air pressure, acting on the electrochemical cell. Pyroelectric temperature sensing is combined with pulsed electrochemistry, where the electrochemical heat is released on a time scale of about 10 ms, which is long enough for thermal equalization of the electrode-sensor assembly but short enough to avoid significant heat loss into electrolyte and cell compartment. As examples heat effects upon Ag deposition and dissolution as well as the electron transfer reaction of [Fe(CN)6]4-/[Fe(CN)6]3- are presented. The latter reaction was also employed for the calibration of the calorimeter.

Internal stress-assisted epitaxial lift-off process for flexible thin film (In)GaAs solar cells on metal foil

NASA Astrophysics Data System (ADS)

Kim, Youngjo; Kim, Kangho; Jung, Sang Hyun; Kim, Chang Zoo; Shin, Hyun-Beom; Choi, JeHyuk; Kang, Ho Kwan

2017-12-01

Flexible thin film (In)GaAs solar cells are grown by metalorganic chemical vapor deposition on GaAs substrates and transferred to 30 μm thick Au foil by internal stress-assisted epitaxial lift-off processes. The internal stress is induced by replacing the solar cell epi-layers from GaAs to In0.015Ga0.985As, which has a slightly larger lattice constant. The compressive strained layer thickness was varied from 0 to 4.5 μm to investigate the influence of the internal stress on the epitaxial lift-off time. The etching time in the epitaxial lift-off process was reduced from 36 to 4 h by employing a GaAs/In0.015Ga0.985As heterojunction structure that has a compressive film stress of -59.0 MPa. We found that the partially strained epi-structure contributed to the much faster lateral etching rate with spontaneous bending. Although an efficiency degradation problem occurred in the strained solar cell, it was solved by optimizing the epitaxial growth conditions.

Modelling the effects of the radiation reaction force on the interaction of thin foils with ultra-intense laser fields

NASA Astrophysics Data System (ADS)

Duff, M. J.; Capdessus, R.; Del Sorbo, D.; Ridgers, C. P.; King, M.; McKenna, P.

2018-06-01

The effects of the radiation reaction (RR) force on thin foils undergoing radiation pressure acceleration (RPA) are investigated. Using QED-particle-in-cell simulations, the influence of the RR force on the collective electron dynamics within the target can be examined. The magnitude of the RR force is found to be strongly dependent on the target thickness, leading to effects which can be observed on a macroscopic scale, such as changes to the distribution of the emitted radiation and the target dynamics. This suggests that such parameters may be controlled in experiments at multi-PW laser facilities. In addition, the effects of the RR force are characterized in terms of an average radiation emission angle. We present an analytical model which, for the first time, describes the effect of the RR force on the collective electron dynamics within the ‘light-sail’ regime of RPA. The predictions of this model can be tested in future experiments with ultra-high intensity lasers interacting with solid targets.

Soft X-ray Spectrometer for Characterization of Electron Beam Driven WDM

NASA Astrophysics Data System (ADS)

Ramey, Nicholas; Coleman, Joshua; Perry, John

2017-10-01

A preliminary design study is being performed on a soft X-ray spectrometer to measure K-shell spectra emitted by a warm dense plasma generated by an intense, relativistic electron beam interacting with a thin, low-Z metal foil. A 100-ns-long electron pulse with a beam current of 1.7 kA and energy of 19.8 MeV deposits energy into the thin metal foil heating it to a warm dense plasma. The collisional ionization of the target by the electron beam produces an anisotropic angular distribution of K-shell radiation and a continuum of both scattered electrons and Bremsstrahlung up to the beam energy of 19.8 MeV. A proof-of-principle Bragg-type spectrometer has been built to measure the Ti K- α and K- β lines. The goal of the spectrometer is to measure the temperature and density of this warm dense plasma for the first time with this heating technique. This work was supported by the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC52-06NA25396.

Gas Suppression via Copper Interlayers in Magnetron Sputtered Al-Cu2O Multilayers.

PubMed

Kinsey, Alex H; Slusarski, Kyle; Sosa, Steven; Weihs, Timothy P

2017-07-05

The use of thin-foil, self-propagating thermite reactions to bond components successfully depends on the ability to suppress gas generation and avoid pore formation during the exothermic production of brazes. To study the mechanisms of vapor production in diluted thermites, thin film multilayer Al-Cu-Cu 2 O-Cu foils are produced via magnetron sputtering, where the Cu layer thickness is systematically increased from 0 to 100 nm in 25 nm increments. The excess Cu layers act as diffusion barriers, limiting the transport of oxygen from the oxide to the Al fuel, as determined by slow heating differential scanning calorimetry experiments. Furthermore, by adding excess Cu to the system, the temperature of the self-propagating thermite reactions drops below the boiling point of Cu, eliminating the metal vapor production. It is determined that Cu vapor production can be eliminated by increasing the Cu interlayer thickness above 50 nm. However, the porous nature of the final products suggests that only metal vapor production is suppressed via dilution. Gas generation via oxygen release is still capable of producing a porous reaction product.

Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulthess, Jason

2014-09-01

Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

Technique for Configuring an Actively Cooled Thermal Shield in a Flight System

NASA Technical Reports Server (NTRS)

Barkfknecht, Peter; Mustafi, Shuvo

2011-01-01

Broad area cooling shields are a mass-efficient alternative to conductively cooled thermal radiation shielding. The shield would actively intercept a large portion of incident thermal radiation and transport the heat away using cryogenic helium gas. The design concept consists of a conductive and conformable surface that maximizes heat transfer and formability. Broad Area Cooled (BAC) shields could potentially provide considerable mass savings for spaceflight applications by eliminating the need for a rigid thermal radiation shield for cryogen tanks. The BAC consists of a network of capillary tubes that are thermally connected to a conductive shield material. Chilled helium gas is circulated through the network and transports unwanted heat away from the cryogen tanks. The cryogenic helium gas is pumped and chilled simultaneously using a specialized pulse-tube cryocooler, which further improves the mass efficiency of the system. By reducing the thermal environment temperature from 300 to 100 K, the radiative heat load on a cryogen tank could be reduced by an order of magnitude. For a cryogenic liquid propellant scenario of oxygen and hydrogen, the boiloff of hydrogen would be significantly reduced and completely eliminated for oxygen. A major challenge in implementing this technology on large tanks is that the BAC system must be easily scalable from lab demonstrations to full-scale missions. Also, the BAC shield must be conformable to complex shapes like spheres without losing the ability to maintain constant temperature throughout. The initial design maximizes thermal conductivity between the capillary tube and the conductive radiation shielding by using thin, corrugated aluminum foil with the tube running transverse to the folds. This configuration has the added benefit of enabling the foil to stretch and contract longitudinally. This allows the BAC to conform to the complex curvature of a cryogen tank, which is key to its success. To demonstrate a BAC shield system with minimal impact to current cryogen tank designs, the shielding must be applied after the final assembly of the tank and supporting structure. One method is to pre-fabricate the shield in long strips. A spool of corrugated aluminum foil with a thermally sunk aluminum capillary running through the center could then be simply wound around the cryogen tanks and encapsulated within the multi-layer insulation (MLI) blanket. Then, on orbit, the BAC would intercept thermal radiation coming in through the MLI and transport it away from the cryogen tanks. An optimization of the design could be done to take into account mass savings from thinner MLI blankets, eliminating solid thermal shields, and ultimately, a reduction in the required cryogen tank size.

Thin-film CdTe detector for microdosimetric study of radiation dose enhancement at gold-tissue interface.

PubMed

Paudel, Nava Raj; Shvydka, Diana; Parsai, E Ishmael

2016-09-08

Presence of interfaces between high and low atomic number (Z) materials, often encountered in diagnostic imaging and radiation therapy, leads to radiation dose perturbation. It is characterized by a very narrow region of sharp dose enhancement at the interface. A rapid falloff of dose enhancement over a very short distance from the interface makes the experimental dosimetry nontrivial. We use an in-house-built inexpensive thin-film Cadmium Telluride (CdTe) photodetector to study this effect at the gold-tissue interface and verify our experimental results with Monte Carlo (MC) modeling. Three-micron thick thin-film CdTe photodetectors were fabricated in our lab. One-, ten- or one hundred-micron thick gold foils placed in a tissue-equivalent-phantom were irradiated with a clinical Ir-192 high-dose-rate (HDR) source and current measured with a CdTe detector in each case was compared with the current measured for all uniform tissue-equivalent phantom. Percentage signal enhancement (PSE) due to each gold foil was then compared against MC modeled percentage dose enhancement (PDE), obtained from the geometry mimicking the experimental setup. The experimental PSEs due to 1, 10, and 100 μm thick gold foils at the closest measured distance of 12.5μm from the interface were 42.6 ± 10.8 , 137.0 ± 11.9, and 203.0 ± 15.4, respectively. The corresponding MC modeled PDEs were 38.1 ± 1, 164 ± 1, and 249 ± 1, respectively. The experimental and MC modeled values showed a closer agreement at the larger distances from the interface. The dose enhancement in the vicinity of gold-tissue interface was successfully measured using an in-house-built, high-resolution CdTe-based photodetector and validated with MC simulations. A close agreement between experimental and the MC modeled results shows that CdTe detector can be utilized for mapping interface dose distribution encountered in the application of ionizing radiation. © 2016 The Authors.

Conducting ion tracks generated by charge-selected swift heavy ions

NASA Astrophysics Data System (ADS)

Gupta, Srashti; Gehrke, H. G.; Krauser, J.; Trautmann, C.; Severin, D.; Bender, M.; Rothard, H.; Hofsäss, H.

2016-08-01

Conducting ion tracks in tetrahedral amorphous carbon (ta-C) thin films were generated by irradiation with swift heavy ions of well-defined charge state. The conductivity of tracks and the surface topography of the films, showing characteristic hillocks at each track position, were investigated using conductive atomic force microscopy measurements. The dependence of track conductivity and hillock size on the charge state of the ions was studied using 4.6 MeV/u Pb ions of charge state 53+, 56+ and 60+ provided by GANIL, as well as 4.8 MeV/u Bi and Au ions of charge state from 50+ to 61+ and 4.2 MeV/u 238U ions in equilibrium charge state provided by UNILAC of GSI. For the charge state selection at GSI, an additional stripper-foil system was installed at the M-branch that now allows routine irradiations with ions of selected charge states. The conductivity of tracks in ta-C increases significantly when the charge state increases from 51+ to 60+. However, the conductivity of individual tracks on the same sample still shows large variations, indicating that tracks formed in ta-C are either inhomogeneous or the conductivity is limited by the interface between ion track and Si substrate.

Development of damage suppression system using embedded SMA foil sensor and actuator

NASA Astrophysics Data System (ADS)

Ogisu, Toshimichi; Nomura, Masato; Ando, Norio; Takaki, Junji; Song, Dong Y.; Takeda, Nobuo

2000-06-01

The recent studies suggest possible applications of shape memory alloy (SMA) for a smart health monitoring and suppression of damage growth. The authors have been conducting research and development studies on applications of embedded SMA foil sensors and actuators in CFRP laminates. The goal of this research is suppression of damage growth in CFRP laminates. At first, the authors proposed a concept of damage suppression in CFRP laminates. Then, the development studies are conducted in three phases. The first phase is the improvement of interlaminar shear strength between SMA and CFRP laminates. Some surface treatments were investigated for the improvement of bonding property by peel resistance test and single lap shear strength test. The second phase is the investigation of fabrication technique for producing a CFRP panel with embedded SMA foils. Fixture jigs were devised to introduce tensile loads during the fabrication process. The third phase is the strength demonstration of CFRP laminates with embedded SMA foils. Some strength test were conducted to obtain the design data for aircraft structures. It is confirmed that the shrinking force of pre-strained SMA influences to the strength and the crack density of CFRP panel.

Multiple scattering of 13 and 20 MeV electrons by thin foils: a Monte Carlo study with GEANT, Geant4, and PENELOPE.

PubMed

Vilches, M; García-Pareja, S; Guerrero, R; Anguiano, M; Lallena, A M

2009-09-01

In this work, recent results from experiments and simulations (with EGSnrc) performed by Ross et al. [Med. Phys. 35, 4121-4131 (2008)] on electron scattering by foils of different materials and thicknesses are compared to those obtained using several Monte Carlo codes. Three codes have been used: GEANT (version 3.21), Geant4 (version 9.1, patch03), and PENELOPE (version 2006). In the case of PENELOPE, mixed and fully detailed simulations have been carried out. Transverse dose distributions in air have been obtained in order to compare with measurements. The detailed PENELOPE simulations show excellent agreement with experiment. The calculations performed with GEANT and PENELOPE (mixed) agree with experiment within 3% except for the Be foil. In the case of Geant4, the distributions are 5% narrower compared to the experimental ones, though the agreement is very good for the Be foil. Transverse dose distribution in water obtained with PENELOPE (mixed) is 4% wider than those calculated by Ross et al. using EGSnrc and is 1% narrower than the transverse dose distributions in air, as considered in the experiment. All the codes give a reasonable agreement (within 5%) with the experimental results for all the material and thicknesses studied.

Enhanced pair plasma generation in the relativistic transparency regime

NASA Astrophysics Data System (ADS)

Liu, W. Y.; Luo, W.; Yuan, T.; Yu, J. Y.; Chen, M.; Sheng, Z. M.

2017-10-01

Electron-positron ( e - e + ) pair plasma generation in the relativistic transparency regime in a thin foil with a fixed thickness irradiated by two counter-propagating laser pulses is investigated through multi-dimensional particle-in-cell simulations. It is shown that target transparency can significantly enhance the pair generation due to the formation of a stable standing wave. An optimum foil density of 200-280 n c (with nc being the critical plasma density of the incident laser at the wavelength of 1 μm) is found for enhanced e - e + pair generation for laser intensity around 10 PW. With such foil density, laser energy transformed to pair plasma formation is approximately four times higher than that with a foil density of 710 nc, while the laser energy transformed to γ-photons remains almost the same. Dense e - e + plasma with a density as high as 10 22 cm - 3 ( ≃ 10 n c ) can be produced accordingly. Comparison of pair plasma generation between cases with fundamental and double frequency driver lasers further demonstrates such an enhancement effect. It shows that when the duration of the laser pulse is relatively short, the double frequency driver can generate more pair plasmas due to the earlier excitation of relativistic transparency.

Final Report: Posttest Analysis of Omega II Optical Specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newlander, C D; Fisher, J H

Preliminary posttest analyses have been completed on optical specimens exposed during the Omega II test series conducted on 14 July 2006. The Omega Facility, located at the Laboratory for Laser Energetics (LLE) at the University of Rochester was used to produce X-ray environments through the interaction of intense pulsed laser radiation upon germanium-loaded silica aerogels. The optical specimen testing was supported by GH Systems through experiment design, pre- and post-test analyses, specimen acquisition, and overall technical experience. The test specimens were fabricated and characterized by Surface Optics Corporation (SOC), San Diego, CA and were simple protected gold coatings on silicamore » substrates. Six test specimens were exposed, five filtered with thin beryllium foil filters, and one unfiltered which was exposed directly to the raw environment. The experimental objectives were: (1) demonstrate that tests of optical specimens could be performed at the Omega facility; (2) evaluate the use and survivability of beryllium foil filters as a function of thickness; (3) obtain damage data on optical specimens which ranged from no damage to damage; (4) correlate existing thermal response models with the damage data; (5) evaluate the use of the direct raw environment upon the specimen response and the ability/desirability to conduct sensitive optical specimen tests using the raw environment; and (6) initiate the development of a protocol for performing optical coatings/mirror tests. This report documents the activities performed by GH Systems in evaluating and using the environments provided by LLNL, the PUFFTFT analyses performed using those environments, and the calculated results compared to the observed and measured posttest data.« less

"Silicon millefeuille": From a silicon wafer to multiple thin crystalline films in a single step

NASA Astrophysics Data System (ADS)

Hernández, David; Trifonov, Trifon; Garín, Moisés; Alcubilla, Ramon

2013-04-01

During the last years, many techniques have been developed to obtain thin crystalline films from commercial silicon ingots. Large market applications are foreseen in the photovoltaic field, where important cost reductions are predicted, and also in advanced microelectronics technologies as three-dimensional integration, system on foil, or silicon interposers [Dross et al., Prog. Photovoltaics 20, 770-784 (2012); R. Brendel, Thin Film Crystalline Silicon Solar Cells (Wiley-VCH, Weinheim, Germany 2003); J. N. Burghartz, Ultra-Thin Chip Technology and Applications (Springer Science + Business Media, NY, USA, 2010)]. Existing methods produce "one at a time" silicon layers, once one thin film is obtained, the complete process is repeated to obtain the next layer. Here, we describe a technology that, from a single crystalline silicon wafer, produces a large number of crystalline films with controlled thickness in a single technological step.

Recompressed exfoliated graphite articles

DOEpatents

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

2013-08-06

This invention provides an electrically conductive, less anisotropic, recompressed exfoliated graphite article comprising a mixture of (a) expanded or exfoliated graphite flakes; and (b) particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and about 70% by weight based on the total weight of the particles and the expanded graphite flakes combined; wherein the mixture is compressed to form the article having an apparent bulk density of from about 0.1 g/cm.sup.3 to about 2.0 g/cm.sup.3. The article exhibits a thickness-direction conductivity typically greater than 50 S/cm, more typically greater than 100 S/cm, and most typically greater than 200 S/cm. The article, when used in a thin foil or sheet form, can be a useful component in a sheet molding compound plate used as a fuel cell separator or flow field plate. The article may also be used as a current collector for a battery, supercapacitor, or any other electrochemical cell.

An Innovative Method for Manufacturing Gamma-TiAl Foil

NASA Technical Reports Server (NTRS)

Hales, Stephen J.; Saqib, Mohammad; Alexa, Joel A.

2003-01-01

The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by the inherent low room temperature ductility of the material. In the present study a new approach was explored for the efficient manufacture of gamma-TiAl foil with improved ductility. The objective was to produce a very clean material (low interstitial content) with a highly refined, homogeneous microstructure placed in a fully lamellar condition. The processing route involved the use of RF plasma spray deposition of pre-alloyed powders, followed by consolidation via vacuum hot pressing and heat treatment. The approach took advantage of a deposition process which included no electrodes, no binders and high cooling rates. Results and discussion of the work performed to date are presented.

Highly stretchable miniature strain sensor for large dynamic strain measurement

DOE PAGES

Song, Bo; Yao, Shurong; Nie, Xu; ...

2016-01-01

In this paper, a new type of highly stretchable strain sensor was developed to measure large strains. The sensor was based on the piezo-resistive response of carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite thin films. The piezo-resistive response of CNT composite gives accurate strain measurement with high frequency response, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measurement. Experimental results show that the CNT/PDMS sensor measures large strains (up to 8 %) with an excellent linearity and a fast frequency response. The new miniature strain sensor also exhibits much higher sensitivities than the conventional foil strain gages,more » as its gauge factor is 500 times of that of the conventional foil strain gages.« less

Thermal Sensitive Foils in Physics Experiments

ERIC Educational Resources Information Center

Bochnícek, Zdenek; Konecný, Pavel

2014-01-01

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Validation of the ENSCO surrogate bogie vehicle, FOIL test numbers 92F028 through 92F031

DOT National Transportation Integrated Search

1994-11-01

This document contains the results from four crash tests conducted at the Federal Outdoor Impact Laboratory (FOIL) located at the Turner-Fairbank Highway Research Center in McLean, Virginia. The crash tests involved two reusable bogie vehicles impact...

Eddy current probe with foil sensor mounted on flexible probe tip and method of use

DOEpatents

Viertl, John R. M.; Lee, Martin K.

2001-01-01

A pair of copper coils are embedded in the foil strip. A first coil of the pair generates an electromagnetic field that induces eddy currents on the surface, and the second coil carries a current influenced by the eddy currents on the surface. The currents in the second coil are analyzed to obtain information on the surface eddy currents. An eddy current probe has a metal housing having a tip that is covered by a flexible conductive foil strip. The foil strip is mounted on a deformable nose at the probe tip so that the strip and coils will conform to the surface to which they are applied.

All-inorganic large-area low-cost and durable flexible perovskite solar cells using copper foil as a substrate.

PubMed

Abdollahi Nejand, B; Nazari, P; Gharibzadeh, S; Ahmadi, V; Moshaii, A

2017-01-05

Here, a low-cost perovskite solar cell using CuI and ZnO as the respective inorganic hole and electron transport layers is introduced. Copper foil is chosen as a cheap and low-weight conductive substrate which has a similar work function to ITO. Besides, copper foil is an interesting copper atom source for the growth of the upper cuprous iodide layer on copper foil. A spray coating of a transparent silver nanowire electrode is used as a top contact. The prepared device shows a maximum power conversion efficiency of 12.80% and long-term durability providing an environmentally and market friendly perovskite solar cell.

An electron-microscope study of alpha to gamma transformation in an iron-nickel alloy

NASA Technical Reports Server (NTRS)

Lobodyuk, V. A.; Khandros, L. G.; Fedas, N. P.

1980-01-01

Procedures used to study the alpha to gamma conversion in thin foils of an iron alloy with 32% nickel concentration and initial martensite conversion temperature of -60 C are described. Photomicrographs show deformation twinning as well as changes in samples after they were heated. Reverse conversion is discussed and results are examined.

IMM Solar Cell Shows Its Versatility - Continuum Magazine | NREL

Science.gov Websites

. Inventing a new type of solar cell is one thing. Setting efficiency records with it and winning major awards add to the achievement. But when one of the world's leading manufacturers of compound semiconductor thin metal foil, and the substrate that the cell was grown on is removed. One advantage of this

Alternative designs for space x-ray telescopes

NASA Astrophysics Data System (ADS)

Hudec, R.; Pína, L.; Maršíková, Veronika; Černá, Daniela; Inneman, A.; Tichý, V.

2017-11-01

The X-ray optics is a key element of space X-ray telescopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All related space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non-Wolter X-ray optics designs for the future. The alternative designs require novel reflective substrates which are also discussed in the paper.

An integration machine for the assembly of the x-ray optic units based on thin slumped glass foils for the IXO mission

NASA Astrophysics Data System (ADS)

Civitani, M. M.; Basso, S.; Bavdaz, M.; Citterio, O.; Conconi, P.; Gallieni, D.; Ghigo, M.; Martelli, F.; Pareschi, G.; Parodi, G.; Proserpio, L.; Sironi, G.; Spiga, D.; Tagliaferri, G.; Tintori, M.; Wille, E.; Zambra, A.

2011-09-01

The International X-ray Observatory (IXO) is a joint mission concept studied by the ESA, NASA, and JAXA space agencies. The main goal of the mission design is to achieve a large effective area (>2.5m2 at 1 keV) and a good angular resolution (5 arcsec HEW at 1 keV) at the same time. The Brera Astronomical Observatory - INAF, Italy), under the support of ESA, is developing a method for the realization of the X-Ray Optical Units, based on the use of slumped thin glass segments to form densely packed modules in a Wolter type I optical configuration. In order to reach the very challenging integration requirements, it has been developed an innovative assembly approach for aligning and mounting the IXO mirror segments. The method is based on the use of an integration mould for each foil. In particular the glass segment is forced to adhere to the integration mould in order to maintain the optimal figure without deformations until the integration of the foil in the stack is completed. In this way an active correction for major existing figure errors after slumping is also achieved. Moreover reinforcing ribs are used in order to connect the facets to each-other and to realize a robust monolithic stack of plates. In this paper we present the design, the development and the validation status of a special Integration Machine (IMA) that has been specifically developed to allow the integration of the Plate Pairs into prototypal X-Ray Optical Unit stacks.

Simulated Thin-Film Growth and Imaging

NASA Astrophysics Data System (ADS)

Schillaci, Michael

2001-06-01

Thin-films have become the cornerstone of the electronics, telecommunications, and broadband markets. A list of potential products includes: computer boards and chips, satellites, cell phones, fuel cells, superconductors, flat panel displays, optical waveguides, building and automotive windows, food and beverage plastic containers, metal foils, pipe plating, vision ware, manufacturing equipment and turbine engines. For all of these reasons a basic understanding of the physical processes involved in both growing and imaging thin-films can provide a wonderful research project for advanced undergraduate and first-year graduate students. After producing rudimentary two- and three-dimensional thin-film models incorporating ballsitic deposition and nearest neighbor Coulomb-type interactions, the QM tunneling equations are used to produce simulated scanning tunneling microscope (SSTM) images of the films. A discussion of computational platforms, languages, and software packages that may be used to accomplish similar results is also given.

Unitary plate electrode

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor); Clough, Thomas J. (Inventor); Josefowicz, Jack Y. (Inventor); Sibert, John W. (Inventor)

1985-01-01

The unitary electrode (10) comprises a porous sheet (12) of fiberglass the strands (14) of which contain a coating (16) of conductive tin oxide. The lower portion of the sheet contains a layer (18) of resin and the upper layer (20) contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands (14) form a continuous conduction path through both layers (16, 18). Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film (130) of lead or graphite filled resin adhered to the plate with a layer (31) of conductive adhesive. The plate (10) can be formed by casting a molten resin from kettle (60) onto a sheet of glass wool (56) overlying a sheet of lead foil and then applying positive active paste from hopper (64) into the upper layer (68). The plate can also be formed by passing an assembly of a sheet ( 80) of resin, a sheet (86) of sintered glass and a sheet (90) of lead between the nip (92) of heated rollers (93, 95) and then filling lead oxide into the pores (116) of the upper layer (118).

Atmospheric Pressure Plasma Jet as a Dry Alternative to Inkjet Printing in Flexible Electronics

NASA Technical Reports Server (NTRS)

Gandhiraman, Ram Prasad; Lopez, Arlene; Koehne, Jessica; Meyyappan, M.

2016-01-01

We have developed an atmospheric pressure plasma jet printing system that works at room temperature to 50 deg C unlike conventional aerosol assisted techniques which require a high temperature sintering step to obtain desired thin films. Multiple jets can be configured to increase throughput or to deposit multiple materials, and the jet(s) can be moved across large areas using a x-y stage. The plasma jet has been used to deposit carbon nanotubes, graphene, silver nanowires, copper nanoparticles and other materials on substrates such as paper, cotton, plastic and thin metal foils.

Reduction of angular divergence of laser-driven ion beams during their acceleration and transport

NASA Astrophysics Data System (ADS)

Zakova, M.; Pšikal, Jan; Margarone, Daniele; Maggiore, Mario; Korn, G.

2015-05-01

Laser plasma physics is a field of big interest because of its implications in basic science, fast ignition, medicine (i.e. hadrontherapy), astrophysics, material science, particle acceleration etc. 100-MeV class protons accelerated from the interaction of a short laser pulse with a thin target have been demonstrated. With continuing development of laser technology, greater and greater energies are expected, therefore projects focusing on various applications are being formed, e.g. ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration). One of the main characteristic and crucial disadvantage of ion beams accelerated by ultra-short intense laser pulses is their large divergence, not suitable for the most of applications. In this paper two ways how to decrease beam divergence are proposed. Firstly, impact of different design of targets on beam divergence is studied by using 2D Particlein-cell simulations (PIC). Namely, various types of targets include at foils, curved foil and foils with diverse microstructures. Obtained results show that well-designed microstructures, i.e. a hole in the center of the target, can produce proton beam with the lowest divergence. Moreover, the particle beam accelerated from a curved foil has lower divergence compared to the beam from a flat foil. Secondly, another proposed method for the divergence reduction is using of a magnetic solenoid. The trajectories of the laser accelerated particles passing through the solenoid are modeled in a simple Matlab program. Results from PIC simulations are used as input in the program. The divergence is controlled by optimizing the magnetic field inside the solenoid and installing an aperture in front of the device.

Shock Wave Based Biolistic Device for DNA and Drug Delivery

NASA Astrophysics Data System (ADS)

Nakada, Mutsumi; Menezes, Viren; Kanno, Akira; Hosseini, S. Hamid R.; Takayama, Kazuyoshi

2008-03-01

A shock wave assisted biolistic (biological ballistic) device has been developed to deliver DNA/drug-coated micro-projectiles into soft living targets. The device consists of an Nd:YAG laser, an optical setup to focus the laser beam and, a thin aluminum (Al) foil (typically 100 µm thick) which is a launch pad for the micro-projectiles. The DNA/drug-coated micro-particles to be delivered are deposited on the anterior surface of the foil and the posterior surface of the foil is ablated using the laser beam with an energy density of about 32×109 W/cm2. The ablation launches a shock wave through the foil that imparts an impulse to the foil surface, due to which the deposited particles accelerate and acquire sufficient momentum to penetrate soft targets. The device has been tested for particle delivery by delivering 1 µm size tungsten particles into liver tissues of experimental rats and in vitro test models made of gelatin. The penetration depths of about 90 and 800 µm have been observed in the liver and gelatin targets, respectively. The device has been tested for in vivo DNA [encoding β-glucuronidase (GUS) gene] transfer by delivering plasmid DNA-coated, 1-µm size gold (Au) particles into onion scale, tobacco leaf and soybean seed cells. The GUS activity was detected in the onion, tobacco and soybean cells after the DNA delivery. The present device is totally non-intrusive in nature and has a potential to get miniaturized to suit the existing medical procedures for DNA and/or drug delivery.

SMA Foils for MEMS: From Material Properties to the Engineering of Microdevices

NASA Astrophysics Data System (ADS)

Kohl, Manfred; Ossmer, Hinnerk; Gueltig, Marcel; Megnin, Christof

2018-03-01

In the early nineties, microelectromechanical systems (MEMS) technology has been still in its infancy. As silicon (Si) is not a transducer material, it was clear at the very beginning that mechanically active materials had to be introduced to MEMS in order to enable functional microdevices with actuation capability beyond electrostatics. At that time, shape memory alloys (SMAs) have been available in bulk form, mainly as SMA wires and SMA plates. On the macro scale, these materials show highest work densities compared to other actuation principles in the order of 107 J/m3, which stimulated research on the integration of SMA to MEMS. Subsequently, two approaches for producing planar materials have been initiated (1) magnetron sputtering of SMA thin films and (2) the integration of rolled SMA foils, which both turned out to be very successful creating a paradigm change in microactuation technology. The following review covers important milestones of the research and development of SMA foil-based microactuators including materials characterization, design engineering, technology, and demonstrator development as well as first commercial products.

Measuring Submicron-Sized Fractionated Particulate Matter on Aluminum Impactor Disks

PubMed Central

Buchholz, Bruce A.; Zermeño, Paula; Hwang, Hyun-Min; Young, Thomas M.; Guilderson, Thomas P.

2011-01-01

Sub-micron sized airborne particulate matter (PM) is not collected well on regular quartz or glass fiber filter papers. We used a micro-orifice uniform deposit impactor (MOUDI) to fractionate PM into six size fractions and deposit it on specially designed high purity thin aluminum disks. The MOUDI separated PM into fractions 56–100 nm, 100–180 nm, 180–320 nm, 320–560 nm, 560–1000 nm, and 1000–1800 nm. Since the MOUDI has a low flow rate (30 L/min), it takes several days to collect sufficient carbon on 47 mm foil disks. The small carbon mass (20–200 microgram C) and large aluminum substrate (~25 mg Al) present several challenges to production of graphite targets for accelerator mass spectrometry (AMS) analysis. The Al foil consumes large amounts of oxygen as it is heated and tends to melt into quartz combustion tubes, causing gas leaks. We describe sample processing techniques to reliably produce graphitic targets for 14C-AMS analysis of PM deposited on Al impact foils. PMID:22228915

SMA Foils for MEMS: From Material Properties to the Engineering of Microdevices

NASA Astrophysics Data System (ADS)

Kohl, Manfred; Ossmer, Hinnerk; Gueltig, Marcel; Megnin, Christof

2017-12-01

In the early nineties, microelectromechanical systems (MEMS) technology has been still in its infancy. As silicon (Si) is not a transducer material, it was clear at the very beginning that mechanically active materials had to be introduced to MEMS in order to enable functional microdevices with actuation capability beyond electrostatics. At that time, shape memory alloys (SMAs) have been available in bulk form, mainly as SMA wires and SMA plates. On the macro scale, these materials show highest work densities compared to other actuation principles in the order of 107 J/m3, which stimulated research on the integration of SMA to MEMS. Subsequently, two approaches for producing planar materials have been initiated (1) magnetron sputtering of SMA thin films and (2) the integration of rolled SMA foils, which both turned out to be very successful creating a paradigm change in microactuation technology. The following review covers important milestones of the research and development of SMA foil-based microactuators including materials characterization, design engineering, technology, and demonstrator development as well as first commercial products.

Maintaining stable radiation pressure acceleration of ion beams via cascaded electron replenishment

NASA Astrophysics Data System (ADS)

Shen, X. F.; Qiao, B.; Chang, H. X.; Zhang, W. L.; Zhang, H.; Zhou, C. T.; He, X. T.

2017-03-01

A method to maintain ion stable radiation pressure acceleration (RPA) from laser-irradiated thin foils is proposed, where a series of high-Z nanofilms are placed behind to successively replenish co-moving electrons into the accelerating foil as electron charging stations (ECSs). Such replenishment of co-moving electrons, on the one hand, helps to keep a dynamic balance between the electrostatic pressure in the accelerating slab and the increasing laser radiation pressure with a Gaussian temporal profile at the rising front, i.e. dynamically matching the optimal condition of RPA; on the other hand, it aids in suppressing the foil Coulomb explosion due to loss of electrons induced by transverse instabilities during RPA. Two-dimensional and three-dimensional particle-in-cell simulations show that a monoenergetic Si14+ beam with a peak energy of 3.7 GeV and particle number 4.8× {10}9 (charge 11 nC) can be obtained at an intensity of 7 × 1021 W cm-2 and the conversion efficiency from laser to high energy ions is improved significantly by using the ECSs in our scheme.

General solution growth of mesoporous NiCo2O4 nanosheets on various conductive substrates as high-performance electrodes for supercapacitors.

PubMed

Zhang, Genqiang; Lou, Xiong Wen David

2013-02-20

Mesoporous NiCo(2) O(4) nanosheets can be directly grown on various conductive substrates, such as Ni foam, Ti foil, stainless-steel foil and flexible graphite paper, through a general template-free solution method combined with a simple post annealing treatment. As a highly integrated binder- and conductive-agent-free electrode for supercapacitors, the mesoporous NiCo(2) O(4) nanosheets supported on Ni foam deliver ultrahigh capacitance and excellent high-rate cycling stability. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TERS v2.0: An improved version of TERS

NASA Astrophysics Data System (ADS)

Nath, S.

2009-11-01

We present a new version of the semimicroscopic Monte Carlo code "TERS". The procedure for calculating multiple small angle Coulomb scattering of the residues in the target has been modified. Target-backing and residue charge-reset foils, which are often used in heavy ion-induced complete fusion reactions, are included in the code. New version program summaryProgram title: TERS v2.0 Catalogue identifier: AEBD_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBD_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 7309 No. of bytes in distributed program, including test data, etc.: 1 219 555 Distribution format: tar.gz Programming language: C Computer: The code has been developed and tested on a PC with Intel Pentium IV processor. Operating system: Linux RAM: About 8 Mbytes Classification: 17.7 External routines: pgplot graphics subroutine library [1] should be installed in the system for generating residue trajectory plots. (The library is included in the CPC distribution file.) Catalogue identifier of previous version: AEBD_v1_0 Journal reference of previous version: Comput. Phys. Comm. 179 (2008) 492 Does the new version supersede the previous version?: Yes Nature of problem: Recoil separators are employed to select and identify nuclei of interest, produced in a nuclear reaction, rejecting unreacted beam and other undesired reaction products. It is important to know what fraction of the selected nuclei, leaving the target, reach the detection system. This information is crucial for determining absolute cross section of the studied reaction. Solution method: Interaction of projectiles with target nuclei is treated event by event, semimicro-scopically. Position and angle (with respect to beam direction), energy and charge state of the reaction products are calculated by Monte Carlo method. Trajectory of each nuclei inside the separator is then calculated by ion optical transfer matrix method. Ratio of the number of trajectories completing their journey up to the detection system to the total number of trajectories is a direct measure of absolute transmission efficiency of the separator. Reasons for new version: The method for calculating mean squared scattering angle (< ϑ > 2), used earlier [2], was found to be inadequate particularly for low energy heavy residues. Energy loss of beam in the target-backing foil and energy loss of residues in the charge-reset foil (wherever used) needed to be taken into account for better matching of simulated residue parameters with measurements. Summary of revisions: A new method [3] for calculating multiple small angle Coulomb scattering of residues in the target has been adopted. The change is incorporated in function Weibull() in the program ters_pti2.c. Isotopically enriched targets are made on a thin backing foil (usually made of carbon) quite often. Energy loss of beam in the backing foil (assuming beam is made to pass through the backing foil first, which is the usual practice) need to be taken into account. This calls for minor changes in the input file ters_pti2.inp. Following is the modified list of input parameters in this file with explanation. Atomic no. and mass no. of projectile and target. Projectile energy [MeV] in laboratory. Dia. [mm] of (circular) beam spot and target thickness [mg/cm2]. Atomic no. and mass no. of the backing material and thickness [mg/cm2] of the backing foil. Q value [MeV] for CN formation and inverse level density parameter. Numbers of evaporated alphas, protons and neutrons. Alpha separation energies [MeV], to be left blank if no alpha evaporation. Proton separation energies [MeV], to be left blank if no proton evaporation. Neutron separation energies [MeV], to be left blank if no neutron evaporation. Number of events i.e. residues to be considered by the program (maximum 5 ×105). The parameters in input line number 4 are new in this version. If the target is backed by a carbon foil of thickness 125 μg/cm2, the input line would look like "6 12 0.125". If the target is self-supporting, i.e. there is no backing, value of the last parameter (thickness) should be zero. However, the first two parameters must not be left blank or have 0 values. The input line would look like "6 12 0.0" in this case. A new function ThinFoil() has been introduced in the program ters_tra2.c. A thin foil can be inserted anywhere along the path of the residues by calling this function using the following syntax: Status = ThinFoil(argument list); if (Status == 0) continue; The function is particularly useful to place a residue charge-reset foil (usually made of carbon) after the target and is described in Table 1.Name of the functionJob of the functionList of argumentsDescription of argumentsThinFoil()To calculate ion energy loss in a thin foilint arg1, int arg2, int arg3arg1 = atomic number of the foil material, arg2 = mass number of the foil material, arg3 = thickness of the foil [mg/cm2] There is a minor change in the input file ters_tra2.inp. Following is the modified list of input parameters in this file with explanation. Residue atomic number and mass number. Energy [MeV], mass no. and charge state of the reference particle. Number of events i.e. trajectories to be calculated. Program/input files which have been modified in this version are suffixed by "2" in their names (before the extension), e.g., ters_pti.c has been renamed ters_pti2.c. The complete list of files included in the distributed code can be viewed in the readme file. Restrictions: The present version of the code is applicable to complete fusion reactions only. Calculation of transmission efficiency has been illustrated with a specific recoil separator, viz. the Heavy Ion Reaction Analyzer (HIRA) [4,5], at IUAC. One has to make necessary changes in the code, while performing calculations for other recoil separators. Also, atomic number of the residual nucleus should not exceed 92, as the method used for calculating stopping power of ions [6] is valid for Z ⩽ 92. The code can perform energy loss calculation only in elemental targets and foils (i.e. compounds or alloys are not supported). Further, number of events (NEVENT) in ters_tra2.inp should not exceed the same in ters_pti2.inp. Running time: From few seconds to several minutes depending on the reaction, number of events and separator layout. References: [1] http://www.astro.caltech.edu/~tjp/pgplot/. [2] G.R. Lynch, O.I. Dahl, Nucl. Instr. Methods B 58 (1991) 6. [3] L. Meyer, Phys. Status Solidi 44 (1971) 253. [4] A.K. Sinha, N. Madhavan, J.J. Das, P. Sugathan, D.O. Kataria, A.P. Patro, G.K. Mehta, Nucl. Instr. Methods A 339 (1994) 543. [5] S. Nath, Nucl. Instr. Methods A 576 (2007) 403. [6] J.F. Ziegler, J.P. Biersack, U. Littmark, The Stopping and Range of Ions in Solids, vol. I, Pergamon Press, Oxford, 1984.

Thermal contact resistance measurement of conduction cooled binary current lead joint block in cryocooler based self field I-V characterization facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kundu, Ananya, E-mail: ananya@ipr.res.in; Das, Subrat Kumar; Agarwal, Anees Bano Pooja

2016-05-23

In the present study thermal resistance of conduction cooled current lead joint block employing two different interfacial material namely AlN sheet and Kapton Film have been studied in the temperature range 5K-35K. In each case, the performance of different interlayer materials e.g. Indium foil for moderately pressurized contacts (contact pressure <1 MPa), and Apiezon N Grease, GE varnish for low pressurized contact (contact pressure <1 MPa) is studied. The performances of AlN joint with Indium foil and with Apeizon N Grease are studied and it is observed that the contact resistance reduces more with indium foil as compared to greasedmore » contact. The contact resistance measurements of Kapton film with Apiezon N grease and with GE varnish were also carried out in the same temperature range. A comparative study of AlN joint with Indium foil and Kapton with GE varnish as filler material is carried out to demonstrate better candidate material among Kapton and AlN for a particular filler material in the same temperature range.« less

Film/Adhesive Processing Module for Fiber-Placement Processing of Composites

NASA Technical Reports Server (NTRS)

Hulcher, A. Bruce

2007-01-01

An automated apparatus has been designed and constructed that enables the automated lay-up of composite structures incorporating films, foils, and adhesives during the automated fiber-placement process. This apparatus, denoted a film module, could be used to deposit materials in film or thin sheet form either simultaneously when laying down the fiber composite article or in an independent step.

An efficient and cost-effective method for preparing transmission electron microscopy samples from powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wen, Haiming; Lin, Yaojun; Seidman, David N.

The preparation of transmission electron microcopy (TEM) samples from powders with particle sizes larger than ~100 nm poses a challenge. The existing methods are complicated and expensive, or have a low probability of success. Herein, we report a modified methodology for preparation of TEM samples from powders, which is efficient, cost-effective, and easy to perform. This method involves mixing powders with an epoxy on a piece of weighing paper, curing the powder–epoxy mixture to form a bulk material, grinding the bulk to obtain a thin foil, punching TEM discs from the foil, dimpling the discs, and ion milling the dimpledmore » discs to electron transparency. Compared with the well established and robust grinding–dimpling–ion-milling method for TEM sample preparation for bulk materials, our modified approach for preparing TEM samples from powders only requires two additional simple steps. In this article, step-by-step procedures for our methodology are described in detail, and important strategies to ensure success are elucidated. Furthermore, our methodology has been applied successfully for preparing TEM samples with large thin areas and high quality for many different mechanically milled metallic powders.« less

A novel method for computing effective diffusivity: Application to helium implanted α-Fe thin films

NASA Astrophysics Data System (ADS)

Dunn, Aaron; Agudo-Merida, Laura; Martin-Bragado, Ignacio; McPhie, Mathieu; Cherkaoui, Mohammed; Capolungo, Laurent

2014-05-01

The effective diffusivity of helium in thin iron films is quantified using spatially resolved stochastic cluster dynamics and object kinetic Monte Carlo simulations. The roles of total displacement dose (in DPA), damage rate, helium to DPA ratio, layer thickness, and damage type (cascade damage vs Frenkel pair implantation) on effective He diffusivity are investigated. Helium diffusivity is found to decrease with increasing total damage and decreasing damage rate. Arrhenius plots show strongly increased helium diffusivity at high temperatures, high total implantation, and low implantation rates due to decreased vacancy and vacancy cluster concentrations. At low temperatures, effective diffusivity is weakly dependent on foil thickness while at high temperatures, narrower foils prevent defect accumulation by releasing all defects at the free surfaces. Helium to DPA ratio is not shown to strongly change helium diffusivity in the range of irradiation conditions simulated. Frenkel pair implantation is shown to cause higher effective diffusivity and more complex diffusion mechanisms than cascade implantation. The results of these simulations indicate that the differences in damage rates between implantation experiments and fission or fusion environments may result in differences in the final microstructure.

An efficient and cost-effective method for preparing transmission electron microscopy samples from powders

DOE PAGES

Wen, Haiming; Lin, Yaojun; Seidman, David N.; ...

2015-09-09

The preparation of transmission electron microcopy (TEM) samples from powders with particle sizes larger than ~100 nm poses a challenge. The existing methods are complicated and expensive, or have a low probability of success. Herein, we report a modified methodology for preparation of TEM samples from powders, which is efficient, cost-effective, and easy to perform. This method involves mixing powders with an epoxy on a piece of weighing paper, curing the powder–epoxy mixture to form a bulk material, grinding the bulk to obtain a thin foil, punching TEM discs from the foil, dimpling the discs, and ion milling the dimpledmore » discs to electron transparency. Compared with the well established and robust grinding–dimpling–ion-milling method for TEM sample preparation for bulk materials, our modified approach for preparing TEM samples from powders only requires two additional simple steps. In this article, step-by-step procedures for our methodology are described in detail, and important strategies to ensure success are elucidated. Furthermore, our methodology has been applied successfully for preparing TEM samples with large thin areas and high quality for many different mechanically milled metallic powders.« less

Prediction and characterization of heat-affected zone formation in tin-bismuth alloys due to nickel-aluminum multilayer foil reaction

DOE PAGES

Hooper, R. J.; Davis, C. G.; Johns, P. M.; ...

2015-06-26

Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. In this study, most of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To improve the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical modelmore » for the purpose of predicting heat affected zone size in substrate materials. The model is experimentally validated using a commercially available Ni-Al multilayer foils and alloys from the Sn-Bi binary system. To accomplish this, phenomenological models for predicting the variation of physical properties (i.e., thermal conductivity, density, and heat capacity) with temperature and composition in the Sn-Bi system were utilized using literature data.« less

New trends in space x-ray optics

NASA Astrophysics Data System (ADS)

Hudec, R.; Maršíková, V.; Pína, L.; Inneman, A.; Skulinová, M.

2017-11-01

The X-ray optics is a key element of various X-ray telescopes, X-ray microscopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non- Wolter X-ray optics designs for the future. Future large space X-ray telescopes (such as IXO) require precise and light-weight X-ray optics based on numerous thin reflecting shells. Novel approaches and advanced technologies are to be exploited and developed. In this contribution, we refer on results of tested X-ray mirror shells produced by glass thermal forming (GTF) and by shaping Si wafers. Both glass foils and Si wafers are commercially available, have excellent surface microroughness of a few 0.1 nm, and low weight (the volume density is 2.5 g cm-3 for glass and 2.3 g cm-3 for Si). Technologies are needed to be exploited; how to shape these substrates to achieve the required precise Xray optics geometries without degradations of the fine surface microroughness. Although glass and recently silicon wafers are considered to represent most promising materials for future advanced large aperture space Xray telescopes, there also exist other alternative materials worth further study such as amorphous metals and glassy carbon [1]. In order to achieve sub-arsec angular resolutions, principles of active optics have to be adopted.

Diagnosis of warm dense conditions in foil targets heated by intense femtosecond laser pulses using Kα imaging spectroscopy

DOE PAGES

Bae, L. J.; Zastrau, U.; Chung, H. -K.; ...

2018-03-01

Warm dense conditions in titanium foils irradiated with intense femtosecond laser pulses are diagnosed using an x-ray imaging spectroscopy technique. The line shapes of radially resolved titanium Kα spectra are measured with a toroidally bent GaAs crystal and an x-ray charge-coupled device. Measured spectra are compared with the K-shell emissions modeled using an atomic kinetics – spectroscopy simulation code. Kα line shapes are strongly affected by warm (5-40 eV) bulk electron temperatures and imply multiple temperature distributions in the targets. Finally, the spatial distribution of temperature is dependent on the target thickness, and a thin target shows an advantage tomore » generate uniform warm dense conditions in a large area.« less

Multiple layer insulation cover

DOEpatents

Farrell, James J.; Donohoe, Anthony J.

1981-11-03

A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

Synthesis of atomically thin hexagonal boron nitride films on nickel foils by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Nakhaie, S.; Wofford, J. M.; Schumann, T.; Jahn, U.; Ramsteiner, M.; Hanke, M.; Lopes, J. M. J.; Riechert, H.

2015-05-01

Hexagonal boron nitride (h-BN) is a layered two-dimensional material with properties that make it promising as a dielectric in various applications. We report the growth of h-BN films on Ni foils from elemental B and N using molecular beam epitaxy. The presence of crystalline h-BN over the entire substrate is confirmed by Raman spectroscopy. Atomic force microscopy is used to examine the morphology and continuity of the synthesized films. A scanning electron microscopy study of films obtained using shorter depositions offers insight into the nucleation and growth behavior of h-BN on the Ni substrate. The morphology of h-BN was found to evolve from dendritic, star-shaped islands to larger, smooth triangular ones with increasing growth temperature.

Diagnosis of warm dense conditions in foil targets heated by intense femtosecond laser pulses using Kα imaging spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, L. J.; Zastrau, U.; Chung, H. -K.

Warm dense conditions in titanium foils irradiated with intense femtosecond laser pulses are diagnosed using an x-ray imaging spectroscopy technique. The line shapes of radially resolved titanium Kα spectra are measured with a toroidally bent GaAs crystal and an x-ray charge-coupled device. Measured spectra are compared with the K-shell emissions modeled using an atomic kinetics – spectroscopy simulation code. Kα line shapes are strongly affected by warm (5-40 eV) bulk electron temperatures and imply multiple temperature distributions in the targets. Finally, the spatial distribution of temperature is dependent on the target thickness, and a thin target shows an advantage tomore » generate uniform warm dense conditions in a large area.« less

Experimental evidence of beam-foil plasma creation during ion-solid interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Prashant, E-mail: prashant@iuac.res.in; Nandi, Tapan

2016-08-15

Charge state evolution of the energetic projectile ions during the passage through thin carbon foils has been revisited using the X-ray spectroscopy technique. Contributions from the bulk and the solid surface in the charge changing processes have been segregated by measuring the charge state distribution of the projectile ions in the bulk of the target during the ion–solid interaction. Interestingly, the charge state distribution measured in the bulk exhibits Lorentzian profile in contrast to the well-known Gaussian structure observed using the electromagnetic methods and the theoretical predictions. The occurrence of such behavior is a direct consequence of the imbalance betweenmore » charge changing processes, which has been seen in various cases of the laboratory plasma. It suggests that the ion-solid collisions constitute high-density, localized plasma in the bulk of the solid target, called the beam-foil plasma. This condensed beam-foil plasma is similar to the high-density solar and stellar plasma which may have practical implementations in various fields, in particular, plasma physics and nuclear astrophysics. The present work suggests further modification in the theoretical charge state distribution calculations by incorporating the plasma coupling effects during the ion–solid interactions. Moreover, the multi-electron capture from the target exit surface has been confirmed through comparison between experimentally measured and theoretically predicted values of the mean charge state of the projectile ions.« less

In-Flight and Post-Flight Impact Data Analysis from DEBIE2 (Debris In-Orbit Evaluator) on Board of ISS

NASA Astrophysics Data System (ADS)

Menicucci, Alessandra; Drolshagen, Gerhard; Kuitunen, Juha; Butenko, Yuriy; Mooney, Cathal

2013-08-01

DEBIE2 (Debris-in-orbit-evaluator) was launched in February 2008 as part of the European Technology Exposure Facility (EuTEF) and installed on the exterior of Columbus on ISS. DEBIE2 is an active detector, composed by 3 sensor units able to monitor the sub-micron micro-meteoroid and debris population in space. Each DEBIE sensor consists of a thin aluminium foil coupled with 2 wire grids sensitive to the plasma generated by particles impacting on the foil where also 2 piezoelectric sensors are glued. If the particle penetrates the foil, this can be detected by a third electron plasma detector located just behind the foil. The combination of these information allows to estimate the micro-particles and debris fluxes. EuTEF and DEBIE2 were retrieved after 18 months in flight and returned to Earth with the Space Shuttle Mission STS-128. In this paper, the results of the analysis of in-flight impact data are presented as well as the comparison with the models. The DEBIE2 sensor pointing the Zenith direction, was found to have one wire of the upper grid cut in two pieces by an impact. The postflight analysis focused on this sensor and included optical and SEM/EDX scanning. The results from this inspection will be also presented in this paper.

A simple and inclusive method to determine the habit plane in transmission electron microscope based on accurate measurement of foil thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Dong, E-mail: d.qiu@uq.edu.au; Zhang, Mingxing

2014-08-15

A simple and inclusive method is proposed for accurate determination of the habit plane between bicrystals in transmission electron microscope. Whilst this method can be regarded as a variant of surface trace analysis, the major innovation lies in the improved accuracy and efficiency of foil thickness measurement, which involves a simple tilt of the thin foil about a permanent tilting axis of the specimen holder, rather than cumbersome tilt about the surface trace of the habit plane. Experimental study has been done to validate this proposed method in determining the habit plane between lamellar α{sub 2} plates and γ matrixmore » in a Ti–Al–Nb alloy. Both high accuracy (± 1°) and high precision (± 1°) have been achieved by using the new method. The source of the experimental errors as well as the applicability of this method is discussed. Some tips to minimise the experimental errors are also suggested. - Highlights: • An improved algorithm is formulated to measure the foil thickness. • Habit plane can be determined with a single tilt holder based on the new algorithm. • Better accuracy and precision within ± 1° are achievable using the proposed method. • The data for multi-facet determination can be collected simultaneously.« less

Oxide-based thin film transistors for flexible electronics

NASA Astrophysics Data System (ADS)

He, Yongli; Wang, Xiangyu; Gao, Ya; Hou, Yahui; Wan, Qing

2018-01-01

The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends. Project supported in part by the National Science Foundation for Distinguished Young Scholars of China (No. 61425020), in part by the National Natural Science Foundation of China (No. 11674162).

Solar Cells for Lunar Application

NASA Technical Reports Server (NTRS)

Freundlich, Alex; Ignatiev, Alex

1997-01-01

In this work a preliminary study of the vacuum evaporation of silicon extracted from the lunar regolith has been undertaken. An electron gun vacuum evaporation system has been adapted for this purpose. Following the calibration of the system using ultra high purity silicon deposited on Al coated glass substrates, thin films of lunar Si were evaporated on a variety of crystalline substrates as well as on glass and lightweight 1 mil (25 microns) Al foil. Extremely smooth and featureless films with essentially semiconducting properties were obtained. Optical absorption analysis sets the bandgap (about 1.1 eV) and the refractive index (n=3.5) of the deposited thin films close to that of crystalline silicon. Secondary ion mass spectroscopy and energy dispersive spectroscopy analysis indicated that these films are essentially comparable to high purity silicon and that the evaporation process resulted in a substantial reduction of impurity levels. All layers exhibited a p-type conductivity suggesting the presence of a p-type dopant in the fabricated layers. While the purity of the 'lunar waste material' is below that of the 'microelectronic-grade silicon', the vacuum evaporated material properties seems to be adequate for the fabrication of average performance Si-based devices such as thin film solar cells. Taking into account solar cell thickness requirements (greater than 10 microns) and the small quantities of lunar material available for this study, solar cell fabrication was not possible. However, the high quality of the optical and electronic properties of evaporated thin films was found to be similar to those obtained using ultra-high purity silicon suggest that thin film solar cell production on the lunar surface with in situ resource utilization may be a viable approach for electric power generation on the moon.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schultz, A.W.; Leavitt, W.Z.

A preliminary study was conducted to determine the feasiblllty of uslng neutron radiography for examining ordnance materials. Depleted U and 4140 steel castings in various thicknesses were examined. In addition, a thin section of Be, a grasshopper and a cricket were radiographed to illustrate the ability of neutrons to determine defects in low-density materials. For uranium thicknesses up to 5 in., a contrast sensitivity between 1.5 and 7.5%o was obtained using thermal neutrons, In foil, and industrial x-ray film transfer techniques. For 6 in. of U, a contrast sensitivity between 6.3 and 12.5% was obtained. For U thicknesses up tomore » 6 in., a detail sensitivity of 2.1% was obtained. For thicknesses up to 4 in. of steel, a contrast sensitivity between 1.9 and 9.4% and a detail sensitivity between 0.8 and 3.1% were obtained. For 5.125 and 6 in. of steel, contrast sensitivities between 14.6 and 29.2% and 14.6 and 39.6%, respectively, and detail sensitivities of no less than 4.9% were obtained. Both a contrast and a detail sensitivity of about 5% were obtained in examining a thin section of Be. Recommendations for further studies are given. (auth)« less

Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications

NASA Astrophysics Data System (ADS)

Kingon, Angus I.; Srinivasan, Sudarsan

2005-03-01

Replacement of noble metal electrodes by base metals significantly lowers the cost of ferroelectric, piezoelectric and dielectric devices. Here, we demonstrate that it is possible to process lead zirconate (Pb(Zr0.52Ti0.48)O3, or PZT) thin films directly on base metal copper foils. We explore the impact of the oxygen partial pressure during processing, and demonstrate that high-quality films and interfaces can be achieved through control of the oxygen partial pressure within a narrow window predicted by thermodynamic stability considerations. This demonstration has broad implications, opening up the possibility of the use of low-cost, high-conductivity copper electrodes for a range of Pb-based perovskite materials, including PZT films in embedded printed circuit board applications for capacitors, varactors and sensors; multilayer PZT piezoelectric stacks; and multilayer dielectric and electrostrictive devices based on lead magnesium niobate-lead titanate. We also point out that the capacitors do not fatigue on repeated switching, unlike those with Pt noble metal electrodes. Instead, they appear to be fatigue-resistant, like capacitors with oxide electrodes. This may have implications for ferroelectric non-volatile memories.

Strong electromagnetic pulses generated in high-intensity short-pulse laser interactions with thin foil targets

NASA Astrophysics Data System (ADS)

Rączka, P.; Dubois, J.-L.; Hulin, S.; Tikhonchuk, V.; Rosiński, M.; Zaraś-Szydłowska, A.; Badziak, J.

2017-12-01

Measurements are reported of the target neutralization current, the target charge, and the tangential component of the magnetic field generated as a result of laser-target interaction by pulses with the energy in the range of 45 mJ to 92 mJ on target and the pulse duration from 39 fs to 1000 fs. The experiment was performed at the Eclipse facility in CELIA, Bordeaux. The aim of the experiment was to extend investigations performed for the thick (mm scale) targets to the case of thin (micrometer thickness) targets in a way that would allow for a straightforward comparison of the results. We found that thin foil targets tend to generate 20 to 50 percent higher neutralization current and the target charge than the thick targets. The measurement of the tangential component of the magnetic field had shown that the initial spike is dominated by the 1 ns pulse consistent with the 1 ns pulse of the neutralization current, but there are some differences between targets of different type on sub-ns scale, which is an effect going beyond a simple picture of the target acting as an antenna. The sub-ns structure appears to be reproducible to surprising degree. We found that there is in general a linear correlation between the maximum value of the magnetic field and the maximum neutralization current, which supports the target-antenna picture, except for pulses hundreds of fs long.

Experimental depth dose curves of a 67.5 MeV proton beam for benchmarking and validation of Monte Carlo simulation

PubMed Central

Faddegon, Bruce A.; Shin, Jungwook; Castenada, Carlos M.; Ramos-Méndez, José; Daftari, Inder K.

2015-01-01

Purpose: To measure depth dose curves for a 67.5 ± 0.1 MeV proton beam for benchmarking and validation of Monte Carlo simulation. Methods: Depth dose curves were measured in 2 beam lines. Protons in the raw beam line traversed a Ta scattering foil, 0.1016 or 0.381 mm thick, a secondary emission monitor comprised of thin Al foils, and a thin Kapton exit window. The beam energy and peak width and the composition and density of material traversed by the beam were known with sufficient accuracy to permit benchmark quality measurements. Diodes for charged particle dosimetry from two different manufacturers were used to scan the depth dose curves with 0.003 mm depth reproducibility in a water tank placed 300 mm from the exit window. Depth in water was determined with an uncertainty of 0.15 mm, including the uncertainty in the water equivalent depth of the sensitive volume of the detector. Parallel-plate chambers were used to verify the accuracy of the shape of the Bragg peak and the peak-to-plateau ratio measured with the diodes. The uncertainty in the measured peak-to-plateau ratio was 4%. Depth dose curves were also measured with a diode for a Bragg curve and treatment beam spread out Bragg peak (SOBP) on the beam line used for eye treatment. The measurements were compared to Monte Carlo simulation done with geant4 using topas. Results: The 80% dose at the distal side of the Bragg peak for the thinner foil was at 37.47 ± 0.11 mm (average of measurement with diodes from two different manufacturers), compared to the simulated value of 37.20 mm. The 80% dose for the thicker foil was at 35.08 ± 0.15 mm, compared to the simulated value of 34.90 mm. The measured peak-to-plateau ratio was within one standard deviation experimental uncertainty of the simulated result for the thinnest foil and two standard deviations for the thickest foil. It was necessary to include the collimation in the simulation, which had a more pronounced effect on the peak-to-plateau ratio for the thicker foil. The treatment beam, being unfocussed, had a broader Bragg peak than the raw beam. A 1.3 ± 0.1 MeV FWHM peak width in the energy distribution was used in the simulation to match the Bragg peak width. An additional 1.3–2.24 mm of water in the water column was required over the nominal values to match the measured depth penetration. Conclusions: The proton Bragg curve measured for the 0.1016 mm thick Ta foil provided the most accurate benchmark, having a low contribution of proton scatter from upstream of the water tank. The accuracy was 0.15% in measured beam energy and 0.3% in measured depth penetration at the Bragg peak. The depth of the distal edge of the Bragg peak in the simulation fell short of measurement, suggesting that the mean ionization potential of water is 2–5 eV higher than the 78 eV used in the stopping power calculation for the simulation. The eye treatment beam line depth dose curves provide validation of Monte Carlo simulation of a Bragg curve and SOBP with 4%/2 mm accuracy. PMID:26133619

Analysis of LDEF experiment AO187-2 chemical and isotopic measurements of micrometeoroids by secondary ion mass spectrometry

NASA Technical Reports Server (NTRS)

Zinner, Ernst

1995-01-01

#Experiment AO187-2, that was flown on board the Long Duration Exposure Facility(LDEF), was designed to measure the chemical and isotopic compositions of interplanetary dust impinging on the spacecraft from outer space. Information on the nature and composition of orbital debris was also anticipated. The spacecraft maintained a constant orientation with respect to its velocity vector thereby defining leading and trailing edges that faced respectively into and away from the direction of motion. Arrays of individual capture cells each 80.8 sq cm in size and totaling 237 in number were exposed on both the leading and trailing edges of LDEF. Each cell consisted of a pure Ge target surface slightly separated from a thin (2.5 micrometers) metallized plastic 'entrance foil.' The basic concept was that incoming projectiles would penetrate the foil, strike the Ge target plate at high velocity producing a vapor-liquid cloud that would re-deposit material on the underside of the plastic foil. This material would then be analyzed using the sensitive surface analysis technique of Secondary Ion Mass Spectrometry (SIMS). In practice, most of the plastic entrance foils failed during the extended period of orbital exposure probably due to a combination of UV embrittlement, large densities of impact events and (for the leading edge) the effects of atomic oxygen erosion in orbit. However the foils failed gradually and most remained in place on the capture cells for a significant fraction of the duration of the flight . Because most of the impactors were small (less than 10 micrometers) they were heated and dispersed in traversing the entrance foils producing clouds of molten droplets and vapor that produced easily identifiable 'extended impacts' on the Ge target plates. Fortunately, it proved possible to make ion probe measurements of projectile compositions from material deposited on the Ge in the extended impact structures.

47 CFR 68.215 - Installation of other than “fully protected” system premises wiring that serves more than four...

Code of Federal Regulations, 2011 CFR

2011-10-01

... least 15 cm (6 in) (measured linearly on the cable) of conductive foil, and establishing a potential difference between the foil and all of the individual conductors connected together, such potential difference gradually increased over a 30 second time period to 1500 volts rms, 60 Hertz, then applied...

47 CFR 68.215 - Installation of other than “fully protected” system premises wiring that serves more than four...

Code of Federal Regulations, 2014 CFR

2014-10-01

... least 15 cm (6 in) (measured linearly on the cable) of conductive foil, and establishing a potential difference between the foil and all of the individual conductors connected together, such potential difference gradually increased over a 30 second time period to 1500 volts rms, 60 Hertz, then applied...

47 CFR 68.215 - Installation of other than “fully protected” system premises wiring that serves more than four...

Code of Federal Regulations, 2012 CFR

2012-10-01

... least 15 cm (6 in) (measured linearly on the cable) of conductive foil, and establishing a potential difference between the foil and all of the individual conductors connected together, such potential difference gradually increased over a 30 second time period to 1500 volts rms, 60 Hertz, then applied...

47 CFR 68.215 - Installation of other than “fully protected” system premises wiring that serves more than four...

Code of Federal Regulations, 2013 CFR

2013-10-01

... least 15 cm (6 in) (measured linearly on the cable) of conductive foil, and establishing a potential difference between the foil and all of the individual conductors connected together, such potential difference gradually increased over a 30 second time period to 1500 volts rms, 60 Hertz, then applied...

Low-cost fabrication of optical waveguides, interconnects and sensing structures on all-polymer-based thin foils

NASA Astrophysics Data System (ADS)

Rezem, Maher; Kelb, Christian; Günther, Axel; Rahlves, Maik; Reithmeier, Eduard; Roth, Bernhard

2016-03-01

Micro-optical sensors based on optical waveguides are widely used to measure temperature, force and strain but also to detect biological and chemical substances such as explosives or toxins. While optical micro-sensors based on silicon technology require complex and expensive process technologies, a new generation of sensors based completely on polymers offer advantages especially in terms of low-cost and fast production techniques. We have developed a process to integrate micro-optical components such as embedded waveguides and optical interconnects into polymer foils with a thickness well below one millimeter. To enable high throughput production, we employ hot embossing technology, which is capable of reel-to-reel fabrication with a surface roughness in the optical range. For the waveguide fabrication, we used the thermoplastic polymethylmethacrylate (PMMA) as cladding and several optical adhesives as core materials. The waveguides are characterized with respect to refractive indices and propagation losses. We achieved propagation losses are as low as 0.3 dB/cm. Furthermore, we demonstrate coupling structures and their fabrication especially suited to integrate various light sources such as vertical-cavity surface-emitting lasers (VCSEL) and organic light emitting diodes (OLED) into thin polymer foils. Also, we present a concept of an all-polymer and waveguide based deformation sensor based on intensity modulation, which can be fabricated by utilizing our process. For future application, we aim at a low-cost and high-throughput reel-to-reel production process enabling the fabrication of large sensor arrays or disposable single-use sensing structures, which will open optical sensing to a large variety of application fields ranging from medical diagnosis to automotive sensing.

Conceptual Design and Feasibility of Foil Bearings for Rotorcraft Engines: Hot Core Bearings

NASA Technical Reports Server (NTRS)

Howard, Samuel A.

2007-01-01

Recent developments in gas foil bearing technology have led to numerous advanced high-speed rotating system concepts, many of which have become either commercial products or experimental test articles. Examples include oil-free microturbines, motors, generators and turbochargers. The driving forces for integrating gas foil bearings into these high-speed systems are the benefits promised by removing the oil lubrication system. Elimination of the oil system leads to reduced emissions, increased reliability, and decreased maintenance costs. Another benefit is reduced power plant weight. For rotorcraft applications, this would be a major advantage, as every pound removed from the propulsion system results in a payload benefit.. Implementing foil gas bearings throughout a rotorcraft gas turbine engine is an important long-term goal that requires overcoming numerous technological hurdles. Adequate thrust bearing load capacity and potentially large gearbox applied radial loads are among them. However, by replacing the turbine end, or hot section, rolling element bearing with a gas foil bearing many of the above benefits can be realized. To this end, engine manufacturers are beginning to explore the possibilities of hot section gas foil bearings in propulsion engines. This overview presents a logical follow-on activity by analyzing a conceptual rotorcraft engine to determine the feasibility of a foil bearing supported core. Using a combination of rotordynamic analyses and a load capacity model, it is shown to be reasonable to consider a gas foil bearing core section. In addition, system level foil bearing testing capabilities at NASA Glenn Research Center are presented along with analysis work being conducted under NRA Cooperative Agreements.

Atomic Layer Deposition of MnS: Phase Control and Electrochemical Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riha, Shannon C.; Koegel, Alexandra A.; Meng, Xiangbo

Manganese sulfide (MnS) thin films were synthesized via atomic layer deposition (ALD) using gaseous manganese bis(ethylcyclopentadienyl) and hydrogen sulfide as precursors. At deposition temperatures ≤150 °C phase-pure r-MnS thin films were deposited, while at temperatures >150 °C, a mixed phase, consisting of both r- and a-MnS resulted. In situ quartz crystal microbalance (QCM) studies validate the self-limiting behavior of both ALD half-reactions and, combined with quadrupole mass spectrometry (QMS) allow the derivation of a self-consistent reaction mechanism. Lastly, MnS thin films were deposited on copper foil and tested as a Li-ion battery anode. The MnS coin cells showed exceptional cyclemore » stability and near-theoretical capacity.« less

Atomic Layer Deposition of MnS: Phase Control and Electrochemical Applications

DOE PAGES

Riha, Shannon C.; Koegel, Alexandra A.; Meng, Xiangbo; ...

2016-01-19

Manganese sulfide (MnS) thin films were synthesized via atomic layer deposition (ALD) using gaseous manganese bis(ethylcyclopentadienyl) and hydrogen sulfide as precursors. At deposition temperatures ≤150 °C phase-pure r-MnS thin films were deposited, while at temperatures >150 °C, a mixed phase, consisting of both r- and a-MnS resulted. In situ quartz crystal microbalance (QCM) studies validate the self-limiting behavior of both ALD half-reactions and, combined with quadrupole mass spectrometry (QMS) allow the derivation of a self-consistent reaction mechanism. Lastly, MnS thin films were deposited on copper foil and tested as a Li-ion battery anode. The MnS coin cells showed exceptional cyclemore » stability and near-theoretical capacity.« less

The feed-out process: Rayleigh-Taylor and Richtmyer-Meshkov instabilities in thin, laser-driven foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smitherman, D.P.

Eight beams carrying a shaped pulse from the NOVA laser were focused into a hohlraum with a total energy of about 25 kJ. A planar foil was placed on the side of the hohlraum with perturbations facing away from the hohlraum. All perturbations were 4 {micro}m in amplitude and 50 {micro}m in wavelength. Three foils of pure aluminum were shot with thicknesses and pulse lengths respectively of 86 {micro}m and 2. 2 ns, 50 {micro}m and 4.5 ns, and 35 {micro}m with both 2.2 ns and 4. 5 ns pulses. Two composite foils constructed respectively of 32 and 84 {micro}mmore » aluminum on the ablative side and 10 {micro}m beryllium on the cold surface were also shot using the 2.2 ns pulse. X-ray framing cameras recorded perturbation growth using both face- and side-on radiography. The LASNEX code was used to model the experiments. A shock wave interacted with the perturbation on the cold surface generating growth from a Richtmyer-Meshkov instability and a strong acoustic mode. The cold surface perturbation fed-out to the Rayleigh-Taylor unstable ablation surface, both by differential acceleration and interface coupling, where it grew. A density jump did not appear to have a large effect on feed-out from interface coupling. The Rayleigh-Taylor instability`s vortex pairs overtook and reversed the direction of flow of the Richtmyer-Meshkov vortices, resulting in the foil moving from a sinuous to a bubble and spike configuration. The Rayleigh-Taylor instability may have acted as an ablative instability on the hot surface, and as a classical instability on the cold surface, on which grew second and third order harmonics.« less

A Spark Chamber With Thin Electrodes and a Study of the Position of the Alignment Point; KAMERA S TONKIMI ELEKTRODAMI IZUCHENIE POLOZHENIYA TOCHKI SPRYAMLENIYA ISKRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Legar, F.; Nikanorov, V.I.; Peter, G.

1964-01-01

A technique for making the foil electrodes with twosided working surface for spark chambers is described. Some characteristics of spark chambers with thin electrodes are given. The variation of the distance from the negative electrode to the alignment point of a spark with the energy of the detected particles and the angie of their passage through the charaber was studied. It is shown that with the increasing initial density of the gas ionization in the chamber the Townsend coefficient a becomes greater due to the charge interaction of avalanches. (auth)

Study of wear between piston ring and cylinder housing of an internal combustion engine by thin layer activation technique

NASA Astrophysics Data System (ADS)

Chowdhury, D. P.; Chaudhuri, Jayanta; Raju, V. S.; Das, S. K.; Bhattacharjee, B. B.; Gangadharan, S.

1989-07-01

The wear analysis of a compression ring and cylinder housing of an Internal Combustion Engine by thin layer activation (TLA) with 40 MeV α-particles from the Variable Energy Cyclotron at Calcutta is reported. The calibration curves have been obtained for Fe and Ni using stacked foil activation technique for determining the absolute wear in these machine parts. It has been possible to determine the pattern of wear on the points along the surface of machine components. The minimum detectable depth in this wear study has been estimated at 0.11 ± 0.04 μm.

Measurement of the differential cross sections of 6Li(d,d0) for Ion Beam Analysis purposes

NASA Astrophysics Data System (ADS)

Ntemou, E.; Aslanoglou, X.; Axiotis, M.; Foteinou, V.; Kokkoris, M.; Lagoyannis, A.; Misaelides, P.; Patronis, N.; Preketes-Sigalas, K.; Provatas, G.; Vlastou, R.

2017-09-01

In the present work, the 6Li(d,d0)6Li elastic scattering differential cross sections were measured in the energy range Ed,lab = 940-2000 keV for Elastic Backscattering Spectroscopy (EBS) purposes, using thin lithium targets, made by evaporating isotopically enriched 6LiF powder on self-supporting carbon foils, with an ultra-thin Au layer on top for normalization purposes. The experiment was carried out in deuteron beam energy steps of 20 or 30 keV and for the laboratory scattering angles of 125°, 140°, 150°, 160°, and 170°.

Electromechanical transducer for acoustic telemetry system

DOEpatents

Drumheller, D.S.

1993-06-22

An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

Electromechanical transducer for acoustic telemetry system

DOEpatents

Drumheller, Douglas S.

1993-01-01

An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

Plasma assisted synthesis of vanadium pentoxide nanoplates

NASA Astrophysics Data System (ADS)

Singh, Megha; Sharma, Rabindar Kumar; Kumar, Prabhat; Reddy, G. B.

2015-08-01

In this work, we report the growth of α-V2O5 (orthorhombic) nanoplates on glass substrate using plasma assisted sublimation process (PASP) and Nickel as catalyst. 100 nm thick film of Ni is deposited over glass substrate by thermal evaporation process. Vanadium oxide nanoplates have been deposited treating vanadium metal foil under high vacuum conditions with oxygen plasma. Vanadium foil is kept at fixed temperature growth of nanoplates of V2O5 to take place. Samples grown have been studied using XPS, XRD and HRTEM to confirm the growth of α-phase of V2O5, which revealed pure single crystal of α- V2O5 in orthorhombic crystallographic plane. Surface morphological studies using SEM and TEM show nanostructured thin film in form of plates. Uniform, vertically aligned randomly oriented nanoplates of V2O5 have been deposited.

Transmission of ˜ 10 keV electron beams through thin ceramic foils: Measurements and Monte Carlo simulations of electron energy distribution functions

NASA Astrophysics Data System (ADS)

Morozov, A.; Heindl, T.; Skrobol, C.; Wieser, J.; Krücken, R.; Ulrich, A.

2008-07-01

Electron beams with particle energy of ~10 keV were sent through 300 nm thick ceramic (Si3N4 + SiO2) foils and the resulting electron energy distribution functions were recorded using a retarding grid technique. The results are compared with Monte Carlo simulations performed with two publicly available packages, Geant4 and Casino v2.42. It is demonstrated that Geant4, unlike Casino, provides electron energy distribution functions very similar to the experimental distributions. Both simulation packages provide a quite precise average energy of transmitted electrons: we demonstrate that the maximum uncertainty of the calculated values of the average energy is 6% for Geant4 and 8% for Casino, taking into account all systematic uncertainties and the discrepancies in the experimental and simulated data.

Differential multi-electron emission induced by swift highly charged gold ions penetrating carbon foils

NASA Astrophysics Data System (ADS)

Rothard, H.; Moshammer, R.; Ullrich, J.; Kollmus, H.; Mann, R.; Hagmann, S.; Zouros, T. J. M.

2007-05-01

First results on swift heavy ion induced electron emission from solids obtained with a reaction microscope are presented. This advanced technique, which is successfully used since quite some time to study electron ejection in ion-atom collisions, combines the measurement of the time-of-flight of electrons with imaging techniques. A combination of electric and magnetic fields guides the ejected electrons onto a position sensitive detector, which is capable to accept multiple hits. From position and time-of-flight measurement the full differential emission characteristics of up to 10 electrons per single incoming ion can be extracted. As a first example, we show energy spectra, angular distributions and the multiplicity distribution of electrons from impact of Au24+ (11 MeV/u) on a thin carbon foil (28 μg/cm2).

Experimental characterization and microstructure linked modeling of mechanical behavior of ultra-thin aluminum foils used in packaging

NASA Astrophysics Data System (ADS)

Tabourot, Laurent; Charleux, Ludovic; Balland, Pascale; Sène, Ndèye Awa; Andreasson, Eskil

2018-05-01

This paper is based on the hypothesis that introducing distribution of mechanical properties is beneficial for modeling all kinds of mechanical behavior, even of ordinary metallic materials. To bring proof of its admissibility, it has to be first shown that modeling based on this assertion is able to efficiently describe standard mechanical behavior of materials. Searching for typical study case, it has been assessed that at a low scale, yield stresses could be strongly distributed in ultrathin aluminum foils used in packaging industry, offering opportunities to identifying their distribution and showing its role on the mechanical properties. Considering initially reduced modeling allow to establish a valuable connection between the hardening curve and the distribution of local yield stresses. This serves for finding initial value of distribution parameters in a more sophisticated identification procedure. With finally limited number of representative classes of local yield stresses, concretely 3 is enough, it is shown that a 3D finite element simulation involving limited numbers of elements returns realistic behavior of an ultrathin aluminum foil exerted to tensile test, in reference to experimental results. This gives way to large possibilities in modeling in order to give back complex experimental evidence.

Beam halo collimation in heavy ion synchrotrons

NASA Astrophysics Data System (ADS)

Strašík, I.; Prokhorov, I.; Boine-Frankenheim, O.

2015-08-01

This paper presents a systematic study of the halo collimation of ion beams from proton up to uranium in synchrotrons. The projected Facility for Antiproton and Ion Research synchrotron SIS100 is used as a reference case. The concepts are separated into fully stripped (e.g., 238U92+ ) and partially stripped (e.g., 238U28+ ) ion collimation. An application of the two-stage betatron collimation system, well established for proton accelerators, is intended also for fully stripped ions. The two-stage system consists of a primary collimator (a scattering foil) and secondary collimators (bulky absorbers). Interaction of the particles with the primary collimator (scattering, momentum losses, and nuclear interactions) was simulated by using fluka. Particle-tracking simulations were performed by using mad-x. Finally, the dependence of the collimation efficiency on the primary ion species was determined. The influence of the collimation system adjustment, lattice imperfections, and beam parameters was estimated. The concept for the collimation of partially stripped ions employs a thin stripping foil in order to change their charge state. These ions are subsequently deflected towards a dump location using a beam optical element. The charge state distribution after the stripping foil was obtained from global. The ions were tracked by using mad-x.

A slow positron beam generator for lifetime studies

NASA Technical Reports Server (NTRS)

Singh, Jag J.; Eftekhari, Abe; St.clair, Terry L.

1989-01-01

A slow positron beam generator using well-annealed polycrystalline tungsten moderators and a Na-22 positron source was developed. A 250 micro c source, deposited on a 2.54 micron thick aluminized mylar, is sandwiched between two (2.54 cm x 2.54 cm x 0.0127 cm) tungsten pieces. Two (2.54 cm x 2.54 cm x t cm) test polymer films insulate the two tungsten moderator pieces from the aluminized mylar source holder (t=0.00127 to 0.0127). A potential difference of 10 to 100 volts--depending on the test polymer film thickness (t)--is applied between the tungsten pieces and the source foil. Thermalized positrons diffusing out of the moderator pieces are attracted to the source foil held at an appropriate potential below the moderator pieces. These positrons have to pass through the test polymer films before they can reach the source foil. The potential difference between the moderator pieces and the aluminized mylar is so adjusted as to force the positrons to stop in the test polymer films. Thus the new generator becomes an effective source of positrons for assaying thin polymer films for their molecular morphology.

Induction Bonding of Prepreg Tape and Titanium Foil

NASA Technical Reports Server (NTRS)

Messier, Bernadette C.; Hinkley, Jeffrey A.; Johnston, Norman J.

1998-01-01

Hybrid structural laminates made of titanium foil and carbon fiber reinforced polymer composite offer a potential for improved performance in aircraft structural applications. To obtain information needed for the automated fabrication of hybrid laminates, a series of bench scale tests were conducted of the magnetic induction bonding of titanium foil and thermoplastic prepreg tape. Foil and prepreg specimens were placed in the gap of a toroid magnet mounted in a bench press. Several magnet power supplies were used to study power at levels from 0.5 to 1.75 kW and frequencies from 50 to 120 kHz. Sol-gel surface-treated titanium foil, 0.0125 cm thick, and PIXA/IM7 prepreg tape were used in several lay-up configurations. Data were obtained on wedge peel bond strength, heating rate, and temperature ramp over a range of magnet power levels and frequencies at different "power-on" times for several magnet gap dimensions. These data will be utilized in assessing the potential for automated processing. Peel strengths of foil-tape bonds depended on the maximum temperature reached during heating and on the applied pressure. Maximum peel strengths were achieved at 1.25kW and 8OkHz. Induction heating of the foil appears to be capable of good bonding up to 10 plies of tape. Heat transfer calculations indicate that a 20-40 C temperature difference exists across the tape thickness during heat-up.

The SuperNemo ββ0ν enriched 82Se source foils and their radiopurity measurement with the BiPo-3 detector

NASA Astrophysics Data System (ADS)

Loaiza, P.; SuperNemo Collaboration

2017-09-01

The SuperNemo collaboration is currently building the SuperNemo demonstrator at the Modane Underground Laboratory, as the proof of concept for the full SuperNemo program. The enriched ββ0ν source consisting of thin foils containing 7 kg of 82Se is enclosed by the gas tracker and the plastic scintillator calorimeter. The full reconstruction of the ββ0ν event topology ensures an excellent background rejection and points at a true zero-background search. One of the most critical sources of background is a contamination in the source foils. The required radiopurity is 208Tl < 2 µBq/kg and 214Bi < 10 µBq/kg to achieve the sensitivity T1/2(ββ0ν) > 1026 years. The collaboration has developed a dedicated detector to measure the ultra high natural radiopurities requested, the BiPo-3 detector, installed in the Canfranc Underground Laboratory. The experimental design and performances of BiPo-3 are presented. Dedicated background measurements have been performed. After an exposure of about 2 years.m2 the surface activities of the scintillators of A(208Tl) = 1.0 ± 0.2 µBq/m2 and A(214Bi) = 1.0 ± 0.3 µBq/m2 are measured. Results of the 208Tl and 214Bi activity measurements of the first enriched 82Se foils of SuperNemo are also presented.

Interaction of irradiation-induced prismatic dislocation loops with free surfaces in tungsten

NASA Astrophysics Data System (ADS)

Fikar, Jan; Gröger, Roman; Schäublin, Robin

2017-02-01

The prismatic dislocation loops appear in metals as a result of high-energy irradiation. Understanding their formation and interaction is important for quantification of irradiation-induced deterioration of mechanical properties. Characterization of dislocation loops in thin foils is commonly made using transmission electron microscopy (TEM), but the results are inevitably influenced by the proximity of free surfaces. The prismatic loops are attracted to free surfaces by image forces. Depending on the type, size and depth of the loop in the foil, they can escape to the free surface, thus invalidating TEM observations and conclusions. In this article small prismatic hexagonal and circular dislocation loops in tungsten with the Burgers vectors 1/2 〈 1 1 1 〉 and 〈 1 0 0 〉 are studied by molecular statics simulations using three embedded atom method (EAM) potentials. The calculated image forces are compared to known elastic solutions. A particular attention is paid to the critical stress to move edge dislocations. The escape of the loop to the free surface is quantified by a combination of atomistic simulations and elastic calculations. For example, for the 1/2 〈 1 1 1 〉 loop with diameter 7.4 nm in a 55 nm thick foil we calculated that about one half of the loops will escape to the free surface. This implies that TEM observations detect only approx. 50% of the loops that were originally present in the foil.

Fabrication and icing property of superhydrophilic and superhydrophobic aluminum surfaces derived from anodizing aluminum foil in a sodium chloride aqueous solution

NASA Astrophysics Data System (ADS)

Song, Meirong; Liu, Yuru; Cui, Shumin; Liu, Long; Yang, Min

2013-10-01

An aluminum foil with a rough surface was first prepared by anodic treatment in a neutral aqueous solution with the help of pitting corrosion of chlorides. First, the hydrophobic Al surface (contact angle around 79°) became superhydrophilic (contact angle smaller than 5°) after the anodizing process. Secondly, the superhydrophilic Al surface became superhydrophobic (contact angle larger than 150°) after being modified by oleic acid. Finally, the icing property of superhydrophilic, untreated, and superhydrophobic Al foils were investigated in a refrigerated cabinet at -12 °C. The mean total times to freeze a water droplet (6 μL) on the three foils were 17 s, 158 s and 1604 s, respectively. Thus, the superhydrophilic surface accelerates the icing process, while the superhydrophobic surface delays the process. The main reason for this transition might mainly result from the difference of the contact area of the water droplet with Al substrate: the increase in contact area with Al substrate will accelerate the heat conduct process, as well as the icing process; the decrease in contact area with Al substrate will delay the heat conduct process, as well as the icing process. Compared to the untreated Al foil, the contact area of the water droplet with the Al substrate was higher on superhydrophilic surface and smaller on the superhydrophobic surface, which led to the difference of the heat transfer time as well as the icing time.

Flexible probe for measuring local conductivity variations in Li-ion electrode films

NASA Astrophysics Data System (ADS)

Hardy, Emilee; Clement, Derek; Vogel, John; Wheeler, Dean; Mazzeo, Brian

2018-04-01

Li-ion battery performance is governed by electronic and ionic properties of the battery. A key metric that characterizes Li-ion battery cell performance is the electronic conductivity of the electrodes, which are metal foils with thin coatings of electrochemically active materials. To accurately measure the spatial variation of electronic conductivity of these electrodes, a micro-four-line probe (μ4LP) was designed and used to non-destructively measure the properties of commercial-quality Li-ion battery films. This previous research established that the electronic conductivity of film electrodes is not homogeneous throughout the entirety of the deposited film area. In this work, a micro-N-line probe (μNLP) and a flexible micro-flex-line probe (μFLP) were developed to improve the non-destructive micro-scale conductivity measurements that we can take. These devices were validated by comparing test results to that of the predecessor, the micro-four-line probe (μ4LP), on various commercial-quality Li-ion battery electrodes. Results show that there is significant variation in conductivity on a millimeter and even micrometer length scale through the electrode film. Compared to the μ4LP, the μNLP and μFLP also introduce additional measurement configuration possibilities, while providing a more robust design. Researchers and manufacturers can use these probes to identify heterogeneity in their electrodes during the fabrication process, which will lead to the development of better batteries.

Microstructure Evolution and Composition Control during the Processing of Thin-gage Metallic Foil (Preprint)

DTIC Science & Technology

2012-02-01

the presence of somewhat randomly-distributed carbides and borides (white particles in BSE images), this grain size was comparable to that observed...pinned by carbide/ boride particles (imaging white in Figure 8c). The very fine gamma-prime precipitates likely produced during magnetron sputtering...sputtered material. First, the carbide/ boride particles were nucleated and hence located preferentially at the grain boundaries in the sputtered

Powder-metallurgy superalloy strengthened by a secondary gamma phase.

NASA Technical Reports Server (NTRS)

Kotval, P. S.

1971-01-01

Description of experiments in which prealloyed powders of superalloy compositions were consolidated by extrusion after the strengthening by precipitation of a body-centered tetragonal gamma secondary Ni3 Ta phase. Thin foil electron microscopy showed that the mechanical properties of the resultant powder-metallurgy product were correlated with its microstructure. The product exhibited high strength at 1200 F without loss of ductility, after thermomechanical treatment and aging.

High-Voltage, High-Impedance Ion Beam Production

DTIC Science & Technology

2009-06-01

the anode tube with a loosely-crumpled, thin aluminized- mylar foil. This spoils the virtual cathode and greatly reduces the neutron signal, as seen...ions follow ballistic (straight-line) trajectories in the drift tube (see Sec. VIII), then (except for the small displacement associated with bending...mTorr) ambient in the drift tube . Based on our previous experience, we would expect charge, but not necessarily current, neutralization of the beam

Direct Fabrication of a-Si:H Thin Film Transistor Arrays on Plastic and Metal Foils for Flexible Displays

DTIC Science & Technology

2008-12-01

TFTs ) arrays for high information content active matrix flexible displays for Army applications. For all flexible substrates a manufacturable...impermeable flexible substrate systems “display-ready” materials and handling protocols, (ii) high performance TFT devices and circuits fabricated...processes for integration with the flexible TFT arrays. Approaches and solution to address each of these major challenges are described in the

Unsupported palladium alloy membranes and methods of making same

DOEpatents

Way, J. Douglas; Thoen, Paul; Gade, Sabina K.

2015-06-02

The invention provides support-free palladium membranes and methods of making these membranes. Single-gas testing of the unsupported foils produced hydrogen permeabilities equivalent to thicker membranes produced by cold-rolling. Defect-free films as thin as 7.2 microns can be fabricated, with ideal H.sub.2/N.sub.2 selectivities as high as 40,000. Homogeneous membrane compositions may also be produced using these methods.

Analytical electron microscope study of the omega phase transformation in a zirconium-niobium alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaluzec, N. J.

1979-01-01

The study of the as-quenched omega phase morphology shows that the domain size of Zr-15% Nb is on the order of 30 A. No alignment of omega domains along <222>..beta.. directions was observed and samples having undergone thermal cycling in thin foil form, did not develop a long-period structure of alternating ..beta.. and ..omega.. phases below the omega transformation temperature. (FS)

X-ray metal film filters at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Keski-Kuha, Ritva A. M.

1989-01-01

Thin aluminum foil filters have been evaluated at cryogenic temperatures. The results of the test program, including cold cycling and vibration testing, indicate that these filters are fully successful at cryogenic temperatures and can provide the high X-ray transmittance and high background rejection required for the blocking filters which are being developed for the X-Ray Spectrometer, one of the focal plane instruments on the Advanced X-Ray Astrophysics Facility.

Self-proton/ion radiography of laser-produced proton/ion beam from thin foil targets

NASA Astrophysics Data System (ADS)

Paudel, Y.; Renard-Le Galloudec, N.; Nicolai, Ph.; d'Humieres, E.; Ya. Faenov, A.; Kantsyrev, V. L.; Safronova, A. S.; Shrestha, I.; Osborne, G. C.; Shlyaptseva, V. V.; Sentoku, Y.

2012-12-01

Protons and multicharged ions generated from high-intensity laser interactions with thin foil targets have been studied with a 100 TW laser system. Protons/ions with energies up to 10 MeV are accelerated either from the front or the rear surface of the target material. We have observed for the first time that the protons/ions accelerated from the front surface of the target, in a direction opposite to the laser propagation direction, are turned around and pulled back to the rear surface, in the laser propagation direction. This proton/ion beam is able to create a self-radiograph of the target and glass stalk holding the target itself recorded through the radiochromic film stack. This unique result indicates strong long-living (ns time scale) magnetic fields present in the laser-produced plasma, which are extremely important in energy transport during the intense laser irradiation. The magnetic field from laser main pulse expands rapidly in the preformed plasma to rotate the laser produced protons. Radiation hydrodynamic simulations and ray tracing found that the magnetic field created by the amplified spontaneous emission prepulse is not sufficient to explain the particle trajectories, but the additional field created by the main pulse interaction estimated from particle-in-cell simulation is able to change the particle trajectories.

Evolution of sausage and helical modes in magnetized thin-foil cylindrical liners driven by a Z-pinch

NASA Astrophysics Data System (ADS)

Yager-Elorriaga, D. A.; Lau, Y. Y.; Zhang, P.; Campbell, P. C.; Steiner, A. M.; Jordan, N. M.; McBride, R. D.; Gilgenbach, R. M.

2018-05-01

In this paper, we present experimental results on axially magnetized (Bz = 0.5 - 2.0 T), thin-foil (400 nm-thick) cylindrical liner-plasmas driven with ˜600 kA by the Michigan Accelerator for Inductive Z-Pinch Experiments, which is a linear transformer driver at the University of Michigan. We show that: (1) the applied axial magnetic field, irrespective of its direction (e.g., parallel or anti-parallel to the flow of current), reduces the instability amplitude for pure magnetohydrodynamic (MHD) modes [defined as modes devoid of the acceleration-driven magneto-Rayleigh-Taylor (MRT) instability]; (2) axially magnetized, imploding liners (where MHD modes couple to MRT) generate m = 1 or m = 2 helical modes that persist from the implosion to the subsequent explosion stage; (3) the merging of instability structures is a mechanism that enables the appearance of an exponential instability growth rate for a longer than expected time-period; and (4) an inverse cascade in both the axial and azimuthal wavenumbers, k and m, may be responsible for the final m = 2 helical structure observed in our experiments. These experiments are particularly relevant to the magnetized liner inertial fusion program pursued at Sandia National Laboratories, where helical instabilities have been observed.

Simulations of laser-driven ion acceleration from a thin CH target

NASA Astrophysics Data System (ADS)

Park, Jaehong; Bulanov, Stepan; Ji, Qing; Steinke, Sven; Treffert, Franziska; Vay, Jean-Luc; Schenkel, Thomas; Esarey, Eric; Leemans, Wim; Vincenti, Henri

2017-10-01

2D and 3D computer simulations of laser driven ion acceleration from a thin CH foil using code WARP were performed. As the foil thickness varies from a few nm to μm, the simulations confirm that the acceleration mechanism transitions from the RPA (radiation pressure acceleration) to the TNSA (target normal sheath acceleration). In the TNSA regime, with the CH target thickness of 1 μ m and a pre-plasma ahead of the target, the simulations show the production of the collimated proton beam with the maximum energy of about 10 MeV. This agrees with the experimental results obtained at the BELLA laser facility (I 5 × 18 W / cm2 , λ = 800 nm). Furthermore, the maximum proton energy dependence on different setups of the initialization, i.e., different angles of the laser incidence from the target normal axis, different gradient scales and distributions of the pre-plasma, was explored. This work was supported by LDRD funding from LBNL, provided by the U.S. DOE under Contract No. DE-AC02-05CH11231, and used resources of the NERSC, a DOE office of Science User Facility supported by the U.S. DOE under Contract No. DE-AC02-05CH11231.

Simulations of bremsstrahlung emission in ultra-intense laser interactions with foil targets

NASA Astrophysics Data System (ADS)

Vyskočil, Jiří; Klimo, Ondřej; Weber, Stefan

2018-05-01

Bremsstrahlung emission from interactions of short ultra-intense laser pulses with solid foils is studied using particle-in-cell (PIC) simulations. A module for simulating bremsstrahlung has been implemented in the PIC loop to self-consistently account for the dynamics of the laser–plasma interaction, plasma expansion, and the emission of gamma ray photons. This module made it possible to study emission from thin targets, where refluxing of hot electrons plays an important role. It is shown that the angular distribution of the emitted photons exhibits a four-directional structure with the angle of emission decreasing with the increase of the width of the target. Additionally, a collimated forward flash consisting of high energy photons has been identified in thin targets. The conversion efficiency of the energy of the laser pulse to the energy of the gamma rays rises with both the driving pulse intensity, and the thickness of the target. The amount of gamma rays also increases with the atomic number of the target material, despite a lower absorption of the driving laser pulse. The angular spectrum of the emitted gamma rays is directly related to the increase of hot electron divergence during their refluxing and its measurement can be used in experiments to study this process.

In-situ TEM observation of nano-void formation in UO2 under irradiation

NASA Astrophysics Data System (ADS)

Sabathier, C.; Martin, G.; Michel, A.; Carlot, G.; Maillard, S.; Bachelet, C.; Fortuna, F.; Kaitasov, O.; Oliviero, E.; Garcia, P.

2014-05-01

Transmission electron microscopy (TEM) observations of UO2 polycrystals irradiated in situ with 4 MeV Au ions were performed at room temperature (RT) to better understand the mechanisms of cavity and ultimately fission products nucleation in UO2. Experiments were carried out at the JANNuS Orsay facility that enables in situ ion irradiations inside the microscope to be carried out. The majority of 4 MeV gold ions were transmitted through the thin foil, and the induced radiation defects were investigated by TEM. Observations showed that nano-void formation occurs at ambient temperature in UO2 thin foils irradiated with energetic heavy ions under an essentially nuclear energy loss regime. The diameter and density of nano-objects were measured as a function of the gold irradiation dose at RT. A previous paper has also revealed a similar nano-object population after a Xe implantation performed at 390 keV at 870 K. The nano-object density was modelled using simple concepts derived from Classical Molecular Dynamics simulations. The results are in good agreement, which suggests a mechanism of heterogeneous nucleation induced by energetic cascade overlaps. This indicates that nano-void formation mechanism is controlled by radiation damage. Such nanovoids are likely to act as sinks for mobile fission products during reactor operation.

Formation of 100-nm periodic structures on a titanium surface by exploiting the oxidation and third harmonic generation induced by femtosecond laser pulses.

PubMed

Li, Xian-Feng; Zhang, Cheng-Yun; Li, Hui; Dai, Qiao-Feng; Lan, Sheng; Tie, Shao-Long

2014-11-17

Periodic surface structures with periods as small as about one-tenth of the irradiating femtosecond (fs) laser light wavelength were created on the surface of a titanium (Ti) foil by exploiting laser-induced oxidation and third harmonic generation (THG). They were achieved by using 100-fs laser pulses with a repetition rate of 1 kHz and a wavelength ranging from 1.4 to 2.2 μm. It was revealed that an extremely thin TixOy layer was formed on the surface of the Ti foil after irradiating fs laser light with a fluence smaller than the ablation threshold of Ti, leading to a significant enhancement in THG which may exceed the ablation threshold of TixOy. As compared with Ti, the maximum efficacy factor for TixOy appears at a larger normalized wavevector in the direction perpendicular to the polarization of the fs laser light. As a result, the THG-dominated laser ablation of TixOy induces 100-nm periodic structures parallel to the polarization of the fs laser light. The depth of the periodic structures was found to be ~10 nm by atomic force microscopy and the formation of the thin TixOy layer was verified by energy dispersive X-ray spectroscopy.

Frictional behavior of atomically thin sheets: hexagonal-shaped graphene islands grown on copper by chemical vapor deposition.

PubMed

Egberts, Philip; Han, Gang Hee; Liu, Xin Z; Johnson, A T Charlie; Carpick, Robert W

2014-05-27

Single asperity friction experiments using atomic force microscopy (AFM) have been conducted on chemical vapor deposited (CVD) graphene grown on polycrystalline copper foils. Graphene substantially lowers the friction force experienced by the sliding asperity of a silicon AFM tip compared to the surrounding oxidized copper surface by a factor ranging from 1.5 to 7 over loads from the adhesive minimum up to 80 nN. No damage to the graphene was observed over this range, showing that friction force microscopy serves as a facile, high contrast probe for identifying the presence of graphene on Cu. Consistent with studies of epitaxially grown, thermally grown, and mechanically exfoliated graphene films, the friction force measured between the tip and these CVD-prepared films depends on the number of layers of graphene present on the surface and reduces friction in comparison to the substrate. Friction results on graphene indicate that the layer-dependent friction properties result from puckering of the graphene sheet around the sliding tip. Substantial hysteresis in the normal force dependence of friction is observed with repeated scanning without breaking contact with a graphene-covered region. Because of the hysteresis, friction measured on graphene changes with time and maximum applied force, unless the tip slides over the edge of the graphene island or contact with the surface is broken. These results also indicate that relatively weak binding forces exist between the copper foil and these CVD-grown graphene sheets.

Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications

NASA Technical Reports Server (NTRS)

Radil, Kevin C.; DellaCorte, Christopher

2009-01-01

Foil gas bearings under development for rotorcraft-sized, hot core engine applications have been susceptible to damage from the slow acceleration and rates typically encountered during the pre-ignition stage in conventional engines. Recent laboratory failures have been assumed to be directly linked to operating foil bearings below their lift-off speed while following conventional startup procedures for the engines. In each instance, the continuous sliding contact between the foils and shaft was believed to thermally overload the bearing and cause the engines to fail. These failures highlight the need to characterize required acceleration rates and minimum operating speeds for these applications. In this report, startup experiments were conducted with a large, rotorcraft engine sized foil bearing under moderate load and acceleration rates to identify the proper start procedures needed to avoid bearing failure. The results showed that a bearing under a 39.4 kPa static load can withstand a modest acceleration rate of 500 rpm/s and excessive loitering below the bearing lift-off speed provided an adequate solid lubricant is present.

Uniaxial creep property and viscoelastic-plastic modelling of ethylene tetrafluoroethylene (ETFE) foil

NASA Astrophysics Data System (ADS)

Li, Yintang; Wu, Minger

2015-02-01

Ethylene tetrafluoroethylene (ETFE) foil has been widely used in spatial structures for its light weight and high transparency. This paper studies short- and long-term creep properties of ETFE foil. Two series of short-term creep and recovery tests were performed, in which residual strain was observed. A long-term creep test of ETFE foil was also conducted and lasted about 400 days. A viscoelastic-plastic model was then established to describe short-term creep and recovery behaviour of ETFE foil. This model contains a traditional generalised Kelvin part and an added steady-flow component to represent viscoelastic and viscoplastic behaviour, respectively. The model can fit tests' data well at three stresses and six temperatures. Additionally, time-temperature superposition was adopted to simulate long-term creep behaviour of ETFE foil. Horizontal shifting factors were determined by W.L.F. equation in which transition temperature was simulated by shifting factors. Using this equation, long-term creep behaviours at three temperatures were predicted. The results of the long-term creep test showed that a short-term creep test at identical temperatures was insufficient to predict additional creep behaviour, and the long-term creep test verified horizontal shifting factors which were derived from the time-temperature superposition.

Spectroscopic Measurements of Planar Foil Plasmas Driven by a MA LTD

NASA Astrophysics Data System (ADS)

Patel, Sonal; Yager-Elorriaga, David; Steiner, Adam; Jordan, Nick; Gilgenbach, Ronald; Lau, Y. Y.

2014-10-01

Planar foil ablation experiments are being conducted on the Linear Transformer Driver (LTD) at the University of Michigan. The experiment consists of a 400 nm-thick, Al planar foil and a current return post. An optical fiber is placed perpendicular to the magnetic field and linear polarizers are used to isolate the pi and sigma lines. The LTD is charged to +/-70 kV with approximately 400-500 kA passing through the foil. Laser shadowgraphy has previously imaged the plasma and measured anisotropy in the Magneto Rayleigh-Taylor (MRT) instability. Localized magnetic field measurements using Zeeman splitting during the current rise is expected to yield some insight into this anisotropy. Initial experiments use Na D lines of Al foils seeded with sodium to measure Zeeman splitting. Several ion lines are also currently being studied, such as Al III and C IV, to probe the higher temperature core plasma. In planned experiments, several lens-coupled optical fibers will be placed across the foil, and local magnetic field measurements will be taken to measure current division within the plasma. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant DGE 1256260.

Investigation of the charged particle nuclear reactions on natural boron for the purposes of the thin layer activation (TLA)

NASA Astrophysics Data System (ADS)

Ditrói, F.; Takács, S.; Tárkányi, F.; Fenyvesi, A.; Bergman, J.; Heselius, S.-J.; Solin, O.

1995-12-01

Boron of natural composition was investigated in the form of NiBSi metallic-glass foil to determine the cross-section functions of the natB(p,x) 7Be and the natB(d,x) 7Be nuclear reactions. These reactions are very important from the point of view of Thin Layer Activation (TLA) technique to monitor the wear of boron-containing superhard materials (e.g. BN), because the 7Be with its half-life of 53 d and gamma-energy of 447 keV is very suitable for wear measurements. The possibility of recoil-implantation of the radioactive nuclei was also studied.

Production of medically useful bromine isotopes via alpha-particle induced nuclear reactions

NASA Astrophysics Data System (ADS)

Breunig, Katharina; Scholten, Bernhard; Spahn, Ingo; Hermanne, Alex; Spellerberg, Stefan; Coenen, Heinz H.; Neumaier, Bernd

2017-09-01

The cross sections of α-particle induced reactions on arsenic leading to the formation of 76,77,78Br were measured from their respective thresholds up to 37 MeV. Thin sediments of elemental arsenic powder were irradiated together with Al degrader and Cu monitor foils using the established stacked-foil technique. For determination of the effective α-particle energies and of the effective beam current through the stacks the cross-section ratios of the monitor nuclides 67Ga/66Ga were used. This should help resolve discrepancies in existing literature data. Comparison of the data with the available excitation functions shows some slight energy shifts as well as some differences in curve shapes. The calculated thick target yields indicate, that 77Br can be produced in the energy range Eα = 25 → 17 MeV free of isotopic impurities in quantities sufficient for medical application.

Ferro- and piezoelectric properties of polar-axis-oriented CaBi4Ti4O15 films

NASA Astrophysics Data System (ADS)

Kato, Kazumi; Fu, Desheng; Suzuki, Kazuyuki; Tanaka, Kiyotaka; Nishizawa, Kaori; Miki, Takeshi

2004-05-01

Polar-axis-oriented CaBi4Ti4O15 (CBTi144) films were fabricated on Pt foils using a complex metal alkoxide solution. The 500-nm-thick film showed the columnar structure and consisted of well-developed grains. The a/b-axis orientation of the ferroelectric films is considered to be associated with the preferred orientation of Pt foil. The film showed good ferro- and piezoelectric properties. The Pr and Ec were 25 μC/cm2 and 306 kV/cm, respectively, at an applied voltage of 115 V. The d33 was characterized as 30 pm/V by piezoresponse force microscopy. The values were twice as large as those of the CBTi144 thin film with random orientation. The polar-axis-oriented CBTi144 films would open up possibilities for devices as Pb-free piezoelectric materials.

High temperature superconductor dc-SQUID microscope with a soft magnetic flux guide

NASA Astrophysics Data System (ADS)

Poppe, U.; Faley, M. I.; Zimmermann, E.; Glaas, W.; Breunig, I.; Speen, R.; Jungbluth, B.; Soltner, H.; Halling, H.; Urban, K.

2004-05-01

A scanning SQUID microscope based on high-temperature superconductor (HTS) dc-SQUIDs was developed. An extremely soft magnetic amorphous foil was used to guide the flux from room temperature samples to the liquid-nitrogen-cooled SQUID sensor and back. The flux guide passes through the pick-up loop of the HTS SQUID, providing an improved coupling of magnetic flux of the object to the SQUID. The device measures the z component (direction perpendicular to the sample surface) of the stray field of the sample, which is rastered with submicron precision in the x-y direction by a motorized computer-controlled scanning stage. A lateral resolution better than 10 µm, with a field resolution of about 0.6 nT Hz-1/2 was achieved for the determination of the position of the current carrying thin wires. The presence of the soft magnetic foil did not significantly increase the flux noise of the SQUID.

Excitation functions of nuclear reactions induced by alpha particles up to 42 MeV on natTi for monitoring purposes and TLA

NASA Astrophysics Data System (ADS)

Hermanne, A.; Sonck, M.; Takács, S.; Szelecsényi, F.; Tárkányi, F.

1999-05-01

Excitation functions for the reactions induced by alpha particles on natTi foils and leading to the formation of 44m,44g,46,47,48Sc; 48,51Cr and 48V were determined using the stacked foil technique for energies from the respective reaction thresholds up to 42 MeV. The new experimental values are compared to earlier literature values and generally good accordance is found. It appears that the natTi(α,x) 51Cr reaction is particularly useful for monitoring α-beams in the 10-20 MeV region while for energies above 20 MeV the natTi(α,x) 47Sc reaction or the natTi(α,x) 48V reaction are more suited. The excitation functions established can be used to determine calibration curves for thin layer activation (TLA) as well.

First-Principle Investigation on the Bonding Mechanism of the Silicon Particles on the Copper Foil in Cold Spraying

NASA Astrophysics Data System (ADS)

Song, Jun; Liu, Juanfang; Chen, Qinghua

For lithium-ion batteries, the composite silicon-based electrodes can prevent from losing electrical contact and hence retain the capacity over many cycles. To uncover the adhesion mechanism on the interface formed by the copper foil and the thin silicon coatings during the cold gas dynamic spraying (CGDS) at the microscopic level, the first-principle calculations are performed to investigate the interface properties between them. The ideal work of adhesion, fracture toughness and the interface electronic properties are analyzed. It is found that all the atoms on the interface have vertical displacements, and covalent and ionic bonds are formed between the interfacial Cu and Si atoms which increases the bonding strength. However, the ideal work of adhesion on the interface is lower than one of the Cu bulk and Si bulk, so that fracture would be easier to take place on the interface.

Influence of Clay Platelet Spacing on Oxygen Permeability of Thin Film Assemblies

NASA Astrophysics Data System (ADS)

Priolo, Morgan; Gamboa, Daniel; Grunlan, Jaime

2010-03-01

Thin films of anionic natural montmorrilonite clay and various polyelectrolytes have been produced by alternately dipping a plastic substrate into dilute aqueous mixtures containing each ingredient in an effort to show the influence of clay platelet spacing on thin film permeability. After polymer-clay layers have been sequentially deposited, the resulting transparent films exhibit a brick wall nanostructure comprised of completely exfoliated clay bricks in polymeric mortar. This brick wall forms an extremely tortuous path for a molecule to traverse, creating channels perpendicular to the concentration gradient that increase the molecule's diffusion length and delay its transmission. To a first approximation, greater clay spacing (i.e., reduced clay concentration) produces greater oxygen barrier. Oxygen transmission rates below 0.005 cm^3/m^2.day have been achieved for films with only eight clay layers (total thickness of only 200 nm). With optical transparencies greater than 86% and the ability to be microwaved, these thin film composites are good candidates for flexible electronics packaging and foil replacement for food.

Multi-Spectral Solar Telescope Array. IV - The soft X-ray and extreme ultraviolet filters

NASA Technical Reports Server (NTRS)

Lindblom, Joakim F.; O'Neal, Ray H.; Walker, Arthur B. C., Jr.; Powell, Forbes R.; Barbee, Troy W., Jr.; Hoover, Richard B.

1991-01-01

NASA's Multi-Spectral Solar Telescope Array uses various combinations of thin foil filters composed of Al, C, Te, Be, Mo, Rh, and phthalocyanine to achieve the requisite radiation-rejection characteristics. Such rejection is demanded by the presence of strong EUV radiation at longer wavelengths where the specular reflectivity of multilayer mirrors can cause 'contamination' of the image in the narrow band defined by the Bragg condition.

Array of planar membrane modules for producing hydrogen

DOEpatents

Vencill, Thomas R [Albuquerque, NM; Chellappa, Anand S [Albuquerque, NM; Rathod, Shailendra B [Hillsboro, OR

2012-05-08

A shared or common environment membrane reactor containing a plurality of planar membrane modules with top and bottom thin foil membranes supported by both an intermediary porous support plate and a central base which has both solid extended members and hollow regions or a hollow region whereby the two sides of the base are in fluid communication. The membrane reactor operates at elevate temperatures for generating hydrogen from hydrogen rich feed fuels.

Beam Propagation Experimental Study.

DTIC Science & Technology

1983-04-01

pressures, the beam front velocity is limited by the rate at which the gas can be ionized. The first portion of the beam is lost due to radial electric...from the ionized- gas electrons and low-energy secondaries by a thin graphite sheet in the original array developed during the FX-25 exper- iments. The...calorimeter in vacuum, and isolated from the ionized- gas channel by a Titanium foil. The results of these measurements indicated that the energy

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacheco, Robin Montoya; Alexander, David John; Mccabe, Rodney James

2017-01-20

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Almore » cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.« less

Light management in flexible OLEDs

NASA Astrophysics Data System (ADS)

Harkema, Stephan; Pendyala, Raghu K.; Geurts, Christian G. C.; Helgers, Paul L. J.; Levell, Jack W.; Wilson, Joanne S.; MacKerron, Duncan

2014-10-01

Organic light-emitting diodes (OLEDs) are a promising lighting technology. In particular OLEDs fabricated on plastic foils are believed to hold the future. These planar devices are subject to various optical losses, which requires sophisticated light management solutions. Flexible OLEDs on plastic substrates are as prone to losses related to wave guiding as devices on glass. However, we determined that OLEDs on plastic substrates are susceptible to another loss mode due to wave guiding in the thin film barrier. With modeling of white polymer OLEDs fabricated on PEN substrates, we demonstrate that this loss mode is particularly sensitive to polarized light emission. Furthermore, we investigated how thin film barrier approaches can be combined with high index light extraction layers. Our analysis shows that OLEDs with a thin film barrier consisting of an inorganic/organic/inorganic layer sequence, a low index inorganic negatively affects the OLED efficiency. We conclude that high index inorganics are more suitable for usage in high efficiency flexible OLEDs.

Ultra-thin smart acoustic metasurface for low-frequency sound insulation

NASA Astrophysics Data System (ADS)

Zhang, Hao; Xiao, Yong; Wen, Jihong; Yu, Dianlong; Wen, Xisen

2016-04-01

Insulating low-frequency sound is a conventional challenge due to the high areal mass required by mass law. In this letter, we propose a smart acoustic metasurface consisting of an ultra-thin aluminum foil bonded with piezoelectric resonators. Numerical and experimental results show that the metasurface can break the conventional mass law of sound insulation by 30 dB in the low frequency regime (<1000 Hz), with an ultra-light areal mass density (<1.6 kg/m2) and an ultra-thin thickness (1000 times smaller than the operating wavelength). The underlying physical mechanism of such extraordinary sound insulation performance is attributed to the infinite effective dynamic mass density produced by the smart resonators. It is also demonstrated that the excellent sound insulation property can be conveniently tuned by simply adjusting the external circuits instead of modifying the structure of the metasurface.

Grid-connected polymer solar panels: initial considerations of cost, lifetime, and practicality.

PubMed

Medford, Andrew J; Lilliedal, Mathilde R; Jørgensen, Mikkel; Aarø, Dennis; Pakalski, Heinz; Fyenbo, Jan; Krebs, Frederik C

2010-09-13

Large solar panels were constructed from polymer solar cell modules prepared using full roll-to-roll (R2R) manufacture based on the previously published ProcessOne. The individual flexible polymer solar modules comprising multiple serially connected single cell stripes were joined electrically and laminated between a 4 mm tempered glass window and black Tetlar foil using two sheets of 0.5 mm thick ethylene vinyl acetate (EVA). The panels produced up to 8 W with solar irradiance of ~960 Wm⁻², and had outer dimensions of 1 m x 1.7 m with active areas up to 9180 cm². Panels were mounted on a tracking station and their output was grid connected between testing. Several generations of polymer solar cells and panel constructions were tested in this context to optimize the production of polymer solar panels. Cells lacking a R2R barrier layer were found to degrade due to diffusion of oxygen after less than a month, while R2R encapsulated cells showed around 50% degradation after 6 months but suffered from poor performance due to de-lamination during panel production. A third generation of panels with various barrier layers was produced to optimize the choice of barrier foil and it was found that the inclusion of a thin protective foil between the cell and the barrier foil is critical. The findings provide a preliminary foundation for the production and optimization of large-area polymer solar panels and also enabled a cost analysis of solar panels based on polymer solar cells.

Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52MeV.

PubMed

Ditrói, F; Takács, S; Haba, H; Komori, Y; Aikawa, M

2016-12-01

Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. The radioisotope 117m Sn is a very important theranostic (therapeutic + diagnostic) radioisotope, so special care was taken to the results for that isotope. The well-established stacked foil technique followed by gamma-spectrometry with HPGe gamma spectrometers were used. The target and monitor foils in the stack were commercial high purity metal foils. From the irradiated targets 117m Sn, 113 Sn, 110 Sn, 117m,g In, 116m In, 115m In, 114m In, 113m In, 111 In, 110m,g In, 109m In, 108m,g In, 115g Cd and 111m Cd were identified and their excitation functions were derived. The results were compared with the data of the previous measurements from the literature and with the results of the theoretical nuclear reaction model code calculations TALYS 1.8 (TENDL-2015) and EMPIRE 3.2 (Malta). From the cross section curves thick target yields were calculated and compared with the available literature data. Copyright © 2016 Elsevier Ltd. All rights reserved.

The recognition and interpretation of micro-particle impacts on space craft surfaces

NASA Astrophysics Data System (ADS)

Kearsley, Anton

Modern analysis instruments now allow the rapid examination of returned spacecraft surfaces, enabling the location and identification of impact features, and the attribution of their impactor origins. This paper describes application of novel electron, ion and micro-X-ray Fluorescence techniques to impacts on diverse compositions of substrate, including solar cell glass, poly-sulfone and fluoro-polymer-impregnated glass fibre composites, multilayer insulation foils, aluminium and titanium alloys. Examples will include two generations of solar cells and stiffener materials from the Hubble Space Telescope (HST), Beta-cloth from the NASA Mir-Trek cover blanket, aluminised Kapton foils from the Japanese Space Flyer Unit (SFU) and the European Retrievable Carrier (EuReCa), Al-alloy plates from the Long Duration Exposure Facility (LDEF), Al foils from the NASA Stardust mission, Al-alloy and Zinc orthotitanate (ZOT) painted alloy plate from HST, and titanium alloys from a re-entered titanium pressure tank. Each type of spacecraft surface poses unique problems of analysis, especially in the recognition of extraneous signatures from the impacting particle, especially if a complex chemical composition is already present in the target. For example, solar cells provide an excellent capture and analysis medium for monitoring fluxes of micrometre-scale orbital debris from solid rocket motor firings in low Earth orbit. However, they provide a hard and dense capture medium upon which substantial modification of the impactor may occur, making the precise identification of micrometeoroid components difficult. Unfortunately, extensive spallation by larger (> 100 micrometre) particle impacts on the thin and brittle structure of solar cells also usually results in complete loss of impactor signature. Although thick alloy surfaces may prevent complete impact penetration, the analysis of particle residues within their deep concavity has proven difficult, until the recent introduction of new high-efficiency energy dispersive X-ray (EDX) detectors. Along with Particle Induced X-ray Emission and micro-XRF imaging systems, the new EDX detectors allow recognition of subtle trace quantities of residue from even millimetre-scale craters and thin foil penetrations. Data from these differing substrates and techniques need to be integrated if we are to fully document micro-particle populations from the wide range of natural (cometary and asteroidal, i.e. micrometeoroid) and artificial (i.e. orbital debris) sources.

Fabrication of high-performance supercapacitors based on transversely oriented carbon nanotubes

NASA Astrophysics Data System (ADS)

Markoulidis, F.; Lei, C.; Lekakou, C.

2013-04-01

High-performance supercapacitors with organic electrolyte 1 M TEABF4 (tetraethyl ammonium tetrafluoroborate) in PC (propylene carbonate) were fabricated and tested, based on multiwall carbon nanotubes (MWNTs) deposited by electrophoresis on three types of alternative substrates: aluminium foil, ITO (indium tin oxide) coated PET (polyethylene terephthalate) film and PET film. In all cases, SEM (scanning electron microscopy) and STEM (scanning transmission electron microscopy) micrographs demonstrated that protruding, transversely oriented MWNT structures were formed, which should increase the transverse conductivity of these MWNT electrodes. The best supercapacitor cell of MWNT electrodes deposited on aluminium foil displayed good transverse orientation of the MWNT structures as well as an in-plane MWNT network at the feet of the protruding structures, which ensured good in-plane conductivity. Capacitor cells with MWNT electrodes deposited either on ITO-coated PET film or on PET film demonstrated lower but still very good performance due to the high density of transversely oriented MWNT structures (good transverse conductivity) but some in-plane inhomogeneities. Capacitor cells with drop-printed MWNTs on aluminium foil, without any transverse orientation, had 16-30 times lower specific capacitance and 5-40 times lower power density than the capacitor cells with the electrophoretically deposited MWNT electrodes.

Growth of a sea urchin-like rutile TiO2 hierarchical microsphere film on Ti foil for a quasi-solid-state dye-sensitized solar cell.

PubMed

Ri, Jin Hyok; Wu, Shufang; Jin, Jingpeng; Peng, Tianyou

2017-11-30

A sea urchin-like rutile TiO 2 microsphere (RMS) film was fabricated on Ti foil via a hydrothermal process. The resulting rutile TiO 2 hierarchical microspheres with a diameter of 5-6 μm are composed of nanorods with a diameter of ∼200 nm and a length of 1-2 μm. The sea urchin-like hierarchical structure leads to the Ti foil-based RMS film possessing much better light-scattering capability in the visible region than the bare Ti foil. By using it as an underlayer of a nanosized anatase TiO 2 film (bTPP3) derived from a commercially available paste (TPP3), the corresponding bilayer Ti foil-based quasi-solid-state dye-sensitized solar cell (DSSC) only gives a conversion efficiency of 4.05%, much lower than the single bTPP3 film-based one on Ti foil (5.97%). By spin-coating a diluted TPP3 paste (sTPP3) on the RMS film prior to scraping the bTPP3 film, the resulting RMS/sTPP3/bTPP3 film-based DSSC achieves a significantly enhanced efficiency (7.27%). The electrochemical impedance spectra (EIS) show that the RMS/sTPP3/bTPP3 film possesses better electron transport capability and longer electron lifetime than the bTPP3 film. This work not only provides the first example of directly growing rutile TiO 2 hierarchically structured microsphere film on Ti foil suitable for replacing the rigid, heavy and expensive transparent conductive oxide (TCO) glass substrate to serve as a light-scattering underlayer of Ti foil-based quasi-solid-state DSSCs, but also paves a new route to develop Ti foil-based flexible DSSCs with high efficiency, low cost and a wide application field through optimizing the composition and structure of the photoanode.

Neutron capture cross-section measurements for 238U between 0.4 and 1.4 MeV

NASA Astrophysics Data System (ADS)

Krishichayan, Fnu; Finch, S. W.; Howell, C. R.; Tonchev, A. P.; Tornow, W.

2017-09-01

Neutron-induced radiative-capture cross-section data of 238U are crucial for fundamental nuclear physics as well as for Stewardship Science, for advanced-fuel-cycle calculations, and for nuclear astrophysics. Based on different techniques, there are a large number of 238U(n, γ) 239U cross-section data available in the literature. However, there is a lack of systematic and consistent measurements in the 0.1 to 3.0 MeV energy range. The goal of the neutron-capture project at TUNL is to provide accurate 238U(n, γ) 239U cross-section data in this energy range. The 238U samples, sandwiched between gold foils of the same size, were irradiated for 8-14 hours with monoenergetic neutrons. To avoid any contribution from thermal neutrons, the 238U and 197Au targets were placed inside of a thin-walled pill-box made of 238U. Finally, the whole pill-box was wrapped in a gold foil as well. After irradiation, the samples were gamma-counted at the TUNL's low-background counting facility using high-efficient HPGe detectors. The 197Au monitor foils were used to calculate the neutron flux. The experimental technique and 238U(n, γ) 239U cross-section results at 6 energies will be discussed during the meeting.

A simple method for the measurement of reflective foil emissivity

NASA Astrophysics Data System (ADS)

Ballico, M. J.; van der Ham, E. W. M.

2013-09-01

Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to "bubble-wrap". Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a "primary method" and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

NASA Astrophysics Data System (ADS)

Robinson, Timothy; Giltrap, Samuel; Eardley, Samuel; Consoli, Fabrizio; De Angelis, Riccardo; Ingenito, Francesco; Stuart, Nicholas; Verona, Claudio; Smith, Roland A.

2018-01-01

We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm) and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with <1 MHz standard deviations of the peak position. This deviation is reduced for shots taken on the same day, suggesting that local conditions, such as movement of metal objects within the target chamber, are more likely to lead to minor spectral modifications, highlighting the role of the local environment in determining the details of EMP production. Levitated targets are electrically isolated from their environment, hence these targets should be unable to draw a neutralization current from the earth following ejection of hot electrons from the plasma, in contrast to predictions for pin-mounted foils in the Poyé EMP generation model. With levitated targets, no EMP was measurable above the noise threshold of any diagnostic, despite observation of protons accelerated to >30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

Direct growth of hexagonal boron nitride/graphene heterostructures on cobalt foil substrates by plasma-assisted molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Zhongguang; Khanaki, Alireza; Tian, Hao

2016-07-25

Graphene/hexagonal boron nitride (G/h-BN) heterostructures have attracted a great deal of attention because of their exceptional properties and wide variety of potential applications in nanoelectronics. However, direct growth of large-area, high-quality, and stacked structures in a controllable and scalable way remains challenging. In this work, we demonstrate the synthesis of h-BN/graphene (h-BN/G) heterostructures on cobalt (Co) foil by sequential deposition of graphene and h-BN layers using plasma-assisted molecular beam epitaxy. It is found that the coverage of h-BN layers can be readily controlled on the epitaxial graphene by growth time. Large-area, uniform-quality, and multi-layer h-BN films on thin graphite layersmore » were achieved. Based on an h-BN (5–6 nm)/G (26–27 nm) heterostructure, capacitor devices with Co(foil)/G/h-BN/Co(contact) configuration were fabricated to evaluate the dielectric properties of h-BN. The measured breakdown electric field showed a high value of ∼2.5–3.2 MV/cm. Both I-V and C-V characteristics indicate that the epitaxial h-BN film has good insulating characteristics.« less

A simple method for the measurement of reflective foil emissivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballico, M. J.; Ham, E. W. M. van der

Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to 'bubble-wrap'. Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity,more » and the standard ASTM-E408 is implied. Unfortunately this standard is not a 'primary method' and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.« less

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

NASA Astrophysics Data System (ADS)

Zhao, Jie; Zhou, Guangmin; Yan, Kai; Xie, Jin; Li, Yuzhang; Liao, Lei; Jin, Yang; Liu, Kai; Hsu, Po-Chun; Wang, Jiangyan; Cheng, Hui-Ming; Cui, Yi

2017-10-01

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed LixM (M = Si, Sn, or Al) nanoparticles encapsulated by large graphene sheets. With the protection of graphene sheets, the large and freestanding LixM/graphene foils are stable in different air conditions. With fully expanded LixSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). This foil is also paired with high-capacity Li-free V2O5 and sulfur cathodes to achieve stable full-cell cycling.

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

DOE PAGES

Zhao, Jie; Zhou, Guangmin; Yan, Kai; ...

2017-07-10

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed Li xM (M = Si, Sn, or Al) nanoparticles encapsulated by largemore » graphene sheets. With the protection of graphene sheets, the large and freestanding Li xM/graphene foils are stable in different air conditions. With fully expanded Li xSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). As a result, this foil is also paired with high-capacity Li-free V 2O 5 and sulfur cathodes to achieve stable full-cell cycling.« less

Air-stable and freestanding lithium alloy/graphene foil as an alternative to lithium metal anodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Jie; Zhou, Guangmin; Yan, Kai

Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed Li xM (M = Si, Sn, or Al) nanoparticles encapsulated by largemore » graphene sheets. With the protection of graphene sheets, the large and freestanding Li xM/graphene foils are stable in different air conditions. With fully expanded Li xSi confined in the highly conductive and chemically stable graphene matrix, this LixSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). As a result, this foil is also paired with high-capacity Li-free V 2O 5 and sulfur cathodes to achieve stable full-cell cycling.« less

Evaluation of Advanced Solid Lubricant Coatings for Foil Air Bearings Operating at 25 and 500 C

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Fellenstein, James A.; Benoy, Patricia A.

1998-01-01

The tribological properties of one chrome oxide and one chrome carbide based solid lubricant coating were evaluated in a partial-arc foil bearing at 25 and 500 C. Start/stop bearing operation up to 20,000 cycles were run under 10 kPa (1.5 psi) static deadweight load. Bearing friction (torque) was measured during the test. Specimen wear and SEM/EDS surface analyses were conducted after testing to understand and elucidate the tribological characteristics observed. The chrome oxide coating which contains both (Ag) and (BaF2/CaF2) for low and high temperature lubrication, exhibited low friction in sliding against Al2O3 coated foils at 25 and 500 C. The chrome carbide coating, which lacked a low temperature lubricant but contained BaF2/CaF2 as a high temperature lubricant, exhibited high friction at 25 C and low friction at 500 C against both bare and Al2O3 coated superalloy foil surfaces. Post test surface analyses suggest that improved tribological performance is exhibited when a lubricant film from the coating transfers to the foil surface.

SU-F-T-424: Mitigation of Increased Surface Dose When Treating Through A Carbon Fiber Couch Top

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, E; Misgina, F

Purpose: To study the effect of the Varian carbon fiber couch top on surface dose for patients being treated using single PA beams in the supine position and to identify simple methods for surface dose reduction. Methods: Measurements of surface dose were obtained in Solid Water phantoms using both a parallel plate ionization chamber (PTW Advanced Markus) and EBT2 Radiochromic films for both 6 and 10MV photons. All measurements were referenced to a depth considered a typical for PA Spine fields. Techniques used to reduce the surface dose included introducing an air standoff using Styrofoam sheets to suspend the phantommore » surface above the couch top and by adding a thin high Z scattering foil on the table surface. Surface doses were evaluated for typical field sizes, standoff heights, and various scattering materials. Comparisons were made to the surface dose obtainable when treating through a Varian Mylar covered tennis racket style couch top. Results: Dependence on typical spine field sizes was relatively minor. Dependence on air gap was much more significant. Surface doses decreased exponentially with increases in air standoff distance. Surface doses were reduced by approximately 50% for an air gap of 10cm and 40% for a 15cm air gap. Surface doses were reduced by an additional 15% by the addition of a 1mm Tin scattering foil. Conclusion: Using simple techniques, it is possible to reduce the surface dose when treating single PA fields through the Varian carbon fiber couch top. Surface doses can be reduced to levels observed when treating though transparent Mylar tops by adding about 15 cm of air gap. Further reductions are possible by adding thin scattering foils, such as Tin or Lead, on the couch surface. This is a low cost approach to reduce surface dose when using the Varian carbon fiber couch top.« less

Low to moderate temperature nanolaminate heater

DOEpatents

Eckels, J Del [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Hau-Riege, Stefan [Fremont, CA; Walton, Chris [Oakland, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

2011-01-11

A low to moderate temperature heat source comprising a high temperature energy source modified to output low to moderate temperatures wherein the high temperature energy source modified to output low to moderate temperatures is positioned between two thin pieces to form a close contact sheath. In one embodiment the high temperature energy source modified to output low to moderate temperatures is a nanolaminate multilayer foil of reactive materials that produces a heating level of less than 200.degree. C.

Requirements, Technology and Configuration Evaluation for Crash Survivable Flight Data Recording (CSFDR) System

DTIC Science & Technology

1981-03-23

25% Rotational angle - 350 degrees Temperature range - -65°C to + 125°C Vibration - 15 g Shock - 50 g Rotational load life - 25,000,000...structed of multi-layered metal foils, vacuum deposited on thin films of Mylar, Kapton, or similar plastics) slowly outgas and contaminate their own...armor. Intumescent coating is a paint derivative, which swells 5 to 50 times its original thickness when exposed to high temperatures ( 350 ° to 500

Observation of Transonic Ionization Fronts in Low-Density Foam Targets

NASA Astrophysics Data System (ADS)

Hoarty, D.; Barringer, L.; Vickers, C.; Willi, O.; Nazarov, W.

1999-04-01

Transonic ionization fronts have been observed in low-density chlorinated foam targets using time-resolved K-shell absorption spectroscopy. The front was driven by an intense pulse of soft x rays produced by high-power laser irradiation of a thin foil. The density and temperature profiles inferred from the radiographs provided detailed measurement of the conditions at a number of times. The experimental data were compared to radiation hydrodynamics simulations and reasonable agreement was obtained.

First measurement of the VESUVIO neutron spectrum in the 30-80 MeV energy range using a Proton Recoil Telescope technique

NASA Astrophysics Data System (ADS)

Cazzaniga, C.; Tardocchi, M.; Croci, G.; Frost, C.; Giacomelli, L.; Grosso, G.; Hjalmarsson, A.; Rebai, M.; Rhodes, N. J.; Schooneveld, E. M.; Gorini, G.

2013-11-01

Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV < En < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum.

Asymmetric Electrochemical Capacitors - Stretching the Limits of Aqueous Electrolytes

DTIC Science & Technology

2011-07-01

controlled atmosphere (no need for a dry room or glove box), simplifying the fabrication and packaging process. The use of a faradaic material with a fi...than the thin (25 μ m) aluminum foil current collectors used in nonaqueous EDLCs. The corrosion of these current collectors must also be minimized...valid OMB control number. 1. REPORT DATE JUL 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Asymmetric

Osteoblasts Interaction with PLGA Membranes Functionalized with Titanium Film Nanolayer by PECVD. In vitro Assessment of Surface Influence on Cell Adhesion during Initial Cell to Material Interaction

PubMed Central

Terriza, Antonia; Vilches-Pérez, José I.; González-Caballero, Juan L.; de la Orden, Emilio; Yubero, Francisco; Barranco, Angel; Gonzalez-Elipe, Agustín R.; Vilches, José; Salido, Mercedes

2014-01-01

New biomaterials for Guided Bone Regeneration (GBR), both resorbable and non-resorbable, are being developed to stimulate bone tissue formation. Thus, the in vitro study of cell behavior towards material surface properties turns a prerequisite to assess both biocompatibility and bioactivity of any material intended to be used for clinical purposes. For this purpose, we have developed in vitro studies on normal human osteoblasts (HOB®) HOB® osteoblasts grown on a resorbable Poly (lactide-co-glycolide) (PLGA) membrane foil functionalized by a very thin film (around 15 nm) of TiO2 (i.e., TiO2/PLGA membranes), designed to be used as barrier membrane. To avoid any alteration of the membranes, the titanium films were deposited at room temperature in one step by plasma enhanced chemical vapour deposition. Characterization of the functionalized membranes proved that the thin titanium layer completely covers the PLGA foils that remains practically unmodified in their interior after the deposition process and stands the standard sterilization protocols. Both morphological changes and cytoskeletal reorganization, together with the focal adhesion development observed in HOB osteoblasts, significantly related to TiO2 treated PLGA in which the Ti deposition method described has revealed to be a valuable tool to increase bioactivity of PLGA membranes, by combining cell nanotopography cues with the incorporation of bioactive factors. PMID:28788538

Al/Cu Dissimilar Friction Stir Welding with Ni, Ti, and Zn Foil as the Interlayer for Flow Control, Enhancing Mechanical and Metallurgical Properties

NASA Astrophysics Data System (ADS)

Sahu, Prakash Kumar; Pal, Sukhomay; Pal, Surjya K.

2017-07-01

This research investigates the effects of Ni, Ti, and Zn foil as interlayer, inserted between the faying edges of Al and Cu plates, for controlled intermetallic compound (IMC) formation. The weld tensile strength with Ti and Zn as interlayer is superior to Al base metal strength. This is due to controlled flow of IMCs by diffused Ti interlayer and thin, continuous, and uniform IMC formation in the case of Zn interlayer. Improved flexural stress was observed with interlayer. Weld microhardness varied with different interlayers and purely depends on IMCs present at the indentation point, flow of IMCs, and interlayer hardness. Specimens with interlayer failed at the interface of the nugget and thermomechanical-affected zone (TMAZ) with complete and broken three-dimensional (3-D) grains, indicating transgranular fracture. Phase analysis revealed that Al/Cu IMCs are impeded by Ni and Ti interlayer. The minor binary and ternary IMC phases form adjacent to the interlayer due to diffusion of the material with Al/Cu. Line scan and elemental mapping indicate thin, continuous, and uniform IMCs with enhanced weld metallurgical and mechanical properties for the joints with Zn interlayer. Macrostructural analysis revealed IMC flow variations with and without interlayer. Variation in grain size at different zones is also observed for different interlayers.

LHCb VELO upgrade

NASA Astrophysics Data System (ADS)

Hennessy, Karol; LHCb VELO Upgrade Collaboration

2017-02-01

The upgrade of the LHCb experiment, scheduled for LHC Run-III, scheduled to start in 2021, will transform the experiment to a trigger-less system reading out the full detector at 40 MHz event rate. All data reduction algorithms will be executed in a high-level software farm enabling the detector to run at luminosities of 2×1033 cm-2 s-1. The Vertex Locator (VELO) is the silicon vertex detector surrounding the interaction region. The current detector will be replaced with a hybrid pixel system equipped with electronics capable of reading out at 40 MHz. The upgraded VELO will provide fast pattern recognition and track reconstruction to the software trigger. The silicon pixel sensors have 55×55 μm2 pitch, and are read out by the VeloPix ASIC, from the Timepix/Medipix family. The hottest region will have pixel hit rates of 900 Mhits/s yielding a total data rate of more than 3 Tbit/s for the upgraded VELO. The detector modules are located in a separate vacuum, separated from the beam vacuum by a thin custom made foil. The foil will be manufactured through milling and possibly thinned further by chemical etching. The material budget will be minimised by the use of evaporative CO2 coolant circulating in microchannels within 400 μm thick silicon substrates. The current status of the VELO upgrade is described and latest results from operation of irradiated sensor assemblies are presented.

Electron emission from condensed phase material induced by fast protons.

PubMed

Shinpaugh, J L; McLawhorn, R A; McLawhorn, S L; Carnes, K D; Dingfelder, M; Travia, A; Toburen, L H

2011-02-01

Monte Carlo track simulation has become an important tool in radiobiology. Monte Carlo transport codes commonly rely on elastic and inelastic electron scattering cross sections determined using theoretical methods supplemented with gas-phase data; experimental condensed phase data are often unavailable or infeasible. The largest uncertainties in the theoretical methods exist for low-energy electrons, which are important for simulating electron track ends. To test the reliability of these codes to deal with low-energy electron transport, yields of low-energy secondary electrons ejected from thin foils have been measured following passage of fast protons. Fast ions, where interaction cross sections are well known, provide the initial spectrum of low-energy electrons that subsequently undergo elastic and inelastic scattering in the material before exiting the foil surface and being detected. These data, measured as a function of the energy and angle of the emerging electrons, can provide tests of the physics of electron transport. Initial measurements from amorphous solid water frozen to a copper substrate indicated substantial disagreement with MC simulation, although questions remained because of target charging. More recent studies, using different freezing techniques, do not exhibit charging, but confirm the disagreement seen earlier between theory and experiment. One now has additional data on the absolute differential electron yields from copper, aluminum and gold, as well as for thin films of frozen hydrocarbons. Representative data are presented.

Electron emission from condensed phase material induced by fast protons†

PubMed Central

Shinpaugh, J. L.; McLawhorn, R. A.; McLawhorn, S. L.; Carnes, K. D.; Dingfelder, M.; Travia, A.; Toburen, L. H.

2011-01-01

Monte Carlo track simulation has become an important tool in radiobiology. Monte Carlo transport codes commonly rely on elastic and inelastic electron scattering cross sections determined using theoretical methods supplemented with gas-phase data; experimental condensed phase data are often unavailable or infeasible. The largest uncertainties in the theoretical methods exist for low-energy electrons, which are important for simulating electron track ends. To test the reliability of these codes to deal with low-energy electron transport, yields of low-energy secondary electrons ejected from thin foils have been measured following passage of fast protons. Fast ions, where interaction cross sections are well known, provide the initial spectrum of low-energy electrons that subsequently undergo elastic and inelastic scattering in the material before exiting the foil surface and being detected. These data, measured as a function of the energy and angle of the emerging electrons, can provide tests of the physics of electron transport. Initial measurements from amorphous solid water frozen to a copper substrate indicated substantial disagreement with MC simulation, although questions remained because of target charging. More recent studies, using different freezing techniques, do not exhibit charging, but confirm the disagreement seen earlier between theory and experiment. One now has additional data on the absolute differential electron yields from copper, aluminum and gold, as well as for thin films of frozen hydrocarbons. Representative data are presented. PMID:21183539

Note: Mechanical in situ exfoliation of van der Waals materials

NASA Astrophysics Data System (ADS)

Pásztor, Á.; Scarfato, A.; Renner, Ch.

2017-07-01

Exfoliation, namely, the peeling of layered materials down to a single unit-cell thin foil, opens promising avenues to fabricate novel electronic materials. New properties and original functionalities emerge in the single and few layer configurations of a number of layered compounds, in particular in transition metal dichalcogenides. However, many of these thin exfoliated materials are very sensitive to ambient conditions impeding the exploration of this new and fascinating parameter space. Here we describe a method of mechanical exfoliation in ultra-high vacuum (UHV). This technique is easily adaptable to any UHV system and allows preparing and studying air sensitive nanoflakes in situ. We present the basic design and proof-of-concept scanning tunneling microscopy imaging of VSe2 nanoflakes.

Overheating instability of a thin conductor with respect to stratification

NASA Astrophysics Data System (ADS)

Garanin, S. F.; Kuznetsov, S. D.

2018-04-01

We consider an overheating instability of a thin (compared to the skin depth) conductor with respect to stratification at the stage when its resistivity rises up to an electrical explosion. Temperature perturbations under such conditions are shown to grow in proportion to resistivity. In the model, when resistivity is proportional to temperature, perturbations grow in proportion to temperature and hence exhibit no relative growth. For a conductor with initial thickness perturbations, temperature perturbations grow in proportion to resistivity and current action integral, i.e., somewhat faster than perturbations in the problem of constant thickness conductors. Comparison of our results with simulations of the growth of stratification during electrical heating of foils in warm dense matter generation systems demonstrates their close agreement.

Study of deuteron induced reactions on natural iron and copper and their use for monitoring beam parameters and for thin layer activation technique

NASA Astrophysics Data System (ADS)

Takács, S.; Tárkányi, F.; Sonck, M.; Hermanne, A.; Sudár, S.

1997-02-01

Excitation functions of deuteron induced nuclear reactions on natural iron and copper have been studied in the frame of a systematic investigation of charged particle induced nuclear reactions on metals for different applications. The excitation functions were measured up to 20 MeV deuteron energy by using stacked foil technique and activation method. The measured and the evaluated literature data showed that some reaction can be recommended for monitoring deuteron beams, and the excitation functions can be used to determine calibration curves for Thin Layer Activation Technique (TLA). Cross sections calculated by statistical model theory, STAPRE, taking into account preequilibrium effect are in reasonable agreement with the experimental results.

Recent progress of flexible AMOLED displays

NASA Astrophysics Data System (ADS)

Pang, Huiqing; Rajan, Kamala; Silvernail, Jeff; Mandlik, Prashant; Ma, Ruiqing; Hack, Mike; Brown, Julie J.; Yoo, Juhn S.; Jung, Sang-Hoon; Kim, Yong-Cheol; Byun, Seung-Chan; Kim, Jong-Moo; Yoon, Soo-Young; Kim, Chang-Dong; Hwang, Yong-Kee; Chung, In-Jae; Fletcher, Mark; Green, Derek; Pangle, Mike; McIntyre, Jim; Smith, Randal D.

2011-03-01

Significant progress has been made in recent years in flexible AMOLED displays and numerous prototypes have been demonstrated. Replacing rigid glass with flexible substrates and thin-film encapsulation makes displays thinner, lighter, and non-breakable - all attractive features for portable applications. Flexible AMOLEDs equipped with phosphorescent OLEDs are considered one of the best candidates for low-power, rugged, full-color video applications. Recently, we have demonstrated a portable communication display device, built upon a full-color 4.3-inch HVGA foil display with a resolution of 134 dpi using an all-phosphorescent OLED frontplane. The prototype is shaped into a thin and rugged housing that will fit over a user's wrist, providing situational awareness and enabling the wearer to see real-time video and graphics information.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demarest, J.A.

A study of the extreme-ultraviolet radiation emitted by ion beams of highly ionized neon and argon after passage through thin foils was conducted. A grazing-incidence spectrometer was equipped with a position-sensitive microchannel plate (MCP) detector, which improved the detection efficiency by two orders of magnitude. The position information of the MCP was determined to be linear over 90% of the 50-mm-wide detector. Spectra spanning regions of over 100 A were accumulated at a resolution of less than 1 A. A wavelength calibration based on a second order equation of spectrometer position was found to result in an accuracy of -more » 0.1 A. Over 40 transitions of Ne VIII, Ne IX, and Ne X were observed in the wavelength region from 350 to 30 A from n=2-3,4,5; n=3-4,5,6,7,8; n=4-6,7; and n=5-9. An intensity calibration of the detection system allowed the determination of the relative populations of n=3 states of Ne VIII and Ne IX. An overpopulation of states with low orbital angular momenta support electron-capture predictions by the first-order Born approximation. The argon beam-foil data confirmed the wavelength predictions of 30 previously unobserved transitions in the wavlength region from 355 to 25 A from n=2-2; n=3-4; n=4-5,6,7; and n=6-8. Lifetime determinations were made by the simultaneous measurement of 26 argon lines in the spectral region from 295-180 A. Many of the n=2-2 transitions agreed well with theory.« less

Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti

PubMed Central

2011-01-01

We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices. PMID:21711844

Thermal and Lorentz Force Analysis of Beryllium Windows for the Rectilinear Muon Cooling Channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Tianhuan; Li, D.; Virostek, S.

Reduction of the 6-dimensional phase-space of a muon beam by several orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. The channel consists of a series of low frequency (325 MHz-650 MHz) normal conducting pillbox cavities, which are enclosed with thin beryllium windows (foils) to increase shunt impedance and give a higher field on-axis for a given amount of power. These windows are subject to ohmic heating from RF currents and Lorentz force from the EM field in the cavity, both of which willmore » produce out of the plane displacements that can detune the cavity frequency. In this study, using the TEM3P code, we report on a detailed thermal and mechanical analysis for the actual Be windows used on a 325 MHz cavity in a vacuum ionization cooling rectilinear channel for a Muon Collider.« less

Thermal and Lorentz force analysis of beryllium windows for a rectilinear muon cooling channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, T.; Stratakis, D.; Li, D.

Reduction of the 6-dimensional phase-space of a muon beam by several orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. The channel consists of a series of low frequency (325 MHz-650 MHz) normal conducting pillbox cavities, which are enclosed with thin beryllium windows (foils) to increase shunt impedance and give a higher field on-axis for a given amount of power. These windows are subject to ohmic heating from RF currents and Lorentz force from the EM field in the cavity, both of which willmore » produce out of the plane displacements that can detune the cavity frequency. In this study, using the TEM3P code, we report on a detailed thermal and mechanical analysis for the actual Be windows used on a 325 MHz cavity in a vacuum ionization cooling rectilinear channel for a Muon Collider.« less

Simulations of a Molecular Cloud experiment using CRASH

NASA Astrophysics Data System (ADS)

Trantham, Matthew; Keiter, Paul; Vandervort, Robert; Drake, R. Paul; Shvarts, Dov

2017-10-01

Recent laboratory experiments explore molecular cloud radiation hydrodynamics. The experiment irradiates a gold foil with a laser producing x-rays to drive the implosion or explosion of a foam ball. The CRASH code, an Eulerian code with block-adaptive mesh refinement, multigroup diffusive radiation transport, and electron heat conduction developed at the University of Michigan to design and analyze high-energy-density experiments, is used to perform a parameter search in order to identify optically thick, optically thin and transition regimes suitable for these experiments. Specific design issues addressed by the simulations are the x-ray drive temperature, foam density, distance from the x-ray source to the ball, as well as other complicating issues such as the positioning of the stalk holding the foam ball. We present the results of this study and show ways the simulations helped improve the quality of the experiment. This work is funded by the LLNL under subcontract B614207 and NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956.

Multiple ion beam irradiation for the study of radiation damage in materials

NASA Astrophysics Data System (ADS)

Taller, Stephen; Woodley, David; Getto, Elizabeth; Monterrosa, Anthony M.; Jiao, Zhijie; Toader, Ovidiu; Naab, Fabian; Kubley, Thomas; Dwaraknath, Shyam; Was, Gary S.

2017-12-01

The effects of transmutation produced helium and hydrogen must be included in ion irradiation experiments to emulate the microstructure of reactor irradiated materials. Descriptions of the criteria and systems necessary for multiple ion beam irradiation are presented and validated experimentally. A calculation methodology was developed to quantify the spatial distribution, implantation depth and amount of energy-degraded and implanted light ions when using a thin foil rotating energy degrader during multi-ion beam irradiation. A dual ion implantation using 1.34 MeV Fe+ ions and energy-degraded D+ ions was conducted on single crystal silicon to benchmark the dosimetry used for multi-ion beam irradiations. Secondary Ion Mass Spectroscopy (SIMS) analysis showed good agreement with calculations of the peak implantation depth and the total amount of iron and deuterium implanted. The results establish the capability to quantify the ion fluence from both heavy ion beams and energy-degraded light ion beams for the purpose of using multi-ion beam irradiations to emulate reactor irradiated microstructures.

Suprathermal electrons in kJ-laser produced plasmas: M- shell resolved high-resolution x-ray spectroscopic study of transient matter evolution

NASA Astrophysics Data System (ADS)

Condamine, F. P.; Šmíd, M.; Renner, O.; Dozières, M.; Thais, F.; Angelo, P.; Bobin, J.-L.; Rosmej, F. B.

2016-05-01

Hot electrons are of key importance to understand many physical processes in plasma physics. They impact strongly on atomic physics as almost all radiative properties are seriously modified. X-ray spectroscopy is of particular interest due to reduced photoabsorption in dense matter. We report on a study of the copper Kα X-ray emission conducted at the ns, kJ laser facility PALS, Prague, Czech Republic. Thin copper foils have been irradiated with 1ω pulses. Two spherically bent quartz Bragg crystal spectrometers with high spectral and spatial resolution have been set up simultaneously to achieve a high level of confidence in the spectral distribution. In particular, an emission on the red wing of the Kα2 transition (λ = 1.5444 Å) could be identified with complex atomic structure calculations. We discuss possible implications for the analysis of non-equilibrium phenomena and present first atomic physics simulations.

Effect of interfacial interactions on the thermal conductivity and interfacial thermal conductance in tungsten–graphene layered structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu

2014-09-01

Graphene film was deposited by microwave plasma assisted deposition on polished oxygen free high conductivity copper foils. Tungsten–graphene layered film was formed by deposition of tungsten film by magnetron sputtering on the graphene covered copper foils. Tungsten film was also deposited directly on copper foil without graphene as the intermediate film. The tungsten–graphene–copper samples were heated at different temperatures up to 900 °C in argon atmosphere to form an interfacial tungsten carbide film. Tungsten film deposited on thicker graphene platelets dispersed on silicon wafer was also heated at 900 °C to identify the formation of tungsten carbide film by reaction of tungstenmore » with graphene platelets. The films were characterized by scanning electron microscopy, Raman spectroscopy, and x-ray diffraction. It was found that tungsten carbide film formed at the interface upon heating only above 650 °C. Transient thermoreflectance signal from the tungsten film surface on the samples was collected and modeled using one-dimensional heat equation. The experimental and modeled results showed that the presence of graphene at the interface reduced the cross-plane effective thermal conductivity and the interfacial thermal conductance of the layer structure. Heating at 650 and 900 °C in argon further reduced the cross-plane thermal conductivity and interface thermal conductance as a result of formation nanocrystalline tungsten carbide at the interface leading to separation and formation of voids. The present results emphasize that interfacial interactions between graphene and carbide forming bcc and hcp elements will reduce the cross-plane effective thermal conductivity in composites.« less

Laser-driven x-ray and neutron source development for industrial applications of plasma accelerators

NASA Astrophysics Data System (ADS)

Brenner, C. M.; Mirfayzi, S. R.; Rusby, D. R.; Armstrong, C.; Alejo, A.; Wilson, L. A.; Clarke, R.; Ahmed, H.; Butler, N. M. H.; Haddock, D.; Higginson, A.; McClymont, A.; Murphy, C.; Notley, M.; Oliver, P.; Allott, R.; Hernandez-Gomez, C.; Kar, S.; McKenna, P.; Neely, D.

2016-01-01

Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal operation of high power laser-solid interactions for neutron and x-ray beam generation. Measurements and Monte Carlo radiation transport simulations show that neutron yield is increased by a factor ~2 when a 1 mm copper foil is placed behind a 2 mm lithium foil, compared to using a 2 cm block of lithium only. We explore x-ray generation with a 10 picosecond drive pulse in order to tailor the spectral content for radiography with medium density alloy metals. The impact of using  >1 ps pulse duration on laser-accelerated electron beam generation and transport is discussed alongside the optimisation of subsequent bremsstrahlung emission in thin, high atomic number target foils. X-ray spectra are deconvolved from spectrometer measurements and simulation data generated using the GEANT4 Monte Carlo code. We also demonstrate the unique capability of laser-driven x-rays in being able to deliver single pulse high spatial resolution projection imaging of thick metallic objects. Active detector radiographic imaging of industrially relevant sample objects with a 10 ps drive pulse is presented for the first time, demonstrating that features of 200 μm size are resolved when projected at high magnification.

Euromir '95: first results from the Dustwatch-P detectors of the european space exposure facility

NASA Astrophysics Data System (ADS)

Shrine, N. R. G.; McDonnell, J. A. M.; Burchell, M. J.; Gardner, D. J.; Jolly, H. S.; Ratcliff, P. R.; Thomson, R.

A small, passive, retrievable dust detector/collector experiment (Dustwatch-P), based on thin foil and aerogel capture cells has been developed at the University of Kent by the Unit for Space Sciences & Astrophysics (USSA). It was mounted in the European Space Exposure Facility (ESEF) designed by the Institut d'Astrophysique Spatial (Orsay, France) and flown on the joint ESA/Russian Space Agency EuroMir '95 mission. The experiment sampled micrometeoroids and space debris in the immediate vicinity of a large space facility (Mir) and offers the opportunity for detailed particle characterisation by intact capture. Dustwatch-P was housed in 2 ESEF cassettes, each contained: 1849mm^2 of aluminium foil capture cells, 2.4mum and 5mum thick respectively, mounted above a pure copper plate; 8450mm^2 of 12mm thick silica aerogel (density of 0.1 g/cm^3 and pore size of approximately 0.07mum). 8650mm^2 of experiment-holder surfaces (highly polished 6061-T6 aluminium alloy) were also used for detection. The foils and experiment-holder surfaces readily give a flux measurement for comparison to previous data with chemical classification of any impactor residues. The aerogel was intended to capture, with minimal modification, incident hypervelocity particles. Dustwatch-P was exposed to the space environment when the ESEF cassettes were opened during Mir EVA's on the 20/21 October '95. The cassettes were hermetically sealed in space for return to Earth in February '96. We present the first results of post-flight analysis. A hypervelocity perforation has been found in each foil and a region of ejecta impacts indicating a large impact in the vicinity. This impact rate gives a higher flux than expected, possibly due to a debris cloud.

Calibration of time of flight detectors using laser-driven neutron source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirfayzi, S. R.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.

2015-07-15

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Barium Transport Process in Impregnated Dispenser Cathodes.

DTIC Science & Technology

1982-01-25

experiments were carried out on pure tungsten. The tung- sten was either in the form of thin foils (6 mm on a side) or single crystal disks (6 mm in...temperature reveal the presence of car- bon, silicon , calcium, and nitrogen impurities, with only trace amounts (ɚ%) of calcium and nitrogen. Carbon is not...expected to be present at diffusion temperatures but forms as an overlayer only upon cooling [6]. We hope to re- duce silicon impurity levels by use of

Calibration of time of flight detectors using laser-driven neutron source.

PubMed

Mirfayzi, S R; Kar, S; Ahmed, H; Krygier, A G; Green, A; Alejo, A; Clarke, R; Freeman, R R; Fuchs, J; Jung, D; Kleinschmidt, A; Morrison, J T; Najmudin, Z; Nakamura, H; Norreys, P; Oliver, M; Roth, M; Vassura, L; Zepf, M; Borghesi, M

2015-07-01

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Calibration of time of flight detectors using laser-driven neutron source

NASA Astrophysics Data System (ADS)

Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Krygier, A. G.; Green, A.; Alejo, A.; Clarke, R.; Freeman, R. R.; Fuchs, J.; Jung, D.; Kleinschmidt, A.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.

2015-07-01

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

Design and Simulation of a Spin Rotator for Longitudinal Field Measurements in the Low Energy Muons Spectrometer

NASA Astrophysics Data System (ADS)

Salman, Z.; Prokscha, T.; Keller, P.; Morenzoni, E.; Saadaoui, H.; Sedlak, K.; Shiroka, T.; Sidorov, S.; Suter, A.; Vrankovic, V.; Weber, H.-P.

We usedGeant4 to accurately model the low energy muons (LEM) beam line, including scattering due to the 10-nm thin carbon foil in the trigger detector. Simulations of the beam line transmission give excellent agreement with experimental results for beam energies higher than ∼ 12keV.We use these simulations to design and model the operation of a spin rotator for the LEM spectrometer, which will enable longitudinal field measurements in the near future.

Cross section TEM characterization of high-energy-Xe-irradiated U-Mo

DOE PAGES

Ye, B.; Jamison, L.; Miao, Y.; ...

2017-03-09

U-Mo alloys irradiated with 84 MeV Xe ions to various doses were characterized with transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques. The TEM thin foils were prepared perpendicular to the irradiated surface to allow a direct observation of the entire region modified by ions. Furthermore, depth-selective microstructural information was revealed. Varied irradiation-induced phenomena such as gas bubble formation, phase reversal, and recrystallization were observed at different ion penetration depths in U-Mo.

Interaction of high-intensity laser radiation with metals.

NASA Technical Reports Server (NTRS)

Linlor, W. I.

1971-01-01

The interaction is characterized by the production of plasma, within which the primary absorption occurs. Absorption of laser radiation by a plasma may occur by several processes. The absorption process called 'inverse bremsstrahlung' is discussed. The interaction of a laser beam with the plasma produced from a thick metal target was studied. The results of the measurements of the ion kinetic energies are presented in a graph. In addition to measurements with thick targets, information was also obtained with a thin foil of gold.

Honeycomb-Fin Heat Sink

NASA Technical Reports Server (NTRS)

Rippel, Wally E.

1989-01-01

Improved finned heat sink for electronic components more lightweight, inexpensive, and efficient. Designed for use with forced air, easily scaled up to dissipate power up to few hundred watts. Fins are internal walls of aluminum honeycomb structure. Cell structure gives strength to thin aluminum foil. Length of channels chosen for thermodynamic efficency; columns of cells combined in any reasonable number because flowing air distributed to all. Heat sink cools nearly as effectively at ends as near its center, no matter how many columns of cells combined.

Silver-Foil Psychrometer for Measuring Leaf Water Potential in situ.

PubMed

Hoffman, G J; Rawlins, S L

1972-09-01

The water potential of leaves in situ can be measured without temperature control with a miniature, single-junction psychrometer constructed from silver foil and attached to the leaf with a silver-impregnated, conductive coating. The temperature of the psychrometer has been found to stay within 0.025 degrees C of the temperature of a simulated leaf when the latter temperature was changing at a rate of 1 degrees C per minute. Leaf water potentials can be measured with a precision of +/- 1 bar, or better.

Leveraging electrokinetics for the active control of dendritic fullerene-1 release across a nanochannel membrane

NASA Astrophysics Data System (ADS)

Bruno, Giacomo; Geninatti, Thomas; Hood, R. Lyle; Fine, Daniel; Scorrano, Giovanni; Schmulen, Jeffrey; Hosali, Sharath; Ferrari, Mauro; Grattoni, Alessandro

2015-03-01

General adoption of advanced treatment protocols such as chronotherapy will hinge on progress in drug delivery technologies that provide precise temporal control of therapeutic release. Such innovation is also crucial to future medicine approaches such as telemedicine. Here we present a nanofluidic membrane technology capable of achieving active and tunable control of molecular transport through nanofluidic channels. Control was achieved through application of an electric field between two platinum electrodes positioned on either surface of a 5.7 nm nanochannel membrane designed for zero-order drug delivery. Two electrode configurations were tested: laser-cut foils and electron beam deposited thin-films, configurations capable of operating at low voltage (<=1.5 V), and power (100 nW). Temporal, reproducible tuning and interruption of dendritic fullerene 1 (DF-1) transport was demonstrated over multi-day release experiments. Conductance tests showed limiting currents in the low applied potential range, implying ionic concentration polarization (ICP) at the interface between the membrane's micro- and nanochannels, even in concentrated solutions (<=1 M NaCl). The ability of this nanotechnology platform to facilitate controlled delivery of molecules and particles has broad applicability to next-generation therapeutics for numerous pathologies, including autoimmune diseases, circadian dysfunction, pain, and stress, among others.General adoption of advanced treatment protocols such as chronotherapy will hinge on progress in drug delivery technologies that provide precise temporal control of therapeutic release. Such innovation is also crucial to future medicine approaches such as telemedicine. Here we present a nanofluidic membrane technology capable of achieving active and tunable control of molecular transport through nanofluidic channels. Control was achieved through application of an electric field between two platinum electrodes positioned on either surface of a 5.7 nm nanochannel membrane designed for zero-order drug delivery. Two electrode configurations were tested: laser-cut foils and electron beam deposited thin-films, configurations capable of operating at low voltage (<=1.5 V), and power (100 nW). Temporal, reproducible tuning and interruption of dendritic fullerene 1 (DF-1) transport was demonstrated over multi-day release experiments. Conductance tests showed limiting currents in the low applied potential range, implying ionic concentration polarization (ICP) at the interface between the membrane's micro- and nanochannels, even in concentrated solutions (<=1 M NaCl). The ability of this nanotechnology platform to facilitate controlled delivery of molecules and particles has broad applicability to next-generation therapeutics for numerous pathologies, including autoimmune diseases, circadian dysfunction, pain, and stress, among others. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06209d

Detailed in situ laser calibration of the infrared imaging video bolometer for the JT-60U tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parchamy, H.; Peterson, B. J.; Konoshima, S.

2006-10-15

The infrared imaging video bolometer (IRVB) in JT-60U includes a single graphite-coated gold foil with an effective area of 9x7 cm{sup 2} and a thickness of 2.5 {mu}m. The thermal images of the foil resulting from the plasma radiation are provided by an IR camera. The calibration technique of the IRVB gives confidence in the absolute levels of the measured values of the plasma radiation. The in situ calibration is carried out in order to obtain local foil properties such as the thermal diffusivity {kappa} and the product of the thermal conductivity k and the thickness t{sub f} of themore » foil. These quantities are necessary for solving the two-dimensional heat diffusion equation of the foil which is used in the experiments. These parameters are determined by comparing the measured temperature profiles (for kt{sub f}) and their decays (for {kappa}) with the corresponding results of a finite element model using the measured HeNe laser power profile as a known radiation power source. The infrared camera (Indigo/Omega) is calibrated by fitting the temperature rise of a heated plate to the resulting camera data using the Stefan-Boltzmann law.« less

Alpha particle induced reactions on natCr up to 39 MeV: Experimental cross-sections, comparison with theoretical calculations and thick target yields for medically relevant 52gFe production

NASA Astrophysics Data System (ADS)

Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.

2015-08-01

Thin natCr targets were obtained by electroplating, using 23.75 μm Cu foils as backings. In five stacked foil irradiations, followed by high resolution gamma spectroscopy, the cross sections for production of 52gFe, 49,51cumCr, 52cum,54,56cumMn and 48cumV in Cr and 61Cu,68Ga in Cu were measured up to 39 MeV incident α-particle energy. Reduced uncertainty is obtained by simultaneous remeasurement of the natCu(α,x)67,66Ga monitor reactions over the whole energy range. Comparisons with the scarce literature values and results from the TENDL-2013 on-line library, based on the theoretical code family TALYS-1.6, were made. A discussion of the production routes for 52gFe with achievable yields and contamination rates was made.

Scaled experiments of explosions in cavities

DOE PAGES

Grun, J.; Cranch, G. A.; Lunsford, R.; ...

2016-05-11

Consequences of an explosion inside an air-filled cavity under the earth's surface are partly duplicated in a laboratory experiment on spatial scales 1000 smaller. The experiment measures shock pressures coupled into a block of material by an explosion inside a gas-filled cavity therein. The explosion is generated by suddenly heating a thin foil that is located near the cavity center with a short laser pulse, which turns the foil into expanding plasma, most of whose energy drives a blast wave in the cavity gas. Variables in the experiment are the cavity radius and explosion energy. Measurements and GEODYN code simulationsmore » show that shock pressuresmeasured in the block exhibit a weak dependence on scaled cavity radius up to ~25 m/kt 1/3, above which they decrease rapidly. Possible mechanisms giving rise to this behavior are described. As a result, the applicability of this work to validating codes used to simulate full-scale cavityexplosions is discussed.« less

Heating, Hydrodynamics, and Radiation From a Laser Heated Non-LTE High-Z Target

NASA Astrophysics Data System (ADS)

Gray, William; Foord, M. E.; Schneider, M. B.; Barrios, M. A.; Brown, G. V.; Heeter, R. F.; Jarrott, L. C.; Liedahl, D. A.; Marley, E. V.; Mauche, C. W.; Widmann, K.

2016-10-01

We present 2D R-z simulations that model the hydrodynamics and x-ray output of a laser heated, tamped foil, using the rad-hydro code LASNEX. The foil consists of a thin (2400 A) cylindrical disk of iron/vanadium/gold that is embedded in a thicker Be tamper. The simulations utilize a non-LTE detailed configuration (DCA) model, which generates the emission spectra. Simulated pinhole images are compared with data, finding qualitative agreement with the time-history of the face-on emission profiles, and exhibiting an interesting reduction in emission size over a few ns time period. Furthermore, we find that the simulations recover similar burn through times in both the target and Be tamper as measured by a time-dependent filtered x-ray detector (DANTE). Additional results and characterization of the experimental plasma will be presented. This work performed under the auspices of U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Printed silver nanowire antennas with low signal loss at high-frequency radio

NASA Astrophysics Data System (ADS)

Komoda, Natsuki; Nogi, Masaya; Suganuma, Katsuaki; Kohno, Kazuo; Akiyama, Yutaka; Otsuka, Kanji

2012-05-01

Silver nanowires are printable and conductive, and are believed to be promising materials in the field of printed electronics. However, the resistivity of silver nanowire printed lines is higher than that of metallic particles or flakes even when sintered at high temperatures of 100-400 °C. Therefore, their applications have been limited to the replacement of transparent electrodes made from high-resistivity materials, such as doped metallic oxides, conductive polymers, carbon nanotubes, or graphenes. Here we report that using printed silver nanowire lines, signal losses obtained in the high-frequency radio were lower than those obtained using etched copper foil antennas, because their surfaces were much smoother than those of etched copper foil antennas. This was the case even though the resistivity of silver nanowire lines was 43-71 μΩ cm, which is much higher than that of etched copper foil (2 μΩ cm). When printed silver nanowire antennas were heated at 100 °C, they achieved signal losses that were much lower than those of silver paste antennas comprising microparticles, nanoparticles, and flakes. Furthermore, using a low temperature process, we succeeded in remotely controlling a commercialized radio-controlled car by transmitting a 2.45 GHz signal via a silver nanowire antenna printed on a polyethylene terephthalate film.Silver nanowires are printable and conductive, and are believed to be promising materials in the field of printed electronics. However, the resistivity of silver nanowire printed lines is higher than that of metallic particles or flakes even when sintered at high temperatures of 100-400 °C. Therefore, their applications have been limited to the replacement of transparent electrodes made from high-resistivity materials, such as doped metallic oxides, conductive polymers, carbon nanotubes, or graphenes. Here we report that using printed silver nanowire lines, signal losses obtained in the high-frequency radio were lower than those obtained using etched copper foil antennas, because their surfaces were much smoother than those of etched copper foil antennas. This was the case even though the resistivity of silver nanowire lines was 43-71 μΩ cm, which is much higher than that of etched copper foil (2 μΩ cm). When printed silver nanowire antennas were heated at 100 °C, they achieved signal losses that were much lower than those of silver paste antennas comprising microparticles, nanoparticles, and flakes. Furthermore, using a low temperature process, we succeeded in remotely controlling a commercialized radio-controlled car by transmitting a 2.45 GHz signal via a silver nanowire antenna printed on a polyethylene terephthalate film. Electronic supplementary information (ESI) available: Operation of R/C car with a silver nanowire monopole antenna. See DOI: 10.1039/c2nr30485f

Coupling of PZT Thin Films with Bimetallic Strip Heat Engines for Thermal Energy Harvesting.

PubMed

Boughaleb, Jihane; Arnaud, Arthur; Guiffard, Benoit; Guyomar, Daniel; Seveno, Raynald; Monfray, Stéphane; Skotnicki, Thomas; Cottinet, Pierre-Jean

2018-06-06

A thermal energy harvester based on a double transduction mechanism and which converts thermal energy into electrical energy by means of piezoelectric membranes and bimetals, has previously been developed and widely presented in the literature In such a device, the thermo-mechanical conversion is ensured by a bimetal whereas the electro-mechanical conversion is generated by a piezoelectric ceramic. However, it has been shown that only 19% of the mechanical energy delivered by the bimetal during its snap is converted into electrical energy. To extract more energy from the bimetallic strip and to increase the transduction efficiency, a new way to couple piezoelectric materials with bimetals has thus been explored through direct deposition of piezoelectric layers on bimetals. This paper consequently presents an alternative way to harvest heat, based on piezoelectric bimetallic strip heat engines and presents a proof of concept of such a system. In this light, different PZT (Lead zirconate titanate) thin films were synthesized directly on aluminium foils and were attached to the bimetals using conductive epoxy. The fabrication process of each sample is presented herein as well as the experimental tests carried out on the devices. Throughout this study, different thicknesses of the piezoelectric layers and substrates were tested to determine the most powerful configuration. Finally, the study also gives some guidelines for future improvements of piezoelectric bimetals.

Formation and properties of hyaluronan/nano Ag and hyaluronan-lecithin/nano Ag films.

PubMed

Khachatryan, Gohar; Khachatryan, Karen; Grzyb, Jacek; Fiedorowicz, Maciej

2016-10-20

A facile and environmentally friendly method of the preparation of silver nanoparticles embedded in hyaluronan (Hyal/Ag) and hyaluronan-lecithin (Hyal-L/Ag) matrix was developed. Thin, elastic foils were prepared from gels by an in situ synthesis of Ag in an aqueous solution of sodium hyaluronate (Hyal), using aq. d-(+)-xylose solution as a reducing agent. The gels were applied to a clean, smooth, defatted Teflon surface and left for drying in the air. The dry foils were stored in a closed container. UV-vis spectroscopy, transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectra confirmed formation of about 10nm ball-shaped Ag nanoparticles situated within the polysaccharide template. Thermal properties of the composites were characterized involving differential scanning calorimetry (DSC) and thermogravimetric (TGA) analyses, whereas molecular weights of polysaccharide chains of the matrix were estimated with the size exclusion chromatography coupled with multiangle laser light scattering and refractometric detectors (HPSEC-MALLS-RI). An increase in the molecular weight of the hyaluronate after generation of Ag nanoparticles was observed. The foils showed specific properties. The study confirmed that silver nanoparticles can be successfully prepared with environmentally friendly method, using hyaluronan as a stabilizing template. Hyaluronan and hyaluronan-lecithin matrices provide nanocrystals uniform in size and shape. The composites demonstrated a bacteriostatic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production and Performance of the InFOCmicronS 20-40 keV Graded Multilayer Mirror

NASA Technical Reports Server (NTRS)

Berendse, F.; Owens, S. M.; Serlemitsos, P. J.; Tueller, J.; Chan, K.-W.; Soong, Y.; Krimm, H.; Baumgartner, W. H.; Tamura, K.; Okajima, T.;

Investigation of hexagonal boron nitride as an atomically thin corrosion passivation coating in aqueous solution.

PubMed

Zhang, Jing; Yang, Yingchao; Lou, Jun

2016-09-09

Hexagonal boron nitride (h-BN) atomic layers were utilized as a passivation coating in this study. A large-area continuous h-BN thin film was grown on nickel foil using a chemical vapor deposition method and then transferred onto sputtered copper as a corrosion passivation coating. The corrosion passivation performance in a Na2SO4 solution of bare and coated copper was investigated by electrochemical methods including cyclic voltammetry (CV), Tafel polarization and electrochemical impedance spectroscopy (EIS). CV and Tafel analysis indicate that the h-BN coating could effectively suppress the anodic dissolution of copper. The EIS fitting result suggests that defects are the dominant leakage source on h-BN films, and improved anti-corrosion performances could be achieved by further passivating these defects.

Design and Operation of a Calorimeter for Advanced Multilayer Insulation Testing

NASA Technical Reports Server (NTRS)

Chato, David J.; Johnson, Wesley L.; Van Dresar, Neil

2016-01-01

A calorimeter has been constructed to accurately measure insulation performance with a nominal 90K outer boundary and a 20K inner boundary. Unique features of this design include use of mechanical cryocoolers instead of cryogens and measurement of the heat load with a calibrated heat conduction rod. The calorimeter is operational and has completed its first test series. The initial test series was designed to look for differences in performance between a single layer of aluminum foil and a sheet of double aluminized Mylar (DAM). Although it has been speculated that the aluminum foil would perform better, since the aluminum coating on the Mylar might not be thick enough to stop the transmission of long wave length infrared radiation, our testing showed a higher heat load for the aluminum foil than the DAM. The aluminum foil showed a heat load of 132 mW at an 87 K outer temperature and 152 mW at a 107K outer temperature, whereas the DAM showed a heat load of 66 mW at an 88 K outer temperature and 81 mW at 108 K.

Design and Operation of a Calorimeter for Advanced Multilayer Insulation Testing

NASA Technical Reports Server (NTRS)

Chato, David; Johnson, Wesley; Dresar, Neil Van

2016-01-01

A calorimeter has been constructed to accurately measure insulation performance with a nominal 90K cold outer boundary and a 20K inner boundary. Unique features of this design include use of mechanical cryocoolers instead cryogens and measurement of the heat load with a calibrated rod to serve as a conduction path. The calorimeter is operational and has completed its first test series. The initial test series was designed to look for differences in performance between a single layer of aluminum foil and a sheet of double aluminized mylar (DAM). Although it has been speculated that the aluminum foil would perform better, since the mylar coating might not thick enough to stop the transmission of long wave length infrared radiation, our testing showed a higher heat load for the aluminum foil than the DAM. The aluminum foil showed a heat load of 132 mW at an 87 K outer temperature and 152 mW at a 107K outer temperature. Whereas the DAM showed a heat load of 66 mW at an 88 K outer temperature and 81 mW at 108 K.

Multi-junction Thin-film Solar Cells on Flexible Substrates for Space Power

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Smith, Mark; Scofield, John H.; Dickman, John E.; Lush, Gregory B.; Morel, Donald L.; Ferekides, Christos; Dhere, Neelkanth G.

2002-01-01

The ultimate objective of the thin-film program at NASA GRC is development of a 20 percent AM0 thin-film device technology with high power/weight ratio. Several approaches are outlined to improve overall device efficiency and power/weight ratio. One approach involves the use of very lightweight flexible substrates such as polyimides (i.e., Kapton(Trademark)) or metal foil. Also, a compound semiconductor tandem device structure that can meet this objective is proposed and simulated using Analysis of Microelectronic and Photonic Structures (AMPS). AMPS modeling of current devices in tandem format indicate that AM0 efficiencies near 20 percent can be achieved. And with improvements in materials, efficiencies approaching 25 percent are achievable. Several important technical issues need to be resolved to realize these complex devices: development of a wide bandgap material with good electronic properties, development of transparent contacts, and targeting a 2-terminal device structure (with more complicated processing and tunnel junction) or 4-terminal device. Recent progress in the NASA GRC program is outlined.

Feasibility demonstration for electroplating ultra-thin polyimide film. [fabricating film for space erectable structures

NASA Technical Reports Server (NTRS)

Schneier, R.; Braswell, T. V.; Vaughn, R. W.

1978-01-01

The effect of electrodeposition variables on film thickness was investigated using a dilute polyimide solution as a bath into which aluminum (as foil or as a vapor deposited coating) was immersed. The electrodeposited film was dried for 2 hours at 93 C (primarily to remove solvent) and cured for 18 hours at 186 C. Infrared studies indicate that imide formation (curing) occurs at 149 C under vacuum. From a conceptual viewpoint, satisfactory film metallized on one side can be obtained by this method. The cured ultra thin polyimide film exhibits properties equivalent to those of commercial film, and the surface appearance of the strippable polyimide film compares favorably with that of a sample of commercial film of thicker gauge. The feasibility of manufacturing approximately one million sq m of ultra thin film capable of being joined to fabricate an 800 m by 9 800 m square from starting material 0.5 to 1 m wide for space erectable structures was demonstrated.

Ca-48 targets - Home and abroad!

NASA Astrophysics Data System (ADS)

Greene, John P.; Carpenter, Michael; Janssens, Robert V. F.

2018-05-01

Using the method of reduction/distillation, high-purity films of robust and ductile calcium metal were prepared for use as targets in nuclear physics experiments. These targets, however, are extremely air-sensitive and procedures must be developed for their handling and use without exposure to the air. In most instances, the thin 48Ca target is used on a carrier foil (backing) and a thin covering film of similar material is employed to further reduce re-oxidation. Un-backed metallic targets are rarely produced due to these concerns. In addition, the low natural abundance of the isotope 48Ca provided an increased incentive for the best efficiencies available in their preparation. Here, we describe the preparation of 48Ca targets employing a gold backing and thin gold cover for use at home, Argonne National Laboratory (ANL), as well as abroad, at Osaka University. For the overseas shipments, much care and preparation were necessary to ensure good targets and safe arrival to the experimental facilities.

Strong thin membrane structure. [solar sails

NASA Technical Reports Server (NTRS)

Frazer, R. E. (Inventor)

1979-01-01

A continuous process is described for producing strong lightweight structures for use as solar sails for spacecraft propulsion by radiation pressure. A thin reflective coating, such as aluminum, is applied to a rotating cylinder. A nylon mesh, applied over the aluminum coating, is then coated with a polymerizing material such as a para-xylylene monomer gas to polymerize as a film bound to the mesh and the aluminum. An emissivity increasing material such as chromium or silicon monoxide is applied to the polymer film to disperse such material colloidally into the growing polymer film, or to the final polymer film. The resulting membrane structure is then removed from the cylinder. Alternately, the membrane structure can be formed by etching a substrate in the form of an organic film such as a polymide, or a metal foil, to remove material from the substrate and reduce its thickness. A thin reflective coating (aluminum) is applied on one side of the substrate, and an emissivity increasing coating is applied on the reverse side of the substrate.

Tunable Gas Permeability of Polymer-Clay Nano Brick Wall Thin Film Assemblies

NASA Astrophysics Data System (ADS)

Gamboa, Daniel; Priolo, Morgan; Grunlan, Jaime

2010-03-01

Thin films of anionic natural montmorrilonite (MMT) clay and cationic polyethylenimine (PEI) have been produced by alternately dipping a plastic substrate into dilute aqueous mixtures containing each ingredient. After 40 polymer-clay layers have been deposited, the resulting transparent film exhibits an oxygen transmission rate (OTR) below 0.35 cm^3/m^2 . day when the pH of PEI solution is 10. This low permeability is due to a brick wall nanostructure comprised of completely exfoliated clay bricks in polymeric mortar. This brick wall creates an extremely tortuous path at thicknesses below 250 nm and clay concentration above 80 wt%. A 70-bilayer PEI-MMT assembly has an undetectable OTR (< 0.005 cm^3/m^2 . day), which equates to a permeability below SiOx when multiplied by its film thickness of 231 nm. With optical transparency greater than 86% and the ability to be microwaved, these thin film composites are good candidates for flexible electronics packaging and foil replacement for food.

Proton-Induced X-Ray Emission Analysis of Crematorium Emissions

NASA Astrophysics Data System (ADS)

Ali, Salina; Nadareski, Benjamin; Yoskowitz, Joshua; Labrake, Scott; Vineyard, Michael

2014-09-01

There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. Union College Department of Physics and Astronomy.

Actinide Foil Production for MPACT Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beller, Denis

Sensitive fast-neutron detectors are required for use in lead slowing down spectrometry (LSDS), an active interrogation technique for used nuclear fuel assay for Materials Protection, Accounting, and Controls Technologies (MPACT). During the past several years UNLV sponsored a research project at RPI to investigate LSDS; began development of fission chamber detectors for use in LSDS experiments in collaboration with INL, LANL, and Oregon State U.; and participated in a LSDS experiment at LANL. In the LSDS technique, research has demonstrated that these fission chamber detectors must be sensitive to fission energy neutrons but insensitive to thermal-energy neutrons. Because most systemsmore » are highly sensitive to large thermal neutron populations due to the well-known large thermal cross section of 235U, even a miniscule amount of this isotope in a fission chamber will overwhelm the small population of higher-energy neutrons. Thus, fast-fission chamber detectors must be fabricated with highly depleted uranium (DU) or ultra-pure thorium (Th), which is about half as efficient as DU. Previous research conducted at RPI demonstrated that the required purity of DU for assay of used nuclear fuel using LSDS is less than 4 ppm 235U, material that until recently was not available in the U.S. In 2009 the PI purchased 3 grams of ultra-depleted uranium (uDU, 99.99998% 238U with just 0.2 ± 0.1 ppm 235U) from VNIIEF in Sarov, Russia. We received the material in the form of U3O8 powder in August of 2009, and verified its purity and depletion in a FY10 MPACT collaboration project. In addition, chemical processing for use in FC R&D was initiated, fission chamber detectors and a scanning alpha-particle spectrometer were developed, and foils were used in a preliminary LSDS experiment at a LANL/LANSCE in Sept. of 2010. The as-received U3O8 powder must be chemically processed to convert it to another chemical form while maintaining its purity, which then must be used to electro-deposit U or UO2 in extremely thin layers (1 to 2 mg/cm2) on various media such as films, foils, or discs. After many months of investigation and trials in FY10 and 11, UNLV researchers developed a new method to produce pure UO2 deposits on foils using a unique approach, which has never been demonstrated, that involves dissolution of U3O8 directly into room temperature ionic liquid (RTIL) followed by electrodeposition from the RTIL-uDU solution (Th deposition from RTIL had been previously demonstrated). The high-purity dissolution of the U3O8 permits the use of RTIL solutions for deposition of U on metal foils in layers without introducing contamination. In FY10 and early FY11 a natural U surrogate for the uDU was used to investigate this and other techniques. In this research project UNLV will deposit directly from RTIL to produce uDU and Th foils devoid of possible contaminants. After these layers have been deposited, they will be examined for purity and uniformity. UNLV will complete the development and demonstration of the RTIL technology/ methodology to prepare uDU and Th samples for use in constructing fast-neutron detectors. Although this material was purchased for use in research using fast-fission chamber detectors for active inspection techniques for MPACT, it could also contribute to R&D for other applications, such as cross section measurements or neutron spectroscopy for national security« less

Effects of laser power density and initial grain size in laser shock punching of pure copper foil

NASA Astrophysics Data System (ADS)

Zheng, Chao; Zhang, Xiu; Zhang, Yiliang; Ji, Zhong; Luan, Yiguo; Song, Libin

2018-06-01

The effects of laser power density and initial grain size on forming quality of holes in laser shock punching process were investigated in the present study. Three different initial grain sizes as well as three levels of laser power densities were provided, and then laser shock punching experiments of T2 copper foil were conducted. Based upon the experimental results, the characteristics of shape accuracy, fracture surface morphology and microstructures of punched holes were examined. It is revealed that the initial grain size has a noticeable effect on forming quality of holes punched by laser shock. The shape accuracy of punched holes degrades with the increase of grain size. As the laser power density is enhanced, the shape accuracy can be improved except for the case in which the ratio of foil thickness to initial grain size is approximately equal to 1. Compared with the fracture surface morphology in the quasistatic loading conditions, the fracture surface after laser shock can be divided into three zones including rollover, shearing and burr. The distribution of the above three zones strongly relates with the initial grain size. When the laser power density is enhanced, the shearing depth is not increased, but even diminishes in some cases. There is no obvious change of microstructures with the enhancement of laser power density. However, while the initial grain size is close to the foil thickness, single-crystal shear deformation may occur, suggesting that the ratio of foil thickness to initial grain size has an important impact on deformation behavior of metal foil in laser shock punching process.

Neutron Spectrum Measurements from Irradiations at NCERC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackman, Kevin Richard; Mosby, Michelle A.; Bredeweg, Todd Allen

2015-04-15

Several irradiations have been conducted on assemblies (COMET/ZEUS and Flattop) at the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS). Configurations of the assemblies and irradiated materials changed between experiments. Different metallic foils were analyzed using the radioactivation method by gamma-ray spectrometry to understand/characterize the neutron spectra. Results of MCNP calculations are shown. It was concluded that MCNP simulated spectra agree with experimental measurements, with the caveats that some data are limited by statistics at low-energies and some activation foils have low activities.

Refractive Secondary Solar Concentrator Demonstrated High-Temperature Operation

NASA Technical Reports Server (NTRS)

Wong, Wayne A.

2002-01-01

Space applications that utilize solar thermal energy--such as electric power conversion systems, thermal propulsion systems, and furnaces--require highly efficient solar concentration systems. The NASA Glenn Research Center is developing the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, such as inflatable thin films, the refractive secondary concentrator enables very high system concentration ratios and very high temperatures. Last year, Glenn successfully demonstrated a secondary concentrator throughput efficiency of 87 percent, with a projected efficiency of 93 percent using an antireflective coating. Building on this achievement, Glenn recently successfully demonstrated high-temperature operation of the secondary concentrator when it was used to heat a rhenium receiver to 2330 F. The high-temperature demonstration of the concentrator was conducted in Glenn's 68-ft long Tank 6 thermal vacuum facility equipped with a solar simulator. The facility has a rigid panel primary concentrator that was used to concentrate the light from the solar simulator onto the refractive secondary concentrator. NASA Marshall Space Flight Center provided a rhenium cavity, part of a solar thermal propulsion engine, to serve as the high-temperature receiver. The prototype refractive secondary concentrator, measuring 3.5 in. in diameter and 11.2 in. long, is made of single-crystal sapphire. A water-cooled splash shield absorbs spillage light outside of the 3.5-in. concentrator aperture. Multilayer foil insulation composed of tungsten, molybdenum, and niobium is used to minimize heat loss from the hightemperature receiver. A liquid-cooled canister calorimeter is used to measure the heat loss through the multilayer foil insulation.

Application of Optical Imaging Techniques for Quantification of pH and O2 Dynamicsin Porous Media

NASA Astrophysics Data System (ADS)

Li, B.; Seliman, A. F.; Pales, A. R.; Liang, W.; Sams, A.; Darnault, C. J. G.; DeVol, T. A.

2016-12-01

Understanding the spatial and temporal distribution of physical and chemical parameters (e.g. pH, O2) is imperative to characterize the behavior of contaminants in a natural environment. The objectives of this research are to calibrate pH and O2 sensor foils, to develop a dual pH/O2 sensor foil, and to apply them into flow and transport experiments, in order to understand the physical and chemical parameters that control contaminant fate and transport in an unsaturated sandy porous medium. In addition, demonstration of a sensor foil that quantifies aqueous uranium concentration will be presented. Optical imaging techniques will be conducted with 2D tanks to investigate the influence of microbial exudates and plant roots on pH and O2 parameters and radionuclides transport. As a non-invasive method, the optical imaging technique utilizes optical chemical sensor films and either a digital camera or a spectrometer to capture the changes with high temporal and spatial resolutions. Sensor foils are made for different parameters by applying dyes to generate favorable fluorescence that is proportional to the parameter of interest. Preliminary results suggested that this method could detect pH ranging from 4.5 to 7.5. The result from uranium foil test with different concentrations in the range of 2 to 8 ppm indicated that a higher concentration of uranium resulted in a greater color intensity.

TH-CD-201-01: BEST IN PHYSICS (THERAPY): Assessment of Thin-Film CdTe as An Effective Detector for Microdosimety at Gold-Tissue Interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paudel, N; University of Toledo Medical Center, Toledo, OH; Shvydka, D

Purpose: Presence of interfaces between high and low atomic number materials, often encountered in diagnostic imaging and radiation therapy, leads to radiation dose perturbation. This phenomenon is characterized by a very narrow region of sharp dose enhancement at the interface. The rapid fall-off of the dose enhancement over a very short distance from the interface makes the experimental dosimetry nontrivial. We use an in-house-built inexpensive thin-film Cadmium Telluride (CdTe) photodetector to study this effect at the gold-tissue interface and verify our experimental results with Monte Carlo (MC) modeling. Methods: Three micron thick CdTe photodetectors were fabricated in our lab. One,more » ten or one hundred micron thick gold foils placed in a tissue-equivalent-phantom were irradiated with a clinical Ir-192 high dose rate source and current measured with a CdTe detector in each case was compared against the current measured for all uniform tissue-equivalent phantom. Percentage signal enhancement (PSE) due to each gold foil was compared against MC modeled percentage dose enhancement (PDE), obtained from the geometry mimicking the experimental setup. Results: The experiment based PSEs due to 1, 10, and 100 micron thick gold foils at the closest measured distance of measurement (12.5 micron) from the interface were 42.6 ± 10.8, 137.0 ± 11.9 and 203.0 ± 15.4 respectively. The corresponding MC modeled PDEs were 38.1 ± 1, 164 ± 1 and 249 ± 1 respectively. The experimental and MC modeled values showed a closer agreement at the larger distances from the interface. Conclusion: The dose enhancement near the gold-tissue interface was measured using an in-house-built high-resolution CdTe-based photodetector and validated with MC simulations. A close agreement of the experimental results with the corresponding MC modeled results shows that CdTe detector can be utilized for mapping interface dose distribution encountered in the application of ionizing radiation.« less

Gadolinium-148 and other spallation production cross section measurements for accelerator target facilities

NASA Astrophysics Data System (ADS)

Kelley, Karen Corzine

At the Los Alamos Neutron Science Center accelerator complex, protons are accelerated to 800 MeV and directed to two tungsten targets, Target 4 at the Weapons Neutron Research facility and the 1L target at the Lujan Center. The Department of Energy requires hazard classification analyses to be performed on these targets and places limits on certain radionuclide inventories in the targets to avoid characterizing the facilities as "nuclear facilities." Gadolinium-148 is a radionuclide created from the spallation of tungsten. Allowed isotopic inventories are particularly low for this isotope because it is an alpha-particle emitter with a 75-year half-life. The activity level of Gadolinium-148 is low, but it encompasses almost two-thirds of the total dose burden for the two tungsten targets based on present yield estimates. From a hazard classification standpoint, this severely limits the lifetime of these tungsten targets. The cross section is not well-established experimentally and this is the motivation for measuring the Gadolinium-148 production cross section from tungsten. In a series of experiments at the Weapons Neutron Research facility, Gadolinium-148 production was measured for 600- and 800-MeV protons on tungsten, tantalum, and gold. These experiments used 3 mum thin tungsten, tantalum, and gold foils and 10 mum thin aluminum activation foils. In addition, spallation yields were determined for many short-lived and long-lived spallation products with these foils using gamma and alpha spectroscopy and compared with predictions of the Los Alamos National Laboratory codes CEM2k+GEM2 and MCNPX. The cumulative Gadolinium-148 production cross section measured from tantalum, tungsten, and gold for incident 600-MeV protons were 15.2 +/- 4.0, 8.31 +/- 0.92, and 0.591 +/- 0.155, respectively. The average production cross sections measured at 800 MeV were 28.6 +/- 3.5, 19.4 +/- 1.8, and 3.69 +/- 0.50 for tantalum, tungsten, and gold, respectively. These cumulative measurements compared best with Bertini and were within a factor of two to three of CEM2k+GEM2.

SU-E-T-310: Micro-Dosimetry Study of the Radiation Dose Enhancement at the Gold-Tissue Interface for Nanoparticle-Aided Radiation Therapy.

PubMed

Paudel, N; Shvydka, D; Parsai, E

2012-06-01

Gold nanoparticles (AuNP) have been proposed to be utilized for local dose enhancement in radiation therapy. Due to a very sharp spatial fall-off of the effect, the dosimetry associated with such an approach is difficult to implement in a direct measurement. This study is aimed at establishing a micro-dosimetry technique for experimental verification of dose enhancement in the vicinity of gold-tissue interface. The spatial distribution of the dose enhancement near the gold-tissue interface is modeled with Monte Carlo (MC) package MCNP5 in a 1-dimentional approach of a thin gold slab placed in an ICRU-4 component tissue phantom. The model is replicating the experiment, where the dose enhancement due to gold foils having thicknesses of 1, 10, and 100μm and areas of 12.5×25mm 2 are placed at a short distance from clinical HDR brachytherapy (Ir-192) source. The measurements are carried out with a thin-film CdTe-based photodetector, having thickness <10μm, allowing for high spatial resolution at progressively increasing distances from the foil. Our MC simulation results indicate that for Ir-192 energy spectrum the dose enhancement region extends over ∼1 mm distance from the foil, changing from several hundred at the interface to just a few percent. The trend in the measured dose enhancement closely follows the results obtained from MC simulations. AuNP's have been established as promising candidates for dose enhancement in nanoparticle-aided radiation therapy, particularly, in the energy range relevant to brachytherapy applications. Most researchers study the dose enhancement with MC simulations, or experimental approaches involving biological systems, where achievable dose enhancements are difficult to quantify. Successful development of micro-dosimetry approaches will pave a way for direct assessment of the dose in experiments on biological models, shedding some light on apparent discrepancy between physical dose enhancement and biological effect established in studies of AuNP-aided radiation therapy. No conflict of interest. © 2012 American Association of Physicists in Medicine.

Beam position monitor

DOEpatents

Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

2003-07-22

An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

Microstructure and Texture Evolution During Hot Pack Rolling of Nickel-Base Superalloys to Thin Sheet and Foil (Preprint)

DTIC Science & Technology

2011-03-01

quenching . The y’ solvus temperature (Ty’) was found to be -1150°C for alloy 5A and -1220°C for alloy 5C based on isothermal heat treatments performed in...an inert argon atmosphere followed by water quenching . Similar to conventional practices for superalloys, supersolvus hot working (at 1225°C) was...approximately five times larger than that shown in Figure 8 to provide a statistically relevant estimate, only 35 pet. of the grains in this sample were within

Triple-material stress-strain resistivity gage

DOEpatents

Stout, R.B.

1987-05-19

A triple material piezoresistive gage provides multi-component elastic stress or strain measurements. Thin foils of three piezoresistive materials, e.g., ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grind or other grind arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated form the resistivity measurements. 4 figs.

Triple-material stress-strain resistivity gage

DOEpatents

Stout, R.B.

1988-05-17

A triple material piezoresistive gage provides multi-component elastic stress measurements is disclosed. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements. 4 figs.

Triple-material stress-strain resistivity gage

DOEpatents

Stout, Ray B.

1988-01-01

A triple material piezoresistive gage provides multi-component elastic stress or measurements. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements.

Composite magnetorheological elastomers as dielectrics for plane capacitors: Effects of magnetic field intensity

NASA Astrophysics Data System (ADS)

Balasoiu, Maria; Bica, Ioan

The fabrication of composite magnetorheological elastomers (MRECs) based on silicone rubber, carbonyl iron microparticles (10% vol.) and polyurethane elastomer doped with 0%, 10% and 20% volume concentration TiO2 microparticles is presented. The obtained MRECs have the shape of thin foils and are used as dielectric materials for manufacturing plane capacitors. Using the plane capacitor method and expression of capacitance as a function of magnetic field intensity, combined with linear elasticity theory, the static magnetoelastic model of the composite is obtained and analyzed.

Laser-based ion sources for medical applications

NASA Astrophysics Data System (ADS)

Bychenkov, V. Yu.; Brantov, A. V.

2015-10-01

Interaction of relativistic short laser pulses with thin foils is studied by using 3D PIC simulations in the context of ICAN's "dream laser". It is shown that such a laser will make it possible to accelerate protons and deuterons to multi-MeV energies with a current density of 100 A/cm2. The laser-triggered hadron beams may trigger nuclear reactions of interest for nuclear medicine and pharmacy. As an example, the yields C-11 for PET, of Tc-99m for SPECT, and neutrons for therapy have been analyzed.

Development of Flexible, Free-Standing, Thin Films for Additive Manufacturing and Localized Energy Generation

DTIC Science & Technology

2015-08-10

stainless steel foil substrates that were 50 microns thick. The coatings were then placed in an oven at 60oC for 24 hours to evaporate the solvent. After...drying, the coatings were cooled at room temperature in a fume hood for 24 hours. The free standing film is photographed in Figure 2. The film was cut...composition were examined and flame speeds were measured. A glass slide with the sample strip attached was placed on a steel block housed in a

MASS SPECTROMETER

DOEpatents

White, F.A.

1960-08-23

A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

Electron transport in solid targets and in the active mixture of a CO2 laser amplifier

NASA Astrophysics Data System (ADS)

Galkowski, A.

The paper examines the use of the NIKE code for the Monte Carlo computation of the deposited energy profile and other characteristics of the absorption process of an electron beam in a solid target and the spatial distribution of primary ionization in the active mixture of a CO2 laser amplifier. The problem is considered in connection with the generation of intense electron beams and the acceleration of thin metal foils, as well as in connection with the electric discharge pumping of a CO2 laser amplifier.

Study on structural recovery of graphite irradiated with swift heavy ions at high temperature

NASA Astrophysics Data System (ADS)

Pellemoine, F.; Avilov, M.; Bender, M.; Ewing, R. C.; Fernandes, S.; Lang, M.; Li, W. X.; Mittig, W.; Schein, M.; Severin, D.; Tomut, M.; Trautmann, C.; Zhang, F. X.

2015-12-01

Thin graphite foils bombarded with an intense high-energy (8.6 MeV/u) gold beam reaching fluences up to 1 × 1015 ions/cm2 lead to swelling and electrical resistivity changes. As shown earlier, these effects are diminished with increasing irradiation temperature. The work reported here extends the investigation of beam induced changes of these samples by structural analysis using synchrotron X-ray diffraction and transmission electron microscope. A nearly complete recovery from swelling at irradiation temperatures above about 1500 °C is identified.

Hostile environments and high temperature measurements; Proceedings of the Conference, Kansas City, MO, Nov. 6-8, 1989

NASA Astrophysics Data System (ADS)

Topics presented include the identification of stagnant region in a fluidized bed combustor, high sensitivity objective grating speckle, an X-ray beam method for displacement and strain distributions using the moire method, and high-temperature deformation of a Ti-alloy composite under complex loading. Also addressed are a hybrid procedure for dynamic characterization of ceramics at elevated temperature, thermo-structural measurements in a SiC coated carbon-carbon hypersonic glide vehicle, and recent experience with elevated-temperature foil strain gages with application to thin-gage materials.

Development towards a fast ion loss detector for the reversed field pinch.

PubMed

Bonofiglo, P J; Anderson, J K; Almagri, A F; Kim, J; Clark, J; Capecchi, W; Sears, S H; Egedal, J

2016-11-01

A fast ion loss detector has been constructed and implemented on the Madison Symmetric Torus (MST) to investigate energetic ion losses and transport due to energetic particle and MHD instabilities. The detector discriminates particle orbits solely on pitch and consists of two thin-foil, particle collecting plates that are symmetric with respect to the device aperture. One plate collects fast ion signal, while the second aids in the minimization of background and noise effects. Initial measurements are reported along with suggestions for the next design phase of the detector.

Foil Electron Multiplier

DOEpatents

Funsten, Herbert O.; Baldonado, Juan R.; Dors, Eric E.; Harper, Ronnie W.; Skoug, Ruth M.

2006-03-28

An apparatus for electron multiplication by transmission that is designed with at least one foil having a front side for receiving incident particles and a back side for transmitting secondary electrons that are produced from the incident particles transiting through the foil. The foil thickness enables the incident particles to travel through the foil and continue on to an anode or to a next foil in series with the first foil. The foil, or foils, and anode are contained within a supporting structure that is attached within an evacuated enclosure. An electrical power supply is connected to the foil, or foils, and the anode to provide an electrical field gradient effective to accelerate negatively charged incident particles and the generated secondary electrons through the foil, or foils, to the anode for collection.

Comparison of experimental proton-induced fluorescence spectra for a selection of thin high-Z samples with Geant4 Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Incerti, S.; Barberet, Ph.; Dévès, G.; Michelet, C.; Francis, Z.; Ivantchenko, V.; Mantero, A.; El Bitar, Z.; Bernal, M. A.; Tran, H. N.; Karamitros, M.; Seznec, H.

2015-09-01

The general purpose Geant4 Monte Carlo simulation toolkit is able to simulate radiative and non-radiative atomic de-excitation processes such as fluorescence and Auger electron emission, occurring after interaction of incident ionising radiation with target atomic electrons. In this paper, we evaluate the Geant4 modelling capability for the simulation of fluorescence spectra induced by 1.5 MeV proton irradiation of thin high-Z foils (Fe, GdF3, Pt, Au) with potential interest for nanotechnologies and life sciences. Simulation results are compared to measurements performed at the Centre d'Etudes Nucléaires de Bordeaux-Gradignan AIFIRA nanobeam line irradiation facility in France. Simulation and experimental conditions are described and the influence of Geant4 electromagnetic physics models is discussed.

Flapping foil power generator performance enhanced with a spring-connected tail

NASA Astrophysics Data System (ADS)

Liu, Zhengliang; Tian, Fang-Bao; Young, John; Lai, Joseph C. S.

2017-12-01

The flexibility effects on the performance of a flapping foil power generator are numerically studied by using the immersed boundary-lattice Boltzmann method at a Reynolds number of 1100. The flapping foil system consists of a rigid NACA0015 foil undergoing harmonic pitch and plunge motions and a passively actuated flat plate pinned to the trailing edge of the rigid foil. The flexibility is modeled by a torsional spring model at the conjuncture of the rigid foil and the tail. Here, a parametric study on mass density and natural frequency is conducted under the optimum kinematic condition of the rigid system identified from the literature and numerical simulations made for reduced frequency f* = 0.04-0.24 and pitch amplitude θ0 = 40°-90°. Four typical cases are discussed in detail by considering time histories of hydrodynamic loads and tail deformations under the optimal and non-optimal kinematic conditions. Results show that under the rigid-system optimal kinematic condition, a tail with appropriate mass density (μ = 0.60) and resonant frequency ( fr*=1.18 ) can improve the maximum efficiency by 7.24% accompanied by an increase of 6.63% in power compared to those of a rigid foil with a rigid tail. This is because the deflection of the tail reduces the low pressure region on the pressure surface (i.e., the lower surface during the upstroke or the upper surface during the downstroke) caused by the leading edge vortex after the stroke reversal, resulting in a higher efficiency. At high flapping frequencies, a spring-connected tail ( fr*=0.13 ) eliminates the large spike in the moment observed in high stiffness cases, reducing the power required for the pitch motion, resulting in 117% improvement in efficiency over that with a rigid tail at a reduced frequency of 0.24.

Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Som S.; Desjarlais, Andre Omer; Atchley, Jerald Allen

Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearlymore » flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.« less

Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

DOE PAGES

Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; ...

2015-11-19

In this study, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ~600 kA with ~200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. As amore » result, this technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.« less

Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

NASA Astrophysics Data System (ADS)

Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

2015-11-01

In this work, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ˜600 kA with ˜200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. This technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.

In this study, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ~600 kA with ~200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. As amore » result, this technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.« less

Copper foil provides uniform heat sink path

NASA Technical Reports Server (NTRS)

Phillips, I. E., Jr.; Schreihans, F. A.

1966-01-01

Thermal path prevents voids and discontinuities which make heat sinks in electronic equipment inefficient. The thermal path combines the high thermal conductivity of copper with the resiliency of silicone rubber.

A New Electrochemical Approach for the Synthesis of Copper-Graphene Nanocomposite Foils with High Hardness

PubMed Central

Pavithra, Chokkakula L. P.; Sarada, Bulusu V.; Rajulapati, Koteswararao V.; Rao, Tata N.; Sundararajan, G.

2014-01-01

Graphene has proved its significant role as a reinforcement material in improving the strength of polymers as well as metal matrix composites due to its excellent mechanical properties. In addition, graphene is also shown to block dislocation motion in a nanolayered metal-graphene composites resulting in ultra high strength. In the present paper, we demonstrate the synthesis of very hard Cu-Graphene composite foils by a simple, scalable and economical pulse reverse electrodeposition method with a well designed pulse profile. Optimization of pulse parameters and current density resulted in composite foils with well dispersed graphene, exhibiting a high hardness of ~2.5 GPa and an increased elastic modulus of ~137 GPa while exhibiting an electrical conductivity comparable to that of pure Cu. The pulse parameters are designed in such a way to have finer grain size of Cu matrix as well as uniform dispersion of graphene throughout the matrix, contributing to high hardness and modulus. Annealing of these nanocomposite foils at 300°C, neither causes grain growth of the Cu matrix nor deteriorates the mechanical properties, indicating the role of graphene as an excellent reinforcement material as well as a grain growth inhibitor. PMID:24514043

CFD Analysis of the Oscillating Flow within a Stirling Engine with an Additively Manufactured Foil Type Regenerator

NASA Astrophysics Data System (ADS)

Qiu, Songgang; Solomon, Laura

2017-11-01

The simplistic design, fuel independence, and robustness of Stirling convertors makes them the ideal choice for use in solar power and combined heat and power (CHP) applications. A lack of moving parts and the use of novel flexure bearings allows free-piston type Stirling engines to run in excess of ten years without degradation or maintenance. The key component to their overall efficiency is the regenerator. While a foil type regenerator outperforms a sintered random fiber regenerator, limitation in manufacturing and keeping uniform spacing between the foils has limited their overall use. However, with the advent of additive manufacturing, a robust foil type regenerator can be cheaply manufactured without traditional limitations. Currently, a CFD analysis of the oscillating internal flow within the novel design was conducted to evaluate the flow loses within the system. Particularly the pressure drop across the regenerator in comparison to a traditionally used random fiber regenerator. Additionally, the heat transfer and flow over the tubular heater hear was evaluated. The results of the investigation will be used to optimize the operation of the next generation of additively manufactured Stirling convertors. This research was supported by ARPA-E and West Virginia University.

Achromobacter xylosoxidans as a new microorganism strain colonizing high-density polyethylene as a key step to its biodegradation.

PubMed

Kowalczyk, Anna; Chyc, Marek; Ryszka, Przemysław; Latowski, Dariusz

2016-06-01

This study presents results of research on isolation new bacteria strain Achromobacter xylosoxidans able to effect on the structure of high-density polyethylene (HDPE), polymer resistant to degradation in environment. New strain of A. xylosoxidans PE-1 was isolated from the soil and identified by analysis of the 16S ribosome subunit coding sequences. The substance to be degraded was HDPE in the form of thin foil films. The foil samples were analyzed with Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) as well as scanning electron microscope (SEM), and the results revealed degradation of chemical structure of HDPE. About 9 % loss of weight was also detected as a result of A. xylosoxidans PE-1 effect on HDPE foil. On the basis of comparative spectral analysis of the raw material before the bacteria treatment and the spectrum from a spectra database, it was assumed that the HDPE was the only source of carbon and energy for the microorganisms. No fillers or other additives used in the plastic processing were observed in HDPE before experiments. This is the first communication showing that A. xylosoxidans is able to modify chemical structure of HDPE, what was observed both on FTIR, in mass reduction of HDPE and SEM analysis. We also observed quite good growth of the bacteria also when the HDPE was the sole carbon source in the medium. These results prove that A. xylosoxidans is an organism worth applying in future HDPE biodegradation studies.

Thin film rechargeable electrodes based on conductive blends of nanostructured olivine LiFePO4 and sucrose derived nanocarbons for lithium ion batteries.

PubMed

Praveen, P; Jyothsna, U; Nair, Priya; Ravi, Soumya; Balakrishnan, A; Subramanian, K R V; Nair, A Sreekumaran; Nair, V Shantikumar; Sivakumar, N

2013-08-01

The present study provides the first reports of a novel approach of electrophoretic co-deposition technique by which titanium foils are coated with LiFePO4-carbon nanocomposites synthesized by sol gel route and processed into high-surface area cathodes for lithium ion batteries. The study elucidates how sucrose additions as carbon source can affect the surface morphology and the redox reaction behaviors underlying these cathodes and thereby enhance the battery performance. The phase and morphological analysis were done using XRD and XPS where the LiFePO4 formed was confirmed to be a high purity orthorhombic system. From the analysis of the relevant electrochemical parameters using cyclic voltammetry and electrochemical impedance spectroscopy, a 20% increment and 90% decrement in capacity and impedance values were observed respectively. The composite electrodes also exhibited a specific capacity of 130 mA h/g. It has been shown that cathodes based on such composite systems can allow significant room for improvement in the cycling performance at the electrode/electrolyte interface.

1.2 MW peak power, all-solid-state picosecond laser with a microchip laser seed and a high gain single-passing bounce geometry amplifier

NASA Astrophysics Data System (ADS)

Wang, Chunhua; Shen, Lifeng; Zhao, Zhiliang; Liu, Bin; Jiang, Hongbo; Chen, Jun; Liu, Chong

2016-11-01

A semiconductor saturable absorber mirror (SESAM) based passively Q-switched microchip Nd:YVO4 seed laser with pulse duration of 90 ps at repetition rate of 100 kHz is amplified by single-passing a Nd:YVO4 bounce amplifier with varying seed input power from 20 μW to 10 mW. The liquid pure metal greasy thermally conductive material is used to replace the traditional thin indium foil as the thermal contact material for better heat load transfer of the Nd:YVO4 bounce amplifier. Temperature distribution at the pump surface is measured by an infrared imager to compare with the numerically simulated results. A highest single-passing output power of 11.3 W is obtained for 10 mW averaged seed power, achieving a pulse peak power of ~1.25 MW and pulse energy of ~113 μJ. The beam quality is well preserved with M2 ≤1.25. The simple configuration of this bounce laser amplifier made the system flexible, robust and cost-effective, showing attractive potential for further applications.

Optimization of pulsed laser welding process parameters in order to attain minimum underfill and undercut defects in thin 316L stainless steel foils

NASA Astrophysics Data System (ADS)

Pakmanesh, M. R.; Shamanian, M.

2018-02-01

In this study, the optimization of pulsed Nd:YAG laser welding parameters was done on the lap-joint of a 316L stainless steel foil with the aim of reducing weld defects through response surface methodology. For this purpose, the effects of peak power, pulse-duration, and frequency were investigated. The most important weld defects seen in this method include underfill and undercut. By presenting a second-order polynomial, the above-mentioned statistical method was managed to be well employed to balance the welding parameters. The results showed that underfill increased with the increased power and reduced frequency, it first increased and then decreased with the increased pulse-duration; and the most important parameter affecting it was the power, whose effect was 65%. The undercut increased with the increased power, pulse-duration, and frequency; and the most important parameter affecting it was the power, whose effect was 64%. Finally, by superimposing different responses, improved conditions were presented to attain a weld with no defects.

Enhanced Low-Enriched Uranium Fuel Element for the Advanced Test Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, M. A.; DeHart, M. D.; Morrell, S. R.

2015-03-01

Under the current US Department of Energy (DOE) policy and planning scenario, the Advanced Test Reactor (ATR) and its associated critical facility (ATRC) will be reconfigured to operate on low-enriched uranium (LEU) fuel. This effort has produced a conceptual design for an Enhanced LEU Fuel (ELF) element. This fuel features monolithic U-10Mo fuel foils and aluminum cladding separated by a thin zirconium barrier. As with previous iterations of the ELF design, radial power peaking is managed using different U-10Mo foil thicknesses in different plates of the element. The lead fuel element design, ELF Mk1A, features only three fuel meat thicknesses,more » a reduction from the previous iterations meant to simplify manufacturing. Evaluation of the ELF Mk1A fuel design against reactor performance requirements is ongoing, as are investigations of the impact of manufacturing uncertainty on safety margins. The element design has been evaluated in what are expected to be the most demanding design basis accident scenarios and has met all initial thermal-hydraulic criteria.« less

Unsteady lift and thrust of a 2D flapping thin airfoil in the presence of additional leading edge vortices

NASA Astrophysics Data System (ADS)

Alaminos-Quesada, Javier; Fernandez-Feria, Ramon

2017-11-01

The effect of leading-edge vortices (LEVs) on the lift, thrust and moment of a two-dimensional heaving and pitching foil is analyzed from the unsteady, linear potential theory. General expressions taking into account the effect of unsteady point vortices interacting with the oscillatory trailing wake are first derived. Then, simplified expressions for the initial stages of the growing LEV on each half-stroke are used to obtain analytical closed expressions for the main contribution of these vortices to the lift, thrust and moment. It is found that, within the linear potential framework and the Brown-Michael model, the LEV contributes to the aerodynamic forces and moment only for combined pitching and heaving motions of the foil, being a relevant contribution for sufficiently large values of the product of the reduced frequency and the amplitude of the heaving and/or pitching motions. The results are compared with available experimental data and numerical simulations. Supported by the Ministerio de Economia y Competitividad of Spain Grants No. DPI2013-40479-P and DPI2016-76151-C2-1-R.

Bundled and densified carbon nanotubes (CNT) fabrics as flexible ultra-light weight Li-ion battery anode current collectors

NASA Astrophysics Data System (ADS)

Yehezkel, Shani; Auinat, Mahmud; Sezin, Nina; Starosvetsky, David; Ein-Eli, Yair

2016-04-01

Carbon nanotubes (CNT) fabrics were studied and evaluated as anode current collectors, replacing the traditional copper foil current collector in Li-ion batteries. Glavanostatic measurements reveal high values of irreversible capacities (as high as 28%), resulted mainly from the formation of the solid electrolyte interphase (SEI) layer at the CNT fabric surface. Various pre-treatments to the CNT fabric prior to active anode material loading have shown that the lowest irreversible capacity is achieved by immersing and washing the CNT fabric with iso-propanol (IPA), which dramatically modified the fabric surface. Additionally, the use of very thin CNT fabrics (5 μm) results in a substantial irreversible capacity minimization. A combination of IPA rinse action and utilization of the thinnest CNT fabric provides the lowest irreversible capacity of 13%. The paper describes innovative and rather simple techniques towards a complete implementation of CNT fabric as an anode current collector in Li-ion batteries, instead of the relatively heavy and expensive copper foil, enabling an improvement in the gravimetric and volumetric energy densities of such advanced batteries.

Comparison of two surface temperature measurement using thermocouples and infrared camera

NASA Astrophysics Data System (ADS)

Michalski, Dariusz; Strąk, Kinga; Piasecka, Magdalena

This paper compares two methods applied to measure surface temperatures at an experimental setup designed to analyse flow boiling heat transfer. The temperature measurements were performed in two parallel rectangular minichannels, both 1.7 mm deep, 16 mm wide and 180 mm long. The heating element for the fluid flowing in each minichannel was a thin foil made of Haynes-230. The two measurement methods employed to determine the surface temperature of the foil were: the contact method, which involved mounting thermocouples at several points in one minichannel, and the contactless method to study the other minichannel, where the results were provided with an infrared camera. Calculations were necessary to compare the temperature results. Two sets of measurement data obtained for different values of the heat flux were analysed using the basic statistical methods, the method error and the method accuracy. The experimental error and the method accuracy were taken into account. The comparative analysis showed that although the values and distributions of the surface temperatures obtained with the two methods were similar but both methods had certain limitations.

Slumped glass optics with interfacing ribs for high angular resolution x-ray astronomy: a progress report

NASA Astrophysics Data System (ADS)

Civitani, M.; Basso, S.; Brizzolari, C.; Ghigo, M.; Pareschi, G.; Salmaso, B.; Spiga, D.; Vecchi, G.; Breunig, E.; Burwitz, V.; Hartner, G. D.; Menz, B.

2015-09-01

The Slumped Glass Optics technology, developed at INAF/OAB since a few years, is becoming a competitive solution for the realization of the future X-ray telescopes with a very large collecting area, as e.g. the proposed Athena, with more than 2 m2 effective area at 1 keV and with a high angular resolution (5'' HEW). The developed technique is based on modular elements, named X-ray Optical Units (XOUs), made of several layers of thin foils of glass, previously formed by direct hot slumping in cylindrical configuration, and then stacked in a Wolter-I configuration, through interfacing ribs. The achievable global angular resolution of the optics relies on the surface shape accuracy of the slumped foils, on the smoothness of the mirror surfaces and on the correct integration and co-alignment of the mirror segments achieved with a dedicated Integration Machine (IMA). In this paper we provide an update of the project development, reporting on the last results achieved. In particular, we will present the results obtained with full illumination X-ray tests for the last developed prototypes.

Predicting neutron damage using TEM with in situ ion irradiation and computer modeling

NASA Astrophysics Data System (ADS)

Kirk, Marquis A.; Li, Meimei; Xu, Donghua; Wirth, Brian D.

2018-01-01

We have constructed a computer model of irradiation defect production closely coordinated with TEM and in situ ion irradiation of Molybdenum at 80 °C over a range of dose, dose rate and foil thickness. We have reexamined our previous ion irradiation data to assign appropriate error and uncertainty based on more recent work. The spatially dependent cascade cluster dynamics model is updated with recent Molecular Dynamics results for cascades in Mo. After a careful assignment of both ion and neutron irradiation dose values in dpa, TEM data are compared for both ion and neutron irradiated Mo from the same source material. Using the computer model of defect formation and evolution based on the in situ ion irradiation of thin foils, the defect microstructure, consisting of densities and sizes of dislocation loops, is predicted for neutron irradiation of bulk material at 80 °C and compared with experiment. Reasonable agreement between model prediction and experimental data demonstrates a promising direction in understanding and predicting neutron damage using a closely coordinated program of in situ ion irradiation experiment and computer simulation.

Rapid Synthesis of Thin and Long Mo17O47 Nanowire-Arrays in an Oxygen Deficient Flame

PubMed Central

Allen, Patrick; Cai, Lili; Zhou, Lite; Zhao, Chenqi; Rao, Pratap M.

2016-01-01

Mo17O47 nanowire-arrays are promising active materials and electrically-conductive supports for batteries and other devices. While high surface area resulting from long, thin, densely packed nanowires generally leads to improved performance in a wide variety of applications, the Mo17O47 nanowire-arrays synthesized previously by electrically-heated chemical vapor deposition under vacuum conditions were relatively thick and short. Here, we demonstrate a method to grow significantly thinner and longer, densely packed, high-purity Mo17O47 nanowire-arrays with diameters of 20–60 nm and lengths of 4–6 μm on metal foil substrates using rapid atmospheric flame vapor deposition without any chamber or walls. The atmospheric pressure and 1000 °C evaporation temperature resulted in smaller diameters, longer lengths and order-of-magnitude faster growth rate than previously demonstrated. As explained by kinetic and thermodynamic calculations, the selective synthesis of high-purity Mo17O47 nanowires is achieved due to low oxygen partial pressure in the flame products as a result of the high ratio of fuel to oxidizer supplied to the flame, which enables the correct ratio of MoO2 and MoO3 vapor concentrations for the growth of Mo17O47. This flame synthesis method is therefore a promising route for the growth of composition-controlled one-dimensional metal oxide nanomaterials for many applications. PMID:27271194

Inkjet-Printed Lithium-Sulfur Microcathodes for All-Printed, Integrated Nanomanufacturing.

PubMed

Milroy, Craig A; Jang, Seonpil; Fujimori, Toshihiko; Dodabalapur, Ananth; Manthiram, Arumugam

2017-03-01

Improved thin-film microbatteries are needed to provide appropriate energy-storage options to power the multitude of devices that will bring the proposed "Internet of Things" network to fruition (e.g., active radio-frequency identification tags and microcontrollers for wearable and implantable devices). Although impressive efforts have been made to improve the energy density of 3D microbatteries, they have all used low energy-density lithium-ion chemistries, which present a fundamental barrier to miniaturization. In addition, they require complicated microfabrication processes that hinder cost-competitiveness. Here, inkjet-printed lithium-sulfur (Li-S) cathodes for integrated nanomanufacturing are reported. Single-wall carbon nanotubes infused with electronically conductive straight-chain sulfur (S@SWNT) are adopted as an integrated current-collector/active-material composite, and inkjet printing as a top-down approach to achieve thin-film shape control over printed electrode dimensions is used. The novel Li-S cathodes may be directly printed on traditional microelectronic semicoductor substrates (e.g., SiO 2 ) or on flexible aluminum foil. Profilometry indicates that these microelectrodes are less than 10 µm thick, while cyclic voltammetry analyses show that the S@SWNT possesses pseudocapacitive characteristics and corroborates a previous study suggesting the S@SWNT discharge via a purely solid-state mechanism. The printed electrodes produce ≈800 mAh g -1 S initially and ≈700 mAh g -1 after 100 charge/discharge cycles at C/2 rate. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.