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Sample records for thin carbon foils

  1. Production of thin carbon stripper foils using heated-substrates in a cathodic arc deposition system

    International Nuclear Information System (INIS)

    Merchant, A.R.; Lobanov, N.; Elliman, R.G.; Ophel, T.R.; Rode, A.; Weisser, D.C.; Turkentine, R.B.

    1998-01-01

    The lifetime of carbon stripper foil can have a marked impact on the successful running of a beam line. Standard techniques for production of carbon stripper foils include evaporation of carbon (ec) and laser-pulsed ablation (Ipa). Recent work by a using Ipa has been successful in substantially increasing the lifetime of a very thin foil. The suspected mechanism for the increased lifetime of the foil is that the amorphous carbon foil is density-matched to that of graphite (around 2.26g/cc). In this work, we attempt to reproduce this result by producing carbon stripper foils with a mass-density similar to graphite using a cathodic arc deposition system. The cathodic arc is well known for the production of tetrahedral amorphous carbon: a high density, high stress form of carbon with over 90% sp 3 -like bonds; to reduce the density of the carbon and promote more graphitic structure, a high bias was initially attempted but this proved unsuccessful. Another method is to use a heated-substrate holder to reduce compressive stress within the deposited film. The performance of the density-matched carbon stripper foils and the implications for future production of high-quality carbon stripper foils in our laboratory will be discussed. (authors)

  2. Monte Carlo simulation of positron induced secondary electrons in thin carbon foils

    International Nuclear Information System (INIS)

    Cai, L H; Yang, B; Ling, C C; Beling, C D; Fung, S

    2011-01-01

    Emission of secondary electrons induced by the passage of low energy positrons through thin carbon foils was studied by the Monte Carlo method. The positron and electron elastic cross sections were calculated by partial wave analysis. The inelastic positron-valence-electron was described by the energy loss function obtained from dielectric theory. The positron-core-electron interaction was modelled by the Gryzinski's excitation function. Positron transport inside the carbon foil was simulated in detail. Secondary electrons created by positrons and high energy secondary electrons through inelastic interactions were tracked through the foil. The positron transmission coefficient and secondary electron yielded in forward and backward geometry are calculated and dependences on positron energy and carbon foil thickness are discussed.

  3. Determination of low-energy ion-induced electron yields from thin carbon foils

    International Nuclear Information System (INIS)

    Allegrini, Frederic; Wimmer-Schweingruber, Robert F.; Wurz, Peter; Bochsler, Peter

    2003-01-01

    Ion beams crossing thin carbon foils can cause electron emission from the entrance and exit surface. Thin carbon foils are used in various types of time-of-flight (TOF) mass spectrometers to produce start pulses for TOF measurements. The yield of emitted electrons depends, among other parameters, on the energy of the incoming ion and its mass, and it has been experimentally determined for a few projectile elements. The electron emission yield is of great importance for deriving abundance ratios of elements and isotopes in space plasmas using TOF mass spectrometers. We have developed a detector for measuring ion-induced electron yields, and we have extended the electron yield measurements for oxygen to energies relevant for solar wind research. We also present first measurements of the carbon foil electron emission yield for argon and iron in the solar wind energy range

  4. Simulation of the molecular recombination yield for swift H2+ ions through thin carbon foils

    International Nuclear Information System (INIS)

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

    2003-01-01

    We have calculated the recombination yield for swift H 2 + molecular ions at the exit of thin amorphous carbon foils, as a function of the dwell time and incident energy. Our results are based on a detailed simulation of the motion through the target of the H 2 + molecular ion (before dissociation takes place) and its constituent fragments (after dissociation), including the following effects: Coulomb repulsion, nuclear scattering, electron capture and loss, as well as self-retarding and wake forces, which provide the relative distance and velocity of the dissociated fragments at the foil exit. The recombination of an H 2 + ion at the exit of the foil depends on the interproton separation and internal energy of the dissociated fragments, and on their probability to capture an electron. Comparison of our results with the available experimental data shows a good agreement

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

    Science.gov (United States)

    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.

  6. The effects of deoxidation practice on the quality of thin foil low-carbon steel

    Directory of Open Access Journals (Sweden)

    Pereira Batista R.

    2017-01-01

    Full Text Available In converter steelmaking of AISI 1006 steel for thin foil products, two tapping practices are used with respect to deoxidation: silicon and manganese additions during tapping and aluminum deoxidation after complete tapping (“semikilled practice” and aluminum deoxidation during tapping, “fully killed practice”. There is a perception that the semikilled practice may be more economical and result in the same quality as the fully killed practice. In this work, the effects of the tapping practice on steel quality and cost variables were evaluated for thin foils of AISI 1006 steel. Oxygen and aluminum content, aluminum and ferro-alloy yield, the type of alumina inclusions formed, and the quality of the steel during thin foil rolling were evaluated and compared. It is shown that the fully killed practice leads to less reoxidation from slag, lower soluble oxygen, and lower total oxygen at the caster as well as better morphology of the remaining alumina inclusions than the semi-killed practice. Thus, the higher quality of the steel produced via the fully killed tapping deoxidation practice when compared with semi-killed tapping is demonstrated. It is also shown that a complete cost evaluation favors this practice in the case of products rolled for tin foil production.

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

    CERN Document Server

    Stolarz, A

    2002-01-01

    Large area self-supporting carbon foils in the thickness of range of 8-22 mu g/cm sup 2 , coated with approximately 4 mu g/cm sup 2 MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm sup 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stolarz, Anna E-mail: anna@slcj.uw.edu.pl; Maier-Komor, Peter

    2002-03-11

    Large area self-supporting carbon foils in the thickness of range of 8-22 {mu}g/cm{sup 2}, coated with approximately 4 {mu}g/cm{sup 2} MgO have been prepared by e-gun evaporation. They were mounted on frames with apertures of 130 cm{sup 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.

  9. Radiation lifetimes and failure mechanisms of carbon stripper foils

    International Nuclear Information System (INIS)

    Auble, R.L.

    1981-01-01

    Measurements of lifetimes of thin carbon foils under heavy-ion irradiation are compiled and recent advances in stripper foil technology are reviewed. The impact of recent foil lifetime improvements, many by more than an order of magnitude, on heavy-ion electrostatic accelerators is discussed. Foil inhomogeneities, particularly those caused by sputtering are suggested to be a prime factor in usable foil lifetimes

  10. Densities of carbon foils

    International Nuclear Information System (INIS)

    Stoner, J.O. Jr.

    1991-01-01

    The densities of arc-evaporated carbon target foils have been measured by several methods. The density depends upon the method used to measure it; for the same surface density, values obtained by different measurement techniques may differ by fifty percent or more. The most reliable density measurements are by flotation, yielding a density of 2.01±0.03 g cm -3 , and interferometric step height with the surface density known from auxiliary measurements, yielding a density of 2.61±0.4 g cm -3 . The difference between these density values mayy be due in part to the compressive stresses that carbon films have while still on their substrates, uncertainties in the optical calibration of surface densities of carbon foils, and systematic errors in step-height measurements. Mechanical thickness measurements by micrometer caliper are unreliable due to nonplanarity of these foils. (orig.)

  11. Angular scattering of 1–50 keV ions through graphene and thin carbon foils: Potential applications for space plasma instrumentation

    International Nuclear Information System (INIS)

    Ebert, Robert W.; Allegrini, Frédéric; Fuselier, Stephen A.; Nicolaou, Georgios; Bedworth, Peter; Sinton, Steve; Trattner, Karlheinz J.

    2014-01-01

    We present experimental results for the angular scattering of ∼1–50 keV H, He, C, O, N, Ne, and Ar ions transiting through graphene foils and compare them with scattering through nominal ∼0.5 μg cm −2 carbon foils. Thin carbon foils play a critical role in time-of-flight ion mass spectrometers and energetic neutral atom sensors in space. These instruments take advantage of the charge exchange and secondary electron emission produced as ions or neutral atoms transit these foils. This interaction also produces angular scattering and energy straggling for the incident ion or neutral atom that acts to decrease the performance of a given instrument. Our results show that the angular scattering of ions through graphene is less pronounced than through the state-of-the-art 0.5 μg cm −2 carbon foils used in space-based particle detectors. At energies less than 50 keV, the scattering angle half width at half maximum, ψ 1/2 , for ∼3–5 atoms thick graphene is up to a factor of 3.5 smaller than for 0.5 μg cm −2 (∼20 atoms thick) carbon foils. Thus, graphene foils have the potential to improve the performance of space-based plasma instruments for energies below ∼50 keV

  12. Backward and forward electron emission induced by helium projectiles incident on thin carbon foils: Influence of charge changing processes

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, N. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium)]. E-mail: nipauly@ulb.ac.be; Dubus, A. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium); Roesler, M. [Karl-Pokern-Str. 12, D-12587 Berlin (Germany)

    2007-03-15

    The backward and forward electron emission yields {gamma} {sub B} and {gamma} {sub F} have been calculated by Monte Carlo simulations for helium (He{sup ++}, He{sup +} or He{sup 0}) ions incident on thin amorphous carbon foils with energies around the electronic stopping power maximum (0.2-2 MeV). Besides the direct excitation of target electrons by the incident projectile, we have taken into account the different charge changing processes (He{sup ++} {r_reversible} He{sup +} {r_reversible} He{sup 0}) undergone by the helium ion in the target. We discuss in particular the connection between the electron emission yield {gamma} and the electronic stopping power (dE/dx){sub e}. We compare our results with previously published experimental results.

  13. Fusion welding of thin metal foils

    International Nuclear Information System (INIS)

    Casey, H.

    1975-01-01

    Aspects of fusion welding of thin metal foils are reviewed and the current techniques employed at LASL to join foils are described. Techniques for fusion welding approximately 0.025-mm-thick foils of copper, aluminum, and stainless steels have been developed using both electron beam and laser welding equipment. These techniques, together with the related aspects of joint design, tooling and fixturing, joint preparation, and modifications to the commercially available welding equipment, are included in the review. (auth)

  14. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    Vidovic, Z.

    1997-06-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  15. Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

    International Nuclear Information System (INIS)

    Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

    1985-01-01

    These measurements were undertaken as a consequence of our failure early this year to accelerate Au +46 ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV 197 Au +17 from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV 197 Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs

  16. Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

    1985-01-01

    These measurements were undertaken as a consequence of our failure early this year to accelerate Au/sup +46/ ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV /sup 197/Au/sup +17/ from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV /sup 197/Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs.

  17. Secondary electron emission from a thin carbon foil induced by H+, He2+ and Li3+ at fixed velocity of 1 MeV/u

    International Nuclear Information System (INIS)

    Ogawa, H.; Sorai, K.; Amano, S.; Ishii, K.; Kaneko, T.

    2013-01-01

    The statistical distributions of the number of forward- and backward-emitted secondary electrons (SE’s) from a thin carbon foil have been measured simultaneously in coincidence with foil-transmitted H + , He 2+ and Li 3+ ions of 1 MeV/u in order to examine the forward–backward correlation of the SE emission (refer to as ‘FB correlation’ hereafter). With these projectiles, we have also measured the energy spectrum of SEs emitted from another carbon foil of similar thickness in the direction around 0° with respect to the incident beams. From the emission statistics data, it is found that both of the inclusive forward and backward SE yields divided by the square of the projectile atomic number (Z p ) decrease with increasing Z p . This trend is qualitatively consistent with previous works by other authors. On the other hand, it has been certified from the energy spectra that the yields of binary electron scale well with Z p 2 . As for the FB correlation, the forward- or backward-emitted SE yield decreases gradually with increasing the number of SEs emitted in the opposite directions. This so-called ‘negative FB correlation’ appears to be pronounced for He 2+ and Li 3+ ions compared with that for H + ions. Since low energy internal SEs do not contribute to the FB correlation, the observed Z p -dependent FB correlation seems to be consistent with the well Z p 2 -scaled production of high energy internal SEs and the decrease of the inclusive forward and backward SE yields with respect to this scaling

  18. Production and thickness determination of thin plastic scintillator foils

    International Nuclear Information System (INIS)

    Xiao, B.; Lee, S.; Hagel, K.; Haddad, F.; Li, J.; Lou, Y.; Mdeiwayeh, N.; Tezkratt, R.; Wada, R.; Utley, D.; Natowitz, J.B.

    1995-01-01

    A method of making large thin plastic scintillator foils with good uniformity is presented. The use of Fourier Transform Infrared Spectroscopy (FTIR) to test the foil uniformity and to establish an empirical thickness calibration curve is described. ((orig.))

  19. Interaction of relativistic H- ions with thin foils

    International Nuclear Information System (INIS)

    Mohagheghi, A.H.

    1990-09-01

    The response of relativistic H - ions to thin carbon foils was investigated for beam energies ranging from 226 MeV to 800 MeV. For the foil thicknesses we have studied, ranging from 15 to 300 μg/cm 2 , an appreciable fraction of the H - beam survives intact, some H - ions are stripped down to protons, and the remainder is distributed over the states of H 0 . This experiment is different from the low energy studies in that the projectile velocity is comparable to the speed of light, leading to an interaction time of typically less than a femtosecond. The present results challenge the theoretical understanding of the interaction mechanisms. An electron spectrometer was used to selectively field-ionize the Rydberg states, 9 < n < 17, at beam energies of 581 MeV and 800 MeV. The yield of low-lying states were measured by Doppler tuning a Nd:YAG laser to excite transitions to a Rydberg state which was then field-ionized and detected. A simple model is developed to fit the yield of each state as a function of foil thickness. The simple model is successful in predicting the general features of the yield data. However, the data are suggestive of a more complex structure in the yield curves. The yield of a given state depends strongly on the foil thickness, demonstrating that the excited states are formed during the passage of the ions through a foil. The optimum thickness to produce a given state increases with the principal quantum number of the state suggesting an excitation process which is at least pratially stepwise. The results of a Monte Carlo simulation are compared with the experimental data to estimate the distribution of the excited states coming out of a foil. The distributions of the excited states and their dependence on foil thickness are discussed

  20. Carbon stripper foils held in place with carbon fibers

    International Nuclear Information System (INIS)

    Jolivet, Connie S.; Miller, Shawn A.; Stoner, John O.; Ladd, Peter

    2008-01-01

    The Spallation Neutron Source (SNS) currently under construction at Oak Ridge National Laboratory, Oak Ridge, Tennessee, is planned to initially utilize carbon stripper foils having areal densities approximately 260 μg/cm 2 . The projected design requires that each foil be supported by only one fixed edge. For stability of the foil, additional support is to be provided by carbon fibers. The feasibility of manufacturing and shipping such mounted carbon foils produced by arc evaporation was studied using two prototypes. Production of the foils is described. Fibers were chosen for satisfactory mechanical strength consistent with minimal interference with the SNS beam. Mounting of the fibers, and packaging of the assemblies for shipping are described. Ten completed assemblies were shipped to SNS for further testing. Preliminary evaluation of the survivability of the foils in the SNS foil changer is described

  1. Thin foil expansion into a vacuum

    International Nuclear Information System (INIS)

    Mora, P.

    2005-01-01

    Plasma expansion into a vacuum is an old problem which has been renewed recently in various contexts: expansion of ultra-cold plasmas, cluster expansion, of dust grains, expansion of thin foils. In this presentation I will first discuss the physics of the expansion of a thin foil irradiated by an ultra-short ultra-intense laser pulse. The expansion results in the formation of high energy ions. For an infinitely steep plasma-vacuum interface the fastest ions are located in the outer part of the expansion and their velocity is given by ν m ax∼ 2 C s (In ω p it) where c s (Zk B T e /m i )''1/2 is the ion-acoustic velocity ω p i=(n e 0Ze''2/m i e 0 )''1/2 is the ion plasma frequency, n e 0 is the electron density in the unperturbed plasma, Z is the ion charge number. In the above expression, t is either the pulse duration or the effective acceleration time (in particular t∼L/2c s , where L is the width of the foil, when the electron cooling is taken into account). A salient characteristic of the expansion is the occurrence of a double layer structure and a peak of the accelerating electric field at the ion front. I will explain the origin of the peak and predict its temporal behavior. This peak has been diagnosed in recent experiments. I will also discuss the effect of a 2-temperatures electron distribution function on the expansion, showing the dominant role of the hot electron component. Finally I will discuss the occurrence of ion spikes in the expansion when the initial density profile is smooth. The ion spike is due to a wave breaking which cannot be handled in a satisfactory way by a fluid code and requires a kinetic description. A. simple collisionless particle code has been used to treat the evolution of the spike after the wave breaking and the results will be shown. (Author)

  2. Lifetimes of carbon foils deposited on etched substrates

    International Nuclear Information System (INIS)

    Stoner, J.O. Jr.; Bashkin, S.; Hartog, P.D.; Thomas, G.; Yntema, J.L.

    1981-01-01

    The methods currently in use for producing long-lived carbon foils are listed. The possible common factors which are important in making long lasting foils are a) making a strong, coherent, continuous layer, b) making a foil slack, loose, or baggy, and c) making a foil whose molecular structure minimizes shrinkage. The behavior of foils deposited on etched substrates is compared with foils deposited upon conventional microscope slides

  3. Three-dimensional thermal simulations of thin solid carbon foils for charge stripping of high current uranium ion beams at a proposed new heavy-ion linac at GSI

    Directory of Open Access Journals (Sweden)

    N. A. Tahir

    2014-04-01

    Full Text Available This paper presents an extensive numerical study of heating of thin solid carbon foils by 1.4  MeV/u uranium ion beams to explore the possibility of using such a target as a charge stripper at the proposed new Gesellschaft für Schwerionenforschung high energy heavy–ion linac. These simulations have been carried out using a sophisticated 3D computer code that accounts for physical phenomena that are important in this problem. A variety of beam and target parameters have been considered. The results suggest that within the considered parameter range, the target will be severely damaged by the beam. Thus, a carbon foil stripper does not seem to be a reliable option for the future Gesellschaft für Schwerionenforschung high energy heavy–ion linac, in particular, at FAIR design beam intensities.

  4. Electronic excitation in transmission of relativistic H- ions through thin foils

    International Nuclear Information System (INIS)

    Reinhold, C.O.; Kuerpick, P.; Burgdoerfer, J.; Yoshida, S.

    1998-01-01

    The authors describe a theoretical model to study the transmission of relativistic H - ions through thin carbon foils. The approach is based on a Monte Carlo solution of the Langevin equation describing electronic excitations of the atoms during the transport through the foil. Calculations for the subshell populations of outgoing hydrogen atoms are found to be in good agreement with recent experimental data on an absolute scale and show that there exists a propensity for populating extreme Stark states

  5. Positron annihilation lifetime spectroscopy study of Kapton thin foils

    Science.gov (United States)

    Kanda, G. S.; Ravelli, L.; Löwe, B.; Egger, W.; Keeble, D. J.

    2016-01-01

    Variable energy positron annihilation lifetime spectroscopy (VE-PALS) experiments on polyimide material Kapton are reported. Thin Kapton foils are widely used in a variety of mechanical, electronic applications. PALS provides a sensitive probe of vacancy-related defects in a wide range of materials, including open volume in polymers. Varying the positron implantation energy enables direct measurement of thin foils. Thin Kapton foils are also commonly used to enclose the positron source material in conventional PALS measurements performed with unmoderated radionuclide sources. The results of depth-profiled positron lifetime measurements on 7.6 μm and 25 μm Kapton foils are reported and determine a dominant 385(1) ps lifetime component. The absence of significant nanosecond lifetime component due to positronium formation is confirmed.

  6. Material Properties of Laser-Welded Thin Silicon Foils

    Directory of Open Access Journals (Sweden)

    M. T. Hessmann

    2013-01-01

    Full Text Available An extended monocrystalline silicon base foil offers a great opportunity to combine low-cost production with high efficiency silicon solar cells on a large scale. By overcoming the area restriction of ingot-based monocrystalline silicon wafer production, costs could be decreased to thin film solar cell range. The extended monocrystalline silicon base foil consists of several individual thin silicon wafers which are welded together. A comparison of three different approaches to weld 50 μm thin silicon foils is investigated here: (1 laser spot welding with low constant feed speed, (2 laser line welding, and (3 keyhole welding. Cross-sections are prepared and analyzed by electron backscatter diffraction (EBSD to reveal changes in the crystal structure at the welding side after laser irradiation. The treatment leads to the appearance of new grains and boundaries. The induced internal stress, using the three different laser welding processes, was investigated by micro-Raman analysis. We conclude that the keyhole welding process is the most favorable to produce thin silicon foils.

  7. The transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

    Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

    1980-01-01

    We present new results on the transmission of fast molecular ions through thin foils and propose a mechanism for the transmission process. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target. (orig.)

  8. Transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

    Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

    1979-01-01

    New results on the transmission of fast molecular ions through thin foils are presented and a mechanism for the transmission process is proposed. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target

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

    OpenAIRE

    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...

  10. Finite Element Modelling of Bends and Creases during Folding Ultra Thin Stainless Steel Foils

    NARCIS (Netherlands)

    Datta, K.; Akagi, H.; Geijselaers, Hubertus J.M.; Huetink, Han

    2003-01-01

    Finite Element Modelling of an ultra thin foil of SUS 304 stainless steel is carried out. These foils are 20 mm and below in thickness. The development of stresses and strains during folding of these foils is studied. The objective of this study is to induce qualities of paper in the foils of

  11. Hybrid-type long-lived carbon stripper foils

    International Nuclear Information System (INIS)

    Sugai, Isao; Kato, Hajime

    1989-01-01

    A new method for the preparation of hybrid-type long-lived carbon stripper foils was developed. The new procedure is based on a modification of our controlled dc arc-discharge method. The carbon foils are of the multilayer type and the layers are composed of carbon particles emitted from the electrodes in the ac arc-discharge and from the cathode in the dc arc-discharge. With this simple and powerful method long lived carbon stripper foils can be prepared with higher reliability and reproducibility than with the previous procedure. (orig.)

  12. Ablative acceleration of thin foil targets by intense proton beams

    International Nuclear Information System (INIS)

    Miyamoto, S.; Ozaki, T.; Imasaki, K.; Higaki, S.; Nakai, S.

    1981-01-01

    A focused proton beam of up to 2 x 10 10 w/cm 2 was obtained using pinch-reflex ion diode connected to Reiden IV generator. Experiments of beam target interaction have been done using thin foil targets. In this power range the interaction was explained classically. The experimental dependence of ablation pressure on proton beam intensity was obtained as P sub(a) = 3 x 10 -3 I sup(0.7) bar (I in w/cm 2 ). (author)

  13. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  14. Intense heavy ion beam-induced effects in carbon-based stripper foils

    International Nuclear Information System (INIS)

    Kupka, Katharina

    2016-08-01

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  15. Interaction of positron beams with thin silver foils and surfaces

    International Nuclear Information System (INIS)

    Rysholt Poulsen, M.

    1994-01-01

    Experimental investigations of positron interactions with solid silver and the necessary platform to analyse the data have been presented. The main objective was to study Ps formation at a Ag(100) surface. The different ingredients of the scenario, including thermalization and diffusion of positrons and emission of Ps, were analysed and quantified in whatever way appropriate. The scattering and possible thermalization were described. The parametrization of Monte-Carlo simulated implantation profiles for semi-infinite materials were presented and the applicability of such profiles to thin foils assessed. The latter was done in conjunction with an analysis of experimental data on thermalization and diffusion in 1900 Aa Ag(100) foils. The necessity for MC simulated rather than parametrized implantation profiles was argued. The velocity of thermally desorbed Ps from a Ag(100) surface at ∼800 K appeared to obey and one-dimensional Maxwell Boltzmann distribution multiplied by a velocity dependent factor. More experimental investigations are needed before firm conclusions can be made on the nature of the emission process. The velocity distribution, though, was found to be near-thermal and indicative of the sample temperature. It has been shown that positrons can be converted into Ps atoms in the transmission geometry of a thin 1900 Aa Ag(100) foil with a high efficiency. Furthermore, 61% of the emitted Ps will have a mean velocity of v z =1.2x10 5 m/sec and 39% will have a maximum kinetic energy of 1.5 eV (v z =5.1x10 5 m/sec) at a foil temperature of 800 K, all velocities that are suitable for producing a 'dense' Ps gas target. (EG) 12 refs

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

    Science.gov (United States)

    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.

  17. Beam-foil study of neon in the EUV with foils of carbon, silver and gold

    International Nuclear Information System (INIS)

    Demarest, J.A.; Watson, R.L.; Texas A and M Univ., College Station

    1988-01-01

    A beam-foil study of 40 MeV neon was conducted in the EUV with a 1-meter grazing incidence spectrometer configured with a position sensitive microchannel plate detector. A number of new lines of Ne IX, mainly from transitions to n = 3 levels, were detected in the wavelength region covering 50-350 A. Comparison of the spectra obtained using the different foils revealed that the average charge state of the neon projectiles was nearly one unit higher with carbon than with either of the two metals. Measurements of line intensities versus distance from the foils showed that cascade contributions were greatly reduced for the metals. It was also found that n = 3 states of low l were overpopulated relative to a statistical distribution, irrespective of the foil material. (orig.)

  18. Monte Carlo transport of electrons and positrons through thin foils

    International Nuclear Information System (INIS)

    Legarda, F.; Idoeta, R.

    2000-01-01

    In the different measurements made with electrons traversing matter it becomes useful the knowledge of its transmission through that medium, their paths and their angular distribution through matter so as to process and get information about the traversed medium and to improve and innovate the techniques that employ electrons, as medical applications or materials irradiation. This work presents a simulation of the transport of beams of electrons and positrons through thin foils using an analog Monte Carlo code that simulates in a detailed way every electron movement or interaction in matter. As those particles penetrate thin absorbers it has been assumed that they interact with matter only through elastic scattering, with negligible energy loss. This type of interaction has been described quite precisely because its angular form influences very much the angular distribution of electrons and positrons in matter. With this code it has been calculated the number of particles, with energies between 100 and 3000 keV, that are transmitted through different media of various thicknesses as well as its angular distribution, showing a good agreement with experimental data. The discrepancies are less than 5% for thicknesses lower than about 30% of the corresponding range in the tested material. As elastic scattering is very anisotropic, angular distributions resemble a collimated incident beam for very thin foils becoming slowly more isotropic when absorber thickness is increased. (author)

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

    International Nuclear Information System (INIS)

    Liu, Tung-Chang; Shao, Xi; Liu, Chuan-Sheng; Eliasson, Bengt; Wang, Jyhpyng; Chen, Shih-Hung

    2014-01-01

    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, a 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 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

  20. Allotropic effects on the energy loss of swift H+ and He+ ion beams through thin foils

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Abril, Isabel; Denton, Cristian D.; Heredia-Avalos, Santiago

    2006-01-01

    We have developed a theoretical treatment and a simulation code to study the energy loss of swift H + and He + ion beams interacting with thin foils of different carbon allotropes. The former is based on the dielectric formalism, and the latter combines Monte Carlo with the numerical solution of the motion equation for each projectile to describe its trajectory and interactions through the target. The capabilities of both methods are assessed by the reasonably good agreement between their predictions and the experimental results, for a wide range of projectile energies and target characteristics. Firstly, we apply the theoretical procedure to calculate the stopping cross sections for H + and He + beams in foils of different allotropic forms of carbon (such as diamond, graphite, amorphous carbon, glassy carbon and C 60 -fullerite), as a function of the projectile energy. We take into account the electronic structure of the projectile, as well as the different charge states it can acquire, the energy loss associated to the electronic capture and loss processes, the polarization of the projectile, and a realistic description of the target. On the other hand, the simulation code is used to evaluate the energy distributions of swift H + and He + ion beams when traversing several foils of the above mentioned allotropic forms of carbon, in order to analyze the influence of the chemical and physical state of the target in the projectile energy loss. These allotropic effects are found to become more important around the maximum of the stopping cross-section

  1. Method and apparatus for coating thin foil with a boron coating

    Science.gov (United States)

    Lacy, Jeffrey L.

    2018-01-16

    An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm 2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm 2 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 ∼1μg/cm 2 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 4 for the 197 Au − (∼9MeV, ∼1μA) and 63 Cu − (∼9MeV, ∼1μA) 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 sp 3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (I D /I G ) measured by the Raman spectroscopy is 0.78

  3. Development of a new foil compounded from carbon nanotubes and sputter-deposition carbon

    International Nuclear Information System (INIS)

    Hiroo Hasebe; Hironori Kuboki; Hiroki Okuno; Isao Yamane; Hiroshi Imao; Nobuhisa Fukunishi; Masayuki Kase; Osamu Kamigaito

    2014-01-01

    New carbon-nanotube-sputter-deposition-carbon (CNT-SDC) foils were developed and used in the U beam time at the RIKEN RI Beam Factory (RIBF) from October to December 2011. The lifetimes of these new foils were drastically extended, and stable, high-intensity U beams were successfully provided to users. The lifetime of the CNT-SDC foils was 2-5 C, which was 100 times longer than those of static C-foils previously used. The qualitative analysis of the CNT-SDC foils clearly showed that the CNT structure and bundles were broken by beam irradiation. In addition, it was found that CNT bundles in the CNT-SDC foil were grown after the carbon deposition procedure. This structure was considered to be the reason that the CNT-SDC foils maintain advantages of both CNT and SDC foils. (author)

  4. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  5. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l'impact de projectiles H0, H2+, H3+ d'energie de l'ordre du MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vidovic, Z

    1997-06-15

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  6. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l'impact de projectiles H0, H2+, H3+ d'energie de l'ordre du MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vidovic, Z

    1997-06-15

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  7. Electron microscope observation of single - crystalline beryllium thin foils

    International Nuclear Information System (INIS)

    Antolin, J.; Poirier, J.P.; Dupouy, J.M.

    1965-01-01

    Thin foils prepared from single crystalline beryllium simples deformed at room temperature, have been observed by transmission electron microscopy. The various deformation modes have been investigated separately, from their early stages and their characteristic dislocation configurations have been observed. Basal slip is characterized at is outset by the presence of numerous dipoles and elongated prismatic loops. More pronounced cold work leads to the formation of dislocation tangles and bundles which eventually give a cellular structure. Prismatic slip begins by the cross-slip of dislocations from the basal plane into the prismatic plane. A cellular structure is equally observed in heavily deformed samples. Sessile dislocations have been observed in twin boundaries; they are produced by reactions between slip dislocations and twin dislocations. Finally, the study of samples quenched from 1100 deg. C and annealed at 200 deg. C has shown that the observed loops lie in prismatic planes and have a Burgers vector b 1/3 . (authors) [fr

  8. Gas permeability through thin-foil x-ray filters

    Science.gov (United States)

    Tveekrem, June L.; Keski-Kuha, Ritva A.; Webb, Andrew T.

    1997-10-01

    We have measured the permeation rates of helium and water through thin-foil UV-blocking filters used in the ASTRO-E/x- ray spectrometer (XRS) instrument. In the XRS program, there is a concern that outgassed contaminants such as water could permeate through the outermost filter which will be at room temperature and freeze on the inner filters which will be at cryogenic temperatures. The filters tested consisted of approximately 1000 angstroms Al on approximately 1000 angstroms of either Lexan or polyimide. Measurements were made using a vacuum apparatus consisting essentially of two small chambers separated by the filter under test. A helium leak detector was used to measure helium permeation rates, and a residual gas analyzer (RGA) was used to detect water. Results discussed include permeation rate as a function of pressure difference across a filter, the ratio of helium permeation rate over water permeation rate, and the effect of the aluminum layer thickness on permeation.

  9. Novel technique of making thin target foil of high density material via rolling method

    Science.gov (United States)

    Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

    2018-05-01

    The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

  10. Investigation of methods to prepare carbon foils and to determine their thicknesses

    International Nuclear Information System (INIS)

    Xu Guoji; Guan Shouren; Luo Xinghua; Meng Xiangjin

    1988-01-01

    The development and study of methods to prepare carbon foils and to determine their thicknesses are described. The methods of making carbon foils consist of carbon-arc evaporation, resistance heating, electron bombardment, cracking ethylene and centrifugal precipitation. Weighing, α-particle measurement, Rutherford backscattering and spectrophotometer are used to determine the thickness of carbon foils

  11. The foil equilibration method for carbon in sodium

    Energy Technology Data Exchange (ETDEWEB)

    Borgstedt, H; Frees, G; Peric, Z [Karlsruhe Nuclear Research Center, Institute of Materials and Solid State Research, Karlsruhe (Germany)

    1980-05-01

    Among the non-metallic impurities in sodium, carbon plays an important role since at high temperatures the structural materials exposed to sodium are subject to carburization and decarburization depending on the carbon activity of the sodium. Carburization of austenitic stainless steels leads to reduction in ductility and fatigue properties whereas decarburization results in a decrease in the high temperature creep strength. A knowledge of the carbon activities in sodium will help understanding of the carbon transfer phenomena in operating sodium systems of the fast reactors, and also carbon diffusion, microstructural stability and mechanical behaviour of materials under different service conditions. An understanding of the carbon behaviour in sodium becomes difficult in view of the complexities of the different species present as elemental carbon, carbide, acetylide, carbonate, and cyanide. Carbon estimation techniques for sodium presently in use are: chemical analytical methods, on-line carbon monitors, and oil equilibration method. Various chemical methods have been developed for the estimation of different species like acetylide, cyanide, carbonate, elemental carbon, and total carbon in sodium. All these methods are time consuming and subject to various errors. The on-line monitors developed for carbon in sodium are able to give continuous indication of carbon activities and have higher sensitivity than the chemical methods. A still more simple method for the determination of carbon activities is by the foil equilibration first published by Natesan et al. Because of its simplicity like the vanadium wire equilibration for oxygen it is being used widely for the estimation of carbon activities in sodium systems. Carbon concentrations in operating sodium systems estimated by this procedure by applying solubility relation to carbon activities have yielded very low values of carbon, lower than the sensitivity limits of the chemical estimation methods. Foil

  12. The foil equilibration method for carbon in sodium

    International Nuclear Information System (INIS)

    Borgstedt, H.; Frees, G.; Peric, Z.

    1980-01-01

    Among the non-metallic impurities in sodium, carbon plays an important role since at high temperatures the structural materials exposed to sodium are subject to carburization and decarburization depending on the carbon activity of the sodium. Carburization of austenitic stainless steels leads to reduction in ductility and fatigue properties whereas decarburization results in a decrease in the high temperature creep strength. A knowledge of the carbon activities in sodium will help understanding of the carbon transfer phenomena in operating sodium systems of the fast reactors, and also carbon diffusion, microstructural stability and mechanical behaviour of materials under different service conditions. An understanding of the carbon behaviour in sodium becomes difficult in view of the complexities of the different species present as elemental carbon, carbide, acetylide, carbonate, and cyanide. Carbon estimation techniques for sodium presently in use are: chemical analytical methods, on-line carbon monitors, and oil equilibration method. Various chemical methods have been developed for the estimation of different species like acetylide, cyanide, carbonate, elemental carbon, and total carbon in sodium. All these methods are time consuming and subject to various errors. The on-line monitors developed for carbon in sodium are able to give continuous indication of carbon activities and have higher sensitivity than the chemical methods. A still more simple method for the determination of carbon activities is by the foil equilibration first published by Natesan et al. Because of its simplicity like the vanadium wire equilibration for oxygen it is being used widely for the estimation of carbon activities in sodium systems. Carbon concentrations in operating sodium systems estimated by this procedure by applying solubility relation to carbon activities have yielded very low values of carbon, lower than the sensitivity limits of the chemical estimation methods. Foil

  13. Search for Rayleigh-Taylor instability in laser irradiated layered thin foil targets

    International Nuclear Information System (INIS)

    Kilkenny, J.D.; Hares, J.D.; Rumsby, P.T.

    1980-01-01

    An experiment to measure the Rayleigh-Taylor instability at the vacuum-ablation surface of laser irradiated layered targets by time resolved x-ray spectroscopy is described. The time taken to burn through a layer of material is measured to be the same for massive targets as for thin foil accelerating targets. It is inferred that the thin foil targets might be Rayleigh-Taylor stable despite the values of γtauapproximately equal to15 calculated from classical theory. (author)

  14. INJECTION CARBON STRIPPING FOIL ISSUES IN THE SNS ACCUMULATOR RING

    International Nuclear Information System (INIS)

    BEEBE-WANG, J.; LEE, Y.Y.; RAPARIA, D.; WEI, J.

    2001-01-01

    We are reporting the results of studies on issues related to the injection stripping foil in the Spallation Neutron Source (SNS) accumulator ring. The problems related to foil heating and foil lifetime, such as current density distribution and temperature distribution in the foil, are investigated. The impact of injection errors on the beam losses at the foil is studied. The particle traversal rate and the beam losses due to scattering in the foil are summarized. Finally, SNS end-to-end simulation results of the foil-missing rate, the foil-hitting rate and the maximum foil temperature are presented

  15. Simulation of the energy spectra of original versus recombined H2+ molecular ions transmitted through thin foils

    International Nuclear Information System (INIS)

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

    2004-01-01

    This work presents the results of computer simulations for the energy spectra of original versus recombined H 2 + 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 2 + molecular ions clearly appear in the simulations, in agreement with the available experimental data. Our simulation code also differentiates the contributions due to original and to recombined H 2 + 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 2 + molecular ions transmitted through thin foils

  16. Room temperature thin foil SLIM-cut using an epoxy paste: experimental versus theoretical results

    International Nuclear Information System (INIS)

    Bellanger, Pierre; Serra, Joao; Bouchard, Pierre-Olivier; Bernacki, Marc

    2015-01-01

    The stress induced lift-off method (SLIM) -cut technique allows the detachment of thin silicon foils using a stress inducing layer. In this work, results of SLIM-cut foils obtained using an epoxy stress inducing layer at room temperature are presented. Numerical analyses were performed in order to study and ascertain the important experimental parameters. The experimental and simulation results are in good agreement. Indeed, large area (5 × 5 cm 2 ) foils were successfully detached at room temperature using an epoxy thickness of 900 μm and a curing temperature of 150 °C. Moreover, three foils (5 × 3 cm 2 ) with thickness 135, 121 and 110 μm were detached from the same monocrystalline substrate. Effective minority carrier lifetimes of 46, 25 and 20 μs were measured using quasi-steady-state photoconductance technique in these foils after iodine ethanol surface passivation. (paper)

  17. A new method for making long-lived carbon stripper foils

    International Nuclear Information System (INIS)

    Sugai, Isao; Ishii, Sabro; Hattori, Toshiyuki; Muto, Hideshi; Takahashi, Yohsuke; Kato, Hajime; Yamazaki, Kuniaki.

    1989-01-01

    We have developed a new method for preparation of long-lived carbon stripper foils, based on the modification of our 'controlled DC arc-discharge method'. The carbon foils consist of multi-layers, and carbon particles in each layer are emitted from the electrode in AC arc-discharge or from the cathode electrode in DC arc-discharge. The lifetimes of the carbon foils made by the new method are equal to or longer than those prepared by the controlled DC arc-discharge method. The new method is simple and powerful to make long-lived carbon stripper foils with higher reliability and reproducibility than the previous method. (author)

  18. Measurement of the thickness and homogeneity of thin foils by slowing down alpha particles

    International Nuclear Information System (INIS)

    Bimbot, R.; Della Negra, S.; Deprun, C.; Gardes, D.; Rivet, M.F.

    1979-01-01

    The energy loss of 8.785 MeV α particles passing through a thin foil is used to measure the foil thickness. The measurement is performed in various points of the target, the abscissa and ordinate of which are set with precision from the outside of the chamber. This gives a thickness map of the target. The working up of the data, and the use of energy loss tables are made in a standard way. The absolute uncertainty is of some percent for 100 μg/cm 2 foils. The technique has been refined to reach the same precision for 10 μg/cm 2 targets [fr

  19. An efficient fabrication of vertically aligned carbon nanotubes on flexible aluminum foils by catalyst-supported chemical vapor deposition

    International Nuclear Information System (INIS)

    Yoshikawa, Naoki; Kishi, Naoki; Sugai, Toshiki; Shinohara, Hisanori; Asari, Takuma; Hayashi, Shigeo

    2008-01-01

    An efficient and versatile growth of thin-layer carbon nanotubes on a flexible aluminum foil (for kitchen use) by catalyst-supported chemical vapor deposition is reported. The aluminum foil used in the present experiment is commercially available for kitchen use. The electron-beam vapor deposition and dip-coating have been used for preparing catalysts on the aluminum foil. Vertically aligned thin-layer CNTs with typical diameters of 2.5-6.0 nm and lengths up to 90 μm are obtained when ethanol is used in combination with Fe and Co catalyst particles at a growth temperature of around 650 deg. C under an Ar/H 2 gas flow. Thermo-gravimetric analyses together with HR-TEM observations indicate that the purity of the CNTs synthesized by the current technique is very high

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

    Energy Technology Data Exchange (ETDEWEB)

    Martini, R., E-mail: roberto.martini@imec.be [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Kepa, J.; Stesmans, A. [Department of Physics, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven (Belgium); Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Poortmans, J. [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Universiteit Hasselt, Martelarenlaan 42, B-3500 Hasselt (Belgium)

    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. 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.

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

    International Nuclear Information System (INIS)

    Martini, R.; Kepa, J.; Stesmans, A.; Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I.; Poortmans, J.

    2014-01-01

    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. 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.

  2. Quantum beats study of the 4He+ beam-carbon foil interaction

    International Nuclear Information System (INIS)

    Denis, A.; Desesquelles, J.

    1979-01-01

    Excitation cross-sections are deduced from the analysis of quantum beats in an electric field for an 4 He + (n=4) ion beam scattering through a thin carbon foil. The population distribution obtained at 1 MeV for 4S, 4P, 4D and 4F levels is in good agreement with a second-order Born approximation calculation of the electronic capture He ++ +C→He + (n=4) + C + . The alignment is found to be negative for P, D and F levels. The coherences Δl=+-1 have been measured, for amplitudes and phases [fr

  3. Microcutting and forming of thin aluminium foils for MEMS

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Mortensen, Dennis; Rombach, Pirmin

    2011-01-01

    . The relation between applied pressure and forming and cutting features has been characterized for a specific set of stamp geometries and boundary conditions. The results show that 10 μm forming features can be transferred to 4 m thick Al foils, which simultaneously can be cut into products by 25 μm wide cut...

  4. Convergent beam thickness determination of thin foil zirconium specimens

    International Nuclear Information System (INIS)

    Cann, C.D.

    1978-07-01

    The use of convergent beam patterns to determine the thickness of zirconium foils observed in the electron microscope has been investigated both theoretically and experimentally. On the basis of many-beam dynamical theory calculations, the [1012], [1013], and [1120] reflections at an accelerating voltage of 100 kV and the [1013], [1120], and [1122] reflections at 200 kV were found most suitable for convergent beam thickness determinations. Experimental convergent beam patterns were obtained in the JEOL-200B electron microscope under two different sets of conditions based on the size of the pattern desired. Computer assisted analysis of the patterns obtained gave foil thicknesses in good agreement with those determined from thickness extinction contours. (author)

  5. Optical observations of molecular dissociation in thin foils

    International Nuclear Information System (INIS)

    Berry, H.G.; Gay, T.J.; Brooks, R.L.

    1981-01-01

    We have measured the intensity and polarizations of light emitted from atomic excited states of dissociated molecular ions. Using HeH + projectiles, we have observed factors of 1-5 enhancements of the light from n=3, sup(1,3)P,D states of He I and some He II and H I emissions. Observations of Lyman alpha emission after dissociation of H 2 + and H 3 + show rapid variations in light yield for small internuclear separations at the foil surface. (author)

  6. Resonance effects of transition radiation emitted from thin foil stacks using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering; and others

    1997-03-01

    Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

  7. Gas permeability of thin polyimide foils prepared by in-situ polymerisation

    International Nuclear Information System (INIS)

    Stolarz, Anna; Varlam, Mihai; Wellum, Roger

    2008-01-01

    The entrance windows to the gas detector chambers as well as to the target containers used in high-energy and high-intensity accelerators must be as thin as possible to minimise energy losses of the particles used in astrophysics and nuclear physics studies. Because of their good physical properties, polyimide foils are often considered as suitable material for such windows, but commercially available foils, having a thickness greater than 7-8 μm (>1 mg/cm 2 ), would cause energy losses of particles significant for some nuclear reactions studied. Foils prepared by in-situ polymerisation can, however, be as thin as 0.07 μm (∼10 μg/cm 2 ). The permeability of 4 μm foils produced by in-situ polymerisation has been measured at room temperature for He and Ar. For He measurements were performed in the pressure range of 4-70 mbar and for Ar in the range of 20-140 mbar and the permeability was found to be in good agreement with the values published for the thicker commercial foils

  8. Charge state distributions for heavy ions in carbon stripper foils

    International Nuclear Information System (INIS)

    McMahan, M.A.; Lebed, R.F.; Feinberg, B.

    1989-03-01

    We have extended the database of measured charge state distributions available in the literature through measurements at the SuperHILAC using carbon stripper foils in the energy range 1.2--8.5 MeV/u. Modifying a semi-empirical model to include the effect of electronic shells, we are able to correctly predict the mean charge state to within 1/2 a charge state for 6≤Z≤92 and energies from 30 keV/u to 16 MeV/u. We have determined parameters for the widths of the distributions for each electronic shell. For distributions lying across a shell boundary, we join the two Gaussians of different widths to get an asymmetric distribution. 18 refs., 4 figs., 2 tabs

  9. All-Carbon Electrode Consisting of Carbon Nanotubes on Graphite Foil for Flexible Electrochemical Applications

    Directory of Open Access Journals (Sweden)

    Je-Hwang Ryu

    2014-03-01

    Full Text Available We demonstrate the fabrication of an all-carbon electrode by plasma-enhanced chemical vapor deposition for use in flexible electrochemical applications. The electrode is composed of vertically aligned carbon nanotubes that are grown directly on a flexible graphite foil. Being all-carbon, the simple fabrication process and the excellent electrochemical characteristics present an approach through which high-performance, highly-stable and cost-effective electrochemical applications can be achieved.

  10. Hydrodynamic simulations of light ion beam-matter interactions: ablative acceleration of thin foils

    International Nuclear Information System (INIS)

    Devore, C.R.; Gardner, J.H.; Boris, J.P.; Mosher, D.

    1984-01-01

    A one-dimensional model is used to study the hydrodynamic response of thin foils to bombardment by an intense proton beam. The beam targets are single- and multilayer planar foils of gold and polystyrene. The main conclusion is that the efficiency of conversion of incident beam energy to directed kinetic energy of the target is maximized by using a multilayer design. For beam parameters associated with the Gamble II device at the Naval Research Laboratory, the simulations yield payload velocities of over 5 cm/μs and energy conversion efficiencies of over 30%. The implications of these results for inertial confinement fusion research are discussed. (author)

  11. Carbon nanotube foils for electron stripping in tandem accelerators

    International Nuclear Information System (INIS)

    Reden, Karl von; Zhang Mei; Meigs, Martha; Sichel, Enid; Fang Shaoli; Baughman, Ray H.

    2007-01-01

    Carbon nanotube technology has rapidly advanced in recent years, making it possible to create meter-long, ∼4 cm wide films of multi-walled tubes of less than 3 μg/cm 2 areal density in a bench top open-air procedure. The physical properties of individual carbon nanotubes have been well established, equaling or surpassing electrical and thermal conductivity and mechanical strength of most other materials, graphite in particular. The handling and transport of such nanotube films, dry-mounted self-supporting on metal frames with several cm 2 of open area, is problem-free: the aerogel films having a volumetric density of about 1.5 mg/cm 3 survived the trip by car and air from Dallas to Oak Ridge without blemish. In this paper we will present the results of first tests of these nanotube films as electron stripper media in a tandem accelerator. The tests were performed in the Model 25 URC tandem accelerator of the Holifield radioactive ion beam facility (HRIBF) at Oak Ridge National Laboratory. We will discuss the performance of nanotube films in comparison with chemical vapor deposition and laser-ablated carbon foils

  12. UV-transmission and fluorescence properties of polymer thin foils for use in microlens array fabrication

    International Nuclear Information System (INIS)

    Silvano, Donati; Wei, Mao-Kuo; Cai, Jhih-Hao; Lee, Jiun-Haw

    2010-01-01

    There is a report of measurements of optical transmission and fluorescence of thin foils of polyethylene terephthalate polymer, data that are unavailable in literature to the best of our knowledge. The foils are those commonly used as substrate and lens material in microlens arrays designed for use in multi-pixel image photodetectors with the purpose of fill-factor recovery. The wavelength range covered by the measurements is 200 to 800 nm and the thickness of polyethylene terephthalate foils is 40-80 μm. It was found a UV-transmission cutoff of 320 nm for polyethylene terephthalate and 330 nm for cured epoxy on polyethylene terephthalate. Fluorescence of the samples is peaked at 385 nm and the wavelength of most effective fluorescence is 340 nm

  13. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...... in a test quadrant of the telescope structure and from ASTRO-D foils held in a simple fixture. The X-ray data is compared with laser data and other surface structure data such as STM, atomic force microscopy (AFM), TEM, and electron micrography. The data obtained at Cu K-alpha(1), (8.05 keV) from all...

  14. Polarity influence on the indentation punching of thin {111} GaAs foils at elevated temperatures

    International Nuclear Information System (INIS)

    Patriarche, G; Largeau, L; Riviere, J P; Bourhis, E Le

    2005-01-01

    Thin {111} GaAs substrates were deformed by a Vickers indenter at 350 deg. C-370 deg. C under loads ranging between 0.4 and 1.9 N. Optical microscopy and interferometry were used to observe the indented and opposite faces of the thin foils and hence to investigate the plastic flow through the samples. Attention was paid to the polarity (A or B) of the specimen surface, as GaAs is known to show a large difference between α and β dislocations mobilities. A model considering the influence of polarity is proposed to describe the material flow throughout thin samples

  15. Thin Foil Acceleration Method for Measuring the Unloading Isentropes of Shock-Compressed Matter

    International Nuclear Information System (INIS)

    Asay, J.R.; Chhabildas, L.C.; Fortov, V.E.; Kanel, G.I.; Khishchenko, K.V.; Lomonosov, I.V.; Mehlhorn, T.; Razorenov, S.V.; Utkin, A.V.

    1999-01-01

    This work has been performed as part of the search for possible ways to utilize the capabilities of laser and particle beams techniques in shock wave and equation of state physics. The peculiarity of these techniques is that we have to deal with micron-thick targets and not well reproducible incident shock wave parameters, so all measurements should be of a high resolution and be done in one shot. Besides the Hugoniots, the experimental basis for creating the equations of state includes isentropes corresponding to unloading of shock-compressed matter. Experimental isentrope data are most important in the region of vaporization. With guns or explosive facilities, the unloading isentrope is recovered from a series of experiments where the shock wave parameters in plates of standard low-impedance materials placed behind the sample are measured [1,2]. The specific internal energy and specific volume are calculated from the measured p(u) release curve which corresponds to the Riemann integral. This way is not quite suitable for experiments with beam techniques where the incident shock waves are not well reproducible. The thick foil method [3] provides a few experimental points on the isentrope in one shot. When a higher shock impedance foil is placed on the surface of the material studied, the release phase occurs by steps, whose durations correspond to that for the shock wave to go back and forth in the foil. The velocity during the different steps, connected with the knowledge of the Hugoniot of the foil, allows us to determine a few points on the isentropic unloading curve. However, the method becomes insensitive when the low pressure range of vaporization is reached in the course of the unloading. The isentrope in this region can be measured by recording the smooth acceleration of a thin witness plate foil. With the mass of the foil known, measurements of the foil acceleration will give us the vapor pressure

  16. Experiments on helical modes in magnetized thin foil-plasmas

    Science.gov (United States)

    Yager-Elorriaga, David

    2017-10-01

    This paper gives an in-depth experimental study of helical features on magnetized, ultrathin foil-plasmas driven by the 1-MA linear transformer driver at University of Michigan. Three types of cylindrical liner loads were designed to produce: (a) pure magneto-hydrodynamic (MHD) modes (defined as being void of the acceleration-driven magneto-Rayleigh-Taylor instability, MRT) using a non-imploding geometry, (b) pure kink modes using a non-imploding, kink-seeded geometry, and (c) MRT-MHD coupled modes in an unseeded, imploding geometry. For each configuration, we applied relatively small axial magnetic fields of Bz = 0.2-2.0 T (compared to peak azimuthal fields of 30-40 T). The resulting liner-plasmas and instabilities were imaged using 12-frame laser shadowgraphy and visible self-emission on a fast framing camera. The azimuthal mode number was carefully identified with a tracking algorithm of self-emission minima. Our experiments show that the helical structures are a manifestation of discrete eigenmodes. The pitch angle of the helix is simply m / kR , from implosion to explosion, where m, k, and R are the azimuthal mode number, axial wavenumber, and radius of the helical instability. Thus, the pitch angle increases (decreases) during implosion (explosion) as R becomes smaller (larger). We found that there are one, or at most two, discrete helical modes that arise for magnetized liners, with no apparent threshold on the applied Bz for the appearance of helical modes; increasing the axial magnetic field from zero to 0.5 T changes the relative weight between the m = 0 and m = 1 modes. Further increasing the applied axial magnetic fields yield higher m modes. Finally, the seeded kink instability overwhelms the intrinsic instability modes of the plasma. These results are corroborated with our analytic theory on the effects of radial acceleration on the classical sausage, kink, and higher m modes. Work supported by US DOE award DE-SC0012328, Sandia National Laboratories

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

    Science.gov (United States)

    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).

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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 Au 24+ (11 MeV/u) on a thin carbon foil (28 μg/cm 2 )

  19. Comparison between bulk and thin foil ion irradiation of ultra high purity Fe

    Energy Technology Data Exchange (ETDEWEB)

    Prokhodtseva, A., E-mail: anna.prokhodtseva@psi.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland); Décamps, B. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS-IN2P3-Univ. Paris-Sud 11, UMR 8609, Bât. 108, 91405 Orsay (France); Schäublin, R. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland)

    2013-11-15

    Accumulation of radiation damage in ultra high purity iron under self ion irradiation without and with simultaneous He implantation was investigated in bulk and thin foil form to assess, on the one hand, the effect of free surfaces and, on the other hand, the influence of He. Specimens were irradiated at room temperature to a dose of 0.8 dpa and ∼900 appm He content. We found in thin foils after irradiation with single beam a majority of a{sub 0} 〈1 0 0〉 type loops, while in the presence of He it is the ½ a{sub 0} 〈1 1 1〉 type loops that prevail. In single beam irradiated bulk samples most of the loops are of ½ a{sub 0} 〈1 1 1〉 type. In both bulk and thin foils density of defects visible in transmission electron microscope is considerably higher when He is implanted with prevailing ½ a{sub 0} 〈1 1 1〉 dislocation loops, indicating that He stabilizes them.

  20. Measurements of Wake-Riding Electrons in Antiproton-Carbon-Foil Collisions

    CERN Multimedia

    2002-01-01

    When a charged particle passes through dielectric media, e.g. a thin carbon foil, a ``wake'' is induced. The characteristic wake-potential shows an oscillatory behaviour, with a wavelength of about $ 2 \\pi v _{p} / \\omega _{p} _{l} $ where $ v _{p} $ is the projectile velocity and $ \\omega _{p} _{l} $ the plasmon energy of the target. This induced wake potential is superimposed on the Coulomb potential of the projectile, the latter leading to a pronounced ``cusp'' of electrons leaving the solid at $ v _{e} app v _{p} $ for positively charged projectiles in the MeV region. Correspondingly, an ``anti-cusp'' is expected for antiprotons. \\\\ \\\\ In the solid, the wake-potential leads to an attractive force on electrons, and a dynamic electronic state is predicted both for proton and antiproton projectiles. In the solid, the wake-riding electrons are travelling with the projectile speed $ v _{p} $ Upon exit of the foil, the electron released from the wake-riding state of an antiproton will suddenly find itself in th...

  1. DYNAMIC PROPERTIES OF SHOCK LOADED THIN URANIUM FOILS

    International Nuclear Information System (INIS)

    Robbins, D.L.; Kelly, A.M.; Alexander, D.J.; Hanrahan, R.J.; Snow, R.C.; Gehr, R.J.; Rupp, Ted Dean; Sheffield, S.A.; Stahl, D.B.

    2001-01-01

    A series of spall experiments has been completed with thin depleted uranium targets, nominally 0.1 mm thick. The first set of uranium spall targets was cut and ground to final thickness from electro-refined, high-purity, cast uranium. The second set was rolled to final thickness from low purity uranium. The impactors for these experiments were laser-launched 0.05-mm thick copper flyers, 3 mm in diameter. Laser energies were varied to yield a range of flyer impact velocities. This resulted in varying degrees of damage to the uranium spall targets, from deformation to complete spall or separation at the higher velocities. Dynamic measurements of the uranium target free surface velocities were obtained with dual velocity interferometers. Uranium targets were recovered and sectioned after testing. Free surface velocity profiles were similar for the two types of uranium, but spall strengths (estimated from the magnitude of the pull-back signal) are higher for the high-purity cast uranium. Velocity profiles and microstructural evidence of spall from the sectioned uranium targets are presented.

  2. Intense heavy ion beam-induced temperature effects in carbon-based stripper foils

    International Nuclear Information System (INIS)

    Kupka, K.; Tomut, M.; Simon, P.; Hubert, C.; Romanenko, A.; Lommel, B.; Trautmann, C.

    2015-01-01

    At the future FAIR facility, reliably working solid carbon stripper foils are desired for providing intermediate charge states to SIS18. With the expected high beam intensities, the foils experience enhanced degradation and limited lifetime due to severe radiation damage, stress waves, and thermal effects. This work presents systematic measurements of the temperature of different carbon-based stripper foils (amorphous, diamond-like, and carbon-nanotube based) exposed to 4.8 MeV/u U, Bi, and Au beams of different pulse intensities. Thermal and spectroscopic analyses were performed by means of infrared thermography and Fourier transform infrared spectroscopy. The resulting temperature depends on the foil thickness and strongly increases with increasing pulse intensity and repetition rate. (author)

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

    Science.gov (United States)

    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.

  4. Mechanical design and vibro-acoustic testing of ultrathin carbon foils for a spacecraft instrument

    Energy Technology Data Exchange (ETDEWEB)

    Bernardin, John D [Los Alamos National Laboratory; Baca, Allen G [SNL

    2009-01-01

    IBEX-Hi is an electrostatic analyzer spacecraft instrument designed to measure the energy and flux distribution of energetic neutral atoms (ENAs) emanating from the interaction zone between the Earth's solar system and the Milky Way galaxy. A key element to this electro-optic instrument is an array of fourteen carbon foils that are used to ionize the ENAs. The foils are comprised of an ultrathin (50-100 {angstrom} thick) layer of carbon suspended across the surface of an electroformed Nickel wire screen, which in turn is held taught by a metal frame holder. The electro formed orthogonal screen has square wire elements, 12.7 {micro}m thick, with a pitch of 131.1 wires/cm. Each foil holder has an open aperture approximately 5 cm by 2.5 cm. Designing and implementing foil holders with such a large surface area has not been attempted for spaceflight in the past and has proven to be extremely challenging. The delicate carbon foils are subject to fatigue failure from the large acoustic and vibration loads that they will be exposed to during launch of the spacecraft. This paper describes the evolution of the foil holder design from previous space instrument applications to a flight-like IBEX-Hi prototype. Vibro-acoustic qualification tests of the IBEX-Hi prototype instrument and the resulting failure of several foils are summarized. This is followed by a discussion of iterative foil holder design modifications and laser vibrometer modal testing to support future fatigue failure analyses, along with additional acoustic testing of the IBEX-Hi prototype instrument. The results of these design and testing activities are merged and the resulting flight-like foil holder assembly is proposed.

  5. Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

    Directory of Open Access Journals (Sweden)

    Jandro L. Abot

    2018-02-01

    Full Text Available Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more.

  6. Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

    Science.gov (United States)

    Góngora-Rubio, Mário R.; Kiyono, César Y.; Mello, Luis A. M.; Cardoso, Valtemar F.; Rosa, Reinaldo L. S.; Kuebler, Derek A.; Brodeur, Grace E.; Alotaibi, Amani H.; Coene, Marisa P.; Coene, Lauren M.; Jean, Elizabeth; Santiago, Rafael C.; Oliveira, Francisco H. A.; Rangel, Ricardo; Thomas, Gilles P.; Belay, Kalayu; da Silva, Luciana W.; Moura, Rafael T.; Seabra, Antonio C.; Silva, Emílio C. N.

    2018-01-01

    Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more. PMID:29401745

  7. Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

    International Nuclear Information System (INIS)

    Liu, Chuan S.; Shao Xi; Liu, T. C.; Dudnikova, Galina; Sagdeev, Roald Z.; Eliasson, Bengt

    2011-01-01

    We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

  8. Use of Monocrystalline Silicon as Tool Material for Highly Accurate Blanking of Thin Metal Foils

    International Nuclear Information System (INIS)

    Hildering, Sven; Engel, Ulf; Merklein, Marion

    2011-01-01

    The trend towards miniaturisation of metallic mass production components combined with increased component functionality is still unbroken. Manufacturing these components by forming and blanking offers economical and ecological advantages combined with the needed accuracy. The complexity of producing tools with geometries below 50 μm by conventional manufacturing methods becomes disproportional higher. Expensive serial finishing operations are required to achieve an adequate surface roughness combined with accurate geometry details. A novel approach for producing such tools is the use of advanced etching technologies for monocrystalline silicon that are well-established in the microsystems technology. High-precision vertical geometries with a width down to 5 μm are possible. The present study shows a novel concept using this potential for the blanking of thin copper foils with monocrystallline silicon as a tool material. A self-contained machine-tool with compact outer dimensions was designed to avoid tensile stresses in the brittle silicon punch by an accurate, careful alignment of the punch, die and metal foil. A microscopic analysis of the monocrystalline silicon punch shows appropriate properties regarding flank angle, edge geometry and surface quality for the blanking process. Using a monocrystalline silicon punch with a width of 70 μm blanking experiments on as-rolled copper foils with a thickness of 20 μm demonstrate the general applicability of this material for micro production processes.

  9. The production of a homogeneous and well-attached layer of carbon nanofibers on metal foils

    NARCIS (Netherlands)

    Pacheco Benito, Sergio; Lefferts, Leonardus

    2010-01-01

    Carbon nanofibers (CNFs) were deposited on metal foils including nickel (Ni), iron (Fe), cobalt (Co), stainless steel (Fe:Ni; 70:11 wt.%) and mumetal (Ni:Fe; 77:14 wt.%) by the decomposition of C2H4 at 600 °C. The effect of pretreatment and the addition of H2 on the rate of carbon formation, as well

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  12. Flexible supercapacitor electrodes with vertically aligned carbon nanotubes grown on aluminum foils

    Directory of Open Access Journals (Sweden)

    Itir Bakis Dogru

    2016-06-01

    Full Text Available In this work, vertically aligned carbon nanotubes (VACNTs grown on aluminum foils were used as flexible supercapacitor electrodes. Aluminum foils were used as readily available, cheap and conductive substrates, and VACNTs were grown directly on these foils through chemical vapor deposition (CVD method. Solution based ultrasonic spray pyrolysis (USP method was used for the deposition of the CNT catalyst. Direct growth of VACNTs on aluminum foils ruled out both the internal resistance of the supercapacitor electrodes and the charge transfer resistance between the electrode and electrolyte. A specific capacitance of 2.61 mF/cm2 at a scan rate of 800 mV/s was obtained from the fabricated electrodes, which is further improved through the bending cycles.

  13. Gas Gain Measurement Of GEM-Foil In Argon-Carbon Dioxide Mixture

    International Nuclear Information System (INIS)

    Nguyen Ngoc Duy; Vuong Huu Tan; Le Hong Khiem

    2011-01-01

    Nuclear reaction measurement with radioactive beam at low energy plays an important role in nuclear astrophysics and nuclear structure. The trajectory of particle beams can be obtained by using an active gas target, multiple-sampling and tracking proportional chamber (MSTPC), as a proportional counter. Because of intensity of low energy radioactive beam, in the stellar reaction such as (α, p), (p, α), it is necessary to increase the gain for the counter. In this case, a gas electrons multiplier (GEM) foil will be used, so the proportional counter is called GEM-MSTPC. The efficient gas gain of GEM foils which relates to foil thickness and operating pressure was investigated with two type of the foils, 400 μm and 200 μm, in Argon (70%) + Carbon dioxide (30%) mixture. (author)

  14. Vertically aligned carbon nanotube emitter on metal foil for medical X-ray imaging.

    Science.gov (United States)

    Ryu, Je Hwang; Kim, Wan Sun; Lee, Seung Ho; Eom, Young Ju; Park, Hun Kuk; Park, Kyu Chang

    2013-10-01

    A simple method is proposed for growing vertically aligned carbon nanotubes on metal foil using the triode direct current plasma-enhanced chemical vapor deposition (PECVD). The carbon nanotube (CNT) electron emitter was fabricated using fewer process steps with an acid treated metal substrate. The CNT emitter was used for X-ray generation, and the X-ray image of mouse's joint was obtained with an anode current of 0.5 mA at an anode bias of 60 kV. The simple fabrication of a well-aligned CNT with a protection layer on metal foil, and its X-ray application, were studied.

  15. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.; Couty, P.

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano...... calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils...

  16. Dual-chamber/dual-anode proportional counter incorporating an intervening thin-foil solid neutron converter

    International Nuclear Information System (INIS)

    Boatner, Lynn A.; Neal, John S.; Blackston, Matthew A.; Kolopus, James A.; Ramey, Joanne O.

    2012-01-01

    A dual-chamber/dual-anode gas proportional counter utilizing thin solid 6 LiF or 10 B 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 optimum 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 6 LiF-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 6 LiF and 10 B. 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.

  17. Characterizing convective heat transfer using infrared thermography and the heated-thin-foil technique

    International Nuclear Information System (INIS)

    Stafford, Jason; Walsh, Ed; Egan, Vanessa

    2009-01-01

    Convective heat transfer, due to axial flow fans impinging air onto a heated flat plate, is investigated with infrared thermography to assess the heated-thin-foil technique commonly used to quantify two-dimensional heat transfer performance. Flow conditions generating complex thermal profiles have been considered in the analysis to account for dominant sources of error in the technique. Uncertainties were obtained in the measured variables and the influences on the resultant heat transfer data are outlined. Correction methods to accurately account for secondary heat transfer mechanisms were developed and results show that as convective heat transfer coefficients and length scales decrease, the importance of accounting for errors increases. Combined with flow patterns that produce large temperature gradients, the influence of heat flow within the foil on the resultant heat transfer becomes significant. Substantial errors in the heat transfer coefficient are apparent by neglecting corrections to the measured data for the cases examined. Methods to account for these errors are presented here, and demonstrated to result in an accurate measurement of the local heat transfer map on the surface

  18. Polymer-ZnO nanocomposites foils and thin films for UV protection

    International Nuclear Information System (INIS)

    Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya; Yunus, Wan Mahmood Mat

    2014-01-01

    The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images

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

    Energy Technology Data Exchange (ETDEWEB)

    Egoriti, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Politecnico di Milano, Department of Energy, CeSNEF-Nuclear Engineering Division, Via Ponzio, 34/3, 20133 Milano (Italy); Boeckx, S. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); ICTEAM Inst., Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium); Ghys, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Houngbo, D., E-mail: donald.houngbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Gent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Popescu, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)

    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.

  20. Polymer-ZnO nanocomposites foils and thin films for UV protection

    Energy Technology Data Exchange (ETDEWEB)

    Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, University Putra Malaysia, 43400 UPM, Serdang (Malaysia)

    2014-09-03

    The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images.

  1. Charged-particle acceleration through laser irradiation of thin foils at Prague Asterix Laser System

    International Nuclear Information System (INIS)

    Torrisi, Lorenzo; Cutroneo, Maria; Cavallaro, Salvatore; Musumeci, Paolo; Calcagno, Lucia; Wolowski, Jerzy; Rosinski, Marcin; Zaras-Szydlowska, Agnieszka; Ullschmied, Jiri; Krousky, Eduard; Pfeifer, Miroslav; Skala, Jiri; Velyhan, Andreiy

    2014-01-01

    Thin foils, 0.5–50 μm in thickness, have been irradiated in vacuum at Prague Asterix Laser System in Prague using 10 15–16  W cm −2 laser intensity, 1315 nm wavelength, 300 ps pulse duration and different focal positions. Produced plasmas from metals and polymers films have been monitored in the forward and backward directions. Ion and electron accelerations have been investigated by using Thomson parabola spectrometer, x-ray streak camera, ion collectors and SiC semiconductor detectors, the latter employed in time-of-flight configuration. Ion acceleration up to about 3 MeV per charge state was measured in the forward direction. Ion and electron emissions were detected at different angles as a function of the irradiation conditions. (paper)

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

    Science.gov (United States)

    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.

  3. Proton probing of ultra-thin foil dynamics in high intensity regime

    Science.gov (United States)

    Prasad, Rajendra; Aktan, Esin; Aurand, Bastian; Cerchez, Mirela; Willi, Oswald

    2017-10-01

    The field of laser driven ion acceleration has been enriched significantly over the past decade, thanks to the advanced laser technologies. Already, from 100s TW class systems, laser driven sources of particles and radiations are being considered in number of potential applications in science and medicine due to their unique properties. New physical effects unearthed at these systems may help understand and conduct successful experiments at several PW class multi-beam facilities with high rep rate systems, e.g. ELI. Here we present the first experimental results on ultra-thin foil dynamics irradiated by an ultra-high intensity (1020 W/cm2) , ultra-high contrast (10-12) laser pulse at ARCTURUS laser facility at HHU Duesseldorf. By employing the elegant proton probing technique it is observed that for the circular polarization of laser light, a 100nm thin target is pushed forward as a compressed layer due to the radiation pressure of light. Whereas, the linear polarization seems to decompress the target drastically. 2D particle-in-cell simulations corroborate the experimental findings. Our results confirm the previous simulation studies investigating the fundamental role played by light polarization, finite focus spot size effect and eventually electron heating including the oblique incidence at the target edges.

  4. Effects of crystalline structure in the transmission of ions through thin foils

    International Nuclear Information System (INIS)

    Archubi, Claudio

    2005-01-01

    Two fundamental aspects of ion transmission through thin foils are analyzed in this thesis.1) Energy loss.2) Angular distribution.The subject is studied in three different approaches: Theoretically, experimentally and by numerical simulations.In the theoretical approach, the models for the calculation of the energy loss and angular distribution are discussed.They are showed to be unsatisfactory to explain the effects of crystalline structure at low energies.A model is developed to estimate the angular dispersion due to the elastic scattering between the projectile and the target electrons. Simultaneously, angular distribution and energy loss measurements have been performed bombarding polycrystalline and monocrystalline gold and polycrystalline aluminum targets with protons and helium ions with energies in the range of 4-10 keV, together with a detailed study of the foils by electron transmission microscopy techniques.The experimental results are compared with the results of a numerical simulation code, modified and extended in the scope of this thesis.The results show an important influence of crystalline structure and the different targets defects in the angular distribution.This influence is much lower in the case of the angular behaviour of the energy loss (being almost negligible in the case of protons).The most relevant characteristic of the angular behaviour of the energy loss in the case of helium ions is that it is necessary to assume in the simulation method an impact parameter dependence of the stopping coefficient to obtain an agreement between simulation and experimental results [es

  5. Envelope model for passive magnetic focusing of an intense proton or ion beam propagating through thin foils

    Directory of Open Access Journals (Sweden)

    Steven M. Lund

    2013-04-01

    Full Text Available Ion beams (including protons with low emittance and high space-charge intensity can be propagated with normal incidence through a sequence of thin metallic foils separated by vacuum gaps of order the characteristic transverse beam extent to transport/collimate the beam or to focus it to a small transverse spot. Energetic ions have sufficient range to pass through a significant number of thin foils with little energy loss or scattering. The foils reduce the (defocusing radial electric self-field of the beam while not altering the (focusing azimuthal magnetic self-field of the beam, thereby allowing passive self-beam focusing if the magnetic field is sufficiently strong relative to the residual electric field. Here we present an envelope model developed to predict the strength of this passive (beam generated focusing effect under a number of simplifying assumptions including relatively long pulse duration. The envelope model provides a simple criterion for the necessary foil spacing for net focusing and clearly illustrates system focusing properties for either beam collimation (such as injecting a laser-produced proton beam into an accelerator or for magnetic pinch focusing to a small transverse spot (for beam driven heating of materials. An illustrative example is worked for an idealization of a recently performed laser-produced proton-beam experiment to provide guidance on possible beam focusing and collimation systems. It is found that foils spaced on the order of the characteristic transverse beam size desired can be employed and that envelope divergence of the initial beam entering the foil lens must be suppressed to limit the total number of foils required to practical values for pinch focusing. Relatively modest proton-beam current at 10 MeV kinetic energy can clearly demonstrate strong magnetic pinch focusing achieving a transverse rms extent similar to the foil spacing (20–50  μm gaps in beam propagation distances of tens of mm

  6. Surface treatment of glass substrates for the preparation of long-lived carbon stripper foils

    International Nuclear Information System (INIS)

    Takeuchi, Suehiro; Takekoshi, Eiko

    1981-02-01

    Glass substrates having uniformly distributed microscopic grains on the surfaces are useful to make long-lived carbon stripper foils for heavy ions. A method of surface treatment of glass substrates to form the surface structure is described. This method consists of precipitation of glass components, such as soda, onto the surfaces in a hot and humid atmosphere and a fogging treatment of forming microscopic grains of the precipitated substances. Some results of studies on the treatment conditions are also presented. (author)

  7. A thin foil Faraday collector as a lost alpha detector for high yield d-t tokamak fusion plasmas

    International Nuclear Information System (INIS)

    Cecil, F. Ed

    2011-01-01

    This report summarizes the accomplishment of sixteen years of work toward the development of thin foil Faraday collectors as a lost energetic ion diagnostic for high temperature magnetic confinement fusion plasmas. Following initial, proof of principle accelerator based studies, devices have been tested on TFTR, NSTX, ALCATOR, DIII-D, and JET (KA-1 and KA-2). The reference numbers refer to the attached list of publications. The JET diagnostic KA-2 continues in operation and hopefully will provide valuable diagnostic information during a possible d-t campaign on JET in the coming years. A thin Faraday foil spectrometer, by virtue of its radiation hardness, may likewise provide a solution to the very challenging problem of lost alpha particle measurements on ITER and other future burning plasma machines.

  8. Structural and magnetic characterization of martensitic Ni-Mn-Ga thin films deposited on Mo foil

    International Nuclear Information System (INIS)

    Chernenko, V.A.; Anton, R. Lopez; Kohl, M.; Barandiaran, J.M.; Ohtsuka, M.; Orue, I.; Besseghini, S.

    2006-01-01

    Three martensitic Ni 51.4 Mn 28.3 Ga 20.3 thin films sputter-deposited on a Mo foil were investigated with regard to their crystal and magnetic domain structures, as well as their magnetic and magnetostrain properties. The film thicknesses, d, were 0.1, 0.4 and 1.0μm. X-ray and electron diffraction patterns revealed a tetragonal modulated martensitic phase (10M) in the films. The surface topography and micromagnetic structure were studied by scanning probe microscopy. A maze magnetic domain structure featuring a large out-of-plane magnetization component was found in all films. The domain width, δ, depends on the film thickness as δ∼d. The thickness dependencies of the saturation magnetization, saturation magnetic field and magnetic anisotropy were clarified. Beam cantilever tests on the Ni-Mn-Ga/Mo composite as a function of magnetic field showed reversible strains, which are larger than ordinary magnetostriction

  9. Charge fraction of 6.0 MeV/n heavy ions with a carbon foil: Dependence on the foil thickness and projectile atomic number

    CERN Document Server

    Sato, Y; Muramatsu, M; Murakami, T; Yamada, S; Kobayashi, C; Kageyama, Y; Miyoshi, T; Ogawa, H; Nakabushi, H; Fujimoto, T; Miyata, T; Sano, Y

    2003-01-01

    We measured the charge fraction of 6.0 MeV/n heavy ions (C, Ne, Si, Ar, Fe and Cu) with a carbon foil at the NIRS-HIMAC injector. At this energy they are stripped with a carbon foil before being injected into two synchrotron rings with a maximum energy of 800 MeV/n. In order to find the foil thickness (D sub E) at which an equilibrium charge state distribution occurs, and to study the dependence of the D sub E -values on the projectile atomic number, we measured the exit charge fractions for foil thicknesses of between 10 and 350 mu g/cm sup 2. The results showed that the D sub E -values are 21.5, 62.0, 162, 346, 121, 143 mu g/cm sup 2 for C, Ne, Si, Ar, Fe, Cu, respectively. The fraction of Ar sup 1 sup 8 sup + ions was actually improved to 33% at 320 mu g/cm sup 2 from approx 15% at 100 mu g/cm sup 2. For Fe and Cu ions, the D sub E -values were found to be only 121 and 143 mu g/cm sup 2; there is a large gap between Ar and Fe, which is related to the differences in the ratio of the binding energy of the K-...

  10. Interaction of fast Hn+ with the last layers of carbon foils

    International Nuclear Information System (INIS)

    Farizon, M.; Faria, N.V.C. de; Mazuy-Farizon, B.; Gaillard, M.J.

    1993-03-01

    A Monte Carlo program describing the penetration of H n + hydrogen clusters in thin foils has been used to build a model of charge exchange for protons resulting from the breakup of these clusters. The total neutral fractions observed at emergence with cluster projectiles H n + , n < 23 in the energy range 40-120 keV/u, as well as the number of 2p excited states are well reproduced by these calculations taking into account geometrical structures of the projectiles and vicinity effects. (author) 8 refs.; 2 figs

  11. Research of plating aluminum and aluminum foil on internal surface of carbon fiber composite material centrifuge rotor drum

    International Nuclear Information System (INIS)

    Lu Xiuqi; Dong Jinping; Dai Xingjian

    2014-01-01

    In order to improve the corrosion resistance, thermal conductivity and sealability of the internal surface of carbon fiber/epoxy composite material centrifuge rotor drum, magnetron sputtering aluminum and pasting an aluminum foil on the inner wall of the drum are adopted to realize the aim. By means of XRD, SEM/EDS and OM, the surface topography of aluminum coated (thickness of 5 μm and 12 μm) and aluminum foil (12 μm) are observed and analyzed; the cohesion of between aluminum coated (or aluminum foil) and substrate material (CFRP) is measured by scratching experiment, direct drawing experiment, and shear test. Besides, the ultra-high-speed rotation experiment of CFRP ring is carried out to analyze stress and strain of coated aluminum (or aluminum foil) which is adhered on the ring. The results showed aluminum foil pasted on inner surface do better performance than magnetron sputtering aluminum on CFRP centrifuge rotor drum. (authors)

  12. A comparison of EDS microanalysis in FIB-prepared and electropolished TEM thin foils

    International Nuclear Information System (INIS)

    Hutchinson, C.R.; Hackenberg, R.E.; Shiflet, G.J.

    2003-01-01

    This paper reports the results of a fine-probe EDS microanalytical study of cellular precipitation in a Cu-Ti binary alloy. Compositional profiles across the solute depleted Cu-rich FCC lamellae and the Cu 4 Ti lamellae within isothermally formed cellular colonies were measured in a FEG-TEM from thin-foil specimens prepared by conventional electropolishing and by a technique using a Ga + focused ion-beam (FIB). The Cliff-Lorimer ratio method, with an absorption correction, was employed to quantify the compositions. Two FIB samples were prepared with different orientations of the lamellae with respect to the ion-milling direction. The compositional profiles across the Cu-rich FCC lamellae and the Cu 4 Ti compound lamellae in both the FIB-prepared samples and the electropolished sample were, within experimental error, numerically equivalent. The composition of the Cu 4 Ti compound phase lamellae was very close to the ideal stoichiometric composition of 20 at% Ti. It is concluded that for this system, and for the specimen preparation procedures used in this study, the Ga + ion-milling process has had no detectable effect on the chemistry changes across the interlamellar interface at the scale studied. These results indicate that the possible sources of chemical artifacts which include redeposition, preferential sputtering and ion-induced atomic migration can be minimized if several precautions are taken during milling in the FIB. Consistent with previous investigators, it was also found that the ion-milling process does introduce significant structural artifacts (e.g., dislocations) into the softer FCC Cu-rich phase compared with a specimen produced by conventional electropolishing

  13. Development of super thin foil metal supported catalyst; Chousuhaku metal tantai shokubai no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sanji, F; Takada, T [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    In order to improve warm-up performance, high heat resistance and long life durability of catalysts, the reduction of the metal support heat capacity has been focused. The effects of both reducing foil thickness and lowering cell density on low heat capacity have been investigated. As a result of engine bench and vehicle test, it was apparent that the reduction of foil thickness has greater effects. Newly developed 30 {mu} m foil thickness metal supported catalyst has quicker warm-up performance, and its structural durability up to 950degC is confirmed. 3 refs., 11 figs., 1 tab.

  14. X-ray spectroscopy of a thin foil plasma produced by a short-pulse high-intensity laser

    International Nuclear Information System (INIS)

    Audebert, P.; Nagels, V.; Geindre, J.P.; Dorchies, F.; Peyrusse, O.; Gary, S.; Girard, F.; Shepherd, R.; Gauthier, J.C.; Chenais-Popovics, C.

    2003-01-01

    High density and temperature plasmas have been generated by irradiating thin foils of various elements with a high-energy subpicosecond laser pulse. The X-ray emission duration was studied by time-resolved X-ray spectroscopy. Frequency domain interferometry provided a measurement of the hydrodynamic expansion of the back of the foil as a function of time. The effect of longitudinal temperature gradients, i.e., gradients perpendicular to the surface, were decreased using very thin foil targets. Additionally, radial gradients effects, i.e., gradients parallel to the surface, were limited by using a 50 μm pinhole on target. The Al, Se and Sm spectra, recorded in the range 7.7-8 Angst. using a conical crystal spectrometer coupled to an 800 fs resolution streak camera, lasted a few picoseconds. Sm spectra showed no spectral features in this wavelength range, providing a spectrally homogeneous backlighter for future experiments. The main features of the experimental time-resolved spectra have been well reproduced with one-dimensional hydrodynamic simulations of the free expansion of a plasma heated at a given initial temperature obtained from the expansion velocity of the rear critical surface of the plasma

  15. Excimer laser assisted re-oxidation of BaTiO3 thin films on Ni metal foils

    International Nuclear Information System (INIS)

    Bharadwaja, S. S. N.; Ko, S. W.; Qu, W.; Clark, T.; Rajashekhar, A.; Motyka, M.; Podraza, N.; Randall, C. A.; Trolier-McKinstry, S.

    2016-01-01

    Excimer laser assisted re-oxidation for reduced, crystallized BaTiO 3 thin films on Ni-foils was investigated. It was found that the BaTiO 3 can be re-oxidized at an oxygen partial pressure of ∼50 mTorr and substrate temperature of 350 °C without forming a NiO 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 rms excitation signal. Electron Energy Loss Spectroscopy indicated that BaTiO 3 thin films can be re-oxidized to an oxygen stoichiometry close to ∼3 (e.g., stoichiometric). High resolution cross sectional transmission electron microscopy showed no evidence of NiO x formation between the BaTiO 3 and the Ni foil upon excimer laser re-oxidation. Spectroscopic ellipsometry studies on laser re-oxidized [001] C and [111] C BaTiO 3 single crystals indicate that the re-oxidation of BaTiO 3 single crystals is augmented by photo-excitation of the ozone, as well as laser pulse induced temperature and local stress gradients

  16. Development of surface perturbation target and thin silicon foil target used to research Rayleigh-Taylor instability in inertial confinement fusion experiment

    International Nuclear Information System (INIS)

    Zhou Bin; Sun Qi; Huang Yaodong; Shen Jun; Wu Guangming; Wang Jue

    2004-01-01

    The developments of the surface perturbation target and the thin silicon foil target used to research Rayleigh-Taylor instability in the resolved experiments of Inertial Confinement Fusion (ICF) are carried out. Based on the laser interference process combined with the figure-transfer process, the surface perturbation target with sine modulated perturbation is gotten, the wavelength is in the range of 20-100 μm and the amplitude is several micrometers. The thin silicon foil within the thickness about 3-4 μm is prepared by semiconductor process together with heavy-doped self-stop etching. Combined with ion beam etching, the check or the stripe patterns are transferred to the surface of thin silicon foils, and then the silicon grating foil is obtained

  17. A thin two-phase foils deformed by an interfacial dislocation in anisotropic elasticity

    Directory of Open Access Journals (Sweden)

    Madani, Salah

    2005-04-01

    Full Text Available The purpose of this work is the numerical resolution, in the case of anisotropic elasticity, of the problem of a dislocation parallel and near to the two free surfaces of a thin bicrystal. This case is obtained while making the period of a network of misfit dislocations much greater than the thickness of the two foils. As a result, in the vicinity of the dislocation, the limiting bondary conditions will be close to that of Volterra translation dislocation. The elastic fields of displacement and stress are calculated for various orientations of the burgers vector. Before this calculation, we tested the precision of the results of the program by comparing the interfacial relative displacement obtained from this one to the results of the analytical expression describing this same displacement. The thin bicristal Al/Al2Cu, that made the object of several investigations, is treated like example. The results obtained are compared to those obtained in isotropic elasticity.

    Este trabajo aborda la resolución numérica en anisotropía elástica, del problema de una dislocación paralela cercana a las superficies libres de un bi-cristal delgado. Este problema se genera cuando el periodo de la red de dislocaciones desplazadas es mucho mayor que el espesor de la bi-lámina. Como resultados, en la vecindad de la dislocación, las condiciones de contorno estarán cercanas a la dislocación de traslación de Volterra. Los campos elásticos de desplazamiento y las tensiones se calcularon para distintas orientaciones del vector de burgers. Como paso previo a los cálculos, se comprobó la precisión de los resultados del programa comparando le desplazamiento relativo interracial obtenido con los resultados de la expresión analítica que describen dicho desplazamiento. Se emplearon como ejemplo bi-cristales de Al/Al2Cu, debido a su empleo en varias investigaciones. Los resultados fueron comparados con los obtenidos en elasticidad isótropa.

  18. Acceleration{endash}deceleration process of thin foils confined in water and submitted to laser driven shocks

    Energy Technology Data Exchange (ETDEWEB)

    Romain, J.P.; Auroux, E. [Laboratoire de Combustion et de Detonique (UPR 9028 CNRS), ENSMA, BP 109, Teleport 2, Chasseneuil du Poitou, 86960 Futuroscope Cedex (France)

    1997-08-01

    An experimental, numerical, and analytical study of the acceleration and deceleration process of thin metallic foils immersed in water and submitted to laser driven shocks is presented. Aluminum and copper foils of 20 to 120 {mu}m thickness, confined on both sides by water, have been irradiated at 1.06 {mu}m wavelength by laser pulses of {approximately}20ns duration, {approximately}17J energy, and {approximately}4GW/cm{sup 2} incident intensity. Time resolved velocity measurements have been made, using an electromagnetic velocity gauge. The recorded velocity profiles reveal an acceleration{endash}deceleration process, with a peak velocity up to 650 m/s. Predicted profiles from numerical simulations reproduce all experimental features, such as wave reverberations, rate of increase and decrease of velocity, peak velocity, effects of nature, and thickness of the foils. A shock pressure of about 2.5 GPa is inferred from the velocity measurements. Experimental points on the evolution of plasma pressure are derived from the measurements of peak velocities. An analytical description of the acceleration{endash}deceleration process, involving multiple shock and release waves reflecting on both sides of the foils, is presented. The space{endash}time diagrams of waves propagation and the successive pressure{endash}particle velocity states are determined, from which theoretical velocity profiles are constructed. All characteristics of experimental records and numerical simulations are well reproduced. The role of foil nature and thickness, in relation with the shock impedance of the materials, appears explicitly. {copyright} {ital 1997 American Institute of Physics.}

  19. Time-resolved plasma spectroscopy of thin foils heated by a relativistic-intensity short-pulse laser

    International Nuclear Information System (INIS)

    Audebert, P.; Gauthier, J.-C.; Shepherd, R.; Fournier, K.B.; Price, D.; Lee, R.W.; Springer, P.; Peyrusse, O.; Klein, L.

    2002-01-01

    Time-resolved K-shell x-ray spectra are recorded from sub-100 nm aluminum foils irradiated by 150-fs laser pulses at relativistic intensities of Iλ 2 =2x10 18 W μm 2 /cm 2 . The thermal penetration depth is greater than the foil thickness in these targets so that uniform heating takes place at constant density before hydrodynamic motion occurs. The high-contrast, high-intensity laser pulse, broad spectral band, and short time resolution utilized in this experiment permit a simplified interpretation of the dynamical evolution of the radiating matter. The observed spectrum displays two distinct phases. At early time, ≤500 fs after detecting target emission, a broad quasicontinuous spectral feature with strong satellite emission from multiply excited levels is seen. At a later time, the He-like resonance line emission is dominant. The time-integrated data is in accord with previous studies with time resolution greater than 1 ps. The early time satellite emission is shown to be a signature of an initial large area, high density, low-temperature plasma created in the foil by fast electrons accelerated by the intense radiation field in the laser spot. We conclude that, because of this early time phenomenon and contrary to previous predictions, a short, high-intensity laser pulse incident on a thin foil does not create a uniform hot and dense plasma. The heating mechanism has been studied as a function of foil thickness, laser pulse length, and intensity. In addition, the spectra are found to be in broad agreement with a hydrodynamic expansion code postprocessed by a collisional-radiative model based on superconfiguration average rates and on the unresolved transition array formalism

  20. Suppressing propylene carbonate decomposition by coating graphite electrode foil with silver

    International Nuclear Information System (INIS)

    Gao, J.; Zhang, H.P.; Fu, L.J.; Zhang, T.; Wu, Y.P.; Takamura, T.; Wu, H.Q.; Holze, R.

    2007-01-01

    A method has been developed to suppress the decomposition of propylene carbonate (PC) by coating graphite electrode foil with a layer of silver. Results from electrochemical impedance measurements show that the Ag-coated graphite electrode presents lower charge transfer resistance and faster diffusion of lithium ions in comparison with the virginal one. Cyclic voltammograms and discharge-charge measurements suggest that the decomposition of propylene carbonate and co-intercalation of solvated lithium ions are prevented, and lithium ions can reversibly intercalate into and deintercalate from the Ag-coated graphite electrode. These results indicate that Ag-coating is a good way to improve the electrochemical performance of graphitic carbon in PC-based electrolyte solutions

  1. Scanning tunneling microscopy studies of thin foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Besenbacher, Flemming; Garnaes, Jorgen

    1990-01-01

    In this paper scanning tunneling microscopy (STM) measurements of x-ray mirrors are presented. The x-ray mirrors are 0.3 mm thick dip-lacquered aluminum foils coated with gold by evaporation, as well as state-of-the-art polished surfaces coated with gold, platinum, or iridium. The measurements...

  2. Method for making thin carbon foam electrodes

    Science.gov (United States)

    Pekala, Richard W.; Mayer, Steven T.; Kaschmitter, James L.; Morrison, Robert L.

    1999-01-01

    A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers/powders, or fabrics with an appropriate carbon foam precursor material. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays flat and flexible during curing and pyrolyzing to form thin sheets. Precursor materials include polyacrylonitrile (PAN), polymethylacrylonitrile (PMAN), resorcinol/formaldehyde, catechol/formaldehyde, phenol/formaldehyde, etc., or mixtures thereof. These thin films are ideal for use as high power and energy electrodes in batteries, capacitors, and fuel cells, and are potentially useful for capacitive deionization, filtration and catalysis.

  3. First experience with carbon stripping foils for the 160 MeV H- injection into the CERN PSB

    Science.gov (United States)

    Weterings, Wim; Bracco, Chiara; Jorat, Louise; Noulibos, Remy; van Trappen, Pieter

    2018-05-01

    160 MeV H- beam will be delivered from the new CERN linear accelerator (Linac4) to the Proton Synchrotron Booster (PSB), using a H- charge-exchange injection system. A 200 µg/cm2 carbon stripping foil will convert H- into protons by stripping off the electrons. The H- charge-exchange injection principle will be used for the first time in the CERN accelerator complex and involves many challenges. In order to gain experience with the foil changing mechanism and the very fragile foils, in 2016, prior to the installation in the PSB, a stripping foil test stand has been installed in the Linac4 transfer line. In addition, parts of the future PSB injection equipment are also temporarily installed in the Linac4 transfer line for tests with a 160 MeV H- commissioning proton beam. This paper describes the foil changing mechanism and control system, summarizes the practical experience of gluing and handling these foils and reports on the first results with beam.

  4. Comparison of carbon stripper foils produced by ARC discharge and laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Ophel, T.R.; Rhode, A.; Lobanov, N.; Weisser, D.C.; Turkentine, R.; Wolf, B.; Wlliman, R.G. [Australian National Univ. Canberra, ACT (Australia). Research School of Physical Sciences and Engineering

    1998-06-01

    The present work describes a series of investigations which compared the arc-deposited foils, prepared at ANU with a batch of foils from Munich, prepared by laser-ablation. The two foil types were bombarded with a beam of 6.8 MeV of {sup 197}Au recording their behaviour and monitoring the total stripped current. Optical and electron spectroscopy was carried out and indicate that the arc-deposited foils were relatively amorphous and smooth, while the laser-ablated foils appears to be much more crystalline. It was found that the average useful lifetimes of the Munich foils were at least ten times longer than arc-deposited foils. Furthermore, they maintained a constant beam output during the time in marked contrast to the arc-deposited foils, for which the output decreased quite rapidly. The longevity, and no less importantly, the constant beam output of the laser-ablated foils have emerged as critical to the continuance of the ERDA program. More significantly though, such qualities have provoked re-examination of likely energies for heavy beams that could be obtained with the Linac booster if foil stripping were used in the 14UD terminal, rather than gas that had previously been considered the only viable option. A program is in progress to explore the means to produce laser-ablated foils, or their equivalent, locally. Extended abstract. 1 ref., 2 figs.

  5. Comparison of carbon stripper foils produced by ARC discharge and laser ablation

    International Nuclear Information System (INIS)

    Ophel, T.R.; Rhode, A.; Lobanov, N.; Weisser, D.C.; Turkentine, R.; Wolf, B.; Wlliman, R.G.

    1998-01-01

    The present work describes a series of investigations which compared the arc-deposited foils, prepared at ANU with a batch of foils from Munich, prepared by laser-ablation. The two foil types were bombarded with a beam of 6.8 MeV of 197 Au recording their behaviour and monitoring the total stripped current. Optical and electron spectroscopy was carried out and indicate that the arc-deposited foils were relatively amorphous and smooth, while the laser-ablated foils appears to be much more crystalline. It was found that the average useful lifetimes of the Munich foils were at least ten times longer than arc-deposited foils. Furthermore, they maintained a constant beam output during the time in marked contrast to the arc-deposited foils, for which the output decreased quite rapidly. The longevity, and no less importantly, the constant beam output of the laser-ablated foils have emerged as critical to the continuance of the ERDA program. More significantly though, such qualities have provoked re-examination of likely energies for heavy beams that could be obtained with the Linac booster if foil stripping were used in the 14UD terminal, rather than gas that had previously been considered the only viable option. A program is in progress to explore the means to produce laser-ablated foils, or their equivalent, locally

  6. Measurements of direct drive laser imprint in thin foils by XUV radiography using an X-ray laser backlighter

    International Nuclear Information System (INIS)

    Kalantar, D.H.; Key, M.H.; DaSilva, L.B.

    1996-11-01

    In direct drive inertial confinement fusion, the residual speckle pattern remaining after beam smoothing plays an important role in the seeding of instabilities at the ablation front. We have used an x-ray laser as an XUV backlighter to characterize the imprinted modulation in thin foils for smoothing by random phase plate and spectral dispersion at both 0.35 pm and 0.53 pm irradiation, and induced spatial incoherence at 0.53 pm irradiation. We also demonstrate measurements of the modulation due to a single mode optical imprint generated by a narrow slit interference pattern, and modification of the imprint with a superposed smooth irradiation to study time dependence of the imprinting process. 8 refs., 10 figs

  7. Measurements of direct drive laser imprint in thin foils by radiography using an x-ray laser backlighter

    International Nuclear Information System (INIS)

    Kalantar, D.H.; Key, M.H.; Da Silva, L.B.; Glendinning, S.G.; Remington, B.A.; Rothenberg, J.E.; Weber, F.; Weber, S.V.; Wolfrum, E.; Kim, N.S.; Neely, D.; Zhang, J.; Wark, J.S.; Demir, A.; Lin, J.; Smith, R.; Tallents, G.J.; Lewis, C.L.; MacPhee, A.; Warwick, J.; Knauer, J.P.

    1997-01-01

    In direct drive inertial confinement fusion, the residual speckle pattern remaining after beam smoothing plays an important role in the seeding of instabilities at the ablation front. An x-ray laser is used as an extreme ultraviolet backlighter to characterize the imprinted modulation in thin foils for smoothing by random phase plate and by spectral dispersion for both 0.35 and 0.53 μm irradiation, and by induced spatial incoherence for 0.53 μm irradiation. Measurements of the imprinted modulation due to a single optical mode generated by two beam interference, and modification of the imprint with a superposed smooth irradiation to study time dependence of the imprinting process are demonstrated. copyright 1997 American Institute of Physics

  8. Resonant absorption effects induced by polarized laser ligth irradiating thin foils in the tnsa regime of ion acceleration

    International Nuclear Information System (INIS)

    Torrisi, L.; Badziak, J.; Rosinski, M.; Zaras-Szydlowska, A.; Pfeifer, M.; Torrisi, A.

    2016-01-01

    Thin foils were irradiated by short pulsed lasers at intensities of 10 16−19 W/cm 2 in order to produce non-equilibrium plasmas and ion acceleration from the target-normal-sheath-acceleration (TNSA) regime. Ion acceleration in forward direction was measured by SiC detectors and ion collectors used in the time-of-flight configuration. Laser irradiations were employed using p-polarized light at different incidence angles with respect to the target surface and at different focal distances from the target surface. Measurements demonstrate that resonant absorption effects, due to the plasma wave excitations, enhance the plasma temperature and the ion acceleration with respect to those performed without to use of p-polarized light. Dependences of the ion flux characteristics on the laser energy, wavelength, focal distance and incidence angle will be reported and discussed

  9. A nanostructured electrode of IrOx foil on the carbon nanotubes for supercapacitors

    Science.gov (United States)

    Chen, Yi-Min; Cai, Jhen-Hong; Huang, Ying-Sheng; Lee, Kuei-Yi; Tsai, Dah-Shyang; Tiong, Kwong-Kau

    2011-09-01

    IrOx nanofoils (IrOxNF) of high surface area are sputtered on multi-wall carbon nanotubes (CNT) in the preparation of a structured electrode on a stainless steel (SUS) substrate for supercapacitor applications. This IrOx/CNT/SUS electrode is featured with intriguing IrOx curved foils of 2-3 nm in thickness and 400-500 nm in height, grown on top of the vertically aligned CNT film with a tube diameter of ~ 40 nm. These nanofoils are moderately oxidized during reactive sputtering and appeared translucent under the electron microscope. Detailed structural analysis shows that they are comprised of contiguous grains of iridium metal, iridium dioxide, and glassy iridium oxide. Considerable Raman line broadening is also evidenced for the attributed nanosized iridium oxides. Two capacitive properties of the electrode are significantly enhanced with addition of the curved IrOx foils. First, IrOxNF reduces the electrode Ohmic resistance, which was measured at 3.5 Ω cm2 for the CNT/SUS and 2.5 Ω cm2 for IrOxNF/CNT/SUS using impedance spectroscopy. Second, IrOxNF raises the electrode capacitance from 17.7 F g - 1 (CNT/SUS) to 317 F g - 1 (IrOx/CNT/SUS), measured with cyclic voltammetry. This notable increase is further confirmed by the galvanostatic charge/discharge experiment, measuring 370 F g - 1 after 2000 uninterrupted cycles between - 1.0 and 0.0 V (versus Ag/AgCl).

  10. A nanostructured electrode of IrO{sub x} foil on the carbon nanotubes for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yi-Min; Cai, Jhen-Hong; Huang, Ying-Sheng; Lee, Kuei-Yi [Department of Electronic Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan (China); Tsai, Dah-Shyang [Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan (China); Tiong, Kwong-Kau, E-mail: ysh@mail.ntust.edu.tw [Department of Electrical Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China)

    2011-09-02

    IrO{sub x} nanofoils (IrO{sub x}NF) of high surface area are sputtered on multi-wall carbon nanotubes (CNT) in the preparation of a structured electrode on a stainless steel (SUS) substrate for supercapacitor applications. This IrO{sub x}/CNT/SUS electrode is featured with intriguing IrO{sub x} curved foils of 2-3 nm in thickness and 400-500 nm in height, grown on top of the vertically aligned CNT film with a tube diameter of {approx} 40 nm. These nanofoils are moderately oxidized during reactive sputtering and appeared translucent under the electron microscope. Detailed structural analysis shows that they are comprised of contiguous grains of iridium metal, iridium dioxide, and glassy iridium oxide. Considerable Raman line broadening is also evidenced for the attributed nanosized iridium oxides. Two capacitive properties of the electrode are significantly enhanced with addition of the curved IrO{sub x} foils. First, IrO{sub x}NF reduces the electrode Ohmic resistance, which was measured at 3.5 {Omega} cm{sup 2} for the CNT/SUS and 2.5 {Omega} cm{sup 2} for IrO{sub x}NF/CNT/SUS using impedance spectroscopy. Second, IrO{sub x}NF raises the electrode capacitance from 17.7 F g{sup -1} (CNT/SUS) to 317 F g{sup -1} (IrO{sub x}/CNT/SUS), measured with cyclic voltammetry. This notable increase is further confirmed by the galvanostatic charge/discharge experiment, measuring 370 F g{sup -1} after 2000 uninterrupted cycles between - 1.0 and 0.0 V (versus Ag/AgCl).

  11. Preparation of location-specific thin foils from Fe-3%Si bi- and tri- crystals for examination in a FEG-STEM

    Czech Academy of Sciences Publication Activity Database

    Sorbello, F.; Hughes, G.M.; Lejček, Pavel; Heard, P.J.; Flewitt, P.E.J.

    2009-01-01

    Roč. 109, č. 2 (2009), 147-153 ISSN 0304-3991 R&D Projects: GA AV ČR IAA1010414 Institutional research plan: CEZ:AV0Z10100520 Keywords : FEG-STEM * Fe-3%Si * Thin foils * focused ion beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.067, year: 2009

  12. Penetration of Hydrogen clusters from 10 to 120 kev/u in carbon foils. Study of their slowing-down and charge distribution of emerging fragments

    International Nuclear Information System (INIS)

    Ray, E.M.

    1991-06-01

    This work is devoted to the experimental study of the interaction between fast (10 to 120 keV/p) hydrogen clusters with thin solid targets. First, we have studied the slowing-down of H n + (2≤n≤21) clusters through carbon foils. Up to date this had been made only with molecular ions. We obtain evidence for vicinage effects on the energy loss of proton-clusters. We show that for projectile energies larger than 50 keV/p, the energy loss of a proton in a cluster is enhanced when compared to that of an isolated proton of the same velocity. At lower incident energies, it is a decrease of the energy loss which is observed. The same effect is also observed in the energy lost in the entrance window of a surface barrier detector bombarded by clusters. This phenomenon is interpreted in terms of interferences between individual polarisation wakes induced by each proton of the cluster. In the second part, we propose an accurate method to study the charge state of the atomic fragments resulting from the dissociation of fast H n + (2≤n≤15) clusters through a carbon foil. This method gives also the distribution of the neutral atoms among the emerging fragments. These distributions are finally compared with binomial laws expected from independent particles

  13. Low-Energy Electrons Emitted in Ion Collisions with Thin Foils

    Science.gov (United States)

    Kraemer, Michael; Kozhuharov, Christophor; Durante, Marco; Hagmann, Siegbert; Kraft, Gerhard; Lineva, Natallia

    this end, electron spectra were measured from collisions of 3.6 and 11.4 MeV/u carbon ions impinging on thin (4 to 40ug/cm**2) C, Ni, Ag, and Au targets. The results were compared with simple conventional theories as well as with dedicated TRAX Monte Carlo simulations taking transport through the material into account. We will discuss the importance of the projectile electrons as well as the instantaneous charge state of the projectile within the target material. These investigations were complemented with protons in comparison with singly charged H3 molecules as projectiles. The fact that the ratio of the cross sections for electron production is not unity and slightly increases with the electron energy supports the emphasis that we put on the importance of the projectile electrons and on the knowledge of the instantaneous charge state. The spectra further exhibit two structures that belong to the KLL-Auger lines of carbon and oxygen. The C-line originates from the target surface and from the adsorbed carbon; the O-line originates entirely from the adsorbed oxygen molecules. It appears that the line structure can be explained by the back-diffusion of the Auger electrons.

  14. Characterisation of electrodeposited polycrystalline uranium dioxide thin films on nickel foil for industrial applications

    International Nuclear Information System (INIS)

    Adamska, A.M.; Bright, E. Lawrence; Sutcliffe, J.; Liu, W.; Payton, O.D.; Picco, L.; Scott, T.B.

    2015-01-01

    Polycrystalline uranium dioxide thin films were grown on nickel substrates via aqueous electrodeposition of a precursor uranyl salt. The arising semiconducting uranium dioxide thin films exhibited a tower-like morphology, which may be suitable for future application in 3D solar cell applications. The thickness of the homogenous, tower-like films reached 350 nm. Longer deposition times led to the formation of thicker (up to 1.5 μm) and highly porous films. - Highlights: • Electrodeposition of polycrystalline UO_2 thin films • Tower-like morphology for 3D solar cell applications • Novel technique for separation of heavy elements from radioactive waste streams

  15. Laser Welding of Silicon Foils for Thin-Film Solar Cell Manufacturing

    OpenAIRE

    Heßmann, Maik

    2014-01-01

    Thin-film solar module manufacturing is one of the most promising recent developments in photovoltaic research and has the potential to reduce production costs. As the necessity for competitive prices on the world market increases and manufacturers endeavor to bring down the cost of solar modules, thin-film technology is becoming more and more attractive. In this work a special technique was investigated which makes solar cell manufacturing more compatible with an industrial roll-to-roll proc...

  16. Development of thin foil Faraday collector as a lost alpha particle diagnostic for high yield D-T tokamak fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Van Belle, P; Jarvis, O N; Sadler, G J [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Cecil, F E [Colorado School of Mines, Golden, CO (United States)

    1994-07-01

    Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.

  17. Some observations on the carburization of type 316 stainless steel foil in a low carbon activity sodium environment

    International Nuclear Information System (INIS)

    Thorley, A.W.; Jeffcoat, P.J.

    1982-01-01

    Work currently being undertaken to establish the equilibrium composition of carbides which form in stainless steel foils during their exposure to low carbon activity sodium environment is described. The time it takes the carbon to reach equilibrium during exposure to sodium of different carbon activity is discussed. The lowest carbon activity measureable in test loops where the sodium is just above carburizing to stainless steel is reported. Analytical techniques are used to determine the composition of the carbide and the austenite matrix and hence estimate the carbon activity of the equilibrium structure. This provides a comparison with carbon activity values determined by alternative methods such as the Harwell Carbon Meter and nickel tab techniques

  18. Experimental Studies of the Electrothermal and Magneto-Rayleigh Taylor Instabilities on Thin Metal Foil Ablations

    Science.gov (United States)

    Steiner, Adam; Yager-Elorriaga, David; Patel, Sonal; Jordan, Nicholas; Gilgenbach, Ronald; Lau, Y. Y.

    2015-11-01

    The electrothermal instability (ETI) and magneto-Rayleigh Taylor instability (MRT) are important in the implosion of metallic liners, such as magnetized liner implosion fusion (MagLIF). The MAIZE linear transformer driver (LTD) at the University of Michigan generates 200 ns risetime-current pulses of 500 to 600 kA into Al foil liners to study plasma instabilities and implosion dynamics, most recently MRT growth on imploding cylindrical liners. A full circuit model of MAIZE, along with I-V measurements, yields time-resolved load inductance. This has enabled measurements of an effective current-carrying radius to determine implosion velocity and plasma-vacuum interface acceleration. Measurements are also compared to implosion data from 4-time-frame laser shadowgraphy. Improved resolution measurements on the laser shadowgraph system have been used to examine the liner interface early in the shot to examine surface perturbations resulting from ETI for various seeding conditions. Fourier analysis examines the growth rates of wavelength bands of these structures to examine the transition from ETI to MRT. This work was supported by the U.S. DoE through award DE-SC0012328. S.G. Patel is supported by Sandia National Labs. D.A. Yager is supported by NSF fellowship grant DGE 1256260.

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

    Science.gov (United States)

    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.

  20. Recent progress in particle acceleration from the interaction between thin-foil targets and J-KAREN laser pulses

    Science.gov (United States)

    Nishiuchi, Mamiko; Pirozhkov, Alexander S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, Timur Zh; Tanimoto, Tsuyoshi; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; Kanasaki, Masato; Kiriyama, Hiromitsu; Shimomura, Takuya; Tanoue, Manabu; Nakai, Yoshiki; Sasao, Hajime; Sasao, Fumitaka; Kanazawa, Shuhei; Kondo, Shuji; Matsumoto, Yoshihiro; Sakai, Seiji; Brenner, Ceri; Neely, David; Bulanov, Sergei V.; Kondo, Kiminori

    2012-07-01

    From the interaction between the high-contrast (˜more than 1010) 130 TW Ti:sapphire laser pulse and Stainless Steel-2.5 um-thick tape target, proton beam with energies up to 23 MeV with the conversion efficiency of ˜1% is obtained. After plasma mirror installation for contrast improvement, from the interaction between the 30 TW laser pulse and thin-foil target installed on the target holder with the hole whose shape is associated with the design of the well-known Wehnelt electrode of electron-gun, a 7 MeV intense proton beam is controlled dynamically and energy selected by the self-induced quasi-static electric field on the target holder. From the highly divergent beam having continuous spectrum, which are the typical features of the laser-driven proton beams from the interactions between the short-pulse laser and solid target, the spatial distribution of 7 MeV proton bunch is well manipulated to be focused to an small spots with an angular distribution of ˜10 mrad. The number of protons included in the bunch is >106.

  1. Evolution of sausage and helical modes in magnetized thin-foil cylindrical liners driven by a Z-pinch

    Science.gov (United States)

    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.

  2. Structural damage in thin SLIM-Cut c-Si foils fabricated for solar cell purposes: atomic assessment by electron spin resonance

    International Nuclear Information System (INIS)

    Kepa, J; Stesmans, A; Martini, R

    2015-01-01

    Within the context of reducing production costs, thin (<90 μm) silicon foils intended for photovoltaic applications have been fabricated from standard (100)Si wafers using a low-temperature (<150 °C) stress-induced lift-off process. A multi-frequency electron spin resonance (ESR) study was performed in order to evaluate, at atomic scale, the quality of the material in terms of defects, including identification and quantification. Generally, a complex ESR spectrum is observed, disentangled as the superposition of three separate signals. This includes, most prominently (∼91% of total density) the D-line (Si 3  ≡ Si· dangling bonds in a disordered Si environment), a set (∼6%) of highly anisotropic signals ascribed to dislocations (K1-like), and a triplet, identified as the Si-SL5 N-donor defect. Defect density depth profiling from the lift-off side shows all signals disappear in tandem after etching off a ∼33 μm thick Si layer, indicating a highly correlated−equal in relative terms−distribution of the three types of defects over the affected top part of the Si foil. The defect density is found to be highly non-uniform laterally, with the density peaking near the crack initiation point, from which defect generation spreads. It is thus found that the SLIM-Cut method for fabrication of thin Si foils results in the introduction of defects that would unacceptably impair the functionality of photovoltaic cells built on these substrates. Fortunately, this may be cured by etching off a thin top Si layer, resulting in a most useful thin Si foil of standard high quality. (paper)

  3. Surface effects in the energy loss of ions passing through a thin foil

    International Nuclear Information System (INIS)

    Osma, J.; Garcia de Abajo, F.J.

    1997-01-01

    The role of surface plasmon excitation in the interaction of ions passing through thin films has been studied in both the Bloch hydrodynamic approximation and the local response approach for projectile velocities above the maximum of the stopping power curve. The effect of the surface is found to be much weaker when the dispersion of the modes is taken into consideration than in the case of nondispersive media, though qualitatively the main features of the hydrodynamic approach resemble those of the local one. A generalization of the Bothe-Landau convolution formula for the loss probability distribution is derived to take into account the scattering due to the surface. The effects of the surface in the energy-loss spectra are discussed. A comparison with experiment is given. copyright 1997 The American Physical Society

  4. Moving foil stripper for a particle accelerator

    International Nuclear Information System (INIS)

    Gorka, A.J. Jr.

    1975-01-01

    Thin foils for stripping a particle beam are stored on the edge of a disk spinning in the accelerator vacuum. Cutting a foil at one edge releases the foil to project beyond the disk for insertion into the beam at a time determined by controlling the phase of the disk. A wiper removes a spent foil from the disk. The foil release and wiper are operable from a remote location. (U.S.)

  5. Study on lifetime of C stripping foils

    International Nuclear Information System (INIS)

    Zhang Hongbin; Lu Ziwei; Zhao Yongtao; Li Zhankui; Xu Hushan; Xiao Guoqing; Wang Yuyu; Zhang Ling; Li Longcai; Fang Yan

    2007-01-01

    The carbon stripping foils can be prepared with the AC and DC arc discharge methods, or even sandwiched with AC-DC alternative layers. The lifetime of the carbon stripping foils of 19 μg/cm 2 prepared with different methods and/or structures was measured. The factors affecting the bombarding lifetime of the carbon stripping foils, especially the method of the foil preparation and the structure of the carbon stripping foils, were discussed. It is observed that the foils prepared with the DC arc discharge method have a longer bombarding lifetime than those prepared with the AC arc discharge method. (authors)

  6. Quantifying clustering in disordered carbon thin films

    International Nuclear Information System (INIS)

    Carey, J.D.

    2006-01-01

    The quantification of disorder and the effects of clustering in the sp 2 phase of amorphous carbon thin films are discussed. The sp 2 phase is described in terms of disordered nanometer-sized conductive sp 2 clusters embedded in a less conductive sp 3 matrix. Quantification of the clustering of the sp 2 phase is estimated from optical as well as from electron and nuclear magnetic resonance methods. Unlike in other disordered group IV thin film semiconductors, we show that care must be exercised in attributing a meaning to the Urbach energy extracted from absorption measurements in the disordered carbon system. The influence of structural disorder, associated with sp 2 clusters of similar size, and topological disorder due to undistorted clusters of different sizes is also discussed. Extensions of this description to other systems are also presented

  7. Carbon footprint of a reflective foil and comparison with other solutions for thermal insulation in building envelope

    International Nuclear Information System (INIS)

    Proietti, Stefania; Desideri, Umberto; Sdringola, Paolo; Zepparelli, Francesco

    2013-01-01

    Highlights: ► Environmental and energy assessment of thermal insulating materials in building envelope. ► Carbon footprint of a reflective foil, conceived and produced by an Italian company. ► Study conducted according to principles of LCA – Life Cycle Assessment. ► Identification of main impacting processes and measures for reducing emissions. ► Comparison with traditional insulating materials (EPS and rockwool). - Abstract: The present study aims at assessing environmental and energy compatibility of different solutions of thermal insulation in building envelope. In fact a good insulation results in a reduction of heating/cooling energy consumptions; on the other hand construction materials undergo production, transformation and transport processes, whose energy and resources consumptions may lead to a significant decrease of the environmental benefits. The paper presents a detailed carbon footprint of a product (CFP, defined as the sum of greenhouse gas emissions and removals of a product system, expressed in CO 2 equivalents), which is a reflective foil conceived and produced by an Italian company. CFP can be seen as a Life Cycle Assessment with climate change as the single impact category; it does not assess other potential social, economic and environmental impacts arising from the provision of products. The analysis considers all stages of the life cycle, from the extraction of raw materials to the product’s disposal, i.e. “from cradle to grave”; it was carried out according to UNI EN ISO 14040 and 14044, and LCA modelling was performed using SimaPro software tool. On the basis of obtained results, different measures have been proposed in order to reduce emissions in the life cycle and neutralize residual carbon footprint. The results allowed to make an important comparison concerning the environmental performance of the reflective foil in comparison with other types of insulating materials

  8. A discrete-time amplifier based on Thin-Film Trans-Capacitors for sensor systems on foil

    OpenAIRE

    Raiteri, D.; Roermund, van, A.H.M.; Cantatore, E.

    2014-01-01

    Organic materials can be used to fabricate sensors for physical and chemical quantities, and also to make electronics. The integration of these two elements holds the promise to enable novel smart-sensors on foil. In this paper, we deal with the design of the first stage of a signal conditioning chain on foil: the amplifier. The poor electrical performance of organic TFTs hampers the design of complex circuits, and negatively affects the characteristics of continuous-time amplifiers. In order...

  9. A study of molecular effects in beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Andresen, B.; Veje, E.

    1979-01-01

    Relative populations of ns + nd levels in hydrogen as functions of the principal quantum number n have been measured with beams of H + , H 2 + , and H 3 + impinging on thin carbon foils at 25 keV/amu and 100 keV/amu. Enhancements of 20% and 45% for dimer and trimer clusters are observed uniformly for all levels. A possible explanation in terms of screening of the Coulomb repulsion between the protons inside the foil, thus reducing the effective thickness of the foil, is given. All relative populations closely follow an nsup(P) power law with p = -4.0 and -3.7 at 25 keV/amu and 100 keV/amu, respectively, in perfect analogy with atomic collision experiments. O + /O 2 + -foil excitations at 100 keV and 155 keV show a simular molecular effect, but in reverse with a larger mean charge produced by the dimer. (Auth.)

  10. The production of carbon nanofibers and thin films on palladium catalysts from ethylene oxygen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Jonathan [Los Alamos National Laboratory; Doorn, Stephen [Los Alamos National Laboratory; Atwater, Mark [UNM MECH.ENG.; Leseman, Zayd [UNM MECH.ENG.; Luhrs, Claudia C [UNM ENG.MECH; Diez, Yolanda F [SPAIN; Diaz, Angel M [SPAIN

    2009-01-01

    The characteristics of carbonaceous materials deposited in fuel rich ethylene-oxygen mixtures on three types of palladium: foil, sputtered film, and nanopowder, are reported. It was found that the form of palladium has a dramatic influence on the morphology of the deposited carbon. In particular, on sputtered film and powder, tight 'weaves' of sub-micron filaments formed quickly. In contrast, on foils under identical conditions, the dominant morphology is carbon thin films with basal planes oriented parallel to the substrate surface. Temperature, gas flow rate, reactant flow ratio (C2H4:02), and residence time (position) were found to influence both growth rate and type for all three forms of Pd. X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed oxidation, and Raman spectroscopy were used to assess the crystallinity of the as-deposited carbon, and it was determined that transmission electron microscopy and x-ray diffraction were the most reliable methods for determining crystallinity. The dependence of growth on reactor position, and the fact that no growth was observed in the absence of oxygen support the postulate that the carbon deposition proceeds by combustion generated radical species.

  11. Electron microscope observation of single - crystalline beryllium thin foils; Observation de lames minces monocristallines de beryllium en microscopie electronique

    Energy Technology Data Exchange (ETDEWEB)

    Antolin, J; Poirier, J P; Dupouy, J M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Thin foils prepared from single crystalline beryllium simples deformed at room temperature, have been observed by transmission electron microscopy. The various deformation modes have been investigated separately, from their early stages and their characteristic dislocation configurations have been observed. Basal slip is characterized at is outset by the presence of numerous dipoles and elongated prismatic loops. More pronounced cold work leads to the formation of dislocation tangles and bundles which eventually give a cellular structure. Prismatic slip begins by the cross-slip of dislocations from the basal plane into the prismatic plane. A cellular structure is equally observed in heavily deformed samples. Sessile dislocations have been observed in twin boundaries; they are produced by reactions between slip dislocations and twin dislocations. Finally, the study of samples quenched from 1100 deg. C and annealed at 200 deg. C has shown that the observed loops lie in prismatic planes and have a Burgers vector b 1/3<1 1 2-bar 0>. (authors) [French] On a observe en microscopie electronique par transmission des lames minces tirees d'eprouvettes monocristallines de beryllium deformees a l'ambiante. On a etudie separement les differents modes de deformation a partir de leur stade elementaire en observant les configurations de dislocations caracteristiques. Le glissement basal est caracterise a son debut par la presence de nombreux dipoles et de boucles prismatiques allongees. Des ecrouissages plus forts conduisent a la formation d'echeveaux et de gerbes qui finissent par donner une structure cellulaire. Le glissement prismatique debute par le glissement des dislocations hors du plan de base dans les plans prismatiques. On trouve egalement une structure cellulaire pour de forts ecrouissages. Dans les joints de macle, on a observe des dislocations sessiles formees par la reaction entre dislocations de macle et dislocations de glissement. Enfin l'etude d

  12. Electron emission resulting from fast ion impact on thin metal foils: Implications of these data for development of track structure models

    Energy Technology Data Exchange (ETDEWEB)

    DuBois, R.D.; Drexler, C.G.

    1993-04-01

    Experimental information useful in improving and testing theoretical models of energy deposition and redistribution in particle-condensed phase media is discussed. An overview of information available from previous, and ongoing, studies of the electron emission from thin foils is presented and the need for doubly differential electron energy and angular distribution data stressed. Existing data are used to demonstrate that precisely known, and controllable, surface and bulk conditions of the condensed-phase media are required for experimental studies of this type. Work in progress and improvements planned for future studies at the Pacific Northwest Laboratory are outlined.

  13. A discrete-time amplifier based on Thin-Film Trans-Capacitors for sensor systems on foil

    NARCIS (Netherlands)

    Raiteri, D.; Roermund, van A.H.M.; Cantatore, E.

    2014-01-01

    Organic materials can be used to fabricate sensors for physical and chemical quantities, and also to make electronics. The integration of these two elements holds the promise to enable novel smart-sensors on foil. In this paper, we deal with the design of the first stage of a signal conditioning

  14. Dissociation of fast HeH+ ions in foils and gases

    International Nuclear Information System (INIS)

    Gemmell, D.S.; Cooney, P.J.; Pietsch, W.J.; Ratkowski, A.J.; Vager, Z.

    1978-01-01

    To gain understanding of phenomena observed when very simple light diatomic ions are incident at high velocities upon thin foils and gaseous targets, an extensive set of measurements on the dissociation products arising from beams of HeH + was made. Experimental and calculated joint distributions in energy and angle for protons emerging (near the beam direction) from an 85-A carbon foil bombarded by 2.0-MeV HeH + ions are presented

  15. Thin-foil phase transformations of tetragonal ZrO/sub 2/ in a ZrO/sub 2/-8 wt% Y/sub 2/O/sub 3/ alloy

    International Nuclear Information System (INIS)

    Bestgen, H.; Chaim, R.; Heuer, A.H.

    1988-01-01

    Tetragonal zirconia (t-ZrO/sub 2/) grains in an annealed ZrO/sub 2/-8 wt% Y/sub 2/O/sub 3/ alloy transformed to orthorhombic (o) or mono-clinic (m) symmetry by stresses induced by localized electron beam heating in the transmission electron microscope. Different transformation mechanisms were observed, depending on foil thickness and orientation of individual grains. In thicker grains (≥150 nm), the transformation proceeded by a burst-like growth of m laths, and this is believed to approximate bulk behavior. In thinner grains near the edge of the foil, usually those with a [100]/sub t/ orientation perpendicular to the thin-foil surface, continuous growth of an o or m phase with an antiphase-boundary-containing microstructure was observed. The o phase is believed to be a high-pressure polymorph of ZrO/sub 2/, which forms (paradoxically) as a thin-foil artifact because it is less dense than t-ZrO/sub 2/, but more dense than m-ZrO/sub 2/. In some very thin grains, the t → m transformation was thermoelastic. Furthermore, a mottled structure often occurred just before the t → m or t → o transformation, which is attributed to surface transformation. Aside from the lath formation, the observed transformation modes are a result of the reduced constraints in thin foils

  16. Release studies of a thin foil tantalum target for the production of short-lived radioactive nuclei

    CERN Document Server

    Bennett, J R J; Drumm, P V; Lettry, Jacques; Nilsson, T; Catherall, R; Jonsson, O C; Ravn, H L; Simon, H

    2002-01-01

    Measurements have been made at ISOLDE, of the release curves and yields of radioactive beams of lithium, sodium and beryllium from a target constructed from 2 $\\mu$m thick foils. The release curves have been analysed by fitting to a mathematical model to determine the coefficients of diffusion of the particles in the foils and effusion through the target and ionizer at several temperatures. Through a better understanding of the rate of transport of the particles, it is possible to design targets and ionizers with improved yields. This is most important for the rare, short-lived isotopes in which there is considerable interest for physics experiments. This target has demonstrated large increases in the yields of $^{11}$Li and $^{12}$Be, in agreement with the predictions of the model. (11 refs).

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

    Energy Technology Data Exchange (ETDEWEB)

    Smitherman, D.P.

    1998-04-01

    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}m 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.

  18. Field emission response from multi-walled carbon nanotubes grown on electrochemically engineered copper foil

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Amit Kumar; Jain, Vaibhav [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Saini, Krishna [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Lahiri, Indranil, E-mail: indrafmt@iitr.ac.in [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India)

    2017-02-01

    Exciting properties of carbon nanotube has proven it to be a promising candidate for field emission applications, if its processing cost can be reduced effectively. In this research, a new electrochemical technique is proposed for growing carbon nanotubes in selective areas by thermal chemical vapour deposition. In this process, electrochemical processing is used to create localized pits and deposition of catalysts, which act as roots to support growth and alignment of the CNTs on copper substrate. CNTs grown thus were characterized and studied using scanning electron microscope, transmission electron microscope and Raman spectroscopy, elucidating presence of multiwall carbon nanotubes (MWCNT). These CNT emitters have comparatively lower turn-on field and higher field enhancement factor. - Highlights: • Electrochemical pitting for localized carbon nanotube growth is proposed. • Electrochemical pitting method shows patterning effect on the substrate. • Size and density of pits depend on voltage, pH and temperature. • CNTs thus grown shows good field emission response.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Stefan Knobelspies

    2018-01-01

    Full Text Available 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.

  1. Laser polarization dependence of proton emission from a thin foil target irradiated by a 70 fs, intense laser pulse

    International Nuclear Information System (INIS)

    Fukumi, A.; Nishiuchi, M.; Daido, H.; Li, Z.; Sagisaka, A.; Ogura, K.; Orimo, S.; Kado, M.; Hayashi, Y.; Mori, M.; Bulanov, S.V.; Esirkepov, T.; Nemoto, K.; Oishi, Y.; Nayuki, T.; Fujii, T.; Noda, A.; Nakamura, S.

    2005-01-01

    A study of proton emission from a 3-μm-thick Ta foil target irradiated by p-, s-, and circularly polarized laser pulses with respect to the target plane has been carried out. Protons with energies up to 880 keV were observed in the target normal direction under the irradiation by the p-polarized laser pulse, which yielded the highest efficiency for proton emission. In contrast, s- and circularly polarized laser pulses gave the maximum energies of 610 and 680 keV, respectively. The difference in the maximum energy between the p- and s-polarized cases was associated with the difference between the sheath fields estimated from electron spectra

  2. The use of the foil technique for the elimination of charging, and for beam monitoring in microbeam analysis of thick insulating samples

    International Nuclear Information System (INIS)

    Chaudhri, M.A.; Melbourne Univ., Austin

    1982-01-01

    It has been demonstrated that the 'thin-foil-technique' for the elimination of charging and accurate beam current/charge measurement, first developed by us, can also be conveniently applied to microbeam analysis of thick insulating samples. We have calculated the spatial broadening of proton microbeams of 1-20 MeV energies at the target, due to thin carbon foils of different thicknesses ranging from 10-40 μg/cm 2 placed either 2 or 5 mm in front of the target by using Moliere's theory of multiple scattering. The results show that at higher proton energies there is very little broadening of the incident beam even from thicker foils. But for lower energy protons (1 and 2 MeV) this broadening or worsening of the spatial resolution is relatively larger, especially from thicker foils. However, we have further shown that, even at these energies, the beam broadening can be minimized to acceptable limits by selecting a suitable thickness of carbon foil and placing it as close to the insulating target as possible. A comprehensive table is provided, which would help in selecting the most suitable carbon-foil thickness and the distance in front of the target where this foil should be placed, for microprobe application requiring different beam spots and proton energies. The advantages of this foil technique are described. (orig.)

  3. Equilibrium and non-equilibrium charge-state distributions of 2.0 MeV/u carbon ions passing through carbon foils

    International Nuclear Information System (INIS)

    Imai, M.; Sataka, M.; Matsuda, M.; Okayasu, S.; Kawatsura, K.; Takahiro, K.; Komaki, K.; Shibata, H.; Nishio, K.

    2015-01-01

    Both equilibrium and non-equilibrium charge-state distributions were studied experimentally for 2.0 MeV/u carbon ions after passing through carbon foils. Measured charge-state distribution established the equilibrium at a target thickness of 10 μg/cm 2 and this remained unchanged until a maximum target thickness of 98 μg/cm 2 . The equilibrium charge-state distribution, the equilibrium mean charge-state, and the width and skewness of the equilibrium distribution were compared with predictions using existing semi-empirical formulae as well as simulation results, including the ETACHA code. It was found that charge-state distributions, mean charge states, and distribution widths for C 2+ , C 3+ , and C 4+ incident ions merged into quasi-equilibrium values at a target thickness of 5.7 μg/cm 2 in the pre-equilibrium region and evolved simultaneously to the ‘real equilibrium’ values for all of the initial charge states, including C 5+ and C 6+ ions, as previously demonstrated for sulfur projectile ions at the same velocity (Imai et al., 2009). Two kinds of simulation, ETACHA and solution of rate equations taking only single electron transfers into account, were used, and both of them reproduced the measured charge evolution qualitatively. The quasi-equilibrium behavior could be reproduced with the ETACHA code, but not with solution of elementary rate equations

  4. THIN DIAMOND FILMS FOR SNS H INJECTIONS STRIPPING

    International Nuclear Information System (INIS)

    SHAW, R.W.; HERR, A.D.; FEIGERLE, C.S.; CUTLER, R.J.; LIAW, C.J.; LEE, Y.Y.

    2004-01-01

    We have investigated the preparation and testing of thin diamond foils for use in stripping the SNS H - Linac beam. A long useful lifetime for these foils is desirable to improve operational efficiency. Preliminary data presented at PAC 2001 indicated that diamond foils were superior to conventional evaporated carbon foils, exhibiting lifetimes approximately five-fold longer [1]. That work employed a fully supported diamond foil, a format that is not acceptable for the SNS application; at least two edges of the approximately 1 x 1 cm foils must be free standing to allow for beam rastering. Residual stress in a chemical vapor deposited (CVD) diamond foil results in film distortion (scrolling) when the film is released from its silicon growth substrate. We have attacked this problem by initially patterning the surface of CVD growth substrates with a 50 or 100 line/inch trapezoidal grating, followed by conformal diamond film growth on the patterned substrate. Then removal of the substrate by chemical etching produced a foil that possessed improved mechanical integrity due to its corrugation. The high nucleation density required to grow continuous, pinhole free diamond foils of the desired thickness (1 (micro)m, 350 (micro)g/cm 2 ) was achieved by a combination of substrate surface scratching and seeding. A variety of diamond foils have been tested using the BNL 750 keV Radio Frequency Quadrupole H - beam to simulate energy loss in the SNS. Those include flat, corrugated, microcrystalline, and nanocrystalline foils. Foil lifetimes are reported

  5. Energy loss measurements of {sup 63}Cu, {sup 28}Si and {sup 27}Al heavy ions crossing thin Polyvinylchloride (PVC) foil

    Energy Technology Data Exchange (ETDEWEB)

    Dib, A.; Ammi, H. [Centre de Recherche Nucléaire d’Alger, 2 Bd. Frantz Fanon, B.P. 399, Alger-Gare, Algiers (Algeria); Guesmia, A., E-mail: guesmia@tlabs.ac.za [Departement de physique, Faculté des Sciences, Université Saad Dahlab, B. P. 270, Route de Soumaa, Blida (Algeria); Departement de physique, Faculté des Sciences, Université M’hamed Bougara, Boumerdes (Algeria); iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Msimanga, M. [Department of Physics, Arcadia Campus, Tshwane University of Technology, P. Bag X680, Pretoria (South Africa); Mammeri, S. [Centre de Recherche Nucléaire d’Alger, 2 Bd. Frantz Fanon, B.P. 399, Alger-Gare, Algiers (Algeria); Hedibel, M. [Departement de physique, Faculté des Sciences, Université M’hamed Bougara, Boumerdes (Algeria); Guedioura, B. [Centre de Recherche Nucléaire de Draria, B.P. 43, Sebala-Draria, Algiers (Algeria); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, CPUT, P.O. Box 1906, Bellville 7535 (South Africa)

    2015-11-15

    Experimental stopping data of, {sup 63}Cu, {sup 28}Si and {sup 27}Al heavy ions in thin Polyvinylchloride (H{sub 3}C{sub 2}Cl{sub 1}) foil have been obtained over the 0.045–0.50 MeV/nucleon energy range. The measured energy losses were carried out by Heavy Ion Elastic Recoil Detection Analysis (HI-ERDA) technique coupled with time of flight (ToF) spectrometer. A continuous stopping power data obtained in this work are well fitted by our proposed semi-empirical formula and the results are compared to those calculated by LSS formula or generated by SRIM-2013 and MSTAR predictions. Calculations using our formula agree well with the obtained experimental stopping powers, while the LSS formula underestimates the experimental data in the whole investigated energy range. In this work a simple expression for electronic stopping power of heavy ions at low energy in solid targets is introduced. This formula is based on the Firsov and Lindhard–Sharff stopping power models with a small modification made to the original expression, by incorporating the effective charge of moving ions concept and with exponential fit function.

  6. Infrared analysis of thin films amorphous, hydrogenated carbon on silicon

    CERN Document Server

    Jacob, W; Schwarz-Selinger, T

    2000-01-01

    The infrared analysis of thin films on a thick substrate is discussed using the example of plasma-deposited, amorphous, hydrogenated carbon layers (a-C:H) on silicon substrates. The framework for the optical analysis of thin films is presented. The main characteristic of thin film optics is the occurrence of interference effects due to the coherent superposition of light multiply reflected at the various internal and external interfaces of the optical system. These interference effects lead to a sinusoidal variation of the transmitted and reflected intensity. As a consequence, the Lambert-Beer law is not applicable for the determination of the absorption coefficient of thin films. Furthermore, observable changes of the transmission and reflection spectra occur in the vicinity of strong absorption bands due to the Kramers-Kronig relation. For a sound data evaluation these effects have to be included in the analysis. To be able to extract the full information contained in a measured optical thin film spectrum, ...

  7. Gettering of carbon dioxide by erbium thin films

    International Nuclear Information System (INIS)

    Mehrhoff, T.K.

    1980-01-01

    The interaction of carbon dioxide and erbium thin films is characterized for temperatures in the region of 300 to 900 0 C and partial pressure of carbon dioxide near 5 x 10 -7 Torr. Dynamic film pumping speeds were measured against a mercury diffusion pump of known pumping speed and conductance. A quadrupole mass spectrometer was used to monitor the carbon dioxide flow which originated from a calibrated leak in the 10 -6 standard cm 3 /s range. Data reduction was via a dedicated minicomputer with associated printer/plotter. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C. The reaction was preceded by the desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface

  8. The carbonization of thin polyaniline films

    Czech Academy of Sciences Publication Activity Database

    Morávková, Zuzana; Trchová, Miroslava; Exnerová, Milena; Stejskal, Jaroslav

    2012-01-01

    Roč. 520, č. 19 (2012), s. 6088-6094 ISSN 0040-6090 R&D Projects: GA AV ČR IAA400500905; GA AV ČR IAA100500902; GA ČR GAP205/12/0911 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : polyaniline * thin films * infrared spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.604, year: 2012

  9. Multiplicity of secondary electrons emitted by carbon thin targets by impact of H0, H2+ and H3+ projectiles at MeV energies

    International Nuclear Information System (INIS)

    Vidovic, Zvonimir

    1997-01-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25 - 2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. Phenomenological and theoretical descriptions as well as a summary of the main theoretical models are the subjects of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of the thin carbon foils crossed by an energetic projectile is described in the chapter two. In this chapter there are also presented the method and the algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H 0 atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of the ions with solids. The role of the proximity of the protons, molecular ions fragments, upon the amplitude of these collected effects is evidenced from the study of the statistics of forward emission. The experiments allowed us to shed light on various aspects of atom and polyatomic ion interactions with solid surfaces. (author)

  10. Gettering of carbon dioxide by erbium thin films

    International Nuclear Information System (INIS)

    Mehrhoff, T.K.

    1980-01-01

    The interaction of carbon dioxide and erbium thin films is characterized at 300 to 900 0 C and 5 x 10 -7 torr. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C, preceded by desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface. The sticking coefficients were plotted as a function of Langmuirs of carbon dioxide exposure. Between 400 and 600 0 C, the length of the exposure was found to be more important than the temperature of the exposure in determining the sticking coefficient. Some evolution of carbon monoxide was noted particularly in the 400 to 500 0 C region. An 80% conversion of carbon dioxide to carbon monoxide was measured at 500 0 C. The film pumping speeds were compared with published vapor pressure data for erbium. This comparison indicated that a significant portion of the pumping action observed at temperatures of 800 0 C and above was due to evaporation of erbium metal

  11. Temperature dependence of the beam-foil interaction

    International Nuclear Information System (INIS)

    Gay, T.J.; Berry, H.G.

    1978-01-01

    The beam energy dependence between 50 and 200 keV of the linear polarization fraction (M/I) of the 2s 1 S--3p 1 P, 5016 A transition in He I on temperature was measured. The thin carbon exciter foils were heated externally by nichrome resistance elements. The measurements of Hight et al. are duplicated; the energy and current dependences are the same for corresponding between beam heating and external heating. It was also observed that γ, the number of slow secondary electrons produced per incident ion, decreases with increasing foil temperature. These two effects, in conjunction, offer a plausible explanation for the variation of polarization with beam current density. 5 figures

  12. Carbon Nanotube Thin Film Transistors for Flat Panel Display Application.

    Science.gov (United States)

    Liang, Xuelei; Xia, Jiye; Dong, Guodong; Tian, Boyuan; Peng, Lianmao

    2016-12-01

    Carbon nanotubes (CNTs) are promising materials for both high performance transistors for high speed computing and thin film transistors for macroelectronics, which can provide more functions at low cost. Among macroelectronics applications, carbon nanotube thin film transistors (CNT-TFT) are expected to be used soon for backplanes in flat panel displays (FPDs) due to their superior performance. In this paper, we review the challenges of CNT-TFT technology for FPD applications. The device performance of state-of-the-art CNT-TFTs are compared with the requirements of TFTs for FPDs. Compatibility of the fabrication processes of CNT-TFTs and current TFT technologies are critically examined. Though CNT-TFT technology is not yet ready for backplane production line of FPDs, the challenges can be overcome by close collaboration between research institutes and FPD manufacturers in the short term.

  13. Low-energy foil aberration corrector

    International Nuclear Information System (INIS)

    Aken, R.H. van; Hagen, C.W.; Barth, J.E.; Kruit, P.

    2002-01-01

    A spherical and chromatic aberration corrector for electron microscopes is proposed, consisting of a thin foil sandwiched between two apertures. The electrons are retarded at the foil to almost zero energy, so that they can travel ballistically through the foil. It is shown that such a low-voltage corrector has a negative spherical aberration for not too large distances between aperture and foil, as well as a negative chromatic aberration. For various distances the third- and fifth-order spherical aberration coefficients and the first- and second-order chromatic aberration coefficients are calculated using ray tracing. Provided that the foils have sufficient electron transmission the corrector is able to correct the third-order spherical aberration and the first-order chromatic aberration of a typical low-voltage scanning electron microscope. Preliminary results show that the fifth-order spherical aberration and the second-order chromatic aberration can be kept sufficiently low

  14. Spallation Neutron Source SNS Diamond Stripper Foil Development

    International Nuclear Information System (INIS)

    Shaw, Robert W.; Plum, Michael A.; Wilson, Leslie L.; Feigerle, Charles S.; Borden, Michael J.; Irie, Y.; Sugai, I.; Takagi, A.

    2007-01-01

    Diamond stripping foils are under development for the SNS. Freestanding, flat 300 to 500 (micro)g/cm 2 foils as large as 17 x 25 mm 2 have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 15 (micro)C of protons, approximately 64% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 C of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (640 keV H - ) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

  15. Infrared analysis of thin films: amorphous, hydrogenated carbon on silicon

    International Nuclear Information System (INIS)

    Jacob, Wolfgang; Keudell, Achim von; Schwarz-Selinger, Thomas

    2000-01-01

    The infrared analysis of thin films on a thick substrate is discussed using the example of plasma-deposited, amorphous, hydrogenated carbon layers (a-C:H) on silicon substrates. The framework for the optical analysis of thin films is presented. The main characteristic of thin film optics is the occurrence of interference effects due to the coherent superposition of light multiply reflected at the various internal and external interfaces of the optical system. These interference effects lead to a sinusoidal variation of the transmitted and reflected intensity. As a consequence, the Lambert-Beer law is not applicable for the determination of the absorption coefficient of thin films. Furthermore, observable changes of the transmission and reflection spectra occur in the vicinity of strong absorption bands due to the Kramers-Kronig relation. For a sound data evaluation these effects have to be included in the analysis. To be able to extract the full information contained in a measured optical thin film spectrum, an experimentally measured spectrum has to be simulated using the full formalism including the Kramers-Kronig relation. Infrared absorption spectra and the resulting k spectra in the range of the CH vibrational bands around 3000 cm -1 are presented for a variety of a-C:H layers. The shape and the total intensity of the peak are quite sensitive to the film structure. Soft, polymerlike hydrocarbon layers are characterized by a well structured, intense IR absorption band, while hard, amorphous, hydrogenated carbon layers exhibit a structureless, broad IR absorption band with relative low intensity. The k spectra of the CH vibrational bands can be considered as fingerprint for the type of a-C:H film. (author)

  16. Collodion-reinforcement and plasma-cleaning of target foils

    Science.gov (United States)

    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.

  17. Collodion-reinforcement and plasma-cleaning of target foils

    International Nuclear Information System (INIS)

    Stoner, John O.

    2002-01-01

    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

  18. Effect of length of thinning area on the failure behavior of carbon steel pipe containing a defect of wall thinning

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Park, Chi Yong

    2003-01-01

    The present study performed pipe failure tests using 102 mm-Sch. 80 carbon steel pipe with various simulated wall thinning defects, to investigate the effect of axial length of wall thinning and internal pressure on the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The tests were conducted under loading conditions of four-point bending with and without internal pressure. The results showed that a failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Both load carrying capability (LCC) and deformation capability (DC) were depended on stress type in the thinning area and dimensions of thinning defect. For applying tensile stress to the thinned area, the dependence of LCC on the axial length of wall thinning was determined by circumferential thinning angle, and the DC was proportionally increased with increase in axial length of wall thinning regardless of the circumferential angle. For applying compressive stress to thinned area, however, the LCC was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area

  19. Applications of thin carbon coatings and films in injection molding

    Science.gov (United States)

    Cabrera, Eusebio Duarte

    In this research, the technical feasibility of two novel applications of thin carbon coatings is demonstrated. The first application consists of using thin carbon coatings on molds for molding ultra-thin plastic parts (graphene coating with carbide bonding to the mold surface. The coating resulted in a significant decrease of surface friction and consequently easiness of flow when compared to their uncoated counterparts. Thermoplastic polymers and their composites are a very attractive alternative but are hindered by the non-conductive nature of polymers. There are two general approaches used to date to achieve EMI shielding for plastic products. One is to spray a conductive metal coating onto the plastic surface forming a layer that must maintain its shielding effectiveness (SE), and its adhesion to the plastic throughout the expected life of the product. However, metal coatings add undesirable weight and tend to corrode over time. Furthermore, scratching the coating may create shielding failure; therefore, a protective topcoat may be required. The other approach is to use polymer composites filled with conductive fillers such as carbon black (CB), carbon nanofiber (CNF), and carbon nanotube (CNT). While conductive fillers may increase the electrical conductivity of polymer composites, the loading of such fillers often cannot reach a high level (painting using carbon black (CB). Such process can also be applied to injection molding for creating a top conductive layer. Increasing the amount of CB will increase the surface conductivity of the coated part, thus improving the paint transfer efficiency. However the CB levels needed to achieve the conductivity levels required for achieving EMI shielding would make the coating viscosity too large for proper coating. Nanopaper based composites are excellent candidates for EMI shielding because of the nanopaper's high concentration of carbon nanofibers (CNFs) (~2 wt% to 10 wt% depending on nanopaper/thermoplastic thickness

  20. The hydrogen and oxygen content of self-supporting carbon foils prepared by dc glow discharge in ethylene

    International Nuclear Information System (INIS)

    Tait, N.R.S.; Tolfree, D.W.L.; John, P.; Odeh, I.M.; Thomas, M.J.K.; Tricker, M.J.; Wilson, J.J.B.; England, J.B.A.; Newton, D.

    1980-01-01

    The hydrogen and oxygen content of self-supporting carbon films produced by dc glow discharge have been determined using a precise method involving the elastic scattering of 25 MeV α-particles. The number of carbon-hydrogen bonds has been determined for similar samples using infrared spectroscopy. The results are compared with those for samples made by the carbon arc process. Assuming that the glow discharge carbon contains graphitic regions surrounded by amorphous tetrahedrally bonded material to which hydrogen can attach, a simple estimate is made of the relative numbers of carbon atoms in the two forms. (orig.)

  1. Optical properties of diamond like carbon nanocomposite thin films

    Science.gov (United States)

    Alam, Md Shahbaz; Mukherjee, Nillohit; Ahmed, Sk. Faruque

    2018-05-01

    The optical properties of silicon incorporated diamond like carbon (Si-DLC) nanocomposite thin films have been reported. The Si-DLC nanocomposite thin film deposited on glass and silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process. Fourier transformed infrared spectroscopic analysis revealed the presence of different bonding within the deposited films and deconvolution of FTIR spectra gives the chemical composition i.e., sp3/sp2 ratio in the films. Optical band gap calculated from transmittance spectra increased from 0.98 to 2.21 eV with a variation of silicon concentration from 0 to 15.4 at. %. Due to change in electronic structure by Si incorporation, the Si-DLC film showed a broad photoluminescence (PL) peak centered at 467 nm, i.e., in the visible range and its intensity was found to increase monotonically with at. % of Si.

  2. Printable Thin Film Supercapacitors Using Single-Walled Carbon Nanotubes

    KAUST Repository

    Kaempgen, Martti

    2009-05-13

    Thin film supercapacitors were fabricated using printable materials to make flexible devices on plastic. The active electrodes were made from sprayed networks of single-walled carbon nanotubes (SWCNTs) serving as both electrodes and charge collectors. Using a printable aqueous gel electrolyte as well as an organic liquid electrolyte, the performances of the devices show very high energy and power densities (6 W h/kg for both electrolytes and 23 and 70 kW/kg for aqueous gel electrolyte and organic electrolyte, respectively) which is comparable to performance in other SWCNT-based supercapacitor devices fabricated using different methods. The results underline the potential of printable thin film supercapacitors. The simplified architecture and the sole use of printable materials may lead to a new class of entirely printable charge storage devices allowing for full integration with the emerging field of printed electronics. © 2009 American Chemical Society.

  3. The theoretical and empirical basis for understanding the impact of thinning on carbon stores in forests

    Science.gov (United States)

    Mark E. Harmon

    2013-01-01

    Th inning of forests has been proposed as a means to increase the carbon stores of forests. Th e justifi cation often offered is that thinning increases stand productivity, which in turn leads to higher carbon stores. While thinning of forests clearly increases the growth of residual trees and increases the amount of harvested carbon compared to an unthinned stand,...

  4. Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

    Directory of Open Access Journals (Sweden)

    O. V. Denisov

    2015-01-01

    Full Text Available Polymer composite materials (CM are widely used in creation of large space constructions, especially reflectors of space antennas. Composite materials should provide high level of specific stiffness and strength for space structures. Thermal conductivity in reinforcement plane is a significant factor in case of irregular heating space antennas. Nowadays, data on CM reinforcement plane thermal conductivity are limited and existing methods of its defining are imperfect. Basically, traditional methods allow us to define thermal conductivity in perpendicular direction towards the reinforcement plane on the samples of round or rectangular plate. In addition, the thickness of standard samples is larger than space antenna thickness. Consequently, new methods are required. Method of contact heating, which was developed by BMSTU specialists with long hollow carbon beam, could be a perspective way. This article is devoted to the experimental method of contact heating on the thin carbon plates.Thermal tests were supposed to provide a non-stationary temperature field with a gradient being co-directional with the plane reinforcement in the material sample. Experiments were conducted in vacuum chamber to prevent unstructured convection. Experimental thermo-grams processing were calculated by 1-d thermal model for a thin plate. Influence of uncertainty of experimental parameters, such as (radiation emission coefficients of sample surface, glue, temperature sensors and uncertainty of sensors placement on the result of defined thermal conductivity has been estimated. New data on the thermal conductivity in reinforcement plane were obtained within 295 - 375 K temperature range, which can be used to design and develop reflectors of precision space antennas. In the future it is expedient to conduct tests of thin-wall plates from carbon fiber-reinforced plastic in wide temperature range, especially in the low-range temperatures.

  5. New intensifier foils in roentgenologic diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, H K; Schulze, B

    1981-09-01

    The main components of the foils are the carrier layer and the luminescent layer, which are in direct contact through an adhesive layer. Carrier layer and adhesive layer absorb and reflect parts of the light. In order to reduce this effect, modern foils are slightly dyed, mostly in the complementary colour of the emitted light. The luminescent layer is attached to the carrier layer by means of a binder. The mean binder content of the luminescent layer is about 10% of the weight of the luminescent material. The particle or crystal range between 5 and 10 ..mu..m. The luminescent layer thickness varies between 0.1 and 0.5 mm, according to the intensification. The imposing with luminescents consequently increases from 20 up to 100 mg/cm/sup 2/. In most cases the luminescent layer is protected by a thin layer (10 to 20 ..mu..m thick) of a very resistant and well-transparent synthetic resin. A foil combination consists of a front and a rear foil, the rear foil often providing a higher degree of intensification than the front foil. Foil quality is mainly defined by the intensification factor, quality on its part is characterized by the modulation transmission function and by the particle structure of the luminescent layer. Quality indicators are also the durability of the foils and the steadiness of the crystal arrangement in the luminescent layer. The representation quality is deteriorated also by the irregular blackening of the roentgen film, resulting from the statistic fluctuations of the roentgen quantums, which are absorbed in the luminescent layer. This unfavourable feature, termed quantum noise, increases with decreasing irradiation intensity, with increasing film gradation, and with increasing sensivity of the film-foil-system. Moreover, an optimal image quality is only possible when film and foil are in good contact conditions (in the cassette).

  6. Investigation of the Emissivity and Suitability of a Carbon Thin Film for Terahertz Absorbers

    Science.gov (United States)

    2016-06-01

    however, the understanding that the introduction of a carbon thin film could reduce signal loss and will result in a change in thermal fluctuations is...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS INVESTIGATION OF THE EMISSIVITY AND SUITABILITY OF A CARBON THIN FILM FOR TERAHERTZ ABSORBERS...TITLE AND SUBTITLE INVESTIGATION OF THE EMISSIVITY AND SUITABILITY OF A CARBON THIN FILM FOR TERAHERTZ ABSORBERS 5. FUNDING NUMBERS 6. AUTHOR(S) Naomi C

  7. Transmission Electron Microscopy of Amorphous Tandem Thin-Film Silicon Modules Produced by A Roll-to-Roll Process on Plastic Foil

    DEFF Research Database (Denmark)

    Couty, P.; Duchamp, Martial; Söderström, K.

    2011-01-01

    An improvement of the photo-current is expected when amorphous silicon solar cells are grown on a ZnO texture. A full understanding of the relationship between cell structure and electrical performance is essential for the rapid development of high efficiency VHF-tandem cells on textured substrates...... a control-lost of shape fidelity is used to smooth the texture and make it compatible with subsequent layer growth. Then, we present the electrical performances of the most promising reference solar cell single junction which was obtained on a roll-to-roll foil. Finally, a tandem amorphous/amorphous Si....... At first, we present the systematic study where amorphous cells are grown on ZnO based textures. For varying the texture, the same original master LPCVD ZnO was successively transferred to nickel molds and finally transferred to the plastic foil by roll-to-roll process. From TEM images, we show how...

  8. Foil changing apparatus

    International Nuclear Information System (INIS)

    Crist, C.E.; Ives, H.C.; Leifeste, G.T.; Miller, R.B.

    1988-01-01

    A self-contained foil changer apparatus for replenishing foil material across the path of a high energy particle beam is described comprising: a cylindrical hermetically sealed housing comprising an end plate having an aperture defining a beam passageway therethrough; foil supply means disposed inside the housing for storing a foil web and supporting a portion of the web across the beam passageway to form a plane perpendicular to the beam path; a barrel assembly disposed inside the housing; web control means extending through the housing and operably connected to the foil supply means for selectively advancing the foil web to replenish a portion across the beam passageway; and barrel control means extending through the housing and operably connected to the barrel assembly for selectively moving the barrel to and from the advanced and retracted positions

  9. Hyaluronan-lecithin foils and their properties

    International Nuclear Information System (INIS)

    BiaIopiotrowicz, Tomasz; Janczuk, BronisIaw; Fiedorowicz, Maciej; Khachatryan, Gohar; Tomasik, Piotr; Bakos, Dusan

    2006-01-01

    Thin, elastic foils of good resistance to the air exposure, patented as wound healing aids, were prepared by evaporation of a blend of lecithin (L) and sodium hyaluronan (H) taken under varying proportions. The contact angle for water, glycerol, formamide, ethylene glycol and diiodomethane, was determined for these foils. The contact angle was correlated against the H:L foil composition. For all liquids but formamide the highest contact angle was noted for the H:L = 2:1 (g g -1 ) ratio. The contact angles provided estimation of the work of adhesion. At the same L:H ratio the work of adhesion was the lowest. It was suggested that lecithin cross-linked hyaluronan. Since the work of adhesion of the studied liquids was similar to that of diiodomethane, it could be concluded that almost all functional groups on the foil surface were completely blocked. Perhaps, at H:L = 2:1 (g g -1 ) a stoichiometric complex of hyaluronic acid with lecithin was formed, and polar functional groups from both reagents were involved. Foils seem to be electrostatic complexes of H with L. Foils with the H:L equal to 2:1 exhibited specific properties confirmed by the IR reflectance spectra of the foils. The thermogravimetry (TG/DTG) also revealed unique thermal behaviour confirming other specific properties of the foil of this composition. For the same ratio a thorough inspection of the scanning electron micrographs (SEM) revealed few irregularly distributed perforations of 1-2 μm in diameter seen as black points, which can be recognized as pores. Properties of the foils determined in the contact angle measurements are nicely backed by the results from thermogravimetric and scanning electron microscopic studies

  10. Process for producing molybdenum foil and collapsible tubing

    Science.gov (United States)

    Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

    1971-01-01

    Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

  11. Charging of carbon thin films in scanning and phase-plate transmission electron microscopy

    DEFF Research Database (Denmark)

    Hettler, Simon; Kano, Emi; Dries, Manuel

    2018-01-01

    A systematic study on charging of carbon thin films under intense electron-beam irradiation was performed in a transmission electron microscope to identify the underlying physics for the functionality of hole-free phase plates. Thin amorphous carbon films fabricated by different deposition techni...

  12. Preparation of diamond like carbon thin film on stainless steel and ...

    Indian Academy of Sciences (India)

    Diamond-like carbon; buffer layer; plasma CVD; surface characterization; biomedical applications. Abstract. We report the formation of a very smooth, continuous and homogeneous diamond-like carbon DLC thin coating over a bare stainless steel surface without the need for a thin Si/Cr/Ni/Mo/W/TiN/TiC interfacial layer.

  13. Thin randomly aligned hierarchical carbon nanotube arrays as ultrablack metamaterials

    Science.gov (United States)

    De Nicola, Francesco; Hines, Peter; De Crescenzi, Maurizio; Motta, Nunzio

    2017-07-01

    Ultrablack metamaterials are artificial materials able to harvest all the incident light regardless of wavelength, angle, or polarization. Here, we show the ultrablack properties of randomly aligned hierarchical carbon nanotube arrays with thicknesses below 200 nm. The thin coatings are realized by solution processing and dry-transfer deposition on different substrates. The hierarchical surface morphology of the coatings is biomimetic and provides a large effective area that improves the film optical absorption. Also, such a morphology is responsible for the moth-eye effect, which leads to the omnidirectional and polarization-independent suppression of optical reflection. The films exhibit an emissivity up to 99.36% typical of an ideal black body, resulting in the thinnest ultrablack metamaterial ever reported. Such a material may be exploited for thermal, optical, and optoelectronic devices such as heat sinks, optical shields, solar cells, light and thermal sensors, and light-emitting diodes.

  14. Vapor-phase polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) on commercial carbon coated aluminum foil as enhanced electrodes for supercapacitors

    Science.gov (United States)

    Tong, Linyue; Skorenko, Kenneth H.; Faucett, Austin C.; Boyer, Steven M.; Liu, Jian; Mativetsky, Jeffrey M.; Bernier, William E.; Jones, Wayne E.

    2015-11-01

    Laminar composite electrodes are prepared for application in supercapacitors using a catalyzed vapor-phase polymerization (VPP) of 3,4-ethylenedioxythiophene (EDOT) on the surface of commercial carbon coated aluminum foil. These highly electrically conducting polymer films provide for rapid and stable power storage per gram at room temperature. The chemical composition, surface morphology and electrical properties are characterized by Raman spectroscopy, scanning electron microscopy (SEM), and conducting atomic force microscopy (C-AFM). A series of electrical measurements including cyclic voltammetry (CV), charge-discharge (CD) and electrochemical impedance spectroscopy are also used to evaluate electrical performance. The processing temperature of VPP shows a significant effect on PEDOT morphology, the degree of orientation and its electrical properties. The relatively high temperature leads to high specific area and large conductive domains of PEDOT layer which benefits the capacitive behavior greatly according to the data presented. Since the substrate is already highly conductive, the PEDOT based composite can be used as electrode materials directly without adding current collector. By this simple and efficient process, PEDOT based composites exhibit specific capacitance up to 134 F g-1 with the polymerization temperature of 110 °C.

  15. Charge-changing processes of heavy ions in matter. Non-equilibrium charge state distribution of sulfur ions after carbon foil penetration

    International Nuclear Information System (INIS)

    Imai, Makoto; Shibata, Hiromi; Sataka, Masao; Sugai, Hiroyuki; Nishio, Katsuhisa; Sugiyama, Koji; Komaki, Ken-ichiro

    2005-01-01

    Charge state distributions of 2.0 MeV/u (64 MeV) sulfur ions of various initial charge states (6+, 10+, 11+, 13+) after passing through 0.9, 1.1, 1.5, 2.0, 3.0, 4.7, 6.9 and 10 μg/cm 2 carbon foils have been studied experimentally using the heavy ion spectrometer 'ENMA'. Measured charge state distributions do not flat off to establish equilibrium within the measured thickness, proving to be the first systematic measurement of non-equilibrium charge state distribution using solid target at this energy range. The mean charge states and their distribution widths almost saturate to 12.4 and 1.03, respectively, for all initial charge states examined. Calculation with ETACHA code, developed by Rozet et al. [Nucl. Instr. and Meth. B 107 (1996) 67], is employed, although the present impact energy is lower than the assumed energy region for this code. It was also confirmed that a certain portion of 16 O q+ (q=3, 4, 7) beam is included in 32 S q+ (q=6, 8, 14) beam provided from the Tandem Accelerator, which originates in the Negative Ion Source forming O 2 - . (author)

  16. Investigation of electrically exploded large area foil for current switching

    International Nuclear Information System (INIS)

    Chernyshev, V.K.; Boyko, A.M.; Kostyukov, V.N.; Kuzyaev, A.I.; Kulagin, A.A.; Mamyshev, V.I.; Mezhevov, A.B.; Nechaev, A.I.; Petrukhin, A.A.; Protasov, M.S.; Shevtsov, V.I.; Yakubov, V.B.

    1990-01-01

    The possibility of microsecond ∼40 MA current switching from EMG into a quasiconstant inductive load by an electrically exploded foil is investigated. The copper foil of large area, S ∼ 10 4 cm 2 , was placed between thin-walled insulators into a coaxial transmission line (TL). This paper shows a conceptual device scheme. To feed a foil opening switch (FOS), a disc explosive magnetic generator (DEMG) with 20 μs current rise time was employed. An inductive coaxial load was connected to a FOS at a moment, that was close to the foil vaporization start by means of an axisymmetric explosive current commutator (ECC)

  17. Carbon and water fluxes from ponderosa pine forests disturbed by wildfire and thinning.

    Science.gov (United States)

    Dore, S; Kolb, T E; Montes-Helu, M; Eckert, S E; Sullivan, B W; Hungate, B A; Kaye, J P; Hart, S C; Koch, G W; Finkral, A

    2010-04-01

    Disturbances alter ecosystem carbon dynamics, often by reducing carbon uptake and stocks. We compared the impact of two types of disturbances that represent the most likely future conditions of currently dense ponderosa pine forests of the southwestern United States: (1) high-intensity fire and (2) thinning, designed to reduce fire intensity. High-severity fire had a larger impact on ecosystem carbon uptake and storage than thinning. Total ecosystem carbon was 42% lower at the intensely burned site, 10 years after burning, than at the undisturbed site. Eddy covariance measurements over two years showed that the burned site was a net annual source of carbon to the atmosphere whereas the undisturbed site was a sink. Net primary production (NPP), evapotranspiration (ET), and water use efficiency were lower at the burned site than at the undisturbed site. In contrast, thinning decreased total ecosystem carbon by 18%, and changed the site from a carbon sink to a source in the first posttreatment year. Thinning also decreased ET, reduced the limitation of drought on carbon uptake during summer, and did not change water use efficiency. Both disturbances reduced ecosystem carbon uptake by decreasing gross primary production (55% by burning, 30% by thinning) more than total ecosystem respiration (TER; 33-47% by burning, 18% by thinning), and increased the contribution of soil carbon dioxide efflux to TER. The relationship between TER and temperature was not affected by either disturbance. Efforts to accurately estimate regional carbon budgets should consider impacts on carbon dynamics of both large disturbances, such as high-intensity fire, and the partial disturbance of thinning that is often used to prevent intense burning. Our results show that thinned forests of ponderosa pine in the southwestern United States are a desirable alternative to intensively burned forests to maintain carbon stocks and primary production.

  18. Recovery of ponderosa pine ecosystem carbon and water fluxes from thinning and stand-replacing fire.

    Science.gov (United States)

    Dore, Sabina; Montes-Helu, Mario; Hart, Stephen C; Hungate, Bruce A; Koch, George W; Moon, John B; Finkral, Alex J; Kolb, Thomas E

    2012-10-01

    Carbon uptake by forests is a major sink in the global carbon cycle, helping buffer the rising concentration of CO 2 in the atmosphere, yet the potential for future carbon uptake by forests is uncertain. Climate warming and drought can reduce forest carbon uptake by reducing photosynthesis, increasing respiration, and by increasing the frequency and intensity of wildfires, leading to large releases of stored carbon. Five years of eddy covariance measurements in a ponderosa pine (Pinus ponderosa)-dominated ecosystem in northern Arizona showed that an intense wildfire that converted forest into sparse grassland shifted site carbon balance from sink to source for at least 15 years after burning. In contrast, recovery of carbon sink strength after thinning, a management practice used to reduce the likelihood of intense wildfires, was rapid. Comparisons between an undisturbed-control site and an experimentally thinned site showed that thinning reduced carbon sink strength only for the first two posttreatment years. In the third and fourth posttreatment years, annual carbon sink strength of the thinned site was higher than the undisturbed site because thinning reduced aridity and drought limitation to carbon uptake. As a result, annual maximum gross primary production occurred when temperature was 3 °C higher at the thinned site compared with the undisturbed site. The severe fire consistently reduced annual evapotranspiration (range of 12-30%), whereas effects of thinning were smaller and transient, and could not be detected in the fourth year after thinning. Our results show large and persistent effects of intense fire and minor and short-lived effects of thinning on southwestern ponderosa pine ecosystem carbon and water exchanges. © 2012 Blackwell Publishing Ltd.

  19. Role of carbon in boron suboxide thin films

    International Nuclear Information System (INIS)

    Music, Denis; Kugler, Veronika M.; Czigany, Zsolt; Flink, Axel; Werner, Oskar; Schneider, Jochen M.; Hultman, Lars; Helmersson, Ulf

    2003-01-01

    Boron suboxide thin films, with controlled carbon content, were grown by rf dual magnetron sputtering of boron and carbon targets in an argon-oxygen atmosphere. Film composition, structure, mechanical, and electrical properties were evaluated with x-ray photoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, nanoindentation, and high-frequency capacitance-voltage measurements. X-ray amorphous B-O-C films (O/B=0.02) showed an increase in density from 2.0 to 2.4 g/cm 3 as C content was increased from 0 to 0.6 at. % and the film with the highest density had nanocrystalline inclusions. The density increase occurred most likely due to the formation of B-C bonds, which are shorter than B-B bonds. All measured material properties were found to depend strongly on the C content and thus film density. The elastic modulus increased from 188 to 281 GPa with the increasing C content, while the relative dielectric constant decreased from 19.2 to 0.9. Hence, B-O-C films show a potential for protective coatings and even for application in electronic and optical devices

  20. Effects of thinning on aboveground carbon sequestration by a 45-year-old eastern white pine plantation: A case study

    Science.gov (United States)

    W. Henry McNab

    2012-01-01

    Aboveground carbon sequestration by a 45-year-old plantation of eastern white pines was determined in response to thinning to three levels of residual basal area: (1) Control (no thinning), (2) light thinning to 120 feet2/acre and (3) heavy thinning to 80 feet2/acre. After 11 years carbon stocks were lowest on the heavily...

  1. Optimization of pulsed laser welding process parameters in order to attain minimum underfill and undercut defects in thin 316L stainless steel foils

    Science.gov (United States)

    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.

  2. Gas sensors boosted by two-dimensional h-BN enabled transfer on thin substrate foils: towards wearable and portable applications.

    Science.gov (United States)

    Ayari, Taha; Bishop, Chris; Jordan, Matthew B; Sundaram, Suresh; Li, Xin; Alam, Saiful; ElGmili, Youssef; Patriarche, Gilles; Voss, Paul L; Salvestrini, Jean Paul; Ougazzaden, Abdallah

    2017-11-09

    The transfer of GaN based gas sensors to foreign substrates provides a pathway to enhance sensor performance, lower the cost and extend the applications to wearable, mobile or disposable systems. The main keys to unlocking this pathway is to grow and fabricate the sensors on large h-BN surface and to transfer them to the flexible substrate without any degradation of the performances. In this work, we develop a new generation of AlGaN/GaN gas sensors with boosted performances on a low cost flexible substrate. We fabricate 2-inch wafer scale AlGaN/GaN gas sensors on sacrificial two-dimensional (2D) nano-layered h-BN without any delamination or cracks and subsequently transfer sensors to an acrylic surface on metallic foil. This technique results in a modification of relevant device properties, leading to a doubling of the sensitivity to NO 2 gas and a response time that is more than 6 times faster than before transfer. This new approach for GaN-based sensor design opens new avenues for sensor improvement via transfer to more suitable substrates, and is promising for next-generation wearable and portable opto-electronic devices.

  3. Foil changer for the Chalk River superconducting cyclotron

    International Nuclear Information System (INIS)

    Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.E.; Proulx, D.R.; Weaver, J.F.

    1985-01-01

    Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

  4. Foil changer for the Chalk River superconducting cyclotron

    International Nuclear Information System (INIS)

    Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.F.; Proulx, D.R.; Weaver, J.F.

    1985-01-01

    Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

  5. Scanning and transmission electron microscopy investigation of multiwall carbon nanotube/nickel oxide nanocomposite thin films

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2011-12-01

    Full Text Available Owing to their unique electronic and optical properties, nanocomposite thin films are widely used for converting solar radiation therapy into other conventional energy forms, such as heat and electricity. Carbon nanotube-based composites which can...

  6. Additional security features for optically variable foils

    Science.gov (United States)

    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.

  7. Beam-foil lifetimes of highly ionized silicon

    International Nuclear Information System (INIS)

    Traebert, E.; Heckmann, P.H.; Buttlar, H. v.

    1977-01-01

    Electronically excited states of Si ions are created by passing a 20 MeV Si 5+ beam through a thin carbon foil. The EUV-radiation (lambda = 13-61 nm) emitted by the beam is analyzed using a grazing-incidence spectrometer. From the decay curves, lifetimes of 24 low lying levels in Si VIII to Si XII and of the 4f and 5g levels of Si XI and Si XII are derived. Cascades from doubly excited states turn out to be an important contribution to the radiation observed. The lifetime values of this work are compared to theoretical data mainly of Wiese, Sinanoglu and Dankwort/Trefftz. Most experimental values agree with at least one of the theoretical values. The decay time 560 ps of the 2s2p 3 3 D 0 3 state of Si IX is clearly longer than the theoretical prediction (highest value 455 ps by Sinanoglu). (orig.) [de

  8. Beam-foil spectroscopy of chlorine and sulfur ions

    International Nuclear Information System (INIS)

    Frot, D.; Barchewitz, R.; Cukier, M.; Bruneau, J.

    1987-01-01

    We report on the measurement of spectra of highly stripped chlorine and sulfur ions in the energy ranges of, respectively, 2900 - 3500 eV and 2300 - 2600 eV. The spectra have been obtained after excitation of ions travelling through a thin carbon foil. X-rays emitted by the emerging beam are analysed with a Johann-type bent crystal spectrometer. The observation angle with respect to the beam axis is 54 0 . The interpretation of the spectra is performed by comparing experimental results with Multiconfiguration Dirac-Fock (MCDF) calculated energies and intensities. All the lines are interpreted by 2p - ls transitions (K α spectrum) in excited ions with, respectively, H-, He-, Li-, Be- and B-like electron structures

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

    Science.gov (United States)

    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.

  10. Method of fabricating a uranium-bearing foil

    Science.gov (United States)

    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.

  11. Magazine for handling stripping foils in a particle accelerator

    International Nuclear Information System (INIS)

    Gorka, A.J. Jr.

    1975-01-01

    Thin foils for stripping a particle beam are stored in a magazine that is operable remotely to display an individual foil, release it when it is spent, and repeat this process. The magazine is operable in the high-vacuum, high-radiation environment in the interior of a particle accelerator, and it uses the magnetic field of the accelerator to operate the display and dropping mechanism. (U.S.)

  12. Foil focusing of relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Jr., Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  13. Experiments with activated metal foils

    Energy Technology Data Exchange (ETDEWEB)

    Malati, M A [Medway and Maidstone Coll. of Tech., Chatham (UK)

    1978-09-01

    Experiments based on the activation of metal foils by slow neutron bombardment which can be used to demonstrate various aspects of artificial radioactivity are described and discussed. Suitable neutron sources and foils are considered.

  14. Monolithic exploding foil initiator

    Science.gov (United States)

    Welle, Eric J; Vianco, Paul T; Headley, Paul S; Jarrell, Jason A; Garrity, J. Emmett; Shelton, Keegan P; Marley, Stephen K

    2012-10-23

    A monolithic exploding foil initiator (EFI) or slapper detonator and the method for making the monolithic EFI wherein the exploding bridge and the dielectric from which the flyer will be generated are integrated directly onto the header. In some embodiments, the barrel is directly integrated directly onto the header.

  15. Industrial fabrication of an optical security device for document protection using plasmon resonant transmission through a thin corrugated metallic film embedded on a plastic foil

    Science.gov (United States)

    Sauvage-Vincent, Jean; Jourlin, Yves; Tonchev, Svetlen; Veillas, Colette; Claude, Pedri; Parriaux, Olivier

    2012-06-01

    Known since a long time in polymer banknotes and presented in the few years in paper banknotes, the principle of windowed documents has been currently extended to ID documents. We present an innovative solution which combines resonant transmission and Zero Order Device technologies and which is dedicated to improve windows in terms of the overt security level. With this R&D program, Hologram Industries targeted to obtain an overt visual security device that should be readily checked in transmission in the same manner as the established paper watermark. The proposed solution is based on the propagation of resonant modes in a thin continuous corrugated metallic layer embedded (encapsulated) between two dielectric layers of near equal refractive index. The mode of most interest is the Long Range Plasmon Mode. The coupling condition to the Long Range Mode is principally related to the corrugation, the metal layer thickness and the index of the two dielectric layers. If the condition of the mode excitation through the grating is fulfilled, a predetermined wavelength will be coupled to the Long Range Plasmon Mode. This mode will propagate at each metal/dielectric interface with a low loss and will concentrate the electric field inside the metal layer. This effect of coupling enables the transmission of a peak at this wavelength through the metallic layer. It defines the so called "extraordinary resonant transmission".

  16. Carbon buildup monitoring using RBS: Correlation with secondary electrons

    International Nuclear Information System (INIS)

    Aguilera, E.F.; Rosales, P.; Martinez-Quiroz, E.; Murillo, G.; Fernandez, M.C.

    2006-01-01

    The RBS technique is applied to solve the problem of on-line monitoring of the carbon deposited on a thin backed foil under ion bombardment. An iterative method is used to reliably extract quantities such as number of projectiles and target thickness in spite of beam energy changes and detector unstabilities. Experimental values for secondary electron yields are also deduced. Results are reported for the thickness variation of thin carbon foils bombarded with carbon ions of energies between 8.95 and 13 MeV. A linear correlation of this variation is found with both, the ion fluence at target and the number of secondary electrons emitted. The correlation exists even though a wide range of beam currents, beam energies and bombarding times was used during the experiment. The measured electron yields show evidence for a change in the emission process between the original foils and the deposited layer, possibly due to a texture change

  17. Chemically robust carbon nanotube–PTFE superhydrophobic thin films with enhanced ability of wear resistance

    Institute of Scientific and Technical Information of China (English)

    Kewei Wang; Pan Xiong; Xiuping Xu; Kan Wang; YanLong Li; Yufeng Zheng

    2017-01-01

    A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene (PTFE) and carbon nanotubes. The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer. Thin films with a contact angle of 154.1° ± 2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm2. The thin film is also extremely stable even under much stress conditions. To further the understanding of the enhancement of wear resistance, we investigated the formation of microsized structure and their effects. The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.

  18. Synergetic effects of thin plies and aligned carbon nanotube interlaminar reinforcement in composite laminates

    OpenAIRE

    Arteiro, Albertino; Borstnar, Gregor; Mavrogordato, Mark N.; Sinclair, Ian; Spearing, S. Mark; Camanho, Pedro P.; Cohen, Estelle; Kopp, Reed Alan; Furtado Pereira da Silva, Carolina; Ni, Xinchen; Wardle, Brian L

    2017-01-01

    Thin-ply carbon fiber laminates have exhibited superior mechanical properties, including higher initiation and ultimate strength, when compared to standard thickness plies and enable greater flexibility in laminate design. However, the increased ply count in thin-ply laminates also increases the number of ply-ply interfaces, thereby increasing the number of relatively weak and delamination-prone interlaminar regions. In this study, we report the first experimental realization of aligned carbo...

  19. Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun [Pusan National University, School of Mechanical Engineering, Busan (Korea, Republic of)

    2010-10-15

    The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

  20. Assessment of wall-thinning in carbon steel pipe by using laser-generated guided wave

    International Nuclear Information System (INIS)

    Kim, Do Yong; Cho, Youn Ho; Lee, Joon Hyun

    2010-01-01

    The objective of this research is to estimate the crack location and size of a carbon steel pipe by using a laser ultrasound guided wave for the wall thinning evaluation of an elbow. The wall thinning of the carbon steel pipe is one of the most serious problems in nuclear power plants, especially the wall thinning of the carbon steel elbow caused by Flow-Accelerated Corrosion (FAC). Therefore, a non-destructive inspection method of elbow is essential for the nuclear power plants to operate safely. The specimens used in this study were carbon steel elbows, which represented the main elements of real nuclear power plants. The shape of the wall thinning was an oval with a width of 120mm, a length of 80mm, and a depth of 5mm. The L(0,1) and L(0,2) modes variation of the ultrasound guided wave signal is obtained from the response of the laser generation/air-coupled detection ultrasonic hybrid system represent the characteristics of the defect. The trends of these characteristics and signal processing were use dto estimate the size and location of wall thinning

  1. Process for anodizing aluminum foil

    International Nuclear Information System (INIS)

    Ball, J.A.; Scott, J.W.

    1984-01-01

    In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 80 0 C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V

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

    Science.gov (United States)

    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.

  3. Physical properties of chemical vapour deposited nanostructured carbon thin films

    International Nuclear Information System (INIS)

    Mahadik, D.B.; Shinde, S.S.; Bhosale, C.H.; Rajpure, K.Y.

    2011-01-01

    Research highlights: In the present paper, nanostructured carbon films are grown using a natural precursor 'turpentine oil (C 10 H 16 )' as a carbon source in the simple thermal chemical vapour deposition method. The influence of substrate surface topography (viz. stainless steel, fluorine doped tin oxide coated quartz) and temperature on the evolution of carbon allotropes surfaces topography/microstructural and structural properties are investigated and discussed. - Abstract: A simple thermal chemical vapour deposition technique is employed for the deposition of carbon films by pyrolysing the natural precursor 'turpentine oil' on to the stainless steel (SS) and FTO coated quartz substrates at higher temperatures (700-1100 deg. C). In this work, we have studied the influence of substrate and deposition temperature on the evolution of structural and morphological properties of nanostructured carbon films. The films were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle measurements, Fourier transform infrared (FTIR) and Raman spectroscopy techniques. XRD study reveals that the films are polycrystalline exhibiting hexagonal and face-centered cubic structures on SS and FTO coated glass substrates respectively. SEM images show the porous and agglomerated surface of the films. Deposited carbon films show the hydrophobic nature. FTIR study displays C-H and O-H stretching vibration modes in the films. Raman analysis shows that, high ID/IG for FTO substrate confirms the dominance of sp 3 bonds with diamond phase and less for SS shows graphitization effect with dominant sp 2 bonds. It reveals the difference in local microstructure of carbon deposits leading to variation in contact angle and hardness, which is ascribed to difference in the packing density of carbon films, as observed also by Raman.

  4. Binder-free manganese oxide/carbon nanomaterials thin film electrode for supercapacitors.

    Science.gov (United States)

    Wang, Ning; Wu, Chuxin; Li, Jiaxin; Dong, Guofa; Guan, Lunhui

    2011-11-01

    A ternary thin film electrode was created by coating manganese oxide onto a network composed of single-walled carbon nanotubes and single-walled carbon nanohorns. The electrode exhibited a porous structure, which is a promising architecture for supercapacitors applications. The maximum specific capacitances of 357 F/g for total electrode at 1 A/g were achieved in 0.1 M Na(2)SO(4) aqueous solution.

  5. Carbon nanotube network thin-film transistors on flexible/stretchable substrates

    Science.gov (United States)

    Takei, Kuniharu; Takahashi, Toshitake; Javey, Ali

    2016-03-29

    This disclosure provides systems, methods, and apparatus for flexible thin-film transistors. In one aspect, a device includes a polymer substrate, a gate electrode disposed on the polymer substrate, a dielectric layer disposed on the gate electrode and on exposed portions of the polymer substrate, a carbon nanotube network disposed on the dielectric layer, and a source electrode and a drain electrode disposed on the carbon nanotube network.

  6. Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

    Energy Technology Data Exchange (ETDEWEB)

    Awazu, Kaoru; Yoshida, Hiroyuki [Industrial Research Inst. of Ishikawa (Japan); Watanabe, Hiroshi [Gakushuin Univ., Tokyo (Japan); Iwaki, Masaya; Guzman, L [RIKEN, Saitama (Japan)

    1992-04-15

    A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C{sub 6}H{sub 6} gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10{sup 16} ions cm{sup -2}. The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.).

  7. Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

    International Nuclear Information System (INIS)

    Awazu, Kaoru; Yoshida, Hiroyuki; Watanabe, Hiroshi; Iwaki, Masaya; Guzman, L.

    1992-01-01

    A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C 6 H 6 gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10 16 ions cm -2 . The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Prashant, E-mail: prashant@iuac.res.in; Nandi, Tapan [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    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 between 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.

  9. Etching processes of transparent carbon nanotube thin films using laser technologies

    International Nuclear Information System (INIS)

    Lin, H.K.; Lin, R.C.; Li, C.H.

    2010-01-01

    Carbon nanotubes (CNTs) have potential as a transparent conductive material with good mechanical and electrical properties. However, carbon nanotube thin film deposition and etching processes are very difficult to pattern the electrode. In this study, transparent CNT film with a binder is coated on a PET flexible substrate. The transmittance and sheet resistance of carbon nanotube film are 84% and 1000 Ω/□, respectively. The etching process of carbon nanotube film on flexible substrates was investigated using 355 nm and 1064 nm laser sources. Experimental results show that carbon nanotube film can be ablated using laser technology. With the 355 nm UV laser, the minimum etched line width was 20 μm with a low amount of recast material of the ablated sections. The optimal conditions of laser ablation were determined for carbon nanotube film.

  10. Modification of rubber surface with hydrogenated diamond-like carbon thin films

    NARCIS (Netherlands)

    Pei, Y. T.; Bui, X. L.; De Hosson, J. Th. M.; Laudon, M; Romanowicz, B

    2009-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals, by sputtering graphite targets in C(2)H(2)/Ar plasma. The wax removal and pre-deposition

  11. Flexible diamond-like carbon thin film coated on rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Yutao

    2015-01-01

    Dynamic rubber seals are the major source of friction in lubrication systems and bearings, which may take up to 70% of the total friction. Our solution is to coat rubbers with flexible diamond-like carbon (DLC) thin film by which the coefficient of friction is reduced from above 1.5 to below 0.15.

  12. Flexible diamond-like carbon thin film coated rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Y.T.

    2015-01-01

    Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 75% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin film, by which the coefficient of friction is reduced to less than one tenth. Coating

  13. Preparation of Nanocrystalline Titania Thin Films by Using Pure and Water-modified Supercritical Carbon Dioxide.

    Czech Academy of Sciences Publication Activity Database

    Sajfrtová, Marie; Cerhová, Marie; Dřínek, Vladislav; Daniš, S.; Matějová, L.

    2016-01-01

    Roč. 117, NOV 2016 (2016), s. 289-296 ISSN 0896-8446 R&D Projects: GA ČR GA14-23274S Institutional support: RVO:67985858 Keywords : titania thin films * supercritical carbon dioxide * crystallization Subject RIV: CA - Inorganic Chemistry Impact factor: 2.991, year: 2016

  14. Graphene crystal growth by thermal precipitation of focused ion beam induced deposition of carbon precursor via patterned-iron thin layers

    Directory of Open Access Journals (Sweden)

    Rius Gemma

    2014-01-01

    Full Text Available Recently, relevant advances on graphene as a building block of integrated circuits (ICs have been demonstrated. Graphene growth and device fabrication related processing has been steadily and intensively powered due to commercial interest; however, there are many challenges associated with the incorporation of graphene into commercial applications which includes challenges associated with the synthesis of this material. Specifically, the controlled deposition of single layer large single crystal graphene on arbitrary supports, is particularly challenging. Previously, we have reported the first demonstration of the transformation of focused ion beam induced deposition of carbon (FIBID-C into patterned graphitic layers by metal-assisted thermal treatment (Ni foils. In this present work, we continue exploiting the FIBID-C approach as a route for graphene deposition. Here, thin patterned Fe layers are used for the catalysis of graphenization and graphitization. We demonstrate the formation of high quality single and few layer graphene, which evidences, the possibility of using Fe as a catalyst for graphene deposition. The mechanism is understood as the minute precipitation of atomic carbon after supersaturation of some iron carbides formed under a high temperature treatment. As a consequence of the complete wetting of FIBID-C and patterned Fe layers, which enable graphene growth, the as-deposited patterns do not preserve their original shape after the thermal treatment

  15. Detection of wall thinning of carbon steel pipe covered with insulation using Pulsed Eddy Current technique

    International Nuclear Information System (INIS)

    Park, Duckgun; Kishore, M. B.; Lee, D. H.

    2013-01-01

    The test sample is a ferromagnetic carbon steel pipe having different thickness, covered with a 10 cm plastic insulation laminated by 0.4 mm Al plate to simulate the pipelines in NPPs. The PEC Probe used for the wall thinning detection consists of an excitation coil and a Hall sensor. The excitation coils in the probe is driven by a rectangular bipolar current pulse and the Hall-sensor will detects the resultant field. The Hall sensor output is considered as PEC signal. Results shows that the PEC system can detect wall thinning in an insulated pipeline of the NPPs. Local wall thinning in pipelines affects the structural integrity of industries like nuclear power plants (NPPs). In the present study a pulsed eddy current (PEC) technology to detect the wall thing of carbon steel pipe covered with insulation is developed

  16. Humidity Sensor Based on Multi-Walled Carbon Nanotube Thin Films

    International Nuclear Information System (INIS)

    Cao, C.L.; Hu, C.G.; Fang, L.; Wang, S.X.; Cao, C.L.; Tian, Y.S.; Pan, C.Y.

    2009-01-01

    The properties of the humidity sensors made of chemically treated and untreated multi-walled carbon nano tube (MWCNT) thin films are investigated systematically. It shows that both the chemically treated and untreated MWCNT thin films demonstrate humidity sensitive properties, but the former have stronger sensitivity than the latter. In the range of 11%-98% relative humidity (RH), the resistances of the chemically treated and untreated MWCNT humidity sensors increase 120% and 28%, respectively. Moreover, the treated humidity sensors showed higher sensitivity and better stability. In addition, the response and recover properties, and stabilization of the humidity sensors are measured, and the humidity sensitive mechanisms of the sensors are analyzed. The humidity sensitivity of carbon nano tube thin films indicates it promise as a kind of humidity sensitive material

  17. Lattice expansion of carbon-stabilized expanded austenite

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The lattice parameter of expanded austenite was determined as a function of the content of interstitially dissolved carbon in homogeneous, carburized thin stainless steel foils. For the first time this expansion of the face-centered cubic lattice is determined on unstrained austenite. It is found...

  18. Aligned carbon nanotube, graphene and graphite oxide thin films via substrate-directed rapid interfacial deposition

    Science.gov (United States)

    D'Arcy, Julio M.; Tran, Henry D.; Stieg, Adam Z.; Gimzewski, James K.; Kaner, Richard B.

    2012-05-01

    A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated.A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated. Electronic supplementary information (ESI) available: Droplet coalescence, catenoid formation, mechanism of film growth, scanning electron micrographs showing carbon nanotube alignment, flexible transparent films of SWCNTs, AFM images of a chemically converted graphene film, and SEM images of SWCNT free-standing thin films. See DOI: 10.1039/c2nr00010e

  19. Platinum containing amorphous hydrogenated carbon (a-C:H/Pt) thin films as selective solar absorbers

    International Nuclear Information System (INIS)

    Lan, Yung-Hsiang; Brahma, Sanjaya; Tzeng, Y.H.; Ting, Jyh-Ming

    2014-01-01

    We have investigated a double-cermet structured thin film in which an a-C:H thin film was used as an anti-reflective (AR) layer and two platinum-containing amorphous hydrogenated carbon (a-C:H/Pt) thin films were used as the double cermet layers. A reactive co-sputter deposition method was used to prepare both the anti-reflective and cermet layers. Effects of the target power and heat treatment were studied. The obtained films were characterized using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy. The optical absorptance and emittance of the as deposited and annealed films were determined using UV–vis-NIR spectroscopy. We show that the optical absorptance of the resulting double-cermet structured thin film is as high as 96% and remains to be 91% after heat treatment at 400 °C, indicating the thermal stability of the film

  20. Multiplicity of secondary electrons emitted by carbon thin targets by impact of H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles at MeV energies; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l`impact de projectiles H{sup 0}, H{sub 2}{sup +} et H{sub 3}{sup +} d`energie de l`ordre du MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vidovic, Zvonimir [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

    1997-06-24

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25 - 2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. Phenomenological and theoretical descriptions as well as a summary of the main theoretical models are the subjects of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of the thin carbon foils crossed by an energetic projectile is described in the chapter two. In this chapter there are also presented the method and the algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H{sup 0} atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of the ions with solids. The role of the proximity of the protons, molecular ions fragments, upon the amplitude of these collected effects is evidenced from the study of the statistics of forward emission. The experiments allowed us to shed light on various aspects of atom and polyatomic ion interactions with solid surfaces. (author) 136 refs., 41 figs., 3 tabs.

  1. Screen-printed carbon electrode modified on its surface with amorphous carbon nitride thin film: Electrochemical and morphological study

    Energy Technology Data Exchange (ETDEWEB)

    Ghamouss, F. [Universite de Nantes, UMR 6006-CNRS, FR-2465-CNRS, Laboratoire d' Analyse isotopique et Electrochimique de Metabolismes (LAIEM) (France); Tessier, P.-Y. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Djouadi, A. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Besland, M.-P. [Universite de Nantes, UMR CNRS 6502, Institut des Materiaux Jean Rouxel - IMN Faculte des Sciences and des Techniques de Nantes, 2 rue de la Houssiniere, 44322 Nantes Cedex 3 (France); Boujtita, M. [Universite de Nantes, UMR 6006-CNRS, FR-2465-CNRS, Laboratoire d' Analyse isotopique et Electrochimique de Metabolismes (LAIEM) (France)]. E-mail: mohammed.boujtita@univ-nantes.fr

    2007-04-20

    The surface of a screen-printed carbon electrode (SPCE) was modified by using amorphous carbon nitride (a-CN {sub x}) thin film deposited by reactive magnetron sputtering. Scanning electron microscopy and photoelectron spectroscopy measurements were used to characterise respectively the morphology and the chemical structure of the a-CN {sub x} modified electrodes. The incorporation of nitrogen in the amorphous carbon network was demonstrated by X ray photoelectron spectroscopy. The a-CN {sub x} layers were deposited on both carbon screen-printed electrode (SPCE) and silicon (Si) substrates. A comparative study showed that the nature of substrate, i.e. SPCE and Si, has a significant effect on both the surface morphology of deposited a-CN {sub x} film and their electrochemical properties. The improvement of the electrochemical reactivity of SPCE after a-CN {sub x} film deposition was highlighted both by comparing the shapes of voltammograms and calculating the apparent heterogeneous electron transfer rate constant.

  2. Deposit of thin films of nitrided amorphous carbon using the laser ablation technique

    International Nuclear Information System (INIS)

    Rebollo, P.B.; Escobar A, L.; Camps C, E.; Haro P, E.; Camacho L, M.A.; Muhl S, S.

    2000-01-01

    It is reported the synthesis and characterization of thin films of amorphous carbon (a-C) nitrided, deposited by laser ablation in a nitrogen atmosphere at pressures which are from 4.5 x 10 -4 Torr until 7.5 x 10 -2 Torr. The structural properties of the films are studied by Raman spectroscopy obtaining similar spectra at the reported for carbon films type diamond. The study of behavior of the energy gap and the ratio nitrogen/carbon (N/C) in the films, shows that the energy gap is reduced when the nitrogen incorporation is increased. It is showed that the refraction index of the thin films diminish as nitrogen pressure is increased, indicating the formation of graphitic material. (Author)

  3. Implementation of Carbon Thin Film Coatings in the Super Proton Synchrotron (SPS) for Electron Cloud Mitigation

    CERN Document Server

    Costa Pinto, P; Basso, T; Edwards, P; Mensi, M; Sublet, A; Taborelli, M

    2014-01-01

    Low Secondary Electron Yield (SEY) carbon thin films eradicate electron multipacting in accelerator beam pipes. Two magnetic cells of the SPS were coated with such material and installed. In total more than forty vacuum vessels and magnet interconnections were treated. The feasibility of the coating process was validated. The performance of the carbon thin film will be tested with LHC nominal beams after the end of the long shutdown 1. Particular attention will be drawn to the long term behaviour. This paper presents the sputtering techniques used to coat the different components; their characterization (SEY measurements on coupons, RF multipacting tests and pump down curves); and the technology to etch the carbon film in case of a faulty coating. The strategy to coat the entire SPS will also be described.

  4. Selective Etching of Thin Single-Walled Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Kavan, Ladislav; Dunsch, L.

    2009-01-01

    Roč. 131, č. 12 (2009), s. 4529-4534 ISSN 0002-7863 R&D Projects: GA AV ČR IAA400400804; GA ČR GC203/07/J067; GA AV ČR IAA400400911 Institutional research plan: CEZ:AV0Z40400503 Keywords : carbon nanotubes * Raman spectroelectrochemistry * Raman spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 8.580, year: 2009

  5. Experimental thin-target and thick-target yields for natOs(α, xn)Pt, natOs(α, X)Os, Ir and natMo(p, xn)Tc nuclear reactions from threshold up to 38 and 45 MeV, by combined single and stacked foil techniques

    International Nuclear Information System (INIS)

    Birattari, Claudio; Bonardi, Mauro; Gini, Luigi; Groppi, Flavia; Menapace, Enzo

    2002-01-01

    The experimental values of thin-target excitation functions for the nuclear reactions: nat Os(α, X) 188,189,191 Pt, 192g,194m Ir in the energy range 11 - 38 MeV and nat Mo(p, xn) 94g,95g,95m,96(m+g) Tc in the energy range 5 - 44 MeV are presented. The experimental values were obtained by cyclotron activation followed by off-line HPGe γ-spectrometry and corrected at the End Of an Instantaneous Bombardment, EOIB. In different cases use was made of single foil and stacked foil techniques, which present significantly different advantages and disadvantages. The thin-target yield values can be easily either numerically or analytically integrated, as a function of both incoming particle energy and energy loss in target itself, in order to calculate apriori the thick-target yield of various radionuclides under any different experimental condition. Moreover, the thin-target yields are directly related to the effective cross-sections of various nuclear reaction channels involved. The data are of relevant interest for optimizing cyclotron production of platinum and technetium radionuclides to be used as radiotracers for metallo-biochemical, biomedical, toxicological and environmental studies. (author)

  6. Preparation of thin nuclear targets

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1979-03-01

    Thin film backings, sources and targets are needed for many applications in low energy nuclear physics and nuclear chemistry experiments. A survey of techniques used in the preparation of nuclear targets is first briefly discussed. These are classified as chemical, mechanical and physical preparations. Vacuum evaporation, being the most generally used technique, is discussed in detail. It is highly desirable to monitor the film thickness and control the deposition rate during evaporation and to measure the final target thickness after deposition has concluded. The relative merits of various thickness measuring techniques are described. Stages in the fabrication and mounting of self-supporting foils are described in detail, with emphasis given to the preparation of thin self-supporting carbon foils used as target backings and stripper foils. Various target backings, and the merits of the more generally used release agents are described in detail. The preparations of more difficult elemental targets are discussed, and a comprehensive list of the common targets is presented

  7. Silicon solar cell performance deposited by diamond like carbon thin film ;Atomic oxygen effects;

    Science.gov (United States)

    Aghaei, Abbas Ail; Eshaghi, Akbar; Karami, Esmaeil

    2017-09-01

    In this research, a diamond-like carbon thin film was deposited on p-type polycrystalline silicon solar cell via plasma-enhanced chemical vapor deposition method by using methane and hydrogen gases. The effect of atomic oxygen on the functioning of silicon coated DLC thin film and silicon was investigated. Raman spectroscopy, field emission scanning electron microscopy, atomic force microscopy and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the structure and morphology of the DLC thin film. Photocurrent-voltage characteristics of the silicon solar cell were carried out using a solar simulator. The results showed that atomic oxygen exposure induced the including oxidation, structural changes, cross-linking reactions and bond breaking of the DLC film; thus reducing the optical properties. The photocurrent-voltage characteristics showed that although the properties of the fabricated thin film were decreased after being exposed to destructive rays, when compared with solar cell without any coating, it could protect it in atomic oxygen condition enhancing solar cell efficiency up to 12%. Thus, it can be said that diamond-like carbon thin layer protect the solar cell against atomic oxygen exposure.

  8. Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation

    International Nuclear Information System (INIS)

    Rebollo P, B.

    2001-01-01

    The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp 2 and sp 3 bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

  9. Piezoresistivity of mechanically drawn single-walled carbon nanotube (SWCNT) thin films-: mechanism and optimizing principle

    Science.gov (United States)

    Obitayo, Waris

    The individual carbon nanotube (CNT) based strain sensors have been found to have excellent piezoresistive properties with a reported gauge factor (GF) of up to 3000. This GF on the other hand, has been shown to be structurally dependent on the nanotubes. In contrast, to individual CNT based strain sensors, the ensemble CNT based strain sensors have very low GFs e.g. for a single walled carbon nanotube (SWCNT) thin film strain sensor, GF is ~1. As a result, studies which are mostly numerical/analytical have revealed the dependence of piezoresistivity on key parameters like concentration, orientation, length and diameter, aspect ratio, energy barrier height and Poisson ratio of polymer matrix. The fundamental understanding of the piezoresistive mechanism in an ensemble CNT based strain sensor still remains unclear, largely due to discrepancies in the outcomes of these numerical studies. Besides, there have been little or no experimental confirmation of these studies. The goal of my PhD is to study the mechanism and the optimizing principle of a SWCNT thin film strain sensor and provide experimental validation of the numerical/analytical investigations. The dependence of the piezoresistivity on key parameters like orientation, network density, bundle diameter (effective tunneling area), and length is studied, and how one can effectively optimize the piezoresistive behavior of a SWCNT thin film strain sensors. To reach this goal, my first research accomplishment involves the study of orientation of SWCNTs and its effect on the piezoresistivity of mechanically drawn SWCNT thin film based piezoresistive sensors. Using polarized Raman spectroscopy analysis and coupled electrical-mechanical test, a quantitative relationship between the strain sensitivity and SWCNT alignment order parameter was established. As compared to randomly oriented SWCNT thin films, the one with draw ratio of 3.2 exhibited ~6x increase on the GF. My second accomplishment involves studying the

  10. Conduction properties of thin films from a water soluble carbon nanotube/hemicellulose complex

    Science.gov (United States)

    Shao, Dongkai; Yotprayoonsak, Peerapong; Saunajoki, Ville; Ahlskog, Markus; Virtanen, Jorma; Kangas, Veijo; Volodin, Alexander; Van Haesendonck, Chris; Burdanova, Maria; Mosley, Connor D. W.; Lloyd-Hughes, James

    2018-04-01

    We have examined the conductive properties of carbon nanotube based thin films, which were prepared via dispersion in water by non-covalent functionalization of the nanotubes with xylan, a type of hemicellulose. Measurements of low temperature conductivity, Kelvin probe force microscopy, and high frequency (THz) conductivity elucidated the intra-tube and inter-tube charge transport processes in this material. The measurements show excellent conductive properties of the as prepared thin films, with bulk conductivity up to 2000 S cm-1. The transport results demonstrate that the hemicellulose does not seriously interfere with the inter-tube conductance.

  11. Fabrication of periodical surface structures by picosecond laser irradiation of carbon thin films: transformation of amorphous carbon in nanographite

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, C.; Dorcioman, G. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125 (Romania); Bita, B. [National Institute for Research and Development in Microtechnologies, 126A Erou Iancu Nicolae Street, Voluntari RO-077190 (Romania); Faculty of Physics, 405 Atomistilor Street, Magurele RO-077125 (Romania); Besleaga, C.; Zgura, I. [National Institute of Materials Physics, 105bis Atomistilor Street, Magurele RO-077125 (Romania); Himcinschi, C. [Institute of Theoretical Physics, TU Bergakademie Freiberg, Freiberg D-09596 (Germany); Popescu, A.C., E-mail: andrei.popescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125 (Romania)

    2016-12-30

    Highlights: • Ripples obtained on carbon films after irradiation with visible ps laser pulses. • Amorphous carbon was transformed in nanographite following irradiation. • Ripples had a complex morphology, being made of islands of smaller ripples. • Hydrophilic carbon films became hydrophobic after surface structuring. - Abstract: Thin films of carbon were synthesized by ns pulsed laser deposition in vacuum on silicon substrates, starting from graphite targets. Further on, the films were irradiated with a picosecond laser source emitting in visible at 532 nm. After tuning of laser parameters, we obtained a film surface covered by laser induced periodical surface structures (LIPSS). They were investigated by optical, scanning electron and atomic force microscopy. It was observed that changing the irradiation angle influences the LIPSS covered area. At high magnification it was revealed that the LIPSS pattern was quite complex, being composed of other small LIPSS islands, interconnected by bridges of nanoparticles. Raman spectra for the non-irradiated carbon films were typical for a-C type of diamond-like carbon, while the LIPSS spectra were characteristic to nano-graphite. The pristine carbon film was hydrophilic, while the LIPSS covered film surface was hydrophobic.

  12. Percolation effects in supercapacitors with thin, transparent carbon nanotube electrodes.

    Science.gov (United States)

    King, Paul J; Higgins, Thomas M; De, Sukanta; Nicoloso, Norbert; Coleman, Jonathan N

    2012-02-28

    We have explored the effects of percolation on the properties of supercapacitors with thin nanotube networks as electrodes. We find the equivalent series resistance, R(ESR), and volumetric capacitance, C(V), to be thickness independent for relatively thick electrodes. However, once the electrode thickness falls below a threshold thickness (∼100 nm for R(ESR) and ∼20 nm for C(V)), the properties of the electrode become thickness dependent. We show the thickness dependence of both R(ESR) and C(V) to be consistent with percolation theory. While this is expected for R(ESR), that the capacitance follows a percolation scaling law is not. This occurs because, for sparse networks, the capacitance is proportional to the fraction of nanotubes connected to the main network. This fraction, in turn, follows a percolation scaling law. This allows us to understand and quantify the limitations on the achievable capacitance for transparent supercapacitors. We find that supercapacitors with thickness independent R(ESR) and C(V) occupy a well-defined region of the Ragone plot. However, supercapacitors whose electrodes are limited by percolation occupy a long tail to lower values of energy and power density. For example, replacing electrodes with transparency of T = 80% with thinner networks displaying T = 97% will result in a 20-fold reduction of both power and energy density.

  13. ZnO thin films on single carbon fibres fabricated by Pulsed Laser Deposition (PLD)

    Energy Technology Data Exchange (ETDEWEB)

    Krämer, André; Engel, Sebastian [Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, 07743 Jena (Germany); Sangiorgi, Nicola [Institute of Science and Technology for Ceramics – National Research Council of Italy (CNR-ISTEC), via Granarolo 64, 48018 Faenza, RA (Italy); Department of Chemical Science and Technologies, University of Rome Tor Vergata, via della Ricerca Scientifica, 00133 Rome (Italy); Sanson, Alessandra [Institute of Science and Technology for Ceramics – National Research Council of Italy (CNR-ISTEC), via Granarolo 64, 48018 Faenza, RA (Italy); Bartolomé, Jose F. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), C/Sor Juana Inés de la Cruz 3, 28049 Madrid (Spain); Gräf, Stephan, E-mail: stephan.graef@uni-jena.de [Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, 07743 Jena (Germany); Müller, Frank A. [Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, 07743 Jena (Germany); Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena (Germany)

    2017-03-31

    Highlights: • Carbon fibres were entirely coated with thin films consisting of aligned ZnO crystals. • A Q-switched CO2 laser was utilised as radiation source. • Suitability of ZnO thin films on carbon fibres as photo anodes for DSSC was studied. - Abstract: Single carbon fibres were 360° coated with zinc oxide (ZnO) thin films by pulsed laser deposition using a Q-switched CO{sub 2} laser with a pulse duration τ ≈ 300 ns, a wavelength λ = 10.59 μm, a repetition frequency f{sub rep} = 800 Hz and a peak power P{sub peak} = 15 kW in combination with a 3-step-deposition technique. In a first set of experiments, the deposition process was optimised by investigating the crystallinity of ZnO films on silicon and polished stainless steel substrates. Here, the influence of the substrate temperature and of the oxygen partial pressure of the background gas were characterised by scanning electron microscopy and X-ray diffraction analyses. ZnO coated carbon fibres and conductive glass sheets were used to prepare photo anodes for dye-sensitised solar cells in order to investigate their suitability for energy conversion devices. To obtain a deeper insight of the electronic behaviour at the interface between ZnO and substrate I–V measurements were performed.

  14. Pathways to Mesoporous Resin/Carbon Thin Films with Alternating Gyroid Morphology

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qi [Department; Matsuoka, Fumiaki [Department; Suh, Hyo Seon [Institute; Materials; Beaucage, Peter A. [Department; Xiong, Shisheng [Institute; Materials; Smilgies, Detlef-M. [Cornell; Tan, Kwan Wee [Department; School; Werner, Jörg G. [Department; Nealey, Paul F. [Institute; Materials; Wiesner, Ulrich B. [Department

    2017-12-19

    Three-dimensional (3D) mesoporous thin films with sub-100 nm periodic lattices are of increasing interest as templates for a number of nanotechnology applications, yet are hard to achieve with conventional top-down fabrication methods. Block copolymer self-assembly derived mesoscale structures provide a toolbox for such 3D template formation. In this work, single (alternating) gyroidal and double gyroidal mesoporous thin-film structures are achieved via solvent vapor annealing assisted co-assembly of poly(isoprene-block-styrene-block-ethylene oxide) (PI-b-PS-b-PEO, ISO) and resorcinol/phenol formaldehyde resols. In particular, the alternating gyroid thin-film morphology is highly desirable for potential template backfilling processes as a result of the large pore volume fraction. In situ grazing-incidence small-angle X-ray scattering during solvent annealing is employed as a tool to elucidate and navigate the pathway complexity of the structure formation processes. The resulting network structures are resistant to high temperatures provided an inert atmosphere. The thin films have tunable hydrophilicity from pyrolysis at different temperatures, while pore sizes can be tailored by varying ISO molar mass. A transfer technique between substrates is demonstrated for alternating gyroidal mesoporous thin films, circumventing the need to re-optimize film formation protocols for different substrates. Increased conductivity after pyrolysis at high temperatures demonstrates that these gyroidal mesoporous resin/carbon thin films have potential as functional 3D templates for a number of nanomaterials applications.

  15. Synthesis and characterization of boron incorporated diamond-like carbon thin films

    International Nuclear Information System (INIS)

    Zhang, L.L.; Yang, Q.; Tang, Y.; Yang, L.; Zhang, C.; Hu, Y.; Cui, X.

    2015-01-01

    Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B 4 C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B 4 C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp 3 bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp 3 bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp 3 bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films

  16. Automatic spark counting of alpha-tracks in plastic foils

    International Nuclear Information System (INIS)

    Somogyi, G.; Medveczky, L.; Hunyadi, I.; Nyako, B.

    1976-01-01

    The possibility of alpha-track counting by jumping spark counter in cellulose acetate and polycarbonate nuclear track detectors was studied. A theoretical treatment is presented which predicts the optimum residual thickness of the etched foils in which completely through-etched tracks (i.e. holes) can be obtained for alpha-particles of various energies and angles of incidence. In agreement with the theoretical prediction it is shown that a successful spark counting of alpha-tracks can be performed even in polycarbonate foils. Some counting characteristics, such as counting efficiency vs particle energy at various etched foil thicknesses, surface spark density produced by electric breakdowns in unexposed foils vs foil thickness, etc. have been determined. Special attention was given to the spark counting of alpha-tracks entering thin detectors at right angle. The applicability of the spark counting technique is demonstrated in angular distribution measurements of the 27 Al(p,α 0 ) 24 Mg nuclear reaction at Ep = 1899 keV resonance energy. For this study 15 μm thick Makrofol-G foils and a jumping spark counter of improved construction were used. (orig.) [de

  17. FOIL ELEMENT FOR NUCLEAR REACTOR

    Science.gov (United States)

    Noland, R.A.; Walker, D.E.; Spinrad, B.I.

    1963-07-16

    A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

  18. Development of carbon steel with superior resistance to wall thinning and fracture for nuclear piping system

    International Nuclear Information System (INIS)

    Rhee, Chang Kyu; Lee, Min Ku; Park, Jin Ju

    2010-07-01

    Carbon steel is usually used for piping for secondary coolant system in nuclear power plant because of low cost and good machinability. However, it is generally reported that carbon steel was failed catastrophically because of its low resistance to wall thinning and fracture toughness. Especially, flow accelerated corrosion (FAC) is one of main problems of the wall thinning of piping in the nuclear power plant. Therefore, in this project, fabrication technology of new advanced carbon steel materials modified by dispersion of nano-carbide ceramics into the matrix is developed first in order to improve the resistance to wall thinning and fracture toughness drastically compared to the conventional one. In order to get highly wettable fine TiC ceramic particles into molten metal, the micro-sized TiC particles were first mechanically milled by Fe (MMed TiC/Fe) in a high energy ball mill machine in Ar gas atmosphere, and then mixed with surfactant metal elements (Sn, Cr, Ni) to obtain better wettability, as this lowered surface tension of the carbon steel melt. According to microscopic images revealed that an addition of MMed TiC/Fe-surfactant mixed powders favorably disperses the fine TiC particles in the carbon steel matrix. It was also found that the grain size refinement of the cast matrix is achieved remarkably when fine TiC particles were added due to the fact that they act as nucleation sites during the solidification process. As a results, a cast carbon steel dispersed with fine TiC particles shows improved mechanical properties such as hardness, tensile strength and cavitation resistance compared to that of without particles. However, the slight decrease of toughness was found

  19. Electrodeposition of Uranium and Plutonium on Thin Carbon and Titanium Substrates

    International Nuclear Information System (INIS)

    Henderson, R.A.; Gostic, J.M.; Burke, J.T.; Fisher, S.E.; Wu, C.Y.

    2011-01-01

    Preparation of Pu and U targets on thin natural C (100 (micro)g/cm 2 ) and ti (2 and 3 (micro)m) substrates is described. The Actinide material of interest was first purified using ion exchange chromatography to remove any matrix contaminants or decay products present in the parent stock solution. The actinide solution was prepared in 0.05 M HNO 3 with a final aliquot volume not exceeding 100 (micro)L for the deposition procedure. The electroplating cells were developed in-house and were primarily made of Teflon. The source material deposited ranged from 125 to 400 (micro)g/cm 2 . It was determined that multiple layers of U and Pu were required to produce thicker targets on Ti. Plating efficiency was greatly affected by the cell volume, solution aliquot size, pre-treatment of the foils, solution mixing during palting, and the fit of the electrode contact with the target substrate. The final procedure used for deposition is described in detail.

  20. Room-temperature low-voltage electroluminescence in amorphous carbon nitride thin films

    Science.gov (United States)

    Reyes, R.; Legnani, C.; Ribeiro Pinto, P. M.; Cremona, M.; de Araújo, P. J. G.; Achete, C. A.

    2003-06-01

    White-blue electroluminescent emission with a voltage bias less than 10 V was achieved in rf sputter-deposited amorphous carbon nitride (a-CN) and amorphous silicon carbon nitride (a-SiCN) thin-film-based devices. The heterojunction structures of these devices consist of: Indium tin oxide (ITO), used as a transparent anode; amorphous carbon film as an emission layer, and aluminum as a cathode. The thickness of the carbon films was about 250 Å. In all of the produced diodes, a stable visible emission peaked around 475 nm is observed at room temperature and the emission intensity increases with the current density. For an applied voltage of 14 V, the luminance was about 3 mCd/m2. The electroluminescent properties of the two devices are discussed and compared.

  1. Logic circuits composed of flexible carbon nanotube thin-film transistor and ultra-thin polymer gate dielectric

    Science.gov (United States)

    Lee, Dongil; Yoon, Jinsu; Lee, Juhee; Lee, Byung-Hyun; Seol, Myeong-Lok; Bae, Hagyoul; Jeon, Seung-Bae; Seong, Hyejeong; Im, Sung Gap; Choi, Sung-Jin; Choi, Yang-Kyu

    2016-05-01

    Printing electronics has become increasingly prominent in the field of electronic engineering because this method is highly efficient at producing flexible, low-cost and large-scale thin-film transistors. However, TFTs are typically constructed with rigid insulating layers consisting of oxides and nitrides that are brittle and require high processing temperatures, which can cause a number of problems when used in printed flexible TFTs. In this study, we address these issues and demonstrate a method of producing inkjet-printed TFTs that include an ultra-thin polymeric dielectric layer produced by initiated chemical vapor deposition (iCVD) at room temperature and highly purified 99.9% semiconducting carbon nanotubes. Our integrated approach enables the production of flexible logic circuits consisting of CNT-TFTs on a polyethersulfone (PES) substrate that have a high mobility (up to 9.76 cm2 V-1 sec-1), a low operating voltage (less than 4 V), a high current on/off ratio (3 × 104), and a total device yield of 90%. Thus, it should be emphasized that this study delineates a guideline for the feasibility of producing flexible CNT-TFT logic circuits with high performance based on a low-cost and simple fabrication process.

  2. Deposition techniques for the preparation of thin film nuclear targets

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1987-07-01

    This review commences with a brief description of the basic principles that regulate vacuum evaporation and the physical processes involved in thin film formation, followed by a description of the experimental methods used. The principle methods of heating the evaporant are detailed and the means of measuring and controlling the film thickness are elucidated. Types of thin film nuclear targets are considered and various film release agents are listed. Thin film nuclear target behaviour under ion-bombardment is described and the dependence of nuclear experimental results upon target thickness and uniformity is outlined. Special problems associated with preparing suitable targets for lifetime measurements are discussed. The causes of stripper-foil thickening and breaking under heavy-ion bombardment are considered. A comparison is made between foils manufactured by a glow discharge process and those produced by vacuum sublimation. Consideration is given to the methods of carbon stripper-foil manufacture and to the characteristics of stripper-foil lifetimes are considered. Techniques are described that have been developed for the fabrication of special targets, both from natural and isotopically enriched material, and also of elements that are either chemically unstable, or thermally unstable under irradiation. The reduction of metal oxides by the use of hydrogen or by utilising a metallothermic technique, and the simultaneous evaporation of reduced rare earth elements is described. A comprehensive list of the common targets is presented

  3. Controlling thin film structure for the dewetting of catalyst nanoparticle arrays for subsequent carbon nanofiber growth

    International Nuclear Information System (INIS)

    Randolph, S J; Fowlkes, J D; Melechko, A V; Klein, K L; III, H M Meyer; Simpson, M L; Rack, P D

    2007-01-01

    Vertically aligned carbon nanofiber (CNF) growth is a catalytic chemical vapor deposition process in which structure and functionality is controlled by the plasma conditions and the properties of the catalyst nanoparticles that template the fiber growth. We have found that the resultant catalyst nanoparticle network that forms by the dewetting of a continuous catalyst thin film is dependent on the initial properties of the thin film. Here we report the ability to tailor the crystallographic texture and composition of the nickel catalyst film and subsequently the nanoparticle template by varying the rf magnetron sputter deposition conditions. After sputtering the Ni catalyst thin films, the films are heated and exposed to an ammonia dc plasma, to chemically reduce the native oxide on the films and induce dewetting of the film to form nanoparticles. Subsequent nanoparticle treatment in an acetylene plasma at high substrate temperature results in CNF growth. Evidence is presented that the texture and composition of the nickel thin film has a significant impact on the structure and composition of the formed nanoparticle, as well as the resultant CNF morphology. Nickel films with a preferred (111) or (100) texture were produced and conditions favoring interfacial silicidation reactions were identified and investigated. Both compositional and structural analysis of the films and nanoparticles indicate that the properties of the as-deposited Ni catalyst film influences the subsequent nanoparticle formation and ultimately the catalytic growth of the carbon nanofibers

  4. Semiconducting Properties of Nanostructured Amorphous Carbon Thin Films Incorporated with Iodine by Thermal Chemical Vapor Deposition

    Science.gov (United States)

    Kamaruzaman, Dayana; Ahmad, Nurfadzilah; Annuar, Ishak; Rusop, Mohamad

    2013-11-01

    Nanostructured iodine-post doped amorphous carbon (a-C:I) thin films were prepared from camphor oil using a thermal chemical vapor deposition (TCVD) technique at different doping temperatures. The structural properties of the films were studied by field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Raman, and Fourier transform infrared (FTIR) studies. FESEM and EDS studies showed successful iodine doping. FTIR and Raman studies showed that the a-C:I thin films consisted of a mixture of sp2- and sp3-bonded carbon atoms. The optical and electrical properties of a-C:I thin films were determined by UV-vis-NIR spectroscopy and current-voltage (I-V) measurement respectively. The optical band gap of a-C thin films decreased upon iodine doping. The highest electrical conductivity was found at 400 °C doping. Heterojunctions are confirmed by rectifying the I-V characteristics of an a-C:I/n-Si junction.

  5. Preparation and electrochemical properties of gold nanoparticles containing carbon nanotubes-polyelectrolyte multilayer thin films

    International Nuclear Information System (INIS)

    Yu Aimin; Zhang Xing; Zhang Haili; Han, Deyan; Knight, Allan R.

    2011-01-01

    Highlights: → Gold nanoparticles containing carbon nanotubes-polyelectrolyte multilayer thin films were prepared via layer-by-layer self-assembly technique. → The electron transfer behaviour of the hybrid thin films were investigated using an electrochemical probe. → The resulting thin films exhibited an electrocatalytic activity towards the oxidation of nitric oxide. - Abstract: Multi-walled carbon nanotubes (MWCNT)/polyelectrolyte (PE) hybrid thin films were fabricated by alternatively depositing negatively charged MWCNT and positively charged (diallyldimethylammonium chloride) (PDDA) via layer-by-layer (LbL) assembly technique. The stepwise growth of the multilayer films of MWCNT and PDDA was characterized by UV-vis spectroscopy. Scanning electron microscopy (SEM) images indicated that the MWCNT were uniformly embedded in the film to form a network and the coverage density of MWCNT increased with layer number. Au nanoparticles (NPs) could be further adsorbed onto the film to form PE/MWCNT/Au NPs composite films. The electron transfer behaviour of multilayer films with different compositions were studied by cyclic voltammetry using [Fe(CN) 6 ] 3-/4- as an electrochemical probe. The results indicated that the incorporation of MWCNT and Au NPs not only greatly improved the electronic conductivity of pure polyelectrolyte films, but also provided excellent electrocatalytic activity towards the oxidation of nitric oxide (NO).

  6. Medium scale carbon nanotube thin film integrated circuits on flexible plastic substrates

    Science.gov (United States)

    Rogers, John A; Cao, Qing; Alam, Muhammad; Pimparkar, Ninad

    2015-02-03

    The present invention provides device components geometries and fabrication strategies for enhancing the electronic performance of electronic devices based on thin films of randomly oriented or partially aligned semiconducting nanotubes. In certain aspects, devices and methods of the present invention incorporate a patterned layer of randomly oriented or partially aligned carbon nanotubes, such as one or more interconnected SWNT networks, providing a semiconductor channel exhibiting improved electronic properties relative to conventional nanotubes-based electronic systems.

  7. Influence of thin film nickel pretreatment on catalytic thermal chemical vapor deposition of carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Tiggelaar, R.M. [Mesoscale Chemical Systems, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Thakur, D.B.; Nair, H.; Lefferts, L.; Seshan, K. [Catalytic Processes and Materials, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Gardeniers, J.G.E., E-mail: j.g.e.gardeniers@utwente.nl [Mesoscale Chemical Systems, MESA" + Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2013-05-01

    Nickel and other metal nanoparticles are known to be active as catalysts in the synthesis of carbon nanofibers. In this paper we investigate how dewetting and break-up of nickel thin films depends on film thickness, film–substrate interaction and pretreatment conditions. This is evaluated for films evaporated on oxidized silicon and fused silica substrates with or without tantalum coating, which were subsequently exposed to different pretreatment atmospheres (vacuum, nitrogen, air and hydrogen; 1 h, 650 °C). Atomic force microscopy, scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the films. Pretreated Ni films were subjected to a thermal catalytic chemical vapor deposition procedure with brief ethylene exposures (0.5–3 min, 635 °C). It was found that only on the spherical nanoparticles originating from a hydrogen pretreatment of a Ni film with Ta adhesion layer, homogeneously distributed, randomly-oriented, well-attached, and semi-crystalline carbon nanofibers be synthesized. - Highlights: • On the formation of nanoparticles required for carbon nanofiber (CNF) synthesis • Various evaporated thin films on oxidized silicon and fused silica: Ni and Ni/Ta • Pretreatment of nickel-based thin films in vacuum, nitrogen, air and hydrogen • Only on reduced Ni/Ta fast – within 3 min – initiation of CNF nucleation and growth.

  8. Control of wettability of hydrogenated amorphous carbon thin films by laser-assisted micro- and nanostructuring

    International Nuclear Information System (INIS)

    Pfleging, Wilhelm; Kohler, Robert; Torge, Maika; Trouillet, Vanessa; Danneil, Friederike; Stueber, Michael

    2011-01-01

    A flexible and rapid surface functionalization of amorphous carbon films shows a great potential for various application fields such as biological surfaces and tribological systems. For this purpose, the combination of thin film deposition and subsequent laser material processing was investigated. Amorphous carbon layers doped with hydrogen were deposited on silicon wafers by reactive direct-current magnetron sputtering. Films with three different hydrogen contents were synthesized. Subsequent to the thin film deposition process, UV laser material processing at wavelengths of 193 nm or 248 nm was performed with respect to chemical surface modification and surface structuring on micro- and nanometer scale. Depending on structure size and laser-induced chemical surface modification the adjustment of the surface energy and wetting behaviour in a broad range from hydrophobic to hydrophilic was possible. The chemical modification and the ablation mechanisms near the ablation threshold were strongly influenced by the hydrogen content in amorphous carbon thin films. Structural and chemical information of the as-deposited and modified films was obtained by Raman spectroscopy, X-ray photoelectron spectroscopy and contact angle measurements.

  9. Stable, microfabricated thin layer chromatography plates without volume distortion on patterned, carbon and Al₂O₃-primed carbon nanotube forests.

    Science.gov (United States)

    Jensen, David S; Kanyal, Supriya S; Gupta, Vipul; Vail, Michael A; Dadson, Andrew E; Engelhard, Mark; Vanfleet, Richard; Davis, Robert C; Linford, Matthew R

    2012-09-28

    Some of us recently described the fabrication of thin layer chromatography (TLC) plates from patterned carbon nanotube (CNT) forests via direct infiltration/coating of the CNTs by low pressure chemical vapor deposition (LPCVD) of silicon from SiH₄, followed by high temperature oxidation of the CNTs and Si. Herein we present an improved microfabrication process for the preparation of these TLC plates. First, a few nanometers of carbon and/or a thin film of Al₂O₃ is deposited on the CNTs. This method of priming the CNTs for subsequent depositions appears to be new. X-ray photoelectron spectroscopy confirms the presence of additional oxygen after carbon deposition. After priming, the plates are coated by rapid, conformal deposition of an inorganic material that does not require subsequent oxidation, i.e., by a fast pseudo atomic layer deposition (ψ-ALD) of SiO₂ from trimethylaluminum and tris(tert-butoxy)silanol. Unlike devices described previously, faithful reproduction of the features in the masks is still observed after oxidation. A bonded, amino phase on the resulting plates shows fast, highly efficient separations of fluorescent dyes (plate heights in the range of 1.6-7.7 μm). Extensive characterization of the new materials by TEM, SEM, EDAX, DRIFT, and XPS is reported. A substantially lower process temperature for the removal of the CNT scaffold is possible as a result of the already oxidized materials used. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Nanotribological Behavior of Carbon Based Thin Films: Friction and Lubricity Mechanisms at the Nanoscale

    Directory of Open Access Journals (Sweden)

    Costas A. Charitidis

    2013-04-01

    Full Text Available The use of materials with very attractive friction and wear properties has raised much attention in research and industrial sectors. A wide range of tribological applications, including rolling and sliding bearings, machining, mechanical seals, biomedical implants and microelectromechanical systems (MEMS, require thin films with high mechanical strength, chemical inertness, broad optical transparency, high refractive index, wide bandgap excellent thermal conductivity and extremely low thermal expansion. Carbon based thin films like diamond, diamond-like carbon, carbon nitride and cubic boron nitride known as “super-hard” material have been studied thoroughly as the ideal candidate for tribological applications. In this study, the results of experimental and simulation works on the nanotribological behavior of carbon films and fundamental mechanisms of friction and lubricity at the nano-scale are reviewed. The study is focused on the nanomechanical properties and analysis of the nanoscratching processes at low loads to obtain quantitative analysis, the comparison obtain quantitative analysis, the comparison of their elastic/plastic deformation response, and nanotribological behavior of the a-C, ta-C, a-C:H, CNx, and a-C:M films. For ta-C and a-C:M films new data are presented and discussed.

  11. Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

    Science.gov (United States)

    Iskandar, F.; Aimon, A. H.; Akmaluddin, A. R.; Nuryadin, B. W.; Abdullah, M.

    2016-08-01

    Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices.

  12. Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

    International Nuclear Information System (INIS)

    Iskandar, F; Aimon, A H; Akmaluddin, A R; Abdullah, M; Nuryadin, B W

    2016-01-01

    Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices. (paper)

  13. Coating of carbon short fibers with thin ceramic layers by chemical vapor deposition

    International Nuclear Information System (INIS)

    Hackl, Gerrit; Gerhard, Helmut; Popovska, Nadejda

    2006-01-01

    Carbon short fiber bundles with a length of 6 mm were uniformly coated using specially designed, continuous chemical vapor deposition (CVD) equipment. Thin layers of titanium nitride, silicon nitride (SiC) and pyrolytic carbon (pyC) were deposited onto several kilograms of short fibers in this large scale CVD reactor. Thermo-gravimetric analyses and scanning electron microscopy investigations revealed layer thicknesses between 20 and 100 nm on the fibers. Raman spectra of pyC coated fibers show a change of structural order depending on the CVD process parameters. For the fibers coated with SiC, Raman investigations showed a deposition of amorphous SiC. The coated carbon short fibers will be applied as reinforcing material in composites with ceramic and metallic matrices

  14. Large carbon cluster thin film gauges for measuring aerodynamic heat transfer rates in hypersonic shock tunnels

    International Nuclear Information System (INIS)

    Srinath, S; Reddy, K P J

    2015-01-01

    Different types of Large Carbon Cluster (LCC) layers are synthesized by a single-step pyrolysis technique at various ratios of precursor mixture. The aim is to develop a fast responsive and stable thermal gauge based on a LCC layer which has relatively good electrical conduction in order to use it in the hypersonic flow field. The thermoelectric property of the LCC layer has been studied. It is found that these carbon clusters are sensitive to temperature changes. Therefore suitable thermal gauges were developed for blunt cone bodies and were tested in hypersonic shock tunnels at a flow Mach number of 6.8 to measure aerodynamic heating. The LCC layer of this thermal gauge encounters high shear forces and a hostile environment for test duration in the range of a millisecond. The results are favorable to use large carbon clusters as a better sensor than a conventional platinum thin film gauge in view of fast responsiveness and stability. (paper)

  15. Acceleration of polyethelene foils by laser driven ablation

    International Nuclear Information System (INIS)

    Ahlstrom, H.G.; Burginyon, G.A.; Haas, R.A.

    1974-01-01

    The production of thermonuclear energy, by laser driven implosion of spherical DT shells, with achievable laser technology, requires the development of an efficient and stable implosion. Certain aspects of the acceleration of the spherical shells can be studied experimentally by irradiating thin, 5 to 25 μm, polyethelene foils. The results of foil acceleration experiments performed using a Nd:YAG-Glass laser capable of producing 150 J, 1 nsec pulses will be discussed. The dynamics of the accelerated foil, the ion blow off, high energy electron spectrum (6 to 180 keV), x-ray spectrum (1 to 150 keV) the spatial distribution of the x-ray emission, the laser beam focal spot energy distribution, the laser temporal pulse shape and spectrum for reflected and transmitted radiation have all been measured simultaneously. The results of these measurements are compared with detailed numerical simulations. (U.S.)

  16. Highly sensitive urea sensing with ion-irradiated polymer foils

    International Nuclear Information System (INIS)

    Fink, Dietmar; Muñoz Hernandez, Gerardo; Alfonta, Lital

    2012-01-01

    Recently we prepared urea-sensors by attaching urease to the inner walls of etched ion tracks within thin polymer foil. Here, alternative track-based sensor configurations are examined where the enzyme remained in solution. The conductivities of systems consisting of two parallel irradiated polymer foils and confining different urea/urease mixtures in between were examined. The correlations between conductivity and urea concentration differed strongly for foils with unetched and etched tracks, which points at different sensing mechanisms – tentatively attributed to the adsorption of enzymatic reaction products on the latent track entrances and to the enhanced conductivity of reaction product-filled etched tracks, respectively. All examined systems enable in principle, urea sensing. They point at the possibility of sensor cascade construction for more sensitive or selective sensor systems.

  17. Molecular enhancement of Balmer emissions following foil-induced dissociation of fast H2+ and H3+ ions

    International Nuclear Information System (INIS)

    Kobayashi, H.; Oda, N.

    1984-01-01

    Relative emission yields of Balmer lines as functions of the dwell time (t/sub D/ = 0.97--54.1 fs) in thin carbon foils (2--68 μg/cm 2 ) have been measured with (0.2--0.8)-MeV/amu H + , H 2 + , and H 3 + incident on thin carbon foils. Large molecular effects for emission yields of Balmer lines have been observed for H 2 + and H 3 + , where the molecular effect for H 3 + is larger than that for H 2 + . The molecular effects for H 2 + and H 3 + depend on the principal quantum number (n = 3--6), but this n dependence disappears at the largest t/sub D/ ( = 54.1 fs). The molecular effects rapidly decrease with increasing t/sub D/ in the small-t/sub D/ ( or approx. =2 fs) region. The magnitudes of the molecular effects at the largest t/sub D/ ( = 54.1 fs) are in good agreement with those by Andresen et al. [Phys. Scr. 19, 335 (1979)]. Relative populations of n-state hydrogens in the large-t/sub D/ (> or approx. =2 fs) region have been derived from the relative yields of Balmer lines as functions of n and t/sub D/. The molecular enhancement for relative populations of n-state hydrogens for H 2 + depends on n and t/sub D/, and decreases with increasing t/sub D/ and increases with increasing n

  18. A display module implemented by the fast high-temperatue response of carbon nanotube thin yarns.

    Science.gov (United States)

    Wei, Yang; Liu, Peng; Jiang, Kaili; Fan, Shoushan

    2012-05-09

    Suspending superaligned multiwalled carbon nanotube (MWCNT) films were processed into CNT thin yarns, about 1 μm in diameter, by laser cutting and an ethanol atomization bath treatment. The fast high-temperature response under a vacuum was revealed by monitoring the incandescent light with a photo diode. The thin yarns can be electrically heated up to 2170 K in 0.79 mS, and the succeeding cool-down time is 0.36 mS. The fast response is attributed to the ultrasmall mass of the independent single yarn, large radiation coefficient, and improved thermal conductance through the two cool ends. The millisecond response time makes it possible to use the visible hot thin yarns as light-emitting elements of an incandescent display. A fully sealed display with 16 × 16 matrix was successfully fabricated using screen-printed thick electrodes and CNT thin yarns. It can display rolling characters with a low power consumption. More applications can be further developed based on the addressable CNT thermal arrays.

  19. Combined sonochemical/CVD method for preparation of nanostructured carbon-doped TiO{sub 2} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Rasoulnezhad, Hossein [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Kavei, Ghassem, E-mail: kaveighassem@gmail.com [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Ahmadi, Kamran [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Rahimipour, Mohammad Reza [Ceramic Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of)

    2017-06-30

    Highlights: • Combination of sonochemical and CVD methods for preparation of nanostructured carbon-doped TiO{sub 2} thin film on glass substrate, for the first time. • High transparency, monodispersity and homogeneity of the prepared thin films. • Preparation of the carbon-doped TiO{sub 2} thin films with nanorod and nanosphere morphologies. - Abstract: The present work reports the successful synthesis of the nanostructured carbon-doped TiO{sub 2} thin films on glass substrate by combination of chemical vapor deposition (CVD) and ultrasonic methods, for the first time. In this method the ultrasound waves act as nebulizer for converting of sonochemically prepared TiO{sub 2} sol to the mist particles. These mist particles were thermally decomposed in subsequent CVD chamber at 320 °C to produce the carbon-doped TiO{sub 2} thin films. The obtained thin films were characterized by means of X-ray Diffraction (XRD), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques. The results show that the prepared thin films have anatase crystal structure and nanorod morphology, which calcination of them at 800 °C results in the conversion of nanorods to nanoparticles. In addition, the prepared samples have high transparency, monodispersity and homogeneity. The presence of the carbon element in the structure of the thin films causes the narrowing of the band-gap energy of TiO{sub 2} to about 2.8 eV, which results in the improvement of visible light absorption capabilities of the thin film.

  20. Neutral hydrogen from the foil-induced dissociation of 4HeH+, 3HeH+, and H2+

    International Nuclear Information System (INIS)

    Cooney, P.J.; Gemmell, D.S.; Kanter, E.P.; Pietsch, W.J.; Zabransky, B.J.

    1979-01-01

    High resolution energy spectra and angular distributions of H 0 from the dissociation of 4 HeH + , 3 HeH + , and H 2 + in thin carbon foils are presented for incident ion energies ranging from 170 to 1800 keV/amu. For the range of dwell times inside the target foils studied (about 1 to 10 fsec), the dominant mechanism for such dissociation is the Coulomb explosion of the ions inside the target followed by electron capture near the rear surface of the foil. At the shortest of these dwell times, the yield of H 0 for incident ions oriented perpendicular to the beam relative to that for ions aligned with the beam is a factor of two greater than at longer dwell times. These data indicate that, for ion fragments which emerge from the rear surface of the target within a few angstroms of one another, those in the perpendicular orientation have a greater electron capture probability than those emerging in other orientations. 9 references

  1. Titanyl phthalocyanine ambipolar thin film transistors making use of carbon nanotube electrodes

    Science.gov (United States)

    Coppedè, Nicola; Valitova, Irina; Mahvash, Farzaneh; Tarabella, Giuseppe; Ranzieri, Paolo; Iannotta, Salvatore; Santato, Clara; Martel, Richard; Cicoira, Fabio

    2014-12-01

    The capability of efficiently injecting charge carriers into organic films and finely tuning their morphology and structure is crucial to improve the performance of organic thin film transistors (OTFTs). In this work, we investigate OTFTs employing carbon nanotubes (CNTs) as the source-drain electrodes and, as the organic semiconductor, thin films of titanyl phthalocyanine (TiOPc) grown by supersonic molecular beam deposition (SuMBD). While CNT electrodes have shown an unprecedented ability to improve charge injection in OTFTs, SuMBD is an effective technique to tune film morphology and structure. Varying the substrate temperature during deposition, we were able to grow both amorphous (low substrate temperature) and polycrystalline (high substrate temperature) films of TiOPc. Regardless of the film morphology and structure, CNT electrodes led to superior charge injection and transport performance with respect to benchmark Au electrodes. Vacuum annealing of polycrystalline TiOPc films with CNT electrodes yielded ambipolar OTFTs.

  2. Titanyl phthalocyanine ambipolar thin film transistors making use of carbon nanotube electrodes

    International Nuclear Information System (INIS)

    Coppedè, Nicola; Tarabella, Giuseppe; Ranzieri, Paolo; Iannotta, Salvatore; Valitova, Irina; Cicoira, Fabio; Mahvash, Farzaneh; Santato, Clara; Martel, Richard

    2014-01-01

    The capability of efficiently injecting charge carriers into organic films and finely tuning their morphology and structure is crucial to improve the performance of organic thin film transistors (OTFTs). In this work, we investigate OTFTs employing carbon nanotubes (CNTs) as the source-drain electrodes and, as the organic semiconductor, thin films of titanyl phthalocyanine (TiOPc) grown by supersonic molecular beam deposition (SuMBD). While CNT electrodes have shown an unprecedented ability to improve charge injection in OTFTs, SuMBD is an effective technique to tune film morphology and structure. Varying the substrate temperature during deposition, we were able to grow both amorphous (low substrate temperature) and polycrystalline (high substrate temperature) films of TiOPc. Regardless of the film morphology and structure, CNT electrodes led to superior charge injection and transport performance with respect to benchmark Au electrodes. Vacuum annealing of polycrystalline TiOPc films with CNT electrodes yielded ambipolar OTFTs. (paper)

  3. Thin-Sheet zinc-coated and carbon steels laser welding

    International Nuclear Information System (INIS)

    Pecas, P.; Gouveia, H.; Quintino, L.

    1998-01-01

    This paper describes the results of a research on CO 2 laser welding of thin-sheet carbon steels (Zinc-coated and uncoated), at several thicknesses combinations. Laser welding has an high potential to be applied on sub-assemblies welding before forming to the automotive industry-tailored blanks. The welding process is studied through the analysis of parameters optimization, metallurgical quality and induced distortions by the welding process. The clamping system and the gas protection system developed are fully described. These systems allow the minimization of common thin-sheet laser welding defects like misalignment, and zinc-coated laser welding defects like porous and zinc ventilation. The laser welding quality is accessed by DIN 8563 standard, and by tensile, microhardness and corrosion test. (Author) 8 refs

  4. A thin-lip rupture of carbon steel superheater boiler tube

    International Nuclear Information System (INIS)

    Khalil, E.O.; Alzoye, K.S.; Elwaer, A.M.

    1993-01-01

    A ruptured A 42 medium carbon steel tube was collected by the engineering department in one of our steam power stations. Inspection of ruptured tube revealed a thin - lip fracture with brownish thin layer of oxide film on inner tube surfaces. There was no evidence of pitting, the outer surfaces of the tube exhibited a general oxidized conditions. A micro section taken near the fracture surface consists of ferrite and martensite, the amount of martensite decreased as we away from the fracture surface. Presence of martensite phase in the microstructure indicates that the tube material has been overheated. An erosion corrosion mechanism in conjunction with overheated. An erosion corrosion mechanism in conjunction with overheating resulted in strength deterioration with consequent premature failure. 4 fig., 1 tab

  5. Lithographically patterned thin activated carbon films as a new technology platform for on-chip devices.

    Science.gov (United States)

    Wei, Lu; Nitta, Naoki; Yushin, Gleb

    2013-08-27

    Continuous, smooth, visibly defect-free, lithographically patterned activated carbon films (ACFs) are prepared on the surface of silicon wafers. Depending on the synthesis conditions, porous ACFs can either remain attached to the initial substrate or be separated and transferred to another dense or porous substrate of interest. Tuning the activation conditions allows one to change the surface area and porosity of the produced carbon films. Here we utilize the developed thin ACF technology to produce prototypes of functional electrical double-layer capacitor devices. The synthesized thin carbon film electrodes demonstrated very high capacitance in excess of 510 F g(-1) (>390 F cm(-3)) at a slow cyclic voltammetry scan rate of 1 mV s(-1) and in excess of 325 F g(-1) (>250 F cm(-3)) in charge-discharge tests at an ultrahigh current density of 45,000 mA g(-1). Good stability was demonstrated after 10,000 galvanostatic charge-discharge cycles. The high values of the specific and volumetric capacitances of the selected ACF electrodes as well as the capacity retention at high current densities demonstrated great potential of the proposed technology for the fabrication of various on-chip devices, such as micro-electrochemical capacitors.

  6. Fully integrated carbon nanotube composite thin film strain sensors on flexible substrates for structural health monitoring

    Science.gov (United States)

    Burton, A. R.; Lynch, J. P.; Kurata, M.; Law, K. H.

    2017-09-01

    Multifunctional thin film materials have opened many opportunities for novel sensing strategies for structural health monitoring. While past work has established methods of optimizing multifunctional materials to exhibit sensing properties, comparatively less work has focused on their integration into fully functional sensing systems capable of being deployed in the field. This study focuses on the advancement of a scalable fabrication process for the integration of multifunctional thin films into a fully integrated sensing system. This is achieved through the development of an optimized fabrication process that can create a broad range of sensing systems using multifunctional materials. A layer-by-layer deposited multifunctional composite consisting of single walled carbon nanotubes (SWNT) in a polyvinyl alcohol and polysodium-4-styrene sulfonate matrix are incorporated with a lithography process to produce a fully integrated sensing system deposited on a flexible substrate. To illustrate the process, a strain sensing platform consisting of a patterned SWNT-composite thin film as a strain-sensitive element within an amplified Wheatstone bridge sensing circuit is presented. Strain sensing is selected because it presents many of the design and processing challenges that are core to patterning multifunctional thin film materials into sensing systems. Strain sensors fabricated on a flexible polyimide substrate are experimentally tested under cyclic loading using standard four-point bending coupons and a partial-scale steel frame assembly under lateral loading. The study reveals the material process is highly repeatable to produce fully integrated strain sensors with linearity and sensitivity exceeding 0.99 and 5 {{V}}/{ε }, respectively. The thin film strain sensors are robust and are capable of high strain measurements beyond 3000 μ {ε }.

  7. Thin, Flexible Supercapacitors Made from Carbon Nanofiber Electrodes Decorated at Room Temperature with Manganese Oxide Nanosheets

    OpenAIRE

    Nataraj, S. K.; Song, Q.; Al-Muhtaseb, S. A.; Dutton, S. E.; Zhang, Q.; Sivaniah, E.

    2013-01-01

    We report the fabrication and electrochemical performance of a flexible thin film supercapacitor with a novel nanostructured composite electrode. The electrode was prepared by in situ coprecipitation of two-dimensional (2D) MnO2 nanosheets at room temperature in the presence of carbon nanofibers (CNFs). The highest specific capacitance of 142 F/g was achieved for CNFs-MnO2 electrodes in sandwiched assembly with PVA-H4SiW12O40nH2O polyelectrolyte separator. Peer Reviewed

  8. Thin, Flexible Supercapacitors Made from Carbon Nanofiber Electrodes Decorated at Room Temperature with Manganese Oxide Nanosheets

    Directory of Open Access Journals (Sweden)

    S. K. Nataraj

    2013-01-01

    Full Text Available We report the fabrication and electrochemical performance of a flexible thin film supercapacitor with a novel nanostructured composite electrode. The electrode was prepared by in situ coprecipitation of two-dimensional (2D MnO2 nanosheets at room temperature in the presence of carbon nanofibers (CNFs. The highest specific capacitance of 142 F/g was achieved for CNFs-MnO2 electrodes in sandwiched assembly with PVA-H4SiW12O40·nH2O polyelectrolyte separator.

  9. Fabrication of Carbon Nanotube Thin Films by Evaporation-Induced Self-Assembly

    OpenAIRE

    Li, Han

    2015-01-01

    In summary, we have prepared single-wall carbon nanotube (SWNT) thin films by the method of evaporation-induced self-assembly (EISA). Using the scalable two-plate or lens setups, sorts of different film types or patterns of SWNTs has been successfully fabricated directly from the evaporation of solvents and could be precisely controlled by the concentrations of SWNT in ambient conditions. The special geometry of meniscus as the capillary bridge has not only given rise to a much higher efficie...

  10. High resolution spectroscopy of H+ energy loss in thin carbon film

    International Nuclear Information System (INIS)

    Matsunami, Noriaki; Kitoh, Kenshin

    1991-05-01

    The energy loss of ∼100 keV H + transmitted through thin carbon film of ∼7 nm has been measured with the resolution of ∼20 eV. We have observed new energy loss peaks around 210 and 400 eV in addition to the normal energy loss peak around 1 keV. We find that the experimental artifacts, ionization of C K-(290 eV) and impurity inner-shells, extreme non-uniformity of films, events associated with elastic scattering are not responsible for these peaks. The origin of these low energy loss peaks will be discussed. (author)

  11. Post-foil interaction in foil-induced molecular dissociation

    International Nuclear Information System (INIS)

    Faibis, A.; Kanter, E.P.; Koenig, W.; Plesser, I.; Vager, Z.

    1985-01-01

    The authors have investigated the foil-induced dissociation of 175- 250- keV/amu CH + , NH + , and OH + , FH + and NeH + ions by coincident detection of the fragment atoms. The dissociation energies corresponding to in-foil and post-foil interactions were deduced from the measured relative flight times of the fragment pairs to a set of detectors downstream from the target. The authors considered final states consisting of a) a proton and a heavy-ion and, b) a hydrogen atom and a heavy-ion. Surprisingly, in both cases the energy released in the post-target interaction shows a similar linear increase with the charge state of the heavy partner

  12. Carbon dioxide and water adsorption on highly epitaxial Delafossite CuFeO2 thin film

    Science.gov (United States)

    Rojas, S.; Joshi, T.; Borisov, P.; Sarabia, M.; Lederman, D.; Cabrera, A. L.

    2015-03-01

    Thermal programmed desorption (TPD) of CO2 and H2O from a 200 nm thick CuFeO2 Delafossite surface was performed in a standard UHV chamber, The CuFeO2 thin film grown using Pulsed Laser Deposition (PLD) over an Al2O3 (0001) substrate with controlled O2 atmosphere resulted with highly epitaxial crystal structure. The adsorption/desorption of CO2 and H2O process was also monitored with X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). Our results revealed that carbon dioxide interacts with CuFeO2 forming Fe carbonates compounds on its surface. Hydroxides were also formed on the surface due to water presence. Using TPD data, Arrhenius plots for CO2 and water desorption were done and activation energy for desorption was obtained. Funds FONDECyT 1130372; Thanks to P. Ferrari.

  13. Ultra-Thin Optically Transparent Carbon Electrodes Produced from Layers of Adsorbed Proteins

    Science.gov (United States)

    Alharthi, Sarah A.; Benavidez, Tomas E.; Garcia, Carlos D.

    2013-01-01

    This work describes a simple, versatile, and inexpensive procedure to prepare optically transparent carbon electrodes, using proteins as precursors. Upon adsorption, the protein-coated substrates were pyrolyzed under reductive conditions (5% H2) to form ultra-thin, conductive electrodes. Because proteins spontaneously adsorb to interfaces forming uniform layers, the proposed method does not require a precise control of the preparation conditions, specialized instrumentation, or expensive precursors. The resulting electrodes were characterized by a combination of electrochemical, optical, and spectroscopic means. As a proof-of-concept, the optically-transparent electrodes were also used as substrate for the development of an electrochemical glucose biosensor. The proposed films represent a convenient alternative to more sophisticated, and less available, carbon-based nanomaterials. Furthermore, these films could be formed on a variety of substrates, without classical limitations of size or shape. PMID:23421732

  14. Preparation of selenium coatings onto beryllium foils

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-09-01

    A technique for preparing selenium films onto 50.8 microns thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. Profilometry measurements of the coatings indicate deposit thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 microns. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable thin film controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV. 15 references, 3 figures

  15. Structural, nanomechanical and variable range hopping conduction behavior of nanocrystalline carbon thin films deposited by the ambient environment assisted filtered cathodic jet carbon arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, O.S., E-mail: ospanwar@mail.nplindia.ernet.in [Polymorphic Carbon Thin Films Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi - 110 012 (India); Rawal, Ishpal; Tripathi, R.K. [Polymorphic Carbon Thin Films Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi - 110 012 (India); Srivastava, A.K. [Electron and Ion Microscopy, Sophisticated and Analytical Instruments, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi - 110 012 (India); Kumar, Mahesh [Ultrafast Opto-Electronics and Tetrahertz Photonics Group, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi - 110 012 (India)

    2015-04-15

    Highlights: • Nanocrystalline carbon thin films are grown by filtered cathodic jet carbon arc process. • Effect of gaseous environment on the properties of carbon films has been studied. • The structural and nanomechanical properties of carbon thin films have been studied. • The VRH conduction behavior in nanocrystalline carbon thin films has been studied. - Abstract: This paper reports the deposition and characterization of nanocrystalline carbon thin films by filtered cathodic jet carbon arc technique assisted with three different gaseous environments of helium, nitrogen and hydrogen. All the films are nanocrystalline in nature as observed from the high resolution transmission electron microscopic (HRTEM) measurements, which suggests that the nanocrystallites of size ∼10–50 nm are embedded though out the amorphous matrix. X-ray photoelectron spectroscopic studies suggest that the film deposited under the nitrogen gaseous environment has the highest sp{sup 3}/sp{sup 2} ratio accompanied with the highest hardness of ∼18.34 GPa observed from the nanoindentation technique. The film deposited under the helium gaseous environment has the highest ratio of the area under the Raman D peak to G peak (A{sub D}/A{sub G}) and the highest conductivity (∼2.23 S/cm) at room temperature, whereas, the film deposited under the hydrogen environment has the lowest conductivity value (2.27 × 10{sup −7} S/cm). The temperature dependent dc conduction behavior of all the nanocrystalline carbon thin films has been analyzed in the light of Mott’s variable range hopping (VRH) conduction mechanism and observed that all the films obey three dimension VRH conduction mechanism for the charge transport.

  16. Graphene oxide/carbon nanoparticle thin film based IR detector: Surface properties and device characterization

    Directory of Open Access Journals (Sweden)

    Farzana Aktar Chowdhury

    2015-10-01

    Full Text Available This work deals with the synthesis, characterization, and application of carbon nanoparticles (CNP adorned graphene oxide (GO nanocomposite materials. Here we mainly focus on an emerging topic in modern research field presenting GO-CNP nanocomposite as a infrared (IR radiation detector device. GO-CNP thin film devices were fabricated from liquid phase at ambient condition where no modifying treatments were necessary. It works with no cooling treatment and also for stationary objects. A sharp response of human body IR radiation was detected with time constants of 3 and 36 sec and radiation responsivity was 3 mAW−1. The current also rises for quite a long time before saturation. This work discusses state-of-the-art material developing technique based on near-infrared photon absorption and their use in field deployable instrument for real-world applications. GO-CNP-based thin solid composite films also offer its potentiality to be utilized as p-type absorber material in thin film solar cell, as well.

  17. Characterization of thin Zn-Ni alloy coatings electrodeposited on low carbon steel

    International Nuclear Information System (INIS)

    El Hajjami, A.; Gigandet, M.P.; De Petris-Wery, M.; Catonne, J.C.; Duprat, J.J.; Thiery, L.; Raulin, F.; Pommier, N.; Starck, B.; Remy, P.

    2007-01-01

    The characteristics of initial layer formation in alkaline bath for Zn-Ni (12-15%) alloy electrodeposition on low carbon steel plates are detected in a nanometric thickness range by electron probe microanalysis (EPMA), with both bulk sample and thin film on substrate correction procedure, glow discharge optical emission spectroscopy (GDOES) and gracing incidence X-ray diffraction (GIXRD). The Zn-Ni coatings were elaborated using either intensiostatic or potentiostatic mode. A preferential deposition of Ni, in the initial thin layer, is detected by these analyses; according to EPMA and GDOES measurements, a layer rich in nickel at the interface substrate/deposit is observed (90 wt.% Ni) and approved by GIXRD; the thin layer of Ni formed in the first moments of electrolysis greatly inhibits the Zn deposition. The initial layer depends upon the relative ease of hydrogen and metal discharge and on the different substrate surfaces involved. The electrodeposition of zinc-nickel alloys in the first stage is a normal phenomenon of codeposition, whereby nickel - the more noble metal - is deposited preferentially

  18. Domain growth of carbon nanotubes assisted by dewetting of thin catalyst precursor films

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Alok Kumar [Defence Materials and Stores R and D Establishment (DRDO), GT Road, Kanpur 208013 (India); Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India); Sachan, Priyanka; Samanta, Chandan [Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India); Mukhopadhyay, Kingsuk [Defence Materials and Stores R and D Establishment (DRDO), GT Road, Kanpur 208013 (India); Sharma, Ashutosh, E-mail: ashutos@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016 (India)

    2014-01-01

    We explore self-organized dewetting of ultrathin films of a novel metal complex as a one step surface patterning method to create nanoislands of iron, using which spatially separated carbon nanostructures were synthesized. Dewetting of ultrathin metal complex films was induced by two different methods: liquid solvent exposure and thermal annealing to engender surface patterning. For thermal dewetting, thin films of the iron oleate complex were dewetted at high temperature. In the case of liquid solvent assisted dewetting, the metal complex, mixed with a sacrificial polymer (polystyrene) was spin coated as thin films (<40 nm) and then dewetted under an optimal solution mixture consisting of methyl ethyl ketone, acetone and water. The carrier polymer was then selectively removed to produce the iron metal islands. These metal islands were used for selective growth of discrete patches of multiwall CNTs and CNFs by a chemical vapor deposition (CVD) process. Solvent induced dewetting showed clear advantages over thermal dewetting owing to reduced size of catalyst domains formed by dewetting, an improved control over CNT growth as well as in its ability to immobilize the seed particles. The generic solution mediated dewetting and pattern generation in thin films of various catalytic precursors can thus be a powerful method for selective domain growth of a variety of functional nanomaterials.

  19. Preparation of electrochromic thin films by transformation of manganese(II) carbonate

    Science.gov (United States)

    Stojkovikj, Sasho; Najdoski, Metodija; Koleva, Violeta; Demiri, Sani

    2013-10-01

    A new chemical bath method for deposition of manganese(II) carbonate thin film on electroconductive FTO glass substrates is designed. The homogeneous thin films with thickness in the range of 70 to 500 nm are deposited at about 98 °C from aqueous solution containing urea and MnCl2. The chemical process is based on a low temperature hydrolysis of the manganese complexes with urea. Three types of films are under consideration: as-deposited, annealed and electrochemically transformed thin films. The structure of the films is studied by XRD, IR and Raman spectroscopy. Electrochemical and optical properties are examined in eight different electrolytes (neutral and alkaline) and the best results are achieved in two component aqueous solution of 0.1 M KNO3 and 0.01 M KOH. It is established that the as-deposited MnCO3 film undergoes electrochemically transformation into birnessite-type manganese(IV) oxide films, which exhibit electrochromic color changes (from bright brown to pale yellow and vice versa) with 30% difference in the transmittance of the colored and bleached state at 400 nm.

  20. Iron, nitrogen and silicon doped diamond like carbon (DLC) thin films: A comparative study

    International Nuclear Information System (INIS)

    Ray, Sekhar C.; Pong, W.F.; Papakonstantinou, P.

    2016-01-01

    The X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), valence band photoemission (VB-PES) and Raman spectroscopy results show that the incorporation of nitrogen in pulsed laser deposited diamond like carbon (DLC) thin films, reverts the sp"3 network to sp"2 as evidenced by an increase of the sp"2 cluster and I_D/I_G ratio in C K-edge XANES and Raman spectra respectively which reduces the hardness/Young's modulus into the film network. Si-doped DLC film deposited in a plasma enhanced chemical vapour deposition process reduces the sp"2 cluster and I_D/I_G ratio that causes the decrease of hardness/Young's modulus of the film structure. The Fe-doped DLC films deposited by dip coating technique increase the hardness/Young's modulus with an increase of sp"3-content in DLC film structure. - Highlights: • Fe, N and Si doped DLC films deposited by dip, PLD and PECVD methods respectively • DLC:Fe thin films have higher hardness/Young's modulus than DLC:N(:Si) thin films. • sp"3 and sp"2 contents are estimated from C K-edge XANES and VB-PES measurements.

  1. Highly transparent and conductive thin films fabricated with nano-silver/double-walled carbon nanotube composites.

    Science.gov (United States)

    Lee, Shie-Heng; Teng, Chih-Chun; Ma, Chen-Chi M; Wang, Ikai

    2011-12-01

    This study develops a technique for enhancing the electrical conductivity and optical transmittance of transparent double-walled carbon nanotube (DWNT) film. Silver nanoparticles were modified with a NH(2)(CH(2))(2)SH self-assembled monolayer terminated by amino groups and subsequent surface condensation that reacted with functionalized DWNTs. Ag nanoparticles were grafted on the surface of the DWNTs. The low sheet resistance of the resulting thin conductive film on a polyethylene terephthalate (PET) substrate was due to the increased contact areas between DWNTs and work function by grafting Ag nanoparticles on the DWNT surfaces. Increasing the contact area between DWNTs and work function improved the conductivity of the DWNT-Ag thin films. The prepared DWNT-Ag thin films had a sheet resistance of 53.4 Ω/sq with 90.5% optical transmittance at a 550 nm wavelength. After treatment with HNO(3) and annealing at 150 °C for 30 min, a lower sheet resistance of 45.8 Ω/sq and a higher transmittance of 90.4% could be attained. The value of the DC conductivity to optical conductivity (σ(DC)/σ(OP)) ratio is 121.3. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Graphene oxide/carbon nanoparticle thin film based IR detector: Surface properties and device characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Farzana Aktar [Experimental Physics Division, Atomic Energy Centre, 4, Kazi Nazrul Islam Avenue, Dhaka-1000 (Bangladesh); Hossain, Mohammad Abul [Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Uchida, Koji; Tamura, Takahiro; Sugawa, Kosuke; Mochida, Tomoaki; Otsuki, Joe [College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Mohiuddin, Tariq [Department of Physics, College of Science, Sultan Qaboos University, Muscat (Oman); Boby, Monny Akter [Department of Physics, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Alam, Mohammad Sahabul, E-mail: msalam@ksu.edu.sa [Department of Physics, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Department of Chemical Engineering, College of Engineering & King Abdullah Institute for Nanotechnology, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2015-10-15

    This work deals with the synthesis, characterization, and application of carbon nanoparticles (CNP) adorned graphene oxide (GO) nanocomposite materials. Here we mainly focus on an emerging topic in modern research field presenting GO-CNP nanocomposite as a infrared (IR) radiation detector device. GO-CNP thin film devices were fabricated from liquid phase at ambient condition where no modifying treatments were necessary. It works with no cooling treatment and also for stationary objects. A sharp response of human body IR radiation was detected with time constants of 3 and 36 sec and radiation responsivity was 3 mAW{sup −1}. The current also rises for quite a long time before saturation. This work discusses state-of-the-art material developing technique based on near-infrared photon absorption and their use in field deployable instrument for real-world applications. GO-CNP-based thin solid composite films also offer its potentiality to be utilized as p-type absorber material in thin film solar cell, as well.

  3. Electrical and magnetic properties of electrodeposited nickel incorporated diamond-like carbon thin films

    Science.gov (United States)

    Pandey, B.; Das, D.; Kar, A. K.

    2015-05-01

    Nanocomposite diamond-like carbon (DLC) thin films have been synthesized by incorporating nickel (Ni) nanoparticles in DLC matrix with varying concentration of nickel. DLC and Ni-DLC thin films have been deposited on ITO coated glass substrates employing low voltage electrodeposition method. Electrical properties of the samples were studied by measuring current-voltage characteristics and dielectric properties. The current approaches toward an ohmic behavior with metal addition. This tendency of increasing ohmicity is enhanced with increase in dilution of the electrolyte. The conductivity increases with Ni addition and interestingly it continues to increase with dilution of Ni concentration in the electrolyte in the range of our study. Magnetic properties for DLC and Ni-DLC thin film samples were examined by electron paramagnetic resonance (EPR) measurements and Super Conducting Quantum Interference Device (SQUID) measurements. g-Value for DLC is 2.074, whereas it decreases to 2.055 with Ni addition in the electrolyte. This decrement arises from the increased sp2 content in DLC matrix. The magnetic moment vs. magnetic field (m-H) curves of Ni-DLC indicate superparamagnetic behavior which may be due to ferromagnetic contribution from the incorporated nickel nanoparticles in the DLC matrix. The ZFC curve of Ni-DLC after the blocking temperature shows a combined contribution of ferromagnetic, superparamagnetic and paramagnetic nature of the materials persisting up to 300 K.

  4. Iron, nitrogen and silicon doped diamond like carbon (DLC) thin films: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Sekhar C., E-mail: Raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg (South Africa); Pong, W.F. [Department of Physics, Tamkang University, Tamsui 251, New Taipei City, Taiwan (China); Papakonstantinou, P. [Nanotechnology and Integrated Bio-Engineering Centre, University of Ulster, Shore Road, Newtownabbey BT37 0QB (United Kingdom)

    2016-07-01

    The X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), valence band photoemission (VB-PES) and Raman spectroscopy results show that the incorporation of nitrogen in pulsed laser deposited diamond like carbon (DLC) thin films, reverts the sp{sup 3} network to sp{sup 2} as evidenced by an increase of the sp{sup 2} cluster and I{sub D}/I{sub G} ratio in C K-edge XANES and Raman spectra respectively which reduces the hardness/Young's modulus into the film network. Si-doped DLC film deposited in a plasma enhanced chemical vapour deposition process reduces the sp{sup 2} cluster and I{sub D}/I{sub G} ratio that causes the decrease of hardness/Young's modulus of the film structure. The Fe-doped DLC films deposited by dip coating technique increase the hardness/Young's modulus with an increase of sp{sup 3}-content in DLC film structure. - Highlights: • Fe, N and Si doped DLC films deposited by dip, PLD and PECVD methods respectively • DLC:Fe thin films have higher hardness/Young's modulus than DLC:N(:Si) thin films. • sp{sup 3} and sp{sup 2} contents are estimated from C K-edge XANES and VB-PES measurements.

  5. Amorphous Carbon Gold Nanocomposite Thin Films: Structural and Spectro-ellipsometric Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Montiel-Gonzalez, Z., E-mail: zeuzmontiel@hotmail.com [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito exterior s/n, Ciudad Universitaria, Coyoacan 04510, Mexico D.F (Mexico); Rodil, S.E.; Muhl, S. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito exterior s/n, Ciudad Universitaria, Coyoacan 04510, Mexico D.F (Mexico); Mendoza-Galvan, A. [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Unidad Queretaro, 76010 Queretaro, Queretaro (Mexico); Rodriguez-Fernandez, L. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, 04510, Mexico D.F (Mexico)

    2011-07-01

    Spectroscopic Ellipsometry was used to determine the optical and structural properties of amorphous carbon:gold nanocomposite thin films deposited by dc magnetron co-sputtering at different deposition power. The incorporation of gold as small particles distributed in the amorphous carbon matrix was confirmed by X-ray Diffraction, Rutherford Backscattering measurements and High Resolution Transmission Electron Microscopy. Based on these results, an optical model for the films was developed using the Maxwell-Garnett effective medium with the Drude-Lorentz model representing the optical response of gold and the Tauc-Lorentz model for the amorphous carbon. The gold volume fraction and particle size obtained from the fitting processes were comparable to those from the physical characterization. The analysis of the ellipsometric spectra for all the samples showed strong changes in the optical properties of the carbon films as a consequence of the gold incorporation. These changes were correlated to the structural modification observed by Raman Spectroscopy, which indicated a clustering of the sp{sup 2} phase with a subsequent decrease in the optical gap. Finally, measurements of Reflection and Transmission Spectroscopy were carried out and Transmission Electron Microscopy images were obtained in order to support the ellipsometric model results.

  6. Thin-film electroencephalographic electrodes using multi-walled carbon nanotubes are effective for neurosurgery.

    Science.gov (United States)

    Awara, Kousuke; Kitai, Ryuhei; Isozaki, Makoto; Neishi, Hiroyuki; Kikuta, Kenichiro; Fushisato, Naoki; Kawamoto, Akira

    2014-12-15

    Intraoperative morphological and functional monitoring is essential for safe neurosurgery. Functional monitoring is based on electroencephalography (EEG), which uses silver electrodes. However, these electrodes generate metal artifacts as silver blocks X-rays, creating white radial lines on computed tomography (CT) images during surgery. Thick electrodes interfere with surgical procedures. Thus, thinner and lighter electrodes are ideal for intraoperative use. The authors developed thin brain electrodes using carbon nanotubes that were formed into thin sheets and connected to electrical wires. The nanotube sheets were soft and fitted the curve of the head very well. When attached to the head using paste, the impedance of the newly developed electrodes was 5 kΩ or lower, which was similar to that of conventional metal electrodes. These electrodes can be used in combination with intraoperative CT, magnetic resonance imaging (MRI), or cerebral angiography. Somatosensory-evoked potentials, auditory brainstem responses, and visually evoked potentials were clearly identified in ten volunteers. The electrodes, without any artifacts that distort images, did not interfere with X-rays, CT, or MR images. They also did not cause skin damage. Carbon nanotube electrodes may be ideal for neurosurgery.

  7. Fabrication and microwave shielding properties of free standing polyaniline-carbon fiber thin sheets

    International Nuclear Information System (INIS)

    Joon, Seema; Kumar, Rakesh; Singh, Avanish Pratap; Shukla, Rajni; Dhawan, S.K.

    2015-01-01

    Attempt has been made to synthesize polyaniline-carbon fiber (PANI-CF) composite via in-situ emulsion polymerization using β-naphthalene sulphonic acid (NSA) which acts as both surfactant as well as dopant. Free standing PANI-CF thin sheets are prepared which have electrical conductivity ∼1.02 S/cm with improved mechanical strength and thermal stability. The scanning electron microscopy is used to study the surface morphology of the composites. Structural characterization is done by using XRD. The dielectric attributes (ε* = ε′ − iε″) of PANI-CF sheets are calculated using experimental S parameters (S 11 , S 12 ) by Nicolson Ross Wier equations. It has been demonstrated that these sheets show maximum shielding effectiveness (SE) of 31.9 dB at 12.4 GHz frequency at a thickness of 1.5 mm. Free standing PANI-CF sheets so prepared have a potential for X-band microwave absorber application. - Highlights: • Free standing polyaniline-carbon fiber thin sheets fabricated for EMI shielding. • The mechanical strength of sheets improves with phenolic resin loading. • The dielectric parameters were calculated by Nicholson Ross Wier equations. • Sheets (1.5 mm thickness) demonstrate SE of 31.9 dB at 12.4 GHz frequency. • Sheets find potential application for X-band microwave absorption

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

    Science.gov (United States)

    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.

  9. Scattering recoil coincidence spectrometry: a new experimental technique for profiling hydrogen isotopes in LOW-Z thin films

    International Nuclear Information System (INIS)

    Forster, J.S.; Leslie, J.R.; Laursen, T.

    1990-01-01

    The new technique for profiling light elements in thin, self-supporting foils, which uses a coincidence measurement over very large solid angles, has been demonstrated experimentally. A beam of 2.0 MeV 4 He particles was used to bombard films of (i) cracked ethylene and (ii) evaporated carbon which was subsequently implanted with 7.5 keV 1 H + ions to a concentration of 10 17 /cm 2 . Plots of E α vs E p clearly show the 1 H distributions in the foil. (author)

  10. Improvement in interfacial characteristics of low-voltage carbon nanotube thin-film transistors with solution-processed boron nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jun-Young; Ha, Tae-Jun, E-mail: taejunha0604@gmail.com

    2017-08-15

    Highlights: • We demonstrate the potential of solution-processed boron nitride (BN) thin films for nanoelectronics. • Improved interfacial characteristics reduced the leakage current by three orders of magnitude. • The BN encapsulation improves all the device key metrics of low-voltage SWCNT-TFTs. • Such improvements were achieved by reduced interaction of interfacial localized states. - Abstract: In this article, we demonstrate the potential of solution-processed boron nitride (BN) thin films for high performance single-walled carbon nanotube thin-film transistors (SWCNT-TFTs) with low-voltage operation. The use of BN thin films between solution-processed high-k dielectric layers improved the interfacial characteristics of metal-insulator-metal devices, thereby reducing the current density by three orders of magnitude. We also investigated the origin of improved device performance in SWCNT-TFTs by employing solution-processed BN thin films as an encapsulation layer. The BN encapsulation layer improves the electrical characteristics of SWCNT-TFTs, which includes the device key metrics of linear field-effect mobility, sub-threshold swing, and threshold voltage as well as the long-term stability against the aging effect in air. Such improvements can be achieved by reduced interaction of interfacial localized states with charge carriers. We believe that this work can open up a promising route to demonstrate the potential of solution-processed BN thin films on nanoelectronics.

  11. Hydrogen permeation through metallic foils

    International Nuclear Information System (INIS)

    Bernardi, M.I.B.; Rodrigues, J.A.

    1987-01-01

    The process of electrolytic permeation of hydrogen through metallic foils is studied. A double electrolytic cell, in glass, in which the two compartments of reaction are separated by a metallic foil to be studied, was built. As direct result, the hydrogen diffusion coefficient in the metal is obtained. The hydrogen diffusion coefficients in the palladium and, in austenitic stainless steels 304 and 304 L, used in the Angra-1 reactor, were obtained. Samples of stainless steels with and without welding, were used. (Author) [pt

  12. Design of large size segmented GEM foils and Drift PCB for CBM MUCH

    International Nuclear Information System (INIS)

    Saini, J.; Dubey, A.K.; Chattopadhyay, S.

    2016-01-01

    Triple GEM (Gas Electron Multiplier), sector shaped detectors will be used for Muon tracking in the Compressed Baryonic Matter (CBM) experiment at Anti-proton Ion Research (FAIR) facility at Darmstadt, Germany. The sizes of the detectors modules in the Muon Chambers (MUCH) are of the order of 1 meter with active area of about 75cms. Progressive pad geometry is chosen for the readout from these detectors. In construction of these chambers, three GEM foils are stacked on top of each other in a 3/2/2/2 gap configuration. The GEM foils are double layered copper clad 50μm thin Kapton foil. Each GEM foil has millions of holes on it. Foils of large surface area are prone to damages due to discharges owing to the high capacitance of the foil. Hence, these foils have their top surfaces divided into segments of about 100 sq.cm. Further segmentation may be necessary when there are high rate requirements, as in the case of CBM. For the GEM foils of CBM MUCH, a 24 segment layout has been adopted. Short-circuit in any of the GEM-holes will make entire foil un-usable. To reduce such occurrences, segment to segment isolation using opto-coupler in series with the GEM-foil segments has been introduced. Hence, a novel design for GEM chamber drift-PCB and foils has been made. In this scheme, each segment is powered and controlled individually. At the same time, the design takes into account, the space constraints, not only in x-y plane, but also in the z, due to compact assembly of MUCH detector layers

  13. Electrical and magnetic properties of electrodeposited nickel incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B., E-mail: pandey.beauty@yahoo.com [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Das, D. [UGC-DAE CSR, Sector III/LB-8, Bidhan Nagar, Kolkata 700098 (India); Kar, A.K. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

    2015-05-15

    Highlights: • Electrical and magnetic properties of DLC and Ni-DLC thin films are studied. • The ohmicity and conductivity of DLC films rise with nickel addition. • The ohmicity of Ni-DLC is enhanced with increase in dilution of electrolyte. • Dielectric loss is high for Ni-DLC and decreases with frequency till 100 kHz. • (m–H) and (m–T) curves of Ni-DLC indicate superparamagnetic behavior. - Abstract: Nanocomposite diamond-like carbon (DLC) thin films have been synthesized by incorporating nickel (Ni) nanoparticles in DLC matrix with varying concentration of nickel. DLC and Ni-DLC thin films have been deposited on ITO coated glass substrates employing low voltage electrodeposition method. Electrical properties of the samples were studied by measuring current–voltage characteristics and dielectric properties. The current approaches toward an ohmic behavior with metal addition. This tendency of increasing ohmicity is enhanced with increase in dilution of the electrolyte. The conductivity increases with Ni addition and interestingly it continues to increase with dilution of Ni concentration in the electrolyte in the range of our study. Magnetic properties for DLC and Ni-DLC thin film samples were examined by electron paramagnetic resonance (EPR) measurements and Super Conducting Quantum Interference Device (SQUID) measurements. g-Value for DLC is 2.074, whereas it decreases to 2.055 with Ni addition in the electrolyte. This decrement arises from the increased sp{sup 2} content in DLC matrix. The magnetic moment vs. magnetic field (m–H) curves of Ni-DLC indicate superparamagnetic behavior which may be due to ferromagnetic contribution from the incorporated nickel nanoparticles in the DLC matrix. The ZFC curve of Ni-DLC after the blocking temperature shows a combined contribution of ferromagnetic, superparamagnetic and paramagnetic nature of the materials persisting up to 300 K.

  14. Sixfold ring clustering in sp2-dominated carbon and carbon nitride thin films: A Raman spectroscopy study

    International Nuclear Information System (INIS)

    Abrasonis, G.; Gago, R.; Vinnichenko, M.; Kreissig, U.; Kolitsch, A.; Moeller, W.

    2006-01-01

    The atomic arrangement in sp 2 -dominated carbon (C) and carbon nitride (CN x ) thin films has been studied by Raman spectroscopy as a function of substrate temperature and, in the case of CN x , different N incorporation routes (growth methods). In this way, materials composing graphitelike, fullerenelike (FL), and paracyanogenlike structures have been compared. The results show that each type of arrangement results in a characteristic set of the Raman spectra parameters, which describe the degree of aromatic clustering, bond length, and angle distortion and order in sixfold structures. In the case of C films, the atomic structure evolves with substrate temperature from a disordered network to nanocrystalline planar graphitic configurations, with a progressive promotion in size and ordering of sixfold ring clusters. Nitrogen incorporation favors the promotion of sixfold rings in highly disordered networks produced at low temperatures, but precludes the formation of extended graphiticlike clusters at elevated substrate temperatures (>700 K). In the latter case, N introduces a high degree of disorder in sixfold ring clusters and enhances the formation of a FL microstructure. The formation and growth of aromatic clusters are discussed in terms of substrate temperature, N incorporation, growth rate, film-forming sources, and concurrent bombardment by hyperthermal particles during growth

  15. Numerical analysis of air-foil shaped fin performance in printed circuit heat exchanger in a supercritical carbon dioxide power cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho [Department of Mechanical Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Kwon, Jin Gyu [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Yoon, Sung Ho [Korea Institute of Nuclear Nonproliferation and Control, Daejeon 305-348 (Korea, Republic of); Park, Hyun Sun, E-mail: hejsunny@postech.ac.kr [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety, Daejeon 305-338 (Korea, Republic of); Cha, Jae Eun [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

    2015-07-15

    Highlights: • Staggered arrangement affects the pressure drop but does not significantly affect to the heat transfer. • The total pressure drop is reduced, but the amount of acceleration pressure drop increases while that of frictional pressure drop decreases as the horizontal number increases. • For the vertical number, the total pressure drop decreases more largely than the horizontal number. • The objective function shows that the fully staggered arrangement shows best performance. - Abstract: One of the key issues of the PCHE technology in the supercritical CO{sub 2} Brayton cycle is to achieve an efficient and compact designs to be able to enhance heat transfer and reduce pressure drop. The issue is challenging due to the complex configuration of micro-channels in the PCHE. In this study, an innovative micro-channel equipped with an array of airfoil fins is analyzed to evaluate its performance. In so doing, sensitivity analysis with various design parameters is performed to configure the optimal arrangement of airfoil fins by using CFD analysis for Supercritical Carbon dioxide Integral Experimental Loop (SCIEL) in Korean Atomic Energy Research Institute (KAERI). Dominant geometric parameters of the fin arrangement that affects to the thermal and hydraulic performances are the horizontal, vertical and staggered pitches. ANSYS ICEM CFD and ANSYS CFX are used for the grid generation and the computational calculation. CO{sub 2} properties are used by using REFPROF software database. The inlet temperature of the hot side is 618 K and that of the cold side is 585 K. The reference mass flow rate is set as 1.2 g/s for the vertical number of 2.0, which is the Reynolds number of about 30,000. The mass flow rate changes from 0.4 to 4.8 g/s in order to investigate the Reynolds number effect. The k-ε model is selected as the turbulence model. In conclusions, the results show that the optimal arrangement of airfoil fins can be examined in terms of an objective

  16. Numerical and experimental investigation of bump foil mechanical behaviour

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Cerda Varela, Alejandro Javier; Santos, Ilmar

    2014-01-01

    Corrugated foils are utilized in air foil bearings to introduce compliance and damping thus accurate mathematical predictions are important. A corrugated foil behaviour is investigated experimentally as well as theoretically. The experimental investigation is performed by compressing the foil...

  17. Substrate temperature influence on the trombogenicity in amorphous carbon nitride thin coatings

    International Nuclear Information System (INIS)

    Galeano-Osorio, D.S.; Vargas, S.; Lopez-Cordoba, L.M.; Ospina, R.; Restrepo-Parra, E.; Arango, P.J.

    2010-01-01

    Carbon nitride thin films were obtained through plasma assisted physical vapor deposition technique by pulsed arc, varying the substrate temperature and investigating the influence of this parameter on the films hemocompatibility. For obtaining approaches of blood compatibility, environmental scanning electron microscopy (ESEM) was used in order to study the platelets adherence and their morphology. Moreover, the elemental chemical composition was determined by using energy dispersive spectroscopy (EDS), finding C, N and O. The coatings hemocompatibility was evaluated by in vitro thrombogenicity test, whose results were correlated with the microstructure and roughness of the films obtained. During the films growth process, the substrate temperature was varied, obtaining coatings under different temperatures, room temperature (T room ), 100 deg. C, 150 deg. C and 200 deg. C. Parameters as interelectrodic distance, voltage, work pressure and number of discharges, were remained constant. By EDS, carbon and nitrogen were found in the films. Visible Raman spectroscopy was used, and it revealed an amorphous lattice, with graphitic process as the substrate temperature was increased. However, at a critical temperature of 150 deg. C, this tendency was broken, and the film became more amorphous. This film showed the lowest roughness, 2 ± 1 nm. This last characteristic favored the films hemocompatibility. Also, it was demonstrated that the blood compatibility of carbon nitride films obtained were affected by the I D /I G or sp 3 /sp 2 ratio and not by the absolute sp 3 or sp 2 concentration.

  18. Substrate temperature influence on the trombogenicity in amorphous carbon nitride thin coatings

    Energy Technology Data Exchange (ETDEWEB)

    Galeano-Osorio, D.S.; Vargas, S.; Lopez-Cordoba, L.M.; Ospina, R. [Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia); Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia); Arango, P.J. [Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia)

    2010-10-01

    Carbon nitride thin films were obtained through plasma assisted physical vapor deposition technique by pulsed arc, varying the substrate temperature and investigating the influence of this parameter on the films hemocompatibility. For obtaining approaches of blood compatibility, environmental scanning electron microscopy (ESEM) was used in order to study the platelets adherence and their morphology. Moreover, the elemental chemical composition was determined by using energy dispersive spectroscopy (EDS), finding C, N and O. The coatings hemocompatibility was evaluated by in vitro thrombogenicity test, whose results were correlated with the microstructure and roughness of the films obtained. During the films growth process, the substrate temperature was varied, obtaining coatings under different temperatures, room temperature (T{sub room}), 100 deg. C, 150 deg. C and 200 deg. C. Parameters as interelectrodic distance, voltage, work pressure and number of discharges, were remained constant. By EDS, carbon and nitrogen were found in the films. Visible Raman spectroscopy was used, and it revealed an amorphous lattice, with graphitic process as the substrate temperature was increased. However, at a critical temperature of 150 deg. C, this tendency was broken, and the film became more amorphous. This film showed the lowest roughness, 2 {+-} 1 nm. This last characteristic favored the films hemocompatibility. Also, it was demonstrated that the blood compatibility of carbon nitride films obtained were affected by the I{sub D}/I{sub G} or sp{sup 3}/sp{sup 2} ratio and not by the absolute sp{sup 3} or sp{sup 2} concentration.

  19. Impact of Argon gas on optical and electrical properties of Carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Arslan, E-mail: arslan.usman@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Rafique, M.S. [Department of Physics, University of Engineering & Technology, Lahore 54890 (Pakistan); Shaukat, S.F. [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Siraj, Khurram [Department of Physics, University of Engineering & Technology, Lahore 54890 (Pakistan); Ashfaq, Afshan [Institute of Nuclear Medicine and Oncology Lahore (INMOL), 54000 Pakistan (Pakistan); Anjum, Safia [Department of Physics, Lahore College for Women University (Pakistan); Imran, Muhammad; Sattar, Abdul [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan)

    2016-12-15

    Nanostructured thin films of carbon were synthesized and investigated for their electrical, optical, structural and surface properties. Pulsed Laser Deposition (PLD) technique was used for the preparation of these films under Argon gas environment. A KrF Laser (λ=248 nm) was used as source of ablation and plasma formation. It was observed that the carbon ions and the background gas environment has deep impact on the morphology as well as on the microstructure of the films. Time of Flight (TOF) method was used to determine the energies of the ablated carbon ions. The morphology of film surfaces deposited at various argon pressure was analysed using an atomic force microscope. The Raman spectroscopic measurement reveal that there is shift in phase from sp{sup 3} to sp{sup 2} and a decrease in FWHM of G band, which is a clear indication of enhanced graphitic clusters. The electrical resistivity was also reduced from 85.3×10{sup −1} to 2.57×10{sup −1} Ω-cm. There is an exponential decrease in band gap E{sub g} of the deposited films from 1.99 to 1.37 eV as a function of argon gas pressure.

  20. Computational Homogenization of Mechanical Properties for Laminate Composites Reinforced with Thin Film Made of Carbon Nanotubes

    Science.gov (United States)

    El Moumen, A.; Tarfaoui, M.; Lafdi, K.

    2018-06-01

    Elastic properties of laminate composites based Carbone Nanotubes (CNTs), used in military applications, were estimated using homogenization techniques and compared to the experimental data. The composite consists of three phases: T300 6k carbon fibers fabric with 5HS (satin) weave, baseline pure Epoxy matrix and CNTs added with 0.5%, 1%, 2% and 4%. Two step homogenization methods based RVE model were employed. The objective of this paper is to determine the elastic properties of structure starting from the knowledge of those of constituents (CNTs, Epoxy and carbon fibers fabric). It is assumed that the composites have a geometric periodicity and the homogenization model can be represented by a representative volume element (RVE). For multi-scale analysis, finite element modeling of unit cell based two step homogenization method is used. The first step gives the properties of thin film made of epoxy and CNTs and the second is used for homogenization of laminate composite. The fabric unit cell is chosen using a set of microscopic observation and then identified by its ability to enclose the characteristic periodic repeat in the fabric weave. The unit cell model of 5-Harness satin weave fabric textile composite is identified for numerical approach and their dimensions are chosen based on some microstructural measurements. Finally, a good comparison was obtained between the predicted elastic properties using numerical homogenization approach and the obtained experimental data with experimental tests.

  1. Determination of Concentration Dependent Diffusion Coefficients of Carbon in Expanded Austenite

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo; Christiansen, Thomas; Somers, Marcel A. J.

    2008-01-01

    Abstract. In the present paper various experimental procedures to experimentally determine the concentration dependent diffusion coefficient of carbon in expanded austenite are evaluated. To this end thermogravimetric carburization was simulated for various experimental conditions and the evaluated...... composition dependent diffusivity of carbon derived from the simulated experiments was compared with the input data. The most promising procedure for an accurate determination is shown to be stepwise gaseous carburizing of thin foils in a gaseous atmosphere; the finer the stepsize, the more accurate...

  2. Soil Co2 Efflux and Soil Carbon Content as Influenced by Thinning in Loblolly Pine Plantations on the Piedmont of Virginia

    OpenAIRE

    Selig, Marcus Franklin

    2003-01-01

    The thinning of loblolly pine plantations has a great potential to influence the fluxes and storage of carbon within managed stands. This study looked at the effects of thinning on aboveground carbon and mineral soil carbon storage, 14-years after the thinning of an 8-year-old loblolly pine plantation on the piedmont of Virginia. The study also examined soil respiration for one year following the second thinning of the same stand at age twenty-two. The study was conducted using three repli...

  3. Actinide Foil Production for MPACT Research

    Energy Technology Data Exchange (ETDEWEB)

    Beller, Denis

    2012-10-30

    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

  4. Transparent and flexible electrodes and supercapacitors using polyaniline/single-walled carbon nanotube composite thin films

    Science.gov (United States)

    Ge, Jun; Cheng, Guanghui; Chen, Liwei

    2011-08-01

    Large-scale transparent and flexible electronic devices have been pursued for potential applications such as those in touch sensors and display technologies. These applications require that the power source of these devices must also comply with transparent and flexible features. Here we present transparent and flexible supercapacitors assembled from polyaniline (PANI)/single-walled carbon nanotube (SWNT) composite thin film electrodes. The ultrathin, optically homogeneous and transparent, electrically conducting films of the PANI/SWNT composite show a large specific capacitance due to combined double-layer capacitance and pseudo-capacitance mechanisms. A supercapacitor assembled using electrodes with a SWNT density of 10.0 µg cm-2 and 59 wt% PANI gives a specific capacitance of 55.0 F g-1 at a current density of 2.6 A g-1, showing its possibility for transparent and flexible energy storage.

  5. Memory operation devices based on light-illumination ambipolar carbon-nanotube thin-film-transistors

    Energy Technology Data Exchange (ETDEWEB)

    Aïssa, B., E-mail: aissab@emt.inrs.ca [Qatar Environment and Energy Research Institute (QEERI), Qatar Foundation, P.O. Box 5825, Doha (Qatar); Centre Energie, Matériaux et Télécommunications, INRS, 1650, Boulevard Lionel-Boulet Varennes, Quebec J3X 1S2 (Canada); Nedil, M. [Telebec Wireless Underground Communication Laboratory, UQAT, 675, 1ère Avenue, Val d' Or, Quebec J9P 1Y3 (Canada); Kroeger, J. [NanoIntegris & Raymor Nanotech, Raymor Industries Inc., 3765 La Vérendrye, Boisbriand, Quebec J7H 1R8 (Canada); Haddad, T. [Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0B8 (Canada); Rosei, F. [Centre Energie, Matériaux et Télécommunications, INRS, 1650, Boulevard Lionel-Boulet Varennes, Quebec J3X 1S2 (Canada)

    2015-09-28

    We report the memory operation behavior of a light illumination ambipolar single-walled carbon nanotube thin film field-effect transistors devices. In addition to the high electronic-performance, such an on/off transistor-switching ratio of 10{sup 4} and an on-conductance of 18 μS, these memory devices have shown a high retention time of both hole and electron-trapping modes, reaching 2.8 × 10{sup 4} s at room temperature. The memory characteristics confirm that light illumination and electrical field can act as an independent programming/erasing operation method. This could be a fundamental step toward achieving high performance and stable operating nanoelectronic memory devices.

  6. Thin films of amorphous nitrogenated carbon a-CN{sub x}: Electron transfer and surface reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Tamiasso-Martinhon, P.; Cachet, H.; Debiemme-Chouvy, C.; Deslouis, C. [Universite Pierre et Marie Curie-Paris 6, Laboratoire Interfaces et Systemes Electrochimiques, CNRS, UPR15-LISE, 4 Place Jussieu, Paris F-75005 (France)

    2008-08-01

    The electrochemical behaviour of thin films of nitrogenated amorphous carbon a-CN{sub x} is similar to that of boron-doped diamond, with a wide potential window in aqueous media. They are elaborated by cathodic sputtering of a graphite target in an Ar-N{sub 2} active plasma for varying nitrogen contents, determined by XPS (0.06 {<=} x {<=} 0.39). Their electrochemical reactivity is sensitive to the surface state. The present study reports on the influence of electrochemical pre treatment on the electronic transfer rate of a fast redox system ferri-ferrocyanide, by focusing on the direction of the potential excursion. On the other hand, the role of both the pH and the potential on the interfacial capacitance in the presence of Na{sub 2}SO{sub 4} without redox species is documented. The results show up the sensitivity of the film surface to the electrochemical conditions. (author)

  7. Dry-Transfer of Aligned Multiwalled Carbon Nanotubes for Flexible Transparent Thin Films

    Directory of Open Access Journals (Sweden)

    Matthew Cole

    2012-01-01

    Full Text Available Herein we present an inexpensive facile wet-chemistry-free approach to the transfer of chemical vapour-deposited multiwalled carbon nanotubes to flexible transparent polymer substrates in a single-step process. By controlling the nanotube length, we demonstrate accurate control over the electrical conductivity and optical transparency of the transferred thin films. Uniaxial strains of up to 140% induced only minor reductions in sample conductivity, opening up a number of applications in stretchable electronics. Nanotube alignment offers enhanced functionality for applications such as polarisation selective electrodes and flexible supercapacitor substrates. A capacitance of 17 F/g was determined for supercapacitors fabricated from the reported dry-transferred MWCNTs with the corresponding cyclic voltagrams showing a clear dependence on nanotube length.

  8. Transparent and flexible supercapacitors with single walled carbon nanotube thin film electrodes.

    Science.gov (United States)

    Yuksel, Recep; Sarioba, Zeynep; Cirpan, Ali; Hiralal, Pritesh; Unalan, Husnu Emrah

    2014-09-10

    We describe a simple process for the fabrication of transparent and flexible, solid-state supercapacitors. Symmetric electrodes made up of binder-free single walled carbon nanotube (SWCNT) thin films were deposited onto polydimethylsiloxane substrates by vacuum filtration followed by a stamping method, and solid-state supercapacitor devices were assembled using a gel electrolyte. An optical transmittance of 82% was found for 0.02 mg of SWCNTs, and a specific capacitance of 22.2 F/g was obtained. The power density can reach to 41.5 kW · kg(-1) and shows good capacity retention (94%) upon cycling over 500 times. Fabricated supercapacitors will be relevant for the realization of transparent and flexible devices with energy storage capabilities, displays and touch screens in particular.

  9. Memory operation devices based on light-illumination ambipolar carbon-nanotube thin-film-transistors

    International Nuclear Information System (INIS)

    Aïssa, B.; Nedil, M.; Kroeger, J.; Haddad, T.; Rosei, F.

    2015-01-01

    We report the memory operation behavior of a light illumination ambipolar single-walled carbon nanotube thin film field-effect transistors devices. In addition to the high electronic-performance, such an on/off transistor-switching ratio of 10 4 and an on-conductance of 18 μS, these memory devices have shown a high retention time of both hole and electron-trapping modes, reaching 2.8 × 10 4  s at room temperature. The memory characteristics confirm that light illumination and electrical field can act as an independent programming/erasing operation method. This could be a fundamental step toward achieving high performance and stable operating nanoelectronic memory devices

  10. Functionalized carbon nanotubes in ZnO thin films for photoinactivation of bacteria

    International Nuclear Information System (INIS)

    Akhavan, O.; Azimirad, R.; Safa, S.

    2011-01-01

    Highlights: → Unfunctionalized and functionalized MWCNT/ZnO thin films were synthesized by sol-gel method. → Zn-O-C carbonaceous bonds formed in the functionalized MWCNT/ZnO thin films. → The functionalized MWCNT/ZnO had stronger photoinactivation of the bacteria than the unfunctionalize type. → 10 wt% functionalized MWCNT content had the optimum antibacterial property. - Abstract: Two types of unfunctionalized and functionalized multi-wall carbon nanotubes (MWCNTs) were prepared to be applied in fabrication of MWCNT-ZnO nanocomposite thin films with various MWCNT contents. X-ray photoelectron spectroscopy indicated formation of functional groups on surface of the functionalized MWCNTs in the MWCNT-ZnO nanocomposite. Formation of the effective carbonaceous bonds between the ZnO and the MWCNTs was also investigated through photoinactivation of Escherichia coli bacteria on surface of the both unfunctionalized and functionalized MWCNT-ZnO nanocomposites. The functionalized MWCNT-ZnO nanocomposites showed significantly stronger photoinactivation of the bacteria than the unfunctionalized ones, for all of the various MWCNT contents (from 2 to 30 wt%). While the functionalized MWCNT-ZnO nanocomposites with the optimum MWCNT content of 10 wt% inactivated whole of the bacteria after 10 min UV-visible light irradiation, the unfunctionalized ones could inactivate only 63% of the bacteria under the same conditions. The significant enhancement of the photoinactivation of the bacteria onto the surface of the functionalized MWCNT-ZnO nanocomposites was assigned to charge transfer through Zn-O-C bands formed between the Zn atoms of the ZnO film and oxygen atoms of the carboxylic functional groups of the functionalized MWCNTs.

  11. Nanocomposite metal amorphous-carbon thin films deposited by hybrid PVD and PECVD technique.

    Science.gov (United States)

    Teixeira, V; Soares, P; Martins, A J; Carneiro, J; Cerqueira, F

    2009-07-01

    Carbon based films can combine the properties of solid lubricating graphite structure and hard diamond crystal structure, i.e., high hardness, chemical inertness, high thermal conductivity and optical transparency without the crystalline structure of diamond. Issues of fundamental importance associated with nanocarbon coatings are reducing stress, improving adhesion and compatibility with substrates. In this work new nanocomposite coatings with improved toughness based in nanocrystalline phases of metals and ceramics embedded in amorphous carbon matrix are being developed within the frame of a research project: nc-MeNxCy/a-C(Me) with Me = Mo, Si, Al, Ti, etc. Carbide forming metal/carbon (Me/C) composite films with Me = Mo, W or Ti possess appropriate properties to overcome the limitation of pure DLC films. These novel coating architectures will be adopted with the objective to decrease residual stress, improve adherence and fracture toughness, obtain low friction coefficient and high wear-resistance. Nanocomposite DLC's films were deposited by hybrid technique using a PVD-Physically Vapor Deposition (magnetron sputtering) and Plasma Enhanced Chemical Vapor Deposition (PECVD), by the use of CH4 gas. The parameters varied were: deposition time, substrate temperature (180 degrees C) and dopant (Si + Mo) of the amorphous carbon matrix. All the depositions were made on silicon wafers and steel substrates precoated with a silicon inter-layer. The characterisation of the film's physico-mechanical properties will be presented in order to understand the influence of the deposition parameters and metal content used within the a-C matrix in the thin film properties. Film microstructure and film hybridization state was characterized by Raman Spectroscopy. In order to characterize morphology SEM and AFM will be used. Film composition was measured by Energy-Dispersive X-ray analysis (EDS) and by X-ray photoelectron spectroscopy (XPS). The contact angle for the produced DLC's on

  12. Formation of a highly doped ultra-thin amorphous carbon layer by ion bombardment of graphene

    Science.gov (United States)

    Piotr Michałowski, Paweł; Pasternak, Iwona; Ciepielewski, Paweł; Guinea, Francisco; Strupiński, Włodek

    2018-07-01

    Ion bombardment of graphene leads to the formation of defects which may be used to tune properties of the graphene based devices. In this work, however, we present that the presence of the graphene layer on a surface of a sample has a significant impact on the ion bombardment process: broken sp2 bonds react with the incoming ions and trap them close to the surface of the sample, preventing a standard ion implantation. For an ion bombardment with a low impact energy and significant dose (in the range of 1014 atoms cm‑2) an amorphization of the graphene layer is observed but at the same time, most of the incoming ions do not penetrate the sample but stop at the surface, thus forming a highly doped ultra-thin amorphous carbon layer. The effect may be used to create thin layers containing desired atoms if no other technique is available. This approach is particularly useful for secondary ion mass spectrometry where a high concentration of Cs at the surface of a sample significantly enhances the negative ionization probability, allowing it to reach better detection limits.

  13. Platinum nano-cluster thin film formed on glassy carbon and the application for methanol oxidation

    International Nuclear Information System (INIS)

    Chang, Gang; Oyama, Munetaka; Hirao, Kazuyuki

    2007-01-01

    As an interesting platinum nanostructured material, a Pt nano-cluster film (PtNCF) attached on glassy carbon (GC) is reported. Through the reduction of PtCl 4 2- by ascorbic acid in the presence of GC substrate, a Pt thin continuous film composed of small nano-clusters which had a further agglomerated nanostructure of small grains could be attached on the GC surface. It was found that the electrocatalytic ability of PtNCF for the methanol oxidation was apparently higher than those of the Pt nano-clusters dispersedly attached on GC or indium in oxides. In addition, the electrocatalytic performance of PtNCF per Pt amount was superior to that of Pt black on GC. These results indicate that, in spite of the continuous nanostructures, nano-grains of PtNCF worked effectively for the catalytic electrolysis. The present PtNCF can be regarded as an interesting thin film material, which can be easily prepared by one-step chemical reduction

  14. Carbon nanotubes length optimization for preparation of improved transparent and conducting thin film substrates

    Directory of Open Access Journals (Sweden)

    Mansoor Farbod

    2017-03-01

    Full Text Available Transparent and conductive thin films of multiwalled carbon nanotubes (MWCNTs with different lengths were prepared on glass substrates by the spin coating method. In order to reduce the MWCNTs length, they were functionalized. The initial length of MWCNTs (10–15 μm was reduced to 1200, 205 and 168 nm after 30, 60 and 120 min refluxing time, respectively. After post annealing at 285 °C for 24 h, the electrical and optical properties were greatly improved for functionalized MWCNT thin films. They strongly depend on the length of CNTs. The optical transmittance of the film prepared using 30 min reflux CNTs was 2.6% and 6.6% higher than that of the 60 min and 120 min refluxed samples respectively. The sheet resistance of this film showed reductions of 45% and 80% as well. The film also exhibited the least roughness. The percolative figure of merit, which is proportional to the transparency and disproportional to the sheet resistance, was found to be higher for the sample with 30 min refluxed MWCNTs.

  15. A Study on Effect of Local Wall Thinning in Carbon Steel Elbow Pipe on Elastic Stress Concentration

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Seo, Jae Seok

    2009-01-01

    Feeder pipes that connect the inlet and outlet headers to the reactor core in CANDU nuclear power plants are considered as safety Class 1 piping items. Therefore, fatigue of feeder pipes should be assessed at design stage in order to verify structural integrity during design lifetime. In accordance with the fatigue assessment result, cumulative usage factors of some feeder pipes have significant values. The feeder pipes made of SA-106 Grade B or C carbon steel have some elbows and bends. An active degradation mechanism for the carbon steel outlet feeder piping is local wall thinning due to flow-accelerated corrosion. Inspection results from plants and metallurgical examinations of removed feeders indicated the presence of localized thinning in the vicinity of the welds in the lower portion of outlet feeders, such as Grayloc hub-to-bend weld, Grayloc hub-to-elbow weld, elbow-to-elbow, and elbow-to-pipe weld. This local wall thinning can cause increase of peak stress due to stress concentration by notch effect. The increase of peak stress results in increase of cumulative usage factor. However, present fatigue assessment doesn't consider the stress concentration due to local wall-thinning. Therefore, it is necessary to assess the effect of local wall thinning on stress concentration. This study investigates the effect of local wall thinning geometry on stress concentration by performing finite element elastic stress analysis

  16. Antibacterial and Antibiofouling Properties of Light Triggered Fluorescent Hydrophobic Carbon Quantum Dots Langmuir-Blodgett Thin Films

    Czech Academy of Sciences Publication Activity Database

    Stanković, N. K.; Bodik, M.; Šiffalovič, P.; Kotlár, M.; Mičušik, M.; Špitalsky, Z.; Danko, M.; Milivojević, D. D.; Kleinová, A.; Kubát, Pavel; Capáková, Z.; Humpolíček, P.; Lehocký, M.; Todorović Marković, B. M.; Marković, Z. M.

    2018-01-01

    Roč. 6, č. 3 (2018), s. 4154-4163 ISSN 2168-0485 R&D Projects: GA ČR(CZ) GA17-05095S Institutional support: RVO:61388955 Keywords : Hydrophobic carbon quantum dots * Langmuir-Blodgett thin films * Photodynamic therapy * Singlet oxygen Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 5.951, year: 2016

  17. The Effect of Type and Concentration of Modifier in Supercritical Carbon Dioxide on Crystallization of Nanocrystalline Titania Thin Films.

    Czech Academy of Sciences Publication Activity Database

    Sajfrtová, Marie; Cerhová, Marie; Jandová, Věra; Dřínek, Vladislav; Daniš, E.; Matějová, L.

    2018-01-01

    Roč. 133, MAR 2018 (2018), s. 211-217 ISSN 0896-8446 R&D Projects: GA ČR GA14-23274S Institutional support: RVO:67985858 Keywords : titania thin film * supercritical carbon dioxide * crystallization Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.991, year: 2016

  18. Growth of Hexagonal Columnar Nanograin Structured SiC Thin Films on Silicon Substrates with Graphene–Graphitic Carbon Nanoflakes Templates from Solid Carbon Sources

    Directory of Open Access Journals (Sweden)

    Wanshun Zhao

    2013-04-01

    Full Text Available We report a new method for growing hexagonal columnar nanograin structured silicon carbide (SiC thin films on silicon substrates by using graphene–graphitic carbon nanoflakes (GGNs templates from solid carbon sources. The growth was carried out in a conventional low pressure chemical vapor deposition system (LPCVD. The GGNs are small plates with lateral sizes of around 100 nm and overlap each other, and are made up of nanosized multilayer graphene and graphitic carbon matrix (GCM. Long and straight SiC nanograins with hexagonal shapes, and with lateral sizes of around 200–400 nm are synthesized on the GGNs, which form compact SiC thin films.

  19. Zika Vaccine Development: Flavivirus Foils

    Science.gov (United States)

    2016-09-01

    Martins, Bavari, Zika Vaccine Development 1 Zika Vaccine Development: Flavivirus Foils Martins KAO, Bavari S. The current Zika virus...States government. The rapid response to Zika is perhaps the first of its kind, and it undoubtedly has been made possible by the lessons learned from...the response to the 2014 Ebola virus outbreak in West Africa. However, Zika virus is not Ebola virus. As of February 2016 there were only 296

  20. Structural and nanomechanical properties of nanocrystalline carbon thin films for photodetection

    Energy Technology Data Exchange (ETDEWEB)

    Rawal, Ishpal [Department of Physics, Kirorimal College, University of Delhi, Delhi 110007 (India); Panwar, Omvir Singh, E-mail: ospanwar@mail.nplindia.ernet.in; Tripathi, Ravi Kant; Chockalingam, Sreekumar [Polymorphic Carbon Thin Films Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Srivastava, Avanish Kumar [Electron and Ion Microscopy, Sophisticated and Analytical Instruments, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Kumar, Mahesh [Ultrafast Optoelectronics and Tetrahertz Photonics Group, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India)

    2015-05-15

    This paper reports the effect of helium gas pressure upon the structural, nanomechanical, and photoconductive properties of nanocrystalline carbon thin (NCT) films deposited by the filtered cathodic jet carbon arc technique. High-resolution transmission electron microscopy images confirm the nanocrystalline nature of the deposited films with different crystallite sizes (3–7 nm). The chemical structure of the deposited films is further analyzed by x-ray photoelectron spectroscopy and Raman spectroscopy, which suggest that the deposited films change from graphitelike to diamondlike, increasing in sp{sup 3} content, with a minor change in the dilution of the inert gas (helium). The graphitic character is regained upon higher dilution of the helium gas, whereupon the films exhibit an increase in sp{sup 2} content. The nanomechanical measurements show that the film deposited at a helium partial pressure of 2.2 × 10{sup −4} has the highest value of hardness (37.39 GPa) and elastic modulus (320.50 GPa). At a light intensity of 100 mW/cm{sup 2}, the NCT films deposited at 2.2 × 10{sup −4} and 0.1 mbar partial pressures of helium gas exhibit good photoresponses of 2.2% and 3.6%, respectively.

  1. Outdoor corrosion of zinc coated carbon steel, determined by thin layer activation

    International Nuclear Information System (INIS)

    Agostini, M.L.; Laguzzi, G.; De Cristofaro, N.; Stroosnijder, M.F.

    2001-01-01

    Thin Layer Activation was applied in the frame of a European programme addressed to the evaluation of the corrosion the behaviour of different steels. This included outdoor exposure of zinc coated carbon steel in a rural-marine climatic environment, for a period of several months. The zinc layer of specimens was 10 micrometers thick. For the TLA studies 65Zn radio nuclides were produced along the full depth of the coating, by a cyclotron accelerated deuteron beam. For quantification of the material release, activity versus depth was determined using different thickness of Zn coatings on top the carbon steel. After exposure corrosion product were removed from the surface using a pickling solution and the residual activity was determined by gamma spectrometry. The high sensitivity of the method allowed the evaluation of relatively small thickness losses (i.e. 1.2 micrometer). Thickness loss results, obtained by the TLA method, were compared with those arising from the Atomic Absorption analysis of zinc detected in the pickling solutions. A good agreement was observed between the different methods

  2. Plasma flow switch and foil implosion experiments on Pegasus II

    International Nuclear Information System (INIS)

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.R.; Forman, P.R.; Gribble, R.F.; Ladish, J.S.; Oona, H.; Parker, J.V.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

    1993-01-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10's of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy

  3. Expeditious low-temperature sintering of copper nanoparticles with thin defective carbon shells

    Science.gov (United States)

    Kim, Changkyu; Lee, Gyoungja; Rhee, Changkyu; Lee, Minku

    2015-04-01

    The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation. Isothermal oxidation and reduction treatment at 200 °C for only about 10 min yields an oxide-free copper network structure with an electrical resistivity of 25.1 μΩ cm (14.0 μΩ cm at 250 °C). Finally, conductive copper line patterns are achieved down to a 50 μm width with an excellent printing resolution (standard deviation ~4.0%) onto a polyimide substrate using screen printing of the optimized inks.The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation

  4. Magnetic collimation and metal foil filtering for electron range and fluence modulation

    International Nuclear Information System (INIS)

    Phaisangittisakul, N.; D'Souza, W.D.; Ma Lijun

    2004-01-01

    We investigated the use of magnetically collimated electron beams together with metal filters for electron fluence and range modulation. A longitudinal magnetic field collimation method was developed to reduce skin dose and to improve the electron beam penumbra. Thin metal foils were used to adjust the energies of magnetically collimated electrons. The effects for different types of foils such as Al, Be, Cu, Pb, and Ti were studied using Monte Carlo calculations. An empirical pencil beam dose calculation model was developed to calculate electron dose distributions under magnetic collimation and foil modulation. An optimization method was developed to produce conformal dose distributions for simulated targets such as a horseshoe-shaped target. Our results show that it is possible to produce an electron depth dose enhancement peak using similar techniques of producing a spread-out Bragg peak. In conclusion, our study demonstrates new aspects of using magnetic collimation and foil filtration for producing fluence and range modulated electron dose distributions

  5. Tandem accelerator transmission and life measurement of 50 keV/amu Au ions using stripper foil made by INS

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Satoshi; Takahashi, Tsutomu; Shima, Kunihiro [Tsukuba Univ., Ibaraki (Japan). Tandem Accelerator Center; Sugai, Isamu; Oyaizu, Mitsuhiro

    1996-12-01

    The role of stripper foil is the charge exchange of ions. The thickness for attaining equilibrium in charge exchange becomes thinner as ions become lower speed and heavier. Accordingly, for the stripper foil, thin foil thickness is demanded in addition to the demand of long life. The stripper foil made by INS, University of Tokyo, is recognized as its long life. In the 12 UD PELETRON tandem accelerator in University of Tsukuba, in order to meet the demand of users to use heavy ions, the use of long life stripper foil has become urgent necessity. Therefore, as for the foil made by INS, the life by Au ion irradiation and the Au ion transmission were measured four times. As to the features of the test of this time, irradiation was carried out under the severe condition for the foil of low speed Au ions, and the change of beam transmission with time lapse was observed in addition to the life. The method of measurement is explained. The preparation of foils and the determination of their thickness are reported. As the results, the lifetime of the foils made by INS and the thickness dependence and time dependence or dose dependence of the transmission of low speed, heavy Au-197 ions are described. (K.I.)

  6. Changes in Soil Carbon and Moisture over the Six Year after Thinning of a Natural Oak Forest

    Science.gov (United States)

    Kim, S.; Han, S. H.; Li, G.; Chang, H.; Kim, H. J.; Son, Y.

    2017-12-01

    The objective of this study was to assess the effects of thinning on soil carbon (C) in a natural oak forest in central Korea. The study forest received three different thinning treatments consisting of un-thinned control (UTC) and two thinning intensities (15% and 30% basal area reductions) in March in 2010. Precipitation near the study forest maintained the normal level from 2010 to 2013 (average 1,400 mm year-1), but abnormally decreased from 2014 to 2016 (average 800 mm year-1). To measure total soil C stock and soil moisture conditions, soils were collected from 0-10, 10-20, and 20-30 cm depths in June, 2010, 2013, and 2016, respectively. Soil microbial biomass C and C-cycling enzymes (β-glucosidase, cellobiohydrolase, β-xylosidase, phenol oxidase, and peroxidase) at 0-10 cm depth were determined in June, 2016. Total soil C stock at 0-30 cm depth increased throughout the study period, whereas soil moisture decreased at all depths from 2013 to 2016. Both thinning treatments had higher total soil C stock at 0-30 cm depth and moisture at 10-20 and 20-30 cm depths than the UTC in 2013 and 2016, whereas the treatments showed no effects in 2010. Microbial biomass C at 0-10 cm depth in 2016 also increased because of the thinning treatments, which was positively correlated to total soil C stock. However, any effects of thinning on C-cycling enzymes were not significant. Our results indicate that thinning could contribute to relieving the impacts of decreasing precipitation by enhancing the storage of soil moisture. Furthermore, the change in total soil C stock under thinning might result from the stimulation of microbial potential for retaining organic C as a form of biomass. This study was supported by the Ministry of Environment (2014001810002) and the National Institute of Forest Science of Korea (FM0101-2009-01).

  7. Amperometric glucose sensor based on the Ni(OH){sub 2}/Al(OH){sub 4}{sup −} electrode obtained from a thin Ni{sub 3}Al foil

    Energy Technology Data Exchange (ETDEWEB)

    Jarosz, Magdalena, E-mail: jarosz@chemia.uj.edu.pl [Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30060 Krakow (Poland); Socha, Robert P. [Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences, Niezapominajek 8, 30239 Krakow (Poland); Jóźwik, Paweł [Faculty of Advanced Technology and Chemistry, Military University of Technology, Kaliskiego 2, 00908 Warsaw (Poland); Sulka, Grzegorz D. [Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30060 Krakow (Poland)

    2017-06-30

    Highlights: • Chemical etching of Ni{sub 3}Al alloy in an acidic mixture was performed. • Electrochemical activity of samples was achieved by their oxidation in NaOH. • Ni(OH){sub 2}/Al(OH){sub 4}{sup −} electrode showed electrochemical activity towards glucose. • Synthesized material is characterized by high sensitivity and short response time. - Abstract: In this report, we present a facile and relatively fast method to roughen the surface of Ni{sub 3}Al–based intermetallic foil, and test it as an amperometric non-enzymatic glucose sensor. The alloy samples underwent chemical etching in a H{sub 3}PO{sub 4}:CH{sub 3}COOH (HAc):HNO{sub 3}:H{sub 2}O (24:1:1:7 in volume) solution in order to achieve a high surface area with more electroactive sites. The Ni(OH){sub 2}/Al(OH){sub 4}{sup −} electrode was fabricated using potential cycling technique in a highly concentrated alkaline solution. The electrodes were tested electrochemically for oxidation of glucose. We have demonstrated that Ni(OH){sub 2}/Al(OH){sub 4}{sup −} electrodes exhibit high sensitivity towards glucose detection (796 μAmM{sup -1}cm{sup -2}) and short response time (3 s) upon successive addition of glucose. Moreover, as for a non-nanometric material, prepared electrodes show a relatively good linear correlation between current density and glucose concentration (0.025–0.45 mM) and limit of detection (47.6 μM). For more in-depth characterization of presented material, electrodes were examined using scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

  8. Large-scale complementary macroelectronics using hybrid integration of carbon nanotubes and IGZO thin-film transistors.

    Science.gov (United States)

    Chen, Haitian; Cao, Yu; Zhang, Jialu; Zhou, Chongwu

    2014-06-13

    Carbon nanotubes and metal oxide semiconductors have emerged as important materials for p-type and n-type thin-film transistors, respectively; however, realizing sophisticated macroelectronics operating in complementary mode has been challenging due to the difficulty in making n-type carbon nanotube transistors and p-type metal oxide transistors. Here we report a hybrid integration of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors to achieve large-scale (>1,000 transistors for 501-stage ring oscillators) complementary macroelectronic circuits on both rigid and flexible substrates. This approach of hybrid integration allows us to combine the strength of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors, and offers high device yield and low device variation. Based on this approach, we report the successful demonstration of various logic gates (inverter, NAND and NOR gates), ring oscillators (from 51 stages to 501 stages) and dynamic logic circuits (dynamic inverter, NAND and NOR gates).

  9. Silicon nitride gradient film as the underlayer of ultra-thin tetrahedral amorphous carbon overcoat for magnetic recording slider

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guigen, E-mail: wanggghit@yahoo.com [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Kuang Xuping; Zhang Huayu; Zhu Can [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Han Jiecai [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Center for Composite Materials, Harbin Institute of Technology, Harbin 150080 (China); Zuo Hongbo [Center for Composite Materials, Harbin Institute of Technology, Harbin 150080 (China); Ma Hongtao [SAE Technologies Development (Dongguan) Co., Ltd., Dongguan 523087 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer The ultra-thin carbon films with different silicon nitride (Si-N) film underlayers were prepared. Black-Right-Pointing-Pointer It highlighted the influences of Si-N underlayers. Black-Right-Pointing-Pointer The carbon films with Si-N underlayers obtained by nitriding especially at the substrate bias of -150 V, can exhibit better corrosion protection properties - Abstract: There are higher technical requirements for protection overcoat of magnetic recording slider used in high-density storage fields for the future. In this study, silicon nitride (Si-N) composition-gradient films were firstly prepared by nitriding of silicon thin films pre-sputtered on silicon wafers and magnetic recording sliders, using microwave electron cyclotron resonance plasma source. The ultra-thin tetrahedral amorphous carbon films were then deposited on the Si-N films by filtered cathodic vacuum arc method. Compared with amorphous carbon overcoats with conventional silicon underlayers, the overcoats with Si-N underlayers obtained by plasma nitriding especially at the substrate bias of -150 V, can provide better corrosion protection for high-density magnetic recording sliders.

  10. Silicon nitride gradient film as the underlayer of ultra-thin tetrahedral amorphous carbon overcoat for magnetic recording slider

    International Nuclear Information System (INIS)

    Wang Guigen; Kuang Xuping; Zhang Huayu; Zhu Can; Han Jiecai; Zuo Hongbo; Ma Hongtao

    2011-01-01

    Highlights: ► The ultra-thin carbon films with different silicon nitride (Si-N) film underlayers were prepared. ► It highlighted the influences of Si-N underlayers. ► The carbon films with Si-N underlayers obtained by nitriding especially at the substrate bias of −150 V, can exhibit better corrosion protection properties - Abstract: There are higher technical requirements for protection overcoat of magnetic recording slider used in high-density storage fields for the future. In this study, silicon nitride (Si-N) composition-gradient films were firstly prepared by nitriding of silicon thin films pre-sputtered on silicon wafers and magnetic recording sliders, using microwave electron cyclotron resonance plasma source. The ultra-thin tetrahedral amorphous carbon films were then deposited on the Si-N films by filtered cathodic vacuum arc method. Compared with amorphous carbon overcoats with conventional silicon underlayers, the overcoats with Si-N underlayers obtained by plasma nitriding especially at the substrate bias of −150 V, can provide better corrosion protection for high-density magnetic recording sliders.

  11. The use of polyimide foils to prevent contamination from self-sputtering of {sup 252}Cf deposits in high-accuracy fission counting

    Energy Technology Data Exchange (ETDEWEB)

    Gilliam, David M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: david.gilliam@nist.gov; Yue, Andrew [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN (United States); Scott Dewey, M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2008-06-01

    It is demonstrated that a thin polyimide foil can be employed to prevent contamination from the self-sputtering of a {sup 252}Cf source under vacuum, with small energy loss of the emitted fission fragments, with very small effect on the efficiency of counting the fission fragments, and with a long lifetime of the plastic foils.

  12. The affect of erbium hydride on the conversion efficience to accelerated protons from ultra-shsort pulse laser irradiated foils

    Energy Technology Data Exchange (ETDEWEB)

    Offermann, Dustin Theodore [The Ohio State Univ., Columbus, OH (United States)

    2008-01-01

    This thesis work explores, experimentally, the potential gains in the conversion efficiency from ultra-intense laser light to proton beams using erbium hydride coatings. For years, it has been known that contaminants at the rear surface of an ultra-intense laser irradiated thin foil will be accelerated to multi-MeV. Inertial Confinement Fusion fast ignition using proton beams as the igniter source requires of about 1016 protons with an average energy of about 3MeV. This is far more than the 1012 protons available in the contaminant layer. Target designs must include some form of a hydrogen rich coating that can be made thick enough to support the beam requirements of fast ignition. Work with computer simulations of thin foils suggest the atomic mass of the non-hydrogen atoms in the surface layer has a strong affect on the conversion efficiency to protons. For example, the 167amu erbium atoms will take less energy away from the proton beam than a coating using carbon with a mass of 12amu. A pure hydrogen coating would be ideal, but technologically is not feasible at this time. In the experiments performed for my thesis, ErH3 coatings on 5 μm gold foils are compared with typical contaminants which are approximately equivalent to CH1.7. It will be shown that there was a factor of 1.25 ± 0.19 improvement in the conversion efficiency for protons above 3MeV using erbium hydride using the Callisto laser. Callisto is a 10J per pulse, 800nm wavelength laser with a pulse duration of 200fs and can be focused to a peak intensity of about 5 x 1019W/cm2. The total number of protons from either target type was on the order of 1010. Furthermore, the same experiment was performed on the Titan laser, which has a 500fs pulse duration, 150J of energy and can be focused to about 3 x 1020 W/cm2. In this experiment 1012 protons were seen from both erbium hydride and

  13. Investigations of carbon nanotubes and polyacrylonitrile composites for flexible textronics

    Science.gov (United States)

    Sowiński, J.; Wróblewski, G.; Janczak, D.; Jakubowska, M.

    2017-08-01

    Thin composite layers based on polyacrylonitrile (PAN) and carbon nanotubes (CNT) were fabricated by means of spray coating with pneumatic atomization. Research was conducted to achieve transparent and flexible electrodes. Prepared suspensions in different proportions of functional phase provided good dispersion quality of CNTs and the stability. The carbon nanotubes were dispersed in dimethylformamide and then added to polyacrylonitrile solution. Suspension was sprayed onto Polyethylene terephthalate (PET) foil. After thermal treatment, samples were mechanically and electrically tested. Thanks to carbon nanomaterials used in prepared coatings, high electrical conductivity and mechanical resistance was observed. Use of a polyacrylonitrile guarantee the flexibility of electrodes and high potential in integration with polyacrylonitrile based fabrics.

  14. Photostable epoxy polymerized carbon quantum dots luminescent thin films and the performance study

    Directory of Open Access Journals (Sweden)

    Chang Zhang

    Full Text Available High photostable epoxy polymerized carbon quantum dots (C-dots luminescent thin films were prepared and their performances were compared with the CdTe quantum dots (QDs. First, water soluble C-dots (λem = 543.60 nm were synthesized. Poly (ethylene glycol diglycidyl ether (PEG and diaminooctane were used as the polymer matrix to make the epoxy resin films. FT-IR spectra showed that there were vibration at 3448 cm−1 and 1644 cm−1 which contributed to -OH and -NH respectively. SEM observations showed that the polymerizations of the films were uniform and there were no structure defects. Mechanical tests showed the tensile modulus of C-dots composite films were 4.6, 4.9, 6.4 and 7.8 MPa respectively with corresponding 0%, 1%, 2% and 5% mass fraction of C-dots, while the tensile modulus of CdTe QDs films were 4.6 MPa under the same mass fraction of CdTe QDs. Compared with semiconductor QDs, the decay of quantum yield were 5% and 10% for the C-dots and CdTe QDs, respectively. The pictures in the continuous irradiation of 48 h showed that the C-dots film was more photostable. This study provides much helpful and profound towards the fluorescent enhancement films in the field of flexible displays. Keywords: Carbon-dots, Waterborne epoxy resin, Luminescent materials, Quantum dots displays

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

    Science.gov (United States)

    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.

  16. Technical Development Path for Gas Foil Bearings

    Science.gov (United States)

    Dellacorte, Christopher

    2016-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  17. Fission fragment assisted reactor concept for space propulsion: Foil reactor

    International Nuclear Information System (INIS)

    Wright, S.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

  18. Benefits of carbon addition on the hydrogen absorption properties of Mg-based thin films grown by Pulsed Laser Deposition

    International Nuclear Information System (INIS)

    Darok, X.; Rougier, A.; Bhat, V.; Aymard, L.; Dupont, L.; Laffont, L.; Tarascon, J.-M.

    2006-01-01

    Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200 deg. C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the co-existence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x < 20%) thin films showing a faster and easier hydrogenation

  19. Cementitious Composites Engineered with Embedded Carbon Nanotube Thin Films for Enhanced Sensing Performance

    International Nuclear Information System (INIS)

    Loh, Kenneth J; Gonzalez, Jesus

    2015-01-01

    Cementitious composites such as concrete pavements are susceptible to different damage modes, which are primarily caused by repeated loading and long-term deterioration. There is even greater concern that damage could worsen and occur more frequently with the use of heavier vehicles or new aircraft carrying greater payloads. Thus, the objective of this research is to engineer cementitious composites with capabilities of self-sensing or detecting damage. The approach was to enhance the damage sensitivity of cementitious composites by incorporating multi-walled carbon nanotubes (MWNT) as part of the mix design and during casting. However, as opposed to directly dispersing MWNTs in the cement matrix, which is the current state-of-art, MWNT-based thin films were airbrushed and coated onto sand particles. The film-coated sand was then used as part of the mix design for casting mortar specimens. Mortar specimens were subjected to compressive cyclic loading tests while their electrical properties were recorded simultaneously. The results showed that the electrical properties of these cementitious composites designed with film-coated sand exhibited extremely high strain sensitivities. The electrical response was also stable and consistent between specimens. (paper)

  20. Cementitious Composites Engineered with Embedded Carbon Nanotube Thin Films for Enhanced Sensing Performance

    Science.gov (United States)

    Loh, Kenneth J.; Gonzalez, Jesus

    2015-07-01

    Cementitious composites such as concrete pavements are susceptible to different damage modes, which are primarily caused by repeated loading and long-term deterioration. There is even greater concern that damage could worsen and occur more frequently with the use of heavier vehicles or new aircraft carrying greater payloads. Thus, the objective of this research is to engineer cementitious composites with capabilities of self-sensing or detecting damage. The approach was to enhance the damage sensitivity of cementitious composites by incorporating multi-walled carbon nanotubes (MWNT) as part of the mix design and during casting. However, as opposed to directly dispersing MWNTs in the cement matrix, which is the current state-of-art, MWNT-based thin films were airbrushed and coated onto sand particles. The film-coated sand was then used as part of the mix design for casting mortar specimens. Mortar specimens were subjected to compressive cyclic loading tests while their electrical properties were recorded simultaneously. The results showed that the electrical properties of these cementitious composites designed with film-coated sand exhibited extremely high strain sensitivities. The electrical response was also stable and consistent between specimens.

  1. Application of thin layer activation technique for monitoring corrosion of carbon steel in hydrocarbon processing environment.

    Science.gov (United States)

    Saxena, R C; Biswal, Jayashree; Pant, H J; Samantray, J S; Sharma, S C; Gupta, A K; Ray, S S

    2018-05-01

    Acidic crude oil transportation and processing in petroleum refining and petrochemical operations cause corrosion in the pipelines and associated components. Corrosion monitoring is invariably required to test and prove operational reliability. Thin Layer Activation (TLA) technique is a nuclear technique used for measurement of corrosion and erosion of materials. The technique involves irradiation of material with high energy ion beam from an accelerator and measurement of loss of radioactivity after the material is subjected to corrosive environment. In the present study, TLA technique has been used to monitor corrosion of carbon steel (CS) in crude oil environment at high temperature. Different CS coupons were irradiated with a 13 MeV proton beam to produce Cobalt-56 radioisotope on the surface of the coupons. The corrosion studies were carried out by subjecting the irradiated coupons to a corrosive environment, i.e, uninhibited straight run gas oil (SRGO) containing known amount of naphthenic acid (NA) at high temperature. The effects of different parameters, such as, concentration of NA, temperature and fluid velocity (rpm) on corrosion behaviour of CS were studied. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. A single-walled carbon nanotube thin film-based pH-sensing microfluidic chip.

    Science.gov (United States)

    Li, Cheng Ai; Han, Kwi Nam; Pham, Xuan-Hung; Seong, Gi Hun

    2014-04-21

    A novel microfluidic pH-sensing chip was developed based on pH-sensitive single-walled carbon nanotubes (SWCNTs). In this study, the SWCNT thin film acted both as an electrode and a pH-sensitive membrane. The potentiometric pH response was observed by electronic structure changes in the semiconducting SWCNTs in response to the pH level. In a microfluidic chip consisting of a SWCNT pH-sensing working electrode and an Ag/AgCl reference electrode, the calibration plot exhibited promising pH-sensing performance with an ideal Nernstian response of 59.71 mV pH(-1) between pH 3 and 11 (standard deviation of the sensitivity is 1.5 mV pH(-1), R(2) = 0.985). Moreover, the SWCNT electrode in the microfluidic device showed no significant variation at any pH value in the range of the flow rate between 0.1 and 15 μl min(-1). The selectivity coefficients of the SWCNT electrode revealed good selectivity against common interfering ions.

  3. Electromechanical interactions in a carbon nanotube based thin film field emitting diode

    International Nuclear Information System (INIS)

    Sinha, N; Mahapatra, D Roy; Sun, Y; Yeow, J T W; Melnik, R V N; Jaffray, D A

    2008-01-01

    Carbon nanotubes (CNTs) have emerged as promising candidates for biomedical x-ray devices and other applications of field emission. CNTs grown/deposited in a thin film are used as cathodes for field emission. In spite of the good performance of such cathodes, the procedure to estimate the device current is not straightforward and the required insight towards design optimization is not well developed. In this paper, we report an analysis aided by a computational model and experiments by which the process of evolution and self-assembly (reorientation) of CNTs is characterized and the device current is estimated. The modeling approach involves two steps: (i) a phenomenological description of the degradation and fragmentation of CNTs and (ii) a mechanics based modeling of electromechanical interaction among CNTs during field emission. A computational scheme is developed by which the states of CNTs are updated in a time incremental manner. Finally, the device current is obtained by using the Fowler-Nordheim equation for field emission and by integrating the current density over computational cells. A detailed analysis of the results reveals the deflected shapes of the CNTs in an ensemble and the extent to which the initial state of geometry and orientation angles affect the device current. Experimental results confirm these effects

  4. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, K., E-mail: ozeki@mx.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Frontier Research Center for Applied Atomic Sciences, 162-1 Shirakata, Toukai, Ibaraki 319-1106 (Japan); Hirakuri, K.K. [Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2011-04-15

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO{sub 2}) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO{sub 2} films and DLC/TiO{sub 2}/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO{sub 2}-coated and the DLC/TiO{sub 2}/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO{sub 2} coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO{sub 2}/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO{sub 2}/DLC film had a photocatalytic effect even though the TiO{sub 2} film was covered with the DLC film.

  5. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    International Nuclear Information System (INIS)

    Ozeki, K.; Hirakuri, K.K.; Masuzawa, T.

    2011-01-01

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO 2 ) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO 2 films and DLC/TiO 2 /DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO 2 -coated and the DLC/TiO 2 /DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO 2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO 2 /DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO 2 /DLC film had a photocatalytic effect even though the TiO 2 film was covered with the DLC film.

  6. Band gap engineering of hydrogenated amorphous carbon thin films for solar cell application

    Science.gov (United States)

    Dwivedi, Neeraj; Kumar, Sushil; Dayal, Saurabh; Rauthan, C. M. S.; Panwar, O. S.; Malik, Hitendra K.

    2012-10-01

    In this work, self bias variation, nitrogen introduction and oxygen plasma (OP) treatment approaches have been used for tailoring the band gap of hydrogenated amorphous carbon (a-C:H) thin films. The band gap of a-C:H and modified a- C:H films is varied in the range from 1.25 eV to 3.45 eV, which is found to be nearly equal to the full solar spectrum (1 eV- 3.5 eV). Hence, such a-C:H and modified a-C:H films are found to be potential candidate for the development of full spectrum solar cells. Besides this, computer aided simulation with considering variable band gap a-C:H and modified a- C:H films as window layer for amorphous silicon p-i-n solar cells is also performed by AFORS-HET software and maximum efficiency as ~14 % is realized. Since a-C:H is hard material, hence a-C:H and modified a-C:H films as window layer may avoid the use of additional hard and protective coating particularly in n-i-p configuration.

  7. Multifractal characterization of single wall carbon nanotube thin films surface upon exposure to optical parametric oscillator laser irradiation

    International Nuclear Information System (INIS)

    Ţălu, Ştefan; Marković, Zoran; Stach, Sebastian; Todorović Marković, B.; Ţălu, Mihai

    2014-01-01

    This study presents a multifractal approach, obtained with atomic force microscopy analysis, to characterize the structural evolution of single wall carbon nanotube thin films upon exposure to optical parametric oscillator laser irradiation at wavelength of 430 nm. Microstructure and morphological changes of carbon nanotube films deposited on different substrates (mica and TGX grating) were recorded by atomic force microscope. A detailed methodology for surface multifractal characterization, which may be applied for atomic force microscopy data, was presented. Multifractal analysis of surface roughness revealed that carbon nanotube films surface has a multifractal geometry at various magnifications. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of carbon nanotube films surface morphology at nanometer scale. Multifractal analysis provides different yet complementary information to that offered by traditional surface statistical parameters.

  8. Reactive magnetron sputtering of N-doped carbon thin films on quartz glass for transmission photocathode applications

    Science.gov (United States)

    Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Sasinková, V.; Boháček, P.; Arbet, J.

    2018-03-01

    N-doped carbon thin films were deposited on a silicon substrate and quartz glass by RF reactive magnetron sputtering using a carbon target and an Ar+N2 gas mixture. During the magnetron sputtering, the substrate holder temperatures was kept at 800 °C. The carbon film thickness on the silicon substrate was about 70 nm, while on the quartz glass it was in the range 15 nm – 60 nm. The elemental concentration in the films was determined by RBS and ERD. Raman spectroscopy was used to evaluate the intensity ratios I D/I G of the D and G peaks of the carbon films. The transmission photocathodes prepared were placed in the hollow-cathode assembly of a Pierce-structure DC gun to produce photoelectrons. The quantum efficiency (QE) was calculated from the laser energy and cathode charge measured. The properties of the transmission photocathodes based on semitransparent N-doped carbon thin films on quartz glass and their potential for application in DC gun technology are discussed.

  9. Laser Raman microprobe spectroscopy as a diagnostic for the characterisation of diamond and diamond like carbon (DLC) thin films

    International Nuclear Information System (INIS)

    Johnston, C.

    1990-10-01

    Invariably when manufacturing an artificial diamond film a mixture of carbon is deposited - tetragonally bonded (diamond), trigonally bonded (graphite) and other allotropic crystalline forms and amorphous carbons. This imposes a need for careful analysis to determine exactly what carbon types constitute the films. Raman spectroscopy is particularly sensitive to crystal and atomic structure and has a number of advantages which make it one of the most useful techniques for interrogating diamond and DLC thin films. Although Raman spectroscopy alone cannot fully characterise the film, it can give more information than simply what particular form of carbon or other impurities are present in the film. It can be used to determine the ratio of sp 2 to sp 3 bonding within the film, and to some extent the crystallite or domain size and the internal stress of the film. The use of laser Raman microprobe spectroscopy as a diagnostic tool in the analysis of diamond and DLC thin films is demonstrated for a variety of carbon films on various substrates and the characterisation of these films is discussed. (author)

  10. Thin films of single-walled carbon nanotubes promote human osteoblastic cells (Saos-2) proliferation in low serum concentrations

    International Nuclear Information System (INIS)

    Akasaka, Tsukasa; Yokoyama, Atsuro; Matsuoka, Makoto; Hashimoto, Takeshi; Watari, Fumio

    2010-01-01

    One strategy used for the regeneration of bone is the development of cell culture substrates and scaffolds that can control osteoblast proliferation and differentiation. In recent investigations, carbon nanotubes (CNTs) have been utilized as scaffolds for osteoblastic cell cultures; however, there are only a few reports describing the proliferation of osteoblastic cells on thin CNT films; in particular, the effects of serum concentration on cell proliferation have not been studied. In the present study, we prepared culture dishes with homogeneous thin or thick films of non-modified CNTs and examined the effect of serum concentrations on human osteoblastic cells (Saos-2) proliferation in these culture dishes. We demonstrated that the ratio of cell proliferation was strongly affected by the concentration of serum. Interestingly, single-walled carbon nanotube (SWNT) thin films were found to be the most effective substrate for the proliferation of Saos-2 cells in low concentrations of serum. Thus, thin SWNT films may be used as an effective biomaterial for the culture of Saos-2 cells in low serum concentrations.

  11. Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils

    Science.gov (United States)

    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.

  12. Nanocomposite Thin Film of Poly(3-aminobenzoic acid and Multiwalled Carbon Nanotubes Fabricated through an Electrochemical Method

    Directory of Open Access Journals (Sweden)

    Paphawadee Netsuwan

    2014-01-01

    Full Text Available The composite thin films of poly(3-aminobenzoic acid (PABA and multiwalled carbon nanotubes (MWNTs are successfully fabricated through an electrochemical method. The composite mixtures containing 50 mM of 3-aminobenzoic acid with various concentrations of MWNTs (1.0, 2.5, 5.0, 7.5, and 10 mg/mL in 0.5 M H2SO4 were prepared and used in this study. Cyclic voltammetry (CV was used for fabrication and monitoring the electropolymerization of the composite thin films with potential range of 0 to 1100 mV for 5 cycles at scan rate of 20 mV/s on indium tin oxide- (ITO-coated glass substrate. UV-vis absorption spectroscopy, atomic force microscopy (AFM, and scanning electron microscopy (SEM techniques were employed to characterize the obtained composite thin films. It was found that MWNTs can enhance the peak current of CV traces of the PABA/MWNTs composite thin films without affecting the UV-vis absorption spectra. The surface morphology of the thin films can be studied using AFM and SEM techniques.

  13. Thin-sheet zinc-coated and carbon steels laser welding

    Directory of Open Access Journals (Sweden)

    Peças, P.

    1998-04-01

    Full Text Available This paper describes the results of a research on CO2 laser welding of thin-sheet carbon steels (zinccoated and uncoated, at several thicknesses combinations. Laser welding has an high potential to be applied on sub-assemblies welding before forming to the automotive industry-tailored blanks. The welding process is studied through the analysis of parameters optimization, metallurgical quality and induced distortions by the welding process. The clamping system and the gas protection system developed are fully described. These systems allow the minimization of common thin-sheet laser welding defects like misalignement, and zinc-coated laser welding defects like porous and zinc volatilization. The laser welding quality is accessed by DIN 8563 standard, and by tensile, microhardness and corrosion tests.

    Este artigo descreve os resultados da investigação da soldadura laser de CO2 de chapa fina de acó carbono (simples e galvanizado, em diferentes combinações de espessura. A soldadura laser é um processo de elevado potencial no fabrico de tailored-blanks (sub-conjuntos para posterior enformação, constituidos por varias partes de diferentes materiais e espessuras para a indústria automóvel. São analisados os aspectos de optimização paramétrica, de qualidade metalúrgica da junta soldada e das deformações resultantes da soldadura. São descritos os mecanismos desenvolvidos de fixação das chapas e protecção gasosa, por forma a minimizar os defeitos típicos na soldadura laser de chapa fina como o desalinhamento e da soldadura laser de chapa galvanizada como os poros e a volatilização do zinco. Por fim apresentam-se resultados da avaliação da qualidade da soldadura do ponto de vista qualitativo através da norma DIN 8563, e do pontos de vista quantitativo através de ensaios de tracção, dureza e corrosão.

  14. Bench Scale Thin Film Composite Hollow Fiber Membranes for Post-Combustion Carbon Dioxide Capture

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Paul [General Electric Global Research, Niskayuna, NY (United States); Bhandari, Dhaval [General Electric Global Research, Niskayuna, NY (United States); Narang, Kristi [General Electric Global Research, Niskayuna, NY (United States); McCloskey, Pat [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); Ananthasayanam, Balajee [General Electric Global Research, Niskayuna, NY (United States); Howson, Paul [General Electric Global Research, Niskayuna, NY (United States); Lee, Julia [General Electric Global Research, Niskayuna, NY (United States); Wroczynski, Ron [General Electric Global Research, Niskayuna, NY (United States); Stewart, Frederick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Orme, Christopher [Idaho National Lab. (INL), Idaho Falls, ID (United States); Klaehn, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); McNally, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rownaghi, Ali [Georgia Inst. of Technology, Atlanta, GA (United States); Lu, Liu [Georgia Inst. of Technology, Atlanta, GA (United States); Koros, William [Georgia Inst. of Technology, Atlanta, GA (United States); Goizueta, Roberto [Georgia Inst. of Technology, Atlanta, GA (United States); Sethi, Vijay [Western Research Inst., Laramie, WY (United States)

    2015-04-01

    GE Global Research, Idaho National Laboratory (INL), Georgia Institute of Technology (Georgia Tech), and Western Research Institute (WRI) proposed to develop high performance thin film polymer composite hollow fiber membranes and advanced processes for economical post-combustion carbon dioxide (CO2) capture from pulverized coal flue gas at temperatures typical of existing flue gas cleanup processes. The project sought to develop and then optimize new gas separations membrane systems at the bench scale, including tuning the properties of a novel polyphosphazene polymer in a coating solution and fabricating highly engineered porous hollow fiber supports. The project also sought to define the processes needed to coat the fiber support to manufacture composite hollow fiber membranes with high performance, ultra-thin separation layers. Physical, chemical, and mechanical stability of the materials (individual and composite) towards coal flue gas components was considered via exposure and performance tests. Preliminary design, technoeconomic, and economic feasibility analyses were conducted to evaluate the overall performance and impact of the process on the cost of electricity (COE) for a coal-fired plant including capture technologies. At the onset of the project, Membranes based on coupling a novel selective material polyphosphazene with an engineered hollow fiber support was found to have the potential to capture greater than 90% of the CO2 in flue gas with less than 35% increase in COE, which would achieve the DOE-targeted performance criteria. While lab-scale results for the polyphosphazene materials were very promising, and the material was incorporated into hollow-fiber modules, difficulties were encountered relating to the performance of these membrane systems over time. Performance, as measured by both flux of and selectivity for CO2 over other flue gas constituents was found to deteriorate over time, suggesting a system that was

  15. Effect of the neutral charge fraction in the Coulomb explosion of H2+ ions through aluminum foils

    International Nuclear Information System (INIS)

    Denton, Cristian D.; Abril, Isabel; Barriga-Carrasco, Manuel D.; Garcia-Molina, Rafael; Lantschner, Gerardo H.; Eckardt, Juan C.; Arista, Netor R.

    2002-01-01

    The Coulomb explosion of the proton fragments dissociated from H 2 + molecules moving through thin aluminum foils has been studied by means of their energy spectra, measured in the forward direction, and by computer simulations. The covered energy range goes from 25 to 100 keV/u. Estimations of the neutral charge fraction of the fragments inside the foil have been obtained by comparison of the experimental energy spectra with the computer simulations

  16. Effect of the neutral charge fraction in the Coulomb explosion of H{sub 2}{sup +} ions through aluminum foils

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Cristian D. E-mail: cdenton@fis.utfsm.cl; Abril, Isabel; Barriga-Carrasco, Manuel D.; Garcia-Molina, Rafael; Lantschner, Gerardo H.; Eckardt, Juan C.; Arista, Netor R

    2002-06-01

    The Coulomb explosion of the proton fragments dissociated from H{sub 2}{sup +} molecules moving through thin aluminum foils has been studied by means of their energy spectra, measured in the forward direction, and by computer simulations. The covered energy range goes from 25 to 100 keV/u. Estimations of the neutral charge fraction of the fragments inside the foil have been obtained by comparison of the experimental energy spectra with the computer simulations.

  17. Ultrathin foils used for low-energy neutral atom imaging of the terrestrial magnetosphere

    International Nuclear Information System (INIS)

    Funsten, H.O.; McComas, D.J.; Barraclough, B.L.

    1993-01-01

    Magnetospheric imaging by remote detection of low-energy neutral atoms (LENAs) that are created by charge exchange between magnetospheric plasma ions and neutral geocoronal atoms has been proposed as a method to provide global information of magnetospheric dynamics. For LENA detecting, carbon foils can be implemented to (1) ionize the LENAs and electrostatically remove them from the large background of solar UV scattered by the geocorona to which LENA detectors (e.g., microchannel plates) are sensitive and (2) generate secondary electrons to provide coincidence and/or LENA trajectory information. Quantification of LENA-foil interactions are crucial in defining LENA imager performance. The authors present equilibrium charge state distributions due to foil contamination from exposure to air. Angular scattering that results from the projectile-foil interaction is quantified and is shown to be independent of the charge state distribution

  18. Optimization Forest Thinning Measures for Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China: A Case Study

    Directory of Open Access Journals (Sweden)

    Lin Hou

    2016-11-01

    Full Text Available Forest thinning is a silviculture treatment for sustainable forest management. It may promote growth of the remaining individuals by decreasing stand density, reducing competition, and increasing light and nutrient availability to increase carbon sequestration in the forest ecosystem. However, the action also increases carbon loss simultaneously by reducing carbon and other nutrient inputs as well as exacerbating soil CO2 efflux. To achieve a maximum forest carbon budget, the central composite design with two independent variables (thinning intensity and thinning residual removal rate was explored in a natural pine-oak mixed stand in the Qinling Mountains, China. The net primary productivity of living trees was estimated and soil CO2 efflux was stimulated by the Yasso07 model. Based on two years observation, the preliminary results indicated the following. Evidently chemical compounds of the litter of the tree species affected soil CO2 efflux stimulation. The thinning residual removal rate had a larger effect than thinning intensity on the net ecosystem productivity. When the selective thinning intensity and residual removal rate was 12.59% and 66.62% concurrently, the net ecosystem productivity reached its maximum 53.93 t·ha−1·year−1. The lower thinning intensity and higher thinning residual removal rated benefited the net ecosystem productivity.

  19. Electrophoretically applied dielectrics for amorphous metal foils used in pulsed power saturable reactors

    International Nuclear Information System (INIS)

    Sharp, D.J.; Harjes, H.C.; Mann, G.A.

    1989-01-01

    Amorphous metal foil-wound inductors have been tested as ferromagnetic saturable inductive elements for pulsed-power (multi-terawatt) switching modules in the inertial confinement fusion program at Sandia National Laboratories. In simulated capacitor testing premature dielectric breakdown of thin polyethylene terephthalate film insulation in the inductor windings occurs at considerably below 2500 V. This appears to be due to inadvertant dielectric damage from micro-spikes on the amorphous foil surface. Electron micrographs and dielectric breakdown data illustrate that electrophoretically-applied dielectric coatings, deposited from organic aqueous colloid dispersions, can be used to provide insulating coatings on the foil which provide a 240% improvement (6000 V) in the breakdown strength of wound amorphous foil inductors. The theory and operation of a dedicated electrophoretic continuous coating system is described. The machine was constructed and successfully applied for dielectric coating of amorphous metal foil. Additional possible applications exist for practical dielectric coating of metallic films or foils used in various commercial wound-type capacitor structures. 7 refs., 9 figs

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

    Science.gov (United States)

    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.

  1. Chromic acid anodizing of aluminum foil

    Science.gov (United States)

    Dursch, H.

    1988-01-01

    The success of the Space Station graphite/epoxy truss structure depends on its ability to endure long-term exposure to the LEO environment, primarily the effects of atomic oxygen and the temperture cycling resulting from the 94 minute orbit. This report describes the development and evaluation of chromic acid anodized (CAA) aluminum foil as protective coatings for these composite tubes. Included are: development of solar absorptance and thermal emittance properties required of Al foil and development of CAA parameters to achieve these optical properties; developing techniques to CAA 25 ft lengths of Al foil; developing bonding processes for wrapping the Al foil to graphite/epoxy tubes; and atomic oxygen testing of the CAA Al foil. Two specifications were developed and are included in the report: Chromic Acid Anodizing of Aluminum Foil Process Specification and Bonding of Anodized Aluminum Foil to Graphite/Epoxy Tubes. Results show that CAA Al foil provides and excellent protective and thermal control coating for the Space Station truss structure.

  2. Influência da energia de soldagem em uniões de lâminas finas através de laser pulsado de Nd:YAG Effect of the heat input on pulsed Nd:YAG laser welding of thin foil

    Directory of Open Access Journals (Sweden)

    Vicente A. Ventrella

    2010-12-01

    as an important manufacturing process. It can be performed using either pulsed or continuous lasers. A pulsed laser can be used to create weld seams in thin foils by means of overlapping pulses. Typical problems in lap joint welding of thin foils for sealing components in corrosive environment applications include excessive distortion, absence of intimate contact between couple, melt drop through and high level of residual stress. Pulsed laser processing is expected to be the method of choice because it allows more precise heat control compared with continuous laser processing. Experimental investigations were carried out using a pulsed neodymium: yttrium aluminum garnet laser welding to examine the influence of the pulse energy in the characteristics of the weld fillet. The pulse energy was varied from 1.0 to 2.25 J at an increment of 0.25 J and 4 ms pulse duration. The base material used for this study was the AISI 316L stainless steel foil with 100µm thickness. The welds were analyzed by optical microscopy, tensile shear tests and micro hardness. The results indicated that pulse energy control is of considerable importance for thin foil weld quality since it can generate good mechanical properties and discontinuities free weld joints. The ultimate tensile strength of the welded joints increased at first and then decreased with the pulse energy increasing. The process showed very sensitive to the gap between couple.

  3. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  4. Electron transport determines the electrochemical properties of tetrahedral amorphous carbon (ta-C) thin films

    International Nuclear Information System (INIS)

    Palomäki, Tommi; Wester, Niklas; Caro, Miguel A.; Sainio, Sami; Protopopova, Vera; Koskinen, Jari; Laurila, Tomi

    2017-01-01

    Amorphous carbon based electrodes are very promising for electrochemical sensing applications. In order to better understand their structure-function relationship, the effect of film thickness on the electrochemical properties of tetrahedral amorphous carbon (ta-C) electrodes was investigated. ta-C thin films of 7, 15, 30, 50 and 100 nm were characterized in detail with Raman spectroscopy, transmission electron microscopy (TEM), conductive atomic force microscopy (c-AFM), scanning tunneling spectroscopy (STS) and X-ray absorption spectroscopy (XAS) to assess (i) the surface properties of the films, (ii) the effect of film thickness on their structure and electrical properties and (iii) the subsequent correlation with their electrochemistry. The electrochemical properties were investigated by cyclic voltammetry (CV) using two different outer-sphere redox probes, Ru(NH 3 ) 6 3+/2+ and FcMeOH, and by electrochemical impedance spectroscopy (EIS). Computational simulations using density functional theory (DFT) were carried out to rationalize the experimental findings. The characterization results showed that the sp 2 /sp 3 ratio increased with decreasing ta-C film thickness. This correlated with a decrease in mobility gap value and an increase in the average current through the films, which was also consistent with the computational results. XAS indicated that the surface of the ta-C films was always identical and composed of a sp 2 -rich layer. The CV measurements indicated reversible reaction kinetics for both outer-sphere redox probes at 7 and 15 nm ta-C films with a change to quasi-reversible behavior at a thickness of around 30 nm. The charge transfer resistance, obtained from EIS measurements, decreased with decreasing film thickness in accordance with the CV results. Based on the characterization and electrochemical results, we conclude that the reaction kinetics in the case of outer-sphere redox systems is determined mainly by the electron transport through the

  5. Impact of the difference in power frequency on diamond-like carbon thin film coating over 3-dimensional objects

    Energy Technology Data Exchange (ETDEWEB)

    Nakaya, Masaki, E-mail: m-nakaya@kirin.co.jp [Packaging Technology Development Center, Technology Development Department, Kirin Brewery Co., Ltd., 1-17-1 Namamugi, Tsurumi-ku, Yokohama, Kanagawa 230-8682 (Japan); Shimizu, Mari [Packaging Technology Development Center, Technology Development Department, Kirin Brewery Co., Ltd., 1-17-1 Namamugi, Tsurumi-ku, Yokohama, Kanagawa 230-8682 (Japan); Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)

    2014-08-01

    With a type of capacitatively coupled plasma enhanced chemical vapor deposition (PECVD) technique, where two specially designed electrodes face to each other, the inner surface of hollow 3-dimensional objects such as poly(ethylene terephthalate) (PET) bottles can be coated with diamond-like carbon (DLC) thin film. DLC-coated PET bottles obtained with this technique have an enhanced gas barrier property, and therefore are applicable to industrial use such as for the extension of the shelf-life of contents sensitive to gas permeation. In this paper, the impact of power frequency ranging from 2.5 to 13.56 MHz was studied in order to research the behavior of plasma inside PET bottles and resultant properties. Different power frequency turned out to be influential on gas barrier property, the overall and distribution of tint, and adhesion between DLC and PET substrate. In addition, positron annihilation turned out to be powerful tool for the comparison of different coating conditions because it clarifies the homogeneity of DLC thin films through providing information on overall structure and thickness of them. These findings can be used for the optimization not only in the beverage PET bottle application, but also in other capacitatively coupled PECVD devices. - Highlights: • We demonstrated an effective methodology for the homogeneity of thin films. • We described the influence of power frequency on plasma and resultant thin film. • Diamond-like carbon coated on poly(ethylene terephthalate) bottles was used. • Different frequency provided homogenous thin films based on the above methodology. • For the industrial performance of the bottles, optimization was found at 6 MHz.

  6. Impact of the difference in power frequency on diamond-like carbon thin film coating over 3-dimensional objects

    International Nuclear Information System (INIS)

    Nakaya, Masaki; Shimizu, Mari; Uedono, Akira

    2014-01-01

    With a type of capacitatively coupled plasma enhanced chemical vapor deposition (PECVD) technique, where two specially designed electrodes face to each other, the inner surface of hollow 3-dimensional objects such as poly(ethylene terephthalate) (PET) bottles can be coated with diamond-like carbon (DLC) thin film. DLC-coated PET bottles obtained with this technique have an enhanced gas barrier property, and therefore are applicable to industrial use such as for the extension of the shelf-life of contents sensitive to gas permeation. In this paper, the impact of power frequency ranging from 2.5 to 13.56 MHz was studied in order to research the behavior of plasma inside PET bottles and resultant properties. Different power frequency turned out to be influential on gas barrier property, the overall and distribution of tint, and adhesion between DLC and PET substrate. In addition, positron annihilation turned out to be powerful tool for the comparison of different coating conditions because it clarifies the homogeneity of DLC thin films through providing information on overall structure and thickness of them. These findings can be used for the optimization not only in the beverage PET bottle application, but also in other capacitatively coupled PECVD devices. - Highlights: • We demonstrated an effective methodology for the homogeneity of thin films. • We described the influence of power frequency on plasma and resultant thin film. • Diamond-like carbon coated on poly(ethylene terephthalate) bottles was used. • Different frequency provided homogenous thin films based on the above methodology. • For the industrial performance of the bottles, optimization was found at 6 MHz

  7. A study of the chemical, mechanical, and surface properties of thin films of hydrogenated amorphous carbon

    Energy Technology Data Exchange (ETDEWEB)

    Vandentop, G.J.

    1990-07-01

    Amorphous hydrogenated carbon (a-C:H) films were studied with the objective of elucidating the nucleation and growth mechanisms, and the origin of their unique physical properties. The films were deposited onto Si(100) substrates both on the powered (negatively self-biased) and on the grounded electrodes from methane in an rf plasma (13.56 MHz) at 65 mTorr and 300 to 370 K. The films produced at the powered electrode exhibited superior mechanical properties, such as high hardness. A mass spectrometer was used to identify neutral species and positive ions incident on the electrodes from the plasma, and also to measure ion energies. The effect of varying ion energy flux on the properties of a-C:H films was investigated using a novel pulsed biasing technique. It was demonstrated that ions were not the dominant deposition species as the total ion flux measured was insufficient to account for the observed deposition rate. The interface between thin films of a-C:H and silicon substrates was investigated using angle resolved x-ray photoelectron spectroscopy. A silicon carbide layer was detected at the interface of a hard a-C:H film formed at the powered electrode. At the grounded electrode, where the kinetic energy is low, no interfacial carbide layer was observed. Scanning tunneling microscopy and high energy electron energy loss spectroscopy was used to investigate the initial stages of growth of a-C:H films. On graphite substrates, films formed at the powered electrode were observed to nucleate in clusters approximately 50 {Angstrom} in diameter, while at the grounded electrode no cluster formation was observed. 58 figs.

  8. Ultralow field emission from thinned, open-ended, and defected carbon nanotubes by using microwave hydrogen plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jian-Hua, E-mail: jhdeng1983@163.com [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Lin; Wang, Fan-Jie; Yu, Bin; Li, Guo-Zheng; Li, De-Jun [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Guo-An [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China)

    2015-01-01

    Graphical abstract: Thinned, open-ended, and defected carbon nanotubes were prepared by using hydrogen plasma processing. The processed carbon nanotubes have far better field emission performance than that of the pristine ones. - Highlights: • CVD prepared CNT arrays were processed by microwave hydrogen plasma. • Thinned, open-ended, and defected CNTs were obtained. • Processed CNTs have far better field emission performance than the pristine ones. • Processed CNTs have applicable emission stability after being perfectly aged. - Abstract: Ultralow field emission is achieved from carbon nanotubes (CNTs) by using microwave hydrogen plasma processing. After the processing, typical capped CNT tips are removed, with thinned, open-ended, and defected CNTs left. Structural analyses indicate that the processed CNTs have more SP{sup 3}-hybridized defects as compared to the pristine ones. The morphology of CNTs can be readily controlled by adjusting microwave powers, which change the shape of CNTs by means of hydrogen plasma etching. Processed CNTs with optimal morphology are found to have an ultralow turn-on field of 0.566 V/μm and threshold field of 0.896 V/μm, much better than 0.948 and 1.559 V/μm of the as-grown CNTs, respectively. This improved FE performance is ascribed to the structural changes of CNTs after the processing. The thinned and open-ended shape of CNTs can facilitate electron tunneling through barriers and additionally, the increased defects at tube walls can serve as new active emission sites. Furthermore, our plasma processed CNTs exhibit excellent field emission stability at a large emission current density of 10.36 mA/cm{sup 2} after being perfectly aged, showing promising prospects in applications as high-performance vacuum electron sources.

  9. Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands

    Science.gov (United States)

    Matthew D. Powers; Randall K. Kolka; John B. Bradford; Brian J. Palik; Shawn Fraver; Martin F. Jurgensen

    2012-01-01

    Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned...

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

    Science.gov (United States)

    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.

  11. Thin and flexible all-solid supercapacitor prepared from novel single wall carbon nanotubes/polyaniline thin films obtained in liquid-liquid interfaces

    Science.gov (United States)

    de Souza, Victor Hugo Rodrigues; Oliveira, Marcela Mohallem; Zarbin, Aldo José Gorgatti

    2014-08-01

    The present work describes for the first time the synthesis and characterization of single wall carbon nanotubes/polyaniline (SWNTs/PAni) nanocomposite thin films in a liquid-liquid interface, as well as the subsequent construction of a flexible all-solid supercapacitor. Different SWNTs/PAni nanocomposites were prepared by varying the ratio of SWNT to aniline, and the samples were characterized by scanning and transmission electron microscopy, Raman and UV-Vis spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The pseudo-capacitive behavior of the nanocomposites was evaluated by charge/discharge galvanostatic measurements. The presence of the SWNTs affected the electronic and vibrational properties of the polyaniline and also improved the pseudo-capacitive behavior of the conducting polymer. A very thin and flexible all-solid device was manufactured using two electrodes (polyethylene terephthalate-PET covered with the SWNT/PAni nanocomposite separated by a H2SO4-PVA gel electrolyte). The pseudo-capacitive behavior was characterized by a volumetric specific capacitance of approximately 76.7 F cm-3, even under mechanical deformation, indicating that this nanocomposite has considerable potential for application in new-generation energy storage devices.

  12. Adhesion enhancement of diamond-like carbon thin films on Ti alloys by incorporation of nanodiamond particles

    International Nuclear Information System (INIS)

    Zhang, C.Z.; Tang, Y.; Li, Y.S.; Yang, Q.

    2013-01-01

    Coating adherent diamond-like carbon (DLC) thin films directly on Ti alloys is technologically difficult. This research incorporates nanodiamond particles to form a diamond/DLC composite interlayer to enhance the adhesion of DLC thin films on Ti6Al4V substrates. Initially, nanodiamond particles were deposited on Ti6Al4V substrates by microwave plasma enhanced chemical vapor deposition from a methane–hydrogen gas mixture. A DLC thin film was then deposited, on top of the nanodiamond particles, by direct ion beam deposition. Scanning electron microscopy, Atomic force microscopy, X-ray Diffraction and Raman spectroscopy were used to characterize the microstructure and chemical bonding of the deposited particles and films, and Rockwell indentation testing was used to evaluate the adhesion of the deposited films. The results indicate that the pre-deposited nanodiamond particles significantly enhance the interfacial adhesion between the DLC thin film and the Ti6Al4V substrate, possibly by enhanced interfacial bonding, mechanical interlocking, and stress relief. - Highlights: ► Nanodiamond particles were deposited on Ti6Al4V before DLC deposition. ► Diamond/DLC composite film was formed by incorporation of nanodiamond particles. ► Greatly enhanced adhesion of diamond/DLC composite film on Ti6Al4V was achieved. ► Enhanced adhesion is by increased interfacial bonding and mechanical interlocking

  13. Adhesion enhancement of diamond-like carbon thin films on Ti alloys by incorporation of nanodiamond particles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.Z.; Tang, Y. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, Canada S7N 5A9 (Canada); Li, Y.S. [Plasma Physics Laboratory, University of Saskatchewan, 116 Science Place, Saskatoon, SK, Canada S7N 5E2 (Canada); Yang, Q., E-mail: qiaoqin.yang@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, Canada S7N 5A9 (Canada)

    2013-01-01

    Coating adherent diamond-like carbon (DLC) thin films directly on Ti alloys is technologically difficult. This research incorporates nanodiamond particles to form a diamond/DLC composite interlayer to enhance the adhesion of DLC thin films on Ti6Al4V substrates. Initially, nanodiamond particles were deposited on Ti6Al4V substrates by microwave plasma enhanced chemical vapor deposition from a methane–hydrogen gas mixture. A DLC thin film was then deposited, on top of the nanodiamond particles, by direct ion beam deposition. Scanning electron microscopy, Atomic force microscopy, X-ray Diffraction and Raman spectroscopy were used to characterize the microstructure and chemical bonding of the deposited particles and films, and Rockwell indentation testing was used to evaluate the adhesion of the deposited films. The results indicate that the pre-deposited nanodiamond particles significantly enhance the interfacial adhesion between the DLC thin film and the Ti6Al4V substrate, possibly by enhanced interfacial bonding, mechanical interlocking, and stress relief. - Highlights: ► Nanodiamond particles were deposited on Ti6Al4V before DLC deposition. ► Diamond/DLC composite film was formed by incorporation of nanodiamond particles. ► Greatly enhanced adhesion of diamond/DLC composite film on Ti6Al4V was achieved. ► Enhanced adhesion is by increased interfacial bonding and mechanical interlocking.

  14. A study for anticorrosion and tribological behaviors of thin/thick diamond-like carbon films in seawater

    Science.gov (United States)

    Ye, Yewei; Jia, Shujuan; Zhang, Dawei; Liu, Wei; Zhao, Haichao

    2018-03-01

    The thin and thick diamond-like carbon (DLC) films were prepared by unbalanced magnetron sputtering technique on 304L stainless steels and (100) silicon wafers. Microstructure, mechanical, corrosion and tribological properties were systematically investigated by SEM, Raman, nanoindenter, scratch tester, modulab electrochemical workstation and R-tec multifunctional tribological tester. Results showed that the adhesion force presented a descending trend with the growth in soaking time. The adhesion force of the thin DLC film with high residual compressive stress (‑3.72 GPa) was higher than that of the thick DLC film (‑2.96 GPa). During the corrosion test, the thick DLC film showed a higher impendence and a lower corrosion current density than the thin DLC film, which is attributed to the barrier action of large thickness. Compared to bare 304L substrate, the friction coefficients and wear rates of DLC films in seawater were obviously decreased. Meanwhile, the thin DLC film with ideal residual compressive stress, super adhesion force and good plastic deformation resistance revealed an excellent anti-wear ability in seawater.

  15. Analysis of Mechanical Properties for GEM Foil

    CERN Document Server

    Chin, Yuk Ming

    2016-01-01

    In view of new assembly technique of the GEM detector; in which three foils stack is stretched to get the uniform gaps among the foils. We studied the mechanical properties of the foil material. We conditioned the samples in different environments to make them extra dry and wet. As holes are the major source of the charge amplification their deformation can effect the detector performance. Therefore in our studies we also studied at which level of the stress the holes deformation is seen. These tensile and holes deformation studies can help to optimize the stress during detector assembly.

  16. Influence of silver incorporation on the structural and electrical properties of diamond-like carbon thin films.

    Science.gov (United States)

    Dwivedi, Neeraj; Kumar, Sushil; Carey, J David; Tripathi, R K; Malik, Hitendra K; Dalai, M K

    2013-04-10

    A simple approach is proposed for obtaining low threshold field electron emission from large area diamond-like carbon (DLC) thin films by sandwiching either Ag dots or a thin Ag layer between DLC and nitrogen-containing DLC films. The introduction of silver and nitrogen is found to reduce the threshold field for emission to under 6 V/μm representing a near 46% reduction when compared with unmodified films. The reduction in the threshold field is correlated with the morphology, microstructure, interface, and bonding environment of the films. We find modifications to the structure of the DLC films through promotion of metal-induced sp2 bonding and the introduction of surface asperities, which significantly reduce the value of the threshold field. This can lead to the next-generation, large-area simple and inexpensive field emission devices.

  17. Effect of helium gas pressure on dc conduction mechanism and EMI shielding properties of nanocrystalline carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rawal, Ishpal, E-mail: rawalishpal@gmail.com [Department of Physics, Kirori Mal College, University of Delhi, Delhi 110007 (India); Panwar, O.S., E-mail: ospanwar@mail.nplindia.ernet.in [Polymorphic Carbon Thin Films Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Tripathi, R.K. [Polymorphic Carbon Thin Films Group, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Singh, Avanish Pratap; Dhawan, S.K. [Polymeric and Soft Materials Group, Physics Engineering of Carbon, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Srivastava, A.K. [Electron and Ion Microscopy, Sophisticated and Analytical Instruments, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India)

    2015-05-05

    This paper reports the effect of helium partial pressures ∼1.2 × 10{sup −5} (base pressure), 1.4 × 10{sup −4}, 8.6 × 10{sup −3} and 0.1 mbar on the variable range hopping conduction in nanocrystalline carbon thin films deposited by filtered cathodic jet carbon arc technique. High resolution transmission electron microscopy studies suggest the random distribution of nanocrystallites (∼3–7 nm) in the amorphous matrix. The DC conduction behavior of the deposited nanocrystalline films has been studied in the light of Mott's variable range hopping (VRH) model and found to obey three dimensional VRH conduction. The randomly distributed nanocrystallites in amorphous matrix may lead to change in the distribution of density of states near Fermi level and hence, the conduction behavior. The enhanced electrical conductivity of the deposited films due to the helium environment makes them suitable for electromagnetic interference shielding applications. The sample deposited at a helium partial pressure of 0.1 mbar has a value of shielding effectiveness ∼7.84 dB at 18 GHz frequency. - Highlights: • Nanocrystalline carbon thin films (NCTF) has been deposited by FCJCA technique. • Effect of helium gas pressure has been studied on the properties of NCTF. • Investigation of EMI shielding properties of NCTF has been carried out.

  18. Study of nuclear tracks on different polycarbonate foils and their feasibility for use in personnel monitoring

    International Nuclear Information System (INIS)

    Jayalakshmi, V.; Rohatgi, Rupali; Sathian, Deepa; Marathe, P.K.; Nair, Sarala; Chourasiya, G.; Kannan, S.

    2009-01-01

    CR-39 (PDAC) a solid state nuclear track detector, is used as a routine personnel monitor. 1800 workers are being monitored quarterly for fast neutron using CR-39 foils. These foils procured from Pershore Mouldings, UK are very expensive and indigenous development will make the foils cost effective. The aim of this paper is to find a suitable alternative to the imported CR-39 foils for use in personnel monitoring. The foils from three different manufacturers have been compared with CR-39 foils from Pershore Moulding, UK, presently in use. Out of the three, only sample no 1 is promising. It has a background and sensitivity comparable with CR-39 presently used. The sample 2 is CR-39 being developed in India, has a relatively high background and poor sensitivity. Efforts are being made to improve the quality of this sample. The sample 3 was a poly carbonate from local manufacturer which produced very few tracks and the standard deviation of track counts was very large and hence not useful for personnel monitoring. (author)

  19. Effect of thickness of foil strippers in transmission of beams through 15 UD pelletron accelerator at IUAC

    International Nuclear Information System (INIS)

    Ojha, S.; Pankaj Kumar; Gargari, S.; Joshi, R.; Abhilash; Kabiraj, D.; Chopra, S.

    2009-01-01

    15 UD Pelletron accelerator at IUAC, New Delhi is equipped with a foil stripper and a gas stripper at high voltage terminal. Besides these, we have foil stripper assemblies at High Energy Dead Section (HEDS) of Pelletron and after analyser magnet. Incoming negative ion looses electrons when they pass through the strippers at terminal and becomes positively charged. The next foil stripper at HEDS increases the positive charge state of ion by removing more electrons which helps in delivering beams at higher energy. Typical thickness of carbon foils loaded in the foil stripper assembly in the terminal is around 4 microgram per square centimetre (4 μg/cm 2 ). Thicker foils were installed in the terminal assembly to study the effect of thickness of foil on charge state distribution and transmission of ion beams. Charge state distribution of ions produced out of molecular beam was also studied. In this paper we present and discuss the results and observations with thicker foils on ion as well as molecular beams. (author)

  20. SCIAMACHY WFM-DOAS XCO2: comparison with CarbonTracker XCO2 focusing on aerosols and thin clouds

    Directory of Open Access Journals (Sweden)

    J. P. Burrows

    2012-08-01

    Full Text Available Carbon dioxide (CO2 is the most important greenhouse gas whose atmospheric loading has been significantly increased by anthropogenic activity leading to global warming. Accurate measurements and models are needed in order to reliably predict our future climate. This, however, has challenging requirements. Errors in measurements and models need to be identified and minimised. In this context, we present a comparison between satellite-derived column-averaged dry air mole fractions of CO2, denoted XCO2, retrieved from SCIAMACHY/ENVISAT using the WFM-DOAS (weighting function modified differential optical absorption spectroscopy algorithm, and output from NOAA's global CO2 modelling and assimilation system CarbonTracker. We investigate to what extent differences between these two data sets are influenced by systematic retrieval errors due to aerosols and unaccounted clouds. We analyse seven years of SCIAMACHY WFM-DOAS version 2.1 retrievals (WFMDv2.1 using CarbonTracker version 2010. We investigate to what extent the difference between SCIAMACHY and CarbonTracker XCO2 are temporally and spatially correlated with global aerosol and cloud data sets. For this purpose, we use a global aerosol data set generated within the European GEMS project, which is based on assimilated MODIS satellite data. For clouds, we use a data set derived from CALIOP/CALIPSO. We find significant correlations of the SCIAMACHY minus CarbonTracker XCO2 difference with thin clouds over the Southern Hemisphere. The maximum temporal correlation we find for Darwin, Australia (r2 = 54%. Large temporal correlations with thin clouds are also observed over other regions of the Southern Hemisphere (e.g. 43% for South America and 31% for South Africa. Over the Northern Hemisphere the temporal correlations are typically much lower. An exception is India, where large temporal correlations with clouds and aerosols have also been found. For all other regions the temporal correlations with

  1. Local deposition of Copper on Aluminum based MWT Back Contact Foil using Cold Spray Technology

    Energy Technology Data Exchange (ETDEWEB)

    Goris, M.J.A.A.; Bennett, I.J.; Eerenstein, W. [ECN Solar Energy, Petten (Netherlands)

    2013-11-15

    MWT cell and module technology has been shown to result in modules with up to 5% higher power output than H-pattern modules and to be suitable for use with thin and fragile cells. In this study, the use of a low cost conductive back-sheet with aluminium as the current carrier in combination with locally applied copper (5 to 30 {mu}m) using the cold spray method is benchmarked against a standard PVF-PET-copper foil in 2 x 2 cell modules. Cell to module losses and reliability during climate chamber tests according to IEC61215 ed. 2, are comparable to module made with the standard foil. Optimizing the cold spray process can result in a cost reduction of more than a factor 10 of the current carrying component, when compared to a full copper conductive back-sheet foil.

  2. The Anomalous Currents In The Front Foils of the JET Lost Alpha Diagnostic KA-2

    International Nuclear Information System (INIS)

    Cecil, F.E.; Kiptily, V.; Salmi, A.; Horton, A.; Fullard, K.; Murari, A.; Darrow, D.; Hill, K.

    2011-01-01

    We have examined the observed currents in the front foils of the JET Faraday cup lost alpha particle diagnostic KA-2. In particular, we have sought to understand the currents during Ohmic plasmas for which the ion flux at the detectors was initially assumed to be negligible. We have considered two sources of this current: plasma ions (both deuterium and impurity) in the vicinity of the detector (including charge exchange neutrals) and photoemission from scattered UV radiation. Based upon modeling and empirical observation, the latter source appears most likely and, moreover, seems to be applicable to the currents in the front foil during ELMy H-mode plasmas. A very thin gold or nickel foil attached to the present detector aperture is proposed as a solution to this problem, and realistic calculations of expected fluxes of lost energetic neutral beam ions during TF ripple experiments are presented as justification of this proposed solution.

  3. The Anomalous Currents In The Front Foils of the JET Lost Alpha Diagnostic KA-2

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, F. E.; Kiptily, V.; Salmi, A.; Horton, A.; Fullard, K.; Murari, A.; Darrow, D.; Hill, K.

    2011-05-04

    We have examined the observed currents in the front foils of the JET Faraday cup lost alpha particle diagnostic KA-2. In particular, we have sought to understand the currents during Ohmic plasmas for which the ion flux at the detectors was initially assumed to be negligible. We have considered two sources of this current: plasma ions both deuterium and impurity in the vicinity of the detector including charge exchange neutrals and photoemission from scattered UV radiation. Based upon modeling and empirical observation, the latter source appears most likely and, moreover, seems to be applicable to the currents in the front foil during ELMy H-mode plasmas. A very thin gold or nickel foil attached to the present detector aperture is proposed as a solution to this problem, and realistic calculations of expected fluxes of lost energetic neutral beam ions during TF ripple experiments are presented as justification of this proposed solution.

  4. Controlled Zn-mediated grafting of thin layers of bipodal diazonium salt on gold and carbon substrates.

    Science.gov (United States)

    Torréns, Mabel; Ortiz, Mayreli; Turner, Anthony P F; Beni, Valerio; O'Sullivan, Ciara K

    2015-01-07

    A controlled, rapid, and potentiostat-free method has been developed for grafting the diazonium salt (3,5-bis(4-diazophenoxy)benzoic acid tetrafluoroborate (DCOOH)) on gold and carbon substrates, based on a Zn-mediated chemical dediazonation. The highly stable thin layer organic platforms obtained were characterized by cyclic voltammetry, AFM, impedance, XP, and Raman spectroscopies. A dediazonation mechanism based on radical formation is proposed. Finally, DCOOH was proved as a linker to an aminated electroactive probe. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

    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.)

  6. Radioactivity analysis in niobium activation foils

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, G.E.

    1995-06-01

    The motivation for this study was to measure and analyze the activity of six (6) niobium (Nb) foils (the x-rays from an internal transition in Nb-93m) and apply this information with previously obtained activation foil data. The niobium data was used to determine the epithermal to MeV range for the neutron spectrum and fluence. The foil activation data was re-evaluated in a spectrum analysis code (STAY`SL) to provide new estimates of the exposure at the Los Alamos Spallation Radiation Effect Facility (LASREF). The activity of the niobium foils was measured and analyzed at the University of Missouri-Columbia (UMC) under the direction of Professor William Miller. The spectrum analysis was performed at the University of Missouri-Rolla (UMR) by Professor Gary Mueller.

  7. Nanodiamond Foils for H- Stripping to Support the Spallation Neutron Source (SNS) and Related Applications

    Energy Technology Data Exchange (ETDEWEB)

    Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL; Harris, Gary [Howard University; Piazza, Fabrice [Pontifica Universidad Catolica Madre y Maestra, Dominican Republic

    2013-01-01

    Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a single nanodiamond foil about the size of a postage stamp is critical to the entire operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control over film thickness. The results are discussed in the light of development

  8. A state enumeration of the foil knot

    OpenAIRE

    Ramaharo, Franck; Rakotondrajao, Fanja

    2017-01-01

    We split the crossings of the foil knot and enumerate the resulting states with a generating polynomial. Unexpectedly, the number of such states which consist of two components are given by the lazy caterer's sequence. This sequence describes the maximum number of planar regions that is obtained with a given number of straight lines. We then establish a bijection between this partition of the plane and the concerned foil splits sequence.

  9. Light Barrier for Non-Foil Packaging

    Science.gov (United States)

    2010-12-16

    foil and all-plastic materials were retorted and a second set of all-plastic packaged entrees were Microwave Sterilized on the Washington State...Copolymers for Retort Applications; SPE Polyolefins and Flexible Packaging Conference: Society of Plastics Engineers. Newtown. CT, 43pp. Thellen C...Final Scientific Report Light Barrier for Non-Foil Packaging Contract No. W911QY-08-C-0132 Final Scientific Report Contract No. W911QY-08-C-0132

  10. Screen printing as a scalable and low-cost approach for rigid and flexible thin-film transistors using separated carbon nanotubes.

    Science.gov (United States)

    Cao, Xuan; Chen, Haitian; Gu, Xiaofei; Liu, Bilu; Wang, Wenli; Cao, Yu; Wu, Fanqi; Zhou, Chongwu

    2014-12-23

    Semiconducting single-wall carbon nanotubes are very promising materials in printed electronics due to their excellent mechanical and electrical property, outstanding printability, and great potential for flexible electronics. Nonetheless, developing scalable and low-cost approaches for manufacturing fully printed high-performance single-wall carbon nanotube thin-film transistors remains a major challenge. Here we report that screen printing, which is a simple, scalable, and cost-effective technique, can be used to produce both rigid and flexible thin-film transistors using separated single-wall carbon nanotubes. Our fully printed top-gated nanotube thin-film transistors on rigid and flexible substrates exhibit decent performance, with mobility up to 7.67 cm2 V(-1) s(-1), on/off ratio of 10(4)∼10(5), minimal hysteresis, and low operation voltage (transistors (bent with radius of curvature down to 3 mm) and driving capability for organic light-emitting diode have been demonstrated. Given the high performance of the fully screen-printed single-wall carbon nanotube thin-film transistors, we believe screen printing stands as a low-cost, scalable, and reliable approach to manufacture high-performance nanotube thin-film transistors for application in display electronics. Moreover, this technique may be used to fabricate thin-film transistors based on other materials for large-area flexible macroelectronics, and low-cost display electronics.

  11. Stainless Steel Foil with Improved Creep-Resistance for Use in Primary Surface Recuperators for Gas Turbine Engines

    International Nuclear Information System (INIS)

    Browning, P.F.; Fitzpatrick, M.; Grubb, J.F.; Klug, R.C.; Maziasz, P.J.; Montague, J.P.; Painter, R.A.; Swindeman, R.W.

    1998-01-01

    Primary surface recuperators (PSRs) are compact heat-exchangers made from thin-foil type 347 austenitic stainless steel, which boost the efficiency of land-based gas turbine engines. Solar Turbines uses foil folded into a unique corrugated pattern to maximize the primary surface area for efficient heat transfer between hot exhaust gas on one side, and the compressor discharge air on the other side of the foil. Allegheny-Ludlum produces 0.003 - 0.0035 in. thick foil for a range of current turbine engines using PSRs that operate at up to 660 degrees C. Laboratory-scale processing modification experiments recently have demonstrated that dramatic improvements can be achieved in the creep resistance of such typical 347 stainless steel foils. The modified processing enables fine NbC carbide precipitates to develop during creep at 650-700 degrees C, which provides strength even with a fine grain size. Such improved creep-resistance is necessary for advanced turbine systems that will demand greater materials performance and reliability at higher operating conditions. The next challenges are to better understand the nature of the improved creep resistance in these 347 stainless steel foil, and to achieve similar improvements with scale-up to commercial foil production

  12. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Hristu, Radu; Stanciu, Stefan G.; Tranca, Denis E.; Stanciu, George A.

    2015-01-01

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed

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

    Science.gov (United States)

    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.

  14. Dry And Ringer Solution Lubricated Tribology Of Thin Osseoconductive Metal Oxides And Diamond-Like Carbon Films

    Directory of Open Access Journals (Sweden)

    Waldhauser W.

    2015-09-01

    Full Text Available Achieving fast and strong adhesion to jawbone is essential for dental implants. Thin deposited films may improve osseointegration, but they are prone to cohesive and adhesive fracture due to high stresses while screwing the implant into the bone, leading to bared, less osteoconductive substrate surfaces and nano- and micro-particles in the bone. Aim of this work is the investigation of the cohesion and adhesion failure stresses of osteoconductive tantalum, titanium, silicon, zirconium and aluminium oxide and diamond-like carbon films. The tribological behaviour under dry and lubricated conditions (Ringer solution reveals best results for diamond-like carbon, while cohesion and adhesion of zirconium oxide films is highest.

  15. X-ray emission, ablation pressure, and preheating for foils irradiated at 0. 26. mu. m wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

    1985-11-01

    The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 ..mu..m laser at intensities approx.10/sup 15/ W cm/sup -2/ are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 ..mu..m), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant.

  16. X-ray emission, ablation pressure, and preheating for foils irradiated at 0.26 μm wavelength

    International Nuclear Information System (INIS)

    Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

    1985-01-01

    The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 μm laser at intensities approx.10 15 W cm -2 are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 μm), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant

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

    Science.gov (United States)

    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.

  18. Tungsten foil laminate for structural divertor applications – Analyses and characterisation of tungsten foil

    International Nuclear Information System (INIS)

    Reiser, Jens; Rieth, Michael; Dafferner, Bernhard; Hoffmann, Andreas; Yi Xiaoou; Armstrong, David E.J.

    2012-01-01

    It has been attempted for several years to synthesise a tungsten material with a low brittle-to-ductile transition temperature and a high fracture toughness that can be used for structural parts. It was shown in our previous work that tungsten foil is ductile at room temperature and that this ductility can be transformed to bulk by synthesising a tungsten laminate. In this work we want to focus on tungsten foil and assess the microstructure as well as the mechanical properties of the foil. The assessment of the microstructure of 0.1 mm tungsten foil will be performed using electron microscopy. It will be shown that the grains of the tungsten foil have a dimension of 0.5 μm × 3 μm × 15 μm and a clear texture in (1 0 0) 〈0 1 1〉. This texture becomes even more pronounced by annealing. Three-point-bending tests with tungsten foil, as-received, will define the barriers: ductile at room temperature and brittle in liquid nitrogen (−196 °C). This shows that the ductility is a thermally activated process. Recrystallised tungsten foil (annealed for 1 h/2700 °C) shows ductile material behaviour at 200 °C. The paper closes with a discussion on the reasons of the ductility of 0.1 mm tungsten foil. These might be the ultra fine grained (UFG) microstructure or, in other words, a nano microstructure (see tungsten foil as-received), the high amount of mobile edge dislocations, and/or the foil effect, which means that dislocations can move to the surface and are annihilated (see tungsten foil recrystallised).

  19. Electrochemical studies of iron/carbonates system applied to the formation of thin layers of siderite on inert substrates

    International Nuclear Information System (INIS)

    Ithurbide, A.; Peulon, S.; Mandin, Ph.; Beaucaire, C.; Chausse, A.

    2007-01-01

    In order to understand the complex mechanisms of the reactions occurring, a methodology is developed. It is based on the use of compounds electrodeposited under the form of thin layers and which are used then as electrodes to study their interactions with the toxic species. It is in this framework that is studied the electrodeposition of siderite on inert substrates. At first, have been studied iron electrochemical systems in carbonated solutions. These studies have been carried out with classical electrochemical methods (cyclic voltametry, amperometry) coupled to in-situ measurements: quartz microbalance, pH. Different compounds have been obtained under the form of homogeneous and adherent thin layers. The analyses of these depositions, by different ex-situ characterizations (XRD, IR, SEM, EDS..) have revealed particularly the presence of siderite. Then, the influence of several experimental parameters (substrate, potential, medium composition, temperature) on the characteristics of siderite thin layers has been studied. From these experimental results, models have been proposed. (O.M.)

  20. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Science.gov (United States)

    Li, Pengfei; Xue, Wei

    2010-06-01

    Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs) with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current-voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  1. Study of optical properties of vacuum evaporated carbon nanotube containing Se80Te16Cu4 thin films

    Science.gov (United States)

    Upadhyay, A. N.; Tiwari, R. S.; Singh, Kedar

    2016-08-01

    Thin films of Se80Te16Cu4 glassy alloy and 3 wt.% of carbon nanotubes (CNTs) containing Se80Te16Cu4 glassy composite were deposited on clean glass substrate by thermal evaporation technique. The scanning electron microscope and energy dispersive x-ray analysis were performed to investigate the surface morphology and elemental composition of as synthesised samples. The reflectance and transmittance spectra of as-deposited thin films were recorded (200-1100 nm) by using UV/VIS/NIR spectrophotometer. The optical band gap and optical constants such as absorption coefficient (α), refractive index (n) and extinction coefficient (k) of Se80Te16Cu4 and 3 wt.% CNTs-Se80Te16Cu4 glassy composite thin films were calculated. It is observed that optical properties alter due to CNTs incorporation in Se80Te16Cu4 glassy alloy. Effect on optical properties due to CNTs incorporation can be explained in terms of concentration of unsaturated bonds/defects in the localised states.

  2. Development of Wall Thinning Distinction Method using the Multi-inspecting UT Data of Carbon Steel Piping

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyeong Mo; Yun, Hun; Lee, Chan Kyoo [KEPCO E and C, Yongin (Korea, Republic of)

    2012-05-15

    To manage the wall thinning of carbon steel piping in nuclear power plants, the utility of Korea has performed thickness inspection for some quantity of pipe components during refueling outages and determined whether repair or replacement after evaluating UT (Ultrasonic Test) data. When the existing UT data evaluation methods, such as Band, Blanket, PTP (Point to Point) Methods, are applied to a certain pipe component, unnecessary re-inspecting situations may be generated even though the component does not thinned. In those cases, economical loss caused by repeated inspection and problems of maintaining the pipe integrity followed by decreasing of newly inspected components may be generated. EPRI (Electric Power Research Institute) in USA has suggested several statistical methods, TPM (Total Point Method), LSS (Least Square Slope) Method, etc. to distinguish whether multiple inspecting components have thinned or not. This paper presents the analysis results for multiple inspecting components over three times based on both NAM (Near Area of Minimum) Method developed by KEPCO-E and C and the other methods suggested by EPRI.

  3. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Directory of Open Access Journals (Sweden)

    Li Pengfei

    2010-01-01

    Full Text Available Abstract Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current–voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  4. Tuning thin-film electrolyte for lithium battery by grafting cyclic carbonate and combed poly(ethylene oxide) on polysiloxane.

    Science.gov (United States)

    Li, Jie; Lin, Yue; Yao, Hehua; Yuan, Changfu; Liu, Jin

    2014-07-01

    A tunable polysiloxane thin-film electrolyte for all-solid-state lithium-ion batteries was developed. The polysiloxane was synthesized by hydrosilylation of polymethylhydrosiloxane with cyclic [(allyloxy)methyl]ethylene ester carbonic acid and vinyl tris(2-methoxyethoxy)silane. (1) H NMR spectroscopy and gel-permeation chromatography demonstrated that the bifunctional groups of the cyclic propylene carbonate (PC) and combed poly(ethylene oxide) (PEO) were well grafted on the polysiloxane. At PC/PEO=6:4, the polysiloxane-based electrolyte had an ionic conductivity of 1.55 × 10(-4) and 1.50 × 10(-3)  S cm(-1) at 25 and 100 °C, respectively. The LiFePO4 /Li batteries fabricated with the thin-film electrolyte presented excellent cycling performance in the temperature range from 25 to 100 °C with an initial discharge capacity at a rate of 1 C of 88.2 and 140 mA h g(-1) at 25 and 100 °C, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Morphology and Precipitation Kinetics of MnS in Low-Carbon Steel During Thin Slab Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    YU Hao; KANG Yong-lin; ZHAO Zheng-zhi; SUN Hao

    2006-01-01

    The morphology of manganese sulfide formed during thin slab continuous casting process in low-carbon steel produced by compact strip production (CSP) technique was investigated. Using transmission electron microscopy analysis, it was seen that a majority of manganese sulfides precipitated at austenite grain boundaries, the morphologies of which were spherical or close to the spherical shape and the size of MnS precipitates ranged from 30 nm to 100 nm. A mathematical model of the manganese sulfide precipitation in this process was developed based on classical nucleation theory. Under the given conditions, the starting and finishing precipitation temperatures of MnS in the continuous casting thin slab of the studied low-carbon steel are 1 189 ℃ and 1 171 ℃, respectively, and the average diameter of MnS precipitates is about 48 nm within this precipitation temperature range. The influences of chemical components and thermo-mechanical processing conditions on the precipitation behavior of MnS in the same process were also discussed.

  6. Fabrication of air-stable n-type carbon nanotube thin-film transistors on flexible substrates using bilayer dielectrics.

    Science.gov (United States)

    Li, Guanhong; Li, Qunqing; Jin, Yuanhao; Zhao, Yudan; Xiao, Xiaoyang; Jiang, Kaili; Wang, Jiaping; Fan, Shoushan

    2015-11-14

    Single-walled carbon nanotube (SWNT) thin-film transistors hold great potential for flexible electronics. However, fabrication of air-stable n-type devices by methods compatible with standard photolithography on flexible substrates is challenging. Here, we demonstrated that by using a bilayer dielectric structure of MgO and atomic layer deposited (ALD) Al2O3 or HfO2, air-stable n-type devices can be obtained. The mechanism for conduction type conversion was elucidated and attributed to the hole depletion in SWNT, the decrease of the trap state density by MgO assimilating adsorbed water molecules in the vicinity of SWNT, and the energy band bending because of the positive fixed charges in the ALD layer. The key advantage of the method is the relatively low temperature (120 or 90 °C) required here for the ALD process because we need not employ this step to totally remove the absorbates on the SWNTs. This advantage facilitates the integration of both p-type and n-type transistors through a simple lift off process and compact CMOS inverters were demonstrated. We also demonstrated that the doping of SWNTs in the channel plays a more important role than the Schottky barriers at the metal contacts in carbon nanotube thin-film transistors, unlike the situation in individual SWNT-based transistors.

  7. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers

    International Nuclear Information System (INIS)

    Costa e Silva, Danilo Lopes

    2015-01-01

    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  8. Study of secondary electron emission from thin carbon targets with swift charged particles: heavy ions, hydrogen ions; Etude experimentale de l`emission electronique secondaire de cibles minces de carbone sous l`impact de projectiles rapides: ions lourds, ions hydrogene (atomiques, moleculaires ou sous forme d`agregats)

    Energy Technology Data Exchange (ETDEWEB)

    Billebaud, A

    1995-07-12

    The main subject of this work is the study of electron emission from the two surfaces of thin solid targets bombarded with swift charged particles. The slowing down of swift ions in matter is mainly due to inelastic interaction with target electrons (ionization, excitation): the energy transfer to target electrons is responsible for the secondary electron emission process. The phenomenological and theoretical descriptions of this phenomena are the subject of the first chapter. We focused on secondary electron emission induced by different kind of projectiles on thin carbon foils. In chapter two we describe hydrogen cluster induced electron emission measurement between 40 and 120 keV/proton. These projectiles, composed of several atoms, allowed us to study and highlight collective effects of the electron emission process. We extended our study of electron emission to molecular (H{sub 2}{sup +}, H{sub 3}{sup +}) and composite (H{sup -}, H{sup 0}) projectiles at higher energies (<= 2 MeV): we have designed an experimental set-up devoted to electron emission statistics measurements which allowed us to study, among others things, the role of projectile electrons in secondary electron emission. This experiment is described in the third chapter. Finally, the fourth chapter describes new measurements of electron emission induced by energetic (13 MeV/u) and highly charged argon ion provided by the medium energy beam line (SME) of GANIL (Caen), which have been analyzed in the framework of a semi-empirical model of secondary electron emission. This set of experiments brings new results on composite projectile interaction with matter, and on the consequences of high energy deposition in solids. (author).

  9. The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Wardaya, P. D., E-mail: pongga.wardaya@utp.edu.my; Noh, K. A. B. M., E-mail: pongga.wardaya@utp.edu.my; Yusoff, W. I. B. W., E-mail: pongga.wardaya@utp.edu.my [Petroleum Geosciences Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Ridha, S. [Petroleum Engineering Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Nurhandoko, B. E. B. [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Dept. of Physics, Institute of Technology Bandung, Bandung, Indonesia and Rock Fluid Imaging Lab, Bandung (Indonesia)

    2014-09-25

    This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic

  10. The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

    International Nuclear Information System (INIS)

    Wardaya, P. D.; Noh, K. A. B. M.; Yusoff, W. I. B. W.; Ridha, S.; Nurhandoko, B. E. B.

    2014-01-01

    This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave

  11. Processing behaviors of thin-film pentacene and benzene-1,4-diboronic acid in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Ngo, Truc T.; Keegan, James E.; George, Robert D.

    2011-01-01

    This research investigates the feasibility of using supercritical carbon dioxide (scCO 2 ) as a green solvent for processing organic thin film semiconductor, such as pentacene, and a potential molecular modifier for use in electronic device applications. Benzene-1,4-diboronic acid (BDBA) was selected as a molecular modifier in this work due to its electron deficient nature, which can potentially enhance pentacene's physical, chemical or electronic properties by changing its structure in the solid state. In this study, the solubilities of BDBA and pentacene in scCO 2 are measured as individual compounds and as co-solutes, at 313 K, using ultraviolet (UV) spectroscopy. Methanol co-solvent effects on solubility have also been characterized for each compound. The results show that BDBA is insoluble in pure scCO 2 up to 1.82 × 10 7 Pa. However, with a small amount of methanol added to the mixture, BDBA becomes soluble in solution with a solubility of 3.81 × 10 −4 mol/l at 9.00 × 10 6 -Pa-pressure. In contrast, pentacene is only soluble in scCO 2 at pressures above 1.10 × 10 7 Pa, and its solubility is decreased upon addition of methanol due to the non-polar nature of pentacene. When a pentacene thin film is treated with BDBA in scCO 2 /methanol solution, BDBA sorption is observed at pressures as low as 8.80 × 10 6 Pa. Based on these results, it is concluded that treatment of pentacene thin films in scCO 2 is a promising approach that can be optimized for BDBA and other similar molecular modifiers, to produce multi-component organic thin film devices.

  12. System requirements for the Los Alamos foil-implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Bowers, R.; Greene, A.; Lindemuth, I.; Nickel, G.; Oliphant, T.; Weiss, D.

    1983-01-01

    The goal of the Los Alamos imploding foil project is the development of an intense source of soft x rays and hot plasma produced from the thermalization of 1 to 10 MJ of plasma kinetic energy. The source will be used for material studies and fusion experiments. Specifically, thin, current-carrying cylindrical metallic plasmas are imploded via their self-magnetic forces. Features of this project are the use of high-explosive-driven flux-compression generators as the prime power source to achieve very high energies and fast opening switches to shorten the electrical pulses. To reach a load kinetic energy of 10 MJ, it is expected that the foil-plasma must carry about 50 MA of current and must implode in less than 1/2 μsec. This imposes the requirements that switch opening times must be less than 1/2 μsec and the transmission line must withstand voltages of about 1 MV. The system being pursued at Los Alamos is described, and model calculations are presented

  13. A simple method for the measurement of reflective foil emissivity

    International Nuclear Information System (INIS)

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

    2013-01-01

    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

  14. A simple method for the measurement of reflective foil emissivity

    Science.gov (United States)

    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.

  15. Cryostat with Foil and MLI

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Peter K.F.; Gung, Chen-yu

    2005-10-06

    Induction cores are used to accelerate heavy ion beam array, which are built around the outer diameter of the cryostat housing the superconducting quadruple array. Compact cryostat is highly desirable to reduce the cost of the induction cores. Recent experiences in fabrication of a cryostat for single beam transport revealed that it is possible to reduce the spacing in the cryostat vacuum jacket by using low-emissivity thermal insulation material instead of conventional MLI. However, it is labor-intensive to install the new type of insulation as compared with using MLI. It is promising to build a cost-effective compact cryostat for quadruple magnet array for heavy ion beam array transport by using low-emissivity material combined with conventional MLI as radiation insulation. A matrix of insulation designs and tests will be performed as the feasibility study and for the selection of the optimal thermal insulation as the Phase I work. The selected mixed insulation will be used to build prototype compact cryostats in the Phase II project, which are aiming for housing quadruple doublet array. In this STTR phase I study, a small cryostat has been designed and built to perform calorimetric characterization of the heat load in a liquid helium vessel insulated with a vacuum layer with a nominal clearance of 3.5 mm. The vacuum clearance resembled that used in the warm-bore beam tube region in a prototype cryostat previously built for the heavy ion beam transport experiment. The vacuum clearance was geometrically restricted with a heater shell with the temperature controlled at near 300 K. Various combinations of radiation and thermal shields were installed in the tight vacuum clearance for heat load measurements. The measured heat loads are reported and compared with previous test result using a compact vacuum layer. Further developments of the thermal insulations used in the present study are discussed. The compact cryostat with foil and MLI insulation may be used in the

  16. Thin polyaniline and polyaniline/carbon nanocomposite films for gas sensing

    Czech Academy of Sciences Publication Activity Database

    Lobotka, P.; Kunzo, P.; Kováčová, E.; Vávra, I.; Križanová, O.; Smatko, V.; Stejskal, Jaroslav; Konyushenko, Elena; Omastová, M.; Špitálský, Z.; Mičušík, M.; Krupa, I.

    2011-01-01

    Roč. 519, č. 12 (2011), s. 4123-4127 ISSN 0040-6090 Institutional research plan: CEZ:AV0Z40500505 Keywords : gas sensor * polyaniline thin film * nanocomposite Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.890, year: 2011

  17. Synthesis of Ag-doped hydrogenated carbon thin films by a hybrid ...

    Indian Academy of Sciences (India)

    Sci., Vol. 37, No. 7, December 2014, pp. 1669–1676. c Indian Academy of Sciences. Synthesis of ... PVD–PECVD deposition process ... Processing parameters (working pressure, .... prepared using the hydrocarbon ion beam without oper- .... Figure 5. Comparison of FTIR spectra obtained from the DLC and Ag-DLC thin.

  18. An investigation into which factors control the nanotribological behaviour of thin sputtered carbon films

    International Nuclear Information System (INIS)

    Shi Baogui; Sullivan, John L; Beake, Ben D

    2008-01-01

    Ultra-thin (20-100 nm) films deposited on Si surfaces can improve their mechanical and tribological properties. As a stepping stone towards the optimization of such ultra-thin films, herein we report experimental nanoscratch and nanowear data on a-C films of thickness in the range 200-1000 nm on Si aiming to (1) understand the role of film thickness on the nanoscratch behaviour, (2) determine whether the same factors (substrate bias, H/E ratio, etc) are at play for thick films as for the thin films, (3) determine possible design rules for thinner films enabling their optimization for MEMS applications and (4) evaluate the use of the multi-pass (3-scan) procedure for clarifying the locus of failure. To a first approximation, the critical load for total film failure in the nanoscratch test is proportional to thickness provided the films are not too stressed. a-C films of 1 μm with very high H/E, deposited under high substrate bias, perform well at low load but very poorly in more highly loaded situations. Not only do they exhibit low critical loads but also failure involves extensive delamination outside of the scratch track. This is not observed on thinner films. A suitable strategy for optimizing wear resistance for thin films for MEMS applications is to aim to maximize H/E. For the 200 nm films studied here, the films with the highest H/E showed slightly improved scratch resistance

  19. Thin-film transistors and circuits on plastic foil

    NARCIS (Netherlands)

    Heremans, P.; Genoe, J.; Steudel, S.; Myny, K.; Smout, S.; Vicca, P.; Grillberger, C.; Hild, O.R.; Furthner, F.; Putten, B. van der; Tripathi, A.K.; Gelinck, G.H.

    2009-01-01

    We present our recent achievements in organic semiconductor technology in two emerging application areas. We show that the performance of our technology approaches the requirements for Electronic Product Coding RFID tags. Also, backplanes of OLED displays are enabled by the unique compatibility of

  20. Coupling of carbon monoxide molecules over oxygen-defected UO2(111) single crystal and thin film surfaces.

    Science.gov (United States)

    Senanayake, S D; Waterhouse, G I N; Idriss, H; Madey, Theodore E

    2005-11-22

    While coupling reactions of carbon-containing compounds are numerous in organometallic chemistry, they are very rare on well-defined solid surfaces. In this work we show that the reductive coupling of two molecules of carbon monoxide to C2 compounds (acetylene and ethylene) could be achieved on oxygen-defected UO2(111) single crystal and thin film surfaces. This result allows in situ electron spectroscopic investigation of a typical organometallic reaction such as carbon coupling and extends it to heterogeneous catalysis and solids. By using high-resolution photoelectron spectroscopy (HRXPS) it was possible to track the changes in surface states of the U and O atoms as well as identify the intermediate of the reaction. Upon CO adsorption U cations in low oxidation states are oxidized to U4+ ions; this was accompanied by an increase of the O-to-U surface ratios. The HRXPS C 1s lines show the presence of adsorbed species assigned to diolate species (-OCH=CHO-) that are most likely the reaction intermediate in the coupling of two CO molecules to acetylene and ethylene.

  1. Coupling of Carbon Monoxide Molecules over Oxygen Defected UO2 (111) Single Crystal and Thin Film Surfaces

    International Nuclear Information System (INIS)

    Senanayake, S.; Waterhouse, G.; Idriss, H.; Madey, T.

    2005-01-01

    While coupling reactions of carbon-containing compounds are numerous in organometallic chemistry, they are very rare on well-defined solid surfaces. In this work we show that the reductive coupling of two molecules of carbon monoxide to C 2 compounds (acetylene and ethylene) could be achieved on oxygen-defected UO 2 (111) single crystal and thin film surfaces. This result allows in situ electron spectroscopic investigation of a typical organometallic reaction such as carbon coupling and extends it to heterogeneous catalysis and solids. By using high-resolution photoelectron spectroscopy (HRXPS) it was possible to track the changes in surface states of the U and O atoms as well as identify the intermediate of the reaction. Upon CO adsorption U cations in low oxidation states are oxidized to U 4+ ions; this was accompanied by an increase of the O-to-U surface ratios. The HRXPS C 1s lines show the presence of adsorbed species assigned to diolate species (-OCH=CHO-) that are most likely the reaction intermediate in the coupling of two CO molecules to acetylene and ethylene

  2. Opto-electrical properties of amorphous carbon thin film deposited from natural precursor camphor

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Debabrata [Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076 (India)]. E-mail: dpradhan@sciborg.uwaterloo.ca; Sharon, Maheshwar [Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076 (India)

    2007-06-30

    A simple thermal chemical vapor deposition technique is employed for the pyrolysis of a natural precursor 'camphor' and deposition of carbon films on alumina substrate at higher temperatures (600-900 deg. C). X-ray diffraction measurement reveals the amorphous structure of these films. The carbon films properties are found to significantly vary with the deposition temperatures. At higher deposition temperature, films have shown predominately sp{sup 2}-bonded carbon and therefore, higher conductivity and lower optical band gap (Tauc gap). These amorphous carbon (a-C) films are also characterized with Raman and X-ray photoelectron spectroscopy. In addition, electrical and optical properties are measured. The thermoelectric measurement shows these as-grown a-C films are p-type in nature.

  3. Applications of beam-foil spectroscopy to atomic collisions in solids

    Science.gov (United States)

    Sellin, I. A.

    1976-01-01

    Some selected papers presented at the Fourth International Conference on Beam-Foil Spectroscopy, whose results are of particular pertinence to ionic collision phenomena in solids, are reviewed. The topics discussed include solid target effects and means of surmounting them in the measurement of excited projectile ion lifetimes for low-energy heavy element ions; the electron emission accompanying the passage of heavy particles through solid targets; the collision broadening of X rays emitted from 100 keV ions moving in solids; residual K-shell excitation in chlorine ions penetrating carbon; comparison between 40 MeV Si on gaseous SiH4 targets at 300 mtorr and 40 MeV Si on Al; and the emergent surface interaction in beam-foil spectroscopy. A distinct overlap of interests between the sciences of beam-foil spectroscopy and atomic collisions in solids is pointed out.

  4. Responses of forest carbon and water coupling to thinning treatments at both the leaf and individual tree levels in a 16-year-old natural Pinus Contorta stand

    Science.gov (United States)

    Wang, Y.; Wei, A.; del Campo, A.; Li, Q.; Giles-Hansen, K.

    2017-12-01

    Large-scale disturbances in Canadian forests, including mountain pine beetle infestation in western Canada, forest fires, timber harvesting and climate change impacts, have significantly affected both forest carbon and water cycles. Thinning, which selectively removes trees at a given forest stand, may be an effective tool to mitigate the effect of these disturbances. Various studies have been conducted to assess the thinning effect on growth, transpiration, and nutrient availability; however, relatively few studies have been conducted to examine its effect on the coupling of forest carbon and water. Thus, the objective of this research is to evaluate the effect of thinning on forest carbon and water coupling at both the leaf and tree levels in a 16-year-old natural Pinus Contorta forest in the interior of British Columbia in Canada. We used water-use efficiency (WUE), the ratio of basal area increment (BA) to tree transpiration (E), as the indicator of the carbon and water coupling at individual tree level, and use intrinsic water-use efficiency (iWUE), the ratio of photosynthesis (A) to stomatal conductance (G), to represent the coupling at the leaf level. Field experiments were conducted in the Upper Penticton Watershed where the mean annual precipitation is 750 mm with seasonal drought during summer. A randomized block design was used, with three blocks each containing two thinning intensities and one unthinned plot (T1: 4,500, T2: 1,100, C: 26,400 trees per ha.). From May to October 2016, basal diameter, sap flow, and environmental conditions were monitored continuously at every 20 minutes, while A and G were measured weekly. Preliminary results showed that thinning significantly increased solar radiation, wind speed, and soil moisture in the treatment plots, where the changes observed were proportional to the intensity of the thinning; but thinning did not change stand level temperature and relative humidity. Thinning also significantly enhanced tree E and BA

  5. Composite Design for a Foiling Optimist Dinghy

    Directory of Open Access Journals (Sweden)

    Carolyn Oddy

    2018-02-01

    Full Text Available In April 2017, a foiling Optimist dingy designed entirely by students, was successfully tested under standard sailing conditions in the waters outside Gothenburg. In order to achieve take of wind speeds as low as 6 m/s, a stiff and lightweight design of the dinghy and its foiling components was necessary. There have been few successful attempts to make an Optimist foil in a stable manner, as such there were no standards or recommendations available for the design. Therefore, a simulation driven structural design methodology for hydrofoils, centreboards, centreboard-to-hull connections, and necessary hull reinforcements using sandwich structures was adopted. The proposed design was then manufactured, allowing for a significantly stiffer hull and a 20% decrease in weight over a conventional Optimist. Excluding the rig and sail, the final weight came to 27 kg.

  6. Temperature Dependence on Structural, Tribological, and Electrical Properties of Sputtered Conductive Carbon Thin Films

    International Nuclear Information System (INIS)

    Park, Yong Seob; Hong, Byung You; Cho, Sang Jin; Boo, Jin Hyo

    2011-01-01

    Conductive carbon films were prepared at room temperature by unbalanced magnetron sputtering (UBMS) on silicon substrates using argon (Ar) gas, and the effects of post-annealing temperature on the structural, tribological, and electrical properties of carbon films were investigated. Films were annealed at temperatures ranging from 400 .deg. C to 700 .deg. C in increments of 100 .deg. C using a rapid thermal annealing method by vacuum furnace in vacuum ambient. The increase of annealing temperature contributed to the increase of the ordering and formation of aromatic rings in the carbon film. Consequently, with increasing annealing temperature the tribological properties of sputtered carbon films are deteriorated while the resistivity of carbon films significantly decreased from 4.5 x 10 -3 to 1.0 x 10 -6 Ω-cm and carrier concentration as well as mobility increased, respectively. This behavior can be explained by the increase of sp 2 bonding fraction and ordering sp 2 clusters in the carbon networks caused by increasing annealing temperature

  7. Uranium Anodic Dissolution under Slightly Alkaline Conditions Progress Report Full-Scale Demonstration with DU Foil

    Energy Technology Data Exchange (ETDEWEB)

    Gelis, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Brown, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Wiedmeyer, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, G. F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-02-18

    Argonne National Laboratory (Argonne) is developing an alternative method for digesting irradiated low enriched uranium (LEU) foil targets to produce 99Mo in neutral/alkaline media. This method consists of the electrolytic dissolution of irradiated uranium foil in sodium bicarbonate solution, followed by precipitation of base-insoluble fission and activation products, and uranyl-carbonate species with CaO. The addition of CaO is vital for the effective anion exchange separation of 99MoO42- from the fission products, since most of the interfering anions (e.g., CO32-) are removed from the solution, while molybdate remains in solution. An anion exchange is used to retain and to purify the 99Mo from the filtrate. The electrochemical dissolver has been designed and fabricated in 304 stainless-steel (SS), and tested for the dissolution of a full-size depleted uranium (DU) target, wrapped in Al foil. Future work will include testing with low-burn-up DU foil at Argonne and later with high-burn-up LEU foils at Oak Ridge National Laboratory.

  8. Surface structure deduced differences of copper foil and film for graphene CVD growth

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Junjun [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Hu, Baoshan, E-mail: hubaoshan@cqu.edu.cn [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Wei, Zidong; Jin, Yan [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Luo, Zhengtang [Department of Chemical and Biomolecular Engineering, The Hongkong University of Science and Technology, Kowloon (Hong Kong); Xia, Meirong [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Pan, Qingjiang [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, Heilongjiang University, Harbin 150080 (China); Liu, Yunling [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China)

    2014-05-01

    Highlights: • We demonstrate the significant differences between Cu foil and film in the surface morphology and crystal orientation distribution. • The different surface structure leads to the distinctive influences of the CH₄ and H₂ concentrations on the thickness and quality of as-grown graphene. • Nucleation densities and growth rate differences at the initial growth stages on the Cu foil and film were investigated and discussed. Abstract: Graphene was synthesized on Cu foil and film by atmospheric pressure chemical vapor deposition (CVD) with CH₄ as carbon source. Electron backscattered scattering diffraction (EBSD) characterization demonstrates that the Cu foil surface after the H₂-assisted pre-annealing was almost composed of Cu(1 0 0) crystal facet with larger grain size of ~100 μm; meanwhile, the Cu film surface involved a variety of crystal facets of Cu(1 1 1), Cu(1 0 0), and Cu(1 1 0), with the relatively small grain size of ~10 μm. The different surface structure led to the distinctive influences of the CH₄ and H₂ concentrations on the thickness and quality of as-grown graphene. Further data demonstrate that the Cu foil enabled more nucleation densities and faster growth rates at the initial growth stages than the Cu film. Our results are beneficial for understanding the relationship between the metal surface structure and graphene CVD growth.

  9. Fuel cells based on the use of Pd foils

    Energy Technology Data Exchange (ETDEWEB)

    Cabot, P. L.; Guezala, E. [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Barcelona (Spain); Casado, J. [Departamento de Investigacion, Carburos Metalicos, Barcelona (Spain)

    1999-10-01

    Fuel cells with hydrogen diffusion lead anodes are of particular interest because the ability of lead to filter hydrogen with 100 per cent selectively, thus making it possible to take impure hydrogen from industrial flue gases and use it as feedstock to produce clean energy. In this investigation an alkaline fuel cell with a Pd-based hydrogen diffusion anode combined with a carbon-PFTE oxygen diffusion cathode was built up and tested at low temperatures. The fuel cell was operated by feeding pure hydrogen and pure oxygen at atmospheric pressures and closing the circuit by means of different external loads. Quasi-stationary currents were obtained for each load when the Pd foils were assembled using elastic joints to allow the anode creasing. Experiments with different sections indicated that the anode was the limiting electrode. Results showed that the slowest reactions in the overall anodic process depend on the anode preparation. When Pd black was present only at the Pd/electrolyte interface, the slowest reaction occurred on the gas/Pd interface. For anodes with Pd black on both sides of the foil, the maximum anode power densities were 11 and 18 mW cm{sup 2} at 25 and 50 degrees C, respectively; the corresponding anode current densities were 30 and 65 mA cm{sup 2}. Significant improvements in the anode current and power densities were achieved via surface modification by cathodically charging Pd pieces with atomic hydrogen, and Pd foils with electrodeposited Pd+Pt blacks, obtaining roughly double the power and current density. 31 refs., 9 figs.

  10. Thrust augmentation in tandem flapping foils by foil-wake interaction

    Science.gov (United States)

    Anderson, Erik; Lauder, George

    2006-11-01

    Propulsion by pitching and heaving airfoils and hydrofoils has been a focus of much research in the field of biologically inspired propulsion. Organisms that use this sort of propulsion are self-propelled, so it is difficult to use standard experimental metrics such as thrust and drag to characterize performance. We have constructed a flapping foil robot mounted in a flume on air-bearings that allows for the determination of self-propelled speed as a metric of performance. We have used a pair of these robots to examine the impact of an upstream flapping foil on a downstream flapping foil as might apply to tandem fins of a swimming organism or in-line swimming of schooling organisms. Self-propelled speed and a force transducer confirmed significant thrust augmentation for particular foil-to-foil spacings, phase differences, and flapping frequencies. Flow visualization shows the mechanism to be related to the effective angle of attack of the downstream foil due to the structure of the wake of the upstream foil. This confirms recent computational work and the hypotheses by early investigators of fish fluid dynamics.

  11. Spectra from foil-excited molybdenum ions

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Cecchi, J.L.; Kruse, T.H.

    1978-01-01

    The extreme-ultraviolet spectra (5 to 55 nm) for foil-excited molybdenum ions have been measured using 22 to 200 MeV beams from the Brookhaven National Laboratory MP tandem Van de Graaff accelerator facility, 20 μg/cm 2 C stripping foils, and a grazing incidence spectrometer. The mean ion charge states (13 to 28) and the narrow distribution widths (about 2 charge states) were accurately predictable from experimental parameters. Where possible, comparisons are given with Mo radiation from tokamaks, vacuum sparks, and laser-excited plasmas

  12. Calculation of electron transmission through aluminium foil

    International Nuclear Information System (INIS)

    Abroyan, M.A.; Mel'ker, A.I.; Mikhajlin, A.I.; Sirotinkin, V.V.; Tokmakov, I.L.

    1987-01-01

    Calculated by Monte Carlo method energy and angular distributions of electrons transmitted through aluminium foil with 50 μm thickness are presented. 200-500 electron energy ranges and angles of electron incidence on foil from 0 to 40 deg C are considered. That allows to use results for more universal accelerator group, for example, for accelerators with scanning beam used in industry. The received values of angular and energy characteristics allow to increase essentially estimation accuracy of accelerator extraction devices and dose distribution on irradiating item

  13. Compressor ported shroud for foil bearing cooling

    Science.gov (United States)

    Elpern, David G [Los Angeles, CA; McCabe, Niall [Torrance, CA; Gee, Mark [South Pasadena, CA

    2011-08-02

    A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

  14. Measurement of the activity coefficient of carbon in steels in liquid sodium

    International Nuclear Information System (INIS)

    Surville, G.

    1983-06-01

    In sodium cooled fast reactors carbon is both a carbon impurity and element of structural materials. Carbon transfert through liquid sodium can produce carburization or decarburization of structural materials. Carbon content in sodium is determined with thin foils of austenitic alloys, when equilibrium is reached thermodynamic activity of carbon in sodium is deduced from carbon activity in alloys. Studied alloys are FeMn 20%, FeNi 30%, Z2CN 18-10 and Z3CND17-13. Carbon activity of alloys in sodium was between 5.10 -3 and 10 -1 at 600 and 650 0 C. Calibration was obtained with the alloys FeNi 30% in gaseous mixtures He-CO-CO 2 of known activity [fr

  15. Effects of differently hardened brass foil laminate on the electromechanical property of externally laminated CC tapes

    Energy Technology Data Exchange (ETDEWEB)

    Bautista, Zhierwinjay; Shin, Hyung Seop [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of); Mean, Byoung Jean; Lee, Jae Hun [SuNAM Co Ltd., Anseong (Korea, Republic of)

    2016-12-15

    The mechanical properties of REBCO coated conductor (CC) wires under uniaxial tension are largely determined by the thick component layers in the architecture, namely, the substrate and the stabilizer or even the reinforcement layer. Depending on device applications of the CC tapes, it is necessary to reinforce thin metallic foils externally to one-side or both sides of the CC tapes. Due to the external reinforcement of brass foils, it was found that this could increase the reversible strain limit from the Cu-stabilized CC tapes. In this study, the effects of differently hardened brass foil laminate on the electromechanical property of CC tapes were investigated under uniaxial tension loading. The tensile strain dependence of the critical current (I{sub c}) was measured at 77 K and self-field. Depending on whether the I{sub c} of CC tapes were measured during loading or after unloading, a reversible strain (or stress) limit could be determined, respectively. The both-sides of the Cu-stabilized CC tapes were laminated with brass foils with different hardness, namely 1/4H, 1H and EH. From the obtained results, it showed that the yield strength of the brass laminated CC tapes with EH brass foil laminate was comparable to the one of the Cu-stabilized CC tape due to its large yield strength even though its large volume fraction. It was found that the brass foil with different hardness was mainly sensitive on the stress dependence of I{sub c}, but not on the strain sensitivity due to the residual strain induced in the laminated CC tapes during unloading.

  16. Application of a commercial diffusion type carbon meter in a sodium circuit

    International Nuclear Information System (INIS)

    Bhat, N.P.; Borgstedt, H.U.; Peric, Z.; Witting, G.

    1980-01-01

    The exchange of carbon between structural materials and liquid sodium influences the mechanical properties of components of the cooling circuits. Therefore, the estimation of the carbon content of the alkali metal and the knowledge of its carburizing potential is of importance. Since some years the measurement of the carburizing potential of sodium is easy to perform by the application of the foil equilibration method which leads to good results in spite of the very low carbon concentrations in the liquid metal. Thin foils (0.025 to 0.125 mm) of Fe-18Cr-8Ni-C alloy (corresponding to stainless steel type AISI 304) are immersed in sodium at 550 to 700 deg. C for 200 to 400 hours. The equilibrium of the carbon distribution must be reached. Chemical analyses of the steel tabs and relation of concentration to activity of carbon lead to information on the carbon concentration in the sodium, if the saturation concentration of carbon in sodium is known. The method gives arbitrary values over a longer period of time. The time needed for equilibration and analysis causes a delay for the getting of results. Therefore, there is a need for instruments which are capable to measure carbon directly in the circuits and give continuously information on the actual carbon activities in the fluid. Until 1975 only one carbon meter was commercially available. One unit in was tested a chemical analytical sodium circuit

  17. Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Khun, N.W. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Liu, E., E-mail: MEJLiu@ntu.edu.s [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2009-07-01

    Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 {sup o}C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp{sup 3}-bonded cross-link structure that was significantly affected by the substrate temperature.

  18. Effect of sputtering power on structure, adhesion strength and corrosion resistance of nitrogen doped diamond-like carbon thin films.

    Science.gov (United States)

    Khun, N W; Liu, E

    2011-06-01

    Nitrogen doped diamond-like carbon (DLC:N) thin films were deposited on highly conductive p-Si substrates using a DC magnetron sputtering deposition system. The DLC:N films were characterized using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM), contact angle measurement and micro-scratch test. The XPS and Raman results indicated that the sputtering power significantly influenced the properties of the films in terms of bonding configuration in the films. The corrosion performance of the DLC:N films was investigated in a 0.6 M NaCl solution by means of potentiodynamic polarization testing. It was found that the corrosion performance of the films could be enhanced by higher sputtering powers.

  19. Corrosion behavior of aluminum doped diamond-like carbon thin films in NaCl aqueous solution.

    Science.gov (United States)

    Khun, N W; Liu, E

    2010-07-01

    Aluminum doped diamond-like carbon (DLC:Al) thin films were deposited on n-Si(100) substrates by co-sputtering a graphite target under a fixed DC power (650 W) and an aluminum target under varying DC power (10-90 W) at room temperature. The structure, adhesion strength and surface morphology of the DLC:Al films were characterized by X-ray photoelectron spectroscopy (XPS), micro-scratch testing and atomic force microscopy (AFM), respectively. The corrosion performance of the DLC:Al films was investigated by means of potentiodynamic polarization testing in a 0.6 M NaCl aqueous solution. The results showed that the polarization resistance of the DLC:Al films increased from about 18 to 30.7 k(omega) though the corrosion potentials of the films shifted to more negative values with increased Al content in the films.

  20. Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

    International Nuclear Information System (INIS)

    Khun, N.W.; Liu, E.

    2009-01-01

    Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 o C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp 3 -bonded cross-link structure that was significantly affected by the substrate temperature.

  1. Electrically conductive aluminum oxide thin film used as cobalt catalyst-support layer in vertically aligned carbon nanotube growth

    International Nuclear Information System (INIS)

    Azam, Mohd Asyadi; Ismail, Syahriza; Mohamad, Noraiham; Isomura, Kazuki; Shimoda, Tatsuya

    2015-01-01

    This paper will present the unique characteristics of aluminum oxide (Al–O) and cobalt catalyst included in aligned carbon nanotube (CNT) electrode system of energy storage device, namely electrochemical capacitor. Electrical conductivity and nanostructure of the thermally oxidized Al–O used as catalyst-support layer in vertically grown single-walled CNTs were studied. Al–O films were characterized by means of current–voltage measurement and high resolution transmission electron microscopy analysis. The Al–O support layer was found to be conductive, with a relatively low resistance and, approximately 20 nm film thickness of Al–O is suggested to be too thin to form insulating barrier. The scanning TEM—annular dark field analysis confirmed that the nanosized cobalt catalyst particles distributed on Al–O surfaces and also embedded inside the Al–O film structure. (paper)

  2. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes/polymer composite thin film.

    Science.gov (United States)

    Rajanna, Pramod Mulbagal; Gilshteyn, Evgenia; Yagafarov, Timur; Alekseeva, Alena; Anisimov, Anton; Sergeev, Oleg; Neumueller, Alex; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert

    2018-01-09

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and a thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high quality SWCNTs with an enhanced conductivity by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with different SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit Jsc, open-circuit Voc, and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and efficiency of 3.4% under simulated one-sun AM 1.5G direct illumination. © 2018 IOP Publishing Ltd.

  3. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film

    Science.gov (United States)

    Rajanna, Pramod M.; Gilshteyn, Evgenia P.; Yagafarov, Timur; Aleekseeva, Alena K.; Anisimov, Anton S.; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G.

    2018-03-01

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

  4. Investigation of Physical Properties and Electrochemical Behavior of Nitrogen-Doped Diamond-Like Carbon Thin Films

    Directory of Open Access Journals (Sweden)

    Rattanakorn Saensak

    2014-03-01

    Full Text Available This work reports characterizations of diamond-like carbon (DLC films used as electrodes for electrochemical applications. DLC thin films are prepared on glass slides and silicon substrates by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD using a gas mixture of methane and hydrogen. In addition, the DLC films are doped with nitrogen in order to reduce electrical resistivity. Compared to the undoped DLC films, the electrical resistivity of nitrogen-doped (N-doped DLC films is decreased by three orders of magnitude. Raman spectroscopy and UV/Vis spectroscopy analyses show the structural transformation in N-doped DLC films that causes the reduction of band gap energy. Contact angle measurement at N-doped DLC films indicates increased hydrophobicity. The results obtained from the cyclic voltammetry measurements with Fe(CN63-/Fe(CN64- redox species exhibit the correlation between the physical properties and electrochemical behavior of DLC films.

  5. Effect of carbon additive on microstructure evolution and magnetic properties of epitaxial FePt (001) thin films

    International Nuclear Information System (INIS)

    Ding, Y.F.; Chen, J.S.; Liu, E.; Lim, B.C.; Hu, J.F.; Liu, B.

    2009-01-01

    FePt:C thin films were deposited on CrRu underlayers by DC magnetron co-sputtering. The effects of C content, FePt:C film thickness and substrate temperature on the microstructural and magnetic properties of the epitaxial FePt (001) films were studied. Experimental results showed that even with 30 vol.% C doping, the FePt films could keep a (001) preferred orientation at 350 deg. C . When a FePt:C film was very thin (< 5 nm), the film had a continuous microstructure instead of a granual structure with C diffused onto the film surface. With further increased film thickness, the film started to nucleate and formed a column microstructure over continuous FePt films. A strong exchange coupling in the FePt:C films was believed to be due to the presence of a thin continuous FePt layer attributed to the carbon diffusion during the initial stage of the FePt:C film growth. Despite the presence of a strong exchange coupling in the FePt:C (20 vol.% C) film, the SNR ratio of the FePt:C media was about 10 dB better than that of the pure FePt media. The epitaxial growth of the FePt:C films on the Pt layers was observed from high resolution TEM cross sectional images even for the films grown at about 200 deg. C . The TEM images did not show an obvious change in the morphology of the FePt:C films deposited at different temperatures (from 200 deg. C to 350 deg. C ), though the ordering degree and coercivity of the films increased with increased substrate temperature

  6. Nonlinear optical properties of polyaniline and poly (o-toluidine) composite thin films with multi walled carbon nano tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nagaraja, K.K. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Pramodini, S. [Department of Physics, School of Engineering and Technology, Jain University, Jakkasandra Post, Bengaluru 5621112, Karnataka (India); Poornesh, P., E-mail: poorneshp@gmail.com [Nonlinear Optics Research Laboratory, Department of Physics, Manipal Institute of Technology, Manipal University, Manipal 576 104, Karnataka (India); Telenkov, M.P. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Kityk, I.V. [Electrical Engineering Department, Czestochowa University Technology, Czestochowa (Poland)

    2017-05-01

    We report the improved third-order nonlinear optical properties of polyaniline and poly (o-toluidine) with different doping concentrations of multi walled carbon nano tube (MWCNTs) composite thin films investigated using z-scan technique and continuous wave He–Ne laser at 633 nm wavelength was used as source of excitation. Thin films were prepared by spin coating technique on glass substrate. The structural properties of the composite films were analysed by X-ray diffraction studies and the characteristic peaks corresponding to MWCNTs and polymers have been observed. The surface morphology of the deposited films was analysed using scanning electron microscopy and it confirms that the polymer in the composites has been coated on the MWCNTs homogeneously. The z-scan results reveal that the films exhibit reverse saturable absorption and self-defocusing nonlinearity. The third-order nonlinear optical susceptibility χ{sup (3)} is found to be of the order of 10{sup −3} esu. Also, optical power limiting and clamping experiment was performed. The clamping values increases with increase in concentration and the lowest clamping observed for composite films are 1 mW and 0.7 mW.

  7. Light emission in forward and reverse bias operation in OLED with amorphous silicon carbon nitride thin films

    Science.gov (United States)

    Reyes, R.; Cremona, M.; Achete, C. A.

    2011-01-01

    Amorphous silicon carbon nitride (a-SiC:N) thin films deposited by magnetron sputtering were used in the structure of an organic light emitting diode (OLED), obtaining an OLED operating in forward and reverse bias mode. The device consist of the heterojunction structure ITO/a-SiC:N/Hole Transport Layer (HTL)/ Electron Transport Layer (ETL)/a-SiC:N/Al. As hole transporting layer was used a thin film of 1-(3-methylphenyl)-1,2,3,4 tetrahydroquinoline - 6 - carboxyaldehyde - 1,1'- diphenylhydrazone (MTCD), while the tris(8-hydroxyquinoline aluminum) (Alq3) is used as electron transport and emitting layer. A significant increase in the voltage operation compared to the conventional ITO/MTCD/Alq3/Al structure was observed, so the onset of electroluminescence occurs at about 22 V in the forward and reverse bias mode of operation. The electroluminescence spectra is similar in both cases, only slightly shifted 0.14 eV to lower energies in relation to the conventional device.

  8. Light emission in forward and reverse bias operation in OLED with amorphous silicon carbon nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R [Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Av. Tupac Amaru SN, Lima (Peru); Cremona, M [Departamento de Fisica, PontifIcia Universidade Catolica de Rio de Janeiro, PUC-Rio, Cx. Postal 38071, Rio de Janeiro, RJ, CEP 22453-970 (Brazil); Achete, C A, E-mail: rreyes@uni.edu.pe [Departamento de Engenheria Metalurgica e de Materiais, Universidade Federal do Rio de Janeiro, Cx. Postal 68505, Rio de Janeiro, RJ, CEP 21945-970 (Brazil)

    2011-01-01

    Amorphous silicon carbon nitride (a-SiC:N) thin films deposited by magnetron sputtering were used in the structure of an organic light emitting diode (OLED), obtaining an OLED operating in forward and reverse bias mode. The device consist of the heterojunction structure ITO/a-SiC:N/Hole Transport Layer (HTL)/ Electron Transport Layer (ETL)/a-SiC:N/Al. As hole transporting layer was used a thin film of 1-(3-methylphenyl)-1,2,3,4 tetrahydroquinoline - 6 - carboxyaldehyde - 1,1'- diphenylhydrazone (MTCD), while the tris(8-hydroxyquinoline aluminum) (Alq{sub 3}) is used as electron transport and emitting layer. A significant increase in the voltage operation compared to the conventional ITO/MTCD/Alq{sub 3}/Al structure was observed, so the onset of electroluminescence occurs at about 22 V in the forward and reverse bias mode of operation. The electroluminescence spectra is similar in both cases, only slightly shifted 0.14 eV to lower energies in relation to the conventional device.

  9. Light emission in forward and reverse bias operation in OLED with amorphous silicon carbon nitride thin films

    International Nuclear Information System (INIS)

    Reyes, R; Cremona, M; Achete, C A

    2011-01-01

    Amorphous silicon carbon nitride (a-SiC:N) thin films deposited by magnetron sputtering were used in the structure of an organic light emitting diode (OLED), obtaining an OLED operating in forward and reverse bias mode. The device consist of the heterojunction structure ITO/a-SiC:N/Hole Transport Layer (HTL)/ Electron Transport Layer (ETL)/a-SiC:N/Al. As hole transporting layer was used a thin film of 1-(3-methylphenyl)-1,2,3,4 tetrahydroquinoline - 6 - carboxyaldehyde - 1,1'- diphenylhydrazone (MTCD), while the tris(8-hydroxyquinoline aluminum) (Alq 3 ) is used as electron transport and emitting layer. A significant increase in the voltage operation compared to the conventional ITO/MTCD/Alq 3 /Al structure was observed, so the onset of electroluminescence occurs at about 22 V in the forward and reverse bias mode of operation. The electroluminescence spectra is similar in both cases, only slightly shifted 0.14 eV to lower energies in relation to the conventional device.

  10. Stable, Microfabricated Thin Layer Chromatography Plates without Volume Distortion on Patterned, Carbon and Al2O3-Primed Carbon Nanotube Forests

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, David S.; Kanyal, Supriya S.; Gupta, Vipul; Vail, Michael A.; Dadson, Andrew; Engelhard, Mark H.; Vanfleet, Richard; Davis, Robert C.; Linford, Matthew R.

    2012-09-28

    In a recent report (Song, J.; et al., Advanced Functional Materials 2011, 21, 1132-1139) some of us described the fabrication of thin layer chromatography (TLC) plates from patterned carbon nanotube (CNT) forests, which were directly infiltrated/coated with silicon by low pressure chemical vapor deposition (LPCVD) of silicon using SiH4. Following infiltration, the nanotubes were removed from the assemblies and the silicon simultaneously converted to SiO2 in a high temperature oxidation step. However, while straightforward, this process had some shortcomings, not the least of which was some distortion of the lithographically patterned features during the volume expansion that accompanied oxidation. Herein we overcome theis issue and also take substantial steps forward in the microfabrication of TLC plates by showing: (i) A new method for creating an adhesion promotion layer on CNT forests by depositing a few nanometers of carbon followed by atomic layer deposition (ALD) of Al2O3. This method for appears to be new, and X-ray photoelectron spectroscopy confirms the expected presence of oxygen after carbon deposition. ALD of Al2O3 alone and in combination with the carbon on patterned CNT forests was also explored as an adhesion promotion layer for CNT forest infiltration. (ii) Rapid, conformal deposition of an inorganic material that does not require subsequent oxidation: fast pseudo-ALD growth of SiO2 via alumina catalyzed deposition of tris(tert-butoxy)silanol onto the carbon/Al2O3-primed CNT forests. (iii) Faithful reproduction of the features in the masks used to microfabricate the TLC plates (M-TLC) this advance springs from the previous two points. (iv) A bonded (amino) phase on a CNT-templated microfabricated TLC plate. (v) Fast, highly efficient (125,000 - 225,000 N/m) separations of fluorescent dyes on M-TLC plates. (vi) Extensive characterization of our new materials by TEM, SEM, EDAX, DRIFT, and XPS. (vii) A substantially lower process temperature for the

  11. Structured nanocarbon on various metal foils by microwave plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Rius, G; Yoshimura, M

    2013-01-01

    We present a versatile process for the engineering of nanostructures made of crystalline carbon on metal foils. The single step process by microwave plasma-enhance chemical vapor deposition is demonstrated for various substrate materials, such as Ni or Cu. Either carbon nanotubes (CNT) or carbon nanowalls (CNW) are obtained under same growth conditions and without the need of additional catalyst. The use of spacer and insulator implies a certain control over the kind of allotropes that are obtained. High density and large surface area are morphological characteristics of the thus obtained C products. The possibility of application on many metals, and in the alloy composition, on as-delivered commercially available foils indicates that this strategy can be adapted to a bunch of specific applications, while the production of C nanostructures is of remarkable simplicity.

  12. LENA Conversion Foils Using Single-Layer Graphene, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our key innovation will be the use of single-layer graphene as LENA conversion foils, with appropriate microgrids and nanogrids to support the foils. Phase I...

  13. Particle velocity measurements in laser irradiated foils using ORVIS

    International Nuclear Information System (INIS)

    Sheffield, S.A.; Fisk, G.A.

    1983-01-01

    Aluminum foils from 2- to 200-μm thick have been subjected to a Nd:YAG laser pulse of low irradiance (10 9 W/cm 2 , approx. 10 ns pulse) to produce laser-driven shocks in the foils. The particle velocity history of the foil side opposite the laser deposition was monitored with nanosecond resolution by a velocity interferometer system called ORVIS. These histories indicate a shock reverberation process accelerates the foil. Peak foil velocities can be adequately calculated using a ricket propulsion model developed from experiments at much higher irradiances. A velocity of 1 km/s was developed in a 2-μm-thick free foil in a time of 50 ns. Water-confined foils attained peak particle velocities about three times higher than those of free foils

  14. Examination of the picture properties of luminescence memory foils

    International Nuclear Information System (INIS)

    Ewert, U.; Heine, S.; Nockemann, C.; Stade, J.; Tillack, G.R.; Wessel, H.; Zscherpel, U.; Mattis, A.

    1995-01-01

    Luminescence memory foils are a new medium for radiography without films. They are known by the name of image plates or digital memory foils. The suitability of such systems for industrial radiography is examined. (orig.) [de

  15. The Fluid Foil: The Seventh Simple Machine

    Science.gov (United States)

    Mitts, Charles R.

    2012-01-01

    A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

  16. Foil Panel Mirrors for Nonimaging Applications

    Science.gov (United States)

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

    1984-01-01

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

  17. Vortex wakes of a flapping foil

    DEFF Research Database (Denmark)

    Schnipper, Teis; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present an experimental study of a symmetric foil performing pitching oscillations in a vertically flowing soap film. By varying the frequency and amplitude of the oscillation we visualize a variety of wakes with up to 46 vortices per oscillation period, including von Karman vortex street...

  18. Utilization of carbon dioxide by Chlorella kessleri in outdoor open thin-layer culture units

    Czech Academy of Sciences Publication Activity Database

    Lívanský, Karel; Doucha, Jiří

    2005-01-01

    Roč. 116, - (2005), s. 201-212 ISSN 0342-1120 R&D Projects: GA ČR GV104/97/S055 Institutional research plan: CEZ:AV0Z50200510 Keywords : chlorella kessleri * carbon dioxide * microalga Subject RIV: EE - Microbiology, Virology

  19. Forming of electron beams from a betatron by foils scatterers

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A P; Shishov, V A [N.N. Petrov Research Inst. of Oncology, Leningrad (USSR). Laboratory of High Energics

    1976-12-01

    The technique of forming electron beams by one scattering foil and one compensating foil is discussed. This method provides a means for producing large-size uniform dose distributions with much smaller losses in dose rate as compared with conventional beam forming by ine foil. Moreover, the energy losses involved in this process and the background of concomitant bremsstrahlung are much less. A techinque of calculation to determine approximate parameters of the compensating foils is described.

  20. Tungsten foil laminate for structural divertor applications – Joining of tungsten foils

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, Jens, E-mail: jens.reiser@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM-AWP) (Germany); Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM-AWP) (Germany); Mrotzek, Tobias; Hoffmann, Andreas [PLANSEE SE, Reutte (Austria); Armstrong, D.E.J.; Yi, Xiaoou [University of Oxford, Department of Materials (United Kingdom)

    2013-05-15

    This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

  1. Tungsten foil laminate for structural divertor applications - Joining of tungsten foils

    Science.gov (United States)

    Reiser, Jens; Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan; Mrotzek, Tobias; Hoffmann, Andreas; Armstrong, D. E. J.; Yi, Xiaoou

    2013-05-01

    This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

  2. Low mass MEMS/NEMS switch for a substitute of CMOS transistor using single-walled carbon nanotube thin film

    Science.gov (United States)

    Jang, Min-Woo

    Power dissipation is a key factor for mobile devices and other low power applications. Complementary metal oxide semiconductor (CMOS) is the dominant integrated circuit (IC) technology responsible for a large part of this power dissipation. As the minimum feature size of CMOS devices enters into the sub 50 nanometer (nm) regime, power dissipation becomes much worse due to intrinsic physical limits. Many approaches have been studied to reduce power dissipation of deeply scaled CMOS ICs. One possible candidate is the electrostatic electromechanical switch, which could be fabricated with conventional CMOS processing techniques. They have critical advantages compared to CMOS devices such as almost zero standby leakage in the off-state due to the absence of a pn junction and a gate oxide, as well as excellent drive current in the on-state due to a metallic channel. Despite their excellent standby power dissipation, the electrostatic MEMS/NEMS switches have not been considered as a viable replacement for CMOS devices due to their large mechanical delay. Moreover, previous literature reveals that their pull-in voltage and switching speed are strongly proportional to each other. This reduces their potential advantage. However, in this work, we theoretically and experimentally demonstrated that the use of single-walled carbon nanotube (SWNT) with very low mass density and strong mechanical properties could provide a route to move off of the conventional trend with respect to the pull-in voltage / switching speed tradeoff observed in the literature. We fabricated 2-terminal fixed- beam switches with aligned composite SWNT thin films. In this work, layer-by-layer (LbL) self-assembly and dielectrophoresis were selected for aligned-composite SWNT thin film deposition. The dense membranes were successfully patterned to form submicron beams by e-beam lithography and oxygen plasma etching. Fixed-fixed beam switches using these membranes successfully operated with approximately 600

  3. Characterization of diamond-like carbon thin film synthesized by RF atmospheric pressure plasma Ar/CH4 jet

    Science.gov (United States)

    Sohbatzadeh, Farshad; Safari, Reza; Etaati, G. Reza; Asadi, Eskandar; Mirzanejhad, Saeed; Hosseinnejad, Mohammad Taghi; Samadi, Omid; Bagheri, Hanieh

    2016-01-01

    The growth of diamond like carbon (DLC) on a Pyrex glass was investigated by a radio frequency (RF) atmospheric pressure plasma jet (APPJ). The plasma jet with capacitive configuration ran by a radio frequency power supply at 13.56 MHz. Alumina ceramic was used as dielectric barrier. Ar and CH4 were used in atmospheric pressure as carrier and precursor gases, respectively. Diamond like carbon thin films were deposited on Pyrex glass at substrate temperature and applied power of 130 °C and 250 Watts, respectively. Performing field emission scanning electron microscope (FE-SEM) and laser Raman spectroscopy analysis resulted in deposition rate and the ID/IG ratio of 21.31 nm/min and 0.47, respectively. The ID/IG ratio indicated that the coating possesses relative high sp3 content The optical emission spectroscopy (OES) diagnostic was applied to diagnose plasma jet species. Estimating electron temperature and density of the RF-APPJ resulted in 1.36 eV and 2.75 × 1014 cm-3 at the jet exit, respectively.

  4. Study of nanometric thin pyrolytic carbon films for explosive electron emission cathode in high-voltage planar diode

    Energy Technology Data Exchange (ETDEWEB)

    Baryshevsky, Vladimir; Belous, Nikolai; Gurinovich, Alexandra; Gurnevich, Evgeny [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya Str. 11, Minsk 220030 (Belarus); Kuzhir, Polina, E-mail: polina.kuzhir@gmail.com [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya Str. 11, Minsk 220030 (Belarus); National Research Tomsk State University, 36 Lenin Prospekt, Tomsk 634050 (Russian Federation); Maksimenko, Sergey [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya Str. 11, Minsk 220030 (Belarus); National Research Tomsk State University, 36 Lenin Prospekt, Tomsk 634050 (Russian Federation); Molchanov, Pavel; Shuba, Mikhail [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya Str. 11, Minsk 220030 (Belarus); Roddatis, Vladimir [CIC energiGUNE, Albert Einstein 48, 01510 Minano, Alava (Spain); Institut für Materialphysik of Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Kaplas, Tommi; Svirko, Yuri [Institute of Photonics, University of Eastern Finland, P.O. Box 111, Joensuu FI-80101 (Finland)

    2015-04-30

    We report on an experimental study of explosive electron emission properties of cathode made by nanometric thin pyrolytic carbon (PyC) films (2–150 nm) deposited on Cu substrate via methane-based chemical vapor deposition. High current density at level of 300 A/cm{sup 2} in 5 · 10{sup −5} Pa vacuum has been observed together with very stable explosive emission from the planar cathode. The Raman spectroscopy investigation proves that the PyC films remain the same after seven shots. According to the optical image analysis of the cathode before and after one and seven shots, we conclude that the most unusual and interesting feature of using the PyC films/Cu cathode for explosive emission is that the PyC layer on the top of the copper target prevents its evaporation and oxidation, which leads to higher emission stability compared to conventional graphitic/Cu cathodes, and therefore results in longer working life. - Highlights: • Explosive electron emission from pyrolytic carbon (PyC) cathode is reported. • We observe high current density, 300 A/cm{sup 2}, and stable emission parameters. • PyC integrity ensures a high application potential for high current electronics.

  5. Scaling laws for radial foil bearings

    Science.gov (United States)

    Honavara Prasad, Srikanth

    The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

  6. Stripping foils for the PSB H- injection system

    CERN Document Server

    Aiba, M; Goddard, B; Weterings, W

    2009-01-01

    Beam physics considerations for the stripping foil of the PSB H- injection system are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The required movement ranges and tolerances are detailed, together with the assumptions used.

  7. EBSD analysis of plastic deformation of copper foils by flexible pad laser shock forming

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, Balasubramanian; Castagne, Sylvie [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore (Singapore); Wang, Zhongke; Zheng, H.Y. [Nanyang Technological University, SIMTech-NTU Joint Laboratory (Precision Machining), Singapore (Singapore); Singapore Institute of Manufacturing Technology, Machining Technology Group, Singapore (Singapore)

    2015-11-15

    Flexible pad laser shock forming (FPLSF) is a new mold-free microforming process that induces high-strain-rate plastic deformation in thin metallic foils using laser-induced shock pressure and a hyperelastic flexible pad. This paper studies the plastic deformation behavior of copper foils formed through FPLSF by investigating surface hardness and microstructure. The microstructure of the foil surface before and after FPLSF is analyzed by electron backscatter diffraction technique using grain size distribution and grain boundary misorientation angle as analysis parameters. The surface hardness of the craters experienced a significant improvement after FPLSF; the top crater surface being harder than the bottom surface. The microstructure of the copper foil surface after FPLSF was found to be dominated by grain elongation, along with minor occurrences of subgrain formation, grain refinement, and high dislocation density regions. The results indicate that the prominent plastic deformation mechanism in FPLSF is strain hardening behavior rather than the typical adiabatic softening effect known to be occurring at high-strain-rates for processes such as electromagnetic forming, explosive forming, and laser shock forming. This significant difference in FPLSF is attributed to the concurrent reduction in plastic strain, strain rate, and the inertia effects, resulting from the FPLSF process configuration. Correspondingly, different deformation behaviors are experienced at top and bottom surfaces of the deformation craters, inducing the change in surface hardness and microstructure profiles. (orig.)

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

    Science.gov (United States)

    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.

  9. Deposit of thin films of nitrided amorphous carbon using the laser ablation technique; Deposito de peliculas delgadas de carbono amorfo nitrurado utilizando la tecnica de ablacion laser

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo, P.B.; Escobar A, L.; Camps C, E. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Salazar, Estado de Mexico (Mexico); Haro P, E.; Camacho L, M.A. [Departamento de Fisica, Universidad Autonoma Metropolitana Iztapalapa (Mexico); Muhl S, S. [Instituto de Investigacion en Materiales, UNAM (Mexico)

    2000-07-01

    It is reported the synthesis and characterization of thin films of amorphous carbon (a-C) nitrided, deposited by laser ablation in a nitrogen atmosphere at pressures which are from 4.5 x 10 {sup -4} Torr until 7.5 x 10 {sup -2} Torr. The structural properties of the films are studied by Raman spectroscopy obtaining similar spectra at the reported for carbon films type diamond. The study of behavior of the energy gap and the ratio nitrogen/carbon (N/C) in the films, shows that the energy gap is reduced when the nitrogen incorporation is increased. It is showed that the refraction index of the thin films diminish as nitrogen pressure is increased, indicating the formation of graphitic material. (Author)

  10. Activated carbon/manganese dioxide hybrid electrodes for high performance thin film supercapacitors

    Science.gov (United States)

    Jang, Yunseok; Jo, Jeongdai; Jang, Hyunjung; Kim, Inyoung; Kang, Dongwoo; Kim, Kwang-Young

    2014-06-01

    We combine the activated carbon (AC) and the manganese dioxide (MnO2) in a AC/MnO2 hybrid electrode to overcome the low capacitance of activated carbon and MnO2 by exploiting the large surface area of AC and the fast reversible redox reaction of MnO2. An aqueous permanganate (MnO4 -) is converted to MnO2 on the surface of the AC electrode by dipping the AC electrode into an aqueous permanganate solution. The AC/MnO2 hybrid electrode is found to display superior specific capacitance of 290 F/g. This shows that supercapacitors classified as electric double layer capacitors and pseudocapacitors can be combined together.

  11. TEM investigation of DC sputtered carbon-nitride-nickel thin films

    International Nuclear Information System (INIS)

    Safran, G.; Geszti, O.; Radnoczi, G.

    2002-01-01

    Deposition of carbon nitride (C-N) and carbon-nitride-nickel (C-N-Ni) films onto glass, NaCl and Si(001) substrates was carried out in a dc magnetron sputtering system. Carbon was deposited from high-purity (99.99%) pyrolytic graphite target, 50 mm in diameter, positioned at 10 cm from a resistance-heated substrate holder. C-N-Ni films were grown by a small Ni plate mounted on the graphite target. The base pressure of the deposition chamber was ∼7x10 -7 Torr. Films were grown at a substrate temperature of 20-700 grad C, in pure N 2 at partial pressures of 1.9 -2.2 mTorr and the substrates were held at ground potential. The typical film thickness of 15-30 nm was deposited on all the substrates at a magnetron current of 0.2 and 0.3 A, which resulted in a deposition rate of 1.5-2 nm/s. Structural characterizations were performed by high-resolution transmission electron microscopy (HRTEM) using a JEOL 3010 operated at 300 kV and a 200 kV Philips CM 20 electron microscope equipped with a Ge detector Noran EDS system. The N content of the C-N samples prepared at room temperature was 22-24% by EDS measurement and showed a decrease to 6-7% at elevated temperatures up to 700 grad C. The N concentration in the C-N-Ni films was higher: ∼38% at RT and ∼9% at 700 grad C. The Ni concentration of C-N-Ni samples was 5-6% and 0.3-0.4% in samples deposited at RT and 700 grad C respectively. The low Ni content in the latter is attributed to a decrease of the sticking coefficient of the carbon co-deposited Ni at elevated temperatures. (Authors)

  12. Pulsed laser deposition and characterization of multilayer metal-carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Siraj, K., E-mail: khurram.uet@gmail.com [Advance Physics Laboratory, Department of Physics, University of Engineering and Technology, Lahore (Pakistan); Khaleeq-ur-Rahman, M.; Rafique, M.S.; Munawar, M.Z. [Advance Physics Laboratory, Department of Physics, University of Engineering and Technology, Lahore (Pakistan); Naseem, S.; Riaz, S. [Center for Solid State Physics, University of Punjab, Lahore (Pakistan)

    2011-05-15

    Cobalt-DLC multilayer films were deposited with increasing content of cobalt, keeping carbon content constant by pulsed laser deposition technique. A cobalt free carbon film was also deposited for comparison. Excimer laser was employed to ablate the materials onto silicon substrate, kept at 250 deg. C, while post-deposition annealing at 400 deg. C was also performed in situ. The formation of cobalt grains within the carbon matrix in Co-DLC films can be seen through scanning electron and atomic force micrographs while no grains on the surface of the cobalt-free DLC film were observed. Raman spectra of all the films show D- and G-bands, which is a confirmation that the films are DLC in nature. According to Vibrating sample magnetometer (VSM) measurements, the DLC films with cobalt revealed ferromagnetic behaviour whereas the cobalt free DLC film exhibited diamagnetic behaviour. The pure DLC film also shows ferromagnetic nature when diamagnetic background is subtracted. Spectroscopic Ellipsometry (SE) analysis showed that the optical band gaps, refractive indices and extinction coefficients of Co-DLC films can be effectively tuned with increasing content of cobalt.

  13. Pulsed laser deposition and characterization of multilayer metal-carbon thin films

    International Nuclear Information System (INIS)

    Siraj, K.; Khaleeq-ur-Rahman, M.; Rafique, M.S.; Munawar, M.Z.; Naseem, S.; Riaz, S.

    2011-01-01

    Cobalt-DLC multilayer films were deposited with increasing content of cobalt, keeping carbon content constant by pulsed laser deposition technique. A cobalt free carbon film was also deposited for comparison. Excimer laser was employed to ablate the materials onto silicon substrate, kept at 250 deg. C, while post-deposition annealing at 400 deg. C was also performed in situ. The formation of cobalt grains within the carbon matrix in Co-DLC films can be seen through scanning electron and atomic force micrographs while no grains on the surface of the cobalt-free DLC film were observed. Raman spectra of all the films show D- and G-bands, which is a confirmation that the films are DLC in nature. According to Vibrating sample magnetometer (VSM) measurements, the DLC films with cobalt revealed ferromagnetic behaviour whereas the cobalt free DLC film exhibited diamagnetic behaviour. The pure DLC film also shows ferromagnetic nature when diamagnetic background is subtracted. Spectroscopic Ellipsometry (SE) analysis showed that the optical band gaps, refractive indices and extinction coefficients of Co-DLC films can be effectively tuned with increasing content of cobalt.

  14. Deuteriding of thin titanium films: the effect of carbon monoxide surface contamination

    International Nuclear Information System (INIS)

    Malinowski, M.W.

    1976-02-01

    The effect of adsorbed CO on the deuteriding of thin titanium films at room temperature was measured at D 2 pressures between 10 to 25 mtorr on films contaminated with CO exposures ranging between approximately 10 -8 torr-seconds (''clean'') to 10 -4 torr-seconds. In all measurements, for deuterium/titanium atom ratios greater than .2, the deuteriding appeared to be initally limited by the sticking of D 2 on the clean or contaminated titanium deuteride surface; the effective sticking coefficient on a clean titanium deuteride surface was approximately 3 x 10 -3 , while on a surface contaminated with 10 -4 torr-seconds of CO, the coefficient was reduced to approximately, 2 x 10 -4 . The pumping speeds of Ti films were dramatically different when the films were evaporated over TiD 2 . These changes were attributed to the presence of deuterium which diffused from the substrate film into the overlayer film

  15. Fabricating 40 µm-thin silicon solar cells with different orientations by using SLiM-cut method

    Science.gov (United States)

    Wang, Teng-Yu; Chen, Chien-Hsun; Shiao, Jui-Chung; Chen, Sung-Yu; Du, Chen-Hsun

    2017-10-01

    Thin silicon foils with different crystal orientations were fabricated using the stress induced lift-off (SLiM-cut) method. The thickness of the silicon foils was approximately 40 µm. The ≤ft foil had a smoother surface than the ≤ft foil. With surface passivation, the minority carrier lifetimes of the ≤ft and ≤ft silicon foil were 1.0 µs and 1.6 µs, respectively. In this study, 4 cm2-thin silicon solar cells with heterojunction structures were fabricated. The energy conversion efficiencies were determined to be 10.74% and 14.74% for the ≤ft and ≤ft solar cells, respectively. The surface quality of the silicon foils was determined to affect the solar cell character. This study demonstrated that fabricating the solar cell by using silicon foil obtained from the SLiM-cut method is feasible.

  16. Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation; Sintesis y caracterizacion de peliculas delgadas de carbono amorfo nitrurado, depositadas por ablacion laser

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo P, B

    2001-07-01

    The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp{sup 2} and sp{sup 3} bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

  17. Characterization of beryllium foil produced by hot rolling

    International Nuclear Information System (INIS)

    Wittenauer, J.; Nieh, T.G.; Waychunas, G.

    1992-01-01

    Beryllium foil is important for a number of aerospace applications including honeycomb structures and metal-matrix composites. In this study, a method of producing beryllium foil directly from powder or flake is demonstrated. A variety of foils were produced in the thickness range 90-300 μm, free from defects such as pinholes and excessive surface roughness, and exhibiting sufficient formability for honeycomb manufacture. Foil produced directly from powder or flake exhibits crystallographic texture, microstructure, and formability equivalent to foil produced from more massive precursors. (Author)

  18. Nuclear target foil fabrication for the Romano Event

    International Nuclear Information System (INIS)

    Weed, J.W.; Romo, J.G. Jr.; Griggs, G.E.

    1984-01-01

    The Vacuum Processes Lab, of LLNL's M.E. Dept. - Material Fabrication Division, was requested to provide 250 coated Parylene target foils for a nuclear physics experiment titled the ROMANO Event. Due to the developmental nature of some of the fabrication procedures, approximately 400 coated foils were produced to satisfy the event's needs. The foils were used in the experiment as subkilovolt x-ray, narrow band pass filters, and wide band ultraviolet filters. This paper is divided into three sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, and (3) foil and substrate inspections

  19. Medium-scale carbon nanotube thin-film integrated circuits on flexible plastic substrates.

    Science.gov (United States)

    Cao, Qing; Kim, Hoon-sik; Pimparkar, Ninad; Kulkarni, Jaydeep P; Wang, Congjun; Shim, Moonsub; Roy, Kaushik; Alam, Muhammad A; Rogers, John A

    2008-07-24

    The ability to form integrated circuits on flexible sheets of plastic enables attributes (for example conformal and flexible formats and lightweight and shock resistant construction) in electronic devices that are difficult or impossible to achieve with technologies that use semiconductor wafers or glass plates as substrates. Organic small-molecule and polymer-based materials represent the most widely explored types of semiconductors for such flexible circuitry. Although these materials and those that use films or nanostructures of inorganics have promise for certain applications, existing demonstrations of them in circuits on plastic indicate modest performance characteristics that might restrict the application possibilities. Here we report implementations of a comparatively high-performance carbon-based semiconductor consisting of sub-monolayer, random networks of single-walled carbon nanotubes to yield small- to medium-scale integrated digital circuits, composed of up to nearly 100 transistors on plastic substrates. Transistors in these integrated circuits have excellent properties: mobilities as high as 80 cm(2) V(-1) s(-1), subthreshold slopes as low as 140 m V dec(-1), operating voltages less than 5 V together with deterministic control over the threshold voltages, on/off ratios as high as 10(5), switching speeds in the kilohertz range even for coarse (approximately 100-microm) device geometries, and good mechanical flexibility-all with levels of uniformity and reproducibility that enable high-yield fabrication of integrated circuits. Theoretical calculations, in contexts ranging from heterogeneous percolative transport through the networks to compact models for the transistors to circuit level simulations, provide quantitative and predictive understanding of these systems. Taken together, these results suggest that sub-monolayer films of single-walled carbon nanotubes are attractive materials for flexible integrated circuits, with many potential areas of

  20. New insight into the mechanism of cathodic electrodeposition of zinc oxide thin films onto vitreous carbon

    OpenAIRE

    Ait Ahmed , N.; Eyraud , M.; Hammache , H.; Vacandio , F.; Sam , S.; Gabouze , N.; Knauth , P.; Pelzer , K.; Djenizian , T.

    2014-01-01

    International audience; In this study, the mechanism of zinc oxide (ZnO) electrodeposition from aqueous zinc nitrate solution at 70°C was investigated on vitreous carbon and bulk zinc electrodes using cyclic voltammetry experiments. Mechanisms are presented for the ZnO formation: the first widely accepted route corresponds to ZnO precipitation from Zn 2+ and OH-produced by NO3-reduction; the second route, which is discussed in this article, is due to Zn 2+ reduction into metallic Zn followed ...