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Sample records for bombarding insulating foils

  1. Vacuum foil insulation system

    International Nuclear Information System (INIS)

    Hanson, J.P.; Sabolcik, R.E.; Svedberg, R.C.

    1976-01-01

    In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. Assembly of the insulation package with the skirted cup is facilitated by splitting the cup to allow it to be opened up and fitted around the other cups during assembly. The insulation is for an implantable nuclear powered artificial heart

  2. Characterization techniques for ion bombarded insulators

    International Nuclear Information System (INIS)

    Borders, J.A.

    1987-01-01

    The chapter gives a comprehensive review of the experimental methods for the analysis of ion-bombarded insulators including optical and structural methods, resonance, energetic ion methods, and surface techniques. 48 refs.; 34 figs

  3. Foil analysis of 1.5-GeV proton bombardment of a mercury target

    CERN Document Server

    Charlton, L A; Glasgow, D C; Gabriel, T A

    1999-01-01

    The number of reactant nuclei in a series of foils surrounding a container of mercury that has been bombarded by 1.5-GeV protons is calculated and compared with experimental measurements. This procedure is done to aid in the validation of the mercury cross sections used in the design studies of the Spallation Neutron Source (SNS). It is found that the calculations match the measurements to within the uncertainties inherent in the analysis.

  4. Determination of neutron spectra formed by 40-MeV deuteron bombardment of a lithium target with multi-foil activation technique

    CERN Document Server

    Maekawa, F; Wada, M; Wilson, P P H; Ikeda, Y

    2000-01-01

    Neutron flux spectra at an irradiation field produced by a 40-MeV deuteron bombardment on a thick lithium-target at Forschungszentrum Karlsruhe, Germany, have been determined by the multi-foil activation technique. Twenty-seven dosimetry reactions having a wide energy range of threshold energies up to 38 MeV were employed as detectors for the neutron flux spectra extending to 55 MeV. The spectra were adjusted with the SAND-II code with the experimental reaction rates based on an iterative method. The adjusted spectra validated quantitatively the Monte Carlo deuteron-lithium (d-Li) neutron source model code (M sup C DeLi) which was used to calculate initial guess spectra and also has been used for IFMIF nuclear designs. Accuracy of the adjusted spectra was approx 10% that was suitable for successive integral tests of activation cross section data.

  5. 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

  6. 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.

  7. 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.)

  8. Transportation of perishable and refrigerated foods in mylar foil bags and insulated containers: a time-temperature study.

    Science.gov (United States)

    Li, Yanyan; Schrade, John P; Su, Haiyan; Specchio, John J

    2014-08-01

    Data are lacking on the temperature changes of food during transport without the use of refrigerated trucks. The purpose of this study was to evaluate the ability of several insulated and noninsulated containers with or without frozen gel packs to keep perishable and refrigerated foods within the temperature safe zone in relationship to duration of transport. The study was designed to duplicate the practices exhibited by customers purchasing perishable food products from a cash-and-carry business. Approximately 40 perishable food items were evaluated. Four types of containers were tested: a mylar foil bag, a commercial insulated bag, a generic insulated bag, and a commercial insulated blanket. Mixed foods were placed into these containers with or without frozen gel packs, transported in unrefrigerated vehicles, and monitored for 4 h for temperature changes. Two environmental temperatures, room temperature of 21.1°C and a stress temperature of 37.8°C, were evaluated. The internal temperature and surface temperature of the food products in these containers increased slowly but remained well below the U.S. Food and Drug Administration Food Code requirements. The various containers were similar in their ability to retain coolness. The presence of frozen gel packs dramatically enhanced the cold-holding capacity of the containers. The temperature of foods increased more rapidly when stressed in a heated environment. The containers tested used with the frozen gel packs can keep the surface and internal temperatures of various perishable foods (starting at 4.4°C or less) within the Food Code recommendation of under 21.1°C for 4 h. Cash-and-carry businesses should strongly encourage their retail customers to utilize these containers with frozen gel packs to safely transport perishable foods.

  9. 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)

  10. Optimisation of solar collector foils with transparent thermal insulation. Final report; Optimierung von transparent waermegedaemmten Folien-Speicherkollektoren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Michaelis, M

    1995-02-01

    The report describes storage collector foils which are used as hybrid systems. Contents: State of the art - solar test facility - tests on small test collectors - cost reduction. (HW) [Deutsch] Es wird berichtet ueber Folien-Speicherkollektoren, die als Hybridsysteme zum Einsatz kommen. Inhalt der Arbeit: - Stand der Technik - solare Testanlage - Untersuchungen an kleinen Testkollektoreinheiten - Kostenreduzierung. (HW)

  11. Investigation of the thermal resistance of timber attic spaces with reflective foil and bulk insulation, heat flow up

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Bruno, F.; Saman, W. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, SA 5095 (Australia)

    2011-01-15

    An experimental investigation was undertaken in which the thermal resistance for the heat flow through a typical timber framed pitched roofing system was measured under outdoor conditions for heat flow up. The measured thermal resistance of low resistance systems such as an uninsulated attic space and a reflective attic space compared well with published data. However, with higher thermal resistance systems containing bulk insulation within the timber frame, the measured result for a typical installation was as low as 50% of the thermal resistance determined considering two dimensional thermal bridging using the parallel path method. This result was attributed to three dimensional heat flow and insulation installation defects, resulting from the design and construction method used. Translating these results to a typical house with a 200 m{sup 2} floor area, the overall thermal resistance of the roof was at least 23% lower than the overall calculated thermal resistance including two dimensional thermal bridging. When a continuous layer of bulk insulation was applied to the roofing system, the measured values were in agreement with calculated resistances representing a more reliable solution. (author)

  12. Measurement of excitation yields of low energy prompt γ-ray from proton bombardment of Cr-foils with energies ranging between 1.0 and 3.0 MeV

    International Nuclear Information System (INIS)

    Goncharov, A.

    2014-01-01

    The goal of this work is measurement of differential cross sections for the production of 378 keV γ-rays from the reactions 52 Cr(p,γ1) 53 Mn and 53 Cr(p,nγ1) 53 Mn for proton energies ranging between 1.0 and 3.0 MeV at the laboratory angle of 90° using foils with thickness ∼1.9×10 18 at/cm 2 (∼ 0.23 μm) of nat Cr.

  13. Anomalous heat evolution of deuteron implanted Al on electron bombardment

    International Nuclear Information System (INIS)

    Kamada, K.; Kinoshita, H.; Takahashi, H.

    1994-05-01

    Anomalous heat evolution was observed in deuteron implanted Al foils on 175 keV electron bombardment. Local regions with linear dimension of several 100nm showed simultaneous transformation from single crystalline to polycrystalline structure instantaneously on the electron bombardment, indicating the temperature rise up to more than melting point of Al from room temperature. The amount of energy evolved was more than 180 MeV for each transformed region. The transformation was never observed in proton implanted Al foils. The heat evolution was considered due to a nuclear reaction in D 2 molecular collections. (author)

  14. 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

  15. Effects of uranium bombardment by 20-40 KeV argon ions, Annex 2

    International Nuclear Information System (INIS)

    Nenadovic, T.; Jurela, Z.

    1966-01-01

    This paper shows the results of argon ions interaction with the polycrystal natural uranium. Thin foil of uranium about 200 μ was bombarded by 20-40 KeV argon ions. Coefficients of cathode scattering δ and secondary electrons emission γ were measured, during the process A + →U. The foil was then studied by transmission method and method of single step replica using an electron microscope [sr

  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. 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

  18. Monitoring the degradation of partly decomposable plastic foils

    Directory of Open Access Journals (Sweden)

    Rétháti Gabriella

    2014-11-01

    Full Text Available We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE, MDPE containing pro-oxydative additives (238, 242 and MDPE with pro-oxydative additives and thermoplastic starch (297 in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.

  19. 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

  20. Design considerations for foil windows for PET radioisotope targets

    International Nuclear Information System (INIS)

    Hughey, B.J.; Shefer, R.E.; Klinkowstein, R.E.; Welch, M.J.

    1992-01-01

    This paper describes the results of a study performed at SRL to develop analytical and computational techniques for optimizing the design of conduction-cooled foil windows for PET targets. Single foil conduction cooled windows have been found to be good target entrance windows for both low energy accelerators and medium energy cyclotrons. Detailed thermal analysis has given an approximate analytical expression for the maximum temperature reached in a foil window under conditions of realistic ion beam bombardment. The effects of 'hot spots' in the beam density profile were investigated. It was shown that a factor of two safety margin in window design should be adequate to compensate for any possible beam hot spots. In addition, the reduction of foil stress by slack mounting was verified by experiments. The properties of conventional and novel foil materials were investigated for use in conduction cooled windows. Novel foil materials include two-component Al/Ti and Al/Havar foil. Results on the testing of candidate foil materials for thermal conductivity and mechanical strength at elevated temperature were presented. Two optimum foil window geometries were analyzed: a high aspect ratio window and a multiply slotted window. The multiply slotted window combines the advantages of a high aspect ratio foil window with a circular beam strike and is a promising window design for both TCA and cyclotron targets. A multiply slotted window for a N 2 gas target for 15 O production was designed using the methodologies discussed above. This prototype target was successfully tested using the TCA beam at SRL. (author) 6 figs., 3 tabs., 10 refs

  1. 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.

  2. 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

  3. Surface roughening under ion bombardment

    International Nuclear Information System (INIS)

    Bhatia, C.S.

    1982-01-01

    Ion bombardment can cause roughening of a surface. Inadequate step coverage and poor adhesion of films on such surfaces are of concern. An extreme case of surface roughening results in cone formation under ion bombardment. The results of the investigation, using scanning electron microscopy, is discussed in terms of the role of (a) embedded particles, (b) impurities and (c) surface migration in cone formation on the target surface. (Auth.)

  4. 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

  5. Ion bombardment modification of surfaces

    International Nuclear Information System (INIS)

    Auciello, O.

    1984-01-01

    An historical overview of the main advances in the understanding of bombardment-induced surface topography is presented. The implantation and sputtering mechanisms which are relevant to ion bombardment modification of surfaces and consequent structural, electronic and compositional changes are described. Descriptions of plasma and ion-beam sputtering-induced film formation, primary ion-beam deposition, dual beam techniques, cluster of molecule ion-beam deposition, and modification of thin film properties by ion bombardment during deposition are presented. A detailed account is given of the analytical and computational modelling of topography from the viewpoint of first erosion theory. Finally, an account of the possible application and/or importance of textured surfaces in technologies and/or experimental techniques not considered in previous chapters is presented. refs.; figs.; tabs

  6. 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.

  7. 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.)

  8. 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.

  9. INSUL, Calculation of Thermal Insulation of Various Materials Immersed in He

    International Nuclear Information System (INIS)

    Kinkead, A.N.; Pitchford, B.E.

    1977-01-01

    1 - Nature of the physical problem solved: Performance of thermal insulation immersed in helium. 2 - Method of solution: Mineral fibre, metal fibre and metallic multi-layer foils are studied. An approximate analysis for performance evaluation of multi-layer insulation in vertical gas spaces including the regime between fully suppressed natural convection and that for which an accepted power relationship applies is included

  10. 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

  11. Actinide production in 136Xe bombardments of 249Cf

    International Nuclear Information System (INIS)

    Gregorich, K.E.

    1985-08-01

    The production cross sections for the actinide products from 136 Xe bombardments of 249 Cf at energies 1.02, 1.09, and 1.16 times the Coulomb barrier were determined. Fractions of the individual actinide elements were chemically separated from recoil catcher foils. The production cross sections of the actinide products were determined by measuring the radiations emitted from the nuclides within the chemical fractions. The chemical separation techniques used in this work are described in detail, and a description of the data analysis procedure is included. The actinide production cross section distributions from these 136 Xe + 249 Cf bombardments are compared with the production cross section distributions from other heavy ion bombardments of actinide targets, with emphasis on the comparison with the 136 Xe + 248 Cm reaction. A technique for modeling the final actinide cross section distributions has been developed and is presented. In this model, the initial (before deexcitation) cross section distribution with respect to the separation energy of a dinuclear complex and with respect to the Z of the target-like fragment is given by an empirical procedure. It is then assumed that the N/Z equilibration in the dinuclear complex occurs by the transfer of neutrons between the two participants in the dinuclear complex. The neutrons and the excitation energy are statistically distributed between the two fragments using a simple Fermi gas level density formalism. The resulting target-like fragment initial cross section distribution with respect to Z, N, and excitation energy is then allowed to deexcite by emission of neutrons in competition with fission. The result is a final cross section distribution with respect to Z and N for the actinide products. 68 refs., 33 figs., 6 tabs

  12. Ion bombardment modification of surfaces

    International Nuclear Information System (INIS)

    Auciello, O.

    1984-01-01

    Ion bombardment-induced modification of surfaces may be considered one of the significant scientific and technological developments of the last two decades. The understanding acquired concerning the underlying mechanisms of several phenomena occurring during ion-surface interactions has led to applications within different modern technologies. These include microelectronics, surface acoustical and optical technologies, solar energy conversion, thin film technology, ion implantation metallurgy, nuclear track technology, thermonuclear fusion, vacuum technology, cold welding technology, biomedicine (implantology). It has become clear that information on many relevant advances, regarding ion bombardment modification of surfaces is dispersed among journals involving fields sometimes not clearly related. This may result, in some cases, in a loss of the type of interdisciplinary exchange of ideas, which has proved to be so fruitful for the advancement of science and technology. This book has been planned in an attempt to collect at least some of today's relevant information about the experimental and theoretical knowledge related to surface modification and its application to technology. (Auth.)

  13. 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)

  14. Super-insulation

    International Nuclear Information System (INIS)

    Gerold, J.

    1985-01-01

    The invention concerns super-insulation, which also acts as spacing between two pressurized surfaces, where the crossing bars in at least two layers are provided, with interposed foil. The super-insulation is designed so that it can take compression forces and limits thermal radiation and thermal conduction sufficiently, where the total density of heat flow is usually limited to a few watts per m 2 . The solution to the problem is characterized by the fact that the bars per layer are parallel and from layer to layer they are at an angle to each other and the crossover positions of the bars of different layers are at fixed places and so form contact columns. The basic idea is that bars crossing over each other to support compression forces are used so that contact columns are formed, which are compressed to a certain extent by the load. (orig./PW) [de

  15. 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)

  16. Analytical model of heat transfer in porous insulation around cold pipes

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom; Karlsson, Per W.; Korsgaard, Vagn

    2011-01-01

    cloth is wrapped around the cold tube and extended through a slit in the tubular insulation and a slot in the facing to the ambient so that condensed water can evaporate into the air. Some of the moisture in that part of the wicking cloth situated in the slit in the tubular insulation will diffuse......A thermal insulation system is analysed that consists of a cold tube insulated with a porous material faced with a vapour retarding foil.Water vapour will diffuse through the vapour retarding foil and condense on the cold tube. To avoid build-up of water in the insulation a hydrophilic wicking...

  17. Handleable shapes of thermal insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J. T.

    1989-01-17

    Handleable and machineable shapes of thermal insulation material are made by compacting finely divided thermal insulation material into the cells of a reinforcing honeycomb insulation material into the cells of a reinforcing honeycomb structure. The finely divided thermal insulation material may be, for example, silica aerogel, pyrogenic silica, carbon black, silica gel, volatilised silica, calcium silicate, vermiculate or perlite, or finely divided metal oxides such as alumina or titania. The finely divided thermal insulation material may include an infra-red opacifier and/or reinforcing fibres. The reinforcing honeycomb structure may be made from, for example, metals such as aluminium foil, inorganic materials such as ceramics, organic materials such as plastics materials, woven fabrics or paper. A rigidiser may be employed. The shapes of thermal insulation material are substantially rigid and may be machines, for example by mechanical or laser cutting devices, or may be formed, for example by rolling, into curved or other shaped materials. 12 figs.

  18. Structural changes IN THE Kh20N45M4B nickel alloys and THE Kh16N15M3B steel due to helium ion bombardment

    International Nuclear Information System (INIS)

    Kalin, B.A.; Chernikov, U.N.; Chernov, I.I.; Kozhevnikov, O.A.; Shishkin, G.N.; Yakushin, V.L.

    1986-01-01

    Using transmission electron microscopy, x-ray structural analysis, and the thermal desorption techniques, the authors carried out a detailed study of the structural and phase changes, defect formation, and helium accumulation in the He + -bombarded 16-15 austenitic steels and 20-45 nickel alloys. Microstructure of the bombarded specimens was studied using the methods of transmission electron microscopy of thin foils in the EVM-100, and EM-301G electron microscopes. Results of x-ray studies on the bombarded specimens are presented. The conducted studies show that bombardment of structural materials with light ions can lead to significant structural damages and changes in the chemical and phase composition of the surface layer. The possible mechanisms of the changes in the chemical and phase composition include selective sputtering and radiation-induced accelerated diffusion of elements in the field of internal lateral stresses developing during the He + implantation process

  19. Field evaluation of reflective insulation in south east Asia

    Science.gov (United States)

    Teh, Khar San; Yarbrough, David W.; Lim, Chin Haw; Salleh, Elias

    2017-12-01

    The objective of this research was to obtain thermal performance data for reflective insulations in a South East Asia environment. Thermal resistance data (RSI, m2 ṡ K/W) for reflective insulations are well established from 1-D steady-state tests, but thermal data for reflective insulation in structures like those found in South East Asia are scarce. Data for reflective insulations in South East Asia will add to the worldwide database for this type of energy-conserving material. RSI were obtained from heat flux and temperature data of three identical structures in the same location. One unit did not have insulation above the ceiling, while the second and third units were insulated with reflective insulation with emittance less than 0.05. RSI for the uninsulated test unit varied from 0.37 to 0.40 m2 ṡ K/W. RSI for a single-sheet reflective insulation (woven foil) varied from 2.15 to 2.26 m2 ṡ K/W, while bubble-foil insulation varied from 2.69 to 3.09 m2 ṡ K/W. The range of RSI values resulted from differences in the spacing between the reflective insulation and the roof. In addition, the reflective insulation below the roof lowered attic temperatures by as much as 9.7° C. Reductions in ceiling heat flux of 80 to 90% relative to the uninsulated structure, due to the reflective insulation, were observed.

  20. 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.)

  1. 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

  2. Thermal insulation

    International Nuclear Information System (INIS)

    Aspden, G.J.; Howard, R.S.

    1988-01-01

    The patent concerns high temperature thermal insulation of large vessels, such as the primary vessel of a liquid metal cooled nuclear reactor. The thermal insulation consists of multilayered thermal insulation modules, and each module comprises a number of metal sheet layers sandwiched between a back and front plate. The layers are linked together by straps and clips to control the thickness of the module. (U.K.)

  3. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  4. 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

  5. The inaccuracy of heat transfer characteristics for non-insulated and insulated spherical containers neglecting the influence of heat radiation

    International Nuclear Information System (INIS)

    Wong, King-Leung; Salazar, Jose Luis Leon; Prasad, Leo; Chen, Wen-Lih

    2011-01-01

    In this investigation, the differences of heat transfer characteristics for insulated and non-insulated spherical containers between considering and neglecting the influence of heat radiation are studied by the simulations in some practical situations. It is found that the heat radiation effect cannot be ignored in conditions of low ambient convection heat coefficients (such ambient air) and high surface emissivities, especially for the non-insulated and thin insulated cases. In most practical situations when ambient temperature is different from surroundings temperature and the emissivity of insulation surface is different from that of metal wall surface, neglecting heat radiation will result in inaccurate insulation effect and heat transfer errors even with very thick insulation. However, the insulation effect considering heat radiation will only increase a very small amount after some dimensionless insulated thickness (such insulation thickness/radius ≥0.2 in this study), thus such dimensionless insulated thickness can be used as the optimum thickness in practical applications. Meanwhile, wrapping a material with low surface emissivity (such as aluminum foil) around the oxidized metal wall or insulation layer (always with high surface emissivity) can achieve very good insulated effect for the non-insulated or thin insulated containers.

  6. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

    Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

  7. Ion bombardment and disorder in amorphous silicon

    International Nuclear Information System (INIS)

    Sidhu, L.S.; Gaspari, F.; Zukotynski, S.

    1997-01-01

    The effect of ion bombardment during growth on the structural and optical properties of amorphous silicon are presented. Two series of films were deposited under electrically grounded and positively biased substrate conditions. The biased samples displayed lower growth rates and increased hydrogen content relative to grounded counterparts. The film structure was examined using Raman spectroscopy. The transverse optic like phonon band position was used as a parameter to characterize network order. Biased samples displayed an increased order of the amorphous network relative to grounded samples. Furthermore, biased samples exhibited a larger optical gap. These results are correlated and attributed to reduced ion bombardment effects

  8. 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

  9. Development and evolution of biaxial texture of rolled nickel tapes by ion beam bombardment for high Tc coated conductors

    International Nuclear Information System (INIS)

    Wang, S.S.; Wu, K.; Shi, K.; Liu, Q.; Han, Z.

    2004-01-01

    High quality YBa 2 Cu 3 O 7-x films on metallic substrates with high critical current densities well over 10 6 A/cm 2 can be prepared by the rolling assisted biaxially textured substrates (RABiTS) method. Nickel or its alloys have been used as biaxially textured substrates formed through a specific rolling and high temperature annealing procedures. In this paper, we report a newly developed process for developing biaxial texture in rolled Ni tape by argon ion beam bombardment. It is named the ion-beam structure modification (ISM) process. In the ISM processed Ni foils, X-ray diffraction ω scans showed the full width-half maximum (FWHM) value of the (2 0 0) peak was 5.7 deg. . And the electron back scattering diffraction (EBSP) analysis based on scanning electron microscopy showed good {1 0 0} cubic orientation and the mean grain size was determined as about 25 μm. The texture evolution of rolled Ni foils during ISM process is reported also. For ISM process, local temperature elevation and distribution arises from the ion bombardment, coupled with anisotropic incident ion penetration and propagation as a result of channeling effects in the metal lattice, are expected to play the major roles in the development of grain reorientation in the Ni foil. Due to the simplicity and efficiency of the ISM process, the technique shows a great promise for application in the industrial scale production of long-lengths of superconductor tapes

  10. Ion-beam bombardment induced texture in nickel substrates for coated high-Tc superconductors

    International Nuclear Information System (INIS)

    Wang, S S; Wu, K; Zhou, Y; Godfrey, A; Meng, J; Liu, M L; Liu, Q; Liu, W; Han, Z

    2003-01-01

    Biaxially textured metal substrates are often used for making YBa 2 Cu 3 O 7-x coated conductors with high critical current density. Generally, specific rolling and high-temperature annealing procedures are required to obtain the biaxial texture for metal substrates. Here, we report on a new method for developing strongly biaxially textured grain structure in rolled nickel tape by argon ion-beam bombardment. X-ray diffraction (XRD) θ-2θ scans have shown that a (200) diffraction peak intensity of the Ni foil processed by ion-beam structure modification (ISM) is two orders of magnitude greater than that of cold-rolled foil, while the (111) and (220) intensities are very weak. In the ISM processed Ni foils, from the rocking curve, the full width at half maximum (FWHM) value of the (200) peak has been found to be less than 5.9 deg., whilst the in-plane FWHM obtained from a pole figure analysis is just 8 deg. We discuss the possible mechanisms leading to the texture changes during ISM. (rapid communication)

  11. Experimental and theoretical studies of bombardment induced surface morphology changes

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.; Williams, J.S.

    1980-01-01

    In this review results of experimental and theoretical studies of solid surface morphology changes due to ion bombardment are discussed. An attempt is undertaken to classify the observed specific features of a structure, generated by ion bombardment [ru

  12. 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...

  13. Experimental and numerical study of heat transfer across insulation wall of a refrigerated integral panel van

    International Nuclear Information System (INIS)

    Glouannec, Patrick; Michel, Benoit; Delamarre, Guillaume; Grohens, Yves

    2014-01-01

    This paper presents an experimental and numerical design study of an insulation wall for refrigerated vans. The thermophysical properties of the insulating multilayer panel, the external environment impact (solar irradiation, temperature, etc.) and durability are taken into account. Different tools are used to characterize the thermal performances of the insulation walls and the thermal properties of the insulation materials are measured. In addition, an experiment at the wall scale is carried out and a 2D FEM model of heat and mass transfer within the wall is formulated. Three configurations are studied with this design approach. Multilayer insulation walls containing reflective multi-foil insulation, aerogel and phase change materials (PCM) are tested. Promising results are obtained with these materials, especially the reduction of peak heat transfer and energy consumption during the daytime period. Furthermore, the major influence of solar irradiation is highlighted as it can increase the peak heat transfer crossing the insulation wall by up to 43%. Nevertheless, we showed that the use of reflective multi-foil insulation and aerogel layers allowed decreasing this impact by 27%. - Highlights: • A design study of an insulation wall for a refrigerated van is carried out. • Experimental and numerical studies of multilayer insulation walls are performed. • The major influence of solar irradiation is highlighted. • New insulation materials (reflective multi-foil, aerogel and PCM) are tested

  14. Artificial heart system thermal insulation component development

    International Nuclear Information System (INIS)

    Svedberg, R.C.; Buckman, R.W. Jr.

    1975-01-01

    A concentric cup vacuum multifoil insulation system has been selected by virtue of its size, weight, and thermal performance to insulate the hot radioisotope portion of the thermal converter of an artificial implantable heart system. A factor of 2 improvement in thermal performance, based on the heat loss per number of foil layers (minimum system weight and volume) has been realized over conventional spiral wrapped multifoil vacuum insulation. This improvement is the result of the concentric cup construction to maintain a uniform interfoil spacing and the elimination of corner heat losses. Based on external insulation system dimensions (surface area in contact with host body), heat losses of 0.019 W/ cm 2 at 1140 0 K (1600 0 F) and 0.006 W/cm 2 at 920 0 K (1200 0 F) have been achieved. Factors which influence thermal performance of the nickel foil concentric cup insulation system include the number of cups, configuration and method of application of zirconia (ZrO 2 ) spacer material, system pressure, emittance of the cups, and operating temperature

  15. Metallic insulation transport and strainer clogging tests

    International Nuclear Information System (INIS)

    Hyvaerinen, J.; Hongisto, O.

    1994-06-01

    Experiments to probe the transport and clogging properties of metallic (metal reflective) insulation have been carried out in order to provide data for evaluation of their influence on the emergency core cooling and containment spray systems of the Finnish boiling water reactors in the event of a design basis accident. The specific metallic insulation tested was DARMET, provided by Darchem Engineering Ltd. The inner foils of Darmet are dimped. Available literature on the metallic insulation performance under design basis accident conditions has been reviewed. On the basis of the review a parametric approach has been chosen for the transport and clogging experiments. This approach involves testing a wide size range of various shapes of foil pieces. Five sets of experiments have been carried out. The first three sets investigate transport properties of the foil pieces, starting from sedimentation in stagnant waste pool and proceeding to transport in horizontal and vertically circulating flows. The clogging experiments have been addressed the differential pressures obtained due to accumulation of both pure and metallic and a mixture of metallic and fibrous (mineral wool) depris. (4 refs., 24 figs., 2 tabs.)

  16. Magnetoresistance and ion bombardment induced magnetic patterning

    International Nuclear Information System (INIS)

    Hoeink, V.

    2008-01-01

    In this thesis the combination of the magnetic patterning of the unidirectional anisotropy and the tunnel magnetoresistance effect is investigated. In my diploma thesis, it has been shown that it is in principle possible to use the magnetic patterning by ion bombardment to magnetically structure the pinned layer in magnetic tunnel junctions (MTJs) with alumina barrier. Furthermore, it has been shown that the side effects which have been observed after this treatment can be at least reduced by an additional heating step. Starting from this point, the applicability of ion bombardment induced magnetic patterning (IBMP) in general and the combination of IBMP and MTJs in particular is investigated and new applications are developed. (orig.)

  17. Modification of thin film properties by ion bombardment during deposition

    International Nuclear Information System (INIS)

    Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

    1984-01-01

    Many thin film deposition techniques involve some form of energetic particle bombardment of the growing film. The degree of bombardment greatly influences the film composition, structure and other properties. While in some techniques the degree of bombardment is secondary to the original process design, in recent years more deposition systems are being designed with the capability for controlled ion bombardment of thin films during deposition. The highest degree of control is obtained with ion beam sources which operate independently of the vapor source providing the thin film material. Other plasma techniques offer varying degrees of control of energetic particle bombardment. Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. (Auth.)

  18. 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

  19. Thermal insulation

    International Nuclear Information System (INIS)

    Durston, J.G.; Birch, W.; Facer, R.I.; Stuart, R.A.

    1977-01-01

    Reference is made to liquid metal cooled nuclear reactors. In the arrangement described the reactor vessel is clad with thermal insulation comprising a layer of insulating blocks spaced from the wall and from each other; each block is rigidly secured to the wall, and the interspaces are substantially closed against convectional flow of liquid by resilient closure members. A membrane covering is provided for the layer of blocks, with venting means to allow liquid from the reactor vessel to penetrate between the covering and the layer of blocks. The membrane covering may comprise a stainless steel sheet ribbed in orthogonal pattern to give flexibility for the accommodation of thermal strain. The insulating blocks may be comprised of stainless steel or cellular or porous material and may be hollow shells containing ceramic material or gas fillings. (U.K.)

  20. Topological insulators

    CERN Document Server

    Franz, Marcel

    2013-01-01

    Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was

  1. Secondary electron emission from insulators

    International Nuclear Information System (INIS)

    Kanaya, K.; Ono, S.; Ishigaki, F.

    1978-01-01

    The high yield of secondary electron emission from insulators due to electron bombardment may be the result of an increase of the depth of escape. The free-electron scattering theory is applied to the high energy of primary beams, but cannot be applied to the low energy of secondary escaping beams because of the large energy gap of the insulators. The plasmon loss with the valence electron is considered when the secondary electrons escape. Based on the energy retardation power formula of the penetration and energy loss of an electron probe into solid targets, secondary electron emissions from insulators are calculated from the assumptions that the distribution of the secondary electrons due to both incident and back-scattered electrons within the target is isotropic and that it follows the absorption law of the Lenard type. The universal yield-energy curve of the secondary electron emission, which is deduced as a function of three parameters such as ionisation potential, valence electron and the back-scattered coefficient in addition to the free-electron density effect, is found to be in good agreement with the experimental results. (author)

  2. 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)

  3. 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.

  4. Beryllium dust generation resulting from plasma bombardment

    International Nuclear Information System (INIS)

    Doerner, R.; Mays, C.

    1997-01-01

    The beryllium dust resulting from erosion of beryllium samples subjected to plasma bombardment has been measured in PISCES-B. Loose surface dust was found to be uniformly distributed throughout the device and accounts for 3% of the eroded material. A size distribution measurement of the loose surface dust shows an increasing number of particles with decreasing diameter. Beryllium coatings on surfaces with a line of sight view of the target interaction region account for an additional 33% of the eroded beryllium material. Flaking of these surface layers is observed and is thought to play a significant role in dust generation inside the vacuum vessel. (orig.)

  5. Electron emission from Inconel under ion bombardment

    International Nuclear Information System (INIS)

    Alonso, E.V.; Baragiola, R.A.; Ferron, J.; Oliva-Florio, A.

    1979-01-01

    Electron yields from clean and oxidized Inconel 625 surfaces have been measured for H + ,H 2 + ,He + ,O + and Ar + ions at normal incidence in the energy range 1.5 to 40 keV. These measurements have been made under ultrahigh vacuum and the samples were freed of surface contaminants by bombarding with high doses of either 20 keV H 2 + or 30 keV Ar + ions. Differences in yields of oxidized versus clean surfaces are explained in terms of differences in the probability that electrons internally excited escape upon reaching the surface. (author)

  6. 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

  7. Modification of thin film properties by ion bombardment during deposition

    International Nuclear Information System (INIS)

    Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

    1984-01-01

    Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. Examples of thin film property modification by ion bombardment during deposition, including effects which are primarily compositional as well as those which are primarily structural are presented. The examples demonstrate the usefulness of ion beam techniques in identifying and controlling the fundamental deposition parameters. 68 refs.; 15 figs.; 1 table

  8. Electrical insulator assembly with oxygen permeation barrier

    Science.gov (United States)

    Van Der Beck, Roland R.; Bond, James A.

    1994-01-01

    A high-voltage electrical insulator (21) for electrically insulating a thermoelectric module (17) in a spacecraft from a niobium-1% zirconium alloy wall (11) of a heat exchanger (13) filled with liquid lithium (16) while providing good thermal conductivity between the heat exchanger and the thermoelectric module. The insulator (21) has a single crystal alumina layer (SxAl.sub.2 O.sub.3, sapphire) with a niobium foil layer (32) bonded thereto on the surface of the alumina crystal (26) facing the heat exchanger wall (11), and a molybdenum layer (31) bonded to the niobium layer (32) to act as an oxygen permeation barrier to preclude the oxygen depleting effects of the lithium from causing undesirable niobium-aluminum intermetallic layers near the alumina-niobium interface.

  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. Transport and screen blockage characteristics of reflective metallic insulation materials

    International Nuclear Information System (INIS)

    Brocard, D.N.

    1984-01-01

    In the event of a LOCA within a nuclear power plant, it is possible for insulation debris to be generated by the break jet. Such debris has the potential for PWR sump screen (or BWR RHR suction inlet) blockage and thus can affect the long-term recirculation capability. In addition to the variables of break jet location and orientation, the types and quantities of debris which could be generated are dependent on the insulation materials employed. This experimental investigation was limited to reflective metallic insulation and components thereof. The study was aimed at determining the flow velocities needed to transport the insulation debris to the sump screens and the resulting modes of screen blockage. The tests revealed that thin metallic foils (0.0025 in. and 0.004 in.) could transport at low flow velocities, 0.2 to 0.5 ft/sec. Thicker foils (0.008 in.) transported at higher velocities, 0.4 to 0.8 ft/sec, and as fabricated half cylinder insulation units required velocities in excess of 1.0 ft/sec for transport. The tests also provided information on screen blockage patterns that showed blockage could occur at the lower portion of the screen as foils readily flipped on the screen when reaching it

  11. Adhesion of silver films to ion-bombarded alumina

    International Nuclear Information System (INIS)

    Erck, R.A.; Fenske, G.R.

    1990-01-01

    This paper reports on silver films deposited on alumina substrates using ion bombardment. Adhesion strength was measured as a function of deposition conditions, sputter-cleaning time, and bombarding ion species, using a pull-type adhesion tester. Argon- and argon/oxygen-ion sputtering produced large increases in adhesion strength, with the greatest increases occurring for oxygen-ion bombardment. Adhesion strength increased monotonically as a function of ion sputtering time. At a given deposition rate, further enhancement of adhesion is seen with concurrent ion bombardment

  12. Investigation of Insulation Materials for Future Radioisotope Power Systems

    Science.gov (United States)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Technology Advancement Project is developing next generation high-temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  13. Investigation of Insulation Materials for Future Radioisotope Power Systems (RPS)

    Science.gov (United States)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power System (RPS) Technology Advancement Project is developing next generation high temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center (GRC) on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  14. 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.

  15. 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

  16. The timeline of the lunar bombardment: Revisited

    Science.gov (United States)

    Morbidelli, A.; Nesvorny, D.; Laurenz, V.; Marchi, S.; Rubie, D. C.; Elkins-Tanton, L.; Wieczorek, M.; Jacobson, S.

    2018-05-01

    The timeline of the lunar bombardment in the first Gy of Solar System history remains unclear. Basin-forming impacts (e.g. Imbrium, Orientale), occurred 3.9-3.7 Gy ago, i.e. 600-800 My after the formation of the Moon itself. Many other basins formed before Imbrium, but their exact ages are not precisely known. There is an intense debate between two possible interpretations of the data: in the cataclysm scenario there was a surge in the impact rate approximately at the time of Imbrium formation, while in the accretion tail scenario the lunar bombardment declined since the era of planet formation and the latest basins formed in its tail-end. Here, we revisit the work of Morbidelli et al. (2012) that examined which scenario could be compatible with both the lunar crater record in the 3-4 Gy period and the abundance of highly siderophile elements (HSE) in the lunar mantle. We use updated numerical simulations of the fluxes of asteroids, comets and planetesimals leftover from the planet-formation process. Under the traditional assumption that the HSEs track the total amount of material accreted by the Moon since its formation, we conclude that only the cataclysm scenario can explain the data. The cataclysm should have started ∼ 3.95 Gy ago. However we also consider the possibility that HSEs are sequestered from the mantle of a planet during magma ocean crystallization, due to iron sulfide exsolution (O'Neil, 1991; Rubie et al., 2016). We show that this is likely true also for the Moon, if mantle overturn is taken into account. Based on the hypothesis that the lunar magma ocean crystallized about 100-150 My after Moon formation (Elkins-Tanton et al., 2011), and therefore that HSEs accumulated in the lunar mantle only after this timespan, we show that the bombardment in the 3-4 Gy period can be explained in the accretion tail scenario. This hypothesis would also explain why the Moon appears so depleted in HSEs relative to the Earth. We also extend our analysis of the

  17. 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.

  18. 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

  19. 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).

  20. 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

  1. 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.

  2. Handbook of Thermal Insulation Applications.

    Science.gov (United States)

    1983-01-01

    Wiuppuoror *tIe beamsWiefag ln~ td ~oair ilmstool beams Plate 18. Metal Building Ceilings - A 18b: Fir* hataird rathge may limit the use of foam Insulation...RFCTANGUI.AR SOL TD A = 2(WxL+LxH+HxW) B V = WxLxH H L TRAPEZOID A 2 (A + B) x H A CONE A -n xRxS+ i xR 2 B V =( /3)x R2 x H TRIANGLE A BxH A- 2 CYLI NDER H 2...FABRICATIIG RECTANGULAR HEATING AND COOLING DUCTWORK. FIBERGLAS DUCT BOARD OWENS-CORNING FIBERGLAS CORP GLASS FIBER RIGID BOARD WITH ALUMINUM 4bD FOIL VAPOR

  3. Electron emission from molybdenum under ion bombardment

    International Nuclear Information System (INIS)

    Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

    1981-01-01

    Measurements are reported of electron emission yields of clean molybdenum surfaces under bombardment with H + , H 2 + , D + , D 2 + , He + , N + , N 2 + , O + , O 2 + , Ne + , Ar + , Kr + and Xe + in the wide energy range 0.7-60.2 keV. The clean surfaces were produced by inert gas sputtering under ultrahigh vacuum. The results are compared with those predicted by a core-level excitation model. The disagreement found when using correct values for the energy levels of Mo is traced to wrong assumptions in the model. A substantially improved agreement with experiment is obtained using a model in which electron emission results from the excitation of valence electrons from the target by the projectiles and fast recoiling target atoms. (author)

  4. Ion bombardment techniques - recent developments in SIMS

    International Nuclear Information System (INIS)

    Konarski, P.; Miśnik, M.

    2013-01-01

    We present a short review of cluster ion bombardment technique recently applied in SIMS. Many advantages of using cluster ion beams are specified over monoatomic ion species. Cluster ions open really new perspectives especially in organic based structures analysis. Nevertheless cluster ions are not the perfect solution and still new ideas of ion erosion in SIMS are needed. Another issue discussed is 'storing matter' technique applied for quantitative analysis in SIMS. Simple idea of sputter deposition of eroded material onto rotating substrate and then analysing the stored material allows to avoid strong matrix effects in SIMS. Presented are the results performed in Tele and Radio Research Institute, Warszawa, Poland. These are the first results of ‘storing matter’ technique performed in one analytical chamber of SIMS instrument. (authors)

  5. The terrestrial record of Late Heavy Bombardment

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.

    2018-04-01

    Until recently, the known impact record of the early Solar System lay exclusively on the surfaces of the Moon, Mars, and other bodies where it has not been erased by later weathering, erosion, impact gardening, and/or tectonism. Study of the cratered surfaces of these bodies led to the concept of the Late Heavy Bombardment (LHB), an interval from about 4.1 to 3.8 billion years ago (Ga) during which the surfaces of the planets and moons in the inner Solar System were subject to unusually high rates of bombardment followed by a decline to present low impact rates by about 3.5 Ga. Over the past 30 years, however, it has become apparent that there is a terrestrial record of large impacts from at least 3.47 to 3.22 Ga and from 2.63 to 2.49 Ga. The present paper explores the earlier of these impact records, providing details about the nature of the 8 known ejecta layers that constitute the evidence for large terrestrial impacts during the earlier of these intervals, the inferred size of the impactors, and the potential effects of these impacts on crustal development and life. The existence of this record implies that LHB did not end abruptly at 3.8-3.7 Ga but rather that high impact rates, either continuous or as impact clusters, persisted until at least the close of the Archean at 2.5 Ga. It implies that the shift from external, impact-related controls on the long-term development of the surface system on the Earth to more internal, geodynamic controls may have occurred much later in geologic history than has been supposed previously.

  6. Cesium ion bombardment of metal surfaces

    International Nuclear Information System (INIS)

    Tompa, G.S.

    1986-01-01

    The steady state cesium coverage due to cesium ion bombardment of molybdenum and tungsten was studied for the incident energy range below 500 eV. When a sample is exposed to a positive ion beam, the work function decreases until steady state is reached with a total dose of less than ≅10 16 ions/cm 2 , for both tungsten and molybdenum. A steady state minimum work function surface is produced at an incident energy of ≅100 eV for molybdenum and at an incident energy of ≅45 eV for tungsten. Increasing the incident energy results in an increase in the work function corresponding to a decrease in the surface coverage of cesium. At incident energies less than that giving the minimum work function, the work function approaches that of cesium metal. At a given bombarding energy the cesium coverage of tungsten is uniformly less than that of molybdenum. Effects of hydrogen gas coadsorption were also examined. Hydrogen coadsorption does not have a large effect on the steady state work functions. The largest shifts in the work function due to the coadsorption of hydrogen occur on the samples when there is no cesium present. A theory describing the steady-state coverage was developed is used to make predictions for other materials. A simple sticking and sputtering relationship, not including implantation, cannot account for the steady state coverage. At low concentrations, cesium coverage of a target is proportional to the ratio of (1 - β)/γ where β is the reflection coefficient and γ is the sputter yield. High coverages are produced on molybdenum due to implantation and low backscattering, because molybdenum is lighter than cesium. For tungsten the high backscattering and low implantation result in low coverages

  7. Cleaning of diffusion bonding surface by argon ion bombardment treatment

    International Nuclear Information System (INIS)

    Wang, Airu; Ohashi, Osamu; Yamaguchi, Norio; Aoki, Masanori; Higashi, Yasuo; Hitomi, Nobuteru

    2003-01-01

    The specimens of oxygen-free high conductivity copper, SUS304L stainless steel and pure iron were treated by argon ion bombardment and then were bonded by diffusion bonding method. The effects of argon ion bombardment treatment on faying surface morphology, tensile strength of bonding joints and inclusions at the fracture surface were investigated. The results showed that argon ion bombardment treatment was effective to remove the oxide film and contamination at the faying surface and improve the quality of joints. The tensile strength of the bonded joints was improved, and minimum bonding temperature to make the metallic bonding at the interface was lowered by argon ion bombardment treatment. At the joints with argon ion bombardment treatment, ductile fractured surface was seen and the amount of inclusions was obviously decreased

  8. Tank Insulation

    Science.gov (United States)

    1979-01-01

    For NASA's Apollo program, McDonnell Douglas Astronautics Company, Huntington Beach, California, developed and built the S-IVB, uppermost stage of the three-stage Saturn V moonbooster. An important part of the development task was fabrication of a tank to contain liquid hydrogen fuel for the stage's rocket engine. The liquid hydrogen had to be contained at the supercold temperature of 423 degrees below zero Fahrenheit. The tank had to be perfectly insulated to keep engine or solar heat from reaching the fuel; if the hydrogen were permitted to warm up, it would have boiled off, or converted to gaseous form, reducing the amount of fuel available to the engine. McDonnell Douglas' answer was a supereffective insulation called 3D, which consisted of a one-inch thickness of polyurethane foam reinforced in three dimensions with fiberglass threads. Over a 13-year development and construction period, the company built 30 tanks and never experienced a failure. Now, after years of additional development, an advanced version of 3D is finding application as part of a containment system for transporting Liquefied Natural Gas (LNG) by ship.

  9. On results of tests of thermal insulation structural fragments for in-vessel equipment and pipelines of the VG-400 plant on vibrational and acoustic loads

    International Nuclear Information System (INIS)

    Ledenko, S.A.; Andreev, V.A.; Mirenkov, A.F.; Zakharov, V.A.; Suvorov, V.E.; Prokimnov, V.V.

    1990-01-01

    Results of vibrostrength and acoustic fatigue tests of the fragments of thermal insulation for in-vessel equipment and pipelines of the VG-400 reactor are presented. The insulation structure is based on the insulation layer made of steel foil and carbon materials. Weak points in the insulation structure, namely - the welded joints of stiffening ribs - are detected in the course of testing. A conclusion is made on the possibility of vibrational test substitution for the acoustic ones

  10. 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

  11. Influence of ion bombardment on structural and electrical properties of SiO2 thin films deposited from O2/HMDSO inductively coupled plasmas under continuous wave and pulsed modes

    International Nuclear Information System (INIS)

    Bousquet, A.; Goullet, A.; Leteinturier, C.; Granier, A.; Coulon, N.

    2008-01-01

    Low pressure Plasma Enhanced Chemical Vapour Deposition is commonly used to deposit insulators on temperature sensitive substrates. In these processes, the ion bombardment experienced by films during its growth is known to have benefits but also some disadvantages on material properties. In the present paper, we investigate the influence of this bombardment on the structure and the electrical properties of SiO 2 -like film deposited from oxygen/hexa-methyl-di-siloxane radiofrequency plasma in continuous and pulsed modes. First, we studied the ion kinetics thanks to time-resolved measurements by Langmuir probe. After, we showed the ion bombardment in such plasma controls the OH bond content in deposited films. Finally, we highlight the impressive reduction of fixed charge and interface state densities in films obtained in pulsed mode due to a lower ion bombardment. (authors)

  12. 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.

  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. 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.

  15. Ultra-thin smart acoustic metasurface for low-frequency sound insulation

    Science.gov (United States)

    Zhang, Hao; Xiao, Yong; Wen, Jihong; Yu, Dianlong; Wen, Xisen

    2016-04-01

    Insulating low-frequency sound is a conventional challenge due to the high areal mass required by mass law. In this letter, we propose a smart acoustic metasurface consisting of an ultra-thin aluminum foil bonded with piezoelectric resonators. Numerical and experimental results show that the metasurface can break the conventional mass law of sound insulation by 30 dB in the low frequency regime (sound insulation performance is attributed to the infinite effective dynamic mass density produced by the smart resonators. It is also demonstrated that the excellent sound insulation property can be conveniently tuned by simply adjusting the external circuits instead of modifying the structure of the metasurface.

  16. Modification of Polymer Materials by Ion Bombardment: Case Studies

    International Nuclear Information System (INIS)

    Bielinski, D. M.; Jagielski, J.; Lipinski, P.; Pieczynska, D.; Ostaszewska, U.; Piatkowska, A.

    2009-01-01

    The paper discusses possibility of application of ion beam bombardment for modification of polymers. Changes to composition, structure and morphology of the surface layer produced by the treatment and their influence on engineering and functional properties of wide range of polymer materials are presented. Special attention has been devoted to modification of tribological properties. Ion bombardment results in significant reduction of friction, which can be explained by increase of hardness and wettability of polymer materials. Hard but thin enough skin does not result in cracking but improves their abrasion resistance. Contrary to conventional chemical treatment ion beam bombardment works even for polymers hardly susceptible to modification like silicone rubber or polyolefines.

  17. 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.

  18. 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

  19. 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).

  20. 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.

  1. Scanning electron microscope investigations of nuclear pore filters in polyester foils

    International Nuclear Information System (INIS)

    Hopfe, J.

    1980-01-01

    In order to understand and characterize the action of nuclear pore filters it is necessary to know their surface, as well as their bulk, structure. In the present work, investigations of the surface structure (pore size, pore density, pore distribution) and of the pore geometry, especially in the bulk of the filters, are carried out by scanning electron microscopic (SEM) studies. The preparation technique needed is liquid-nitrogen freeze-fracturing followed by a conductive-coating step. Nuclear pore filters studied in this paper were produced by a track etching technique. Laboratory specimens were obtained by bombarding 10 μm thick polyester foils with Xe-ions and a subsequent etching with 20% NaOH. The SEM results are shown and discussed. (author)

  2. Neutron spectrum determination of d(20)+Be source reaction by the dosimetry foils method

    Science.gov (United States)

    Stefanik, Milan; Bem, Pavel; Majerle, Mitja; Novak, Jan; Simeckova, Eva

    2017-11-01

    The cyclotron-based fast neutron generator with the thick beryllium target operated at the NPI Rez Fast Neutron Facility is primarily designed for the fast neutron production in the p+Be source reaction at 35 MeV. Besides the proton beam, the isochronous cyclotron U-120M at the NPI provides the deuterons in the energy range of 10-20 MeV. The experiments for neutron field investigation from the deuteron bombardment of thick beryllium target at 20 MeV were performed just recently. For the neutron spectrum measurement of the d(20)+Be source reaction, the dosimetry foils activation method was utilized. Neutron spectrum reconstruction from resulting reaction rates was performed using the SAND-II unfolding code and neutron cross-sections from the EAF-2010 nuclear data library. Obtained high-flux white neutron field from the d(20)+Be source is useful for the intensive irradiation experiments and cross-section data validation.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. 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.))

  13. 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

  14. Impact and spreading behavior of cluster atoms bombarding substrates

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Te-Hua, E-mail: fang.tehua@msa.hinet.net [Institute of Mechanical and Electromechanical Engineering, National Formosa University, Yunlin 632, Taiwan (China); Kang, Shao-Hui; Liao, Jia-Hung [Institute of Mechanical and Electromechanical Engineering, National Formosa University, Yunlin 632, Taiwan (China)

    2009-12-15

    The purpose of this study is to investigate the behavior of copper cluster atoms bombarding a substrate using molecule dynamics based on tight-binding second moment approximation (TB-SMA) potential. The simulated results show that a crater on the substrate surface was created by the impact of the clusters. The variations of kinetic energy of cluster bombardments can be divided into three stages. At the initial impact level, the kinetic energies of the clusters and the substrate were constant. Then, the system went into a sluggish stage of energy variation, in which the kinetic energy of the clusters reduced. In the final stage, the kinetic energy of the system became stable. The high slip vector region around the crater had a disorder damage zone. The symmetry-like cross-slip occurred beneath the top layer of the substrate along the <1 1 0> orientations. The spreading index, temperature, and potential functions that affect the bombardments are also discussed.

  15. Impact and spreading behavior of cluster atoms bombarding substrates

    International Nuclear Information System (INIS)

    Fang, Te-Hua; Kang, Shao-Hui; Liao, Jia-Hung

    2009-01-01

    The purpose of this study is to investigate the behavior of copper cluster atoms bombarding a substrate using molecule dynamics based on tight-binding second moment approximation (TB-SMA) potential. The simulated results show that a crater on the substrate surface was created by the impact of the clusters. The variations of kinetic energy of cluster bombardments can be divided into three stages. At the initial impact level, the kinetic energies of the clusters and the substrate were constant. Then, the system went into a sluggish stage of energy variation, in which the kinetic energy of the clusters reduced. In the final stage, the kinetic energy of the system became stable. The high slip vector region around the crater had a disorder damage zone. The symmetry-like cross-slip occurred beneath the top layer of the substrate along the orientations. The spreading index, temperature, and potential functions that affect the bombardments are also discussed.

  16. Destruction of C60 films by boron ion bombardment

    International Nuclear Information System (INIS)

    Ren Zhongmin; Du Yuancheng; Ying Zhifeng; Xiong Xiaxing; Li Fuming

    1995-01-01

    C 60 films are bombarded by 100 keV boron ion beams at doses ranging from 3x10 14 to 1x10 16 /cm 2 . The bombarded films are analyzed using Fourier transform infrared spectroscopy (FTIR), Raman spectra and X-ray diffraction (XRD) measurements. Most C 60 soccer-balls in the implanted region in the films are found to be broken at a dose over 1x10 15 /cm 2 , while at a dose less than 6x10 14 /cm 2 a few C 60 molecules remain undestroyed and maintain some crystal structure. The results of the analyses suggest a complete disintegration of a C 60 molecule under B + bombardment. ((orig.))

  17. Catalytic oxidation of silicon by cesium ion bombardment

    International Nuclear Information System (INIS)

    Souzis, A.E.; Huang, H.; Carr, W.E.; Seidl, M.

    1991-01-01

    Results for room-temperature oxidation of silicon using cesium ion bombardment and low oxygen exposure are presented. Bombardment with cesium ions is shown to allow oxidation at O 2 pressures orders of magnitude smaller than with noble gas ion bombardment. Oxide layers of up to 30 A in thickness are grown with beam energies ranging from 20--2000 eV, O 2 pressures from 10 -9 to 10 -6 Torr, and total O 2 exposures of 10 0 to 10 4 L. Results are shown to be consistent with models indicating that initial oxidation of silicon is via dissociative chemisorption of O 2 , and that the low work function of the cesium- and oxygen-coated silicon plays the primary role in promoting the oxidation process

  18. 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,…

  19. 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.

  20. 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...

  1. Economically optimal thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    Berber, J.

    1978-10-01

    Exemplary calculations to show that exact adherence to the demands of the thermal insulation ordinance does not lead to an optimal solution with regard to economics. This is independent of the mode of financing. Optimal thermal insulation exceeds the values given in the thermal insulation ordinance.

  2. 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.

  3. 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.

  4. 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.

  5. 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.)

  6. Adhesion of evaporated titanium films to ion-bombarded polyethylene

    International Nuclear Information System (INIS)

    Bodoe, P.; Sundgren, J.

    1986-01-01

    Ti films were deposited onto high-density polyethylene (HDPE) samples by electron-beam evaporation. Prior to film deposition the samples were in situ pretreated by Ar ion bombardment using a sputter ion gun. The adhesion of the films, determined as the pull strength required for film failure, was measured as a function of ion dose. HDPE substrates processed at two different temperatures were examined. The adhesion of the Ti films to HDPE samples processed at roughly-equal150 0 C increased with the ion dose to a steady-state value corresponding to the cohesive strength of the HDPE substrate. The adhesion to the samples processed at roughly-equal200 0 C increased to a maximum and then decreased for further ion bombardment to a level of the same order as that for films deposited onto as-prepared samples. The effects of the ion bombardment upon the HDPE surface chemistry were examined by means of x-ray photoelectron spectroscopy (XPS). The ion bombardment resulted in dehydrogenation and cross linking of the surface region and for prolonged ion bombardment, a graphitelike surface was obtained. The film/substrate interface as well as the initial Ti film growth were examined by XPS analysis. A chemical interaction which resulted in Ti--C bonds was observed at the interface. The Ti film growth followed a pronounced three-dimensional growth mode on as-prepared surfaces whereas the ion bombardment resulted in a change toward a more two-dimensional growth mode. The difference in adhesion behavior for the two types of HDPE substrates was found to be due to a difference in the amounts of low molecular weight products present within the substrates

  7. 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

  8. Ion bombardment induced ripple topography on amorphous solids

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.; Paton, F.; Williams, J.S.

    1977-01-01

    Earlier studies of the ion bombardment induced ripple morphology on the surfaces of amorphous solids when compared with geomorphological effects are shown to possess many similar features. The present study, with 40 keV Ar + ion bombarded Si suggests that analogies are incomplete, however, and that greater similarities with the process of macroscopic sandblasting (corrosion) exist. It is shown that the genesis of wave like structures on Si is from isolated features, which have the appearance of ripple trains, which are faceted. It is suggested that these features result from particle flux enhancement processes near surface dimples generated by stress induced surface lifting. (author)

  9. Computer simulation of the topography evolution on ion bombarded surfaces

    CERN Document Server

    Zier, M

    2003-01-01

    The development of roughness on ion bombarded surfaces (facets, ripples) on single crystalline and amorphous homogeneous solids plays an important role for example in depth profiling techniques. To verify a faceting mechanism based not only on sputtering by directly impinging ions but also on the contribution of reflected ions and the redeposition of sputtered material a computer simulation has been carried out. The surface in this model is treated as a two-dimensional line segment profile. The model describes the topography evolution on ion bombarded surfaces including the growth mechanism of a facetted surface, using only the interplay of reflected and primary ions and redeposited atoms.

  10. 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.

  11. Thermal insulating panel

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.T.

    1985-09-11

    A panel of thermal insulation material has at least one main portion which comprises a dry particulate insulation material compressed within a porous envelope so that it is rigid or substantially rigid and at least one auxiliary portion which is secured to and extends along at least one of the edges of the main portions. The auxiliary portions comprise a substantially uncompressed dry particulate insulation material contained within an envelope. The insulation material of the auxiliary portion may be the same as or may be different from the insulation material of the main portion. The envelope of the auxiliary portion may be made of a porous or a non-porous material. (author).

  12. Barrier effect of AlN film in flexible Cu(In,Ga)Se{sub 2} solar cells on stainless steel foil and solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Li, Boyan; Li, Jianjun [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Wu, Li [The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin 300071 (China); Liu, Wei; Sun, Yun [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China); Zhang, Yi, E-mail: yizhang@nankai.edu.cn [Institute of Photo-electronic Thin Film Devices and Technology, Key Laboratory of Photo-electronic Thin Film Devices and Technology of Tianjin, Nankai University, Tianjin 300071 (China)

    2015-04-05

    Highlights: • The adhension between AlN film and Mo are verygood. • AlN film can be effectively used as the barrier of flexible CIGS solar cell on SS substrate. • AlN film is suitable as the insulation barrier of flexible CIGS solar cell on SS substrate. - Abstract: The AlN film deposited by DC magnetron sputtering on stainless steel (SS) foils was used as the barrier in flexible Cu(In,Ga)Se{sub 2} (CIGS) solar cells on stainless steel foil and characterized comprehensively by X-ray diffraction (XRD), scanning electron microscopy (SEM), I–V, and QE measurements study. The study of AlN as insulation barrier in the flexible CIGS solar cell showed that the adhesion strength between the SS foil and the deposited AlN film was very strong even after annealing at high temperature at 530 °C. More importantly, a high resistance of over 10 MΩ was remained with the film with thickness of around 200 nm after annealing. This indicates that the AlN film is suitable as an effective insulation barrier in flexible CIGS solar cells based on SS foil. In addition, the XRD and SEM results showed that the AlN film did not influence the crystal structure of the Mo film which was deposited upon the AlN layer and used as the electrical contact in CIGS solar cells. It was found that the AlN film contributed to an improved crystallinity of the Mo contact layer compared to the bare SS foil. The combined results of secondary ion mass spectrometry, I–V and EQE measurements of the corresponding flexible CIGS solar cells confirmed that 1 μm-thick AlN film could be used as an efficient barrier layer in CIGS solar cells on SS foil.

  13. Multi-layered foil capture of micrometeoroids and orbital debris in low Earth orbit

    Science.gov (United States)

    Kearsley, A.; Graham, G.

    Much of our knowledge concerning the sub-millimetre orbital debris population that poses a threat to orbiting satellites has been gleaned from examination of surfaces retrieved and subsequently analysed as part of post-flight investigations. The preservation of the hypervelocity impact-derived remnants located on these surfaces is very variable, whether of space debris or micrometeoroid origin. Whilst glass and metallic materials show highly visible impact craters when examined using optical and electron microscopes, complex mixing between the target material and the impacting particle may make unambiguous interpretation of the impactor origin difficult or impossible. Our recent detailed examination of selected multi-layered insulation (MLI) foils from the ISAS Space Flyer Unit (SFU), and our preliminary study of NASA's Trek blanket, exposed on the Mir station, show that these constructions have the potential to preserve abundant residue material of a quality sufficient for detailed analysis. Although there are still limitations on the recognition of certain sources of orbital debris, the foils complement the metal and glass substrates. We suggest that a purpose-built multi-layered foil structure may prove to be extremely effective for rapid collection and unambiguous analysis of impact- derived residues. Such a collector could be used an environmental monitor for ISS, as it would have low mass, high durability, easy deployment, recovery and storage, making it an economically viable and attractive option.

  14. 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)

  15. 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

  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. Extraction magnetically insulated diode studies on Gamble II

    International Nuclear Information System (INIS)

    Neri, J.M.; Boller, J.R.; Ottinger, P.F.; Stephanakis, S.J.; Greenly, J.

    1993-01-01

    An extraction Magnetically Insulated Diode (MID) with anode and cathode magnetic field coils has been tested on the NRL Gamble II accelerator. The purpose of the experiments is to develop an annular, intense ion beam source for testing ion beam transport physics related to light ion inertial confinement fusion. Initial experiments have been performed with surface flashover ion sources. The experimental challenge has been to obtain a tuning of the 4 magnetic field coils that results in a minimum turn-on time of the ion source and acceptable coupling to the accelerator. Results from several different geometries of magnetic field will be presented. The principal diode diagnostics are the total diode current, net ion current, and corrected diode voltage. Calculations of the magnetic field strength and geometry are performed with the ATHETA code. An active anode ion source is also under development. The initial portion of the accelerator pulse is diverted with a plasma opening switch (POS) and passed through a thin foil that will become the ion source. The foil is swiftly heated by the current pulse and gas is desorbed or diffused from the foil into the anode-cathode gap. The gas is then broken down by the current pulse, forming a dense plasma source on the anode surface. Two different foils are being used. A thin aluminum foil will work with desorbed gases, and provide a beam that is predominately protons. A hydrogen loaded titanium foil, with a paladium overcoating, will use diffused hydrogen, and produce a high purity proton beam. The net result of the POS and active anode plasma source should be much faster ion turn-on time, and better coupling of the ion source to the accelerator. Preliminary results with the active anode sources will be presented

  19. Fertile transgenic wheat from microprojectile bombardment of scutellar tissue.

    Science.gov (United States)

    Becker, D; Brettschneider, R; Lörz, H

    1994-02-01

    A reproducible transformation system for hexaploid wheat was developed based on particle bombardment of scutellar tissue of immature embryos. Particle bombardment was carried out using a PDS 1000/He gun. Plant material was bombarded with the plasmid pDB1 containing the beta-glucuronidase gene (uidA) under the control of the actin-1 promoter of rice, and the selectable marker gene bar (phosphinothricin acetyltransferase) under the control of the CaMV 35S promoter. Selection was carried out using the herbicide Basta (Glufosinate-ammonium). From a total number of 1050 bombarded immature embryos, in seven independent transformation experiments, 59 plants could be regenerated. Putative transformants were screened for enzyme activity by the histochemical GUS assay using cut leaf material and by spraying the whole plants with an aqueous solution of the herbicide Basta. Twelve regenerants survived Basta spraying and showed GUS-activity. Southern-blot analysis indicated the presence of introduced foreign genes in the genomic DNA of the transformants and both marker genes were present in all plants analysed. To date, four plants have been grown to maturity and set seed. Histochemically stained pollen grains showed a 1:1 segregation of the uidA gene in all plants tested. A 3:1 segregation of the introduced genes was demonstrated by enzyme activity tests and Southern blot analysis of R1 plants.

  20. Target bombardment by ion beams generated in the Focus experiment

    International Nuclear Information System (INIS)

    Bernard, Alain; Coudeville, Alain; Garconnet, J.-P.; Jolas, A.; Mascureau, J. de; Nazet, Christian.

    1976-01-01

    In a Mather-Focus experiment, it was shown that 80% of the neutron emitted were generated through bombardment. The apparatus was operated with various targets at a distance of 13mm from the anode. In the low pressure regime, a deuteron beam of high energy was produced. Its emission duration was measured using a CD 2 target [fr

  1. Stable transformation of the oomycete, Phytophthora infestans, using microprojectile bombardment

    DEFF Research Database (Denmark)

    Cvitanich, Cristina; Judelson, Howard S.

    2003-01-01

    Germinated asexual sporangia, zoospores, and mycelia of Phytophthora infestans were transformed to G418-resistance by microprojectile bombardment. After optimization, an average of 14 transformants/shot were obtained, using 10(6) germinated sporangia and gold particles coated with 1 microg...

  2. Ion bombardment effect on surface state of metal

    International Nuclear Information System (INIS)

    Vaulin, E.P.; Georgieva, N.E.; Martynenko, T.P.

    1990-01-01

    The effect of slow argon ion bombardment on the surface microstructure of polycrystalline copper as well as the effect of surface state on sputtering of D-16 polycrystalline alloy are experimentally studied. Reduction of copper surface roughness is observed. It is shown that the D-16 alloy sputtering coefficient is sensitive to the surface state within the limits of the destructed surface layer

  3. Diffusion processes in bombardment-induced surface topography

    International Nuclear Information System (INIS)

    Robinson, R.S.

    1984-01-01

    A treatment is given of the problem of surface diffusion processes occurring during surface topography development, whenever a surface is simultaneously seeded with impurities and ion bombarded. The development of controllable topography and the importance of surface diffusion parameters, which can be obtained during these studies, are also analyzed. 101 refs.; 7 figs.; 2 tabs

  4. On the reasons for bombarding uranium with slow neutrons

    International Nuclear Information System (INIS)

    Xu Diyu

    1997-01-01

    Form the concepts of slow neutrons, the binding energy and the excitation energy of complex nuclei, and the activation energy in nuclear fission, the four reasons for bombarding uranium with slow neutrons are summed up. Not only the reasons for uranium fission are brought in light, but also the micromechanism is dealt with

  5. Dating Howardite Melt Clasts: Evidence for an Extended Vestan Bombardment?

    Science.gov (United States)

    Cartwright, J. A.; Hodges, K. V.; Wadhwa, M.; Mittlefehldt, D. W.

    2016-01-01

    Howardites are polymict breccias that, together with eucrites and diogenites (HED), likely originate from the vestan surface (regolith/ megaregolith), and display a heterogeneous distribution of eucritic and diogenitic material. Melt clasts are also present alongside other regolithic features within howardites, and are noteworthy for their compositional variability and appearance. Melt clasts formed by impact events provide a snapshot of the timings and conditions of surface gardening and bombardment on the vestan surface. By dating such clasts, we aim to better constrain the timings of impact events on Vesta, and to establish whether the impact flux in the asteroid belt was similar to that on the Moon. As the Moon is used as the basis for characterising impact models of the inner solar system, it is necessary to verify that apparent wide-scale events are seen in other planetary bodies. In particular, the observed clustering of Apollo melt clast ages between 3.8-4.0 Ga has led to two hypotheses: 1) The Moon was subjected to a sudden event - 'Lunar Cataclysm' or period of 'Late Heavy Bombardment' (LHB), 2) The age cluster represents the end of an epoch of declining bombardment or 'Heavy Bombardment. No consensus has emerged regarding one or other hypothesis. We are testing these hypotheses by seeking evidence for such events in materials other than those derived from the Moon.

  6. Advances in fast-atom-bombardment mass spectroscopy

    International Nuclear Information System (INIS)

    Hemling, M.E.

    1986-01-01

    A comparison of fast atom bombardment and field desorption mass spectrometry was made to determine relative sensitivity and applicability. A series of glycosphingolipids and a series of protected oligonucleotides of known structure were analyzed to ascertain the potential utility of fast atom bombardment mass spectrometry in the structural elucidation of novel compounds in these classes. Negative ion mass markers were also developed. Fast atom bombardment was found to be one-to-two orders of magnitude more sensitive than field desorption based on the analysis of a limited number of compounds from several classes. Superior sensitivity was not universal and field desorption was clearly better in certain cases. In the negative ion mode in particular, fast atom bombardment was found to be a useful tool for the determination of the primary structure of glycosphingolipids and oligonucleotides. Carbohydrate sequence and branching information, and a fatty acid and lipid base composition were readily obtained from the mass spectra of glycosphingolipids while bidirectional nucleotide sequence, nucleotide base, and protecting group assignments were obtained for oligonucleotides. Based on this knowledge, a tentative structure of a human peripheral nervous system glycosphingolipid implicated in certain cases of disorders such as amyotrophic lateral sclerosis, Lou Gehrig's Disease, was proposed. Suitable negative ion mass markers were found in dispersions of poly(ethylene) and poly(propylene)glycols in a triethylenetetramine matrix, a matrix which also proved useful in the analysis of glycosphingolipids. These polyglycol dispersions provided ions for calibration to 2300 daltons

  7. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Science.gov (United States)

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  8. Neutron yields from bombardment of α-particles

    International Nuclear Information System (INIS)

    Nakasima, Ryuzo

    1982-09-01

    The thick target neutron yields from bombardment of <10 MeV α-particles are calculated based on the reaction cross sections. The results for the elements of Z < 15 are compared with existing calculated or measured neutron yield data. For the elements of 16 < Z < 50, elemental or isotopic neutron yields are calculated if the cross section data are available. (author)

  9. Computational modeling of plasma-flow switched foil implosions

    International Nuclear Information System (INIS)

    Lindemuth, I.R.

    1985-01-01

    A ''plasma-flow'', or ''commutator'', switch has been proposed as a means of achieving high dI/dt in a radially imploding metallic foil plasma. In this concept, an axially moving foil provides the initial coaxial gun discharge path for the prime power source and provides and ''integral'' inductive storage of magnetic energy. As the axially moving foil reaches the end of the coaxial gun, a radially imploding load foil is switched into the circuit. The authors have begun two-dimensional computer modeling of the two-foil implosion system. They use a magnetohydrodynamic (MHD) model which includes tabulated state and transport properties of the metallic foil material. Moving numerical grids are used to achieve adequate resolution of the moving foils. A variety of radiation models are used to compute the radiation generated when the imploding load foil converges on axis. These computations are attempting to examine the interaction of the switching foil with the load foil. In particular, they examine the relationship between foil placement and implosion quality

  10. 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

  11. Microparticle-initiated losses in magnetically insulated transmission lines

    International Nuclear Information System (INIS)

    Gray, E.W.; Stinnett, R.W.

    1986-01-01

    The author's discuss the effects of high and hypervelocity microparticles in magnetically-insulated transmission lines (MITLs) and how they may be a possible source for ion production near the anode in early stages of the voltage pulse, and current carriers during and after the power pulse, resulting in power flow losses. Early losses in the voltage pulse, due to microparticles, are estimated to be approximately 0.3 mA/cm/sup 2/. Blistering of the electrode surface, thought to be due to H/sup -/ bombardment, was also observed and appears to be consistent with losses due to negative ions previously reported by one of the authors

  12. Anomalous microstructural changes in III-nitrides under ion bombardment

    International Nuclear Information System (INIS)

    Kucheyev, S.O.; Williams, J.S.; Jagadish, C.

    2002-01-01

    Full text: Group-III nitrides (GaN, AlGaN, and InGaN) are currently a 'hot topic' in the physics and material research community due to very important technological applications of these materials in (opto)electronics. In the fabrication of III-nitride-based devices, ion bombardment represents a very attractive processing tool. However, ion-beam-produced lattice disorder and its undesirable consequences limit technological applications of ion implantation. Hence, studies of ion-beam-damage processes in Ill-nitrides are not only physically interesting but also technologically important. In this study, wurtzite GaN, AlGaN, and InGaN films exposed to ion bombardment under a wide range of irradiation conditions are studied by a combination of transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), energy dispersive x-ray spectrometry (EDS), atomic force microscopy (AFM), cathodoluminescence (CL), and Rutherford backscattering/channeling (RBS/C) spectrometry. Results show that, unlike the situation for mature semiconductors such as Si and GaAs, Ill-nitrides exhibit a range of intriguing behavior involving extreme microstructural changes under ion bombardment. In this presentation, the following aspects are discussed: (i) formation of lattice defects during ion bombardment, (ii) ion-beam-induced phase transformations, (iii) ion-beam-produced stoichiometric imbalance and associated material decomposition, and (iv) an application of charging phenomena during ESEM imaging for studies of electrical isolation in GaN by MeV light ion irradiation. Emphasis is given to the (powerful) application of electron microscopy techniques for the understanding of physical processes occurring in Ill-nitrides under ion bombardment. Copyright (2002) Australian Society for Electron Microscopy Inc

  13. Expectations for the Laguna foil implosion experiments

    International Nuclear Information System (INIS)

    Greene, A.; Brownell, J.; Caird, R.; Goforth, J.; Price, R.; Trainor, J.

    1987-01-01

    Building on the results achieved in the Pioneer shot series, the Los Alamos Trailmaster project is embarking on the Laguna foil implosion experiments. In this series a Mark-IX helical generator will be coupled to an explosively formed fuse opening switch, a surface-tracking closing switch, and a vacuum power flow and load chamber. In this paper the system design will be discussed and results from zero-, one-, and two-dimensional MHD simulations will be presented. It is anticipated that the generator will provide more than 10 MA of which ∼5.5 MA will be switched to the 5-cm-radius, 2-cm-high, 250-nm-thick aluminum foil load. This should give rise to a 1 μs implosion with more than 100 kJ of kinetic energy

  14. Composite metal foil and ceramic fabric materials

    Science.gov (United States)

    Webb, Brent J.; Antoniak, Zen I.; Prater, John T.; DeSteese, John G.

    1992-01-01

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed.

  15. Testing conformal mapping with kitchen aluminum foil

    OpenAIRE

    Haas, S.; Cooke, D. A.; Crivelli, P.

    2016-01-01

    We report an experimental verification of conformal mapping with kitchen aluminum foil. This experiment can be reproduced in any laboratory by undergraduate students and it is therefore an ideal experiment to introduce the concept of conformal mapping. The original problem was the distribution of the electric potential in a very long plate. The correct theoretical prediction was recently derived by A. Czarnecki (Can. J. Phys. 92, 1297 (2014)).

  16. Destruction of metallic foils under laser radiation

    International Nuclear Information System (INIS)

    Khokhlov, N.P.; Lisitsyn, Yu.V.; Mineev, V.N.; Ivanov, A.G.

    1975-01-01

    Experimental results are presented which illustrate the process of destruction of aluminium, lead and tantalum foils under irradiation of a neodymium laser, working in free generation regime with a power density varying from 5.10 5 - 5.10 6 wt/sq.cm. Calorimeters and photocells sensitive to the radiation with lambda=1.06 have been used for measuring the energy and recording the shape of the radiation pulse incident onto the target and passing through the disintegration products. The weight of the target has been determined prior to and after the experiment to find out the weight of Δm material expelled from the target. Rates of product scattering and a target destruction period, an amount of the material expelled and parameters of the radiation passing through the disintegration products have been determined as a function of the power density and an angle of the radiation incidence on the surface of the specimens. Average densities and absorption coefficients of the disintegration products of the foils under study have been assessed. A comparison of the characteristics of the metal foil (t 1 j) destruction in Pb-Ta-Al series with the metal thermal properties in this series shows that the destruction characteristics periodically vary as heat capacity, thermal conduction, evaporation heat and melting heat alter. A period of the target destruction becomes longer and the expelled mass smaller as the aforesaid thermal properties of the metals in Pb-Ta-Al series intensity [ru

  17. Brazing Inconel 625 Using the Copper Foil

    Science.gov (United States)

    Chen, Wen-Shiang; Wang, Cheng-Yen; Shiue, Ren-Kae

    2013-12-01

    Brazing Inconel 625 (IN-625) using the copper foil has been investigated in this research. The brazed joint is composed of nanosized CrNi3 precipitates and Cr/Mo/Nb/Ni quaternary compound in the Cu/Ni-rich matrix. The copper filler 50 μm in thickness is enough for the joint filling. However, the application of Cu foil 100 μm in thickness has little effect on the shear strength of the brazed joint. The specimen brazed at 1433 K (1160 °C) for 1800 seconds demonstrates the best shear strength of 470 MPa, and its fractograph is dominated by ductile dimple fracture with sliding marks. Decreasing the brazing temperature slightly decreases the shear strength of the brazed joint due to the presence of a few isolated solidification shrinkage voids smaller than 15 μm. Increasing the brazing temperature, especially for the specimen brazed at 1473 K (1200 °C), significantly deteriorates the shear strength of the joint below 260 MPa because of coalescence of isothermal solidification shrinkage voids in the joint. The Cu foil demonstrates potential in brazing IN-625 for industrial application.

  18. Self-propulsion of a pitching foil

    Science.gov (United States)

    Das, Anil; Shukla, Ratnesh; Govardhan, Raghuraman

    2017-11-01

    Undulatory motions serve as a fundamental mechanism for bio-locomotion at moderate and high Reynolds numbers. An understanding of the interactions between self-propelling undulatory motions and the surrounding fluid, not only provides insight into the efficiency of bio-locomotion, but also yields valuable pointers for the design of autonomous under-water and micro-aerial vehicles. Here, we investigate a simplified model of a self-propelling pitching foil that undergoes time-periodic oscillations about its quarter chord. We consider two-dimensional configurations in which the foil is free to propel along only longitudinal and both transverse and longitudinal directions. In both the configurations, the time-averaged self-propelling velocity increases monotonically with the Reynolds number Re (based on trailing edge speed and chord as the characteristic velocity and length). The rate of increase is particularly pronounced in the low Re regime (Re spaced wake vortices dissipate within a few chord lengths. At moderate and high Re, the wake exhibits increasingly complex structure in both the configurations. For a fixed Re, the foil with a single translational degree of freedom propels at a higher speed for a higher input power requirement. Differences between the two configurations will be discussed within the context of undulatory self-propulsion observed in nature.

  19. Panels of microporous insulation

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, J.A.; Morgan, D.E.; Jackson, J.D.J.

    1990-08-07

    Microporous thermal insulation materials have a lattice structure in which the average interstitial dimension is less than the mean free path of the molecules of air or other gas in which the material is arranged. This results in a heat flow which is less than that attributable to the molecular heat diffusion of the gas. According to this invention, a method is provided for manufacturing panels of microporous thermal insulation, in particular such panels in which the insulation material is bonded to a substrate. The method comprises the steps of applying a film of polyvinyl acetate emulsion to a non-porous substrate, and compacting powdery microporous thermal insulation material against the film so as to cause the consolidated insulation material to bond to the substrate and form a panel. The polyvinyl acetate may be applied by brushing or spraying, and is preferably allowed to dry prior to compacting the insulation material. 1 fig.

  20. Wall insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Kostek, P.T.

    1987-08-11

    In a channel specially designed to fasten semi-rigid mineral fibre insulation to masonry walls, it is known to be constructed from 20 gauge galvanized steel or other suitable material. The channel is designed to have pre-punched holes along its length for fastening of the channel to the drywall screw. The unique feature of the channel is the teeth running along its length which are pressed into the surface of the butted together sections of the insulation providing a strong grip between the two adjacent pieces of insulation. Of prime importance to the success of this system is the recent technological advancements of the mineral fibre itself which allow the teeth of the channel to engage the insulation fully and hold without mechanical support, rather than be repelled or pushed back by the inherent nature of the insulation material. After the insulation is secured to the masonry wall by concrete nail fastening systems, the drywall is screwed to the channel.

  1. 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

  2. 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

  3. Capillary self-alignment of mesoscopic foil components for sensor-systems-in-foil

    International Nuclear Information System (INIS)

    Arutinov, Gari; Smits, Edsger C P; Van Heck, Gert; Van den Brand, Jeroen; Schoo, Herman F M; Mastrangeli, Massimo; Dietzel, Andreas

    2012-01-01

    This paper reports on the effective use of capillary self-alignment for low-cost and time-efficient assembly of heterogeneous foil components into a smart electronic identification label. Particularly, we demonstrate the accurate (better than 50 µm) alignment of cm-sized functional foil dies. We investigated the role played by the assembly liquid, by the size and the weight of assembling dies and by their initial offsets in the self-alignment performance. It was shown that there is a definite range of initial offsets allowing dies to align with high accuracy and within approximately the same time window, irrespective of their initial offset. (paper)

  4. Study of thin insulating films using secondary ion emission

    International Nuclear Information System (INIS)

    Hilleret, Noel

    1973-01-01

    Secondary ion emission from insulating films was investigated using a CASTAING-SLODZIAN ion analyzer. Various different aspects of the problem were studied: charge flow across a silica film; the mobilization of sodium during ion bombardment; consequences of the introduction of oxygen on the emission of secondary ions from some solids; determination of the various characteristics of secondary ion emission from silica, silicon nitride and silicon. An example of measurements made using this type of operation is presented: profiles (concentration as a function of depth) of boron introduced by diffusion or implantation in thin films of silica on silicon or silicon nitride. Such measurements have applications in microelectronics. The same method of operation was extended to other types of insulating film, and in particular, to the metallurgical study of passivation films formed on the surface of stainless steels. (author) [fr

  5. Study of the electronic structure of pure aluminium, aluminium oxide and nitride by spectroscopy of electrons excited under electronic and photonic bombardment (X and UV)

    International Nuclear Information System (INIS)

    Gautier-Soyer, Martine

    1985-01-01

    This research thesis reports the use of electron spectroscopy with electrons excited under electronic or photonic (X or UV) bombardment for the study of electronic state density of aluminium, aluminium oxide (Al 2 O 3 ) and aluminium nitride (AlN). The objective is to get an insight into phenomena related to technological problems of adherence, wear, lubrication, corrosion or breakdown met in metals, insulators and semiconductors. The author highlighted the presence of occupied surface states on Al(111) and Al(100), and electronic levels localised in the forbidden band of Al 2 O 3 and AlN, induced by structural defects which promote surface reactivity [fr

  6. Ion bombardment simulation: a review related to fusion radiation damage

    International Nuclear Information System (INIS)

    Brimhall, J.L.

    1975-01-01

    Prime emphasis is given to reviewing the ion bombardment data on the refractory metals molybdenum, niobium and vanadium which have been proposed for use in advanced fusion devices. The temperature and dose dependence of the void parameters are correlated among these metals. The effect of helium and hydrogen gas on the void parameters is also included. The similarities and differences of the response of these materials to high dose, high temperature radiation damage are evaluated. Comparisons are made with results obtained from stainless steel and nickel base alloys. The ion bombardment data is then compared and correlated, as far as possible, with existing neutron data on the refractory metals. The theoretically calculated damage state produced by neutrons and ions is also briefly discussed and compared to experimental data wherever possible. The advantages and limitations of ion simulation in relation to fusion radiation damage are finally summarized

  7. A molecular dynamics study of helium bombardments on tungsten nanoparticles

    Science.gov (United States)

    Li, Min; Hou, Qing; Cui, Jiechao; Wang, Jun

    2018-06-01

    Molecular dynamics simulations were conducted to study the bombardment process of a single helium atom on a tungsten nanoparticle. Helium atoms ranging from 50 eV to 50 keV were injected into tungsten nanoparticles with a diameter in the range of 2-12 nm. The retention and reflection of projectiles and sputtering of nanoparticles were calculated at various times. The results were found to be relative to the nanoparticle size and projectile energy. The projectile energy of 100 eV contributes to the largest retention of helium atoms in tungsten nanoparticles. The most obvious difference in reflection exists in the range of 3-10 keV. Around 66% of sputtering atoms is in forward direction for projectiles with incident energy higher than 10 keV. Moreover, the axial direction of the nanoparticles was demonstrated to influence the bombardment to some degree.

  8. Development of pits and cones on ion bombarded copper

    International Nuclear Information System (INIS)

    Tanovic, L.A.; Carter, G.; Nobes, M.J.; Whitton, I.L.; Williams, J.S.

    1980-01-01

    The formation of pits and cones on Ar ion bombarded copper has been studied. Carefully polished surfaces of large grained 99.999% pure copper crystals have been bombarded at normal incidence with 40 keV argon ions. The cone formation has been investigated for annealed and non-annealed crystals at room temperature and at 30 K and in the case of monocrystal and polycrystal samples. Although in the most other studies the presence of impurities is as a necessary condition for generation of cones and pits the obtained experimental results show that under certain conditions these features are formed on clean surfaces. It is shown that the dominant parameter in the production of cones on copper is the crystal orientation [ru

  9. Diffusion processes in bombardment-induced surface topography

    International Nuclear Information System (INIS)

    Robinson, R.S.

    1984-01-01

    The bombardment of surfaces with moderate energy ions can lead to the development of various micron-sized surface structures. These structures include ridges, ledges, flat planes, pits and cones. The causal phenomena in the production of these features are sputtering, ion reflection, redeposition of sputtered material, and surface diffusion of both impurity and target-atom species. The authors concentrate on the formation of ion bombardment-induced surface topography wherein surface diffusion is a dominant process. The most thoroughly understood aspect of this topography development is the generation of cone-like structures during sputtering. The formation of cones during sputtering has been attributed to three effects. These are: (1) the presence of asperities, defects, or micro-inclusions in the surface layers, (2) the presence of impurities on the surfaces, and (3) particular crystal orientations. (Auth.)

  10. Miniature electron bombardment evaporation source: evaporation rate measurement

    International Nuclear Information System (INIS)

    Nehasil, V.; Masek, K.; Matolin, V.; Moreau, O.

    1997-01-01

    Miniature electron beam evaporation sources which operate on the principle of vaporization of source material, in the form of a tip, by electron bombardment are produced by several companies specialized in UHV equipment. These sources are used primarily for materials that are normally difficult to deposit due to their high evaporation temperature. They are appropriate for special applications such as heteroepitaxial thin film growth requiring a very low and well controlled deposition rate. A simple and easily applicable method of evaporation rate control is proposed. The method is based on the measurement of ion current produced by electron bombardment of evaporated atoms. The absolute evaporation flux values were measured by means of the Bayard-Alpert ion gauge, which enabled the ion current vs evaporation flux calibration curves to be plotted. (author). 1 tab., 4 figs., 6 refs

  11. Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

    Science.gov (United States)

    Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

    2010-01-01

    An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

  12. Translucent insulating building envelope

    DEFF Research Database (Denmark)

    Rahbek, Jens Eg

    1997-01-01

    A new type of translucent insulating material has been tested. This material is made of Celulose-Acetat and have a honey-comb structure. The material has a high solar transmittance and is highly insulating. The material is relatively cheap to produce. Danish Title: Translucent isolerende klimaskærm....

  13. Thermo-mechanical design aspects of mercury bombardment ion thrusters.

    Science.gov (United States)

    Schnelker, D. E.; Kami, S.

    1972-01-01

    The mechanical design criteria are presented as background considerations for solving problems associated with the thermomechanical design of mercury ion bombardment thrusters. Various analytical procedures are used to aid in the development of thruster subassemblies and components in the fields of heat transfer, vibration, and stress analysis. Examples of these techniques which provide computer solutions to predict and control stress levels encountered during launch and operation of thruster systems are discussed. Computer models of specific examples are presented.

  14. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  15. Quantification of steroid conjugates using fast atom bombardment mass spectrometry

    International Nuclear Information System (INIS)

    Gaskell, S.J.

    1990-01-01

    Fast atom bombardment/mass spectrometry or liquid secondary ion mass spectrometry provides the capability for direct analysis of steroid conjugates (sulfates, glucuronides) without prior hydrolysis or derivatization. During the analysis of biologic extracts, limitations on the sensitivity of detection arise from the presence of co-extracted material which may suppress or obscure the analyte signal. A procedure is described for the quantitative determination of dehydroepiandrosterone sulfate in serum which achieved selective isolation of the analyte using immunoadsorption extraction and highly specific detection using tandem mass spectrometry. A stable isotope-labeled analog [( 2H2]dehydroepiandrosterone sulfate) was used as internal standard. Fast atom bombardment of dehydroepiandrosterone sulfate yielded abundant [M-H]- ions that fragmented following collisional activation to give HSO4-; m/z 97. During fast atom bombardment/tandem mass spectrometry of serum extracts, a scan of precursor ions fragmenting to give m/z 97 detected dehydroepiandrosterone sulfate and the [2H2]-labeled analog with a selectivity markedly superior to that observed using conventional mass spectrometry detection. Satisfactory agreement was observed between quantitative data obtained in this way and data obtained by gas chromatography/mass spectrometry of the heptafluorobutyrates of dehydroepiandrosterone sulfate and [2H2]dehydroepiandrosterone sulfate obtained by direct derivatization. 21 refs

  16. Optical temperature sensing on flexible polymer foils

    Science.gov (United States)

    Sherman, Stanislav; Xiao, Yanfen; Hofmann, Meike; Schmidt, Thomas; Gleissner, Uwe; Zappe, Hans

    2016-04-01

    In contrast to established semiconductor waveguide-based or glass fiber-based integrated optical sensors, polymerbased optical systems offer tunable material properties, such as refractive index or viscosity, and thus provide additional degrees of freedom for sensor design and fabrication. Of particular interest in sensing applications are fully-integrated optical waveguide-based temperature sensors. These typically rely on Bragg gratings which induce a periodic refractive index variation in the waveguide so that a resonant wavelength of the structure is reflected.1,2 With broad-band excitation, a dip in the spectral output of the waveguide is thus generated at a precisely-defined wavelength. This resonant wavelength depends on the refractive index of the waveguide and the grating period, yet both of these quantities are temperature dependent by means of the thermo-optic effect (change in refractive index with temperature) and thermal expansion (change of the grating period with temperature). We show the design and fabrication of polymer waveguide-integrated temperature sensors based on Bragggratings, fabricated by replication technology on flexible PMMA foil substrates. The 175 μm thick foil serves as lower cladding for a polymeric waveguide fabricated from a custom-made UV-crosslinkable co-monomer composition. The fabrication of the grating structure includes a second replication step into a separate PMMA-foil. The dimensions of the Bragg-gratings are determined by simulations to set the bias point into the near infrared wavelength range, which allows Si-based detectors to be used. We present design considerations and performance data for the developed structures. The resulting sensor's signal is linear to temperature changes and shows a sensitivity of -306 nm/K, allowing high resolution temperature measurements.

  17. Stresses in the foil of an electron accelerator extraction channel

    International Nuclear Information System (INIS)

    Abroyan, M.A.; Makarenko, T.I.; Tokmakov, I.L.

    1983-01-01

    Stresses in the foil of an electron accelerator extraction channel are assessed with account of contributions of thermal expansion and stress concentrations during switchings. Optimization of extraction grid parameters of the electron accelerator extraction channel and choice of foil material for high current electron beam is conducted. It is suggested that an extraction grid with circular cells and Al-Mg foil should be used. A simple formula applicable for design calculations is proposed for evaluation of stress concentration coefficient during phase switchings

  18. Radiation pressure acceleration of ultrathin foils

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco [Department of Physics ' E. Fermi' , Largo B Pontecorvo 3, 56127 Pisa (Italy); Liseykina, Tatyana V, E-mail: macchi@df.unipi.i [Max Planck Institute for Nuclear Physics, Heidelberg (Germany)

    2010-04-15

    The acceleration of sub-wavelength, solid-density plasma foils by the ultraintense radiation pressure of circularly polarized laser pulses is investigated analytically and with simulations. An improved 'Light Sail' or accelerating mirror model, accounting for nonlinear self-induced transparency effects, is used for estimating the optimal thickness for acceleration. The model predictions are in good agreement with one-dimensional simulations. These latter are analyzed in detail to unfold the dynamics and self-organization of electrons and ions during the acceleration. Two-dimensional simulations are also performed to address the effects of target bending and of laser intensity inhomogeneity.

  19. 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.

  20. The Los Alamos foil implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Parker, J.; Bartsch, R.; Benage, J.; Bowers, R.; Cochrane, J.; Forman, P.; Goforth, J.; Greene, A.; Kruse, H.

    1993-01-01

    The goal of the Los Alamos foil implosion project is to produce an intense (>100 TW), multi-megajoule, laboratory soft x-ray source for material studies and fusion experiments. The concept involves the implosion of annular, current-carrying, cylindrical metallic plasmas via their self-magnetic forces. The project features inductive storage systems using both capacitor banks and high explosive-driven flux compression generators as prime energy sources. Fast opening switches are employed to shorten the electrical pulses. The program will be described and activities to date will be summarized

  1. LENA Conversion Foils Using Single-Layer Graphene, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Implementing graphene foils in existing neutral atom detector designs will increase their angular and energy resolution, and also improve their mass discrimination...

  2. Ti foil light in the ATA [Advanced Test Accelerator] beam

    International Nuclear Information System (INIS)

    Slaughter, D.R.; Chong, Y.P.; Goosman, D.R.; Rule, D.W.; Fiorito, R.B.

    1987-09-01

    An experiment is in progress to characterize the visible light produced when a Ti foil is immersed in the ATA 2 kA, 43 MeV beam. Results obtained to date indicate that the optical condition of the foil surface is a critical determinant of these characteristics, with a very narrow angular distribution obtained when a highly polished and flat foil is used. These data are consistent with the present hypothesis that the light is produced by transition radiation. Incomplete experiments to determine the foil angle dependence of the detected light and its polarization are summarized and remaining experiments are described

  3. Characterization of U-Mo Foils for AFIP-7

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Danny J.; Ermi, Ruby M.; Schemer-Kohrn, Alan L.; Overman, Nicole R.; Henager, Charles H.; Burkes, Douglas; Senor, David J.

    2012-11-07

    Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains.

  4. Apparatus and process for ultrasonic seam welding stainless steel foils

    Science.gov (United States)

    Leigh, Richard W.

    1992-01-01

    An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

  5. Thermohydrodynamic analysis of airfoil bearing based on bump foil structure

    Directory of Open Access Journals (Sweden)

    S.Y. Maraiy

    2016-09-01

    Full Text Available The load carrying capacity of the gas foil bearing depends on the material properties and the configuration of the underlying bump strip’s structure. This paper presents three different cases for selecting the dimensions of the foil bearing to guarantee the highest possible load carrying capacity. It focuses on three main parameters that affect the compliance number; these parameters are the length of bump in θ direction, the pitch of bump foil, and the thickness of bump foil. It also studies the effect of changing these parameters on load carrying capacity according to both isothermal and thermohydrodynamic approaches.

  6. Research on thermal insulation for hot gas ducts

    International Nuclear Information System (INIS)

    Broeckerhoff, P.

    1984-01-01

    The inner surfaces of prestressed reactor vessels and hot gas ducts of Gas Cooled High Temperature Reactors need internal thermal insulation to protect the pressure bearing walls from high temperatures. The design parameters of the insulation depend on the reactor type. In a PNP-plant temperature and pressure of the cooling medium helium are proposed to be 950 deg. C and 40 bars, respectively. The experimental work was started at KFA in 1971 for the HHT-project using three test facilities. At first metallic foil insulation and stuffed fibre insulating systems, the hot gas ducting shrouds of which were made of metal, have been tested. Because of the elevated helium temperature in case of PNP and the resulting lower strength of the metallic parts the interest was directed to rigid ceramic materials for the spacers and the inner shrouds. This led to modified structures designed by the INTERATOM company. Tests were performed at KFA. The main object of the investigations was to study the influence of temperature, pressure and axial pressure gradients on the thermal efficiency of the structures. Moreover, the temperatures within the insulation, at the pressure tube, and at the elements which bear the inner shrouds were measured. Thermal fluxes and effective thermal conductivities in axial and circumferential direction of the pressure tube are given, mainly for the INTERATOM-design with spherical spacers. (author)

  7. Vacuum insulation panels for building applications: A review and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Baetens, Ruben [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Laboratory of Building Physics, Department of Civil Engineering, Catholic University of Leuven (KUL), BE-3001 Heverlee (Belgium); Jelle, Bjoern Petter [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Thue, Jan Vincent [Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Tenpierik, Martin J. [Faculty of Architecture, Urbanism and Building Sciences, Delft University of Technology, Julianalaan 134, 2628 BL Delft (Netherlands); Grynning, Steinar; Uvsloekk, Sivert [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Gustavsen, Arild [Department of Architectural Design, History and Technology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway)

    2010-02-15

    Vacuum insulation panels (VIPs) are regarded as one of the most promising high performance thermal insulation solutions on the market today. Thermal performances three to six times better than still-air are achieved by applying a vacuum to an encapsulated micro-porous material, resulting in a great potential for combining the reduction of energy consumption in buildings with slim constructions. However, thermal bridging due to the panel envelope and degradation of thermal performance through time occurs with current technology. Furthermore, VIPs cannot be cut on site and the panels are fragile towards damaging. These effects have to be taken into account for building applications as they may diminish the overall usability and thermal performance. This paper is as far as the authors know the first comprehensive review on VIPs. Properties, requirements and possibilities of foil encapsulated VIPs for building applications are studied based on available literature, emphasizing thermal bridging and degradation through time. An extension is made towards gas-filled panels and aerogels, showing that other high performance thermal insulation solutions do exist. Combining the technology of these solutions and others may lead to a new leap forward. Feasible paths beyond VIPs are investigated and possibilities such as vacuum insulation materials (VIMs) and nano insulation materials (NIMs) are proposed. (author)

  8. Heat insulation support device

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Koda, Tomokazu; Motojima, Osamu; Yamamoto, Junya.

    1994-01-01

    The device of the present invention comprises a plurality of heat insulation legs disposed in a circumferential direction. Each of the heat insulative support legs has a hollow shape, and comprises an outer column and an inner column as support structures having a heat insulative property (heat insulative structure), and a thermal anchor which absorbs compulsory displacement by a thin flat plate (displacement absorber). The outer column, the thermal anchor and the inner column are connected by a support so as to offset the positional change of objects to be supported due to shrinkage when they are shrunk. In addition, the portion between the superconductive coils as the objects to be supported and the inner column is connected by the support. The superconductive thermonuclear device is entirely contained in a heat insulative vacuum vessel, and the heat insulative support legs are disposed on a lower lid of the heat insulative vacuum vessel. With such a constitution, they are strengthened against lateral load and buckling, thereby enabling to reduce the amount of heat intrusion while keeping the compulsory displacement easy to be absorbed. (I.N.)

  9. Actinide Foil Production for MPACT Research

    Energy Technology Data Exchange (ETDEWEB)

    Beller, Denis

    2012-10-30

    Sensitive fast-neutron detectors are required for use in lead slowing down spectrometry (LSDS), an active interrogation technique for used nuclear fuel assay for Materials Protection, Accounting, and Controls Technologies (MPACT). During the past several years UNLV sponsored a research project at RPI to investigate LSDS; began development of fission chamber detectors for use in LSDS experiments in collaboration with INL, LANL, and Oregon State U.; and participated in a LSDS experiment at LANL. In the LSDS technique, research has demonstrated that these fission chamber detectors must be sensitive to fission energy neutrons but insensitive to thermal-energy neutrons. Because most systems are highly sensitive to large thermal neutron populations due to the well-known large thermal cross section of 235U, even a miniscule amount of this isotope in a fission chamber will overwhelm the small population of higher-energy neutrons. Thus, fast-fission chamber detectors must be fabricated with highly depleted uranium (DU) or ultra-pure thorium (Th), which is about half as efficient as DU. Previous research conducted at RPI demonstrated that the required purity of DU for assay of used nuclear fuel using LSDS is less than 4 ppm 235U, material that until recently was not available in the U.S. In 2009 the PI purchased 3 grams of ultra-depleted uranium (uDU, 99.99998% 238U with just 0.2 ± 0.1 ppm 235U) from VNIIEF in Sarov, Russia. We received the material in the form of U3O8 powder in August of 2009, and verified its purity and depletion in a FY10 MPACT collaboration project. In addition, chemical processing for use in FC R&D was initiated, fission chamber detectors and a scanning alpha-particle spectrometer were developed, and foils were used in a preliminary LSDS experiment at a LANL/LANSCE in Sept. of 2010. The as-received U3O8 powder must be chemically processed to convert it to another chemical form while maintaining its purity, which then must be used to electro-deposit U

  10. 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

  11. Characterization of laser-cut copper foil X-pinches

    Science.gov (United States)

    Collins, G. W.; Valenzuela, J. C.; Hansen, S. B.; Wei, M. S.; Reed, C. T.; Forsman, A. C.; Beg, F. N.

    2016-10-01

    Quantitative data analyses of laser-cut Cu foil X-pinch experiments on the 150 ns quarter-period, ˜250 kA GenASIS driver are presented. Three different foil designs are tested to determine the effects of initial structure on pinch outcome. Foil X-pinch data are also presented alongside the results from wire X-pinches with comparable mass. The X-ray flux and temporal profile of the emission from foil X-pinches differed significantly from that of wire X-pinches, with all emission from the foil X-pinches confined to a ˜3 ns period as opposed to the delayed, long-lasting electron beam emission common in wire X-pinches. Spectroscopic data show K-shell as well as significant L-shell emission from both foil and wire X-pinches. Fits to synthetic spectra using the SCRAM code suggest that pinching foil X's produced a ˜1 keV, ne ≥ 1023 cm-3 plasma. The spectral data combined with the improved reliability of the source timing, flux, and location indicate that foil X-pinches generate a reproducible, K-shell point-projection radiography source that can be easily modified and tailored to suit backlighting needs across a variety of applications.

  12. 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.

  13. Foil fabrication for the ROMANO event. Revision 1

    International Nuclear Information System (INIS)

    Romo, J.G. Jr.; Weed, J.W.; Griggs, G.E.; Brown, T.G.; Tassano, P.L.

    1984-01-01

    The Vacuum Processes Lab (VPL), of LLNL's M.E. Dept. - Material Fabrication Division (MFD), conducted various vacuum related support activities for the ROMANO nuclear physics experiment. This report focuses on the foil fabrication activities carried out between July and November 1983 for the ROMANO event. Other vacuum related activities for ROMANO, such as outgassing tests of materials, are covered in separate documentation. VPL was asked to provide 270 coated Parylene foils for the ROMANO event. However, due to the developmental nature of some of the procedures, approximately 400 coated foils were processed. In addition, VPL interacted with MFD's Plastics Shop to help supply Parylene substrates to other organizations (i.e., LBL and commercial vendors) which had also been asked to provide coated foils for ROMANO. The purposes of this report are (A) to document the processes developed and the techniques used to produce the foils, and (B) to suggest future directions. The report is divided into four sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, (3) calibration foil fabrication, and (4) foil and substrate inspections

  14. Practical and research aspects of beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Bashkin, S.

    1974-01-01

    Practical aspects of the application of low-energy accelerators to research in beam-foil spectroscopy are discussed, and the kinds of equipment and associated costs are described in some detail. Some typical beam-foil experiments, emphasizing the most recent studies, are treated so as to show how relatively simple facilities can be used to produce physics of great interest

  15. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  16. Gas insulated substations

    CERN Document Server

    2014-01-01

    This book provides an overview on the particular development steps of gas insulated high-voltage switchgear, and is based on the information given with the editor's tutorial. The theory is kept low only as much as it is needed to understand gas insulated technology, with the main focus of the book being on delivering practical application knowledge. It discusses some introductory and advanced aspects in the meaning of applications. The start of the book presents the theory of Gas Insulated Technology, and outlines reliability, design, safety, grounding and bonding, and factors for choosing GIS. The third chapter presents the technology, covering the following in detail: manufacturing, specification, instrument transformers, Gas Insulated Bus, and the assembly process. Next, the book goes into control and monitoring, which covers local control cabinet, bay controller, control schemes, and digital communication. Testing is explained in the middle of the book before installation and energization. Importantly, ...

  17. Gas amplification properties of GEM foils

    International Nuclear Information System (INIS)

    Beck, Jeannine

    2009-01-01

    In the framework of the detector concept International Linear Detector for the future accelerator project International Linear Collider, in which electrons and positrons at c. m. energies of 500 GeV are brought to collision, a time projection chamber shall be applied as central track detector. By the application of such a chamber as track detector a three-dimensional reconstruction of the track points is possible. If a particle passes the gas volume within the chamber it ionizises single gas atoms and the arising electrons move after the amplification in the GEM arrangement to the anode, so that a two-dimensional projection of the particle track is possible. The third dimension is calculated from the drift time of the electrons. The advances of this readout system consist therein that a better position resolution than by a multiwire proportional chamber is reached and the back-drifting ions can be strongly suppressed. Aim of this thesis are studies for a GEM module, which shall be used in a large TPC prototype. Concerning different requirements it is valid to compare different GEMs in order to can meet an optimal choice. In a small prototype present at DESY measurements for the acquisition of GEM-describing parameters were performed. The taking into operation of the test TPC was part of this thesis. Tracks were generated by a radioactive source, by means of which the gas amplification was determined. With the measurement arrangement gas-amplifier foils of different kind were compared in view of their amplification properties and their energy resolution power and systematically studied. Five different GEM performances were studied in the test TPC. These foils differ in their geometrical classification parameters, the fabrication process, or the materials. The GEMs produced at CERN possess in comparison with GEMs of the Japanese firm SciEnergy and a GEM of the US-American firm Tech-Etch the best amplification and resolution properties. Furthermore a new GEM framing

  18. 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)

  19. A comparison of atom and ion induced SSIMS - evidence for a charge induced damage effect in insulator materials

    International Nuclear Information System (INIS)

    Brown, A.; Berg, J.A. van den; Vickerman, J.C.

    1985-01-01

    A static secondary ion mass spectrometry (SSIMS) study of two very low conductivity materials, polystyrene and niobium pentoxide, using on the one hand a primary ion beam with electron neutralisation, and on the other, atom bombardment, shows that whilst the initial spectra obtained were quite similar, subsequent damage effects were much greater under ion impact conditions. For an equivalent flux density the half-life of the polystyrene surface structure was four times longer under atom bombardment. Significant reduction of the niobium surface was observed under ion bombardment whereas an equivalent atom flux had little apparent effect on the surface oxidation state. These data suggest that the requirement to dissipate the charge delivered to the sample by the primary ion beam contributes significantly to the damage mechanisms in electrically insulating materials. (author)

  20. Facies of ion bombarded surfaces of brittle materials

    International Nuclear Information System (INIS)

    Primak, W.

    1975-12-01

    Materials were bombarded by protons, deuterons, and helium ions. The materials investigated were quartz; glasses; carbides and borides (SiC, B 4 C, TiB 2 ); oxides and nitrides (magnorite, sapphire, spinel, Al 2 O 3 , Si 3 N 4 , ZrO 2 , BaTiO 3 ); and miscellaneous (graphite, LiNbO 3 , copper). Oberservations were of growth, reflectivity, blistering, surface ablation, and swelling. Calculations were made of the effects of a layer, of its gradual transformation, and of the introduction of a gas. It is concluded that: Radiation blistering is not a primary process. Observations of blister formation and exfoliation cannot be used to calculate the surface ablation rate. The primary process is the development of a microporous layer which causes swelling. Visible blisters are caused by fracturing by transverse stresses in this layer and may occur during the bombardment, or in some cases, much later, in storage. There is no evidence of extreme gas pressures in the blisters. When blisters develop, they may be stable under continued bombardment for a dose many times that at which they formed. The swelling is a better index of the effects than is the blistering, and must be associated in most cases with permeability to the gas. Behavior with protons and deuterons is similar, with helium different. All but quartz, vitreous silica, and Pyrex are impervious to hydrogen and deuterium; only dense barium crown glass, carbides, borides, oxides, and nitrides are impervious to helium. Quartz shows swelling caused by conversion to a vitreous product of much lower density but no porosity, while for the others, most of the swelling and surface growth is caused by porosity. Surface ablation by the blistering process may be reduced by initial porosity or by initial or subsequent surface fissuring. However, for impervious materials, surface damage by the introduction of porosity would continue

  1. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  2. High resistivity in InP by helium bombardment

    International Nuclear Information System (INIS)

    Focht, M.W.; Macrander, A.T.; Schwartz, B.; Feldman, L.C.

    1984-01-01

    Helium implants over a fluence range from 10 11 to 10 16 ions/cm 2 , reproducibly form high resistivity regions in both p- and n-type InP. Average resistivities of greater than 10 9 Ω cm for p-type InP and of 10 3 Ω cm for n-type InP are reported. Results are presented of a Monte Carlo simulation of helium bombardment into the compound target InP that yields the mean projected range and the range straggling

  3. 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

  4. Survey of thermal insulation systems

    International Nuclear Information System (INIS)

    Kinoshita, Izumi

    1983-01-01

    Better thermal insulations have been developed to meet the growing demands of industry, and studies on thermal insulation at both high temperature and low temperature have been widely performed. The purpose of this survey is to summarize data on the performances and characteristics of thermal insulation materials and thermal insulation structures (for instance, gas cooled reactors, space vehicles and LNG storage tanks), and to discuss ravious problems regarding the design of thermal insulation structures of pool-type LMFBRs. (author)

  5. Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

    Energy Technology Data Exchange (ETDEWEB)

    Semsang, Nuananong, E-mail: nsemsang@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, LiangDeng [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► Ion beam bombarded rice seeds in vacuum. ► Studied seed survival from the ion bombardment. ► Determined various antioxidant enzyme activities and lipid peroxidation level. ► Discussed vacuum, ion species and ion energy effects. ► Attributed the changes to free radical formation due to ion bombardment. -- Abstract: Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29–60 keV and ion fluences of 1 × 10{sup 16} ions cm{sup −2}. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

  6. Direct evidence for a thermal effect of Ar+ ion bombardment in a conventional sputtering mode

    International Nuclear Information System (INIS)

    Okuyama, F.; Fujimoto, Y.

    1986-01-01

    Evidence is presented that the Ar + ion bombardment for sputtering in Auger electron spectroscopy can heat the target up to 2000 0 C if the target has poor heat conduction. Polycrystalline microneedles of Cr exhibited spherical tips after being exposed to 3 keV Ar + ions, proving that the needle tips were melted by impacting Ar + ions. Microneedles of Mo ion bombarded under the same condition were bent plastically, which perhaps reflects the thermal annealing of the needles during ion bombardment

  7. Plasma flow switch characterization for the Los Alamos Foil Implosion Project

    International Nuclear Information System (INIS)

    Bowers, R.L.; Brownell, J.H.; Greene, A.E.; Peterson, D.L.

    1990-01-01

    The next system design under consideration for the Los Alamos Foil Implosion Project is projected to deliver tens of mega-amperes of electrical current produced by high-explosive driven flux compression generators on a time scale of about one microsecond to a load foil. The use of such generators, with time scales of order several tenths of a millisecond, leads to considerable pulse shaping problems. Previously it was noted that a commutating switch might serve as an efficient alternative to a closing switch in transferring current from a coaxial transmission line to a cylindrically imploding load. Research at the Air Force Weapons Laboratory (AFWL) has met with considerable success in efficiently transferring currents of order 10 MA to an imploding liner using the plasma flow switch concept (PFS). Besides efficiently transferring current, the plasma flow switch protects the load region from high voltages generated by an opening switch until the current is present to provide magnetic insulation. For these reasons, a PFS is being investigated as the final pulse shaping step in the design. A series of capacitor bank experiments is also being fielded to help investigate physics issues and to benchmark the codes

  8. High dose He/sup +/ bombardment of niobium at 800/sup 0/ to 1400/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Biersack, J P [Hahn-Meitner-Institut fuer Kernforschung Berlin G.m.b.H. (Germany, F.R.)

    1976-12-01

    In proposed fusion reactors, the first wall will be bombarded by low energy D/sup +/, T/sup +/ and He/sup +/ ions to very high doses. Room temperature irradiations with 9 keV He/sup +/ (Roth et al. 1975) showed an initial phase of blistering between 0.05 and 0.25 C/cm/sup 2/, and a final state of considerable surface roughness at 8 to 112 C/cm/sup 2/(7 x 10/sup 20/He/sup +//cm/sup 2/). The present irradiation experiments with 6 keV He/sup +/ are carried out with polycrystalline Nb foils at temperatures between 800 and 1400/sup 0/C in order to study the influence of He mobility and of Nb surface diffusion during irradiation. The applied doses range from 2.5 x 10/sup 17/He/sup +//cm/sup 2/ (blistering) to 5 x 10/sup 20/He/sup +//cm/sup 2/ which corresponds to at least several weeks of reactor operation. The resulting changes of the niobium surface structures are observed by scanning electron microscopy and are pictorially presented in this paper. Mainly, sponge-like open structures are seen to develop at high doses, with increasing physical dimensions at higher temperatures.

  9. Experiment and analysis of neutron spectra in a concrete assembly bombarded by 14 MeV neutrons

    International Nuclear Information System (INIS)

    Oishi, Koji; Tomioka, Kazuyuki; Ikeda, Yujiro; Nakamura, Tomoo.

    1988-01-01

    Neutron spectrum in concrete bombarded by 14 MeV neutrons was measured using a miniature NE213 spectrometer and multi-foil activation method. A good agreement between those two experimental methods was obtained within experimental errors. The measured spectrum was compared with calculated ones using two-dimensional transport code DOT3.5 with 125 group structure cross section libraries based on ENDF/B-IV, JENDL-2, and JENDL-3T (the testing version of JENDL-3.) In the D-T neutron peak region, measured and calculated neutron spectra agreed well with each other for those libraries. However, disagreements of about -10 % to +50 % and -30 % to +40 % were obtained in the MeV region and still lower neutron energy range, respectively. As a result, it was concluded that those discrepancies were caused by the overestimation of secondary neutrons emitted by inelastic scattering from O, Si, and/or Ca which were the main components of concrete. (author)

  10. Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

    Science.gov (United States)

    Semsang, Nuananong; Yu, LiangDeng

    2013-07-01

    Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29-60 keV and ion fluences of 1 × 1016 ions cm-2. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

  11. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2014-05-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms.

  12. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    International Nuclear Information System (INIS)

    Thopan, P.; Thongkumkoon, P.; Prakrajang, K.; Suwannakachorn, D.; Yu, L.D.

    2014-01-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms

  13. The new generations of power components will depend on neutron and/or electron bombardment techniques

    International Nuclear Information System (INIS)

    Lilen, H.

    1976-01-01

    Neutron and electron bombardment techniques for materials doping, newly introduced in the fabrication of power semiconductor components: diodes, transistors, thyristors, and triacs are briefly outlined. A neutron bombardment of high purity silicon results in a short-lived 31 Si isotope (from 30 Si) decaying into 31 P. The phosphorus with its five peripheral electrons induces a negative doping (N), and the neutron technique gives a homogeneous doping. Furthermore, silicon bombardment with 1 to 2MeV electrons induces micro-ruptures in the lattice, that act as recombination traps reducing carrier lifetimes. Consequently, gold diffusion techniques can be replaced by electron bombardment with a gain in controlling carrier lifetimes [fr

  14. Model to estimate fractal dimension for ion-bombarded materials

    Energy Technology Data Exchange (ETDEWEB)

    Hu, A., E-mail: hu77@purdue.edu; Hassanein, A.

    2014-03-15

    Comprehensive fractal Monte Carlo model ITMC-F (Hu and Hassanein, 2012 [1]) is developed based on the Monte Carlo ion bombardment simulation code, i.e., Ion Transport in Materials and Compounds (ITMC) code (Hassanein, 1985 [2]). The ITMC-F studies the impact of surface roughness on the angular dependence of sputtering yield. Instead of assuming material surfaces to be flat or composed of exact self-similar fractals in simulation, we developed a new method to describe the surface shapes. Random fractal surfaces which are generated by midpoint displacement algorithm and support vector machine algorithm are combined with ITMC. With this new fractal version of ITMC-F, we successfully simulated the angular dependence of sputtering yield for various ion-target combinations, with the input surface roughness exponent directly depicted from experimental data (Hu and Hassanein, 2012 [1]). The ITMC-F code showed good agreement with the experimental data. In advanced, we compare other experimental sputtering yield with the results from ITMC-F to estimate the surface roughness exponent for ion-bombarded material in this research.

  15. Damage and redistribution of impurities by ionic bombardment

    International Nuclear Information System (INIS)

    Tognetti, N.P.

    1982-01-01

    Some aspects of displacement collisions in solids bombarded with ions in the medium energy range have been studied using the backscattering and channelling techniques. The production of lattice damage and the spatial redistribution of atoms within the collision cascade were the two main effects considered and experimentally studied. A comprehensive study of disorder production in GaAs was carried out at 40 K for a variety of ions and ion energies, providing insight into the mechanisms of damage generation from both the macro and microscopic points of view. Experiments on thermal recovery of partially disordered substrates revealed that annealing occurs from approximately 100 K to 300 K. A direct procedure developed for the obtainment of damage profiles from backscattering-channelling measurements is described. The net spatial redistribution of displaced atoms, in combined impurity-matrix substrates was studied and compared with existing theories of ion beam mixing. The Ag-Si system was studied for a wide range of fluence of bombarding Ar + ions. Furthermore, the contribution of atomic mixing in the experimental observation of Ge implantation at high doses into Si is discussed. (M.E.L) [es

  16. Chemical changes in titanate surfaces induced by Ar+ ion bombardment

    International Nuclear Information System (INIS)

    Gonzalez-Elipe, A.R.; Fernandez, A.; Espinos, J.P.; Munuera, G.; Sanz, J.M.

    1992-01-01

    The reduction effects and compositional changes induced by 3.5 keV Ar + bombardment of several titanates (i.e. SrTiO 3 , Al 2 TiO 5 and NiTiO 3 ) have been quantitatively investigated by XPS. In all the samples studied here the original Ti 4+ species were reduced to lower oxidation states (i.e. Ti 3+ and Ti 2+ ), although to a lesser extent than in pure TiO 2 . On the contrary, whereas Sr 2+ and Al 3+ seem to remain unaffected by Ar + bombardment, in agreement with the behaviour of the respective oxides (i.e. SrO and Al 2 O 3 ), Ni 2+ appears more easily reducible to Ni o in NiTiO 3 than in NiO. In addition, other specific differences were observed between the titanates, which reveal the existence of interesting chemical effects related to the presence of the different counter-ions in the titanates. In the case of Al 2 TiO 5 , its Ar + -induced decomposition to form TiO 2 + Al 2 O 3 could be followed by XPS. (Author)

  17. Continuum radiation emitted from transition metals under ion bombardment

    International Nuclear Information System (INIS)

    El Boujlaidi, A.; Kaddouri, A.; Ait El Fqih, M.; Hammoum, K.; Aouchiche, H.

    2012-01-01

    Optical emission of transition metals has been studied during 5 keV Kr + ions bombardment within and without oxygen atmosphere in the colliding chamber. The observed spectra consist of a series of discrete lines superimposed on a broad continuum. Generally, the emission intensity was influenced by the presence of oxygen giving rise to transient effects as well as to an increase in the line intensity. The behaviours of spectral lines were successfully explained in term of electron-transfer process between the excited sputtered atom and the solid surface. In this work, we have focused our study on the continuous radiation emitted during ion bombardment. The experimental results suggest that the continuum emission depends on the nature of metal and very probably related to its electronic structure. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation. The observed enhancement in the presence of oxygen is probably due to a significant contribution of the oxide molecules. (authors)

  18. Universality of spectator fragmentation at relativistic bombarding energies

    International Nuclear Information System (INIS)

    Schuettauf, A.; Woerner, A.

    1996-06-01

    Multi-fragment decays of 129 Xe, 197 Au, and 238 U projectiles in collisions with Be, C, Al, Cu, In, Au, and U targets at energies between E/A=400 MeV and 1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By adding an array of 84 Si-CsI(Tl) telescopes the solid-angle coverage of the setup was extended to θ lab =16 . This permitted the complete detection of fragments from the projectile-spectator source. The dominant feature of the systematic set of data is the Z bound universality that is obeyed by the fragment multiplicities and correlations. These observables are invariant with respect to the entrance channel if plotted as a function of Z bound , where Z bound is the sum of the atomic numbers Z i of all projectile fragments with Z i ≥2. No significant dependence on the bombarding energy nor on the target mass is observed. The dependence of the fragment multiplicity on the projectile mass follows a linear scaling law. The reasons for and the limits of the observed universality of spectator fragmentation are explored within the realm of the available data and with model studies. It is found that the universal properties should persist up to much higher bombarding energies than explored in this work and that they are consistent with universal features exhibited by the intranuclear cascade and statistical multifragmentation models. (orig.)

  19. Flaking and blistering on He and Ne bombardments

    International Nuclear Information System (INIS)

    Kamada, K.; Naramoto, H.

    1979-01-01

    Large scale exfoliation formed by 300 keV He + bombardment of niobium without any preceding blistering is investigated, in comparison with the blistering due to 450 and 850 keV Ne + bombardments. In-situ observations of the erosion processes were performed in a scanning electron microscope connected to the Van de Graaff. Critical doses of 7.2 x 10 17 He + /cm 2 , 2.4 x 10 17 Ne + /cm 2 and 4.0 x 10 17 Ne + /cm 2 were obtained for the 300 keV He flaking, 450 keV Ne blistering and 850 keV Ne blistering, respectively. The He flaking was presumed to be due to brittle fashion peeling-off of the surface layer by the bending moment driven by the internal gas pressure. The blistering, on the other hand, was presumed to be the result of the ductile fashion spreading of the lenticular bubble in the sub-surface layer. The necessary pressure for the peeling-off of the cover was calculated, and was speculated to be able to work as the driving force for the flaking from its unexpectedly low values. Fractographies under the exfoliations were discussed for both flaking and blistering. (author)

  20. Interaction of slow highly-charged ions with metals and insulators

    International Nuclear Information System (INIS)

    Yamazaki, Y.

    2007-01-01

    Interaction of slow highly charged ions with insulator as well as metallic surfaces is discussed. In addition to the usual flat surface targets, studies with thin foils having a multitude of straight holes of ∼100 nm in diameter (micro-capillary foil) are introduced, which provide various unique information on the above surface interaction. In the case of an insulator micro-capillary foil, a so-called guiding effect was observed, where slow highly charged ions can transmit through the capillary tunnel keeping their initial charge state even when the capillary axis is tilted against the incident beam. A similar guiding effect has recently been found for slow highly-charged ions transmitted through a single tapered glass capillary. In both cases, the guiding effects are expected to be governed by a self-organized charging and discharging of the inner-wall of the insulator capillary. One of the prominent features of this guiding effect with the tapered capillary is the formation of a nano-size beam, which can be applied in various fields of science including surface nano-modification/analysis, nano-surgery of living cells, etc

  1. Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

    Energy Technology Data Exchange (ETDEWEB)

    Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

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

  2. Effects of the Addictives on Etching Characteristics of Aluminum Foil

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.K.; Jang, J.M.; Chi, C.S. [Kookmin University, Seoul (Korea); Shin, D.C. [Sungnam Polytechnic, Sungnam (Korea); Lee, J.H.; Oh, H.J. [Hanseo University, Seosan (Korea)

    2001-01-01

    The effects of additives in the HCI etching solution on etching behaviors of aluminium foil as dielectric film for electrolytic capacitors were investigated. The etch pits formed in 1M hydrochloric acid containing ethylene glycol as an additive contain more fine and homogeneous etch tunnels compared to thoese in 1 M hydrochloric acid only, which led to the increase in the effective internal surface area of aluminum foil. After anodizing of aluminum foil etched in etching solutions, the LCR meter results have shown that the capacitance of dielectric film etched in hydrochloric acid with ethylene glycol was increased remarkably compared to that etched in hydrochloric acid only. (author). 21 refs., 10 figs.

  3. Preparation of self-supporting metallic foils of nickel isotopes

    International Nuclear Information System (INIS)

    Sugai, Isao.

    1975-01-01

    This is the fourth report on the practical methods of target preparation for use in low energy nuclear experiments following the previous one (INS-J-150). An electroplating method has been developed as a dependable and reproducible technique for making self-supporting metallic foils of nickel in the thickness range of 0.5 to 10 mg/cm 2 . The procedures minimized the necessary amount of material so that nickel isotopes could be processed economically. Impurity contamination of the nickel foils during the electroplating process was less than 500 ppm, and the thickness variation in each foil was less than 3% of the central thickness. (auth.)

  4. 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.

  5. 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.)

  6. Reusable Surface Insulation

    Science.gov (United States)

    1997-01-01

    Advanced Flexible Reusable Surface Insulation, developed by Ames Research Center, protects the Space Shuttle from the searing heat that engulfs it on reentry into the Earth's atmosphere. Initially integrated into the Space Shuttle by Rockwell International, production was transferred to Hi-Temp Insulation Inc. in 1974. Over the years, Hi-Temp has created many new technologies to meet the requirements of the Space Shuttle program. This expertise is also used commercially, including insulation blankets to cover aircrafts parts, fire barrier material to protect aircraft engine cowlings and aircraft rescue fire fighter suits. A Fire Protection Division has also been established, offering the first suit designed exclusively by and for aircraft rescue fire fighters. Hi-Temp is a supplier to the Los Angeles City Fire Department as well as other major U.S. civil and military fire departments.

  7. Insulators for fusion applications

    International Nuclear Information System (INIS)

    1987-04-01

    Design studies for fusion devices and reactors have become more detailed in recent years and with this has come a better understanding of requirements and operating conditions for insulators in these machines. Ceramic and organic insulators are widely used for many components of fusion devices and reactors namely: radio frequency (RF) energy injection systems (BeO, Al 2 O 3 , Mg Al 2 O 4 , Si 3 N 4 ); electrical insulation for the torus structure (SiC, Al 2 O 3 , MgO, Mg Al 2 O 4 , Si 4 Al 2 O 2 N 6 , Si 3 N 4 , Y 2 O 3 ); lightly-shielded magnetic coils (MgO, MgAl 2 O 4 ); the toroidal field coil (epoxies, polyimides), neutron shield (B 4 C, TiH 2 ); high efficiency electrical generation; as well as the generation of very high temperatures for high efficiency hydrogen production processes (ZrO 2 and Al 2 O 3 - mat, graphite and carbon - felt). Timely development of insulators for fusion applications is clearly necessary. Those materials to be used in fusion machines should show high resistance to radiation damage and maintain their structural integrity. Now the need is urgent for a variety of radiation resistant materials, but much effort in these areas is required for insulators to be considered seriously by the design community. This document contains 14 papers from an IAEA meeting. It was the objective of this meeting to identify existing problems in analysing various situations of applications and requirements of electrical insulators and ceramics in fusion and to recommend strategies and different stages of implementation. This meeting was endorsed by the International Fusion Research Council

  8. Evidence Supporting an Early as Well as Late Heavy Bombardment on the Moon

    Science.gov (United States)

    Frey, Herbert

    2015-01-01

    Evidence supporting an intense early bombardment on the Moon in addition to the traditional Late Heavy Bombardment at approx. 4 BY ago include the distribution of N(50) Crater Retention Ages (CRAs) for candidate basins, a variety of absolute age scenarios for both a "young" and an "old" Nectaris age, and the decreasing contrasts in both topographic relief and Bouguer gravity with increasing CRA.

  9. Ion bombardment effects on surface states in selected oxide systems: rutile and alkaline earth titanates

    International Nuclear Information System (INIS)

    Gruen, D.M.

    1978-01-01

    In this paper, the nature of the surface states of n-type TiO 2 and SrTiO 3 is discussed and the role of ion bombardment in modifying the properties of these states is elucidated. Insofar as possible, the interrelationships between oxide nonstoichiometry, surface states, ion bombardment effects and photoelectrolysis are explored

  10. 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.

  11. Method of stabilizing Nb3Sn superconducting foils

    International Nuclear Information System (INIS)

    Kruzliak, J.; Lences, P.; Allarova, H.

    1982-01-01

    The stabilization of niobium-tin Nb 3 Sn superconducting foils with copper is carried out by deposition or by diffusion in pure copper or in a tin bath containing different copper levels, with the surface etched or unetched. The foils are covered with a copper film at a temperature of 300 to 5O0 degC using a tin solder, spread on a copper, silver or nickel layer deposited on the foil surface from solutions for electroless plating. The bond between the surface of the superconducting foil and the electroless plated metal layer is annealed in a controlled atmosphere or in a vacuum at a temperature of 200 to 500 degC for over 20 to 60 minutes. The copper stabilization layer can also be produced electrolytically. (J.B.)

  12. 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.)

  13. Decontamination with pasty pickling agents forming a strippable foil

    International Nuclear Information System (INIS)

    Weichselgartner, H.

    1991-01-01

    This paper describes the development of an in-situ decontamination procedure by applying onto the contaminated surface (in an one-step or multi-step process) pasty, chemically aggressive agents causing dilution and adsorption of the contaminant and then hardening to form a strippable foil. The use of such a foil will result in following advantages, with respect to usual techniques: - sensibly shorter operation duration resulting in lower personnel doses; - reduction of the arising secondary waste volume because there is no need for washing; the volume of the spent strippable foil is much smaller than currently used water volumes; - optimal conditioning of the radioactive waste due to its fixation in a solid (foil); - an accidental contamination in a controlled area can easily be fixed and covered avoiding its propagation

  14. Design of foil implosion system for Pioneer I experiments

    International Nuclear Information System (INIS)

    Erickson, D.J.; Caird, R.S.; Fowler, C.M.

    1985-01-01

    A foil implosion system is described that integrates an explosive flux-compression generator, a flat plate feed section with power conditioning switches, and a vacuum electrode region containing a cylindrical foil/plasma load. Power conditioning, obtained with an explosive-driven plasma compression opening switch and explosive-actuated closing switches, provides a submicrosecond multimegampere pulse for the implosion of an aluminum plasma. The flat plate section is configured for bidirectional feed to the coaxial vacuum electrodes. Important considerations in the design of the vacuum power flow region include gap failure, feed symmetry, and radial diagnostic access. The system presently accommodates a foil radius of 3 cm. Innovative foil insertion and clamping techniques are also described

  15. A Unique Photon Bombardment System for Space Applications

    Science.gov (United States)

    Klein, E. J.

    1993-01-01

    The innovative Electromagnetic Radiation Collection and Concentration System (EMRCCS) described is the foundation for the development of a multiplicity of space and terrestrial system formats. The system capability allows its use in the visual, infrared, and ultraviolet ranges of the spectrum for EM collection, concentration, source/receptor tracking, and targeting. The nonimaging modular optical system uses a physically static position aperture for EM radiation collection. Folded optics provide the concentration of the radiation and source autotracking. The collected and concentrated electromagnetic radiation is utilized in many applications, e.g., solar spectrum in thermal and associative photon bombardment applications for hazardous waste management, water purification, metal hardening, hydrogen generation, photovoltaics, etc., in both space and terrestrial segment utilization. Additionally, at the high end of the concentration capability range, i.e., 60,000+, a solar-pulsed laser system is possible.

  16. Coupling of an applied field magnetically insulated ion diode to a high power magnetically insulated transmission line system

    International Nuclear Information System (INIS)

    Maenchen, J.E.

    1983-01-01

    The coupling of energy from a high power pulsed accelerator through a long triplate magnetically insulated transmission line (MITL) in vacuum to an annular applied magnetic field insulated extraction ion diode is examined. The narrow power transport window and the wave front erosion of the MITL set stringent impedance history conditions on the diode load. A new ion diode design developed to satisfy these criteria with marginal electron insulation is presented. The LION accelerator is used to provide a positive polarity 1.5 MV, 350 kA, 40 ns FWHM pulse with a 30 kA/ns current rate from a triplate MITL source. A transition converts the triplate into a cylindrical cross section which flares into the ion diode load. Extensive current and voltage measurements performed along this structure and on the extracted ion beam provide conclusive evidence that the self insulation condition of the MITL is maintained in the transition by current loss alone. The ion diode utilizes a radial magnetic field between a grounded cathode annular emission tip and a disk anode. A 50 cm 2 dielectric/metal anode area serves as the ion plasma source subject to direct electron bombardment from the opposing cathode tip under marginal magnetic insulation conditions. The ions extracted cross the radial magnetic field and exit the diode volume as an annular cross section beam of peak current about 100 kA. The diode current gradually converts from the initial electron flow to nearly 100% ion current after 30 ns, coupling 60% of the diode energy into ions

  17. Vacuum insulation - Panel properties and building applications. HiPTI - High Performance Thermal Insulation - IEA/ECBCS Annex 39 - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Erb, M. (ed.)

    2005-12-15

    This paper takes a look at the properties of vacuum insulation panels (VIP) that have already been developed some time ago for use in appliances such as refrigerators and deep-freezers. Their insulation performance is a factor of five to ten times better than that of conventional insulation. The paper discusses the use of such panels in buildings to provide thin, highly-insulating constructions for walls, roofs and floors. The motivation for examining the applicability of high performance thermal insulation in buildings is discussed, including solutions where severe space limitations and other technical and aesthetic considerations exist. The use of nano-structured materials and laminated foils is examined and discussed. The questions arising from the use of such panels in buildings is discussed and the open questions and risks involved are examined. Finally, an outlook on the introduction of VIP technology is presented and quality assurance aspects are examined. This work was done within the framework of the Task 39 'High Performance Thermal Insulation' of the 'Energy Conservation in Buildings and Community Systems ECBCS' programme of the International Energy Agency IEA.

  18. 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

  19. 75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

    Science.gov (United States)

    2010-01-12

    ... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...

  20. 21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

  1. DML and Foil Measurements of ETA Beam Radius

    International Nuclear Information System (INIS)

    Nexsen, W; Weir, J

    2005-01-01

    Simultaneous measurements of the ETA beam radius have been made with a quartz foil and a diamagnetic loop (DML). While the measurements agreed at some settings they diverged at others. While the DML measures the rms radius of the total beam, the foil measures mainly the core and the divergence can be explained by the presence of a low density halo. Evidence of such a halo from other measurements is presented

  2. Practical and research aspects of beam-foil spectroscopy

    International Nuclear Information System (INIS)

    Bashkin, S.

    1975-01-01

    The application of a heavy-ion accelerator to research in beam-foil spectroscopy requires certain capital equipment which is somewhat unorthodox when viewed from the standpoint of conventional, low-energy nuclear physics. It is necessary that people who wish to expand their accelerator work to include beam-foil studies understand the nature and cost of such major apparatus. We will survey the equipment needs, starting with the particle analyzer at the output of the accelerator and including the equipment used in a variety of beam-foil experiments. Electronic and computer devices will not be discussed since they are essentially identical with those employed in nuclear studies. Considerable attention will be given to optical spectrometers and spectographs including simple instruments which might be used by a laboratory just getting started in beam-foil research, or which has limited financial resources. Attention will be given to the production and use of the exciter foils. We will then discuss some typical beam-foil experiments having to do with the excitation, detection, and analysis of spectral lines from electronic levels in multiply-ionized atoms, and also with the measurement of the mean lives of such levels. Finally, we will review some of the special properties of the beam-foil light source as regards the population of the magnetic sub-states of a given level. Recent work on the character of the emitted light will be presented. That work will deal specifically with the origin of the polarization of the light. The relevant experiments involve varying the angle between the plane of the exciter foil and the particle velocity. (author)

  3. Alignment and orientation effects in beam-foil experiments

    International Nuclear Information System (INIS)

    Band, Y.B.

    1975-01-01

    A theory of the orientation and alignment of atoms observed upon emergence from tilted foils is presented. The interaction with the foil surface is taken into account in the production process of particular states. Once they are produced, the evolution of these states, under the influence of the residual field near the surface, is calculated in the fashion introduced by Eck. The most general effect of this evolution is presented

  4. 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.)

  5. Insulation Reformulation Development

    Science.gov (United States)

    Chapman, Cynthia; Bray, Mark

    2015-01-01

    The current Space Launch System (SLS) internal solid rocket motor insulation, polybenzimidazole acrylonitrile butadiene rubber (PBI-NBR), is a new insulation that replaced asbestos-based insulations found in Space Shuttle heritage solid rocket boosters. PBI-NBR has some outstanding characteristics such as an excellent thermal erosion resistance, low thermal conductivity, and low density. PBI-NBR also has some significant challenges associated with its use: Air entrainment/entrapment during manufacture and lay-up/cure and low mechanical properties such as tensile strength, modulus, and fracture toughness. This technology development attempted to overcome these challenges by testing various reformulated versions of booster insulation. The results suggest the SLS program should continue to investigate material alternatives for potential block upgrades or use an entirely new, more advanced booster. The experimental design was composed of a logic path that performs iterative formulation and testing in order to maximize the effort. A lab mixing baseline was developed and documented for the Rubber Laboratory in Bldg. 4602/Room 1178.

  6. Beyond insulation and isolation

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær

    2016-01-01

    are insulation and isolation strategies to reduce measurable and perceptual noise levels. However, these strategies do not actively support the need to feel like an integral part of the shared hospital environment, which is a key element in creating healing environments, according to the paradigm of Evidence-Based...

  7. Self-Healing Wire Insulation

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2012-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured, reactants within the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  8. Properties of polymer foils used as solid-state track detectors

    International Nuclear Information System (INIS)

    Spurny, F.

    1973-05-01

    Polymer foils were studied with a view to their application as solid-state alpha track detectors. The detection efficiency was determined as was its alpha energy dependence and the quality of the surface and the natural background of the foils were evaluated. The kinetics of etching was studied in three selected type of foils. Characteristic constants for the selected foils and methods of etching were calculated. The possible applications of the foils as track detectors are discussed and the effect is dealt with of the selected foil and of the method of chemical etching on the foil applicability in nuclear sciences, especially in fast neutron dosimetry and in alpha spectrometry. (author)

  9. P-type diamond stripper foils for tandem ion accelerators

    International Nuclear Information System (INIS)

    Phelps, A.W.; Koba, R.

    1989-01-01

    The authors are developing a stripper foil composed of a p-type diamond membrane. This diamond stripper foil should have a significantly longer lifetime than any conventional stripper foil material. To be useful for stripper foils, the boron-doped blue diamond films must be thinner than 0.8 μm and pore-free. Two methods are compared for their ability to achieve a high nucleation areal density on a W substrate. Some W substrates were first coated with think layer of boron (≤20 nm) in order to enhance nucleation. Other W substrates were scratched with submicron diamond particles. A schematic diagram of the stripper foil is shown. Stripper foils were created by etching away the central area of W substrates. The diamond membrane was then supported by an annulus of W. Tungsten was selected as a ring-support material because of its high electrical and thermal conductivity, relatively low thermal expansion, and proven suitability as a substrate for diamond CVD. Warping or fracture of the diamond film after substrate etch-back was investigated

  10. 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

  11. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  12. Design principles for handmade electrical insulation of superconducting joints in W7-X

    Energy Technology Data Exchange (ETDEWEB)

    Rummel, K., E-mail: kerstin.rummel@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); John, A. [Max Planck Institute for Plasma Physics, EURATOM Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Sulek, Z. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Radzikowskiego 152 (Poland)

    2013-10-15

    Highlights: ► In W-7X there are several types of handmade electrical insulation. ► In general insulation based on impregnated glass tapes and special G10 pieces. ► A proper overlapping of glass tapes turned out to be mandatory. ► Detailed qualification and training helps to minimize the failure rate. ► Visual inspection and Paschen tests after every insulation steps are important. -- Abstract: The superconducting magnet system of the Wendelstein 7-X (W7-X) experiment consists of 50 non-planar and 20 planar coils, 121 bus bars and 14 current leads. The connection between bus bars, coils and current leads will be provided by 198 joints. The joints have to be insulated manually during the assembly of the machine in constraint positions and a tight environment. In general the insulation is based on glass tapes impregnated with epoxy resin and special G10 insulating pieces embedded in the glass tape insulation. In critical areas Kapton{sup ®}-foils are embedded in the insulation. All types of insulation were qualified at mock-ups in a 1:1 model of the expected environment in W7-X. The qualification programme comprises thermal cycling between room temperature and 77 K and high voltage tests under air, under vacuum and under reduced pressure (Paschen test). The paper describes the main principles used for different types of handmade Paschen-tight insulations in W7-X and the visual and electrical tests during and after assembly.

  13. Effect of spacers on the thermal performance of an annular multi-layer insulation

    International Nuclear Information System (INIS)

    Haim, Y.; Weiss, Y.; Letan, R.

    2014-01-01

    The current study presents a model and is experimentally conducted in a system of 40 stainless steel coaxial foils, of nitrogen gas, entrapped between the foils, and of spacers, which are zirconia, spherical, 50 μm in size particles, widely dispersed in the gaps between the foils. The model, experimentally verified, relates to radiation between the foils, unobstructed by particles, to conduction in the nitrogen gas, and to conduction across the particles. The study was, in particular, aimed to measure the effective thermal conductivity of the particles and to assess its effect upon the array. At vacuum of 0.092 Pa, the effective thermal conductivity of the particles was 2.13 × 10 −4  W/m K, while the effective thermal conductivity of the array was 4.74 × 10 −4  W/m K. Thus, the low contribution of the particles conduction at vacuum conditions improves the insulation. It reaches 45% of the heat transfer rate. At atmospheric pressure, the effective thermal conductivity of the array reaches 4.5 × 10 −2  W/m K. There, the spacers contribution is negligible. - Highlights: •The multi-layer insulation of cylinder consists of foils separated by particles. •The particles are widely spaced in gaps. •Particles heat transfer rate is almost half of the total in vacuum. •At higher pressures the particles contribution is negligible. •The predicted thermal performance agrees with experimental results

  14. Health status of cows fed maize silage covered with oxo-biodegradable foil

    OpenAIRE

    Piotr SZTERK; Piotr DORSZEWSKI; Małgorzata GRABOWICZ; Lucyna PODKÓWKA

    2017-01-01

    In agricultural practice, silage production uses pure, low density polyethylene foil. This foil, after use, becomes farm waste, having a negative impact on the environment. Instead of conventional foil, an environmentally safe biodegradable foil can be used, made from naturally occurring polymers or from synthetic multiparticulates, easily degradable by microorganisms. Silage covered with this type of foil should be safe for animal health. The purpose of the study was to determine whether oxo...

  15. Metal-insulator transitions

    Science.gov (United States)

    Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori

    1998-10-01

    Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject. Especially important are the transitions driven by correlation effects associated with the electron-electron interaction. The insulating phase caused by the correlation effects is categorized as the Mott Insulator. Near the transition point the metallic state shows fluctuations and orderings in the spin, charge, and orbital degrees of freedom. The properties of these metals are frequently quite different from those of ordinary metals, as measured by transport, optical, and magnetic probes. The review first describes theoretical approaches to the unusual metallic states and to the metal-insulator transition. The Fermi-liquid theory treats the correlations that can be adiabatically connected with the noninteracting picture. Strong-coupling models that do not require Fermi-liquid behavior have also been developed. Much work has also been done on the scaling theory of the transition. A central issue for this review is the evaluation of these approaches in simple theoretical systems such as the Hubbard model and t-J models. Another key issue is strong competition among various orderings as in the interplay of spin and orbital fluctuations. Experimentally, the unusual properties of the metallic state near the insulating transition have been most extensively studied in d-electron systems. In particular, there is revived interest in transition-metal oxides, motivated by the epoch-making findings of high-temperature superconductivity in cuprates and colossal magnetoresistance in manganites. The article reviews the rich phenomena of anomalous metallicity, taking as examples Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Ru compounds. The diverse phenomena include strong spin and

  16. A Microfabricated Involute-Foil Regenerator for Stirling Engines

    Science.gov (United States)

    Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Qiu, Songgang

    2007-01-01

    A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C

  17. Efficient and rapid C. elegans transgenesis by bombardment and hygromycin B selection.

    Directory of Open Access Journals (Sweden)

    Inja Radman

    Full Text Available We report a simple, cost-effective, scalable and efficient method for creating transgenic Caenorhabditis elegans that requires minimal hands-on time. The method combines biolistic bombardment with selection for transgenics that bear a hygromycin B resistance gene on agar plates supplemented with hygromycin B, taking advantage of our observation that hygromycin B is sufficient to kill wild-type C. elegans at very low concentrations. Crucially, the method provides substantial improvements in the success of bombardments for isolating transmitting strains, the isolation of multiple independent strains, and the isolation of integrated strains: 100% of bombardments in a large data set yielded transgenics; 10 or more independent strains were isolated from 84% of bombardments, and up to 28 independent strains were isolated from a single bombardment; 82% of bombardments yielded stably transmitting integrated lines with most yielding multiple integrated lines. We anticipate that the selection will be widely adopted for C. elegans transgenesis via bombardment, and that hygromycin B resistance will be adopted as a marker in other approaches for manipulating, introducing or deleting DNA in C. elegans.

  18. 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

  19. BANGERTER FOILS IN THE POSTOPERATIVE MANAGEMENT OF ESOTROPIA.

    Directory of Open Access Journals (Sweden)

    Galina G. Dimitrova

    2014-12-01

    Full Text Available Purpose: To evaluate the application of Bangerter foils in the postoperative management of esotropia Methods: A retrospective study of 200 patients who underwent bimedial recessions for various forms of alternating/alternated esotropia in the period of 2000-2013. In the cases of residual postoperative angle, tendency of recurrence of strabismus and preferred fixation, Bangerter foil was fixed on the corrective glass of the dominant eye- either on the next day of surgery, or on the 10-th postoperative day and was in use for at least 6 months. Results: Bangerter foils were applied in 67(35,1% under corrected patients with a mean residual angle for near 7,01±3,51Δ. Mean residual angle in patients without foils was 3,47±4,06Δ (p<0,001. Statistically significant factors in patients with filters were amblyopia treatment before surgery (p<0,001, anisometropia (p=0,003 and type of esotropia (accommodative vs. non accommodative (p<0,001. Within the group without filters there was a significant increase of the residual angle for near on the third (p<0,001 and sixth month (p=0,036, while within the group with foils angle was not significantly changed (p=0,325; p=0,058 with time. In the group with foils no cases with relapse of strabismus and amblyopia were recorded and even a decrease of the postoperative angle was clinically observed in some patients. Conclusion: To our experience Bangerter foils are a reliable tool in the postoperative management of undercorrected esotropia.

  20. Heat insulating plates

    Energy Technology Data Exchange (ETDEWEB)

    Allan, J.A.F.

    1976-10-28

    Micro-porous insulation plates are dealt with, for example, how they are used in the insulation of heat storage devices. Since one side of such plates is exposed to a temperature of over 700/sup 0/C, a shrinkage of the glass texture of the covering can occur, which can exceed the shrinkage of the inner micro-porous material, so that cracks and splits in the high temperature side of the covering can come about. The task of the invention is to design the plate in such a way as to prevent this from happening. For this purpose the plate is provided, according to invention specifications, with flutes, waves, ribs, waffle or grid patterns and the covering is set into the recesses originating from this.

  1. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  2. Compact vacuum insulation embodiments

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  3. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  4. Insulating materials for optoelectronics

    International Nuclear Information System (INIS)

    Agullo-Lopez, F.

    1990-01-01

    Optoelectronics is an interdisciplinary field. Basic functions of an optoelectronic system include the generator of the optical signal, its transmission and handling and, finally, its detection, storage and display. A large variety of semiconductor and insulating materials are used or are being considered to perform those functions. The authors focus on insulating materials, mostly oxides. For signal generation, tunable solid state lasers, either vibronic or those based oon colour centres are briefly described, and their main operating parameters summarized. Reference is made to some developments on fiber and waveguide lasers. Relevant physical features of the silica fibres used for low-loss, long-band, optical transmission are reviewed, as well as present efforts to further reduce attenuation in the mid-infrared range. Particular attention is paid to photorefractive materials (LiNbO 3 , BGO, BSO, etc.), which are being investigated

  5. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties......Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  6. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  7. Transient and steady state behaviour of elasto–aerodynamic air foil bearings, considering bump foil compliance and top foil inertia and flexibility: A numerical investigation

    DEFF Research Database (Denmark)

    Nielsen, Bo Bjerregaard; Santos, Ilmar F.

    2017-01-01

    utilise two types of eight-node isoparametric elements. The rotor is modelled as a rigid body without rotational inertia, i.e. as a journal. The bump foil is included via a bilinear version of the simple elastic foundation model. This paper introduces the bilinear simple elastic foundation model, which...

  8. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  9. Pourable Foam Insulation

    Science.gov (United States)

    Harvey, James A.; Butler, John M.; Chartoff, Richard P.

    1989-01-01

    Report describes search for polyisocyanurate/polyurethane foam insulation with superior characteristics. Discusses chemistry of current formulations. Tests of formulations, of individual ingredients and or alternative new formulations described. Search revealed commercially available formulations exhibiting increased thermal stability at temperatures up to 600 degree C, pours readily before curing, presents good appearance after curing, and remains securely bonded to aluminum at cryogenic temperatures. Total of 42 different formulations investigated, 10 found to meet requirements.

  10. Direct and Recoil-Induced Electron Emission from Ion-Bombarded Solids

    DEFF Research Database (Denmark)

    Holmen, G.; Svensson, B.; Schou, Jørgen

    1979-01-01

    The kinetic emission of secondary electrons from ion-bombarded solid surfaces is split into two contributions, a direct one caused by ionizing collisions between the bombarding ion and target atoms, and an indirect one originating from ionizing collisions undergone by recoil atoms with other target...... atoms. The direct contribution, which has been treated by several authors in previous studies, shows a behavior that is determined primarily by the electronic stopping power of the bombarding ion, while the indirect contribution is nonproportionally related to the nuclear stopping power. This latter...

  11. Topography of InP surface bombarded by O2+ ion beam

    International Nuclear Information System (INIS)

    Sun Zhaoqi

    1997-01-01

    The topography of InP surface bombarded by O 2 + ion beam was investigated. Rippled topographies were observed for bombarded samples, and the data show that the ripple formation starts from a sputtering depth of about 0.4 μm. The wavelength and the disorder of the ripples both increase as the sputtering depth increases. The wavelength of the ripples appears to be sputtering depth dependent rather than sputtering rate dependent. It is confirmed that the ion-beam-induced surface rippling can be effectively suppressed by sample rotation during bombardment

  12. Effect of the ion bombardment on the apparent barrier height in GaAs Schottky junctions

    International Nuclear Information System (INIS)

    Horvath, Zs. J.

    1994-01-01

    The bombardment of the semiconductor with different particles often results in the change of the doping concentration at the semiconductor surface. In this paper the effects of this near-interface concentration change on the apparent and real Schottky barrier heights are discussed. Experimental results obtained in GaAs Schottky junctions prepared on ion-bombarded semiconductor surfaces are analysed, and it is shown that their electrical characteristics are strongly influenced by the near-interface concentration change due to the ion bombardment. (author). 36 refs., 2 figs

  13. Preliminary report into the effects of nitrogen ion bombardment treatment on mustard seeds

    International Nuclear Information System (INIS)

    Smith, C.W.; Al-Hashmi, S.A.R.; Ahmed, N.A.G.; Pollard, M.

    1988-01-01

    Mustard seeds have been subjected to nitrogen ion bombardment. A range of conditions was found within which there was an enhancement in the growth of seedlings from the ion bombardment treated seeds relative to those grown from control seeds. Scanning electron microscopy was used to examine seeds after treatment. It appeared that there had been an etching of the seed coating by the ion bombardment. This view was supported by experiments which showed that the rate of capillary water uptake by the treated seeds had been enhanced. (author)

  14. Selecting foils for identification lineups: matching suspects or descriptions?

    Science.gov (United States)

    Tunnicliff, J L; Clark, S E

    2000-04-01

    Two experiments directly compare two methods of selecting foils for identification lineups. The suspect-matched method selects foils based on their match to the suspect, whereas the description-matched method selects foils based on their match to the witness's description of the perpetrator. Theoretical analyses and previous results predict an advantage for description-matched lineups both in terms of correctly identifying the perpetrator and minimizing false identification of innocent suspects. The advantage for description-matched lineups should be particularly pronounced if the foils selected in suspect-matched lineups are too similar to the suspect. In Experiment 1, the lineups were created by trained police officers, and in Experiment 2, the lineups were constructed by undergraduate college students. The results of both experiments showed higher suspect-to-foil similarity for suspect-matched lineups than for description-matched lineups. However, neither experiment showed a difference in correct or false identification rates. Both experiments did, however, show that there may be an advantage for suspect-matched lineups in terms of no-pick and rejection responses. From these results, the endorsement of one method over the other seems premature.

  15. Dosimetric response of united, commercially available CTA foils for sup 6 sup 0 Co gamma rays

    CERN Document Server

    Peimel-Stuglik, Z

    2001-01-01

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for sup 6 sup 0 Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for sup 6 sup 0 Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life.

  16. Dosimetric response of united, commercially available CTA foils for 60Co gamma rays

    International Nuclear Information System (INIS)

    Peimel-Stuglik, Z.

    2001-01-01

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for 60 Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for 60 Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life. (author)

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

    Science.gov (United States)

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

    2016-07-13

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

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

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    2016-07-01

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

  19. Electrochemically assisted fast-atom-bombardment mass spectrometry

    International Nuclear Information System (INIS)

    Phillips, L.R.

    1988-01-01

    The hybridization of electrochemistry and fast atom bombardment (FAB) mass spectrometry (MS) creates a new hyphenated technique, referred to as electrochemically assisted FAB (EFAB) MS, which improves the applicability of FAB MS in selectivity and extends the range of compounds to include low polarity molecules, and also reduces mass spectral complications due to matrix-related artifacts. FAB MS has proven to be indispensable in analysis of samples that are otherwise too intractable for conventional MS, such as peptides, oligosaccharides, and oligonucleotides, due to low volatility and ready thermal degradation. There are limits on its applicability, however, in that it works best with samples that are already ionic, or predisposed to become so by simple proton transfer to or from the matrix. A wide range of chemical substances can be ionized/analyzed by electrochemical methods. Therefore, a possible approach towards improving applicability of FAB MS is through its hybridization with electrochemistry. Samples are activated by electrolysis, carried out directly in the sample matrix through use of a modified FAB sample probe which was constructed containing a small electrolytic cell on the tip. In operation, one electrode is held at normal sample-probe/ion-source voltage, while the other electrode can be continuously varied ±15 volts to create electrochemical potentials. Several chemical substances, known to be unresponsive to FAB MS, have been examined by EFAB MS. Resultant spectra generally show a dramatic increases in signal/chemical noise ratio of structurally significant ions when compared to normal FAB spectra

  20. Annealing of defects in indium antimonide after ion bombardment

    International Nuclear Information System (INIS)

    Bogatyrev, V.A.; Kachurin, G.A.

    1977-01-01

    Indium antimonide electric properties are investigated after ion bombardment of different mass (with energy of 60 and 300 keV) and isochrone annealing in the 20-450 deg C temperature range. It is shown that 100-150 deg C n- type stable layers are formed after proton irradiation at room temperature only. Indium antimonide exposure by average mass ions under the same conditions and also by helium ions of 300 keV energy brings to p-type layer formation with high hole concentration. Subsequent heating at the temperature over 150 deg C results in electron conductivity of irradiated layers. Electron volume density and mobility efficiency reaches 10 18 cm -3 and 10 4 cm 2 /Vs respectively. N-type formed layers are stable up to 350 deg C allowing its usage for n-p transition formation admitting thermal treatment. Analysis is given of defect behaviour peculiarities depending upon the irradiation and annealing conditions. Hole conductivity in irradiated indium antimonide is supposed to be stipulated by regions of disorder, while electron conductivity - by relatively simpler disorders

  1. Actinide production from xenon bombardments of curium-248

    International Nuclear Information System (INIS)

    Welch, R.B.

    1985-01-01

    Production cross sections for many actinide nuclides formed in the reaction of 129 Xe and 132 Xe with 248 Cm at bombarding energies slightly above the coulomb barrier were determined using radiochemical techniques to isolate these products. These results are compared with cross sections from a 136 Xe + 248 Cm reaction at a similar energy. When compared to the reaction with 136 Xe, the maxima in the production cross section distributions from the more neutron deficient projectiles are shifted to smaller mass numbers, and the total cross section increases for the production of elements with atomic numbers greater than that of the target, and decreases for lighter elements. These results can be explained by use of a potential energy surface (PES) which illustrates the effect of the available energy on the transfer of nucleons and describes the evolution of the di-nuclear complex, an essential feature of deep-inelastic reactions (DIR), during the interaction. The other principal reaction mechanism is the quasi-elastic transfer (QE). Analysis of data from a similar set of reactions, 129 Xe, 132 Xe, and 136 Xe with 197 Au, aids in explaining the features of the Xe + Cm product distributions, which are additionally affected by the depletion of actinide product yields due to deexcitation by fission. The PES is shown to be a useful tool to predict the general features of product distributions from heavy ion reactions

  2. A molecular dynamics study of energetic particle bombardment on diamond

    International Nuclear Information System (INIS)

    Li Rongbin; Dai Yongbing; Hu Xiaojun; Shen Hesheng; He Xianchang

    2003-01-01

    Molecular dynamic simulations, utilizing the Tersoff many-body potential, are used to investigate the microscopic processes of a single boron atom with an energy of 500 eV implanted into the diamond (001) 2 x 1 reconstructed surface. By calculating the variation of the mean coordination number with time, the lifetime of a thermal spike created by B bombardment is about 0.18 ps. Formation of the split-interstitial composed of projectile and lattice atom (B-C) is observed. The total potential energy of the system decreases about 0.56 eV with a stable B split-interstitial existing in diamond. Lattice relaxations in the diamond (001) 2 x 1 reconstructed surface or near surface of the simulated have been discussed, and the results show that the outermost layer atoms tend to move inward and other atoms move outward, while the interplanar distance between the outermost layer and the second layer has been shortened by 15%, compared with its starting interplanar distance. Stress distribution in the calculated diamond configuration is inhomogeneous. After boron implanted into diamond with an energy of 500 eV, there is an excess of compressively stressed atoms in the lattice, which induces the total stress being compressive

  3. Sputtering and reflection of self-bombardment of tungsten material

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Guo-jian [University of Science and Technology of China, Hefei (China); Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Li, Xiao-chun; Xu, Qian; Yang, Zhong-shi [Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Luo, Guang-nan, E-mail: gnluo@ipp.ac.cn [University of Science and Technology of China, Hefei (China); Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of CAS, Hefei (China)

    2015-04-15

    In present research, the sputtering and reflection yield of self-bombardment of tungsten are investigated with the aid of molecular dynamics simulations. The source of sputtered and reflected atoms is detected by traced the original locations of sputtered and reflected atoms. Results show that for the reflected atoms no specific region exists which means cluster atoms are randomly reflected. But almost all of sputtered atoms are from a conical region under the landing point of cluster. So we can determine the sputtering yield by study the dimension of the sputtering region. Molecular dynamics shows the depth and radius of the conical are power functions of impacting energy. The effects of cluster size and temperature of target on sputtering and reflection rate are also preformed in present study. Both sputtering and reflection yield are proportion to cluster size in present cluster size, i.e. 66–2647 atoms. Higher target temperature can increase sputtering yield and deduce sputtering threshold energy, but little effect on reflection rate.

  4. Auger emission from solid surfaces bombarded with ions

    International Nuclear Information System (INIS)

    Grizzi, Oscar.

    1986-01-01

    The Auger electron emission from Be, Na, Mg, Al and Si bombarded with 0,5-20 KeV noble gas ions is studied. Sharp structures of the Auger electron spectra of Na and Be were identified. A Monte Carlo program was adapted to simulate the colision cascade in the solid, inner shell excitations and Auger decays. From the comparision of experimental and simulated Auger intensities, the relative role of symmetric and asymmetric collisions in Be K- and Al L-shell excitation were evaluated. In the case of Be, the discussion of the exciting processes to higher projectile energies was extended. To this end, the simulation to early measurements of Be K X-ray yields was applied. From this analysis, information about the variations of the fluorescence yield and outer-shell occupation numbers of Be with projectile energy was obtained. The study of the shape of the sharp Auger structures and their dependence with the energy and incidence projectile angle gives information about the collisional processes, inner hole lifetimes and Auger decays. From the evaluation of the energy and angular distribution of the excited sputtered atoms and the interaction between them and the metallic-surface, the energy shift distributions in the Auger energies were obtained. From the comparison of these distributions with the experimental atomic peaks, the main causes of the broadening of these peaks were determined. (M.E.L.) [es

  5. Modelling and simulation of surface morphology driven by ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Yewande, E.O.

    2006-05-02

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  6. Sputtering and reflection of self-bombardment of tungsten material

    International Nuclear Information System (INIS)

    Niu, Guo-jian; Li, Xiao-chun; Xu, Qian; Yang, Zhong-shi; Luo, Guang-nan

    2015-01-01

    In present research, the sputtering and reflection yield of self-bombardment of tungsten are investigated with the aid of molecular dynamics simulations. The source of sputtered and reflected atoms is detected by traced the original locations of sputtered and reflected atoms. Results show that for the reflected atoms no specific region exists which means cluster atoms are randomly reflected. But almost all of sputtered atoms are from a conical region under the landing point of cluster. So we can determine the sputtering yield by study the dimension of the sputtering region. Molecular dynamics shows the depth and radius of the conical are power functions of impacting energy. The effects of cluster size and temperature of target on sputtering and reflection rate are also preformed in present study. Both sputtering and reflection yield are proportion to cluster size in present cluster size, i.e. 66–2647 atoms. Higher target temperature can increase sputtering yield and deduce sputtering threshold energy, but little effect on reflection rate

  7. Fast atom bombardment tandem mass spectrometry of carotenoids

    Energy Technology Data Exchange (ETDEWEB)

    van Breeman, R.B. [Univ. of Illinois, Chicago, IL (United States); Schmitz, H.H.; Schwartz, S.J. [North Carolina State Univ., Raleigh, NC (United States)

    1995-02-01

    Positive ion fast atom bombardment (FAB) tandem mass spectrometry (MS-MS) using a double-focusing mass spectrometer with linked scanning at constant B/E and high-energy collisionally activated dissociation (CAD) was used to differentiate 17 different cartenoids, including {beta}-apo-8{prime}- carotenal, astaxanthin, {alpha}-carotene, {beta}-carotene, {gamma}-carotene, {zeta}-carotene, canthaxanthin, {beta}-cryptoxanthin, isozeaxanthin bis (pelargonate), neoxanthin, neurosporene, nonaprene, lutein, lycopene, phytoene, phytofluene, and zeaxanthin. The carotenoids were either synthetic or isolated from plant tissues. The use of FAB ionization minimized degradation or rearrangement of the carotenoid structures due to the inherent thermal instability generally ascribed to these compounds. Instead of protonated molecules, both polar xanthophylls and nonpolar carotenes formed molecular ions, M{sup {center_dot}+}, during FAB ionization. Following collisionally activated dissociation, fragment ions of selected molecular ion precursors showed structural features indicative of the presence of hydroxyl groups, ring systems, ester groups, and aldehyde groups and the extent of aliphatic polyene conjugation. The fragmentation patterns observed in the mass spectra herein may be used as a reference for the structural determination of carotenoids isolated from plant and animal tissues. 18 refs., 4 figs.

  8. Impact of Ion Bombardment on the Structure and Magnetic Properties of Fe78Si13B9 Amorphous Alloy

    Science.gov (United States)

    Wu, Yingwei; Peng, Kun

    2018-06-01

    Amorphous Fe78Si13B9 alloy ribbons were bombarded by ion beams with different incident angles ( θ ). The evolution of the microstructure and magnetic properties of ribbons caused by ion beam bombardment was investigated by x-ray diffraction, transmission electron microscope and vibrating sample magnetometer analysis. Low-incident-angle bombardment led to atomic migration in the short range, and high-incident-angle bombardment resulted in the crystallization of amorphous alloys. Ion bombardment induces magnetic anisotropy and affects magnetic properties. The effective magnetic anisotropy was determined by applying the law of approach to saturation, and it increased with the increase of the ion bombardment angle. The introduction of effective magnetic anisotropy will reduce the permeability and increase the relaxation frequency. Excellent high-frequency magnetic properties can be obtained by selecting suitable ion bombardment parameters.

  9. Reduction of heat insulation upon soaking of the insulation layer

    Science.gov (United States)

    Achtliger, J.

    1983-09-01

    Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

  10. 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.)

  11. 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.

  12. Development of single mask GEM foils in India

    International Nuclear Information System (INIS)

    Pant, L.M.; Mohanty, A.K.; Pinto, O.J.; Gadhadharan, S.; Menon, Pradeep; Sharma, Archana; Oliveira, Rui De; )

    2014-01-01

    There are various techniques available around the globe for making punch through holes for Micro Pattern Gas Detectors (MPGDs), such as Gas Electron Multipliers (GEMs). The GEM foils consists of 5 μm of Cu clad on both the sides of 50 μm polymide (PMMA/kapton) (5/50/5). At present these foils are developed in South Korea without having any adhesive between the Cu and polymide. The available techniques range from chemical etching, reactive plasma etching and laser etching. However, for GEM detectors, having an active area upto 5000 cm 2 , the chemical etching process using a Single Mask has been developed at CERN which is faster from the viewpoint of mass production of such foils for the upgrades which are foreseen in a couple of years with the Large Hadron Collider facility at CERN

  13. Foil Bearing Coating Behavior in CO2

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Matthew [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kruizenga, Alan Michael [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Pasch, James Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fleming, Darryn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The Sandia S-CO2 Recompression Closed Brayton Cycle (RCBC) utilizes a series of gas foil bearings in its turbine-alternator-compressors. At high shaft rotational speed these bearings allow the shaft to ride on a cushion of air. Conversely, during startup and shutdown, the shaft rides along the foil bearing surface. Low-friction coatings are used on bearing surfaces in order to facilitate rotation during these periods. An experimental program was initiated to elucidate the behavior of coated bearing foils in the harsh environments of this system. A test configuration was developed enabling long duration exposure tests, followed by a range of analyses relevant to their performance in a bearing. This report provides a detailed overview of this work. The results contained herein provide valuable information in selecting appropriate coatings for more advanced future bearing-rig tests at the newly established test facility in Sandia-NM.

  14. Effects of film/foil interactions on X-ray image quality - experimental studies

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1985-01-01

    When assessing the quality of X-ray images, the interaction between film and foil should never be left out of account. Except for the case of green-emitting foils which require green-emitting films, films and foils are normally regarded separately, so that many variations are possible. The authors review the interaction between film and foil under practical aspects. Studies published so far have concentrated either on the amplification factor of foils or an the object imaging characteristics of certain films. Systematic studies on the interaction between film and foil have never been carried out. (orig.) [de

  15. Ion peening and stress relaxation induced by low-energy atom bombardment of covalent solids

    International Nuclear Information System (INIS)

    Koster, Monika; Urbassek, Herbert M.

    2001-01-01

    Using molecular-dynamics simulation, we study the buildup and relaxation of stress induced by low-energy (≤150 eV) atom bombardment of a target material. The effect is brought out most clearly by using an initially compressed specimen. As target material, we employ Si, based on the Tersoff potential. By varying the bond strength in the potential, we can specifically study its effect on damage production and stress changes. We find that in general, stress is relaxed by the atom bombardment; only for low bombarding energies and strong bonds, atom bombardment increases stress. We rationalize this behavior by considering the role of energized atoms and of recoil-implanted target atoms

  16. The interpretation of ellipsometric measurements of ion bombardment of noble gases on semiconductor surfaces

    NARCIS (Netherlands)

    Holtslag, A.H.M.; Slager, U.C.; van Silfhout, Arend

    1985-01-01

    Low energy noble gas ion bombardment and thermal desorption studies were carried out on Si(111) and analysed, in situ, using spectroscopic ellipsometry. The amorphous layer thickness and implanted noble gas fraction were calculated.

  17. Self-Assembled Gold Nano-Ripple Formation by Gas Cluster Ion Beam Bombardment.

    Science.gov (United States)

    Tilakaratne, Buddhi P; Chen, Quark Y; Chu, Wei-Kan

    2017-09-08

    In this study, we used a 30 keV argon cluster ion beam bombardment to investigate the dynamic processes during nano-ripple formation on gold surfaces. Atomic force microscope analysis shows that the gold surface has maximum roughness at an incident angle of 60° from the surface normal; moreover, at this angle, and for an applied fluence of 3 × 10 16 clusters/cm², the aspect ratio of the nano-ripple pattern is in the range of ~50%. Rutherford backscattering spectrometry analysis reveals a formation of a surface gradient due to prolonged gas cluster ion bombardment, although the surface roughness remains consistent throughout the bombarded surface area. As a result, significant mass redistribution is triggered by gas cluster ion beam bombardment at room temperature. Where mass redistribution is responsible for nano-ripple formation, the surface erosion process refines the formed nano-ripple structures.

  18. Design and Operation of a Calorimeter for Advanced Multilayer Insulation Testing

    Science.gov (United States)

    Chato, David; Johnson, Wesley; Dresar, Neil Van

    2016-01-01

    A calorimeter has been constructed to accurately measure insulation performance with a nominal 90K cold outer boundary and a 20K inner boundary. Unique features of this design include use of mechanical cryocoolers instead cryogens and measurement of the heat load with a calibrated rod to serve as a conduction path. The calorimeter is operational and has completed its first test series. The initial test series was designed to look for differences in performance between a single layer of aluminum foil and a sheet of double aluminized mylar (DAM). Although it has been speculated that the aluminum foil would perform better, since the mylar coating might not thick enough to stop the transmission of long wave length infrared radiation, our testing showed a higher heat load for the aluminum foil than the DAM. The aluminum foil showed a heat load of 132 mW at an 87 K outer temperature and 152 mW at a 107K outer temperature. Whereas the DAM showed a heat load of 66 mW at an 88 K outer temperature and 81 mW at 108 K.

  19. Electrical insulating liquid: A review

    Directory of Open Access Journals (Sweden)

    Deba Kumar Mahanta

    2017-08-01

    Full Text Available Insulating liquid plays an important role for the life span of the transformer. Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and cooling properties. However, the usage of petroleum-based mineral oil, derived from a nonrenewable energy source, has affected the environment for its nonbiodegradability property. Therefore, researchers direct their attention to renewable and biodegradable alternatives. Palm fatty acid ester, coconut oil, sunflower oil, etc. are considered as alternatives to replace mineral oil as transformer insulation liquid. This paper gives an extensive review of different liquid insulating materials used in a transformer. Characterization of different liquids as an insulating material has been discussed. An attempt has been made to classify different insulating liquids-based on different properties.

  20. Particle-In-Cell/Monte Carlo Simulation of Ion Back Bombardment in Photoinjectors

    International Nuclear Information System (INIS)

    Qiang, Ji; Corlett, John; Staples, John

    2009-01-01

    In this paper, we report on studies of ion back bombardment in high average current dc and rf photoinjectors using a particle-in-cell/Monte Carlo method. Using H 2 ion as an example, we observed that the ion density and energy deposition on the photocathode in rf guns are order of magnitude lower than that in a dc gun. A higher rf frequency helps mitigate the ion back bombardment of the cathode in rf guns

  1. The effects of thermal annealing on iron bombarded InP/InGaAs multilayer structures

    International Nuclear Information System (INIS)

    Subramaniam, S.C.; Rezazadeh, A.A.

    2006-01-01

    The effects of Fe-ion bombardment at 77 K (cold) and room temperature (RT) into single layer InGaAs, InP and multilayer InP/InGaAs HBT structures have been investigated. Annealing characteristics and RF dissipation loss measurements of Fe-ion bombarded samples at 77 K indicated good electrical isolation in n-, p-type InGaAs materials and InP/InGaAs HBT structures. Thermally stable (up to 250 deg. C) high sheet resistance (R sh ) of ∼5 x 10 6 Ω/sq has been achieved on these samples while higher R sh of ∼10 7 Ω/sq was obtained for the n-InP materials bombarded with similar conditions. Dissipation losses of 1.7 dB/cm at 10 GHz and 2.8 dB/cm at 40 GHz have been measured for the cold Fe-ion bombarded InP-based HBT structures. This result is similar to those obtained for an un-bombarded S.I. InP substrate, indicating good electrical isolation. We have also determined electron trapping levels by thermal annealing for the cold and RT Fe-ion bombarded samples. It is shown that the high resistivity achieved in the cold implanted InGaAs layer is most likely due to the creation of mid-bandgap defect levels (E C - 0.33) eV, which are created only in the cold Fe-ion bombardment. The DC isolation and RF dissipation loss analysis have been used to identify a suitable bombardment scheme for the fabrication of planar InP/InGaAs HBTs

  2. Electrochemically replicated smooth aluminum foils for anodic alumina nanochannel arrays

    International Nuclear Information System (INIS)

    Biring, Sajal; Tsai, K-T; Sur, Ujjal Kumar; Wang, Y-L

    2008-01-01

    A fast electrochemical replication technique has been developed to fabricate large-scale ultra-smooth aluminum foils by exploiting readily available large-scale smooth silicon wafers as the masters. Since the adhesion of aluminum on silicon depends on the time of surface pretreatment in water, it is possible to either detach the replicated aluminum from the silicon master without damaging the replicated aluminum and master or integrate the aluminum film to the silicon substrate. Replicated ultra-smooth aluminum foils are used for the growth of both self-organized and lithographically guided long-range ordered arrays of anodic alumina nanochannels without any polishing pretreatment

  3. Compliant Foil Journal Bearings - Investigation of Dynamic Properties

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Santos, Ilmar

    . The influence of explicit and implicit boundary conditions are also investigated. Theoretical results for pressures, shaft equilibrium positions and film thickness are presented and compared to experimental results [17, 19]. A good agreement between experimental and theoretical results are found for large loads....../compliance of the foil structure is presented. The compliance of the foil structure is incorporated implicitly in the Reynolds equation which is accomplished through a modification of the film gap function [8]. The resulting non-linear equation is perturbed and solved by use of the finite element method following...

  4. 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.)

  5. 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

  6. Very low-energy and low-fluence ion beam bombardment of naked plasmid DNA

    International Nuclear Information System (INIS)

    Norarat, R.; Semsang, N.; Anuntalabhochai, S.; Yu, L.D.

    2009-01-01

    Ion beam bombardment of biological organisms has been recently applied to mutation breeding of both agricultural and horticultural plants. In order to explore relevant mechanisms, this study employed low-energy ion beams to bombard naked plasmid DNA. The study aimed at simulation of the final stage of the process of the ion beam bombardment of real cells to check whether and how very low-energy and low-fluence of ions can induce mutation. Argon and nitrogen ions at 5 keV and 2.5 keV respectively bombarded naked plasmid DNA pGFP to very low-fluences, an order of 10 13 ions/cm 2 . Subsequently, DNA states were analyzed using electrophoresis. Results provided evidences that the very low-energy and low-fluence ion bombardment indeed altered the DNA structure from supercoil to short linear fragments through multiple double strand breaks and thus induced mutation, which was confirmed by transfer of the bombarded DNA into bacteria Escherichia coli and subsequent expression of the marker gene.

  7. Influence of the ion bombardment of O{sub 2} plasmas on low-k materials

    Energy Technology Data Exchange (ETDEWEB)

    Verdonck, Patrick, E-mail: verdonck@imec.be [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Samara, Vladimir [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Open University, Materials Engineering, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Goodyear, Alec [Open University, Materials Engineering, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Ferchichi, Abdelkarim; Van Besien, Els; Baklanov, Mikhail R. [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Braithwaite, Nicholas [Open University, Department of Physics and Astronomy, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2011-10-31

    In this study, special tests were devised in order to investigate the influence of ion bombardment on the damage induced in low-k dielectrics by oxygen plasmas. By placing a sample that suffered a lot of ion bombardment and one which suffered little ion bombardment simultaneously in the same plasma, it was possible to verify that ion bombardment in fact helped to protect the low-k film against oxygen plasma induced damage. Exhaustive analyses (ellipsometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, porosimetry, capacitance-voltage (C-V) measurements, water contact angle analysis) show that ion bombardment induced the formation of a denser top layer in the film, which then hampered further penetration of active oxygen species deeper into the bulk. This was further confirmed by other tests combining capacitively and inductively coupled plasmas. Therefore, it was possible to conclude that, at least for these plasmas, ion bombardment may help to reduce plasma induced damage to low-k materials.

  8. Back bombardment for dispenser and lanthanum hexaboride cathodes

    Directory of Open Access Journals (Sweden)

    Mahmoud Bakr

    2011-06-01

    Full Text Available The back bombardment (BB effect limits wide usage of thermionic rf guns. The BB effect induces not only ramping-up of a cathode’s temperature and beam current, but also degradation of cavity voltage and beam energy during a macropulse. This paper presents a comparison of the BB effect for the case of dispenser tungsten-base (DC and lanthanum hexaboride (LaB_{6} thermionic rf gun cathodes. For each, particle simulation codes are used to simulate the BB effect and electron beam dynamics in a thermionic rf gun cathode. A semiempirical equation is also used to investigate the stopping range and deposited heat power of BB electrons in the cathode material. A numerical simulation method is used to calculate the change of the cathode temperature and current density during a single macropulse. This is done by solving two differential equations for the rf gun cavity equivalent circuit and one-dimensional thermal diffusion equation. High electron emission and small beam size are required for generation of a high-brightness electron beam, and so in this work the emission properties of the cathode are taken into account. Simulations of the BB effect show that, for a pulse of 6  μs duration, the DC cathode experiences a large change in the temperature compared with LaB_{6}, and a change in current density 6 times higher. Validation of the simulation results is performed using experimental data for beam current beyond the gun exit. The experimental data is well reproduced using the simulation method.

  9. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Zbigniew; Przybytniak, Grażyna; Nowicki, Andrzej

    2012-01-01

    The computer simulations based on Monte Carlo (MC) method and the ModeCEB software were carried out in connection with electron beam (EB) radiation set-up for crosslinking of electric wire and cable insulation. The theoretical predictions for absorbed dose distribution in irradiated electric insulation induced by scanned EB were compared to the experimental results of irradiation that was carried out in the experimental set-up based on ILU 6 electron accelerator with electron energy 0.5–2.0 MeV. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for various process parameters, namely electric wire and cable geometry (thickness of insulation layers and copper wire diameter), type of polymer insulation, electron energy, energy spread and geometry of electron beam, electric wire and cable layout in irradiation zone. The geometry of electron beam distribution in the irradiation zone was measured using CTA and PVC foil dosimeters for available electron energy range. The temperature rise of the irradiated electric wire and irradiation homogeneity were evaluated for different experimental conditions to optimize technological process parameters. The results of computer simulation are consistent with the experimental data of dose distribution evaluated by gel-fraction measurements. Such conformity indicates that ModeCEB computer simulation is reliable and sufficient for optimization absorbed dose distribution in the multi-layer circular objects irradiated with scanned electron beams. - Highlights: ► We model wire and cables irradiation process by Monte Carlo simulations. ► We optimize irradiation configuration for various process parameters. ► Temperature rise and irradiation homogeneity were evaluated. ► Calculation (dose) and experimental (gel-fraction) results were compared. ► Computer simulation was found reliable and sufficient for process optimization.

  10. Magnetically insulated H- diodes

    International Nuclear Information System (INIS)

    Fisher, A.; Bystritskii, V.; Garate, E.; Prohaska, R.; Rostoker, N.

    1993-01-01

    At the Univ. of California, Irvine, the authors have been studying the production of intense H - beams using pulse power techniques for the past 7 years. Previously, current densities of H - ions for various diode designs at UCI have been a few A/cm 2 . Recently, they have developed diodes similar to the coaxial design of the Lebedev Physical Institute, Moscow, USSR, where current densities of up to 200 A/cm 2 were reported using nuclear activation of a carbon target. In experiments at UCI employing the coaxial diode, current densities of up to 35 A/cm 2 from a passive polyethylene cathode loaded with TiH 2 have been measured using a pinhole camera and CR-39 track recording plastic. The authors have also been working on a self-insulating, annular diode which can generate a directed beam of H - ions. In the annular diode experiments a plasma opening switch was used to provide a prepulse and a current path which self-insulated the diode. These experiments were done on the machine APEX, a 1 MV, 50 ns, 7 Ω pulseline with a unipolar negative prepulse of ∼ 100 kV and 400 ns duration. Currently, the authors are modifying the pulseline to include an external LC circuit which can generate a bipolar, 150 kV, 1 μs duration prepulse (similar prepulse characteristic as in the Lebedev Institute experiments cited above)

  11. Plasma etching to enhance the surface insulating stability of alumina for fusion applications

    Directory of Open Access Journals (Sweden)

    M. Malo

    2016-12-01

    Full Text Available A significant increase in the surface electrical conductivity of alumina, considered one of the most promising insulating materials for numerous applications in fusion devices, has been observed during ion bombardment in vacuum due to oxygen loss by preferential sputtering. Although this is expected to cause serious limitations to insulating components functionality, recent studies showed it is possible to restore the damaged lattice by oxygen reincorporation during thermal treatments in air. These studies also revealed a correlation between conductivity and ion beam induced luminescence, which is being used to monitor surface electrical conductivity degradation and help qualify the post irradiation recovery. Work now carried out for Wesgo alumina considers oxygen implantation and plasma etching as additional methods to improve recovered layer depth and quality. Both conductivity and luminescence results indicate the potential use of plasma etching not only for damage recovery, but also as a pre-treatment to enhance material stability during irradiation.

  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. Effects of stern-foil submerged elevation on the lift and drag of a hydrofoil craft

    Science.gov (United States)

    Suastika, K.; Apriansyah

    2018-03-01

    Effects of the stern-foil submerged elevation on the lift and drag of a hydrofoil craft are studied by using computational fluid dynamics (CFD) and by considering three alternative stern-foil submerged elevations. The submerged elevation of the front foil is kept constant in all the alternatives. From among the alternatives, the deepest stern-foil placement results in the highest stern-foil lift with the highest foil’s lift-to-drag ratio. However, considering the lift-to-drag ratio of the whole foil-strut-hull system, the shallowest stern-foil placement results in the highest lift-to-drag ratio. The struts and the foil’s submerged elevation significantly affects the drag of the whole foil-strut-hull system.

  14. 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)

  15. Method for determining thickness and composition of foils

    International Nuclear Information System (INIS)

    Roessiger, V.

    1984-01-01

    Subject of the invention is a radiometric method for simultaneous determination of the thickness or mass per unit area and the chemical composition of foils consisting of two or more components. The method is based on the measurement of the attenuation of several components of a suitable polychromatic radiation

  16. Validation of calculated self-shielding factors for Rh foils

    Science.gov (United States)

    Jaćimović, R.; Trkov, A.; Žerovnik, G.; Snoj, L.; Schillebeeckx, P.

    2010-10-01

    Rhodium foils of about 5 mm diameter were obtained from IRMM. One foil had thickness of 0.006 mm and three were 0.112 mm thick. They were irradiated in the pneumatic transfer system and in the carousel facility of the TRIGA reactor at the Jožef Stefan Institute. The foils were irradiated bare and enclosed in small cadmium boxes (about 2 g weight) of 1 mm thickness to minimise the perturbation of the local neutron flux. They were co-irradiated with 5 mm diameter and 0.2 mm thick Al-Au (0.1%) alloy monitor foils. The resonance self-shielding corrections for the 0.006 and 0.112 mm thick samples were calculated by the Monte Carlo simulation and amount to about 10% and 60%, respectively. The consistency of measurements confirmed the validity of self-shielding factors. Trial estimates of Q0 and k0 factors for the 555.8 keV gamma line of 104Rh were made and amount to 6.65±0.18 and (6.61±0.12)×10 -2, respectively.

  17. Dynamic environmental control mechanisms for pneumatic foil constructions

    Science.gov (United States)

    Flor, Jan-Frederik; Wu, Yupeng; Beccarelli, Paolo; Chilton, John

    2017-11-01

    Membrane and foil structures have become over the last decades an attractive alternative to conventional materials and building systems with increasing implementation in different typologies and scale. The development of transparent, light, flexible and resistant materials like Ethylene Tetrafluoroethylene (ETFE) has triggered a rethinking of the building envelope in the building industry towards lightweight systems. ETFE foil cushions have proven to fulfil the design requirements in terms of structural efficiency and aesthetic values. But the strategies to satisfy increasing demands of energy efficiency and comfort conditions are still under development. The prediction and manipulation of the thermo-optical behaviour of ETFE foil cushion structures currently remain as one of the main challenges for designers and manufacturers. This paper reviews ongoing research regarding the control of the thermo-optical performance of ETFE cushion structures and highlights challenges and possible improvements. An overview of different dynamic and responsive environmental control mechanisms for multilayer foil constructions is provided and the state of the art in building application outlined by the discussion of case studies.

  18. PHYTOTOXICOLOGICAL TESTS - APPLICATIONS OF FOILS BASED ON GRAPHENE (GRAPHENE OXIDE

    Directory of Open Access Journals (Sweden)

    Petra ROUPCOVÁ

    2016-12-01

    Full Text Available This paper discusses the problematics of phytotoxicity of chemicals. It mainly focuses on the phytotoxicity of nanomaterials made of graphene. It describes phytotoxicological tests performed with foils from materials belonging to the graphene family. It also describes testing the influence of plants on these films. Furthermore, the paper discusses the issues of mutual influence between plants and tested nanomaterials.

  19. Tribalism as a Foiled Factor of Africa Nation-Building

    Science.gov (United States)

    Okogu, J. O.; Umudjere, S. O.

    2016-01-01

    This paper tends to examine tribalism as a foiled factor on Africa nation-building and proffers useful tips to salvaging the Africa land from this deadly social problem. Africans in times past had suffered enormous attacks, injuries, losses, deaths, destruction of properties and human skills and ideas due to the presence of tribalistic views in…

  20. Dose reader of dosimetric foil; Czytnik dawki folii dozymetrycznej

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B.; Strzalkowski, J.; Smolko, K.

    1997-12-31

    Read out the absorbance of a dosimetric foil is accomplished by two beam spectrophotometer. Such a solution makes possible the compensation of light source instabilities and ensures higher stability of the dose reader. The error of absorbance measurement caused by the instabilities does not exceed 0.0004 A. (author). 3 refs, 3 figs.

  1. Preparation of isotopic molybdenum foils utilizing small quantities of material

    Science.gov (United States)

    Lipski, A. R.; Lee, L. L.; Liang, J. F.; Mahon, J. C.

    1993-09-01

    A simple method utilizing a small amount of isotopic material for production of molybdenum foils is discussed. An e-gun is used in the procedure. The Mo powder undergoes reduction-sintering and melting-solidifying steps leading to the creation of a metallic droplet suitable for further cold rolling or vacuum deposition.

  2. 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.

  3. Modified Monkman–Grant relationship for austenitic stainless steel foils

    Energy Technology Data Exchange (ETDEWEB)

    Osman Ali, Hassan, E-mail: hassaninsan@gmail.com [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Tamin, Mohd Nasir, E-mail: taminmn@fkm.utm.my [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2013-02-15

    Characteristics of creep deformation for austenitic stainless steel foils are examined using the modified Monkman–Grant equation. A series of creep tests are conducted on AISI 347 steel foils at 700 °C and different stress levels ranging from 54 to 221 MPa. Results showed that at lower stress levels below 110 MPa, the creep life parameters ε{sub min},ε{sub r},t{sub r} can be expressed using the modified Monkman–Grant equation with exponent m′= 0.513. This indicates significant deviation of the creep behavior from the first order reaction kinetics theory for creep (m′ = 1.0). The true tertiary creep damage in AISI 347 steel foil begins after 65.9% of the creep life of the foil has elapsed at stress levels above 150 MPa. At this high stress levels, Monkman–Grant ductility factor λ{sup ′} saturates to a value of 1.3 with dislocation-controlled deformation mechanisms operating. At low stress levels, λ{sup ′} increases drastically (λ{sup ′}=190 at 54 MPa) when slow diffusion-controlled creep is dominant.

  4. 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...

  5. Foil bearing performance in liquid nitrogen and liquid oxygen

    Science.gov (United States)

    Genge, Gary G.; Saville, Marshall; Gu, Alston

    1993-01-01

    Space transfer vehicles and other power and propulsion systems require long-life turbopumps. Rolling-element bearings used in current turbopumps do not have sufficient life for these applications. Process fluid foil bearings have established long life, with exceptional reliability, over a wide range of temperatures and fluids in many high-speed turbomachinery applications. However, actual data on bearing performance in cryogenic fluids has been minimal. The National Aeronautics and Space Administration (NASA) and AlliedSignal Aerospace Systems and Equipment (ASE) have attempted to characterize the leaf-type compliant foil bearing in oxygen and nitrogen. The work performed under a joint internal research and development program between Marshall Space Flight Center (MSFC) and ASE demonstrated that the foil bearing has load capacities of at least 266 psi in liquid oxygen and 352 psi in liquid nitrogen. In addition, the bearing demonstrated a direct damping coefficient of 40 to 50 lb-sec/in. with a damping ratio of .7 to 1.4 in. liquid nitrogen using a bearing sized for upper-stage turbopumps. With the results from this testing and the years of successful use in air cycle machines and other applications, leaf-type compliant foil bearings are ready for testing in liquid oxygen turbopumps.

  6. The Visualization of Infrared Radiation Using Thermal Sensitive Foils

    Science.gov (United States)

    Bochnícek, Zdenek

    2013-01-01

    This paper describes a set of demonstration school experiments where infrared radiation is detected using thermal sensitive foils. The possibility of using standard glass lenses for infrared imaging is discussed in detail. It is shown that with optic components made from glass, infrared radiation up to 2.5 µm of wavelength can be detected. The…

  7. Comparison of Se and Te clusters produced by ion bombardment

    Directory of Open Access Journals (Sweden)

    Trzyna Małgorzata

    2017-01-01

    Full Text Available Nanostructures based on tellurium and selenium are materials used as components for the manufacturing topological insulators. Therefore it is crucial to precisely characterize these materials. In this work the emission of selenium and tellurium cluster ions, sputtered by Bi+ primary ion guns, was investigated by using Time-of-Flight Secondary Ion Mass Spectrometry (TOF SIMS. It has been found that BixTex and BixSex clusters appear in addition to Sex and Tex clusters in the mass range up to ~ 1300 m/z. Local maxima or minima (magic numbers are observed in the ion intensity versus a number of atoms per cluster for both positive and negative ions spectra for all types of clusters and primary ions used. These extrema can be attributed to different yield and stability of certain clusters but also to fragmentation of high-mass clusters.

  8. Comparison of Se and Te clusters produced by ion bombardment

    Science.gov (United States)

    Trzyna, Małgorzata

    2017-01-01

    Nanostructures based on tellurium and selenium are materials used as components for the manufacturing topological insulators. Therefore it is crucial to precisely characterize these materials. In this work the emission of selenium and tellurium cluster ions, sputtered by Bi+ primary ion guns, was investigated by using Time-of-Flight Secondary Ion Mass Spectrometry (TOF SIMS). It has been found that BixTex and BixSex clusters appear in addition to Sex and Tex clusters in the mass range up to 1300 m/z. Local maxima or minima (magic numbers) are observed in the ion intensity versus a number of atoms per cluster for both positive and negative ions spectra for all types of clusters and primary ions used. These extrema can be attributed to different yield and stability of certain clusters but also to fragmentation of high-mass clusters.

  9. Insulation structure of thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Takayuki; Usami, Saburo; Tsukamoto, Hideo; Kikuchi, Mitsuru

    1998-01-01

    The present invention provides an insulating structure of a thermonuclear device, in which insulation materials between toroidal coils are not broken even if superconductive toroidal coils are used. Namely, a tokamak type thermonuclear device of an insulating structure type comprises superconductive toroidal coils for confining plasmas arranged in a circular shape directing the center each at a predetermined angle, and the toroidal coils are insulated from each other. The insulation materials are formed by using a biaxially oriented fiber reinforced plastics. The contact surface of the toroidal coils and the insulating materials are arranged so that they are contact at a woven surface of the fiber reinforced plastics. Either or both of the contact surfaces of the fiber reinforced plastics and the toroidal coils are coated with a high molecular compound having a low friction coefficient. With such a constitution, since the interlayer shearing strength of the biaxially oriented fiber reinforced plastics is about 1/10 of the compression strength, the shearing stress exerted on the insulation material is reduced. Since a static friction coefficient on the contact surface is reduced to provide a structure causing slipping, shearing stress does not exceeds a predetermined limit. As a result, breakage of the insulation materials between the toroidal coils can be prevented. (I.S.)

  10. Plastic Materials for Insulating Applications.

    Science.gov (United States)

    Wang, S. F.; Grossman, S. J.

    1987-01-01

    Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

  11. Direct growth of hexagonal boron nitride/graphene heterostructures on cobalt foil substrates by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhongguang; Khanaki, Alireza; Tian, Hao; Zheng, Renjing; Suja, Mohammad; Liu, Jianlin, E-mail: jianlin@ece.ucr.edu [Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521 (United States); Zheng, Jian-Guo [Irvine Materials Research Institute, University of California, Irvine, California 92697-2800 (United States)

    2016-07-25

    Graphene/hexagonal boron nitride (G/h-BN) heterostructures have attracted a great deal of attention because of their exceptional properties and wide variety of potential applications in nanoelectronics. However, direct growth of large-area, high-quality, and stacked structures in a controllable and scalable way remains challenging. In this work, we demonstrate the synthesis of h-BN/graphene (h-BN/G) heterostructures on cobalt (Co) foil by sequential deposition of graphene and h-BN layers using plasma-assisted molecular beam epitaxy. It is found that the coverage of h-BN layers can be readily controlled on the epitaxial graphene by growth time. Large-area, uniform-quality, and multi-layer h-BN films on thin graphite layers were achieved. Based on an h-BN (5–6 nm)/G (26–27 nm) heterostructure, capacitor devices with Co(foil)/G/h-BN/Co(contact) configuration were fabricated to evaluate the dielectric properties of h-BN. The measured breakdown electric field showed a high value of ∼2.5–3.2 MV/cm. Both I-V and C-V characteristics indicate that the epitaxial h-BN film has good insulating characteristics.

  12. Magnetically self-insulated transformers

    International Nuclear Information System (INIS)

    Novac, B.M.; Smith, I.R.; Brown, J.

    2002-01-01

    Magnetic insulation is the only practicable form of insulation for much equipment used in ultrahigh pulsed-power work, including transmission lines and plasma opening switches. It has not however so far been successfully exploited in the transformers that are necessarily involved, and the first proposed design that appeared more than 30 years ago raised apparently insuperable problems. The two novel arrangements for a magnetically insulated transformer described in this paper overcome the problems faced by the earlier designs and also offer considerable scope for development in a number of important areas. Theoretical justification is given for their insulating properties, and this is confirmed by proof-of-principle results obtained from a small-scale experimental prototype in which magnetic insulation was demonstrated at up to 100 kV. (author)

  13. 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)

  14. Research on vacuum insulation for cryocables

    International Nuclear Information System (INIS)

    Graneau, P.

    1974-01-01

    Vacuum insulation, as compared with solid insulation, simplifies the construction of both resistive or superconducting cryogenic cables. The common vacuum space in the cable can furnish thermal insulation between the environment and the cryogenic coolant, provide electrical insulation between conductors, and establish thermal isolation between go- and return-coolant streams. The differences between solid and vacuum high voltage insulation are discussed, and research on the design, materials selection, and testing of vacuum insulated cryogenic cables is described

  15. 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.

  16. Experimental and theoretical analysis of a rigid rotor supported by air foil bearings

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Hansen, Asger J. T.; Santos, Ilmar

    2015-01-01

    The popularity of compressors utilizing foil bearings is increasing. Their mechanical design is challenging, and an accurate prediction of the bearing coefficients is important. A mathematical model taking into account the foil structure, and the detailed geometry of a three pad foil bearing...

  17. Wobbling The Galactic Disk with Bombardment of Satellite Galaxies

    Science.gov (United States)

    D'Onghia, Elena

    We propose to assess the effect of impacts of large visible satellite galaxies on a disk, as well as the relevance of the continuing bombardment of the Galactic disk by dark matter clumps as predicted by the current cosmological framework that can wobble the disk, heating it and eventually exciting ragged spiral structures. In particular, we make detailed predictions for observable features such as spiral arms, rings and their associated stars in galactic disks and relate them to the physical processes that drive their formation and evolution in our Milky Way galaxy and nearby spirals. To do this, we will combine analytic methods and numerical simulations that allow us to calculate observables, which we will compare to present and forthcoming observations. Our methodology utilizes a combination of state of the art hydrodynamic simulations of galaxy evolution and multi- wavelength radiative transfer simulations. Our primary goals are: (1) To identify the physical processes that are responsible for spiral structure formation observed in our Milky Way and nearby disk galaxies, from the flocculent to grand- designed spiral galaxies and to provide observable signatures to be compared with data on nearby galaxies combining maps of 24 micron emission (Spitzer) and cold gas, CO (Heracles) and HI (THINGS). (2) To explore different morphologies of spiral galaxies: from the multi-armed galaxies to the Milky Way sized galaxies with few arms. (3) For a Milky Way disk we will assess the effect of impacts of substructures passing through the disk to origin the asymmetry in the number density of stars recently discovered from SDSS and SEGUE data and confirmed from RAVE data. We will also investigate the disk heating in the vertical plane due to the formation of vertical oscillations that are produced by the impact and migration of stars in the disk as consequence of the heating as compared to the classical stellar migration mechanism. (4) We will measure the spiral pattern speed

  18. Excitons in insulators

    International Nuclear Information System (INIS)

    Grasser, R.; Scharmann, A.

    1983-01-01

    This chapter investigates absorption, reflectivity, and intrinsic luminescence spectra of free and/or self-trapped (localized) excitons in alkali halides and rare gas solids. Introduces the concepts underlying the Wannier-Mott and Frenkel exciton models, two extreme pictures of an exciton in crystalline materials. Discusses the theoretical and experimental background; excitons in alkali halides; and excitons in rare gas solids. Shows that the intrinsic optical behavior of wide gap insulators in the range of the fundamental absorption edge is controlled by modified Wannier-Mott excitons. Finds that while that alkali halides only show free and relaxed molecular-like exciton emission, in rare gas crystals luminescence due to free, single and double centered localized excitons is observed. Indicates that the simultaneous existence of free and self-trapped excitons in these solid requires an energy barrier for self-trapping

  19. Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

    Science.gov (United States)

    Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

    2012-07-01

    The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm2) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

  20. Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

    International Nuclear Information System (INIS)

    Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

    2012-01-01

    The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm 2 ) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

  1. Microchannel neural interface manufacture by stacking silicone and metal foil laminae

    Science.gov (United States)

    Lancashire, Henry T.; Vanhoestenberghe, Anne; Pendegrass, Catherine J.; Ajam, Yazan Al; Magee, Elliot; Donaldson, Nick; Blunn, Gordon W.

    2016-06-01

    Objective. Microchannel neural interfaces (MNIs) overcome problems with recording from peripheral nerves by amplifying signals independent of node of Ranvier position. Selective recording and stimulation using an MNI requires good insulation between microchannels and a high electrode density. We propose that stacking microchannel laminae will improve selectivity over single layer MNI designs due to the increase in electrode number and an improvement in microchannel sealing. Approach. This paper describes a manufacturing method for creating MNIs which overcomes limitations on electrode connectivity and microchannel sealing. Laser cut silicone—metal foil laminae were stacked using plasma bonding to create an array of microchannels containing tripolar electrodes. Electrodes were DC etched and electrode impedance and cyclic voltammetry were tested. Main results. MNIs with 100 μm and 200 μm diameter microchannels were manufactured. High electrode density MNIs are achievable with electrodes present in every microchannel. Electrode impedances of 27.2 ± 19.8 kΩ at 1 kHz were achieved. Following two months of implantation in Lewis rat sciatic nerve, micro-fascicles were observed regenerating through the MNI microchannels. Significance. Selective MNIs with the peripheral nervous system may allow upper limb amputees to control prostheses intuitively.

  2. Effects of hyperthermal proton bombardment on alkanethiol self-assembled monolayer on Au(1 1 1)

    Energy Technology Data Exchange (ETDEWEB)

    Xi Luan [Surface Science Western, University of Western Ontario, London, Ontario N6A 5B7 (Canada); Zheng Zhi; Lam, N.-S. [Department of Physics, Chinese University of Hong Kong, Shatin, Hong Kong (China); Grizzi, Oscar [Centro Atomico Bariloche, 8400 San Carlos de Bariloche, Rio Negro (Argentina); Lau, W.-M. [Surface Science Western, University of Western Ontario, London, Ontario N6A 5B7 (Canada)], E-mail: llau22@uwo.ca

    2007-10-31

    The effects of hyperthermal proton bombardment on alkanethiol self-assembled monolayer (SAM) on Au(1 1 1) are studied with scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS). The STM and XPS results show that proton bombardment with proton energy as low as 2 eV can induce cross-linking of the adsorbed alkanethiols and transform the original ordered SAM lattice to an array of nanoclusters of the cross-linked alkanethiols. For a bombardment at 3 eV with a fluence of 3x10{sup 15} cm{sup -2}, the typical cluster size is about 5 nm. In addition, the cluster size distribution is narrow, with no cluster larger than 8 nm. The cluster growth can be promoted by increasing the fluence at a fixed bombardment energy or increasing the energy at a fixed fluence. This indicates that surface diffusion of alkanethiols and cluster growth can be harnessed by the control of the bombardment energy and fluence.

  3. Effects of hyperthermal proton bombardment on alkanethiol self-assembled monolayer on Au(1 1 1)

    International Nuclear Information System (INIS)

    Xi Luan; Zheng Zhi; Lam, N.-S.; Grizzi, Oscar; Lau, W.-M.

    2007-01-01

    The effects of hyperthermal proton bombardment on alkanethiol self-assembled monolayer (SAM) on Au(1 1 1) are studied with scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS). The STM and XPS results show that proton bombardment with proton energy as low as 2 eV can induce cross-linking of the adsorbed alkanethiols and transform the original ordered SAM lattice to an array of nanoclusters of the cross-linked alkanethiols. For a bombardment at 3 eV with a fluence of 3x10 15 cm -2 , the typical cluster size is about 5 nm. In addition, the cluster size distribution is narrow, with no cluster larger than 8 nm. The cluster growth can be promoted by increasing the fluence at a fixed bombardment energy or increasing the energy at a fixed fluence. This indicates that surface diffusion of alkanethiols and cluster growth can be harnessed by the control of the bombardment energy and fluence

  4. 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.).

  5. 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.)

  6. Hydrogen pumping and release by graphite under high flux plasma bombardment

    International Nuclear Information System (INIS)

    Hirooka, Y.; Leung, W.K.; Conn, R.W.; Goebel, D.M.; Labombard, B.; Nygren, R.; Wilson, K.L.

    1988-01-01

    Inert gas (helium or argon) plasma bombardment has been found to increase the surface gas adsorptivity of isotropic graphite (POCO-graphite), which can then getter residual gases in a high vacuum system. The inert gas plasma bombardment was carried out at a flux ∼ 1 x 10 18 ions s -1 cm -2 to a fluence of the order of 10 21 ions/cm 2 and at temperatures around 800 degree C. The plasma bombarding energy was varied between 100 and 200 eV. The gettering speed of the activated graphite surface is estimated to be as large as 25 liters s -1 cm -2 at total pressures between 10 -6 and 10 -7 torr. The gettering capacity estimated is 0.025 torr-liter/cm 2 at room temperature. The gettering capability of graphite can be easily recovered by repeating inert gas plasma bombardment. The activated graphite surface exhibits a smooth, sponge-like morphology with significantly increased pore openings, which correlates with the observed increase in the surface gas adsorptivity. The activated graphite surface has been observed to pump hydrogen plasma particles as well. From calibrated H-alpha measurements, the dynamic hydrogen retention capacity is evaluated to be as large as 2 x 10 18 H/cm 2 at temperatures below 100 degree C and at a plasma bombarding energy of 300 eV

  7. Evolution of atomic-scale surface structures during ion bombardment: A fractal simulation

    International Nuclear Information System (INIS)

    Shaheen, M.A.; Ruzic, D.N.

    1993-01-01

    Surfaces of interest in microelectronics have been shown to exhibit fractal topographies on the atomic scale. A model utilizing self-similar fractals to simulate surface roughness has been added to the ion bombardment code TRIM. The model has successfully predicted experimental sputtering yields of low energy (less then 1000 eV) Ar on Si and D on C using experimentally determined fractal dimensions. Under ion bombardment the fractal surface structures evolve as the atoms in the collision cascade are displaced or sputtered. These atoms have been tracked and the evolution of the surface in steps of one monolayer of flux has been determined. The Ar--Si system has been studied for incidence energies of 100 and 500 eV, and incidence angles of 0 degree, 30 degree, and 60 degree. As expected, normally incident ion bombardment tends to reduce the roughness of the surface, whereas large angle ion bombardment increases the degree of surface roughness. Of particular interest though, the surfaces are still locally self-similar fractals after ion bombardment and a steady state fractal dimension is reached, except at large angles of incidence

  8. Mechanisms of ion-bombardment-induced DNA transfer into bacterial E. coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.D., E-mail: yuld@thep-center.org [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Phanchaisri, B. [Institute of Science and Technology Research, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Singkarat, S. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-05-01

    Highlights: • Ion bombardment could induce DNA transfer into E. coli cells. • The DNA transfer induction depended on ion energy and fluence. • The mechanism was associated with the bacterial cell envelope structure. • A mechanism phase diagram was proposed to summarize the mechanism. - Abstract: As a useful ion beam biotechnology, ion-bombardment-induced DNA transfer into bacterial Escherichia coli (E. coli) cells has been successfully operated using argon ions. In the process ion bombardment of the bacterial cells modifies the cell envelope materials to favor the exogenous DNA molecules to pass through the envelope to enter the cell. The occurrence of the DNA transfer induction was found ion energy and fluence dependent in a complex manner. At ion energy of a few keV and a few tens of keV to moderate fluences the DNA transfer could be induced by ion bombardment of the bacterial cells, while at the same ion energy but to high fluences DNA transfer could not be induced. On the other hand, when the ion energy was medium, about 10–20 keV, the DNA transfer could not be induced by ion bombardment of the cells. The complexity of the experimental results indicated a complex mechanism which should be related to the complex structure of the bacterial E. coli cell envelope. A phase diagram was proposed to interpret different mechanisms involved as functions of the ion energy and fluence.

  9. Mechanisms of ion-bombardment-induced DNA transfer into bacterial E. coli cells

    International Nuclear Information System (INIS)

    Yu, L.D.; Sangwijit, K.; Prakrajang, K.; Phanchaisri, B.; Thongkumkoon, P.; Thopan, P.; Singkarat, S.; Anuntalabhochai, S.

    2014-01-01

    Highlights: • Ion bombardment could induce DNA transfer into E. coli cells. • The DNA transfer induction depended on ion energy and fluence. • The mechanism was associated with the bacterial cell envelope structure. • A mechanism phase diagram was proposed to summarize the mechanism. - Abstract: As a useful ion beam biotechnology, ion-bombardment-induced DNA transfer into bacterial Escherichia coli (E. coli) cells has been successfully operated using argon ions. In the process ion bombardment of the bacterial cells modifies the cell envelope materials to favor the exogenous DNA molecules to pass through the envelope to enter the cell. The occurrence of the DNA transfer induction was found ion energy and fluence dependent in a complex manner. At ion energy of a few keV and a few tens of keV to moderate fluences the DNA transfer could be induced by ion bombardment of the bacterial cells, while at the same ion energy but to high fluences DNA transfer could not be induced. On the other hand, when the ion energy was medium, about 10–20 keV, the DNA transfer could not be induced by ion bombardment of the cells. The complexity of the experimental results indicated a complex mechanism which should be related to the complex structure of the bacterial E. coli cell envelope. A phase diagram was proposed to interpret different mechanisms involved as functions of the ion energy and fluence

  10. MD and BCA simulations of He and H bombardment of fuzz in bcc elements

    Science.gov (United States)

    Klaver, T. P. C.; Zhang, S.; Nordlund, K.

    2017-08-01

    We present results of MD simulations of low energy He ion bombardment of low density fuzz in bcc elements. He ions can penetrate several micrometers into sparse fuzz, which allows for a sufficient He flux through it to grow the fuzz further. He kinetic energy falls off exponentially with penetration depth. A BCA code was used to carry out the same ion bombardment on the same fuzz structures as in MD simulations, but with simpler, 10 million times faster calculations. Despite the poor theoretical basis of the BCA at low ion energies, and the use of somewhat different potentials in MD and BCA calculations, the ion penetration depths predicted by BCA are only ∼12% less than those predicted by MD. The MD-BCA differences are highly systematic and trends in the results of the two methods are very similar. We have carried out more than 200 BCA calculation runs of ion bombardment of fuzz, in which parameters in the ion bombardment process were varied. For most parameters, the results show that the ion bombardment process is quite generic. The ion species (He or H), ion mass, fuzz element (W, Ta, Mo, Fe) and fuzz element lattice parameter turned out to have a modest influence on ion penetration depths at most. An off-normal angle of incidence strongly reduces the ion penetration depth. Increasing the ion energy increases the ion penetration, but the rate by which ion energy drops off at high ion energies follows the same exponential pattern as at lower energies.

  11. ANALYTICAL MODELING OF ELECTRON BACK-BOMBARDMENT INDUCED CURRENT INCREASE IN UN-GATED THERMIONIC CATHODE RF GUNS

    Energy Technology Data Exchange (ETDEWEB)

    Edelen, J. P. [Fermilab; Sun, Y. [Argonne; Harris, J. R. [AFRL, NM; Lewellen, J. W. [Los Alamos Natl. Lab.

    2016-09-28

    In this paper we derive analytical expressions for the output current of an un-gated thermionic cathode RF gun in the presence of back-bombardment heating. We provide a brief overview of back-bombardment theory and discuss comparisons between the analytical back-bombardment predictions and simulation models. We then derive an expression for the output current as a function of the RF repetition rate and discuss relationships between back-bombardment, fieldenhancement, and output current. We discuss in detail the relevant approximations and then provide predictions about how the output current should vary as a function of repetition rate for some given system configurations.

  12. Dual scattering foil design for poly-energetic electron beams

    International Nuclear Information System (INIS)

    Kainz, K K; Antolak, J A; Almond, P R; Bloch, C D; Hogstrom, K R

    2005-01-01

    The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm 2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly

  13. Development, characterization and qualification of first GEM foils produced in India

    Science.gov (United States)

    Shah, Aashaq; Ahmed, Asar; Gola, Mohit; Sharma, Ram Krishna; Malhotra, Shivali; Kumar, Ashok; Naimuddin, Md.; Menon, Pradeep; Srinivasan, K.

    2018-06-01

    The increasing demand for Gas Electron Multiplier (GEM) foils has been driven by their application in many current and proposed high-energy physics experiments. Micropack, a Bengaluru-based company, has established and commercialized GEM foils for the first time in India. Micropack used the double-mask etching technique to successfully produce 10 cm × 10 cm GEM foil. In this paper, we report on the development as well as the geometrical and electrical properties of these foils, including the size uniformity of the holes and leakage current measurements. Our characterization studies show that the foils are of good quality and satisfy all the necessary quality control criteria.

  14. Measurements of laser generated soft X-ray emission from irradiated gold foils

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J. S.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D. [University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109 (United States); Frank, Y.; Raicher, E.; Fraenkel, M. [Soreq Nuclear Research Center, Yavne (Israel)

    2016-11-15

    Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  15. Lightweight, Thermally Insulating Structural Panels

    Science.gov (United States)

    Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

    1996-01-01

    Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

  16. Reflecting variable opening insulating panel

    International Nuclear Information System (INIS)

    Nungesser, W.T.

    1976-01-01

    A description is given of a reflecting variable opening insulating panel assembly, comprising a static panel assembly of reflecting insulation sheets forming a cavity along one side of the panel and a movable panel opening out by sliding from the cavity of the static panel, and a locking device for holding the movable panel in a position extending from the cavity of the static panel. This can apply to a nuclear reactor of which the base might require maintenance and periodical checking and for which it is desirable to have available certain processes for the partial dismantling of the insulation [fr

  17. 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.

  18. The surface topography of Inconel, stainless steel and copper after argon ion bombardment

    International Nuclear Information System (INIS)

    Vogelbruch, K.; Vietzke, E.

    1983-01-01

    Energetic particle bombardment of metals is known to change the surface topography. To simulate the behaviour of the first wall of a fusion device under real plasma conditions, we have investigated the surface topography of rotating targets after 30 keV argon ion bombardment at 70deg incident angle by electron scanning micrographs. Under these conditions Inconel 600, 601, 625, stainless steel, and copper showed no cones, pyramids or cliffs, but only etching figures and at higher ion doses relatively flat hills. Thus, it can be concluded, that the influence of energetic particles on the first wall of a fusion reactor is smaller than expected from the results of such sputtering experiments, which have dealt with the formation of surface structures under ion bombardment at constant incident direction. (author)

  19. Excited-atom production by electron and ion bombardment of alkali halides

    International Nuclear Information System (INIS)

    Walkup, R.E.; Avouris, P.; Ghosh, A.P.

    1987-01-01

    We present experimental results on the production of excited atoms by electron and ion bombardment of alkali halides. For the case of electron bombardment, Doppler shift measurements show that the electronically excited atoms have a thermal velocity distribution in equilibrium with the surface temperature. Measurements of the absolute yield of excited atoms, the distribution of population among the excited states, and the systematic dependence on incident electron current and sample temperature support a model in which the excited atoms are produced by gas-phase collisions between desorbed ground-state atoms and secondary electrons. In contrast, for the case of ion bombardment, the excited atoms are directly sputtered from the surface, with velocity distributions characteristic of a collision cascade, and with typical energies of --10 eV

  20. Alteration of the UV-visible reflectance spectra of H2O ice by ion bombardment

    Science.gov (United States)

    Sack, N. J.; Boring, J. W.; Johnson, R. E.; Baragiola, R. A.; Shi, M.

    1991-01-01

    Satellite in the Jovian and Saturnian system exhibit differences in reflectivity between their 'leading' and 'trailing' surfaces which can affect the local vapor pressure. Since these differences are thought to be due to differences in the flux of bombarding magnetospheric ions, the influence of ion impact on the UV-visible reflectance of water ice surfaces (20-90 K) by keV ion bombardment was studied. An observed decrease in reflectance in the UV is attributed to rearrangement processes that affect the physical microstructure and surface 'roughness'. The ratio in reflectance of bombarded to freshly deposited films is compared to the ratio of the reflectance of the leading and trailing hemispheres for Europa and Ganymede.

  1. InN: Fermi level stabilization by low-energy ion bombardment

    International Nuclear Information System (INIS)

    Piper, L.F.J.; Veal, T.D.; McConville, C.F.; Lu, H.; Schaff, W.J.

    2006-01-01

    The near-surface electronic properties of InN have been investigated with high-resolution electron-energy loss spectroscopy. Low-energy (∝400 eV) nitrogen ion bombardment followed by low temperature annealing (<300 C) was found to dramatically increase the n-type conductivity of InN, close to the surface. This is explained in terms of the formation of amphoteric defects from the ion bombardment and annealing combined with the band structure of InN. Low-energy ion bombardment and annealing is shown to result in a damage-induced, donor-like defect-profile instead of the expected electron accumulation for InN. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Nuclear reactor pressure vessel with an inner metal coating covered with a high temperature resistant thermal insulator

    International Nuclear Information System (INIS)

    1974-01-01

    The thermal insulator covering the metal coating of a reactor vessel is designed for resisting high temperatures. It comprises one or several porous layers of ceramic fibers or of stacked metal foils, covered with a layer of bricks or ceramic tiles. The latter are fixed in position by fasteners comprising pins fixed to the coating and passing through said porous layers and fasteners (nut or bolts) for individually fixing the bricks to said pins, whereas ceramic plugs mounted on said bricks or tiles provide for the thermal insulation of the pins and of the nuts or bolts; such a thermal insulation can be applied to high-temperature reactors or to fast reactors [fr

  3. Laser spot welding of cobalt-based amorphous metal foils

    International Nuclear Information System (INIS)

    Runchev, Dobre; Dorn, Lutc; Jaferi, Seifolah; Purbst, Detler

    1997-01-01

    The results concerning weldability of amorphous alloy (VAC 6025F) in shape of foils and the quality of laser-spot welded joints are presented in this paper. The aim of the research was the production of a high quality welding joint, by preserving the amorphous structure. The quality of the joint was tested by shear strength analysis and microhardness measuring. The metallographic studies were made by using optical microscope and SEM. The results show that (1) overlapped Co based amorphous metals foils can be welded with high-quality by a pulsed Nd: YAG-Laser, but only within a very narrow laser parameter window; (2) the laser welded spots show comparably high strength as the basic material; (3) the structure of the welded spot remains amorphous, so that the same characteristics as the base material can be achieved. (author)

  4. Wavelength shifting reflector foils for liquid Ar scintillation light

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Manuel [Physik Institut, Universitaet Zuerich (Switzerland); Collaboration: GERDA-Collaboration

    2013-07-01

    Liquid argon is used as a scintillator in several present and upcoming experiments. In Gerda it is used as a coolant, shielding and will be instrumented to become an active veto in Phase II. Its scintillation light has a wavelength of 128 nm, that gets absorbed by quartz. In order to measure the light using photo multiplier tubes (PMT) for cryogenic temperatures which have a quartz window, it is converted to longer wavelength by coated reflector foils. The conversion efficiency and stability of several such coatings was optimized using VM2000 and Tetratex separately as reflector foils. The efficiency has been measured in a liquid Ar set up build especially for this purpose. It employs a 3'' low radioactivity PMT of type R11065-10 from Hamamatsu, the favorite photo sensor candidate to be used in Gerda.

  5. Thrombogenicity tests on ar-irradiated polycarbonate foils

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H., E-mail: g.ferraz@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica; Delgado, Adriana O. [Universidade Federal de Sao Carlos (UFSCAR), Sorocaba, SP (Brazil); Cunha, Tatiana F. [Biosintesis P and D do Brasil, Sao Paulo, SP (Brazil); Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

    2013-07-01

    Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

  6. Ground effect on a self-propelled undulatory foil

    Science.gov (United States)

    Zhang, Dong; Chao, Liming; Pan, Guang

    2018-04-01

    The unsteady ground effect on a self-propelled undulatory foil is numerically investigated in this paper. The situation can be widely found in nature especially for fish swimming near the ground. In this study, frequency varies from 0.1 Hz to 2 Hz and distance from the ground varies from 0.2 L to 1 L. Under most kinematics, the ground has a negative effect on the performance of the foil. The swimming velocity slows down, power spend increases and swimming economy reduces. The higher frequency can produce a larger negative effect. Only at the low frequencies f = 0.1 Hz, 0.25 Hz and 0.5 Hz with distance of 0.2 L the velocity can be enhanced by 18%, 6%, 0.8%, respectively. The lift production is found to be increased. The link between the performance and the wake dynamics is also established by studying the vortex structures.

  7. 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

  8. 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)

  9. CHARACTERIZATION OF MONOLITHIC FUEL FOIL PROPERTIES AND BOND STRENGTH

    International Nuclear Information System (INIS)

    D E Burkes; D D Keiser; D M Wachs; J S Larson; M D Chapple

    2007-01-01

    Understanding fuel foil mechanical properties, and fuel/cladding bond quality and strength in monolithic plates is an important area of investigation and quantification. Specifically, what constitutes an acceptable monolithic fuel--cladding bond, how are the properties of the bond measured and determined, and what is the impact of fabrication process or change in parameters on the level of bonding? Currently, non-bond areas are quantified employing ultrasonic determinations that are challenging to interpret and understand in terms of irradiation impact. Thus, determining mechanical properties of the fuel foil and what constitutes fuel/cladding non-bonds is essential to successful qualification of monolithic fuel plates. Capabilities and tests related to determination of these properties have been implemented at the INL and are discussed, along with preliminary results

  10. 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

  11. Thrombogenicity tests on ar-irradiated polycarbonate foils

    International Nuclear Information System (INIS)

    Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H.; Cunha, Tatiana F.; Higa, Olga Z.

    2013-01-01

    Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

  12. A new method for alkaline dissolution of uranium metal foil

    International Nuclear Information System (INIS)

    Mondino, A.V.; Wilkinson, M.V.; Manzini, A.C.

    2001-01-01

    In order to develop a production process of 99 Mo by fission of low-enriched uranium, the first purification step, which consists of dissolution of a uranium metal foil target, was studied. It was found that alkaline NaClO gave good results, reaching the dissolution of up to 300 μm of uranium foil. The different conditions for the dissolution were studied and the optimum ones were found. The influence of NaClO and NaOH concentration, temperature, dissolving solution volume per unit of surface and dissolution time were investigated. During this step, a gas identified as H 2 , was generated, and a precipitate characterized as Na 2 U 2 O 7 was observed. A stoichiometric reaction for this uranium dissolution is proposed. (author)

  13. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuldyuld@gmail.com [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

  14. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    International Nuclear Information System (INIS)

    Thopan, P.; Prakrajang, K.; Thongkumkoon, P.; Suwannakachorn, D.; Yu, L.D.

    2013-01-01

    Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells

  15. Molecular dewetting on insulators

    International Nuclear Information System (INIS)

    Burke, S A; Topple, J M; Gruetter, P

    2009-01-01

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C 60 on alkali halides, and the technologically important system of pentacene on SiO 2 . These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure. (topical review)

  16. Molecular dewetting on insulators.

    Science.gov (United States)

    Burke, S A; Topple, J M; Grütter, P

    2009-10-21

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.

  17. Insulating fcc YH

    International Nuclear Information System (INIS)

    Molen, S. J. van der; Nagengast, D. G.; Gogh, A. T. M. van; Kalkman, J.; Kooij, E. S.; Rector, J. H.; Griessen, R.

    2001-01-01

    We study the structural, optical, and electrical properties of Mg z Y 1-z switchable mirrors upon hydrogenation. It is found that the alloys disproportionate into essentially pure YH 3-δ and MgH 2 with the crystal structure of YH 3-δ dependent on the Mg concentration z. For 0 3-δ are observed, whereas for z≥0.1 only cubic YH 3-δ is present. Interestingly, cubic YH 3-δ is expanded compared to YH 2 , in disagreement with theoretical predictions. From optical and electrical measurements we conclude that cubic YH 3-δ is a transparent insulator with properties similar to hexagonal YH 3-δ . Our results are inconsistent with calculations predicting fcc YH 3-δ to be metallic, but they are in good agreement with recent GW calculations on both hcp and fcc YH 3 . Finally, we find an increase in the effective band gap of the hydrided Mg z Y 1-z alloys with increasing z. Possibly this is due to quantum confinement effects in the small YH 3 clusters

  18. Oxidation-assisted graphene heteroepitaxy on copper foil

    OpenAIRE

    Reckinger, Nicolas; Tang, Xiaohui; Joucken, Frédéric; Lajaunie, Luc; Arenal, Raul; Dubois, Emmanuel; Hackens, Benoît; Henrard, Luc; Colomer, Jean-François

    2016-01-01

    We propose an innovative, easy-to-implement approach to synthesize large-area singlecrystalline graphene sheets by chemical vapor deposition on copper foil. This method doubly takes advantage of residual oxygen present in the gas phase. First, by slightly oxidizing the copper surface, we induce grain boundary pinning in copper and, in consequence, the freezing of the thermal recrystallization process. Subsequent reduction of copper under hydrogen suddenly unlocks the delayed reconstruction, f...

  19. Beam-foil level lifetimes in krypton III

    International Nuclear Information System (INIS)

    Coetzer, F.J.; Kotze, P.B.; Westhuizen, P. van der

    1982-01-01

    The radiative lifetimes of levels in doubly-ionized Krypton have been measured after foil excitation of a beam of Krypton particles in the wavelength range 120-500 nm. The results are compared with the experimental values obtained by Fink et al., as well as theoretical values resulting from Coulomb (C.A.) and single configuration Hartree-Fock (H.F.) calculations. (orig.)

  20. 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)

  1. Effect of phototherapy with alumunium foil reflectors on neonatal hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Tony Ijong Dachlan

    2015-03-01

    Full Text Available Background Neonatal hyperbilirubinemia (NH is one of the most common problems in neonates, but it can be treated with blue light phototherapy. Developing countries with limited medical equipment and funds have difficulty providing effective phototherapy to treat NH, leading to increased risk of bilirubin encephalopathy. Phototherapy with white reflecting curtains can decrease the duration of phototherapy needed to reduce bilirubin levels. Objective To compare the duration of phototherapy needed in neonates with NH who underwent phototherapy with and without aluminum foil reflectors. Methods This open clinical trial was conducted from July to August 2013 at Dr. Hasan Sadikin Hospital, Bandung, Indonesia. The inclusion criteria were term neonates with uncomplicated NH presenting in their first week of life. Subjects were randomized into two groups, those who received phototherapy with or without aluminum foil reflectors. Serum bilirubin is taken at 12th, 24th, 48th hours, then every 24 hours if needed until phototherapy can be stopped according to American Academy of Pediatrics guidelines. The outcome measured was the duration of phototherapy using survival analysis. The difference between the two groups was tested by Gehan method. Results Seventy newborns who fulfilled the inclusion criteria and had similar characteristics were randomized into two groups. The duration of phototherapy needed was significantly less in the group with aluminum foil reflectors than in the group without reflectors [72 vs. 96 hours, respectively, (P<0.01]. Conclusion The required duration of phototherapy with aluminum foil reflectors is significantly less than that of phototherapy without reflectors, in neonates with NH.

  2. Thermoelectric and Hall-effect studies in hydrogenerated nickel foils

    International Nuclear Information System (INIS)

    Rani, R.; Nigam, A.N.

    1978-01-01

    Thermo e.m.f. and Hall constant of hydrogenerated nickel foils have been measured. Termo e.m.f. shows a sign reversal which is not due to the change in sign of the charge carriers, as indicated by the Hall-effect measurements. To account for the sign reversal of thermo e.m.f., it is found necessary to take into account the surface states of chemisorbed hydrogen on nickel

  3. 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

  4. Topological Insulator Nanowires and Nanoribbons

    KAUST Repository

    Kong, Desheng; Randel, Jason C.; Peng, Hailin; Cha, Judy J.; Meister, Stefan; Lai, Keji; Chen, Yulin; Shen, Zhi-Xun; Manoharan, Hari C.; Cui, Yi

    2010-01-01

    Recent theoretical calculations and photoemission spectroscopy measurements on the bulk Bi2Se3 material show that it is a three-dimensional topological insulator possessing conductive surface states with nondegenerate spins, attractive

  5. Measure Guideline: Basement Insulation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Mantha, P.; Puttagunta, S.

    2012-10-01

    This guideline is intended to describe good practices for insulating basements in new and existing homes, and is intended to be a practical resources for building contractors, designers, and also to homeowners.

  6. Metal-insulator-semiconductor photodetectors.

    Science.gov (United States)

    Lin, Chu-Hsuan; Liu, Chee Wee

    2010-01-01

    The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  7. Metal-Insulator-Semiconductor Photodetectors

    Directory of Open Access Journals (Sweden)

    Chu-Hsuan Lin

    2010-09-01

    Full Text Available The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  8. 16 CFR 460.18 - Insulation ads.

    Science.gov (United States)

    2010-01-01

    ... Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness, the...

  9. Flapping propulsion with side-by-side pitching foils

    Science.gov (United States)

    Huera-Huarte, Francisco

    2016-11-01

    Fish schools are one of the most common types of collective behaviour observed in nature. One of the reasons why fish swim in groups, is to reduce the cost of transport of the school. In this work we explore the propulsive performance of two foils flapping in a symmetric configuration, i.e. with an out-of-phase flapping motion. Direct thrust measurements and Particle Image Velocimetry (PIV) allowed a detailed examination of the forces and the wake generated by the system, for different kinematics (swept angles and frequencies) and shaft separations. For certain specific cases, volumetric PIV shows major differences on how the different structures in the wake of the system evolve, depending on the imposed kinematics and the side-by-side separation between the foils. Results obtained will be compared against data produced with isolated flapping foils with similar imposed kinematics, with the aim to better understand the interactions between both and the performance of the system as a whole. The author would like to acknowledge the financial support provided by the Spanish Ministerio de Economia y competitividad (MINECO) through Grant DPI2015-71645-P.

  10. Design of organic complementary circuits and systems on foil

    CERN Document Server

    Abdinia, Sahel; Cantatore, Eugenio

    2015-01-01

    This book describes new approaches to fabricate complementary organic electronics, and focuses on the design of circuits and practical systems created using these manufacturing approaches. The authors describe two state-of-the-art, complementary organic technologies, characteristics and modeling of their transistors and their capability to implement circuits and systems on foil. Readers will benefit from the valuable overview of the challenges and opportunities that these extremely innovative technologies provide. ·         Demonstrates first circuits implemented using specific complementary organic technologies, including first printed analog to digital converter, first dynamic logic on foil and largest complementary organic circuit ·         Includes step-by-step design from single transistor level to complete systems on foil ·         Provides a platform for comparing state-of-the-art complementary organic technologies and for comparing these with other similar technologies, spec...

  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. Propulsive performance of pitching foils with variable chordwise flexibility

    Science.gov (United States)

    Zeyghami, Samane; Moored, Keith; Lehigh University Team

    2017-11-01

    Many swimming and flying animals propel themselves efficiently through water by oscillating flexible fins. These fins are not homogeneously flexible, but instead their flexural stiffness varies along their chord and span. Here we seek to evaluate the effect stiffness profile on the propulsive performance of pitching foils. Stiffness profile characterizes the variation in the local fin stiffness along the chord. To this aim, we developed a low order model of a functionally-graded material where the chordwise flexibility is modeled by two torsional springs along the chordline and the stiffness and location of the springs can be varied arbitrarily. The torsional spring structural model is then strongly coupled to a boundary element fluid model to simulate the fluid-structure interactions. Keeping the leading edge kinematics unchanged, we alter the stiffness profile of the foil and allow it to swim freely in response to the resulting hydrodynamic forces. We then detail the dependency of the hydrodynamic performance and the wake structure to the variations in the local structural properties of the foil.

  13. Electroplating of Uranium -Foil Target With Ni And Zn

    International Nuclear Information System (INIS)

    Husna AI Hasa, Muhammad; Suripto, Asmedi

    2001-01-01

    The uranium foil target, which was produced by rolling, was subjected to preparation treatment prior to the electroplating. The electroplating produced certain plate thickness on the foil surface. The electroplating was applied to the uranium foil of 71 mm long and 46 mm wide using plating materials of Ni and Zn. The plating is intended to serve as barrier for fission fragment recoils, which are produced during irradiation. The plate thickness produced by the electroplating was measured by a micrometer and an analytical balance. The electroplating with Ni produced plate-thickness of 8,9 mm when measured by the micrometer, or 11.4 mm when measured by the analytical balance, while the Zn electroplating produced greater plate-thickness, i.e. 16.2 mm by the micrometer measurement or 13.7 mm by the analytical balance measurement. The current efficiency of the electroplating was 62 % for Ni and 80 % for Zn. It was observed that the optimum condition for the electroplating depended on the plating materials, plating time, and current density. The plate-thickness produced under the optimum condition was 7-15 mm at 15 mA/cm 2 for Ni and ]0 mA/cm 2 for Zn with plating time of 60 minutes

  14. Comparison of EXAFS Foil Spectra from Around the World

    International Nuclear Information System (INIS)

    Kelly, S.D.; Bare, S.R.; Greenlay, N.; Azevedo, G.; Balasubramanian, M.; Barton, D.; Chattopadhyay, S.; Fakra, S.; Johannessen, B.; Newville, M.; Pena, J.; Pokrovski, G.S; Proux, O.; Priolkar, K.; Ravel, B.; Webb, S.M.

    2010-01-01

    The EXAFS spectra of Cu and Pd foil from many different beamlines and synchrotrons are compared to address the dependence of the amplitude reduction factor (S 0 2 ) on beamline specific parameters. Even though S 0 2 is the same parameter as the EXAFS coordination number, the value for S 0 2 is given little attention, and is often unreported. The S 0 2 often differs for the same material due to beamline and sample attributes, such that no importance is given to S 0 2 -values within a general range of 0.7 to 1.1. EXAFS beamlines have evolved such that it should now be feasible to use standard S 0 2 values for all EXAFS measurements of a specific elemental environment. This would allow for the determination of the imaginary energy (Ei) to account for broadening of the EXAFS signal rather than folding these errors into an effective S 0 2 -value. To test this concept, we model 11 Cu-foil and 6 Pd-foil EXAFS spectra from around the world to compare the difference in S 0 2 - and Ei-values.

  15. Method for fabrication of ceramic dielectric films on copper foils

    Science.gov (United States)

    Ma, Beihai; Narayanan, Manoj; Dorris, Stephen E.; Balachandran, Uthamalingam

    2015-03-10

    The present invention provides a method for fabricating a ceramic film on a copper foil. The method comprises applying a layer of a sol-gel composition onto a copper foil. The sol-gel composition comprises a precursor of a ceramic material suspended in 2-methoxyethanol. The layer of sol-gel is then dried at a temperature up to about 250.degree. C. The dried layer is then pyrolyzed at a temperature in the range of about 300 to about 450.degree. C. to form a ceramic film from the ceramic precursor. The ceramic film is then crystallized at a temperature in the range of about 600 to about 750.degree. C. The drying, pyrolyzing and crystallizing are performed under a flowing stream of an inert gas. In some embodiments an additional layer of the sol-gel composition is applied onto the ceramic film and the drying, pyrolyzing and crystallizing steps are repeated for the additional layer to build up a thicker ceramic layer on the copper foil. The process can be repeated one or more times if desired.

  16. Ion bombardment effects on the fatigue life of stainless steel under simulated fusion first wall conditions

    International Nuclear Information System (INIS)

    Kohse, G.; Harling, O.K.

    1983-01-01

    Pressurized tube specimens have been exposed to simultaneous multi-energy surface ion bombardment, fast neutron irradiation and stress and temperature cycling, in a simulation of a possible fusion reactor first wall environment. After ion bombardments equivalent to months-years of reactor operation and up to 30,000 cycles, no detrimental effects on post-irradiation fatigue life were found. The ion damage is found to enhance surface cracking, but this effect is limited to the several micron surface layer in which the ions are implanted

  17. Effects of low and high energy ion bombardment on ETFE polymer

    Science.gov (United States)

    Minamisawa, R. A.; De Almeida, A.; Abidzina, V.; Parada, M. A.; Muntele, I.; Ila, D.

    2007-04-01

    The polymer ethylenetetrafluoroethylene (ETFE) is used as anti-adherent coatings for food packages and radiation dosimeters. In this work, we compare the damage induced in ETFE bombarded with 100 keV Si ions with that induced by 1 MeV proton bombardment. The damage depends on the type, energy and intensity of the irradiation. Irradiated films were analyzed with optical absorption photospectrometry, Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy to determine the chemical nature of the structural changes caused by ion irradiation. Computer simulations were performed to evaluate the radiation damage.

  18. Statistical characterization of surface defects created by Ar ion bombardment of crystalline silicon

    International Nuclear Information System (INIS)

    Ghazisaeidi, M.; Freund, J. B.; Johnson, H. T.

    2008-01-01

    Ion bombardment of crystalline silicon targets induces pattern formation by the creation of mobile surface species that participate in forming nanometer-scale structures. The formation of these mobile species on a Si(001) surface, caused by sub-keV argon ion bombardment, is investigated through molecular dynamics simulation of Stillinger-Weber [Phys. Rev. B 31, 5262 (1985)] silicon. Specific criteria for identifying and classifying these mobile atoms based on their energy and coordination number are developed. The mobile species are categorized based on these criteria and their average concentrations are calculated

  19. Effect of helium ion bombardment on hydrogen behaviour in stainless steel

    International Nuclear Information System (INIS)

    Guseva, M.I.; Stolyarova, V.G.; Gorbatov, E.A.

    1987-01-01

    The effect of helium ion bombardment on hydrogen behaviour in 12Kh18N10T stainless steel is investigated. Helium and hydrogen ion bombardment was conducted in the ILU-3 ion accelerator; the fluence and energy made up 10 16 -5x10 17 cm -2 , 30 keV and 10 16 -5x10 18 cm -2 , 10 keV respectively. The method of recoil nuclei was used for determination of helium and hydrogen content. Successive implantation of helium and hydrogen ions into 12Kh18N10T stainless steel results in hydrogen capture by defects formed by helium ions

  20. Ion bombardment induced surface topography modification of clean and contaminated single crystal Cu and Si

    International Nuclear Information System (INIS)

    Lewis, G.W.; Kiriakides, G.; Carter, G.; Nobes, M.J.

    1982-01-01

    Among the several factors which lead to depth resolution deterioration during sputter profiling, surface morphological modification resulting from local differences of sputtering rate can be important. This paper reports the results of direct scanning, electron microscopic studies obtained quasi-dynamically during increasing fluence ion bombardment of the evolution of etch pit structures on Si and Cu, and how such elaboration may be suppressed. It also reports on the elaboration of contaminant-induced cone generation for different ion species bombardment. The influence of such etch pit and cone generation on achievable depth resolution is assessed. (author)

  1. The influence of ion bombardment on emission properties of carbon materials

    International Nuclear Information System (INIS)

    Chepusov, Alexander; Komarskiy, Alexander; Kuznetsov, Vadim

    2014-01-01

    When electric-vacuum device works its cathode surface experiences bombardment with ions of residual gases. Effects of ion bombardment impact on surface of field emission cathodes made of carbon materials may essentially change emission properties of such cathodes. It changes emission start electric field strength, voltage vs. current characteristic of material, its relief and electron structure of the surface layer. Field emission cathode operating mode, variation of radiation doses allow to obtain both good effects: maximal electric current, surface recovery – and negative ones: the worst emission properties and surface destruction, amorphization.

  2. The influence of ion bombardment on emission properties of carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Chepusov, Alexander, E-mail: chepusov@iep.uran.ru [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation); Ural Federal University, 620002, 19 Mira Street, Ekaterinburg (Russian Federation); Komarskiy, Alexander, E-mail: aakomarskiy@gmail.com [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation); Ural Federal University, 620002, 19 Mira Street, Ekaterinburg (Russian Federation); Kuznetsov, Vadim, E-mail: kuznetsov@iep.uran.ru [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation)

    2014-07-01

    When electric-vacuum device works its cathode surface experiences bombardment with ions of residual gases. Effects of ion bombardment impact on surface of field emission cathodes made of carbon materials may essentially change emission properties of such cathodes. It changes emission start electric field strength, voltage vs. current characteristic of material, its relief and electron structure of the surface layer. Field emission cathode operating mode, variation of radiation doses allow to obtain both good effects: maximal electric current, surface recovery – and negative ones: the worst emission properties and surface destruction, amorphization.

  3. Study on evolution of gases from fluoropolymer films bombarded with heavy ions

    International Nuclear Information System (INIS)

    Minamisawa, Renato Amaral; Zimmerman, Robert Lee; Budak, Satilmis; Ila, Daryush

    2008-01-01

    Ion beam bombardment provides a unique way of material modification by inducing a high degree of localized electronic excitation. The ion track, or affected volume along the ion path through the material is related to the total damage and possible structural changes. Here we study the evolution of gases emitted by poly(tetrafluorethylene-co-perfluoro-(propyl vinyl ether)) (PFA) fluoropolymer bombarded with MeV gold ions. The gas was monitored by a residual gas analyzer (RGA), as a function of the ion fluence. Micro-Raman, atomic force microscopy and optical absorption were used to analyze the chemical structure changes and sputtering yield

  4. Cryogenic foam insulation: Abstracted publications

    Science.gov (United States)

    Williamson, F. R.

    1977-01-01

    A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

  5. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Z.; Przybytniak, G.; Nowicki, A.

    2011-01-01

    Complete text of publication follows. The computer simulations based on Monte Carlo method and the ModeCEB software program were carried out in connection with EB radiation set-up for crosslinking of electrical wire and cable insulation, located at the Center for Radiation Research and Technology of the Institute of Nuclear Chemistry and Technology. The theoretical predictions for absorbed dose distribution in irradiated electrical wire and cable insulation caused by scanned EB were compared to the experimental results of irradiation which were carried out in the experimental set-up based on ILU 6 electron accelerator, which is characterized by the following parameters: Electron energy 0.5-2.0 MeV; Average beam current 40-10 mA, pulse duration 400 μs; Width of scanning up to 80 cm; Scan frequency up to 50 Hz. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for different process parameters; electrical wire and cable geometry (thickness of insulation layers and cupper wire diameter), type of polymer isolation, electron energy, energy spread, geometry of electron beam and electrical wire and cable distribution at irradiation zone. The geometry of electron beam distribution in irradiation zone was measured using TVA and PVC foil dosimeters for electron energy range available in ILU 6 accelerator. The temperature rise of irradiated electrical wire and irradiation homogeneity were evaluated for different experimental conditions to optimize process parameters. The obtained results of computer simulation were supported by experimental data of dose distribution based on gel-fraction measurements. Such agreement indicates that computer simulation ModeCEB is correct and sufficient for modelling of absorbed dose distribution in multi-layer circular objects irradiated with scanned electron beams. Acknowledgement: The R and D activities are supported by the European

  6. Saving millions by thermal insulation; Miljoenen besparen door goede isolatie

    Energy Technology Data Exchange (ETDEWEB)

    Van der Velden, U. [Nederlands Centrum voor Technische Isolatie NCTI, spijkenisse (Netherlands)

    2009-07-15

    Corrosion under insulation (CUI) can be reduced by the application of a correctly designed, installed and maintained insulation system. In refrigeration plants a heat flow will occur from the warm outside towards the cold inside. Hot air, containing more moisture, will be distributed to the cold components of the installation, such as separators, intermediate coolers, piping and valves, thus not only facilitating CUI, but also seriously compromising the thermal performance of the system. Furthermore, this moisture could condensate or freeze and compromise the integrity of the installation. Insulation in cold systems is built up with closed cell materials, such as elastomeric foam, PIR (polyisocyanurate) or cellular glass. On the outside a vapor barrier (e.g. reinforced aluminium foil) is essential to prevent hot moist air from penetrating the system. For protection against weather influences and/or mechanical damage, the system should be finished with a (non)metal cladding. [Dutch] Corrosie onder isolatie (CUI) kan worden beperkt door toepassing van een correct ontworpen, geinstalleerd en onderhouden isolatiesysteem. Bij koude-isolatiesystemen treedt een warmtestroom van buiten naar binnen op. Warme lucht - die meer vocht bevat - dringt naar installatiecomponenten, zoals afscheiders, tussenkoelers, leidingen en afstuiters, waarbij niet alleen het risico op CUI aanzienlijk toeneemt, maar ook de isolatiewaarde van het systeem gereduceerd wordt. Vocht kan hierbij ook nog condenseren of bevriezen en de integriteit van de hele installatie in gevaar brengen. Koude-isolatiesystemen dienen te worden opgebouwd met gesloten cel-materiaal, zoals elastomeer schuim, PIR (polyisocyanurate) of cellulair glas. Het systeem dient aan de buitenzijde te worden voorzien van een dampremmende laag (van bijvoorbeeld versterkt aluminiumfolie) om binnendringend vocht te blokkeren. In buitencondities moet het systeem worden voorzien van een (metalen of niet-metalen) eindafwerking, die

  7. A thermal spike model of the amorphization of insulators by high-energy heavy-ion irradiation

    International Nuclear Information System (INIS)

    Szenes, G.

    1995-01-01

    Recently, experimental data on magnetic insulators irradiated with swift heavy ions were analyzed by a new thermal spike model and good quantitative agreement was achieved. Analytical expressions were given for the evolution of latent tracks with the electronic stopping power S e of bombarding ions and a relation between the thermal properties of the target and the threshold value of S e was proposed and proved experimentally. In the present paper, after a brief review of the model, the temperature dependence of latent track formation is discussed and the predictions of the model are compared with the available experimental results

  8. Avalanches in insulating gases

    International Nuclear Information System (INIS)

    Verhaart, H.F.A.

    1982-01-01

    Avalanches of charged particles in gases are often studied with the ''electrical method'', the measurement of the waveform of the current in the external circuit. In this thesis a substantial improvement of the time resolution of the measuring setup, to be used for the electrical method, is reported. The avalanche is started by an N 2 -laser with a pulse duration of only 0.6 ns. With this laser it is possible to release a high number of primary electrons (some 10 8 ) which makes it possible to obtain sizeable signals, even at low E/p values. With the setup it is possible to analyze current waveforms with a time resolution down to 1.4 ns, determined by both the laser and the measuring system. Furthermore it is possible to distinguish between the current caused by the electrons and the current caused by the ions in the avalanche and to monitor these currents simultaneously. Avalanche currents are measured in N 2 , CO 2 , O 2 , H 2 O, air of varying humidity, SF 6 and SF 6 /N 2 mixtures. Depending on the nature of the gas and the experimental conditions, processes as diffusion, ionization, attachment, detachment, conversion and secondary emission are observed. Values of parameters with which these processes can be described, are derived from an analysis of the current waveforms. For this analysis already published theories and new theories described in this thesis are used. The drift velocity of both the electrons and the ions could be easily determined from measured avalanche currents. Special attention is paid to avalanches in air becasue of the practical importance of air insulation. (Auth.)

  9. Influence of ion bombardment on growth and properties of PLD created DLC films

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Písařík, Petr; Kocourek, Tomáš; Zemek, Josef; Lukeš, J.

    2013-01-01

    Roč. 110, č. 4 (2013), s. 943-947 ISSN 0947-8396 R&D Projects: GA MŠk LD12069 Institutional research plan: CEZ:AV0Z10100522 Keywords : DLC * ion bombardment * sp3 /sp2 * thin films * PLD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.694, year: 2013

  10. High Energy Ion Bombardment Simulation Facility at the University of Pittsburgh

    International Nuclear Information System (INIS)

    McGruer, J.N.; Choyke, W.J.; Doyle, N.J.; Spitznagel, J.A.

    1975-01-01

    The High Energy Ion Bombardment Simulation (HEIBS) Facility located at the University of Pittsburgh is now operational. The E-22 tandem accelerator of the Nuclear Physics Laboratory, fitted with a UNIS source, provides the heavy high energy ions. An auxiliary Van de Graaff accelerator is used for the simultaneous production of He ions. Special features of the simulation laboratory are reported

  11. Theoretical simulations of atomic and polyatomic bombardment of an organic overlayer on a metallic substrate

    CERN Document Server

    Krantzman, K D; Delcorte, A; Garrison, B J

    2003-01-01

    Our previous molecular dynamics simulations on initial test systems have laid the foundation for understanding some of the effects of polyatomic bombardment. In this paper, we describe simulations of the bombardment of a more realistic model system, an overlayer of sec-butyl-terminated polystyrene tetramers on a Ag left brace 1 1 1 right brace substrate. We have used this model system to study the bombardment with Xe and SF sub 5 projectiles at kinetic energies ranging from 0.50 to 5.0 keV. SF sub 5 sputters more molecules than Xe, but a higher percentage of these are damaged rather than ejected intact when the bombarding energy is greater than 0.50 keV. Therefore, at energies comparable to experimental values, the efficiency, measured as the yield-to-damage ratio, is greater with Xe than SF sub 5. Stable and intact molecules are generally produced by upward moving substrate atoms, while fragments are produced by the upward and lateral motion of reflected projectile atoms and fragments from the target molecul...

  12. A note on the random walk theory of recoil movement in prolonged ion bombardment

    International Nuclear Information System (INIS)

    Koponen, Ismo

    1994-01-01

    A characteristic function is derived for the probability distribution of final positions of recoil atoms in prolonged ion bombardment of dense matter. The derivation is done within the framework of Poissonian random walk theory using a jump distribution, which is somewhat more general than those studied previously. ((orig.))

  13. Probabilities of symmetric and asymmetric fission in the proton bombardment of Th{sup 232}

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, B J [Atomic Energy Research Establishment, Chemistry Div., Harwell (United Kingdom); Brown, F; Butler, J P

    1957-08-01

    The ratio of symmetric to asymmetric fission in the proton bombardment of Th{sup 232} does not rise steadily with increasing proton energy; a periodic decrease in superposed upon the over-all increase. This is attributed to the changing pattern of various fission reactions, (p,f), (p,nf), etc. (author)

  14. Materials surface modification by plasma bombardment under simultaneous erosion and redeposition conditions

    International Nuclear Information System (INIS)

    Hirooka, Y.; Goebel, D.M.; Conn, R.W.

    1986-07-01

    The first in-depth investigation of surface modification of materials by continuous, high-flux argon plasma bombardment under simultaneous erosion and redeposition conditions have been carried out for copper and 304 stainless steel using the PISCES facility. The plasma bombardment conditions are: incident ion flux range from 10 17 to 10 19 ions sec -1 cm -2 , total ion fluence is controlled between 10 19 and 10 22 ions cm -2 , electron temperature range from 5 to 15 eV, and plasma density range from 10 11 to 10 13 cm -3 . The incident ion energy is 100 eV. The sample temperature is between 300 and 700K. Under redeposition dominated conditions, the material erosion rate due to the plasma bombardment is significantly smaller (by a factor up to 10) than that can be expected from the classical ion beam sputtering yield data. It is found that surface morphologies of redeposited materials strongly depend on the plasma bombardment condition. The effect of impurities on surface morphology is elucidated in detail. First-order modelings are implemented to interpret the reduced erosion rate and the surface evolution. Also, fusion related surface properties of redeposited materials such as hydrogen reemission and plasma driven permeation have been characterized

  15. Stable transformation via particle bombardment in two different soybean regeneration systems.

    Science.gov (United States)

    Sato, S; Newell, C; Kolacz, K; Tredo, L; Finer, J; Hinchee, M

    1993-05-01

    The Biolistics(®) particle delivery system for the transformation of soybean (Glycine max L. Merr.) was evaluated in two different regeneration systems. The first system was multiple shoot proliferation from shoot tips obtained from immature zygotic embryos of the cultivar Williams 82, and the second was somatic embryogenesis from a long term proliferative suspension culture of the cultivar Fayette. Bombardment of shoot tips with tungsten particles, coated with precipitated DNA containing the gene for β-glucuronidase (GUS), produced GUS-positive sectors in 30% of the regenerated shoots. However, none of the regenerants which developed into plants continued to produce GUS positive tissue. Bombardment of embryogenic suspension cultures produced GUS positive globular somatic embryos which proliferated into GUS positive somatic embryos and plants. An average of 4 independent transgenic lines were generated per bombarded flask of an embryogenic suspension. Particle bombardment delivered particles into the first two cell layers of either shoot tips or somatic embryos. Histological analysis indicated that shoot organogenesis appeared to involve more than the first two superficial cell layers of a shoot tip, while somatic embryo proliferation occurred from the first cell layer of existing somatic embryos. The different transformation results obtained with these two systems appeared to be directly related to differences in the cell types which were responsible for regeneration and their accessibility to particle penetration.

  16. Effects of low-energy ion beam bombardment on metal oxides

    International Nuclear Information System (INIS)

    Sullivan, J.L.; Saied, S.O.; Choudhury, T.

    1993-01-01

    This paper describes a study of Ar ion bombardment damage in metal oxides. In the energy range 1 to 5 keV, preferential oxygen removal and reduction of the oxides was found to depend on ion current density, but to be independent of beam energy. (author)

  17. Proposals for the heating mechanism of an electron-bombarded body

    International Nuclear Information System (INIS)

    Geller, R.; Yerouchalmi, F.

    1967-01-01

    When a thermally isolated target in vacuum is bombarded by an electron beam the target becomes red. In this paper we try a heuristic explanation indicating how the kinetic power of the beam may be transformed into radiation power controlled by Stefan law. (authors) [fr

  18. Bombardment of gas molecules on single graphene layer at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Murugesan, Ramki [School of Mechanical and Aerospace Engineering, Gyeongsang National University, Jinju, Gyeongnam 660-701 (Korea, Republic of); Park, Jae Hyun [Department of Aerospace and System Engineering and Research Center for Aircraft Parts Technology, Gyeongsang National University, Jinju, Gyeongnam 660-701 (Korea, Republic of); Ha, Dong Sung [Future Propulsion Center, Agency for Defense Development, Daejeon 305-600 (Korea, Republic of)

    2014-12-09

    Graphite is widely used as a material for rocket-nozzle inserts due to its excellent thermo-physical properties as well as low density. During the operation of rockets, the surface of the graphite nozzle is subjected to very high heat fluxes and the undesirable erosion of the surface occurs due to the bombardment of gas molecules with high kinetic energy, which causes a significant reduction of nozzle performance. However, the understanding and quantification of such bombardment is not satisfactory due to its complexity: The bond breaking-forming happens simultaneously for the carbon atoms of graphene, some gas molecules penetrate through the surface, some of them are reflected from the surface, etc. In the present study, we perform extensive molecular dynamics (MD) simulations to examine the bombardment phenomena in high temperature environment (several thousand Kelvin). Advanced from the previous studies that have focused on the bombardment by light molecules (e.g., H{sub 2}), we will concentrate on the impact by realistic molecules (e.g., CO{sub 2} and H{sub 2}O). LAMMPS is employed for the MD simulations with NVE ensemble and AIREBO potential for graphene. The molecular understanding of the interaction between graphene and highly energetic gas molecules will enable us to design an efficient thermo-mechanical protection system.

  19. Ion bombardment damage in a modified Fe-9Cr-1Mo steel

    International Nuclear Information System (INIS)

    Farrell, K.; Lee, E.H.

    1984-01-01

    A normalized-and-tempered Fe-9Cr-1Mo steel, with small Nb and V additions, was bombarded with 4-MeV iron ions to 100 dpa at 400, 450, 500, 550, and 600 0 C. Major damage feature was dislocation tangles which coarsened with increasing bombardment temperature. Sparse cavities were heterogeneously distributed at 500 and 550 0 C. Incorporation of helium and deuterium simultaneously in the bombardments at rates of 10 and 45 appM/dpa, respectively, introduced very high concentrations of small cavities at all temperatures, many of them on grain boundaries. These cavities were shown to be promoted by helium. A small fraction of the matrix cavities exhibited bias-driven growth at 500 and 550 0 C, with swelling 0 C higher than the peak swelling temperature found in neutron irradiations, which is compatible with the higher damage rate used in the ion bombardments. High concentrations of subgrain boundaries and dislocations resulting from the heat treatment, and unbalanced cavity and dislocation sink strengths in the damage structures contribute to the swelling resistance. Such resistance may not be permanent. High densities of bubbles on grain boundaries indicate a need for helium embrittlement tests

  20. Modeling the reduction of gross lithium erosion observed under high-flux deuterium bombardment

    NARCIS (Netherlands)

    Abrams, T.; Jaworski, M. A.; Kaita, R.; Nichols, J. H.; Stotler, D. P.; De Temmerman, G.; van den Berg, M. A.; van der Meiden, H. J.; Morgan, T. W.

    2015-01-01

    Abstract Both thin (<1 μm) and thick (∼500 μm) lithium films under high-flux deuterium and neon plasma bombardment were studied in the linear plasma device Magnum-PSI at ion fluxes >1024 m−2 s−1 and surface temperatures <700 °C.

  1. Erosion of lithium coatings on TZM molybdenum and graphite during high-flux plasma bombardment

    NARCIS (Netherlands)

    Abrams, T.; Jaworski, M. A.; Kaita, R.; Stotler, D. P.; De Temmerman, G.; Morgan, T. W.; van den Berg, M. A.; van der Meiden, H. J.

    2014-01-01

    Abstract The rate at which Li films will erode under plasma bombardment in the NSTX-U divertor is currently unknown. It is important to characterize this erosion rate so that the coatings can be replenished before they are completely depleted. An empirical formula for the Li erosion rate as a

  2. Emission of positive oxygen ions from ion bombardment of adsorbate-covered metal surfaces

    International Nuclear Information System (INIS)

    Kaurin, M.G.

    1989-01-01

    During ion bombardment of metal surfaces, collision cascades can result in the emission of sputtered secondary ions. Recent experiments, however, have suggested that the emission of positive ions of electronegative adsorbates can result from electronic processes rather than from processes involving elastic collisions. This dissertation presents the results of experiments studying the emission of positive oxygen ions from oxygen- and carbon-monoxide-covered transition metal surfaces during bombardment by 25-250 keV ions of neon, argon, and krypton. The systems studied may be grouped into four categories. For a nickel substrate with adsorbed oxygen, the emission of positive oxygen ions proceeds through collision cascades. For titanium and niobium with adsorbed oxygen, the emission of positive oxygen ions is proportional to the primary ion velocity, consistent with emission from electronic processes; for a given primary ion velocity, the oxygen ion yield is independent of primary ion species. For substrates of molybdenum and tungsten, the oxygen yield is proportional to primary ion velocity, but the yield also depends on the primary ion species for a given primary ion velocity in a manner that is consistent with emission resulting from electronic processes. For these two groups, except for titanium, the yields during neon ion bombardment do not extrapolate (assuming linearity with primary ion velocity) to a nonzero value at zero beam velocity. The magnitude of the oxygen ion yields from these targets is not consistent with that expected if the emission were induced by secondary electrons emitted during the ion bombardment

  3. Bombardment-induced compositional change with alloys, oxides, and oxysalts. 1

    International Nuclear Information System (INIS)

    Kelly, R.

    1989-01-01

    A review of the role of surface binding energies in bombardment-induced compositional change with alloys, oxides and oxysalts is presented. The concepts of preferential sputtering and compositional change may or may not coincide; their differences are clarified. 77 refs.; 12 figs.; 4 tabs

  4. Particle bombardment and the genetic enhancement of crops: myths and realities

    NARCIS (Netherlands)

    Altpeter, F.; Baisakh, N.; Beachy, R.; Bock, R.; Capell, T.; Christou, P.; Daniell, H.; Datta, K.; Datta, S.; Dix, P.J.; Fauquet, C.; Huang, N.; Kohli, A.; Mooibroek, H.; Nicholson, L.; Nguyen, T.T.; Nugent, G.; Raemakers, C.J.J.M.; Romano, A.; Somers, D.A.; Stoger, E.; Taylor, N.; Visser, R.G.F.

    2005-01-01

    DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA

  5. Measures to alleviate the back bombardment effect of thermionic rf electron gun

    International Nuclear Information System (INIS)

    Huang, Y.; Xie, J.

    1991-01-01

    Thermionic rf electron gun finds application as a high brightness electron source for rf linacs. However, cathode heating from back-bombardment effect causes a ramp in the macro-pulse beam current and limit the usable pulse width. Three methods: ring cathode, magnetic deflection and laser assisted heating are studied in theory and in experiment. The results of these studies are reported

  6. Direct thermal effects of the Hadean bombardment did not limit early subsurface habitability

    Science.gov (United States)

    Grimm, R. E.; Marchi, S.

    2018-03-01

    Intense bombardment is considered characteristic of the Hadean and early Archean eons, yet some detrital zircons indicate that near-surface water was present and thus at least intervals of clement conditions may have existed. We investigate the habitability of the top few kilometers of the subsurface by updating a prior approach to thermal evolution of the crust due to impact heating, using a revised bombardment history, a more accurate thermal model, and treatment of melt sheets from large projectiles (>100 km diameter). We find that subsurface habitable volume grows nearly continuously throughout the Hadean and early Archean (4.5-3.5 Ga) because impact heat is dissipated rapidly compared to the total duration and waning strength of the bombardment. Global sterilization was only achieved using an order of magnitude more projectiles in 1/10 the time. Melt sheets from large projectiles can completely resurface the Earth several times prior to ∼4.2 Ga but at most once since then. Even in the Hadean, melt sheets have little effect on habitability because cooling times are short compared to resurfacing intervals, allowing subsurface biospheres to be locally re-established by groundwater infiltration between major impacts. Therefore the subsurface is always habitable somewhere, and production of global steam or silicate-vapor atmospheres are the only remaining avenues to early surface sterilization by bombardment.

  7. Kinetics of interaction from low-energy-ion bombardment of surfaces

    International Nuclear Information System (INIS)

    Horton, C.C.

    1988-01-01

    The kinetics of interaction from low energy oxygen ion bombardment of carbon and Teflon surfaces have been investigated. The surfaces were bombarded with 4.5 to 93 eV oxygen ions and emitted species were observed with a mass spectrometer. To obtain the kinetic information, the ion beam was square pulse modulated and reaction products were observed as a function of time. The kinetic information is contained in the response of the emitted species to the pulsed ion beam. Oxygen bombardment of carbon produced CO in three parallel branches with each following an adsorption-desorption process. The fast branch, with a rate constants of 12,000/sec, appeared to be sputter induced an was absent below about 19 eV. The medium and slow branches, with rate constants of 850/sec and 45/sec respectively, has little energy dependence and appeared to be due to chemical sputtering from two sites. The ratio of the fraction of the medium branch to that of the slow was constant at 1:3. The bombardment of Teflon produced CF in two parallel branches, with one following a series process and the other an adsorb-desorb process. The rate constant of the other branch were 22,000/sec and 7,000/sec and the rate constant of the other branch was 90/sec. The total signal fell monotonically with decreasing ion energy with the fraction for each branch holding constant at 71% for the series and 29% for the adsorb-desorb

  8. Effect of Ar bombardment on the electrical and optical properties of ...

    Indian Academy of Sciences (India)

    The influence of low-energy Ar ion beam irradiation on both electrical and optical properties of low-density polyethylene (LDPE) films is presented. The polymer films were bombarded with 320 keV Ar ions with fuences up to 1 × 10 15 cm − 2 . Electrical properties of LDPE films were measured and the effect of ion ...

  9. Electrical insulators for the theta-pinch fusion reactor

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1976-01-01

    The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application

  10. Thermal Performance Testing of Cryogenic Multilayer Insulation with Silk Net Spacers

    International Nuclear Information System (INIS)

    Johnson, W L; Frank, D J; Nast, T C; Fesmire, J E

    2015-01-01

    Early comprehensive testing of cryogenic multilayer insulation focused on the use of silk netting as a spacer material. Silk netting was used for multiple test campaigns that were designed to provide baseline thermal performance estimates for cryogenic insulation systems. As more focus was put on larger systems, the cost of silk netting became a deterrent and most aerospace insulation firms were using Dacron (or polyester) netting spacers by the early 1970s. In the midst of the switch away from silk netting there was no attempt to understand the difference between silk and polyester netting, though it was widely believed that the silk netting provided slightly better performance. Without any better reference for thermal performance data, the silk netting performance correlations continued to be used. In order to attempt to quantify the difference between the silk netting and polyester netting, a brief test program was developed. The silk netting material was obtained from Lockheed Martin and was tested on the Cryostat-100 instrument in three different configurations, 20 layers with both single and double netting and 10 layers with single netting only. The data show agreement within 15 - 30% with the historical silk netting based correlations and show a substantial performance improvement when compared to previous testing performed using polyester netting and aluminum foil/fiberglass paper multilayer insulation. Additionally, the data further reinforce a recently observed trend that the heat flux is not directly proportional to the number of layers installed on a system. (paper)

  11. Hydrogen pumping and release by graphite under high flux plasma bombardment

    International Nuclear Information System (INIS)

    Hirooka, Y.; Leung, W.K.; Conn, R.W.; Goebel, D.M.; LaBombard, B.; Nygren, R.; Wilson, K.L.

    1988-01-01

    Inert gas (helium or argon) plasma bombardment has been found to increase the surface gas adsorptivity of isotropic graphite (POCO-graphite), which can then getter residual gases in a high vacuum system. The inert gas plasma bombardment was carried out at a flux ≅ 1 x 10 18 ions s -1 cm -2 to a fluence of the order of 10 21 ions/cm 2 and at temperatures around 800 0 C. The gettering capability of graphite can be easily recovered by repeating inert gas plasma bombardment. The activated graphite surface exhibits a smooth, sponge-like morphology with significantly increased pore openings, which correlates with the observed increase in the surface gas adsorptivity. The activated graphite surface has been observed to pump hydrogen plasma particles as well. From calibrated H-alpha measurements, the dynamic hydrogen retention capacity is evaluated to be as large as 2 x 10 18 H/cm 2 at temperatures below 100 0 C and at a plasma bombarding energy of 300 eV. The graphite temperature was varied between 15 and 480 0 C. Due to the plasma particle pumping capability, hydrogen recycling from the activated graphite surface is significantly reduced, relative to that from a pre-saturated surface. A pre-saturated surface was also observed to reproducibly pump a hydrogen plasma to a concentration of 9.5 x 10 17 H/cm 2 . The hydrogen retention capacity of graphite is found to decrease with increasing temperature. A transient pumping mechanism associated with the sponge-like surface morphology is conjectured to explain the large hydrogen retention capacity. Hydrogen release behavior under helium and argon plasma bombardment was also investigated, and the result indicated the possibility of some in-pore retrapping effect. 43 refs., 11 figs

  12. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

    Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

  13. Personnel neutron dosimetry applications of track-size distributions on electrochemically etched CR-39 foils

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.G.; Westermark, J.

    1988-01-01

    The track-size distribution on electrochemically etched CR-39 foils can be used to obtain some limited information on the incident neutron spectra. Track-size distributions on CR-39 foils can also be used to determine if the tracks were caused by neutrons or if they are merely background tracks (which have a significantly different track-size distribution). Identifying and discarding the high-background foils reduces the number of foils that must be etched. This also lowers the detection limit of the dosimetry system. We have developed an image analyzer program that can more efficiently determine the track density and track-size distribution, as well as read the laser-cut identification numbers on each foil. This new image analyzer makes the routine application of track-size distributions on CR-39 foils feasible. 2 refs., 3 figs

  14. Control of Oscillating Foil for Propulsion of Biorobotic Autonomous Underwater Vehicle (AUV

    Directory of Open Access Journals (Sweden)

    S. N. Singh

    2005-01-01

    Full Text Available The paper treats the question of control of a laterally and rotationally oscillating hydrofoil for the propulsion of biologically inspired robotic (biorobotic autonomous underwater vehicles (BAUVs. Sinusoidal oscillations of foils produce maneuvering and propulsive forces. The design is based on the internal model principle. Two springs are used to transmit forces from the actuators to the foil. Oscillating fins produce periodic forces, which can be used for fish-like propulsion and control of autonomous underwater vehicles (AUVs. The equations of motion of the foil include hydrodynamic lift and moment based on linear, unsteady, aerodynamic theory. A control law is derived for the lateral and rotational sinusoidal oscillation of the foil. In the closed-loop system, the lateral displacement and the rotational angle of the foil asymptotically follow sinusoidal trajectories of distinct frequencies and amplitudes independently. Simulation results are presented to show the trajectory tracking performance of the foil for different freestream velocities and sinusoidal command trajectories.

  15. The stripping foil test stand in the Linac4 transfer line

    CERN Document Server

    Weterings, W; Noulibos, R; Sillanoli, Y; van Trappen, P

    2015-01-01

    The 160 MeV H− beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H− charge-exchange injection system. It will include a stripping foil, to convert H− into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters.

  16. The stripping foil test stand in the Linac4 transfer line

    International Nuclear Information System (INIS)

    Weterings, W.; Bracco, C.; Noulibos, R.; Sillanoli, Y.; Trappen van, P.

    2015-01-01

    The 160 MeV H - beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H - charge-exchange injection system. It will include a stripping foil, to convert H - into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters. (author)

  17. Gas electron multiplier (GEM) foil test, repair and effective gain calculation

    Science.gov (United States)

    Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

    2018-06-01

    The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

  18. 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.

  19. Modeling of high-pressure generation using the laser colliding foil technique

    Energy Technology Data Exchange (ETDEWEB)

    Fabbro, R.; Faral, B.; Virmont, J.; Cottet, F.; Romain, J.P.

    1989-03-01

    An analytical model describing the collision of two foils is presented and applied to the collision of laser-accelerated foils. Numerical simulations have been made to verify this model and to compare its results in the case of laser-accelerated foils. Scaling laws relating the different parameters (shock pressure, laser intensity, target material, etc.) have been established. The application of this technique to high-pressure equation of state experiments is then discussed.

  20. Modeling of high-pressure generation using the laser colliding foil technique

    International Nuclear Information System (INIS)

    Fabbro, R.; Faral, B.; Virmont, J.; Cottet, F.; Romain, J.P.

    1989-01-01

    An analytical model describing the collision of two foils is presented and applied to the collision of laser-accelerated foils. Numerical simulations have been made to verify this model and to compare its results in the case of laser-accelerated foils. Scaling laws relating the different parameters (shock pressure, laser intensity, target material, etc.) have been established. The application of this technique to high-pressure equation of state experiments is then discussed

  1. Stripping Foil Issues for H- Injection into the CERN PSB at 160 MeV

    CERN Document Server

    Goddard, B; Bracco, C; Carli, C; Meddahi, M; Weterings, W J M

    2010-01-01

    Beam physics considerations for the stripping foil of the 160 MeV PSB H- injection systems 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 different beam loss mechanisms are quantified in the context of the aperture limits, operational considerations and collimation requirements.

  2. Positron Annihilation in Insulating Materials

    International Nuclear Information System (INIS)

    Asoka-Kumar, P; Sterne, PA

    2002-01-01

    We describe positron results from a wide range of insulating materials. We have completed positron experiments on a range of zeolite-y samples, KDP crystals, alkali halides and laser damaged SiO 2 . Present theoretical understanding of positron behavior in insulators is incomplete and our combined theoretical and experimental approach is aimed at developing a predictive understanding of positrons and positronium annihilation characteristics in insulators. Results from alkali halides and alkaline-earth halides show that positrons annihilate with only the halide ions, with no apparent contribution from the alkali or alkaline-earth cations. This contradicts the results of our existing theory for metals, which predicts roughly equal annihilation contributions from cation and anion. We also present result obtained using Munich positron microprobe on laser damaged SiO 2 samples

  3. Floquet topological insulators for sound

    Science.gov (United States)

    Fleury, Romain; Khanikaev, Alexander B.; Alù, Andrea

    2016-06-01

    The unique conduction properties of condensed matter systems with topological order have recently inspired a quest for the similar effects in classical wave phenomena. Acoustic topological insulators, in particular, hold the promise to revolutionize our ability to control sound, allowing for large isolation in the bulk and broadband one-way transport along their edges, with topological immunity against structural defects and disorder. So far, these fascinating properties have been obtained relying on moving media, which may introduce noise and absorption losses, hindering the practical potential of topological acoustics. Here we overcome these limitations by modulating in time the acoustic properties of a lattice of resonators, introducing the concept of acoustic Floquet topological insulators. We show that acoustic waves provide a fertile ground to apply the anomalous physics of Floquet topological insulators, and demonstrate their relevance for a wide range of acoustic applications, including broadband acoustic isolation and topologically protected, nonreciprocal acoustic emitters.

  4. Fermi surfaces in Kondo insulators

    Science.gov (United States)

    Liu, Hsu; Hartstein, Máté; Wallace, Gregory J.; Davies, Alexander J.; Ciomaga Hatnean, Monica; Johannes, Michelle D.; Shitsevalova, Natalya; Balakrishnan, Geetha; Sebastian, Suchitra E.

    2018-04-01

    We report magnetic quantum oscillations measured using torque magnetisation in the Kondo insulator YbB12 and discuss the potential origin of the underlying Fermi surface. Observed quantum oscillations as well as complementary quantities such as a finite linear specific heat capacity in YbB12 exhibit similarities with the Kondo insulator SmB6, yet also crucial differences. Small heavy Fermi sections are observed in YbB12 with similarities to the neighbouring heavy fermion semimetallic Fermi surface, in contrast to large light Fermi surface sections in SmB6 which are more similar to the conduction electron Fermi surface. A rich spectrum of theoretical models is suggested to explain the origin across different Kondo insulating families of a bulk Fermi surface potentially from novel itinerant quasiparticles that couple to magnetic fields, yet do not couple to weak DC electric fields.

  5. Topological insulators and topological superconductors

    CERN Document Server

    Bernevig, Andrei B

    2013-01-01

    This graduate-level textbook is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for graduate students and researchers preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with simple concepts such as Berry phases, Dirac fermions, Hall conductance and its link to topology, and the Hofstadter problem of lattice electrons in a magnetic field. It moves on to explain topological phases of matter such as Chern insulators, two- and three-dimensional topological insulators, and Majorana p-wave wires. Additionally, the book covers zero modes on vortices in topological superconductors, time-reversal topological superconductors, and topological responses/field theory and topolo...

  6. Acceleration region influence on beam parameters on stripping foil

    International Nuclear Information System (INIS)

    Samsonov, E.V.; Tomic, S.

    1999-01-01

    Some formulas describing the beam parameters on the stripping foil (SF) as a function of the radial amplitude of betatron oscillations and energy gain are derived. The results computed by these formulas are in good agreement with the results of the numerical calculations. Obtained results show that between the radial emittance and the energy spread exists parametric dependence via amplitude of radial betatron oscillations. This conclusion allows one to create a working diagram of expected beam parameters on SF. This diagram may be particularly useful for the extraction system designers since it gives relationship between parameters considered as the extraction system input parameters. (author)

  7. The preparation and characterisation of reference fission foils

    International Nuclear Information System (INIS)

    Audenhove, J. van; Bievre, P. de; Pauwels, J.; Peetermans, F.; Gallet, M.; Verbruggen, A.

    1979-01-01

    Homogeneous and accurately defined uranium and plutonium reference fissionable deposits have been prepared by vacuum deposition of fluorides. The preparation of the fluorides as well as their vacuum deposition on planetary rotating multisubstrate holders are described. The characterisation of the deposits is obtained by relative α-counting and calibration using isotope dilution mass spectrometry. The mass per square centimeter of the deposits is corrected for the border effects and the homogeneity is determined by relative α-counting of small spots. The deposits show excellent adherence and resistance to different mediums. This makes their use as permanently available reference fission foils possible. (orig.)

  8. Critical mass experiment using U-235 foils and lucite plates

    International Nuclear Information System (INIS)

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-01-01

    The main objective of this experiment was to show how the multiplication of the system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking techniques, and approach to criticality by remote operation. This experiment was designed by Tom McLaughlin in the mid seventies as part of the criticality safety course that is taught at Los Alamos Critical Experiment Facility (LACEF). The W-U-235 ratio for this experiment was 215 which is where the minimum critical mass for this configuration occurs

  9. Critical mass experiment using 235U foils and lucite plates

    International Nuclear Information System (INIS)

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-01-01

    This experiment demonstrated how the neutron multiplication of a system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking technique and approach to criticality be remote operation. This experiment was designed by McLaughlin in the mid-seventies as part of the criticality safety course that is taught at the Los Alamos Critical Experiments Facility. The H/ 235 U ratio for this experiment was 215, which is the ratio at which the minimum critical mass for this configuration occurs

  10. 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)

  11. Measurement of neutron multiplication in Pb by Mn foils

    International Nuclear Information System (INIS)

    Chen Yuan; Liu Rong; Guo Haiping; Jiang Wenmian; Shen Jian

    1994-01-01

    The Leakage neutron multiplication in bulk lead has been measured using the total absorption detector and relative method. The polyethylene sphere of 138 cm in diameter is used as the moderator and total absorption detector. The measured results from 55 Mn foils and 6 Li glass are compared. The neutron multiplication is 1.74 with the lead shell of 23.1 cm thick. The measured result is consistent with the calculated one with ANISN code and ENDF/B-6 evaluated data within the experimental error. (4 figs., 3 tabs.)

  12. Visualization and Measurement of the Deflagration of JA2 Bonded to Various Metal Foils

    Science.gov (United States)

    2016-01-01

    foil. Tapes had an acrylic -adhesive backing applied by the manufacturer. The conductive material, whether foil or tape, ran approximately ¾ the...event were obtained such that the 0.5-inch surface was facing the camera with the foil on the right edge. The thicknesses and tape/foil configuration...adhesive type, there were differences. A 2-mil Al tape was obtained from McMaster-Carr (product No. 7925A1). It had a 2- mil-thick acrylic adhesive

  13. Characteristics of a plasma flow field produced by a metal array bridge foil explosion

    Science.gov (United States)

    Junying, WU; Long, WANG; Yase, LI; Lijun, YANG; Manzoor, SULTAN; Lang, CHEN

    2018-07-01

    To improve the energy utilization efficiency of metal bridge foil explosion, and increase the function range of plasmas, array bridge foil explosion experiments with different structures were performed. A Schlieren photographic measurement system with a double-pulse laser source was used to observe the flow field of a bridge foil explosion. The evolution laws of plasmas and shock waves generated by array bridge foil explosions of different structures were analyzed and compared. A multi-phase flow calculation model was established to simulate the electrical exploding process of a metal bridge foil. The plasma equation of state was determined by considering the effect of the changing number of particles and Coulomb interaction on the pressure and internal energy. The ionization degree of the plasma was calculated via the Saha–Eggert equation assuming conditions of local thermal equilibrium. The exploding process of array bridge foils was simulated, and the superposition processes of plasma beams were analyzed. The variation and distribution laws of the density, temperature, pressure, and other important parameters were obtained. The results show that the array bridge foil has a larger plasma jet diameter than the single bridge foil for an equal total area of the bridge foil. We also found that the temperature, pressure, and density of the plasma jet’s center region sharply increase because of the superposition of plasma beams.

  14. 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.

  15. 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)

  16. Topological insulators fundamentals and perspectives

    CERN Document Server

    Ortmann, Frank; Valenzuela, Sergio O

    2015-01-01

    There are only few discoveries and new technologies in physical sciences that have the potential to dramatically alter and revolutionize our electronic world. Topological insulators are one of them. The present book for the first time provides a full overview and in-depth knowledge about this hot topic in materials science and condensed matter physics. Techniques such as angle-resolved photoemission spectrometry (ARPES), advanced solid-state Nuclear Magnetic Resonance (NMR) or scanning-tunnel microscopy (STM) together with key principles of topological insulators such as spin-locked electronic

  17. Electric fields and electrical insulation

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    2002-01-01

    The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface...... roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  18. Energy losses in magnetically insulated transmission lines due to microparticles

    International Nuclear Information System (INIS)

    Gray, E.W.; Stinnett, R.W.

    1987-01-01

    We discuss the effects of high-velocity and hypervelocity microparticles in the magnetically insulated transmission lines of multiterawatt accelerators used for particle beam fusion and radiation effects simulation. These microparticles may be a possible source for plasma production near the anode and cathode in early stages of the voltage pulse, and current carriers during and after the power pulse, resulting in power flow losses. Losses in the current pulse, due to microparticles, are estimated to be approximately 12 mA/cm 2 (0.3 kA) as a lower limit, and --0.3 A/cm 2 (7.2 kA) for microparticle initiated, anode plasma positive ion transport. We have calculated the velocities reached by these microparticles and the effects on them of Van der Waals forces. Field emission from the particles and their effects on cathode and anode plasma formation have been examined. Particle collision with the electrodes is also examined in terms of plasma production, as in the electron deposition in the particles in transit across the anode-cathode gap. Blistering of the electrode surface, thought to be due to H - bombardment was also observed and appears to be consistent with losses due to negative ions previously reported by J. P. VanDevender, R. W. Stinnett, and R. J. Anderson [App. Phys. Lett. 38, 229 (1981)

  19. Propagation Characteristics of Multilayer Hybrid Insulator-Metal-Insulator and Metal-Insulator-Metal Plasmonic Waveguides

    Directory of Open Access Journals (Sweden)

    M. Talafi Noghani

    2014-02-01

    Full Text Available Propagation characteristics of symmetrical and asymmetrical multilayer hybrid insulator-metal-insulator (HIMI and metal-insulator-metal (HMIM plasmonic slab waveguides are investigated using the transfer matrix method. Propagation length (Lp and spatial length (Ls are used as two figures of merit to qualitate the plasmonic waveguides. Symmetrical structures are shown to be more performant (having higher Lp and lower Ls, nevertheless it is shown that usage of asymmetrical geometry could compensate for the performance degradation in practically realized HIMI waveguides with different substrate materials. It is found that HMIM slab waveguide could support almost long-range subdiffraction plasmonic modes at dimensions lower than the spatial length of the HIMI slab waveguide.

  20. 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)

  1. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1986-01-01

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnel requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm 2 /mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 90 0 . This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs

  2. Nanocomposite of polystyrene foil grafted with metallaboranes for antimicrobial activity

    Science.gov (United States)

    Benkocká, Monika; Kolářová, Kateřina; Matoušek, Jindřich; Semerádtová, Alena; Šícha, Václav; Kolská, Zdeňka

    2018-05-01

    The surface of polystyrene foil (PS) was chemically modified. Firstly, the surface was pre-treated with Piranha solution. The activated surface was grafted by selected amino-compounds (cysteamine, ethylenediamine or chitosan) and/or subsequently grafted with five members of inorganic metallaboranes. Selected surface properties were studied by using various methods in order to indicate significant changes before and after individual modification steps of polymer foil. Elemental composition of surface was conducted by using X-ray photoelectron spectroscopy, chemistry and polarity by infrared spectroscopy and by electrokinetic analysis, wettability by goniometry, surface morphology by atomic force microscopy. Antimicrobial tests were performed on individual samples in order to confirm antimicrobial impact. Our results show slight antibacterial activity of PS modified with SK5 for Escherichia coli in comparison with the rest of the tested borane. On the other hand molecules of all tested metallaboranes could easier pierce through bacterial cell of Staphylococcus epidermidis due to absence of outer membrane (phospholipid bilayer). Some borane grafted on PS surface embodies the strong activity for Staphylococcus epidermidis and also for Desmodesmus quadricauda growth inhibition.

  3. Modelling Accumulator Stripper Foil Heating for ESSNUSB Facility

    CERN Document Server

    Martini, Michel

    2015-01-01

    It is proposed to use the 2.0 GeV, 5 MW proton linac, 2.86 ms long pulses at 14 Hz of the European Spallation Source [1], [2] being built in Lund, Sweden to deliver, alternately with the spallation neutron production a very intense neutrino beam to enable the discovery of leptonic CP violation. To this end the linac would be upgraded to supply, in addition to the 2.86 ms long proton pulses at 14 Hz, four 0.72 ms H short pulses at 70 Hz for neutrino production. Because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production will need to be compressed to a few s with the aid of an accumulator ring. Charge exchange injection of an H- beam from the linac will be used, the linac delivering 1.1E15 H- per pulse. This paper is about stripping foil heating considerations, emphasizing the detailed evaluation of the foil temperature over the multiple ring re-fills

  4. 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

  5. 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

  6. Hydrodynamic studies on two traveling wavy foils in tandem arrangement

    Science.gov (United States)

    Deng, Jian; Shao, Xue-Ming; Yu, Zhao-Sheng

    2007-11-01

    In this study, the hydrodynamic interactions between two tandem foils undergoing fishlike swimming motion are investigated numerically by solving the Navier-Stokes equations with the immersed-boundary method. The two foils represent two tandem propellers attached on a concept ship. The thrusts and efficiencies at three typical Strouhal numbers, i.e., St =0.4, 0.6, and 0.8, are investigated. The results show that a fish situated directly behind another one does not always undergo a lower thrust. Whether it experiences a thrust enhancement or reduction depends on the Strouhal number. At a relatively low Strouhal number (e.g., St =0.4), the usual wake drag-reduction effect predominates over the drag-enhancement effect caused by the reverse von Kármán vortices, resulting in a thrust enhancement. The opposite happens at a relatively high Strouhal number (e.g., St =0.8). The downstream fish can benefit from the upstream one by slalom between the vortices rather than through them. For the upstream fish, the thrusts and efficiencies for all Strouhal numbers studied are higher than those for a single fish when the two fish are closely spaced, and approach those for a single fish as the spacing is increased.

  7. Electrical insulation for large multiaxis superconducting magnets

    International Nuclear Information System (INIS)

    Harvey, A.R.; Rinde, J.A.

    1975-01-01

    The selection of interturn and interlayer insulation for superconducting magnets is discussed. The magnet problems of the Baseball II device are described. Manufacture of the insulation and radiation damage are mentioned. A planned experimental program is outlined

  8. Emerging Trends in Topological Insulators and Topological ...

    Indian Academy of Sciences (India)

    /fulltext/reso/022/08/0787-0800. Keywords. Superconductor, quantum Hall effect, topological insulator, Majorana fermions. Abstract. Topological insulators are new class of materials which arecharacterized by a bulk band gap like ordinary ...

  9. Investigation of /sup 16/O+/sup 27/Al reaction at bombarding energies below 5. 3 MeV/A

    Energy Technology Data Exchange (ETDEWEB)

    Wen-Qing, Shen; Yong-Tai, Zhu; Wen-Long, Zhan; Zhong-Yan, Guo; Shu-Zhi, Yin; Wei-Min, Qiao; En-Chiu, Wu

    1987-03-01

    Quasi elastic and deep inelastic collision induced by /sup 16/O+/sup 27/Al at the bombarding energies below 5.3 MeV/A have been studied in detail. Experimental angular energy atomic charge distribution and contour plots of the differential cross sections d/sup 3/sigma/dEd..cap omega..dZ on E-theta plan are presented, their evolution with the bombarding energies are analysed. The competion between quasi elastic and deep inelastic collision as a functon of the bombarding energies has been discussed.

  10. Erosion of Be and deposition of C and O due to bombardment with C{sup +} and CO{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Eckstein, W.; Goldstrass, P.; Linsmeier, Ch. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1998-01-01

    The bombardment of Be with 3 and 5 keV C{sup +} and CO{sup +} at normal incidence is investigated experimentally and by computer simulation with the program TRIDYN. The deposited amount of C and O is determined experimentally and found in good agreement with calculated data for C bombardment. Chemical erosion dominates at higher fluences for CO{sup +} bombardment. Calculations are then used to determine the sputter yield of Be at steady state conditions as a function of the plasma edge electron temperature for two C impurity concentrations in the incident D flux, typical for fusion plasmas. The fluence to reach steady state conditions is also investigated. (author)

  11. Vacuum-insulated catalytic converter

    Science.gov (United States)

    Benson, David K.

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  12. On effective holographic Mott insulators

    Energy Technology Data Exchange (ETDEWEB)

    Baggioli, Matteo; Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE), Universitat Autònoma de Barcelona,The Barcelona Institute of Science and Technology,Campus UAB, 08193 Bellaterra (Barcelona) (Spain)

    2016-12-20

    We present a class of holographic models that behave effectively as prototypes of Mott insulators — materials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.

  13. Improved DC Gun Insulator Assembly

    International Nuclear Information System (INIS)

    Neubauer, M.L.; Dudas, A.; Sah, R.; Poelker, M.; Surles-Law, K.E.L.

    2010-01-01

    Many user facilities such as synchrotron radiation light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and often exhibit poor reliability. Two technical approaches to solving this problem will be investigated. Firstly, inverted ceramics offer solutions for reduced gradients between the electrodes and ground. An inverted design will be presented for 350 kV, with maximum gradients in the range of 5-10 MV/m. Secondly, novel ceramic manufacturing processes will be studied, in order to protect triple junction locations from emission, by applying a coating with a bulk resistivity. The processes for creating this coating will be optimized to provide protection as well as be used to coat a ceramic with an appropriate gradient in bulk resistivity from the vacuum side to the air side of an HV standoff ceramic cylinder. Example insulator designs are being computer modelled, and insulator samples are being manufactured and tested

  14. On effective holographic Mott insulators

    International Nuclear Information System (INIS)

    Baggioli, Matteo; Pujolàs, Oriol

    2016-01-01

    We present a class of holographic models that behave effectively as prototypes of Mott insulators — materials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.

  15. Thermal insulation of fuel elements

    International Nuclear Information System (INIS)

    Dubrovcak, P.; Pec, V.; Pitonak, J.

    1978-01-01

    The claim of the invention concerns thermal insulation of fuel elements heated for measurement of uranium fuel physical properties. For this, layers of aluminium film and of glass fibre are wound onto the inner tube of the element cladding. The space between the inner and the outer tubes is evacuated and the tubes are spaced using spacer wires. (M.S.)

  16. 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

  17. Forming Refractory Insulation On Copper Wire

    Science.gov (United States)

    Setlock, J.; Roberts, G.

    1995-01-01

    Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

  18. Optimization design for SST-1 Tokamak insulators

    International Nuclear Information System (INIS)

    Zhang Yuanbin; Pan Wanjiang

    2012-01-01

    With the help of ANSYS FEA technique, high voltage and cryogenic proper- ties of the SST-1 Tokamak insulators were obtained, and the structure of the insulators was designed and modified by taking into account the simulation results. The simulation results indicate that the optimization structure has better high voltage insulating property and cryogenic mechanics property, and also can fulfill the qualification criteria of the SST-1 Tokamak insulators. (authors)

  19. Cylindrical cryogenic calorimeter testing of six types of multilayer insulation systems

    Science.gov (United States)

    Fesmire, J. E.; Johnson, W. L.

    2018-01-01

    Extensive cryogenic thermal testing of more than 100 different multilayer insulation (MLI) specimens was performed over the last 20 years for the research and development of evacuated reflective thermal insulation systems. From this data library, 26 MLI systems plus several vacuum-only systems are selected for analysis and comparison. The test apparatus, methods, and results enabled the adoption of two new technical consensus standards under ASTM International. Materials tested include reflectors of aluminum foil or double-aluminized Mylar and spacers of fiberglass paper, polyester netting, silk netting, polyester fabric, or discrete polymer standoffs. The six types of MLI systems tested are listed as follows: Mylar/Paper, Foil/Paper, Mylar/Net, Mylar/Blanket, Mylar/Fabric, Mylar/Discrete. Also tested are vacuum-only systems with different cold surface materials/finishes including stainless steel, black, copper, and aluminum. Testing was performed between the boundary temperatures of 78 K and 293 K (and up to 350 K) using a thermally guarded one-meter-long cylindrical calorimeter (Cryostat-100) for absolute heat flow measurement. Cold vacuum pressures include the full range from 1 × 10-6 torr to 760 torr with nitrogen as the residual gas. System variations include number of layers from one to 80 layers, layer densities from 0.5 to 5 layers per millimeter, and installation techniques such layer-by-layer, blankets (multi-layer assemblies), sub-blankets, seaming, butt-joining, spiral wrapping, and roll-wrapping. Experimental thermal performance data for the different MLI systems are presented in terms of heat flux and effective thermal conductivity. Benchmark cryogenic-vacuum thermal performance curves for MLI are given for comparison with different insulation approaches for storage and transfer equipment, cryostats, launch vehicles, spacecraft, or science instruments.

  20. Polyimide Foams Offer Superior Insulation

    Science.gov (United States)

    2012-01-01

    At Langley Research Center, Erik Weiser and his colleagues in the Advanced Materials and Processing Branch were working with a new substance for fabricating composites for use in supersonic aircraft. The team, however, was experiencing some frustration. Every time they tried to create a solid composite from the polyimide (an advanced polymer) material, it bubbled and foamed. It seemed like the team had reached a dead end in their research - until they had another idea. "We said, This isn t going to work for composites, but maybe we could make a foam out of it," Weiser says. "That was kind of our eureka moment, to see if we could go in a whole other direction. And it worked." Weiser and his colleagues invented a new kind of polyimide foam insulation they named TEEK. The innovation displayed a host of advantages over existing insulation options. Compared to other commercial foams, Weiser explains, polyimide foams perform well across a broad range of temperatures, noting that the NASA TEEK foams provide effective structural insulation up to 600 F and down to cryogenic temperatures. The foam does not burn or off-gas toxic fumes, and even at -423 F - the temperature of liquid hydrogen - the material stays flexible. The inventors could produce the TEEK foam at a range of densities, from 0.5 pounds per cubic foot up to 20 pounds per cubic foot, making the foam ideal for a range of applications, including as insulation for reusable launch vehicles and for cryogenic tanks and lines. They also developed a unique, friable balloon format for manufacturing the foam, producing it as hollow microspheres that allowed the foam to be molded and then cured into any desired shape - perfect for insulating pipes of different sizes and configurations. The team s originally unplanned invention won an "R&D 100" award, and a later form of the foam, called LaRC FPF-44 (Spinoff 2009), was named "NASA Invention of the Year" in 2007.

  1. Insulator applications in a Tokamak reactor

    International Nuclear Information System (INIS)

    Leger, D.

    1986-06-01

    Insulators, among which insulators ceramics, have great potential applications in fusion reactors. They will be used for all plasma-facing components as protection and, magnetic fusion devices being subject to large electrical currents flowing in any parts of the device, for their electrical insulating properties

  2. Friction and wear measurements of sputtered MoS/sub x/ films amorphized by ion bombardment

    International Nuclear Information System (INIS)

    Mikkelsen, N.J.; Chevallier, J.; Soerensen, G.; Straede, C.A.

    1988-01-01

    The present study presents an experimental evidence for amorphization of rf sputtered MoS/sub x/ films by ion bombardment. Even at low doses (3 x 10 15 ions/cm 2 ) of 400 keV argon ions a complete amorphization was confirmed by x-ray diffraction analysis and transmission electron microscopy. As a result of the ion bombardment the film density increased 100% to almost the bulk value for MoS 2 . The friction coefficient for ion beam amorphized MoS/sub x/ was measured to be 0.04 in agreement with the values reported for crystalline films but disagreeing considerably with the friction coefficient of 0.4 previously reported for amorphous films

  3. Films deposited from reactive sputtering of aluminum acetylacetonate under low energy ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Battaglin, Felipe Augusto Darriba; Prado, Eduardo Silva; Cruz, Nilson Cristino da; Rangel, Elidiane Cipriano, E-mail: elidiane@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil). Lab. de Plasmas Tecnologicos; Caseli, Luciano [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil). Instituto de Ciencias Ambientais, Quimicas e Farmaceuticas; Silva, Tiago Fiorini da; Tabacniks, Manfredo Harri [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

    2017-07-15

    Films were deposited from aluminum acetylacetonate (Al(acac)3 ) using a methodology involving reactive sputtering and low energy ion bombardment. The plasma was generated by the application of radiofrequency power to the powder containing electrode and simultaneously, negative pulses were supplied to the electrode where the substrates were attached. It was investigated the effect of the duty cycle of the pulses (Δ) on the properties of the coatings. Association of ion bombardment to the deposition process increased film thickness, structure reticulation and organic content. Ions from the deposition environment were implanted at the film-air interface or underneath it. Morphology and topography were altered depending on Δ. Considering the enhancement of Δ, it affected the flux of ions reaching the depositing interface and then the deposition rate, H content, crosslinking degree and surface microstructure. Alumina groups were detected in the infrared spectra, whereas the precipitation of amorphous alumina was confirmed by X-ray diffraction. (author)

  4. Low energy Ar ion bombardment damage of Si, GaAs, and InP surfaces

    International Nuclear Information System (INIS)

    Williams, R.S.

    1982-01-01

    Argon bombardment damage to (100) surfaces of Si, GaAs, and InP for sputter ion-gun potentials of 1, 2, and 3 kilovolts was studied using Rutherford backscattering. Initial damage rates and saturation damage levels were determined. Bombardment damage sensitivity increased for the sequence Si, GaAs, and InP. Saturation damage levels for Si and GaAs correspond reasonably to LSS projected range plus standard deviation estimates; damage to InP exceeded this level significantly. For an ion-gun potential of 3 keV, the initial sputter yield of P from an InP surface exceeded the sputter yield of In by four atoms per incident Ar projectile. (author)

  5. Composition and structure of ion-bombardment-induced growth cones on InP

    International Nuclear Information System (INIS)

    Malherbe, J.B.; Lakner, H.; Gries, W.H.

    1991-01-01

    The previously reported effect of low-energy (several keV) ion bombardment on the surface topography of InP was investigated by scanning transmission electron microscopy. Convergent beam electron diffraction patterns of the surface growth 'cones' induced by argon ion bombardment of (100) InP between 7 and 10 keV proved the cones to consist of crystalline InP (and not metallic indium, as has sometimes been claimed). The investigation showed that the irradiated surface region is not rendered completely amorphous but that it recrystallizes from the crystalline/amorphous interface in a columnar growth pattern, often terminating in growth cones protruding above the surface. Weak beam investigations revealed that the overwhelming majority of the cones have the orientation of the substrate. These phenomena were observed at all dose densities from 7 x 10 15 to 2 x 10 17 cm -2 . (author)

  6. Study on the growth of aligned carbon nanotubes controlled by ion bombardment

    International Nuclear Information System (INIS)

    Wang Biben; Zhang Bing; Zheng Kun; Hao Wei; Wang Wanlu; Liao Kejun

    2004-01-01

    Aligned carbon nanotubes were prepared by plasma-enhanced hot filament chemical vapor deposition using CH 4 , H 2 and NH 3 as reaction gases. It was investigated how different negative bias affects the growth of aligned carbon nanotubes. The results indicate that the average diameter of the aligned carbon nanotubes is reduced and the average length of the aligned carbon nanotubes is increased with increasing negative bias. Because of the occurrence of glow discharge, a cathode sheath forms near the substrate surface, and a number of ions are produced in it, and a very strong electrical field builds up near the substrate surface. Under the effect of the field, the strong bombardment of ions on the substrate surface will influence the growth of aligned carbon nanotubes. Combined with related theories, authors have analyzed and discussed the ion bombardment effects on the growth of the aligned carbon nanotudes

  7. The effect of incidence angle on ion bombardment induced surface topography development on single crystal copper

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.; Lewis, G.W.; Whitton, J.L.

    1982-01-01

    The fluence dependence of development of microscopic surface features, particularly etch pits, during 9 keV Ar + ion bombardment of (11,3,1) oriented Cu single crystals has been studied employing quasi-dynamic irradiation and observation techniques in a scanning electron microscope-accelerator system. 9 keV ions are observed not to produce crystallographic pyramids under all irradiation conditions for this surface, a very different result from our earlier studies with higher energy ions. The bombardment does elaborate etch pits however, the habits and growth kinetics of which depend upon both polar and azimuthal angles of ion incidence to the surface. The results are explained in terms of differential erosion of crystal planes modified by the presence of pre-existing and irradiation induces extended defects. (orig.)

  8. Ion bombardment induced smoothing of amorphous metallic surfaces: Experiments versus computer simulations

    International Nuclear Information System (INIS)

    Vauth, Sebastian; Mayr, S. G.

    2008-01-01

    Smoothing of rough amorphous metallic surfaces by bombardment with heavy ions in the low keV regime is investigated by a combined experimental-simulational study. Vapor deposited rough amorphous Zr 65 Al 7.5 Cu 27.5 films are the basis for systematic in situ scanning tunneling microscopy measurements on the smoothing reaction due to 3 keV Kr + ion bombardment. The experimental results are directly compared to the predictions of a multiscale simulation approach, which incorporates stochastic rate equations of the Langevin type in combination with previously reported classical molecular dynamics simulations [Phys. Rev. B 75, 224107 (2007)] to model surface smoothing across length and time scales. The combined approach of experiments and simulations clearly corroborates a key role of ion induced viscous flow and ballistic effects in low keV heavy ion induced smoothing of amorphous metallic surfaces at ambient temperatures

  9. In-Situ atomic force microscopic observation of ion beam bombarded plant cell envelopes

    International Nuclear Information System (INIS)

    Sangyuenyongpipat, S.; Yu, L.D.; Brown, I.G.; Seprom, C.; Vilaithong, T.

    2007-01-01

    A program in ion beam bioengineering has been established at Chiang Mai University (CMU), Thailand, and ion beam induced transfer of plasmid DNA molecules into bacterial cells (Escherichia coli) has been demonstrated. However, a good understanding of the fundamental physical processes involved is lacking. In parallel work, onion skin cells have been bombarded with Ar + ions at energy 25 keV and fluence1-2 x 10 15 ions/cm 2 , revealing the formation of microcrater-like structures on the cell wall that could serve as channels for the transfer of large macromolecules into the cell interior. An in-situ atomic force microscope (AFM) system has been designed and installed in the CMU bio-implantation facility as a tool for the observation of these microcraters during ion beam bombardment. Here we describe some of the features of the in-situ AFM and outline some of the related work

  10. Peculiarities of phase transformations in molybdenum-silicon system under ion bombardment

    International Nuclear Information System (INIS)

    Gurskij, L.I.; Zelenin, V.A.; Bobchenok, Yu.L.

    1984-01-01

    The problems of effect of ion bombardment and thermal treatment on the mechanisms of formation of transition layers and structural transformations in the molybdenum-silicon system, where the interface is subjected to ion bombardment through a film of molybdenum, are considered. The method of electron diffraction analysis has been applied to establish that at the molybdenum-silicon interface a transitional region appears during irradiation which has a semiamorphous structure at the doses up to 8x10 14 ion/cm 2 , while at higher doses it transforms into polycrystalline intermediate layer which consists of MoB and the compound close in composition to MoSisub(0.65). Due to thermal treatment for 60873 K a large-grain phase (Mo 3 Si+MoSi 2 ) appears in the transition layer below which a large-grain silicon layer is placed

  11. Investigation of the surface morphology of ion-bombarded biocompatible materials with a SEM and profilograph

    International Nuclear Information System (INIS)

    Kowalski, Z.W.

    1984-01-01

    The surface morphology (topography and roughness) is a very important factor which affects the response of biological tissue to an implant material. The effect of an incident ion beam on surface morphology of various biocompatible materials was studied. All materials were bombarded by Ar + ions at an applied voltage of 7 kV at various incident angles from 0 to 1.4 rad (0 to 80 deg) and at a beam current up to 0.1 mA. The surface topographies of ion-bombarded samples were examined with a Japan Electron Optics Laboratory, model JSM-35, scanning electron microscope. The roughness of the surface was calculated from the shape of a surface profile, which was recorded by a profilograph, the ME 10 (supplied by VEB Carl Zeiss, Jena). (author)

  12. HCN Production via Impact Ejecta Reentry During the Late Heavy Bombardment

    Science.gov (United States)

    Parkos, Devon; Pikus, Aaron; Alexeenko, Alina; Melosh, H. Jay

    2018-04-01

    Major impact events have shaped the Earth as we know it. The Late Heavy Bombardment is of particular interest because it immediately precedes the first evidence of life. The reentry of impact ejecta creates numerous chemical by-products, including biotic precursors such as HCN. This work examines the production of HCN during the Late Heavy Bombardment in more detail. We stochastically simulate the range of impacts on the early Earth and use models developed from existing studies to predict the corresponding ejecta properties. Using multiphase flow methods and finite-rate equilibrium chemistry, we then find the HCN production due to the resulting atmospheric heating. We use Direct Simulation Monte Carlo to develop a correction factor to account for increased yields due to thermochemical nonequilibrium. We then model 1-D atmospheric turbulent diffusion to find the time accurate transport of HCN to lower altitudes and ultimately surface water. Existing works estimate the necessary HCN molarity threshold to promote polymerization that is 0.01 M. For a mixing depth of 100 m, we find that the Late Heavy Bombardment will produce at least one impact event above this threshold with probability 24.1% for an oxidized atmosphere and 56.3% for a partially reduced atmosphere. For a mixing depth of 10 m, the probability is 79.5% for an oxidized atmosphere and 96.9% for a partially reduced atmosphere. Therefore, Late Heavy Bombardment impact ejecta is likely an HCN source sufficient for polymerization in shallow bodies of water, particularly if the atmosphere were in a partially reduced state.

  13. Experiments on secondary ion emission with multicharged keV ion bombardement

    International Nuclear Information System (INIS)

    Della Negra, S.; Depauw, J.; Joret, H.; Le Beyec, Y.; Schweikert, E.A.

    1987-01-01

    An electron cyclotron resonance ion source was used to study the influence of the incident charge state of keV ions on secondary ion emission. The experiments were run with 18 keV Arn+ (1 < n < 11) beams produced by a minimafios source. Various types of targets were bombarded by the ion beam and the sputtered ionized species were identified by time of flight mass spectrometry. The experimental arrangement is detailed and preliminary results are indicated

  14. Phenomenology of the plastic flow of amorphous solids induced by heavy-ion bombardment

    International Nuclear Information System (INIS)

    Klaumuenzer, S.; Benyagoub, A.

    1991-01-01

    Amorphous solids exhibit at temperatures far below the glass transition plastic flow when bombarded with fast heavy ions (kinetic energy ∼1 MeV/u). The dimensions perpendicular to the ion beam grow whereas the sample dimension parallel to the ion beam shrinks. The strain tensor describing phenomenologically these dimensional changes is derived from symmetry considerations and compared with experiment. Particular attention is devoted to angular changes, which have not been discussed in this context so far

  15. Production of the Ne Auger electrons by Ne/sup +/ bombardment of Mg and Al surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ferrante, J; Pepper, S V [National Aeronautics and Space Administration, Cleveland, Ohio (USA). Lewis Research Center

    1976-07-01

    The authors have bombarded Mg and Al surfaces with Ne/sup +/ ions and in this letter present evidence for the production of an inner shell vacancy in the Ne by the asymmetric Ne-Mg and Ne-Al collision. In addition, autoionization states of neutral Ne have been observed. These states are to be distinguished from the more usual case in Auger electron spectroscopy of de-excitation of an ion with a core vacancy.

  16. Removal of foreign atoms from a metal surface bombarded with fast atomic particles

    Energy Technology Data Exchange (ETDEWEB)

    Dolotov, S.K.; Evstigneev, S.A.; Luk' yanov, S.Yu.; Martynenko, Yu.V.; Chicherov, V.M.

    1976-07-01

    A metal surface coated with foreign atoms was irradiated with periodically repeating ion current pulses. The energy of the ions bombarding the target was 20 to 30 keV, and inert gas ions were used. A study of the time dependences of the current of the dislodged foreign atoms showed that the rate of their removal from the target surface is determined by the sputtering coefficient of the substrate metal.

  17. Removal of foreign atoms from a metal surface bombarded with fast atomic particles

    International Nuclear Information System (INIS)

    Dolotov, S.K.; Evstigneev, S.A.; Luk'yanov, S.Yu.; Martynenko, Yu.V.; Chicherov, V.M.

    A metal surface coated with foreign atoms was irradiated with periodically repeating ion current pulses. The energy of the ions bombarding the target was 20 to 30 keV, and inert gas ions were used. A study of the time dependences of the current of the dislodged foreign atoms showed that the rate of their removal from the target surface is determined by the sputtering coefficient of the substrate metal

  18. Titanium oxidation-reduction at low oxygen pressure under electron bombardment

    International Nuclear Information System (INIS)

    Brasca, R.; Passeggi, M.C.G.; Ferron, J.

    2006-01-01

    The effect of the electron bombardment on the first stages of the titanium oxidation process has been studied by means of Auger Electron Spectroscopy. Using Factor Analysis and the valence electron dependence behaviour of the titanium LMV Auger transition, we found that the process is strongly dependent on the oxygen pressure and electron current density. Depending on the irradiation conditions, films of different thickness and Ti oxidized states are obtained

  19. Polymerization of solid C60 under C60 cluster ion bombardment

    Czech Academy of Sciences Publication Activity Database

    Lavrentiev, Vasyl; Vacík, Jiří; Naramoto, H.; Narumi, K.

    2009-01-01

    Roč. 95, - (2009), s. 867-873 ISSN 0947-8396 R&D Projects: GA AV ČR(CZ) KAN400480701; GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z10480505 Keywords : fulleren * cluster * bombardment * polymerization Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.595, year: 2009 http://www.springerlink.com/content/0947-8396

  20. Prism foil from an LCD monitor as a tool for teaching introductory optics

    International Nuclear Information System (INIS)

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and image formation in a nontrivial way and are therefore particularly useful for active learning strategies.