WorldWideScience

Sample records for single ion tracks

  1. A simple and rapid method for high-resolution visualization of single-ion tracks

    Directory of Open Access Journals (Sweden)

    Masaaki Omichi

    2014-11-01

    Full Text Available Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA-N, N’-methylene bisacrylamide (MBAAm blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  2. A simple and rapid method for high-resolution visualization of single-ion tracks

    Energy Technology Data Exchange (ETDEWEB)

    Omichi, Masaaki [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Center for Collaborative Research, Anan National College of Technology, Anan, Tokushima 774-0017 (Japan); Choi, Wookjin; Sakamaki, Daisuke; Seki, Shu, E-mail: seki@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Tsukuda, Satoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Sugimoto, Masaki [Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, Gunma, Gunma 370-1292 (Japan)

    2014-11-15

    Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA)-N, N’-methylene bisacrylamide (MBAAm) blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  3. Swift heavy ion irradiation of CaF2 - from grooves to hillocks in a single ion track

    Science.gov (United States)

    Gruber, Elisabeth; Salou, Pierre; Bergen, Lorenz; El Kharrazi, Mourad; Lattouf, Elie; Grygiel, Clara; Wang, Yuyu; Benyagoub, Abdenacer; Levavasseur, Delphine; Rangama, Jimmy; Lebius, Henning; Ban-d'Etat, Brigitte; Schleberger, Marika; Aumayr, Friedrich

    2016-10-01

    A novel form of ion-tracks, namely nanogrooves and hillocks, are observed on CaF2 after irradiation with xenon and lead ions of about 100 MeV kinetic energy. The irradiation is performed under grazing incidence (0.3°-3°) which forces the track to a region in close vicinity to the surface. Atomic force microscopy imaging of the impact sites with high spatial resolution reveals that the surface track consists in fact of three distinct parts: each swift heavy ion impacting on the CaF2 surface first opens a several 100 nm long groove bordered by a series of nanohillocks on both sides. The end of the groove is marked by a huge single hillock and the further penetration of the swift projectile into deeper layers of the target is accompanied by a single protrusion of several 100 nm in length slowly fading until the track vanishes. By comparing experimental data for various impact angles with results of a simulation, based on a three-dimensional version of the two-temperature-model (TTM), we are able to link the crater and hillock formation to sublimation and melting processes of CaF2 due to the local energy deposition by swift heavy ions.

  4. Controlled ion track etching

    Science.gov (United States)

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

    2006-03-01

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

  5. Diode-like single-ion track membrane prepared by electro-stopping

    International Nuclear Information System (INIS)

    Apel, P.Yu.; Korchev, Yu.E.; Siwy, Z.; Spohr, R.; Yoshida, M.

    2001-01-01

    The preparation of an asymmetric membrane in poly(ethylene terephthalate) (PET) is described, using a combination of chemical and electro-stopping. For this purpose, a single-ion-irradiated PET film is inserted into an electrolytic cell and etched from one side in 9 M sodium hydroxide while bathing the other side in a mixture of 2 M KCl and 2 M HCOOH (1:1 by volume), electrically retracting the OH - ions from the tip of the etch pit during pore break-through. When a preset current has been reached, the etch process is interrupted by replacing the etching solution with acidic 1 M potassium chloride solution. After etching, the current-voltage (I-V) characteristic is determined under symmetric bathing conditions, immersing both sides of the membrane in KCl solutions of identical concentration (0.01-1 M) and pH (3-8). The I-V characteristic is strongly non-linear, comparable to that of an electrical diode. If the polarity during etching is reversed, pushing the OH - ions into the tip of the etch pit, the resulting pores are larger and the degree of asymmetry smaller. The importance of electro-stopping is compared with chemical stopping

  6. Oriented nano-wire formation and selective adhesion on substrates by single ion track reaction in polysilanes

    International Nuclear Information System (INIS)

    Shu Seki; Satoshi Tsukuda, Yoichi Yoshida; Seiichi Tagawa; Masaki Sugimoto; Shigeru Tanaka

    2002-01-01

    1-D nano-sized materials such as carbon nanotubes have attracted much attention as ideal quantum wires for future manufacturing techniques of nano-scaled opto-electronic devices. However it is still difficult to control the sizes, spatial distributions, or positions of nanotubes by conventional synthetic techniques to date. The MeV order heavy ion beams causes ultra-high density energy deposition which can not be realized by any other techniques (lasers, H, etc), and penetrate the polymer target straighforward as long as 1∼100 m depth. the energy deposited area produces non-homogeneous field can be controlled by changing the energy deposition rate of incident ions (LET: linear energy transfer, eV/nm). We found that cross-linking reaction of polysilane derivatives was predominantly caused and gave nano-gel in the chemical core, unlike main chain scission occurring at the outside of the area. high density energy deposition by ion beams causes non-homogeneous crosslinking reaction of polysilane derivatives within a nano-sized cylindrical area along an ion trajectory, and gives -SiC based nano-wires of which sizes (length, thickness) and number densities are completely under control by changing the parameters of incident ion beams and molecular sizes of target polymers. based on the concept pf the single track gelation, the present study demonstrates the formation of cross-linked polysilane nano-wires with the fairly controlled sizes. Recently the techniques of position-selective single ion hitting have been developed for MeV order ion beams, however it is not sufficient to control precisely the positions of the nano-wires on the substrates within sub- m area. in the present study, we report the selective adhesion of anno-wires on Si substrates by the surface treatments before coating, which enables the patterning of planted nano-wires on substrates and/or electrodes as candidates for nano-sized field emissive cathodes or electro-luminescent devices. Some examples of

  7. Elucidating distinct ion channel populations on the surface of hippocampal neurons via single-particle tracking recurrence analysis

    Science.gov (United States)

    Sikora, Grzegorz; Wyłomańska, Agnieszka; Gajda, Janusz; Solé, Laura; Akin, Elizabeth J.; Tamkun, Michael M.; Krapf, Diego

    2017-12-01

    Protein and lipid nanodomains are prevalent on the surface of mammalian cells. In particular, it has been recently recognized that ion channels assemble into surface nanoclusters in the soma of cultured neurons. However, the interactions of these molecules with surface nanodomains display a considerable degree of heterogeneity. Here, we investigate this heterogeneity and develop statistical tools based on the recurrence of individual trajectories to identify subpopulations within ion channels in the neuronal surface. We specifically study the dynamics of the K+ channel Kv1.4 and the Na+ channel Nav1.6 on the surface of cultured hippocampal neurons at the single-molecule level. We find that both these molecules are expressed in two different forms with distinct kinetics with regards to surface interactions, emphasizing the complex proteomic landscape of the neuronal surface. Further, the tools presented in this work provide new methods for the analysis of membrane nanodomains, transient confinement, and identification of populations within single-particle trajectories.

  8. Alternate Double Single Track Lines

    Energy Technology Data Exchange (ETDEWEB)

    Moraga Contreras, P.; Grande Andrade, Z.; Castillo Ron, E.

    2016-07-01

    The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist. (Author)

  9. Single nanoparticle tracking spectroscopic microscope

    Science.gov (United States)

    Yang, Haw [Moraga, CA; Cang, Hu [Berkeley, CA; Xu, Cangshan [Berkeley, CA; Wong, Chung M [San Gabriel, CA

    2011-07-19

    A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

  10. New ways of polymeric ion track characterization

    International Nuclear Information System (INIS)

    Fink, D.; Mueller, M.; Ghosh, S.; Dwivedi, K.K.; Vacik, J.; Hnatowicz, V.; Cervena, J.; Kobayashi, Y.; Hirata, K.

    1999-01-01

    New ways have been applied for characterization of ion tracks in polymers in the last few years, which are essentially related to depth profile determinations of ions, molecules, or positrons penetrating into these tracks. In combination with tomography, the first three-dimensional results have been obtained. Extensive diffusion simulations accompanying the measurements have enabled us to obtain a better understanding of the transport processes going on in ion tracks. This paper gives an overview about the range of new possibilities accessible by these techniques, and summarizes the presently obtained understanding of ion tracks in polymers

  11. Anisotropic plastic deformation by viscous flow in ion tracks

    NARCIS (Netherlands)

    van Dillen, T; Polman, A; Onck, PR; van der Giessen, E

    2005-01-01

    A model describing the origin of ion beam-induced anisotropic plastic deformation is derived and discussed. It is based on a viscoelastic thermal spike model for viscous flow in single ion tracks derived by Trinkaus and Ryazanov. Deviatoric (shear) stresses, brought about by the rapid thermal

  12. Single Cathode Ion Thruster

    Data.gov (United States)

    National Aeronautics and Space Administration — Objective is to design an electrostatic ion thruster that is more efficient, simpler, and lower cost than the current gridded ion thruster. Initial objective is to...

  13. Study of ion tracks by micro-probe ion energy loss spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Vacík, Jiří; Havránek, Vladimír; Hnatowicz, Vladimír; Horák, Pavel; Fink, Dietmar; Apel, P. Yu.

    2014-01-01

    Roč. 332, AUG (2014), s. 308-311 ISSN 0168-583X. [21st International Conference on Ion Beam Analysis (IBA). Seattle, 23.06.2013-28.06.2013] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : ion energy loss spectrometry * single ion track * microprobe * tomography Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.124, year: 2014

  14. Lateral charge transport from heavy-ion tracks in integrated circuit chips

    Science.gov (United States)

    Zoutendyk, J. A.; Schwartz, H. R.; Nevill, L. R.

    1988-01-01

    A 256K DRAM has been used to study the lateral transport of charge (electron-hole pairs) induced by direct ionization from heavy-ion tracks in an IC. The qualitative charge transport has been simulated using a two-dimensional numerical code in cylindrical coordinates. The experimental bit-map data clearly show the manifestation of lateral charge transport in the creation of adjacent multiple-bit errors from a single heavy-ion track. The heavy-ion data further demonstrate the occurrence of multiple-bit errors from single ion tracks with sufficient stopping power. The qualitative numerical simulation results suggest that electric-field-funnel-aided (drift) collection accounts for single error generated by an ion passing through a charge-collecting junction, while multiple errors from a single ion track are due to lateral diffusion of ion-generated charge.

  15. Conducting swift heavy ion track networks

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Kiv, A.; Fuks, D.; Vacík, Jiří; Hnatowicz, Vladimír; Chandra, A.; Saad, A.

    2010-01-01

    Roč. 165, č. 3 (2010), s. 227-244 ISSN 1042-0150 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : ion tracks * negative differential resistance * neural networks Subject RIV: JJ - Other Materials Impact factor: 0.660, year: 2010

  16. Dual color single particle tracking via nanobodies

    International Nuclear Information System (INIS)

    Albrecht, David; Winterflood, Christian M; Ewers, Helge

    2015-01-01

    Single particle tracking is a powerful tool to investigate the function of biological molecules by following their motion in space. However, the simultaneous tracking of two different species of molecules is still difficult to realize without compromising the length or density of trajectories, the localization accuracy or the simplicity of the assay. Here, we demonstrate a simple dual color single particle tracking assay using small, bright, high-affinity labeling via nanobodies of accessible targets with widely available instrumentation. We furthermore apply a ratiometric step-size analysis method to visualize differences in apparent membrane viscosity. (paper)

  17. Environment-sensitive ion-track membranes

    International Nuclear Information System (INIS)

    Yoshida, Masaru

    1996-01-01

    Development of an environment-sensitive porous membrane from ion-track membranes may realize by combining the techniques of ion beam radiation and those of molecular designing and synthesis for intelligent materials. Now, the development of such membrane is progressing with an aim at selecting some specific substances and accurately control its pore size in response to any small environmental stimulus such as temperature change. The authors have been studying the molecular design, synthesis and functional expression of intelligent materials, which are called here as environment-sensitive gels. In this report, the outlines of the apparatus for the production of such porous membrane was described. An organic polymer membrane was irradiated with an ion beam and followed by chemical etching to make ion track pores. Scanning electron microscopic observation for the cross section of the membrane showed that the pore shape varies greatly depending on the ion nuclide used. The characteristics of newly produced porous membranes consisting of CR-30/A-ProDMe and polyethylene-telephtharate were investigated in respect of pore size change responding to temperature. These studies of design, synthesis and functions of such gels would enable to substitute artificial materials for the functions of human sensors. (M.N.). 54 refs

  18. Swift-heavy ion track electronics (SITE)

    International Nuclear Information System (INIS)

    Fink, D.; Chadderton, L.T.; Hoppe, K.; Fahrner, W.R.; Chandra, A.; Kiv, A.

    2007-01-01

    An overview about the state-of-art of the development of a new type of nanoelectronics based on swift-heavy ions is given. Polymeric as well as silicon-based substrates have been used, and both latent and etched ion tracks play a role. Nowadays the interest has shifted from simple scaling-down of capacitors, magnets, transformers, diodes, transistors, etc. towards new types of ion track-based structures hitherto unknown in electronics. These novel structures, denoted by the acronyms 'TEAMS' (tunable electrically anisotropic material on semiconductor) and 'TEMPOS' (tunable electronic material with pores in oxide on semiconductor), may exhibit properties of tunable resistors, capacitors, diodes, sensors and transistors. Their general current/voltage characteristics are outlined. As these structures are often influenced by ambient physical or chemical parameters they also act as sensors. A peculiarity of these structures is the occurrence of negative differential resistances (NDRs) which makes them feasible for applications in tunable flip-flops, amplifiers and oscillators

  19. Swift-heavy ion track electronics (SITE)

    Energy Technology Data Exchange (ETDEWEB)

    Fink, D. [Hahn-Meitner-Institute Berlin, Glienicker Str. 100, D-14109 Berlin (Germany)]. E-mail: fink@hmi.de; Chadderton, L.T. [Institute of Advanced Studies, ANU Canberra, G.P.O. Box 4, ACT (Australia); Hoppe, K. [South Westfalia University of Applied Sciences, Hagen (Germany); Fahrner, W.R. [Chair of Electronic Devices, Inst. of Electrotechnique, Fernuniversitaet, Hagen (Germany); Chandra, A. [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Kiv, A. [Ben Gurion University of the Negev, Israel, P.O. Box 653, Beer-Sheva, 84105 (Israel)

    2007-08-15

    An overview about the state-of-art of the development of a new type of nanoelectronics based on swift-heavy ions is given. Polymeric as well as silicon-based substrates have been used, and both latent and etched ion tracks play a role. Nowadays the interest has shifted from simple scaling-down of capacitors, magnets, transformers, diodes, transistors, etc. towards new types of ion track-based structures hitherto unknown in electronics. These novel structures, denoted by the acronyms 'TEAMS' (tunable electrically anisotropic material on semiconductor) and 'TEMPOS' (tunable electronic material with pores in oxide on semiconductor), may exhibit properties of tunable resistors, capacitors, diodes, sensors and transistors. Their general current/voltage characteristics are outlined. As these structures are often influenced by ambient physical or chemical parameters they also act as sensors. A peculiarity of these structures is the occurrence of negative differential resistances (NDRs) which makes them feasible for applications in tunable flip-flops, amplifiers and oscillators.

  20. Symplectic Tracking of Multi-Isotopic Heavy-Ion Beams in SixTrack

    CERN Document Server

    Hermes, Pascal; De Maria, Riccardo

    2016-01-01

    The software SixTrack provides symplectic proton tracking over a large number of turns. The code is used for the tracking of beam halo particles and the simulation of their interaction with the collimators to study the efficiency of the LHC collimation system. Tracking simulations for heavy-ion beams require taking into account the mass to charge ratio of each particle because heavy ions can be subject to fragmentation at their passage through the collimators. In this paper we present the derivation of a Hamiltonian for multi-isotopic heavy-ion beams and symplectic tracking maps derived from it. The resulting tracking maps were implemented in the tracking software SixTrack. With this modification, SixTrack can be used to natively track heavy-ion beams of multiple isotopes through a magnetic accelerator lattice.

  1. Single track coincidence measurements of fluorescent and plastic nuclear track detectors in therapeutic carbon beams

    International Nuclear Information System (INIS)

    Osinga, J-M; Jäkel, O; Ambrožová, I; Brabcová, K Pachnerová; Davídková, M; Akselrod, M S; Greilich, S

    2014-01-01

    In this paper we present a method for single track coincidence measurements using two different track detector materials. We employed plastic and fluorescent nuclear track detectors (PNTDs and FNTDs) in the entrance channel of a monoenergetic carbon ion beam covering the therapeutic energy range from 80 to 425 MeV/u. About 99% of all primary particle tracks detected by both detectors were successfully matched, while 1% of the particles were only detected by the FNTDs because of their superior spatial resolution. We conclude that both PNTDs and FNTDs are suitable for clinical carbon beam dosimetry with a detection efficiency of at least 98.82% and 99.83% respectively, if irradiations are performed with low fluence in the entrance channel of the ion beam. The investigated method can be adapted to other nuclear track detectors and offers the possibility to characterize new track detector materials against well-known detectors. Further, by combining two detectors with a restricted working range in the presented way a hybrid-detector system can be created with an extended and optimized working range

  2. Tracking Lithium Ions via Widefield Fluorescence Microscopy for Battery Diagnostics.

    Science.gov (United States)

    Padilla, Nicolas A; Rea, Morgan T; Foy, Michael; Upadhyay, Sunil P; Desrochers, Kyle A; Derus, Tyler; Knapper, Kassandra A; Hunter, Nathanael H; Wood, Sharla; Hinton, Daniel A; Cavell, Andrew C; Masias, Alvaro G; Goldsmith, Randall H

    2017-07-28

    Direct tracking of lithium ions with time and spatial resolution can provide an important diagnostic tool for understanding mechanisms in lithium ion batteries. A fluorescent indicator of lithium ions, 2-(2-hydroxyphenyl)naphthoxazole, was synthesized and used for real-time tracking of lithium ions via widefield fluorescence microscopy. The fluorophore can be excited with visible light and was shown to enable quantitative determination of the lithium ion diffusion constant in a microfluidic model system for a plasticized polymer electrolyte lithium battery. The use of widefield fluorescence microscopy for in situ tracking of lithium ions in batteries is discussed.

  3. Single ion hit detection set-up for the Zagreb ion microprobe

    Science.gov (United States)

    Smith, R. W.; Karlušić, M.; Jakšić, M.

    2012-04-01

    Irradiation of materials by heavy ions accelerated in MV tandem accelerators may lead to the production of latent ion tracks in many insulators and semiconductors. If irradiation is performed in a high resolution microprobe facility, ion tracks can be ordered by submicrometer positioning precision. However, full control of the ion track positioning can only be achieved by a reliable ion hit detection system that should provide a trigger signal irrespectively of the type and thickness of the material being irradiated. The most useful process that can be utilised for this purpose is emission of secondary electrons from the sample surface that follows the ion impact. The status report of the set-up presented here is based on the use of a channel electron multiplier (CEM) detector mounted on an interchangable sample holder that is inserted into the chamber in a close geometry along with the sample to be irradiated. The set-up has been tested at the Zagreb ion microprobe for different ions and energies, as well as different geometrical arrangements. For energies of heavy ions below 1 MeV/amu, results show that efficient (100%) control of ion impact can be achieved only for ions heavier than silicon. The successful use of the set-up is demonstrated by production of ordered single ion tracks in a polycarbonate film and by monitoring fluence during ion microbeam patterning of Foturan glass.

  4. Tracks induced by swift heavy ions in semiconductors

    International Nuclear Information System (INIS)

    Szenes, G.; Horvath, Z.E.; Pecz, B.; Toth, L.; Paszti, F.

    2002-01-01

    InSb, GaSb, InP, InAs, and GaAs single crystals were irradiated with Pb ions in the range of 385-2170 MeV. The samples were studied by transmission and high-resolution electron microscopy and Rutherford backscattering in channeling geometry. The energetic ions induced isolated tracks in all crystals but GaAs. The thermal spike analysis revealed that the variation of the damage cross section with the ion energy is considerably weaker than in insulators. The widths of the thermal spike a(0) was estimated. The analysis was extended to recent C 60 experiments on Ge and Si. A quantitative relation was found between a(0) and the gap energy E g : a(0) is reduced with increasing E g , and its lowest value is close to that found in insulators

  5. An automated single ion hit at JAERI heavy ion microbeam to observe individual radiation damage

    International Nuclear Information System (INIS)

    Kamiya, Tomihiro; Sakai, Takuro; Naitoh, Yutaka; Hamano, Tsuyoshi; Hirao, Toshio

    1999-01-01

    Microbeam scanning and a single ion hit technique have been combined to establish an automated beam positioning and single ion hit system at the JAERI Takasaki heavy ion microbeam system. Single ion irradiation on preset points of a sample in various patterns can be performed automatically in a short period. The reliability of the system was demonstrated using CR-39 nuclear track detectors. Single ion hit patterns were achieved with a positioning accuracy of 2 μm or less. In measurement of single event transient current using this system, the reduction of the pulse height by accumulation of radiation damages was observed by single ion injection to the same local areas. This technique showed a possibility to get some quantitative information about the lateral displacement of an individual radiation effect in silicon PIN photodiodes. This paper will give details of the irradiation system and present results from several experiments

  6. Visualization of complex DNA damage along accelerated ions tracks

    Science.gov (United States)

    Kulikova, Elena; Boreyko, Alla; Bulanova, Tatiana; Ježková, Lucie; Zadneprianetc, Mariia; Smirnova, Elena

    2018-04-01

    The most deleterious DNA lesions induced by ionizing radiation are clustered DNA double-strand breaks (DSB). Clustered or complex DNA damage is a combination of a few simple lesions (single-strand breaks, base damage etc.) within one or two DNA helix turns. It is known that yield of complex DNA lesions increases with increasing linear energy transfer (LET) of radiation. For investigation of the induction and repair of complex DNA lesions, human fibroblasts were irradiated with high-LET 15N ions (LET = 183.3 keV/μm, E = 13MeV/n) and low-LET 60Co γ-rays (LET ≈ 0.3 keV/μm) radiation. DNA DSBs (γH2AX and 53BP1) and base damage (OGG1) markers were visualized by immunofluorecence staining and high-resolution microscopy. The obtained results showed slower repair kinetics of induced DSBs in cells irradiated with accelerated ions compared to 60Co γ-rays, indicating induction of more complex DNA damage. Confirming previous assumptions, detailed 3D analysis of γH2AX/53BP1 foci in 15N ions tracks revealed more complicated structure of the foci in contrast to γ-rays. It was shown that proteins 53BP1 and OGG1 involved in repair of DNA DSBs and modified bases, respectively, were colocalized in tracks of 15N ions and thus represented clustered DNA DSBs.

  7. Composition dependent thermal annealing behaviour of ion tracks in apatite

    Energy Technology Data Exchange (ETDEWEB)

    Nadzri, A., E-mail: allina.nadzri@anu.edu.au [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia); Schauries, D.; Mota-Santiago, P.; Muradoglu, S. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64287 Darmstadt (Germany); Gleadow, A.J.W. [School of Earth Science, University of Melbourne, Melbourne, VIC 3010 (Australia); Hawley, A. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Kluth, P. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia)

    2016-07-15

    Natural apatite samples with different F/Cl content from a variety of geological locations (Durango, Mexico; Mud Tank, Australia; and Snarum, Norway) were irradiated with swift heavy ions to simulate fission tracks. The annealing kinetics of the resulting ion tracks was investigated using synchrotron-based small-angle X-ray scattering (SAXS) combined with ex situ annealing. The activation energies for track recrystallization were extracted and consistent with previous studies using track-etching, tracks in the chlorine-rich Snarum apatite are more resistant to annealing than in the other compositions.

  8. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  9. The shape of ion tracks in natural apatite

    Science.gov (United States)

    Schauries, D.; Afra, B.; Bierschenk, T.; Lang, M.; Rodriguez, M. D.; Trautmann, C.; Li, W.; Ewing, R. C.; Kluth, P.

    2014-05-01

    Small angle X-ray scattering measurements were performed on natural apatite of different thickness irradiated with 2.2 GeV Au swift heavy ions. The evolution of the track radius along the full ion track length was estimated by considering the electronic energy loss and the velocity of the ions. The shape of the track is nearly cylindrical, slightly widening with a maximum diameter approximately 30 μm before the ions come to rest, followed by a rapid narrowing towards the end within a cigar-like contour. Measurements of average ion track radii in samples of different thicknesses, i.e. containing different sections of the tracks are in good agreement with the shape estimate.

  10. The shape of ion tracks in natural apatite

    International Nuclear Information System (INIS)

    Schauries, D.; Afra, B.; Bierschenk, T.; Lang, M.; Rodriguez, M.D.; Trautmann, C.; Li, W.; Ewing, R.C.; Kluth, P.

    2014-01-01

    Small angle X-ray scattering measurements were performed on natural apatite of different thickness irradiated with 2.2 GeV Au swift heavy ions. The evolution of the track radius along the full ion track length was estimated by considering the electronic energy loss and the velocity of the ions. The shape of the track is nearly cylindrical, slightly widening with a maximum diameter approximately 30 μm before the ions come to rest, followed by a rapid narrowing towards the end within a cigar-like contour. Measurements of average ion track radii in samples of different thicknesses, i.e. containing different sections of the tracks are in good agreement with the shape estimate

  11. Deposition of molecular probes in heavy ion tracks

    CERN Document Server

    Esser, M

    1999-01-01

    By using polarized fluorescence techniques the physical properties of heavy ion tracks such as the dielectric number, molecular alignment and track radius can be traced by molecular fluorescence probes. Foils of poly(ethylene terephthalate) (PET) were used as a matrix for the ion tracks wherein fluorescence probes such as aminostyryl-derivatives can be incorporated using a suitable solvent, e.g. N,N'-dimethylformamide (DMF) as transport medium. The high sensitivity of fluorescence methods allowed the comparison of the probe properties in ion tracks with the virgin material. From the fluorescence Stokes shift the dielectric constants could be calculated, describing the dielectric surroundings of the molecular probes. The lower dielectric constant in the tracks gives clear evidence that there is no higher accommodation of the highly polar solvent DMF in the tracks compared with the virgin material. Otherwise the dielectric constant in the tracks should be higher than in the virgin material. The orientation of t...

  12. Creation of nanoscale objects by swift heavy ion track manipulations

    International Nuclear Information System (INIS)

    Fink, D.; Petrov, A.; Stolterfoht, N.

    2003-01-01

    In this work we give an overview of the possibilities to create new objects with nanoscale dimensions with ion tracks, for future applications. This can be realized in two ways: by manipulation of latent swift heavy ion (SHI) tracks, or by embedding specific structures within etched SHI tracks. In the first case one can make use of irradiation effects such as phase transitions and chemical or structural changes along the tracks. In the latter case, one can fill etched SHI tracks with metals, semiconductors, insulating and conducting polymers, fullerite, or colloides. Wires and tubules with outer diameters, between about 50 nm and 5 μm and lengths of up to about 100 μm can be obtained. The most important production techniques are galvanic and chemical depositions. Ion Transmission Spectrometry has turned out to be an especially useful tool for the characterisation of the produced objects. Present studies aim at the construction of condensers, magnets, diodes, and sensors in etched tracks. An obstacle for the practical realization of smallest-size polymeric ion track devices is the statistical distribution of the ion tracks on the target areas, which yields some pixels without any track, and other pixels even with overlapping tracks on a given sample. In a first test experiment we demonstrate that one can, in principle, overcome that problem by taking self-ordered porous foils as masks for subsequent high-fluence SHI irradiation. (author)

  13. Crater formation by single ions, cluster ions and ion "showers"

    CERN Document Server

    Djurabekova, Flyura; Timko, Helga; Nordlund, Kai; Calatroni, Sergio; Taborelli, Mauro; Wuensch, Walter

    2011-01-01

    The various craters formed by giant objects, macroscopic collisions and nanoscale impacts exhibit an intriguing resemblance in shapes. At the same time, the arc plasma built up in the presence of sufficiently high electric fields at close look causes very similar damage on the surfaces. Although the plasma–wall interaction is far from a single heavy ion impact over dense metal surfaces or the one of a cluster ion, the craters seen on metal surfaces after a plasma discharge make it possible to link this event to the known mechanisms of the crater formations. During the plasma discharge in a high electric field the surface is subject to high fluxes (~1025 cm-2s-1) of ions with roughly equal energies typically of the order of a few keV. To simulate such a process it is possible to use a cloud of ions of the same energy. In the present work we follow the effect of such a flux of ions impinging the surface in the ‘‘shower’’ manner, to find the transition between the different mechanisms of crater formati...

  14. Single particle tracking and single molecule energy transfer

    CERN Document Server

    Bräuchle, Christoph; Michaelis, Jens

    2009-01-01

    Closing a gap in the literature, this handbook gathers all the information on single particle tracking and single molecule energy transfer. It covers all aspects of this hot and modern topic, from detecting virus entry to membrane diffusion, and from protein folding using spFRET to coupled dye systems, as well recent achievements in the field. Throughout, the first-class editors and top international authors present content of the highest quality, making this a must-have for physical chemists, spectroscopists, molecular physicists and biochemists.

  15. Morphology and annealing kinetics of ion tracks in minerals

    Directory of Open Access Journals (Sweden)

    Ewing R. C.

    2012-10-01

    Full Text Available We have studied the morphology and annealing kinetics of ion tracks in Durango apatite using synchrotron small angle X-ray scattering. The non-destructive, artefact-free technique enables us to determine the track radii with a resolution of fractions of a nanometre. The tracks were generated using different heavy ions with energies between 185 MeV and 2.6 GeV. The track morphology is consistent with the formation of long cylindrical amorphous tracks. The annealing kinetics, measured by SAXS in combination with ex situ and in situ annealing experiments, suggests structural relaxation followed by recrystallisation of the damaged material. The measurement methodology shown here provides a new means for in-depth studies of ion-track formation in minerals under a wide variety of geological conditions.

  16. Structure of heavy-ion tracks in zircon

    International Nuclear Information System (INIS)

    Braunshausen, G.; Bursill, L.A.; Vetter, J.; Spohr, R.

    1990-01-01

    Gem quality zirconas (ZrSiO 4 ) were irradiated with 14MeV/u Pb ions. Observations of heavy-ion tracks confirmed that fission or heavy-ion irradiation damage is confined to a 50-100 Aangstroem core region, which has undergone a crystalline-glass phase transition. 3 refs., 3 figs

  17. Secondary particle tracks generated by ion beam irradiation

    Science.gov (United States)

    García, Gustavo

    2015-05-01

    The Low Energy Particle Track Simulation (LEPTS) procedure is a powerful complementary tool to include the effect of low energy electrons and positrons in medical applications of radiation. In particular, for ion-beam cancer treatments provides a detailed description of the role of the secondary electrons abundantly generated around the Bragg peak as well as the possibility of using transmuted positron emitters (C11, O15) as a complement for ion-beam dosimetry. In this study we present interaction probability data derived from IAM-SCAR corrective factors for liquid environments. Using these data, single electron and positron tracks in liquid water and pyrimidine have been simulated providing information about energy deposition as well as the number and type of interactions taking place in any selected ``nanovolume'' of the irradiated area. In collaboration with Francisco Blanco, Universidad Complutense de Madrid; Antonio Mu noz, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas and Diogo Almeida, Filipe Ferreira da Silva, Paulo Lim ao-Vieira, Universidade Nova de Lisboa. Supported by the Spanish and Portuguese governments.

  18. On the structure of etched ion tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Hnatowicz, Vladimír; Vacík, Jiří; Apel, P. Yu.

    2016-01-01

    Roč. 121, APR (2016), s. 106-109 ISSN 0969-806X R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : polymers * ion tracks * track etching Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.315, year: 2016

  19. The UIC 406 capacity method used on single track sections

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.; Jacobsen, Erik M.

    2007-01-01

    This paper describes the relatively new UIC 406 capacity method which is an easy and effective way of calculating capacity consumption on railway lines. However, it is possible to expound the method in different ways which can lead to different capacity consumptions. This paper describes the UIC...... 406 method for single track lines and how it is expounded in Denmark. Many capacity analyses using the UIC 406 capacity method for double track lines have been carried out and presented internationally but only few capacity analyses using the UIC 406 capacity method on single track lines have been...... presented. Therefore, the differences between capacity analysis for double track lines and single track lines are discussed in the beginning of this paper. Many of the principles of the UIC 406 capacity analyses on double track lines can be used on single track lines – at least when more than one train...

  20. Thermal spike analysis of highly charged ion tracks

    International Nuclear Information System (INIS)

    Karlušić, M.; Jakšić, M.

    2012-01-01

    The irradiation of material using swift heavy ion or highly charged ion causes excitation of the electron subsystem at nanometer scale along the ion trajectory. According to the thermal spike model, energy deposited into the electron subsystem leads to temperature increase due to electron–phonon coupling. If ion-induced excitation is sufficiently intensive, then melting of the material can occur, and permanent damage (i.e., ion track) can be formed upon rapid cooling. We present an extension of the analytical thermal spike model of Szenes for the analysis of surface ion track produced after the impact of highly charged ion. By applying the model to existing experimental data, more than 60% of the potential energy of the highly charged ion was shown to be retained in the material during the impact and transformed into the energy of the thermal spike. This value is much higher than 20–40% of the transferred energy into the thermal spike by swift heavy ion. Thresholds for formation of highly charged ion track in different materials show uniform behavior depending only on few material parameters.

  1. Design of tracking photovoltaic systems with a single vertical axis

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, E. [Ciudad Universitaria, Madrid (Spain). Instituto de Energeia Solar; Perez, M. [Pol Industrial La Nava, Naavarrsa (Spain). Alternativas Energeticas Solares; Ezpeleta, A. [Energia Hidroelectrica Navarra, Pamplona (Spain); Acedo, J. [Ingeteam SA, Pamplona (Spain)

    2002-07-01

    Solar tracking is used in large grid-connected photovoltaic plants to maximise solar radiation collection and, hence, to reduce the cost of delivered electricity. In particular, single vertical axis tracking, also called azimuth tracking, allows for energy gains up to 40%, compared with optimally tilted fully static arrays. This paper examines the theoretical aspects associated with the design of azimuth tracking, taking into account shadowing between different trackers and back-tracking features. Then, the practical design of the trackers installed at the 1.4 MW Tudela PV plant is presented and discussed. Finally, this tracking alternative is compared with the more conventional fully stationary approach. (author)

  2. Preparation of fluoropolymer-based ion-track membranes. Structure of latent tracks and pretreatment effect

    International Nuclear Information System (INIS)

    Yamaki, Tetsuya; Nuryanthi, Nuryanthi; Koshikawa, Hiroshi; Sawada, Shinichi; Hakoda, Teruyuki; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari

    2012-01-01

    High-energy heavy-ion induced damage, called latent tracks m organic polymers can sometimes be etched out chemically to give submicro- and nano-sized pores. Our focus is placed on ion-track membranes of poly(vinylidene fluoride) (PVDF), a type of fluoropolymer, which were previously considered as a matrix of polymer electrolyte fuel-cell membranes. There have been no optimized methods of preparing the PVDF-based ion-track membranes. We thus examined chemical structures of the defects created in the track, and accordingly, presented a pretreatment technique for achieving more efficient track etching. A 25 μm-thick PVDF film was bombarded with 1.1 GeV 238 U or 450 MeV 129 Xe ions. In the multi-purpose chamber, degradation processes were monitored in-situ by FT-IR spectroscopy and residual gas analysis as a function of the fluence up to 6.0 x 10 11 ions/cm 2 . The films irradiated at 8 ions/cm 2 were etched in a 9 M KOH aqueous solution at 80degC. We also performed the conductometric etching, which allows monitoring of pore evolution versus etching time by recording the electrical conductance through the membrane. At fluences above 1 x 10 10 ions/cm 2 , the film showed two new absorption bands identified as double-bond stretching vibrations of in-chain unsaturations -CH=CF- and fluorinated vinyl groups -CF 2 CH=CF 2 . These defects would result from the evolution of HF. The knowledge of the solubility in a permanganate alkaline solution and our preliminary experiment suggested the importance of oxidized tracks for the easy introduction of the etching agent. We finally found that the pretreatment with ozone could oxidize the double bonds in the tracks, thereby vigorously promoting track etching before breakthrough. (author)

  3. Temperature annealing of tracks induced by ion irradiation of graphite

    International Nuclear Information System (INIS)

    Liu, J.; Yao, H.J.; Sun, Y.M.; Duan, J.L.; Hou, M.D.; Mo, D.; Wang, Z.G.; Jin, Y.F.; Abe, H.; Li, Z.C.; Sekimura, N.

    2006-01-01

    Highly oriented pyrolytic graphite (HOPG) samples were irradiated by Xe ions of initial kinetic energy of 3 MeV/u. The irradiations were performed at temperatures of 500 and 800 K. Scanning tunneling microscopy (STM) images show that the tracks occasionally have elongated structures under high-temperature irradiation. The track creation yield at 800 K is by three orders of magnitude smaller compared to that obtained during room-temperature irradiation. STM and Raman spectra show that amorphization occurs in graphite samples irradiated at 500 K to higher fluences, but not at 800 K. The obtained experimental results clearly reveal that the irradiation under high temperature causes track annealing

  4. Etched ion track polymer membranes for sustained drug delivery

    International Nuclear Information System (INIS)

    Rao, Vijayalakshmi; Amar, J.V.; Avasthi, D.K.; Narayana Charyulu, R.

    2003-01-01

    The method of track etching has been successfully used for the production of polymer membranes with capillary pores. In the present paper, micropore membranes have been prepared by swift heavy ion irradiation of polycarbonate (PC). PC films were irradiated with ions of gold, silicon and oxygen of varying energies and fluence. The ion tracks thus obtained were etched chemically for various time intervals to get pores and these etched films were used as membranes for the drug release. Ciprofloxacine hydrochloride was used as model drug for the release studies. The drug content was estimated spectrophotometrically. Pore size and thus the drug release is dependent on the etching conditions, ions used, their energy and fluence. Sustained drug release has been observed in these membranes. The films can be selected for practical utilization by optimizing the irradiation and etching conditions. These films can be used as transdermal patches after medical treatment

  5. Dose distribution around ion track in tissue equivalent material

    International Nuclear Information System (INIS)

    Zhang Wenzhong; Guo Yong; Luo Yisheng

    2007-01-01

    Objective: To study the energy deposition micro-specialty of ions in body-tissue or tissue equivalent material (TEM). Methods: The water vapor was determined as the tissue equivalent material, based on the analysis to the body-tissue, and Monte Carlo method was used to simulate the behavior of proton in the tissue equivalent material. Some features of the energy deposition micro-specialty of ion in tissue equivalent material were obtained through the analysis to the data from calculation. Results: The ion will give the energy by the way of excitation and ionization in material, then the secondary electrons will be generated in the progress of ionization, these electron will finished ions energy deposition progress. When ions deposited their energy, large amount energy will be in the core of tracks, and secondary electrons will devote its' energy around ion track, the ion dose distribution is then formed in TEM. Conclusions: To know biological effects of radiation , the research to dose distribution of ions is of importance(significance). (authors)

  6. Ion track etching revisited: I. Correlations between track parameters in aged polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Vacík, Jiří; Hnatowicz, Vladimír; Kiv, A.; Alfonta, L.

    2018-01-01

    Roč. 420, č. 4 (2018), s. 57-68 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : ion track * polymer * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders OBOR OECD: Nuclear physics Impact factor: 1.109, year: 2016

  7. Ion track etching revisited: II. Electronic properties of aged tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Hernandez, G. M.; Cruz, S. A.; Garcia-Arellano, H.; Vacík, Jiří; Hnatowicz, Vladimír; Kiv, A.; Alfonta, L.

    2018-01-01

    Roč. 173, 1-2 (2018), s. 148-164 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : polymers * ion tracks * etching * conductometry * rectification * phase shift Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 0.443, year: 2016

  8. Impact of time and space evolution of ion tracks in nonvolatile memory cells approaching nanoscale

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Murat, M.; Barak, J.; Akkerman, A.; Harboe-Sorensen, R.; Virtanen, A.; Visconti, A.; Bonanomi, M.

    2010-01-01

    Swift heavy ions impacting on matter lose energy through the creation of dense tracks of charges. The study of the space and time evolution of energy exchange allows understanding the single event effects behavior in advanced microelectronic devices. In particular, the shrinking of minimum feature size of most advanced memory devices makes them very interesting test vehicles to study these effects since the device and the track dimensions are comparable; hence, measured effects are directly correlated with the time and space evolution of the energy release. In this work we are studying the time and space evolution of ion tracks by using advanced non volatile memories and Monte Carlo simulations. Experimental results are very well explained by the theoretical calculations.

  9. Recent Developments in the Code RITRACKS (Relativistic Ion Tracks)

    Science.gov (United States)

    Plante, Ianik; Ponomarev, Artem L.; Blattnig, Steve R.

    2018-01-01

    The code RITRACKS (Relativistic Ion Tracks) was developed to simulate detailed stochastic radiation track structures of ions of different types and energies. Many new capabilities were added to the code during the recent years. Several options were added to specify the times at which the tracks appear in the irradiated volume, allowing the simulation of dose-rate effects. The code has been used to simulate energy deposition in several targets: spherical, ellipsoidal and cylindrical. More recently, density changes as well as a spherical shell were implemented for spherical targets, in order to simulate energy deposition in walled tissue equivalent proportional counters. RITRACKS is used as a part of the new program BDSTracks (Biological Damage by Stochastic Tracks) to simulate several types of chromosome aberrations in various irradiation conditions. The simulation of damage to various DNA structures (linear and chromatin fiber) by direct and indirect effects has been improved and is ongoing. Many improvements were also made to the graphic user interface (GUI), including the addition of several labels allowing changes of units. A new GUI has been added to display the electron ejection vectors. The parallel calculation capabilities, notably the pre- and post-simulation processing on Windows and Linux machines have been reviewed to make them more portable between different systems. The calculation part is currently maintained in an Atlassian Stash® repository for code tracking and possibly future collaboration.

  10. Ion track etching revisited: II. Electronic properties of aged tracks in polymers

    Science.gov (United States)

    Fink, D.; Muñoz Hernández, G.; Cruz, S. A.; Garcia-Arellano, H.; Vacik, J.; Hnatowicz, V.; Kiv, A.; Alfonta, L.

    2018-02-01

    We compile here electronic ion track etching effects, such as capacitive-type currents, current spike emission, phase shift, rectification and background currents that eventually emerge upon application of sinusoidal alternating voltages across thin, aged swift heavy ion-irradiated polymer foils during etching. Both capacitive-type currents and current spike emission occur as long as obstacles still prevent a smooth continuous charge carrier passage across the foils. In the case of sufficiently high applied electric fields, these obstacles are overcome by spike emission. These effects vanish upon etchant breakthrough. Subsequent transmitted currents are usually of Ohmic type, but shortly after breakthrough (during the track' core etching) often still exhibit deviations such as strong positive phase shifts. They stem from very slow charge carrier mobility across the etched ion tracks due to retarding trapping/detrapping processes. Upon etching the track's penumbra, one occasionally observes a split-up into two transmitted current components, one with positive and another one with negative phase shifts. Usually, these phase shifts vanish when bulk etching starts. Current rectification upon track etching is a very frequent phenomenon. Rectification uses to inverse when core etching ends and penumbra etching begins. When the latter ends, rectification largely vanishes. Occasionally, some residual rectification remains which we attribute to the aged polymeric bulk itself. Last not least, we still consider background currents which often emerge transiently during track etching. We could assign them clearly to differences in the electrochemical potential of the liquids on both sides of the etched polymer foils. Transient relaxation effects during the track etching cause their eventually chaotic behaviour.

  11. Ion track etching revisited: I. Correlations between track parameters in aged polymers

    Science.gov (United States)

    Fink, D.; Muñoz H., G.; García A., H.; Vacik, J.; Hnatowicz, V.; Kiv, A.; Alfonta, L.

    2018-04-01

    Some yet poorly understood problems of etching of pristine and swift heavy ion track-irradiated aged polymers were treated, by applying conductometry across the irradiated foils during etching. The onset times of etchant penetration across pristine foils, and the onset times of the different etched track regimes in irradiated foils were determined for polymers of various proveniences, fluences and ages, as well as their corresponding etching speeds. From the results, correlations of the parameters with each other were deduced. The normalization of these parameters enables one to compare irradiated polymer foils of different origin and treatment with one another. In a number of cases, also polymeric gel formation and swelling occur which influence the track etching behaviour. The polymer degradation during aging influences the track etching parameters, which differ from each other on both sides of the foils. With increasing sample age, these differences increase.

  12. Single-Particle Tracking of Human Lipoproteins.

    Science.gov (United States)

    de Messieres, Michel; Ng, Abby; Duarte, Cornelio J; Remaley, Alan T; Lee, Jennifer C

    2016-01-05

    Lipoproteins, such as high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low density lipoprotein (VLDL), play a critical role in heart disease. Lipoproteins vary in size and shape as well as in their apolipoprotein content. Here, we developed a new experimental framework to study freely diffusing lipoproteins from human blood, allowing analysis of even the smallest HDL with a radius of 5 nm. In an easily constructed confinement chamber, individual HDL, LDL, and VLDL particles labeled with three distinct fluorophores were simultaneously tracked by wide-field fluorescence microscopy and their sizes were determined by their motion. This technique enables studies of individual lipoproteins in solution and allows characterization of the heterogeneous properties of lipoproteins which affect their biological function but are difficult to discern in bulk studies.

  13. Production of multi-, oligo- and single-pore membranes using a continuous ion beam

    Czech Academy of Sciences Publication Activity Database

    Apel, P. Yu.; Ivanov, O.; Lizunov, N. E.; Mamonova, T. I.; Nechaev, A. N.; Olejniczak, K.; Vacík, Jiří; Dmitriev, S. N.

    2015-01-01

    Roč. 365, DEC (2015), s. 641-645 ISSN 0168-583X R&D Projects: GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : ion beam * irradiation * ion track * etching * single nanopore Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.389, year: 2015

  14. Investigations of heavy ion tracks in polyethylene naphthalate films

    CERN Document Server

    Starosta, W; Sartowska, B; Buczkowski, M

    1999-01-01

    The heavy ion beam (with fluence 3x10 sup 8 ion/cm sup 2) from a cyclotron has been used for irradiation of thin polyethylene naphthalate (PEN) films. Latent tracks in these polymeric films have been sensitized by UV radiation and then chemically etched in NaOH solution. The etching process parameters have been controlled by the electroconductivity method. After etching, parameters of samples have been examined by SEM and bubble point methods (Coulter[reg] Porometer II instrument). Results have shown good quality of PEN track membranes with pore sizes in the range: 0.1 - 0.5 mu m. The described procedure is known for thin polyethylene terephthalate (PET) films. Taking into consideration that PEN films have got better mechanical, thermal, gas barrier as well as better chemical resistance properties in comparison with PET films, the possibility of application of such membranes is much wider.

  15. Ion track membranes providing heat pipe surfaces with capillary structures

    International Nuclear Information System (INIS)

    Akapiev, G.N.; Dmitriev, S.N.; Erler, B.; Shirkova, V.V.; Schulz, A.; Pietsch, H.

    2003-01-01

    The microgalvanic method for metal filling of etched ion tracks in organic foils is of particular interest for the fabrication of microsized structures. Microstructures like copper whiskers with a high aspect ratio produced in ion track membranes are suitable for the generation of high-performance heat transfer surfaces. A surface with good heat transfer characteristics is defined as a surface on which a small temperature difference causes a large heat transfer from the surface material to the liquid. It is well-known that a porous surface layer transfers to an evaporating liquid a given quantity of heat at a smaller temperature difference than does a usual smooth surface. Copper whiskers with high aspect ratio and a density 10 5 per cm 2 form such a porous structure, which produces strong capillary forces and therefore a maximum of heat transfer coefficients

  16. Model of wet chemical etching of swift heavy ions tracks

    Science.gov (United States)

    Gorbunov, S. A.; Malakhov, A. I.; Rymzhanov, R. A.; Volkov, A. E.

    2017-10-01

    A model of wet chemical etching of tracks of swift heavy ions (SHI) decelerated in solids in the electronic stopping regime is presented. This model takes into account both possible etching modes: etching controlled by diffusion of etchant molecules to the etching front, and etching controlled by the rate of a reaction of an etchant with a material. Olivine ((Mg0.88Fe0.12)2SiO4) crystals were chosen as a system for modeling. Two mechanisms of chemical activation of olivine around the SHI trajectory are considered. The first mechanism is activation stimulated by structural transformations in a nanometric track core, while the second one results from neutralization of metallic atoms by generated electrons spreading over micrometric distances. Monte-Carlo simulations (TREKIS code) form the basis for the description of excitations of the electronic subsystem and the lattice of olivine in an SHI track at times up to 100 fs after the projectile passage. Molecular dynamics supplies the initial conditions for modeling of lattice relaxation for longer times. These simulations enable us to estimate the effects of the chemical activation of olivine governed by both mechanisms. The developed model was applied to describe chemical activation and the etching kinetics of tracks of Au 2.1 GeV ions in olivine. The estimated lengthwise etching rate (38 µm · h-1) is in reasonable agreement with that detected in the experiments (24 µm · h-1).

  17. Improved single ion cyclotron resonance mass spectroscopy

    International Nuclear Information System (INIS)

    Boyce, K.R.

    1993-01-01

    The author has improved the state of the art for precision mass spectroscopy of a mass doublet to below one part in 10 10 . By alternately loading single ions into a Penning trap, the author has determined the mass ratio M(CO + )/M(N + 2 ) = 0.999 598 887 74(11), an accuracy of 1 x 10 -10 . This is a factor of 4 improvement over previous measurements, and a factor of 10 better than the 1985 atomic mass table adjustment [WAA85a]. Much of the author's apparatus has been rebuilt, increasing the signal-to-noise ratio and improving the reliability of the machine. The typical time needed to make and cool a single ion has been reduced from about half an hour to under 5 minutes. This was done by a combination of faster ion-making and a much faster procedure for driving out ions of the wrong species. The improved S/N, in combination with a much better signal processing algorithm to extract the ion phase and frequency from the author's data, has substantially reduced the time required for the actual measurements. This is important now that the measurement time is a substantial fraction of the cycle time (the time to make a new ion and measure it). The improvements allow over 30 comparisons in one night, compared to 2 per night previously. This not only improves the statistics, but eliminates the possibility of large non-Gaussian errors due to sudden magnetic field shifts

  18. Single-ion nonlinear mechanical oscillator

    International Nuclear Information System (INIS)

    Akerman, N.; Kotler, S.; Glickman, Y.; Dallal, Y.; Keselman, A.; Ozeri, R.

    2010-01-01

    We study the steady-state motion of a single trapped ion oscillator driven to the nonlinear regime. Damping is achieved via Doppler laser cooling. The ion motion is found to be well described by the Duffing oscillator model with an additional nonlinear damping term. We demonstrate here the unique ability of tuning both the linear as well as the nonlinear damping coefficients by controlling the laser-cooling parameters. Our observations pave the way for the investigation of nonlinear dynamics on the quantum-to-classical interface as well as mechanical noise squeezing in laser-cooling dynamics.

  19. A fast online hit verification method for the single ion hit system at GSI

    International Nuclear Information System (INIS)

    Du, G.; Fischer, B.; Barberet, P.; Heiss, M.

    2006-01-01

    For a single ion hit facility built to irradiate specific targets inside biological cells, it is necessary to prove that the ions hit the selected targets reliably because the ion hits usually cannot be seen. That ability is traditionally tested either indirectly by aiming at pre-etched tracks in a nuclear track detector or directly by making the ion tracks inside cells visible using a stain coupled to special proteins produced in response to ion hits. However, both methods are time consuming and hits can be verified only after the experiment. This means that targeting errors in the experiment cannot be corrected during the experiment. Therefore, we have developed a fast online hit verification method that measures the targeting accuracy electronically with a spatial resolution of ±1 μm before cell irradiation takes place. (authors)

  20. Design and simulation of ion optics for ion sources for production of singly charged ions

    Science.gov (United States)

    Zelenak, A.; Bogomolov, S. L.

    2004-05-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments.

  1. Design and simulation of ion optics for ion sources for production of singly charged ions

    International Nuclear Information System (INIS)

    Zelenak, A.; Bogomolov, S.L.

    2004-01-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments

  2. Diode-like properties of single- and multi-pore asymmetric track membranes

    Science.gov (United States)

    Zielinska, K.; Gapeeva, A. R.; Orelovich, O. L.; Apel, P. Yu.

    2014-05-01

    In this work, we investigated the ionic transport properties of asymmetric polyethylene terephthalate (PET) track membranes with the thickness of 5 μm. The samples containing single pores and arrays of many pores were fabricated by irradiation with accelerated ions and subsequent physicochemical treatment. The method of etching in the presence of a surface-active agent was used to prepare the pores with highly-tapered tip. The transport of monovalent inorganic ions through the nano-scale holes was studied in a conductivity cell. The effective pore radii, electrical conductance and rectification ratios of pores were measured. The geometric characteristics of nanopores were investigated using FESEM.

  3. Effects of track structure and cell inactivation on the calculation of heavy ion mutation rates in mammalian cells

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Shavers, M. R.; Katz, R.

    1996-01-01

    It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to gamma-rays and the radial dose of the ions and may be equal to unity at small impact parameters for some ions. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections from heavy ions in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT mutations in Chinese hamster cells and good agreement is found. The resulting calculations qualitatively show that mutation cross sections for heavy ions display minima at velocities where inactivation cross sections display maxima. Also, calculations show the high probability of mutation by relativistic heavy ions due to the radial extension of ions track from delta-rays in agreement with the microlesion concept. The effects of inactivation on mutations rates make it very unlikely that a single parameter such as LET or Z*2/beta(2) can be used to specify radiation quality for heavy ion bombardment.

  4. Etching behaviour of alpha-recoil tracks in natural dark mica studied via artificial ion tracks

    International Nuclear Information System (INIS)

    Lang, M.; Glasmacher, U.A.; Neumann, R.; Wagner, G.A.

    2003-01-01

    Alpha-recoil tracks (ARTs) created by the α-decay of U, Th, and their daughter nuclei, are used by a new dating method to determine the formation age of dark mica bearing Quaternary and Neogene volcanic rocks and the cooling age of plutonic and metamorphic rocks [Chem. Geol. 166 (2000) 127, Science 155 (1967) 1103]. The age equation combines the volumetric density of ARTs with the U and Th contents. Etching latent ARTs (diameter 30-100 nm) in the mica mineral phlogopite by HF and measuring the areal density of triangular etch pits by optical and scanning force microscopy (SFM) leads to a linear growth of ART areal density versus etching time. The ART volume density is a function of the slope of the areal density and the etching rate (v eff ). Therefore, the determination of v eff is essential for the calculation of an age value. To determine the etching parameters such as etching efficiency and v eff , phlogopite samples were irradiated with 80 keV Au ions. Irradiated surfaces were etched with 4% HF at 23±2 deg. C during successive time intervals and after each interval studied with SFM. The etching rate v eff was determined by different techniques. To evaluate the threshold of etchability, the energy losses of the Au ions and α-recoil nuclei in phlogopite were calculated with the SRIM00 code. The etching efficiency of the Au ion tracks was then used to predict the corresponding etching efficiency of the natural radioactive nuclei

  5. Evaluation of Railway Networks with Single Track Operation Using the UIC 406 Capacity Method

    DEFF Research Database (Denmark)

    Landex, Alex

    2009-01-01

    lines and single track lines are discussed in this article. The principles of the UIC 406 of double track lines can be applied to single track lines-at least when more than one train follows each other in the same direction. In a presentation of the UIC 406 for single track operations, it is important...

  6. Single-organelle tracking by two-photon conversion

    Science.gov (United States)

    Watanabe, Wataru; Shimada, Tomoko; Matsunaga, Sachihiro; Kurihara, Daisuke; Fukui, Kiichi; Shin-Ichi Arimura, Shin-Ichi; Tsutsumi, Nobuhiro; Isobe, Keisuke; Itoh, Kazuyoshi

    2007-03-01

    Spatial and temporal information about intracellular objects and their dynamics within a living cell are essential for dynamic analysis of such objects in cell biology. A specific intracellular object can be discriminated by photoactivatable fluorescent proteins that exhibit pronounced light-induced spectral changes. Here, we report on selective labeling and tracking of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein with near-infrared femtosecond laser pulses. We performed selective labeling of a single mitochondrion in a living tobacco BY-2 cell using two-photon photoconversion of Kaede. Using this technique, we demonstrated that, in plants, the directed movement of individual mitochondria along the cytoskeletons was mediated by actin filaments, whereas microtubules were not required for the movement of mitochondria. This single-organelle labeling technique enabled us to track the dynamics of a single organelle, revealing the mechanisms involved in organelle dynamics. The technique has potential application in direct tracking of selective cellular and intracellular structures.

  7. Ion track annealing in quartz investigated by small angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Schauries, D.; Afra, B.; Rodriguez, M.D. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64287 Darmstadt (Germany); Hawley, A. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Kluth, P. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia)

    2015-12-15

    We report on the reduction of cross-section and length of amorphous ion tracks embedded within crystalline quartz during thermal annealing. The ion tracks were created via Au ion irradiation with an energy of 2.2 GeV. The use of synchrotron-based small angle X-ray scattering (SAXS) allowed characterization of the latent tracks, without the need for chemical etching. Temperatures between 900 and 1000 °C were required to see a notable change in track size. The shrinkage in cross-section and length was found to be comparable for tracks aligned perpendicular and parallel to the c-axis.

  8. Radial dose distribution around an energetic heavy ion and an ion track structure model

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Katsutoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ohno, Shin-ichi; Namba, Hideki; Taguchi, Mitsumasa; Watanabe, Ritsuko

    1997-03-01

    Ionization currents produced in a small wall-less ionization chamber located at varying distance from the 200 MeV Ni{sup 12+} ion`path traversing Ar gas were measured and utilized to construct a track structure model. Using the LET value of 200 MeV Ni{sup 12+} and G(Fe{sup 3+}) in Fricke solutions (= 15.4) for fast electrons, we estimate G(Fe{sup 3+}) for this ion to be 5.0. (author)

  9. Multi-Color Single Particle Tracking with Quantum Dots

    DEFF Research Database (Denmark)

    Christensen, Eva Arnspang; Brewer, J. R.; Lagerholm, B. C.

    2012-01-01

    . multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations......Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g...... further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image...

  10. Co-visualization of DNA damage and ion traversals in live mammalian cells using a fluorescent nuclear track detector

    International Nuclear Information System (INIS)

    Kodaira, Satoshi; Konishi, Teruaki; Kobayashi, Alisa

    2015-01-01

    The geometric locations of ion traversals in mammalian cells constitute important information in the study of heavy ion-induced biological effect. Single ion traversal through a cellular nucleus produces complex and massive DNA damage at a nanometer level, leading to cell inactivation, mutations and transformation. We present a novel approach that uses a fluorescent nuclear track detector (FNTD) for the simultaneous detection of the geometrical images of ion traversals and DNA damage in single cells using confocal microscopy. HT1080 or HT1080–53BP1-GFP cells were cultured on the surface of a FNTD and exposed to 5.1-MeV/n neon ions. The positions of the ion traversals were obtained as fluorescent images of a FNTD. Localized DNA damage in cells was identified as fluorescent spots of γ-H2AX or 53BP1-GFP. These track images and images of damaged DNA were obtained in a short time using a confocal laser scanning microscope. The geometrical distribution of DNA damage indicated by fluorescent γ-H2AX spots in fixed cells or fluorescent 53BP1-GFP spots in living cells was found to correlate well with the distribution of the ion traversals. This method will be useful for evaluating the number of ion hits on individual cells, not only for micro-beam but also for random-beam experiments. (author)

  11. The separation of heavy ion tracks in nuclear emulsions by means of the pulsed electric field

    International Nuclear Information System (INIS)

    Akopova, A.B.; Magradze, N.V.; Melkumyan, L.V.; Prokhorenko, Y.P.

    1976-01-01

    The pulsed electric field (PEF) technique is developed for the separation of heavy ion tracks from the intense background caused by high energy electrons, protons and γ-radiation. The tracks of Ne, Cr, Ar-ions accelerated at the Dubna Nuclear Reactions Laboratory have been separated from the background, the voltage of the applied PEF being 10 5 V/cm. (orig.) [de

  12. Electrochemical synthesis of metallic microstructures using etched ion tracks in nuclear track filters

    International Nuclear Information System (INIS)

    Sanjeev Kumar; Shyam Kumar; Rajesh Kumar; Chakravarti, K.

    2004-01-01

    Interest in nano/microstructures results from their numerous potential applications in various areas such as materials and biomedical sciences, electronics, optics, magnetism, energy storage and electrochemistry. Materials with micro/nanoscopic dimensions not only have potential technological applications in areas such as device technology and drug delivery, but also are of fundamental interest in that the properties of a material can change in this regime of transition between the bulk and molecular scales. Electrodeposition is a versatile technique combining low processing cost with ambient conditions that can be used to prepare metallic, polymeric and semiconducting microstructures. In the present work ion track membranes of Makrofol (KG) have been used as templates for synthesis of metallic microstructures using the technique of electrodeposition. (author)

  13. Spin resonance strength calculation through single particle tracking for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The strengths of spin resonances for the polarized-proton operation in the Relativistic Heavy Ion Collider are currently calculated with the code DEPOL, which numerically integrates through the ring based on an analytical approximate formula. In this article, we test a new way to calculate the spin resonance strengths by performing Fourier transformation to the actual transverse magnetic fields seen by a single particle traveling through the ring. Comparison of calculated spin resonance strengths is made between this method and DEPOL.

  14. Determination of ion track and shapes with damage simulations on the base of ellipsometric and backscattering spectrometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Polgar, O.; Fried, M.; Khanh, N.; Petrik, P.; Barsony, I. [Research Institute for Technical Phisycs and Materials Science, Budapest (Hungary)

    2008-05-15

    On the base of geometrical and statistical considerations a damage simulator was created in order to determine the ion track-radius and -shape of ion-implantation caused damage in single-crystalline Si. Damage vs. dose curves calculated by spectroscopic ellipsometry (SE) and Rutherford backscattering/channeling spectrometry (RBS/C) measurements, using different doses of 100 keV Xe implantation, gave information about the damage profile in depth. Both methods are required, because of dose-dependent discrepancies of SE compared with RBS/C [Fried et al., Thin Solid Films 455/456, 404 (2004)]. Different kinds of damage models were investigated to calculate the ion track-radius and to describe the damages in depth and the shape of ion track. Comparing directly the simulated and the measured damage vs. dose curves, the damage function and the other simulation parameters were optimized and hence the ion track size and even the shape can be determined. The dose dependent mean size of the unchanged crystalline regions, obtained from the simulation was correlated with the complex dielectric functions, obtained from the SE analysis. The results clearly show the effect of decreasing size of the unchanged crystalline regions. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Single track and single layer formation in selective laser melting of niobium solid solution alloy

    Directory of Open Access Journals (Sweden)

    Yueling GUO

    2018-04-01

    Full Text Available Selective laser melting (SLM was employed to fabricate Nb-37Ti-13Cr-2Al-1Si (at% alloy, using pre-alloyed powders prepared by plasma rotating electrode processing (PREP. A series of single tracks and single layers under different processing parameters was manufactured to evaluate the processing feasibility by SLM, including laser power, scanning speed, and hatch distance. Results showed that continuous single tracks could be fabricated using proper laser powers and scanning velocities. Both the width of a single track and its penetration depth into a substrate increased with an increase of the linear laser beam energy density (LED, i.e., an increase of the laser power and a decrease of the scanning speed. Nb, Ti, Si, Cr, and Al elements distributed heterogeneously over the melt pool in the form of swirl-like patterns. An excess of the hatch distance was not able to interconnect neighboring tracks. Under improper processing parameters, a balling phenomenon occurred, but could be eliminated with an increased LED. This work testified the SLM-processing feasibility of Nb-based alloy and promoted the application of SLM to the manufacture of niobium-based alloys. Keywords: Additive manufacturing, Melt pool, Niobium alloy, Powder metallurgy, Selective laser melting

  16. Development of pulsation technique for single ion hit system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Takuro; Hamano, Tsuyoshi; Hirao, Toshio; Kamiya, Tomihiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-12-01

    When a high energy heavy ion enters into a substance, high density of ionization and excitement occurrs along its flying trace. Especially, when such an ion enters into a semiconductor cell, a bit inversion called single event is occurred or a phenomenon destroyed element itself on case of the worst is formed. The present semiconductor cell is made in a size of some micron square, as different from its accumulated degree. In order to analyze the single event phenomenon formed by entering ion into such fine region in detail, a technique possible enter heavy ion beam with space resolution under 1 micron to each sample is necessary. In order to develop this technique, a static type high speed beam switch for control of entering a beam into a sample and a single ion detector for detecting entrance of ion into the sample were installed to heavy ion microbeam forming apparatus. The single ion hit system in Takasaki Radiation Chemistry Research Establishment, JAERI succeeded in detection and control technique of the single ion and control of noise due to pulsization and finished development of basic technique of the single ion hit, since now. After today, it is planned to hit actually the single ion onto the sample and evaluate its accuracy. (G.K.)

  17. CR-39 nuclear track detector application for the diagnostics of low energy high power ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Opekounov, M S; Pechenkin, S A; Remnev, G E [Nuclear Physics Institute, Tomsk (Russian Federation); Ivonin, I V [Siberian Physical-Technical Institute, Tomsk (Russian Federation)

    1997-12-31

    The results of investigation of the spectral composition of ion beams generated by the magneto-insulated ion diode of the MUK-M and TEMP accelerators. The energy and mass characteristics of the accelerated ion beam were determined by a Thomson spectrometer with a CR-39 plate detector (MOM - Atomki Nuclear Track Detector, Type MA-ND/p). The accelerated ion energy was from 40 to 240 keV. The ion current density range was from 1 to 10 A/cm{sup 2}. The mass composition contained hydrogen, nitrogen, carbon and aluminum ions. The individual track analysis showed the track form, depth and diameter in dependence on the ion mass and energy. (author). 2 figs., 5 refs.

  18. CR-39 track detector for multi-MeV ion spectroscopy.

    Science.gov (United States)

    Jeong, T W; Singh, P K; Scullion, C; Ahmed, H; Hadjisolomou, P; Jeon, C; Yun, H; Kakolee, K F; Borghesi, M; Ter-Avetisyan, S

    2017-05-19

    We present the characteristics of track formation on the front and rear surfaces of CR-39 produced by laser-driven protons and carbon ions. A methodological approach, based on bulk etch length, is proposed to uniquely characterize the particle tracks in CR-39, enabling comparative description of the track characteristics in different experiments. The response of CR-39 to ions is studied based on the energy dependent growth rate of the track diameter to understand the intrinsic particle stopping process within the material. A large non-uniformity in the track diameter is observed for CR-39 with thickness matching with the stopping range of particles. Simulation and experimental results show the imprint of longitudinal range straggling for energetic protons. Moreover, by exploiting the energy dependence of the track diameter, the energy resolution (δE/E) of CR-39 for few MeV protons and Carbon ion is found to be about 3%.

  19. Multi-color single particle tracking with quantum dots.

    Directory of Open Access Journals (Sweden)

    Eva C Arnspang

    Full Text Available Quantum dots (QDs have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT. In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a lipid, biotin-cap-DPPE, in the cellular plasma membrane of live cells using four different colors of QDs; QD565, QD605, QD655, and QD705 as labels.

  20. A singly charged ion source for radioactive 11C ion acceleration

    Science.gov (United States)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-01

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  1. Detection of coloured tracks of heavy ion particles using photographic colour film

    International Nuclear Information System (INIS)

    Kuge, K.; Yasuda, N.; Kumagai, H.; Nakazawa, K.; Kobayashi, T.; Aoki, N.; Hasegawa, A.

    2001-01-01

    A photographic colour film, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour film consists of several layers and different colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in different colours represented differences of track depth and we also discussed the disadvantages of using commercial colour films. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the disadvantages

  2. Tracking Ultrafast Carrier Dynamics in Single Semiconductor Nanowire Heterostructures

    Directory of Open Access Journals (Sweden)

    Taylor A.J.

    2013-03-01

    Full Text Available An understanding of non-equilibrium carrier dynamics in silicon (Si nanowires (NWs and NW heterostructures is very important due to their many nanophotonic and nanoelectronics applications. Here, we describe the first measurements of ultrafast carrier dynamics and diffusion in single heterostructured Si nanowires, obtained using ultrafast optical microscopy. By isolating individual nanowires, we avoid complications resulting from the broad size and alignment distribution in nanowire ensembles, allowing us to directly probe ultrafast carrier dynamics in these quasi-one-dimensional systems. Spatially-resolved pump-probe spectroscopy demonstrates the influence of surface-mediated mechanisms on carrier dynamics in a single NW, while polarization-resolved femtosecond pump-probe spectroscopy reveals a clear anisotropy in carrier lifetimes measured parallel and perpendicular to the NW axis, due to density-dependent Auger recombination. Furthermore, separating the pump and probe spots along the NW axis enabled us to track space and time dependent carrier diffusion in radial and axial NW heterostructures. These results enable us to reveal the influence of radial and axial interfaces on carrier dynamics and charge transport in these quasi-one-dimensional nanosystems, which can then be used to tailor carrier relaxation in a single nanowire heterostructure for a given application.

  3. Coupled chemical reactions in dynamic nanometric confinement: Ag2O membrane formation during ion track etching

    Czech Academy of Sciences Publication Activity Database

    Hernandez, G. M.; Cruz, S. A.; Quintero, R.; Arellano, H. G.; Fink, Dietmar; Alfonta, L.; Mandabi, Y.; Kiv, A.; Vacík, Jiří

    2013-01-01

    Roč. 168, č. 9 (2013), s. 675-695 ISSN 1042-0150 Institutional support: RVO:61389005 Keywords : track * polymers * etching * chemistry * ions * nanostructure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.603, year: 2013

  4. Colored tracks of heavy ion particles recorded on photographic color film

    International Nuclear Information System (INIS)

    Kuge, K.; Yasuda, N.; Kumagai, H.; Aoki, N.; Hasegawa, A.

    2002-01-01

    A new method to obtain the three-dimensional information on nuclear tracks was developed using color photography. Commercial color films were irradiated with ion beam and color-developed. The ion tracks were represented with color images in which different depths were indicated by different colors, and the three-dimensional information was obtained from color changes. Details of this method are reported, and advantages and limitations are discussed in comparison with a conventional method using a nuclear emulsion

  5. Plastic flow produced by single ion impacts on metals

    International Nuclear Information System (INIS)

    Birtcher, R. C.

    1998-01-01

    Single ion impacts have been observed using in situ transmission electron microscopy and video recording with a time resolution of 33 milliseconds. Gold was irradiated at 50 K and room temperature. Single ion impacts produce holes, modify existing holes, and extrude material into the initial specimen hole and holes formed by other ion impacts. The same behavior is observed at both temperatures. At both temperatures, ion impacts result in craters and ejected material. Ion impacts produce more small craters than large ones for all ion masses, while heavier mass ions produce more and larger craters than lighter mass ions. This comparison is affected by the ion energy. As the energy of an ion is increased, the probability for deposition near the surface decreases and fewer craters are formed. For a given ion mass, crater production depends on the probability for displacement cascade production in the near surface region. Crater and holes are stable at room temperature, however, ion impacts near an existing crater may cause flow of material into the crater either reshaping or annihilating it. Holes and craters result from the explosive outflow of material from the molten zone of near-surface cascades. The outflow may take the form of molten material, a solid lid or an ejected particle. The surface is a major perturbation on displacement cascades resulting from ion impacts

  6. Energy dependent track structure parametrizations for protons and carbon ions based on nano-metric simulations

    International Nuclear Information System (INIS)

    Frauke, A.; Wilkens, J.J.; Villagrasa, C.; Rabus, H.

    2015-01-01

    The BioQuaRT project within the European Metrology Research Programme aims at correlating ion track structure characteristics with the biological effects of radiation and develops measurement and simulation techniques for determining ion track structure on different length scales from about 2 nm to about 10 μm. Within this framework, we investigate methods to translate track-structure quantities derived on a nanometer scale to macroscopic dimensions. Input data sets were generated by simulations of ion tracks of protons and carbon ions in liquid water using the Geant-4 Monte Carlo tool-kit with the Geant-4-DNA processes. Based on the energy transfer points - recorded with nanometer resolution - we investigated parametrizations of overall properties of ion track structure. Three different track structure parametrizations have been developed using the distances to the 10 next neighbouring ionizations, the radial energy distribution and ionisation cluster size distributions. These parametrizations of nanometer-scale track structure build a basis for deriving biologically relevant mean values which are essential in the clinical situation where each voxel is exposed to a mixed radiation field. (authors)

  7. Glucose determination using a re-usable enzyme-modified ion track membrane sensor

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Klinkovich, I.; Bukelman, O.; Marks, R.S.; Kiv, A.; Fuks, D.; Fahrner, W. R.; Alfonta, L.

    2009-01-01

    Roč. 24, č. 8 (2009), s. 2702-2706 ISSN 0956-5663 Institutional research plan: CEZ:AV0Z10480505 Keywords : Glucose sensor * etched tracks * Ion track membranes Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 5.429, year: 2009

  8. Single ion counting with a MCP (microchannel plate) detector

    Energy Technology Data Exchange (ETDEWEB)

    Tawara, Hiroko; Sasaki, Shinichi; Miyajima, Mitsuhiro [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Shibamura, Eido

    1996-07-01

    In this study, a single-ion-counting method using alpha-particle-impact ionization of Ar atoms is demonstrated and the preliminary {epsilon}{sub mcp} for Ar ions with incident energies of 3 to 4.7 keV is determined. The single-ion counting by the MCP is aimed to be performed under experimental conditions as follows: (1) A signal from the MCP is reasonably identified as incidence of single Ar-ion. (2) The counting rate of Ar ions is less than 1 s{sup -1}. (3) The incident Ar ions are not focused on a small part of an active area of the MCP, namely, {epsilon}{sub mcp} is determined with respect to the whole active area of the MCP. So far, any absolute detection efficiency has not been reported under these conditions. (J.P.N.)

  9. Improvement of the Energy Stability of the Single Ion Microbeam

    International Nuclear Information System (INIS)

    Zhan Furu; Qi Xuehong; Xu Mingliang; Chen Lianyun; Yu Zengliang

    2008-01-01

    Energy instability strongly affects the state and the beam size of the single ion microbeam. A facility based on the Generating Voltmeter was developed to improve the energy stability of the CAS-LIBB (Chinese Academy of Sciences, key laboratory of ion beam bioengineering) single ion microbeam. This paper presents the analysis of the energy instability of the single ion microbeam. A simplified theoretical model is set up to calculate the relationship between the energy instability and the beam spot size. By using this technique, the energy instability is adjusted to about 1%. Stable run-time is over 6 hours. The radius of the single ion beam is reduced by 10% compared to the previous one.

  10. Single ion implantation for single donor devices using Geiger mode detectors

    International Nuclear Information System (INIS)

    Bielejec, E; Seamons, J A; Carroll, M S

    2010-01-01

    Electronic devices that are designed to use the properties of single atoms such as donors or defects have become a reality with recent demonstrations of donor spectroscopy, single photon emission sources, and magnetic imaging using defect centers in diamond. Ion implantation, an industry standard for atom placement in materials, requires augmentation for single ion capability including a method for detecting a single ion arrival. Integrating single ion detection techniques with the single donor device construction region allows single ion arrival to be assured. Improving detector sensitivity is linked to improving control over the straggle of the ion as well as providing more flexibility in lay-out integration with the active region of the single donor device construction zone by allowing ion sensing at potentially greater distances. Using a remotely located passively gated single ion Geiger mode avalanche diode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of >75 μm from the center of the collecting junction. This detection efficiency is achieved with sensitivity to ∼600 or fewer electron-hole pairs produced by the implanted ion. Ion detectors with this sensitivity and integrated with a thin dielectric, for example a 5 nm gate oxide, using low energy Sb implantation would have an end of range straggle of -1 and 10 -4 for operation temperatures of ∼300 K and ∼77 K, respectively. Low temperature operation and reduced false, 'dark', counts are critical to achieving high confidence in single ion arrival. For the device performance in this work, the confidence is calculated as a probability of >98% for counting one and only one ion for a false count probability of 10 -4 at an average ion number per gated window of 0.015.

  11. Track structure of protons and other light ions in liquid water: applications of the LIonTrack code at the nanometer scale.

    Science.gov (United States)

    Bäckström, G; Galassi, M E; Tilly, N; Ahnesjö, A; Fernández-Varea, J M

    2013-06-01

    The LIonTrack (Light Ion Track) Monte Carlo (MC) code for the simulation of H(+), He(2+), and other light ions in liquid water is presented together with the results of a novel investigation of energy-deposition site properties from single ion tracks. The continuum distorted-wave formalism with the eikonal initial state approximation (CDW-EIS) is employed to generate the initial energy and angle of the electrons emitted in ionizing collisions of the ions with H2O molecules. The model of Dingfelder et al. ["Electron inelastic-scattering cross sections in liquid water," Radiat. Phys. Chem. 53, 1-18 (1998); "Comparisons of calculations with PARTRAC and NOREC: Transport of electrons in liquid water," Radiat. Res. 169, 584-594 (2008)] is linked to the general-purpose MC code PENELOPE/penEasy to simulate the inelastic interactions of the secondary electrons in liquid water. In this way, the extended PENELOPE/penEasy code may provide an improved description of the 3D distribution of energy deposits (EDs), making it suitable for applications at the micrometer and nanometer scales. Single-ionization cross sections calculated with the ab initio CDW-EIS formalism are compared to available experimental values, some of them reported very recently, and the theoretical electronic stopping powers are benchmarked against those recommended by the ICRU. The authors also analyze distinct aspects of the spatial patterns of EDs, such as the frequency of nearest-neighbor distances for various radiation qualities, and the variation of the mean specific energy imparted in nanoscopic targets located around the track. For 1 MeV/u particles, the C(6+) ions generate about 15 times more clusters of six EDs within an ED distance of 3 nm than H(+). On average clusters of two to three EDs for 1 MeV/u H(+) and clusters of four to five EDs for 1 MeV/u C(6+) could be expected for a modeling double strand break distance of 3.4 nm.

  12. An ion beam tracking system based on a parallel plate avalanche counter

    International Nuclear Information System (INIS)

    Carter, I. P.; Ramachandran, K.; Dasgupta, M.; Hinde, D. J.; Rafiei, R.; Luong, D. H.; Williams, E.; Cook, K. J.; McNeil, S.; Rafferty, D. C.; Harding, A. B.; Muirhead, A. G.; Tunningley, T.

    2013-01-01

    A pair of twin position-sensitive parallel plate avalanche counters have been developed at the Australian National University as a tracking system to aid in the further rejection of unwanted beam particles from a 6.5 T super conducting solenoid separator named SOLEROO. Their function is to track and identify each beam particle passing through the detectors on an event-by-event basis. In-beam studies have been completed and the detectors are in successful operation, demonstrating the tracking capability. A high efficiency 512-pixel wide-angle silicon detector array will then be integrated with the tracking system for nuclear reactions studies of radioactive ions. (authors)

  13. Measurements of diameters of selectively etchable tracks produced in polymer by heavy ions

    International Nuclear Information System (INIS)

    Apel', P.Yu.

    1981-01-01

    The process of pore formation in polyethyleneterephtalate films irradiated by the 136 Xe, 84 Kr, 40 Ar ions was investigated by measuring the conductivity of the samples during etching. The diameters of the damaged tracks within which the local etching rate was larger than etching rate for non-destroyed polymer were determined. In the case of the 136 Xe ions measurements have been carried out at different ion energies [ru

  14. Probing Surface Electric Field Noise with a Single Ion

    Science.gov (United States)

    2013-07-30

    potentials is housed inside a Faraday cage providing more than 40 dB of attenuation for electromagnetic fields in the range of frequencies between 200...and measuring the ion quantum state [16]. Thus, by measuring the effect of electric field noise on the motional quantum state of the ion, one can probe...understand these effects . In summary, we have probed the electric field noise near an aluminum-copper surface at room temperature using a single trapped ion

  15. Theoretical and experimental study of single particle tracking in extreme conditions: single photon imaging

    International Nuclear Information System (INIS)

    Cajgfinger, T.

    2012-10-01

    This manuscript presents my thesis on the high frame rate (500 frames / second) single-photon detector electron-bombarded CMOS (ebCMOS). The first section compares three ultra-sensitive detectors and their methods for improving photon sensitivity: the CMOS low noise (sCMOS), the electron-multiplying CCD (emCCD) with signal multiplication by pixel and the ebCMOS with amplification by applied electric field. The method developed to detect single photon impacts with intra-pixel resolution on the ebCMOS sensor is presented. The second section compares the localization accuracy of these detectors in extreme conditions of very low photon flux (<10 photons/frame). First the theoretical limit is calculated using the Cramer-Rao lower bound for significant parameter sets. An experimental comparison of the detectors is then described. The setup provides one or more point sources controlled in position, signal and background noise. The results allow a comparison of the experimental effectiveness, purity and localization accuracy. The last section describes two experiments with the ebCMOS camera. The first aims at tracking hundreds of quantum dots simultaneously at the Nanoptec center. The second focuses on the swimming of bacteria at the surface at the Joliot Curie Institute. The point sources tracking algorithm using single photons and the Kalman filter implementation developed for these experiments is also described. (author)

  16. Single-ion conducting diblock terpolymers for lithium-ion batteries

    Science.gov (United States)

    Morris, Melody; Epps, Thomas H., III

    Block polymer (BP) electrolytes provide an attractive route to overcome the competing constraints of high conductivity and mechanical/thermal stability in lithium-ion batteries through nanoscale self-assembly. For example, macromolecules can be engineered such that one domain conducts lithium ions and the other prevents lithium dendrite formation. Herein, we report on the behavior of a single-ion conducting BP electrolyte that was designed to facilitate the transport of lithium ions. These polymers differ from traditional salt-doped BP electrolytes, which require the addition of a lithium salt to bestow conductivity and typically suffer from substantial counterion motion that reduces efficiency. New single-ion BPs were synthesized, and the nanoscale morphologies were determined using small angle X-ray scattering and transmission electron microscopy. Electrolyte performance was measured using AC impedance spectroscopy and DC polarization, and the results were correlated to nanoscale morphology and ion content. Enhanced physical understanding of single-ion BPs was gained by connecting the ion mobility to the chemistry, chain structure, and ion content of the single-ion BP. These studies can be applied to other charged-neutral block polymers to elucidate the effects of ion content on self-assembly and macroscopic properties.

  17. Measured and calculated absorptance of tracks of fast heavy ions in Ilford G5 nuclear emulsion

    International Nuclear Information System (INIS)

    Jensen, M.; Mathiesen, O.

    1975-04-01

    A modified form of the delta-ray theory of track formation developed by Katz and coworkers has been used to calculate the absorptance of tracks of fast heavy ions in Ilford G5 nuclear emulsion. The theoretical data have been compared with results of different photometrical investigations reported in the literature. In most cases the theoretical predictions are found to be in good agreement with experiments. This suggests that the theory can be used in the planning and execution of future experiments, i.e. to optimize the geometry of the photometer and to obtain an absolute charge calibration of the detector. It is shown that the basic photometrical properties of an emulsion stack can be described by a single quantity which can be determined from measurements. Knowing this quantity it is possible to predict the response of the emulsion stack for different types of photometers. The practical limits of the use of the modified theory at high and low levels of energy dose are discussed. (Auth.)

  18. Measured and calculated absorptance of tracks of fast heavy ions in Ilford G5 nuclear emulsion

    International Nuclear Information System (INIS)

    Jensen, M.; Mathiesen, O.

    1976-01-01

    A modified form of the delta-ray theory of track formation developed by Katz and coworkers has been used to calculate the absorptance of tracks of fast heavy ions in Ilford G5 nuclear emulsion. The theoretical data have been compared with results of different photometrical investigations reported in the literature. In most cases the theoretical predictions are found to be in good agreement with experiments. This suggests that the theory can be used in the planning and execution of future experiments, i.e. to optimize the geometry of the photometer and to obtain an absolute charge calibration of the detector. It is shown that the basic photometrical properties of an emulsion stack can be described by a single quantity which can be determined from measurements. Knowing this quantity it is possible to predict the response of the detector system, for different types of photometers. The practical limits of the use of the modified theory at high and low levels of energy dose are discussed. (Auth.)

  19. Conductometric determination of single pores in polyethyleneterephthalate irradiated by heavy ions

    International Nuclear Information System (INIS)

    Oganesyan, V.R.; Trofimov, V.V.; Doerschel, B.; Hermsdorf, D.; Vetter, J.; Danziger, M.

    2002-01-01

    Most of the previous works devoted to the problem of track formation processes did not pay enough attention to direct measurement of the appearance of every individual pore in an array of many pores induced by the irradiation of polymer films with ions. Such measurements are not easy to carry out due to the extremely high electric resistance in the moment of pore opening. In this work the analysis of films irradiated with low particle fluences up to 3.7·10 3 ions/cm 2 is described. Polyethyleneterephthalate (PET) Hostaphan with a thickness of 20μm was used. The samples were irradiated with Bi ions of 11.4 MeV/amu energy. Using optimized etching conditions and computer aided data evaluation, we obtained results, which are in good agreement with theoretical predictions and model calculations. The measured increase of conductivity beginning from the breakthrough of a single track up to the next pore opening in dependence on the etching time and the number of opened pores confirm the assumed model. Thus, the developed 'track-by-track' method can be used effectively for description of the sequential appearance of individual pores in an electrolytic etching process

  20. Single-track handshake signaling with application to micropipelines and handshake circuits

    NARCIS (Netherlands)

    Berkel, van C.H.; Bink, A.J.

    1996-01-01

    Single-track handshake signaling is using the same wire for request and acknowledge signaling. After each 2-phase handshake the wire is back in its initial state. A sequence of three protocol definitions suggests both a design method for single-track circuits and a trade-off between their robustness

  1. Irradiation effect of different heavy ions and track section on the silkworm Bombyx mori

    International Nuclear Information System (INIS)

    Tu Zhenli; Kobayashi, Yasuhiko; Kiguchi, Kenji; Watanabe, Hiroshi

    2003-01-01

    In order to compare the irradiation effects of different ions, wandering larvae were whole-body exposed or locally irradiated with 50-MeV 4 He 2+ , 220-MeV 12 C 5+ , and 350-MeV 20 Ne 8+ ions, respectively. For the whole-body-exposed individuals, the survival rates at the cocooning, pupation, and emergence stages all decreased as dose increased, and a range-dependent difference was clearly observed. For local irradiation of ovaries, irradiation effects depend very strongly on the projectile range. In the case of local irradiation of dermal cells by different track sections of heavy ions, the closer the target was to the high-LET section of the track, the more pronounced were the radiation effects. These results indicated that by selectively using ion species and adjusting the irradiation depth to the target, heavy-ion radiosurgery on particular tissues or organs of small experimental animals can be performed more accurately

  2. Nuclear tracks in CR-39 produced by carbon, oxygen, aluminium and titanium ions.

    Science.gov (United States)

    Rickards, J; Romo, V; Golzarri, J I; Espinosa, G

    2002-01-01

    This work describes the response of CR-39 (allyl diglycol polycarbonate) to different ions (C, O, Al and Ti) produced by the Instituto de Fisica 3 MV 9SDH-2 Pelletron accelerator and backscattered from a thin Au film on a C support. The ion energies were chosen in series such that the ranges of the different ions in the detector were 2, 3, 4, 5, 6, 7 and 8 microm respectively for each series. Once exposed, the detectors were etched with a solution of 6.25 M KOH at 60 degrees C, and the reading was carried out using a digital image analysis system. An analysis of the measured track diameters of all the types of ions indicates that, for a given range, track kinetics are independent of type of ion, energy and stopping power.

  3. Heavy ion and proton-induced single event multiple upset

    International Nuclear Information System (INIS)

    Reed, R.A.; Carts, M.A.; Marshall, P.W.

    1997-01-01

    Individual ionizing heavy ion events are shown to cause two or more adjacent memory cells to change logic states in a high density CMOS SRAM. A majority of the upsets produced by normally incident heavy ions are due to single-particle events that causes a single cell to upset. However, for grazing angles a majority of the upsets produced by heavy-ion irradiation are due to single-particle events that cause two or more cells to change logic states. Experimental evidence of a single proton-induced spallation reaction that causes two adjacent memory cells to change logic states is presented. Results from a dual volume Monte-Carlo simulation code for proton-induced single-event multiple upsets are within a factor of three of experimental data for protons at normal incidence and 70 degrees

  4. Transport of secondary electrons and reactive species in ion tracks

    Science.gov (United States)

    Surdutovich, Eugene; Solov'yov, Andrey V.

    2015-08-01

    The transport of reactive species brought about by ions traversing tissue-like medium is analysed analytically. Secondary electrons ejected by ions are capable of ionizing other molecules; the transport of these generations of electrons is studied using the random walk approximation until these electrons remain ballistic. Then, the distribution of solvated electrons produced as a result of interaction of low-energy electrons with water molecules is obtained. The radial distribution of energy loss by ions and secondary electrons to the medium yields the initial radial dose distribution, which can be used as initial conditions for the predicted shock waves. The formation, diffusion, and chemical evolution of hydroxyl radicals in liquid water are studied as well. COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy.

  5. Funnel-type etched ion tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Munoz, G. H.; Alfonta, L.; Klinkovich, I.

    2010-01-01

    Roč. 165, č. 5 (2010), s. 343-361 ISSN 1042-0150 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : tracks * polymers * etching Subject RIV: JJ - Other Materials Impact factor: 0.660, year: 2010

  6. Single-Photon Tracking for High-Speed Vision

    Directory of Open Access Journals (Sweden)

    Istvan Gyongy

    2018-01-01

    Full Text Available Quanta Imager Sensors provide photon detections at high frame rates, with negligible read-out noise, making them ideal for high-speed optical tracking. At the basic level of bit-planes or binary maps of photon detections, objects may present limited detail. However, through motion estimation and spatial reassignment of photon detections, the objects can be reconstructed with minimal motion artefacts. We here present the first demonstration of high-speed two-dimensional (2D tracking and reconstruction of rigid, planar objects with a Quanta Image Sensor, including a demonstration of depth-resolved tracking.

  7. Strategies towards advanced ion track-based biosensors

    Czech Academy of Sciences Publication Activity Database

    Alfonta, L.; Bukelman, O.; Chandra, A.; Fahrner, W. R.; Fink, D.; Fuks, D.; Golovanov, V.; Hnatowicz, Vladimír; Hoppe, K.; Kiv, A.; Klinkovich, I.; Landau, M.; Morante, J.R.; Tkachenko, N.V.; Vacík, Jiří; Valden, M.

    2009-01-01

    Roč. 164, 7-8 (2009), s. 431-437 ISSN 1042-0150. [2nd International Meeting on Recent Developments in the Study of Radiation Effects in Matters. Fodele, 07.09.2008-11.09.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : biosensors * etched tracks * enzymes Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.550, year: 2009

  8. Artificial ion tracks in volcanic dark mica simulating natural radiation damage: A scanning force microscopy study

    International Nuclear Information System (INIS)

    Lang, M.; Glasmacher, U.A.; Moine, B.; Mueller, C.; Neumann, R.; Wagner, G.A.

    2002-01-01

    A new dating technique uses alpha-recoil tracks (ART), formed by the natural α-decay of U, Th and their daughter products, to determine the formation age of Quaternary volcanic rocks ( 6 a). Visualization of etched ART by scanning force microscopy (SFM) enables to access track densities beyond 10 8 cm -2 and thus extend the new ART-dating technique to an age range >10 6 a. In order to simulate natural radiation damage, samples of phlogopite, originating from Quaternary and Tertiary volcanic rocks of the Eifel (Germany) and Kerguelen Islands (Indian Ocean) were irradiated with U, Ni (11.4 MeV/u), Xe, Cr, Ne (1.4 MeV/u) and Bi (200 keV) ions. After irradiation and etching with HF at various etching times, phlogopite surfaces were visualized by SFM. Hexagonal etch pits are typical of U, Xe and Cr ion tracks, but the etch pits of Ni, Ne and Bi ion tracks are triangular. Surfaces irradiated with U, Xe, Cr and Ni ions do not show any significant difference between etch pit density and irradiation fluence, whereas the Ne-irradiated surface show ∼14 times less etch pit density. The etching rate v H (parallel to cleavage) depends on the chemical composition of the phlogopite. The etching rate v T ' (along the track) increases with energy loss

  9. Laser radiation effect on radiation-induced defects in heavy ion tracks in dielectrics

    International Nuclear Information System (INIS)

    Egorov, A.N.; Zhiryakov, B.M.; Kushin, V.V.; Lyapidevskij, V.K.; Khokhlov, N.B.

    1988-01-01

    Possibility of laser radiation resonance effect on radiation-induced defects in heavy ion tracks in dielectric materials is investigated. Absorption spectra in infrared, visible and ultraviolet ranges for cellulose nitrate samples irradiated by 6 MeV/nucleon 58 Ni ions and reactor gamma radiation are measured. Absorption spectra for irradiated and reference samples are presented. Two absorption bands λ 1 =0.33 μm (E 1 =3.9 eV) and λ 2 =0.72 μm (E 2 =1.7 eV) are detected. Etching rate decrease in a track under laser radiation effect is noticed. 3 refs.; 1 fig

  10. Auger processes in tracks of fast multicharged ions

    International Nuclear Information System (INIS)

    Katin, V.V.; Martynenko, Yu.V.; Yavlinskij, Yu.N.

    1992-01-01

    The fast multicharged ion spends about 40% of energy losses on vacancy creation in the inner electron shells. This energy is transferred to the kinetic energy of electrons due to the cascade of Auger processes during ∼ 10 -14 s whereas the primary excited electrons receive the energy in ∼10 -16 s. (author)

  11. SAXS investigation of latent track structure in HDPE irradiated with high energy Fe ions

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Yang; Huang, Can [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Mingwang [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Institute of Electronic Engineering, CAEP, Mianyang 621900 (China); Liu, Qi; Wang, Yuzhu; Liu, Yi; Tian, Feng; Lin, Jun [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhu, Zhiyong, E-mail: zhuzhiyong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-08-01

    Semi-crystalline high density polyethylene (HDPE) samples were irradiated with 1.157 GeV {sup 56}Fe ion beams to fluences ranging from 1 × 10{sup 11} to 6 × 10{sup 12} ions/cm{sup 2}. The radiation induced changes in nano/microstructure were investigated with small angle X-ray scattering (SAXS) technique. The scattering contributions from HDPE matrix and ion tracks are successfully separated and analyzed through tilted SAXS measurements with respect to the X-ray beam direction. Lorentz correction, one-dimensional correlation function calculation, fractal nature analysis of the isotropic scattering pattern reveal that HDPE long period polymeric structures are damaged and new materials, possibly clusters of carbon-rich materials, are formed inside the ion tracks. Least square curve fitting of the scattering contribution from the ion track reveals that the track is composed of a core of about 5.3 nm in radius, characterized by a significant density deficit compared to the virgin HDPE, surrounded by a shell of about 4.3 nm in thickness with less density reduction.

  12. Ion implantation induced blistering of rutile single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Bing-Xi [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Jiao, Yang [College of Physics and Electronics, Shandong Normal University, Jinan, Shandong 250100 (China); Guan, Jing [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Wang, Lei [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China)

    2015-07-01

    The rutile single crystals were implanted by 200 keV He{sup +} ions with a series fluence and annealed at different temperatures to investigate the blistering behavior. The Rutherford backscattering spectrometry, optical microscope and X-ray diffraction were employed to characterize the implantation induced lattice damage and blistering. It was found that the blistering on rutile surface region can be realized by He{sup +} ion implantation with appropriate fluence and the following thermal annealing.

  13. Single Ion Trapping for the Enriched Xenon Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, Samuel J.; /Stanford U., Phys. Dept. /SLAC

    2006-03-28

    In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of {approx_equal} .010 eV.

  14. Spectroscopy and nonclassical fluorescence properties of single trapped Ba+ ions

    International Nuclear Information System (INIS)

    Bolle, J.

    1998-06-01

    This thesis reports on the setup and application of an experimental apparatus for spectroscopic and quantum optical investigations of a single Barium ion in a Paul trap. The realization of the apparatus, which consists of the ion trap in ultra high vacuum, two laser systems, and a photon counting detection system, is described in detail, with particular consideration of the noise sources like stray light and laser frequency instabilities. The two lasers at 493 nm and 650 nm needed to continuously excite resonance fluorescence from the Barium ion have been realized using diode lasers only. The preparation of a single localized Barium ion is described, in particular its optical cooling with the laser light and the minimization of induced vibration in the trapping potential. The purely quantum mechanical property of antibunching is observed by measuring the intensity correlation function of resonance fluorescence from the trapped and cooled ion. Interference properties of the single ion resonance fluorescence are investigated with a Mach-Zehnder interferometer. From the measured high-contrast interference signal it is proven that each individual fluorescence photon interferes with itself. The fluorescence excitation spectrum, on varying one laser frequency, is also measured and exhibits dark resonances. These measurements are compared to calculations based on optical Bloch equations for the 8 atomic levels involved. Future experiments, in particular the detection of reduced quantum fluctuations (squeezing) in one quadrature component of the resonance fluorescence, are discussed. (author)

  15. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

    Science.gov (United States)

    Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika

    2011-10-05

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms. © 2011 IOP Publishing Ltd

  16. Electron-ion correlation effects in ion-atom single ionization

    Energy Technology Data Exchange (ETDEWEB)

    Colavecchia, F.D.; Garibotti, C.R. [Centro Atomico Bariloche and Consejo Nacional de Investigaciones Cientificas y Tecnicas, 8400 San Carlos de Bariloche (Argentina); Gasaneo, G. [Departamento de Fisica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2000-06-28

    We study the effect of electron-ion correlation in single ionization processes of atoms by ion impact. We present a distorted wave model where the final state is represented by a correlated function solution of a non-separable three-body continuum Hamiltonian, that includes electron-ion correlation as coupling terms of the wave equation. A comparison of the electronic differential cross sections computed with this model with other theories and experimental data reveals that the influence of the electron-ion correlation is more significant for low energy emitted electrons. (author). Letter-to-the-editor.

  17. Measurement of energy deposition near heavy ion tracks

    International Nuclear Information System (INIS)

    Metting, N.F.; Brady, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Wong, M.; Schimmerling, W.; Rapkin, M.

    1985-01-01

    In November of 1982 work was begun in collaboration with Columbia University and Lawrence Berkeley Laboratory to use microdosimetric methods to measure energy deposition of heavy ions produced at LBL's Bevalac Biomedical Facility. Last year the authors reported preliminary results indicating that secondary charged particle equilibrium was probably obtained using this experimental setup, but that there seemed to be poor spatial resolution in the solid state position-sensitive detector. Further analysis of the measurements taken in August 1983 shows that because of this electronic noise in the position-sensitive detector, only the 56 Fe data yielded useful microdosimetric spectra

  18. Influence of asymmetric etching on ion track shapes in polycarbonate

    International Nuclear Information System (INIS)

    Clochard, M.-C.; Wade, T.L.; Wegrowe, J.-E.; Balanzat, E.

    2007-01-01

    By combining low-energy ion irradiation with asymmetric etching, conical nanopores of controlled geometry can be etched in polycarbonate (PC). Cone bases vary from 0.5 to 1 μm. Top diameters down to 17 nm are reached. When etching from one side, the pH on the other side (bathed in neutral or acidic buffer) was monitored. Etching temperature ranged from 65 deg. C to 80 deg. C. Pore shape characterization was achieved by electro replication combined with SEM observation. The tip shape depended on whether an acidic buffer was used or not on the stopped side

  19. Symphony and cacophony in ion track etching: how to control etching results

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Kiv, A.; Cruz, S. A.; Munoz, G. H.; Vacík, Jiří

    2012-01-01

    Roč. 167, č. 7 (2012), s. 527-540 ISSN 1042-0150 R&D Projects: GA AV ČR IAA200480702 Institutional support: RVO:61389005 Keywords : ion track s * polymers * etching * diodes * resistances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.502, year: 2012

  20. Large solid angle tracking of Monte Carlo events of heavy ion collisions in TPC magnetic spectrometers

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Asoka-Kumar, P.P.V.; Chan, C.S.; Kramer, M.A.

    1987-01-01

    The BNL/CCNY collaboration has for some time had as its goal the development and use of ≅ 4π solid angle magnetic spectrometer tracking of charged particles produced in heavy ion collision experiments at AGS, and eventually RHIC. (orig./HSI)

  1. High-accuracy fluence determination in ion beams using fluorescent nuclear track detectors

    DEFF Research Database (Denmark)

    Osinga, J.-M.; Akselrod, M.S.; Herrmann, Rochus

    2013-01-01

    We present an approach to use Al2O3:C,Mg-based fluorescent nuclear track detectors (FNTDs) and confocal laser scanning microscopy as a semiautomatic tool for fluence measurements in clinical ion beams. The method was found to cover a linear energy transfer (LET) range from at least L∞(Al2O3) = 0...

  2. Non-invasive monitoring of therapeutic carbon ion beams in a homogeneous phantom by tracking of secondary ions

    Science.gov (United States)

    Gwosch, K.; Hartmann, B.; Jakubek, J.; Granja, C.; Soukup, P.; Jäkel, O.; Martišíková, M.

    2013-06-01

    Radiotherapy with narrow scanned carbon ion beams enables a highly accurate treatment of tumours while sparing the surrounding healthy tissue. Changes in the patient’s geometry can alter the actual ion range in tissue and result in unfavourable changes in the dose distribution. Consequently, it is desired to verify the actual beam delivery within the patient. Real-time and non-invasive measurement methods are preferable. Currently, the only technically feasible method to monitor the delivered dose distribution within the patient is based on tissue activation measurements by means of positron emission tomography (PET). An alternative monitoring method based on tracking of prompt secondary ions leaving a patient irradiated with carbon ion beams has been previously suggested. It is expected to help in overcoming the limitations of the PET-based technique like physiological washout of the beam induced activity, low signal and to allow for real-time measurements. In this paper, measurements of secondary charged particle tracks around a head-sized homogeneous PMMA phantom irradiated with pencil-like carbon ion beams are presented. The investigated energies and beam widths are within the therapeutically used range. The aim of the study is to deduce properties of the primary beam from the distribution of the secondary charged particles. Experiments were performed at the Heidelberg Ion Beam Therapy Center, Germany. The directions of secondary charged particles emerging from the PMMA phantom were measured using an arrangement of two parallel pixelated silicon detectors (Timepix). The distribution of the registered particle tracks was analysed to deduce its dependence on clinically important beam parameters: beam range, width and position. Distinct dependencies of the secondary particle tracks on the properties of the primary carbon ion beam were observed. In the particular experimental set-up used, beam range differences of 1.3 mm were detectable. In addition, variations

  3. Mean range and energy of 28Si ions some Makrofol track detectors

    International Nuclear Information System (INIS)

    Shyam, S.; Mishra, R.; Tripathy, S.P.; Mawar, A.K.; Dwivedi, K.K.; Khathing, D.T.; Srivastava, A.; Avasthi, D.K.

    2000-01-01

    The rate of energy loss of the impinging ion as it passes through succeeding layers of the target material gives information regarding the nature of material and helps to calculate the range of the ions in a thick target in which the ions are stopped. Here the range, energy loss of 118 MeV 28 Si were measured in Makrofol-N, Makrofol-G and Makrofol-KG, using nuclear track technique. The experimental range data are compared with the theoretical values obtained from different computer codes. (author)

  4. Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

    Energy Technology Data Exchange (ETDEWEB)

    Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

    1986-08-01

    The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs.

  5. Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

    International Nuclear Information System (INIS)

    Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

    1986-08-01

    The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs

  6. Scanning probe microscopy of single Au ion implants in Si

    International Nuclear Information System (INIS)

    Vines, L.; Monakhov, E.; Maknys, K.; Svensson, B.G.; Jensen, J.; Hallen, A.; Kuznetsov, A. Yu.

    2006-01-01

    We have studied 5 MeV Au 2+ ion implantation with fluences between 7 x 10 7 and 2 x 10 8 cm -2 in Si by deep level transient spectroscopy (DLTS) and scanning capacitance microscopy (SCM). The DLTS measurements show formation of electrically active defects such as the two negative charge states of the divacancy (V 2 (=/-) and V 2 (-/0)) and the vacancy-oxygen (VO) center. It is observed that the intensity of the V 2 (=/-) peak is lower compared to that of V 2 (-/0) by a factor of 5. This has been attributed to a highly localized distribution of the defects along the ion tracks, which results in trapping of the carriers at V 2 (-/0) and incomplete occupancy of V 2 (=/-). The SCM measurements obtained in a plan view show a random pattern of regions with a reduced SCM signal for the samples implanted with fluence above 2 x 10 8 cm -2 . The reduced SCM signal is attributed to extra charges associated with acceptor states, such as V 2 (-/0), formed along the ion tracks in the bulk Si. Indeed, the electron emission rate from the V 2 (-/0) state is in the range of 10 kHz at room temperature, which is well below the probing frequency of the SCM measurements, resulting in 'freezing' of electrons at V 2 (-/0)

  7. Multi-physics modeling of single/multiple-track defect mechanisms in electron beam selective melting

    International Nuclear Information System (INIS)

    Yan, Wentao; Ge, Wenjun; Qian, Ya; Lin, Stephen; Zhou, Bin; Liu, Wing Kam; Lin, Feng; Wagner, Gregory J.

    2017-01-01

    Metallic powder bed-based additive manufacturing technologies have many promising attributes. The single track acts as one fundamental building unit, which largely influences the final product quality such as the surface roughness and dimensional accuracy. A high-fidelity powder-scale model is developed to predict the detailed formation processes of single/multiple-track defects, including the balling effect, single track nonuniformity and inter-track voids. These processes are difficult to observe in experiments; previous studies have proposed different or even conflicting explanations. Our study clarifies the underlying formation mechanisms, reveals the influence of key factors, and guides the improvement of fabrication quality of single tracks. Additionally, the manufacturing processes of multiple tracks along S/Z-shaped scan paths with various hatching distance are simulated to further understand the defects in complex structures. The simulations demonstrate that the hatching distance should be no larger than the width of the remelted region within the substrate rather than the width of the melted region within the powder layer. Thus, single track simulations can provide valuable insight for complex structures.

  8. Heavy ion microbeam system for study of single event effects

    International Nuclear Information System (INIS)

    Kamiya, Tomihiro; Utsunomiya, Nobuhiro; Minehara, Eiichi; Tanaka, Ryuichi; Ohmura, Miyoshi; Kohno, Kazuhiro; Iwamoto, Eiji.

    1992-01-01

    A high-energy heavy ion microbeam system has been developed and installed on a beam line of a 3 MV tandem electrostatic accelerator mainly for analysis of basic mechanism of single event upset (SEU) of semiconductor devices in spacecraft. The SEU is now the most serious problem for highly reliable spacecraft electronics system with long space mission. However, the mechanism has not been understood on the basis of microscopic process of SEU. The SEU phenomena depends not only upon hitting particles, but also upon the hit position on the microcircuit. To observe the transient charge pulse from a SEU, a single ion particle must hit exactly the desired position of the microcircuit. Such an experiment requires the microbeam spot size within 1 μm, the beam positioning accuracy within ±1 μm, and single ion hitting. The microbeam system has been designed to meet the above technical requirements. The system is equipped with two lens systems: one to control the target beam current in a wide range down to extremely low current without any change of the beam optics, and the other to focus heavy ion beams within a spot size of 1 μm. The final goal is to hit a microscopic target area with a single 15 MeV nickel ion. The beam spot size has been evaluated by Gaussian fitting of secondary electron profiles with microbeam scanning across the fine Cu mesh. The single ion detection has been also tested to generate a trigger signal for closing beam shutter to prevent further hits. This paper outlines the new microbeam system and describes methods to realize these techniques. (author)

  9. AFM studies on heavy ion irradiated YBCO single crystals

    International Nuclear Information System (INIS)

    Lakhani, Archana; Marhas, M.K.; Saravanan, P.; Ganesan, V.; Srinivasan, R.; Kanjilal, D.; Mehta, G.K.; Elizabeth, Suja; Bhat, H.L.

    2000-01-01

    Atomic Force Microscopy (AFM) is extensively used to characterise the surface morphology of high energy ion irradiated single crystals of high temperature superconductor - YBCO. Our earlier systematic studies on thin films of YBCO under high energy and heavy ion irradiation shows clear evidence of ion induced sputtering or erosion, even though the effect is more on the grain boundaries. These earlier results were supported by electrical resistance measurements. In order to understand more clearly, the nature of surface modification at these high energies, AFM studies were carried out on single crystals of YBCO. Single crystals were chosen in order to see the effect on crystallites alone without interference from grain boundaries. 200 MeV gold ions were used for investigation using the facilities available at Nuclear Science Centre, New Delhi. The type of ion and the range of energies were chosen to meet the threshold for electronically mediated defect production. The results are in conformity with our earlier studies and will be described in detail in the context of electronic energy loss mediated sputtering or erosion. (author)

  10. Features of single tracks in coaxial laser cladding of a NIbased self-fluxing alloy

    Directory of Open Access Journals (Sweden)

    Feldshtein Eugene

    2017-01-01

    Full Text Available In the present paper, the influence of coaxial laser cladding conditions on the dimensions, microstructure, phases and microhardness of Ni-based self-fluxing alloy single tracks is studied. The height and width of single tracks depend on the speed and distance of the laser cladding: increasing the nozzle distance from the deposited surface 1.4 times reduces the width of the track 1.2 - 1.3 times and increases its height 1.2 times. The increase of the laser spot speed 3 times reduces the track width 1.2 - 1.4 times and the height in 1.5 - 1.6 times. At the same time, the increase of the laser spot speed 3 times reduces the track width 1.2 - 1.4 times and the height 1.5 - 1.6 times. Regularities in the formation of single tracks microstructure with different cladding conditions are defined, as well as regularity of distribution of elements over the track depth and in the transient zone. The patterns of microhardness distribution over the track depth for different cladding conditions are found.

  11. Electronic energy loss of the latent track in heavy ion-irradiated polyimide

    International Nuclear Information System (INIS)

    Sun Youmei; Liu Jie; Zhang Chonghong; Wang Zhiguang; Jin Yunfan; Duan Jinglai; Song Yin

    2005-01-01

    In the interaction process of a swift heavy ion (SHI) and polymer, a latent track with radius of several nanometers appears near the ion trajectory due to the dense ionization and excitation. To describe the role of electronic energy loss (dE/dX) e , multi-layer stacks (with different dE/dX) of polyimide (PI) films were irradiated by different SHIs (1.158 GeV Fe 56 and 1.755 GeV Xe 136 ) under vacuum at room temperature. Chemical changes of modified PI films were studied by Fourier Transform Infrared (FTIR) spectroscopy. The main feature of SHI irradiation is the degradation of the functional group and creation of alkyne. The chain disruption rate of PI was investigated in the fluence range from 1 x 10 11 to 6 x 10 12 ions/cm 2 and a wider energy stopping power range (2.2 to 5.2 keV/nm for Fe 56 ions and 8.6 to 11.3 keV/nm for Xe 136 ions). Alkyne formation was observed over the electronic energy loss range of interest. Assuming the saturated track model (the damage process only occur in a cylinder of area σ), the mean degradation and alkyne formation radii in tracks were deduced for Fe and Xe ion irradiation, respectively. The results were validated by the thermal spike model and the threshold electronic energy loss of track formation S et in PI was deduced. The analysis of the irradiated PI films shows that the predictions of the thermal spike model are in qualitative agreement with the curve shape of experimental results. (authors)

  12. Sputtering of Au induced by single Xe ion impacts

    International Nuclear Information System (INIS)

    Birtcher, R. C.; Donnelly, S. E.

    1999-01-01

    Sputtering of Au thin films has been determined for Xe ions with energies between 50 and 600 keV. In-situ transmission electron microscopy was used to observe sputtered Au during deposition on a carbon foil near the specimen. Total reflection and transmission sputtering yields for a 62 nm thick Au thin film were determined by ex-situ measurement of the total amount of Au on the carbon foils. In situ observations show that individual Xe ions eject Au nanoparticles as large as 7 nm in diameter with an average diameter of approximately 3 nm. Particle emission correlates with crater formation due to single ion impacts. Nanoparticle emission contributes significantly to the total sputtering yield for Xe ions in this energy range in either reflection or transmission geometry

  13. Plastic Flow Induced by Single Ion Impacts on Gold

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Donnelly, S.E.

    1996-01-01

    The formation of holes in thin gold foils as a result of single ion impacts by 200keV Xe ions has been followed using transmission electron microscopy. Video recording provided details of microstructure evolution with a time resolution of 1/30th sec. Hole formation involves the movement by plastic flow of massive amounts of material, on the order of tens of thousands of Au atoms per ion impact. Plastic flow, as a consequence of individual ion impacts, results in a continual filling of both holes and craters as well as a thickening of the gold foil. Changes in morphology during irradiation is attributed to a localized, thermal-spike induced melting, coupled with plastic flow of effected material under the influence of surface forces. copyright 1996 The American Physical Society

  14. Single-ion irradiation: physics, technology and applications

    International Nuclear Information System (INIS)

    Ohdomari, Iwao

    2008-01-01

    Among the various radiation effects which involve the study of radiation environments, responses of materials and devices to radiation, radiation testing and radiation hardening of devices and equipment, this review mainly considers the radiation effects induced by alpha particles and other ions used in semiconductor technology on Si crystals and Si devices. We first describe the single-ion microprobe that enables the study of the site dependence of radiation hardness in a semiconductor device. Next, we describe single-ion implantation as a tool for suppressing fluctuation in device function induced by the discrete number and random position of dopant atoms. Finally, we describe the common features associated with both 'probing' and 'modification' in terms of the nature and behaviour of defect clusters induced by single-ion irradiation. A special feature of the review is that the radiation effects discussed here are induced by 'single' particles, and not by particle beams. Although there is a great amount of accumulated data on radiation effects, they are discussed in the conventional terms of 'dose' or 'fluence,' whose unit is cm -2 . Therefore, this review provides complementary information on radiation effects. (topical review)

  15. Tracking of Polycarbonate Films using Low-energy Ions Final Report CRADA No. TC-774-94

    Energy Technology Data Exchange (ETDEWEB)

    Musket, R. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2018-01-24

    Ion tracking is performed almost exclusively using ions with energies near or above the maximum in electronic stopping. For the present study, we have examined the results of etching ion tracks created by ions bombarding polycarbonate films with energies corresponding to stopping well below the maximum and just above the anticipated threshold for creating etchable latent tracks. Low-energy neon and argon ions with 18-60 keV /amu and fluences of about 108/cm2 were used to examine the limits for producing etchable tracks in polycarbonate films. By concentrating on the early stages of etching (i.e., -20 nm < SEM hole diameter < -100 nm), we can directly relate the energy deposition calculated for the incident ion to the creation of etchable tracks. The experimental results will be discussed with regard to the energy losses of the ions in the polycarbonate films and to the formation of continuous latent tracks through the entire thickness the films. These results have significant implications with respect to the threshold for formation of etchable tracks and to the use of low-energy ions for lithographic applications.

  16. Measurement of track opening contours of oblique incident 4He and 7Li-ions in CR-39: Relevance for calculation of track formation parameters

    International Nuclear Information System (INIS)

    Hermsdorf, D.; Reichelt, U.

    2010-01-01

    Solid State Nuclear Track Detectors (SSNTD) irradiated in realistic radiation fields exhibits after chemical etching very complex track images resulting from different species of particles and their energy spectra and randomly distributed angles of incidence or emission. Reading out such an etched detector surface with a light microscope, quite different track opening contours are observed. Beside the number of tracks, typically their major and minor axes are measured. In this work following problems arising from such experimental situations will be investigated: ·the measurement of track contour parameters for oblique incident 4 He and 7 Li-ions of different energies and angles in CR-39 detectors ·the theoretical description of the angular variation of both axes. ·the possibility to extract physical and spectroscopic information from major and minor track axes. This analysis is based on an intensive experimental program and the comprehensive study of theoretical models available for description of track revealing processes in CR-39.

  17. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    International Nuclear Information System (INIS)

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H.; Cleyrat, C.; Lidke, D. S.; Wilson, B. S.

    2015-01-01

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments

  18. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H., E-mail: jwerner@lanl.gov [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, New Mexico 87545 (United States); Cleyrat, C.; Lidke, D. S.; Wilson, B. S. [Department of Pathology and Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2015-12-15

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

  19. Single qubit manipulation in a microfabricated surface electrode ion trap

    Science.gov (United States)

    Mount, Emily; Baek, So-Young; Blain, Matthew; Stick, Daniel; Gaultney, Daniel; Crain, Stephen; Noek, Rachel; Kim, Taehyun; Maunz, Peter; Kim, Jungsang

    2013-09-01

    We trap individual 171Yb+ ions in a surface trap microfabricated on a silicon substrate, and demonstrate a complete set of high fidelity single qubit operations for the hyperfine qubit. Trapping times exceeding 20 min without laser cooling, and heating rates as low as 0.8 quanta ms-1, indicate stable trapping conditions in these microtraps. A coherence time of more than 1 s, high fidelity qubit state detection and single qubit rotations are demonstrated. The observation of low heating rates and demonstration of high quality single qubit gates at room temperature are critical steps toward scalable quantum information processing in microfabricated surface traps.

  20. Single qubit manipulation in a microfabricated surface electrode ion trap

    International Nuclear Information System (INIS)

    Mount, Emily; Baek, So-Young; Gaultney, Daniel; Crain, Stephen; Noek, Rachel; Kim, Taehyun; Maunz, Peter; Kim, Jungsang; Blain, Matthew; Stick, Daniel

    2013-01-01

    We trap individual 171 Yb + ions in a surface trap microfabricated on a silicon substrate, and demonstrate a complete set of high fidelity single qubit operations for the hyperfine qubit. Trapping times exceeding 20 min without laser cooling, and heating rates as low as 0.8 quanta ms −1 , indicate stable trapping conditions in these microtraps. A coherence time of more than 1 s, high fidelity qubit state detection and single qubit rotations are demonstrated. The observation of low heating rates and demonstration of high quality single qubit gates at room temperature are critical steps toward scalable quantum information processing in microfabricated surface traps. (paper)

  1. Using Single-Protein Tracking to Study Cell Migration.

    Science.gov (United States)

    Orré, Thomas; Mehidi, Amine; Massou, Sophie; Rossier, Olivier; Giannone, Grégory

    2018-01-01

    To get a complete understanding of cell migration, it is critical to study its orchestration at the molecular level. Since the recent developments in single-molecule imaging, it is now possible to study molecular phenomena at the single-molecule level inside living cells. In this chapter, we describe how such approaches have been and can be used to decipher molecular mechanisms involved in cell migration.

  2. Localization Spectroscopy of a Single Ion in an Optical Lattice

    DEFF Research Database (Denmark)

    Legrand, Olivier Philippe Alexandre

    2015-01-01

    The work reported in this thesis primarily focuses on studies of the dynamics of a single laser-cooled ion, simultaneously confined in the harmonic potential of a linear Paul trap and a rapidly varying periodic potential – a so-called optical lattice – generated from an optical standing-wave. Bes...... as a new tool for future cavity quantum electrodynamics experiments in the Ion trap group at Aarhus University.......-wave. Besides providing a better understanding of the dynamics of an ion subjected to varying trapping conditions, this work establishes a basis for future studies of various quantum many-body physics models, for manipulations of the structure of large ion Coulomb crystals, and for optimization...... of the interaction between light and matter in connection with quantum information experiments. In addition to the deep, three-dimensional harmonic potential of the linear Paul trap which confines the ion in regions of several millimeters, one of the directions of the ion motion is constrained by the application...

  3. Cavity QED with single trapped Ca+-ions

    International Nuclear Information System (INIS)

    Mundt, A.B.

    2003-02-01

    This thesis reports on the design and setup of a vacuum apparatus allowing the investigation of cavity QED effects with single trapped 40 Ca + ions. The weak coupling of ion and cavity in the 'bad cavity limit' may serve to inter--convert stationary and flying qubits. The ion is confined in a miniaturized Paul trap and cooled via the Doppler effect to the Lamb--Dicke regime. The extent of the atomic wave function is less than 30 nm. The ion is enclosed by a high finesse optical cavity. The technically--involved apparatus allows movement of the trap relative to the cavity and the trapped ion can be placed at any position in the standing wave. By means of a transfer lock the cavity can be resonantly stabilized with the S 1/2 ↔ D 5/2 quadrupole transition at 729 nm (suitable as a qubit) without light at that wavelength being present in the cavity. The coupling of the cavity field to the S 1/2 ↔ D 5/2 quadrupole transition is investigated with various techniques in order to determine the spatial dependence as well as the temporal dynamics. The orthogonal coupling of carrier and first--order sideband transitions at field nodes and antinodes is explored. The coherent interaction of the ion and the cavity field is confirmed by exciting Rabi oscillations with short resonant pulses injected into the cavity. Finally, first experimental steps towards the observation of cavity enhanced spontaneous emission have been taken. (author)

  4. Conductometric Determination of Single Pores in Polyethyleneterephthalate Irradiated by Heavy Ions

    CERN Document Server

    Oganesyan, V R; Dörschel, B; Vetter, J E; Danziger, M; Hermsdorf, D

    2002-01-01

    Most of previous works devoted to the problem of track formation processes did not pay enough attention to direct measurement of the appearance of every individual pore in an array of many pores induced by the irradiation of polymer films with ions. Such measurements are not easy to carry out due to the extremely high electric resistance in the moment of pore opening. In this work the analysis of films irradiated with low particle fluences up to 3.7\\cdot 10^{3} ions/cm^2 is described. Polyethyleneterephthalate (PET) Hostaphan with a thickness of 20 m was used. The samples were irradiated with Bi ions of 11.4 MeV/amu energy. Using optimized etching conditions and computer aided data evaluation we obtained results, which are in good agreement with theoretical predictions and model calculations. The measured increase of conductivity beginning from the breakthrough of a single track up to the next pore opening in dependence on the etching time and the number of opened pores confirm the assumed model. Thus, the de...

  5. Conductometric determination of single pores in polyethyleneterephthalate irradiated by heavy ions

    CERN Document Server

    Oganesyan, V R; Dörschel, B; Hermsdorf, D; Trofimov, V V; Vetter, J

    2002-01-01

    Most of the previous works devoted to the problem of track formation processes did not pay enough attention to direct measurement of the appearance of every individual pore in an array of many pores induced by the irradiation of polymer films with ions. Such measurements are not easy to carry out due to the extremely high electric resistance in the moment of pore opening. In this work the analysis of films irradiated with low particle fluences up to 3.7 centre dot 10 sup 3 ions/cm sup 2 is described. Polyethyleneterephthalate (PET) Hostaphan with a thickness of 20 mu m was used. The samples were irradiated with Bi ions of 11.4 MeV/amu energy. Using optimized etching conditions and computer aided data evaluation, we obtained results, which are in good agreement with theoretical predictions and model calculations. The measured increase of conductivity beginning from the breakthrough of a single track up to the next pore opening in dependence on the etching time and the number of opened pores confirm the assumed...

  6. Xe ion beam induced rippled structures on differently oriented single-crystalline Si surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hanisch, Antje; Grenzer, Joerg; Facsko, Stefan [Forschungszentrum Dresden-Rossendorf, Institut fuer Ionenstrahlphysik und Materialforschung, PO Box 510119, 01314 Dresden (Germany); Biermanns, Andreas; Pietsch, Ullrich, E-mail: A.Hanisch@fzd.d [Universitaet Siegen, Festkoerperphysik, 57068 Siegen (Germany)

    2010-03-24

    We report on Xe{sup +} induced ripple formation at medium energy on single-crystalline silicon surfaces of different orientations using substrates with an intentional miscut from the [0 0 1] direction and a [1 1 1] oriented wafer. The ion beam incidence angle with respect to the surface normal was kept fixed at 65{sup 0} and the ion beam projection was parallel or perpendicular to the [1 1 0] direction. By a combination of atomic force microscopy, x-ray diffraction and high-resolution transmission electron microscopy we found that the features of the surface and subsurface rippled structures such as ripple wavelength and amplitude and the degree of order do not depend on the surface orientation as assumed in recent models of pattern formation for semiconductor surfaces. (fast track communication)

  7. IODA - a fast, automated and flexible system for ion track analysis on film detectors

    International Nuclear Information System (INIS)

    Guth, H.; Hellmann, A.

    1995-02-01

    The IODA System (Ion Density Analysis) is used to analyse detector films, resulting from experiments at the pulse power generator KALIF (Karlsruhe Light Ion Facility). The system consists of evaluation software and a microcomputer, which controls a microscope, a video interface, and a multiprocessor subsystem. The segmentation of ion tracks is done automatically by means of digital image processing and pattern recognition. After defining an evaluation range and selecting a suitable analysis method, the film is scanned by the microscope for counting the impacts of the underlying image. According to the appearance of the ion tracks on the film, different methods can be selected. The evaluation results representing the ion density are stored in a matrix. The time needed for an evaluation at a high resolution can be shortened by shipping time consuming pattern recognition calculations to the multiprocessor subsystem. The bottlenecks of the system are the data transfer and the speed of the microscope stage. Simple handling of the system even on alphanumeric terminals had been an important design issue. This was implemented by a logically structured menue system including online help features. This report can be used a s a manual to support the user with system operation. (orig.) [de

  8. Irradiation effect of different heavy ions and track section on the silkworm Bombyx mori

    Energy Technology Data Exchange (ETDEWEB)

    Tu Zhenli E-mail: tu514@yahoo.co.jp; Kobayashi, Yasuhiko; Kiguchi, Kenji; Watanabe, Hiroshi

    2003-05-01

    In order to compare the irradiation effects of different ions, wandering larvae were whole-body exposed or locally irradiated with 50-MeV {sup 4}He{sup 2+}, 220-MeV {sup 12}C{sup 5+}, and 350-MeV {sup 20}Ne{sup 8+} ions, respectively. For the whole-body-exposed individuals, the survival rates at the cocooning, pupation, and emergence stages all decreased as dose increased, and a range-dependent difference was clearly observed. For local irradiation of ovaries, irradiation effects depend very strongly on the projectile range. In the case of local irradiation of dermal cells by different track sections of heavy ions, the closer the target was to the high-LET section of the track, the more pronounced were the radiation effects. These results indicated that by selectively using ion species and adjusting the irradiation depth to the target, heavy-ion radiosurgery on particular tissues or organs of small experimental animals can be performed more accurately.

  9. Beam profile measurement with CR-39 track detector for low-energy ions

    CERN Document Server

    Sato, F; Tanaka, T; Iida, T; Yamauchi, T; Oda, K

    1999-01-01

    A CR-39 track detector was successfully used to measure the outline of thin low-energy ion beams. After the etching, the surface of the detector was examined with an observation system composed of a Normarski microscope, a CCD camera and a digital image processing computer. Beam images obtained with the system were in good agreement on the outline of the beam formed with a beam aperture. Also, the resolving power in the beam outline measurement was roughly explained from the consideration of the ion range and the etch-pit growth in the chemical etching for the CR-39 detector.

  10. Interaction mean free path measurements for relativistic heavy ion fragments using CR39 plastic track detectors

    International Nuclear Information System (INIS)

    Drechsel, H.; Brechtmann, C.; Dreute, J.; Sonntag, S.; Trakowski, W.; Beer, J.; Heinrich, W.

    1984-01-01

    This paper describes an experiment measuring the interaction mean free paths for charge changing nuclear collisions of relativistic heavy ion fragments. We use a stack of CR39 plastic nuclear track detectors that was irradiated with 1.8 GeV/nucleon 40 Ar ions at the Berkeley Bevalac. About 1.5 x 10 7 etch cones were measured in this experiment using an automatic measuring system. By tracing the etch cones over successive plastic foils the particle trajectories in the stack were reconstructed. For 14185 trajectories with 6444 nuclear collisions of fragments with charge 9-15 the interaction mean free path in the plastic was determined. (orig.)

  11. State-of-health monitoring of lithium-ion battery modules and packs via incremental capacity peak tracking

    International Nuclear Information System (INIS)

    Weng, Caihao; Feng, Xuning; Sun, Jing; Peng, Huei

    2016-01-01

    Highlights: • A new framework based on ICA is used to monitor SOH on-board for battery packs. • The applicability of the framework is validated through simulation and experiment. • The method can monitor SOH for pack consisting of cells with various aging paths. • On-board incremental capacity analysis is realized by support vector regression. - Abstract: Incremental capacity analysis (ICA) is a widely used technique for lithium-ion battery state-of-health (SOH) evaluation. The effectiveness and robustness of ICA for single cell diagnostics have been reported in many published work. In this study, we extend the ICA based SOH monitoring approach from single cells to battery modules, which consist of battery cells with various aging conditions. In order to achieve on-board implementation, an IC peak tracking approach based on the ICA principles is proposed. Analytical, numerical and experimental results are presented to demonstrate the utility of the IC peak tracking framework on multi-cell battery SOH monitoring and the effects of cell non-uniformity on the proposed method. Results show that the methods developed for single cell capacity estimation can also be used for a module or pack that has parallel-connected cells.

  12. A Single Unexpected Change in Target- but Not Distractor Motion Impairs Multiple Object Tracking

    Directory of Open Access Journals (Sweden)

    Hauke S. Meyerhoff

    2013-02-01

    Full Text Available Recent research addresses the question whether motion information of multiple objects contributes to maintaining a selection of objects across a period of motion. Here, we investigate whether target and/or distractor motion information is used during attentive tracking. We asked participants to track four objects and changed either the motion direction of targets, the motion direction of distractors, neither, or both during a brief flash in the middle of a tracking interval. We observed that a single direction change of targets is sufficient to impair tracking performance. In contrast, changing the motion direction of distractors had no effect on performance. This indicates that target- but not distractor motion information is evaluated during tracking.

  13. Single ion impact detection and scanning probe aligned ion implantation for quantum bit formation

    International Nuclear Information System (INIS)

    Weis, Christoph D.

    2011-01-01

    Quantum computing and quantum information processing is a promising path to replace classical information processing via conventional computers which are approaching fundamental physical limits. Instead of classical bits, quantum bits (qubits) are utilized for computing operations. Due to quantum mechanical phenomena such as superposition and entanglement, a completely different way of information processing is achieved, enabling enhanced performance for certain problem sets. Various proposals exist on how to realize a quantum bit. Among them are electron or nuclear spins of defect centers in solid state systems. Two such candidates with spin degree of freedom are single donor atoms in silicon and nitrogen vacancy (NV) defect centers in diamond. Both qubit candidates possess extraordinary qualities which makes them promising building blocks. Besides certain advantages, the qubits share the necessity to be placed precisely in their host materials and device structures. A commonly used method is to introduce the donor atoms into the substrate materials via ion implantation. For this, focused ion beam systems can be used, or collimation techniques as in this work. A broad ion beam hits the back of a scanning probe microscope (SPM) cantilever with incorporated apertures. The high resolution imaging capabilities of the SPM allows the non destructive location of device areas and the alignment of the cantilever and thus collimated ion beam spot to the desired implant locations. In this work, this technique is explored, applied and pushed forward to meet necessary precision requirements. The alignment of the ion beam to surface features, which are sensitive to ion impacts and thus act as detectors, is demonstrated. The technique is also used to create NV center arrays in diamond substrates. Further, single ion impacts into silicon device structures are detected which enables deliberate single ion doping.

  14. Single ion impact detection and scanning probe aligned ion implantation for quantum bit formation

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Christoph D.

    2011-10-04

    Quantum computing and quantum information processing is a promising path to replace classical information processing via conventional computers which are approaching fundamental physical limits. Instead of classical bits, quantum bits (qubits) are utilized for computing operations. Due to quantum mechanical phenomena such as superposition and entanglement, a completely different way of information processing is achieved, enabling enhanced performance for certain problem sets. Various proposals exist on how to realize a quantum bit. Among them are electron or nuclear spins of defect centers in solid state systems. Two such candidates with spin degree of freedom are single donor atoms in silicon and nitrogen vacancy (NV) defect centers in diamond. Both qubit candidates possess extraordinary qualities which makes them promising building blocks. Besides certain advantages, the qubits share the necessity to be placed precisely in their host materials and device structures. A commonly used method is to introduce the donor atoms into the substrate materials via ion implantation. For this, focused ion beam systems can be used, or collimation techniques as in this work. A broad ion beam hits the back of a scanning probe microscope (SPM) cantilever with incorporated apertures. The high resolution imaging capabilities of the SPM allows the non destructive location of device areas and the alignment of the cantilever and thus collimated ion beam spot to the desired implant locations. In this work, this technique is explored, applied and pushed forward to meet necessary precision requirements. The alignment of the ion beam to surface features, which are sensitive to ion impacts and thus act as detectors, is demonstrated. The technique is also used to create NV center arrays in diamond substrates. Further, single ion impacts into silicon device structures are detected which enables deliberate single ion doping.

  15. Fluorescent detection of single tracks of alpha particles using lithium fluoride crystals

    International Nuclear Information System (INIS)

    Bilski, P.; Marczewska, B.

    2017-01-01

    Lithium fluoride single crystals were successfully used for fluorescent imaging of single tracks of alpha particles. This was realized with a standard wide-field fluorescent microscope equipped with a 100× objective. Alpha particles create F_2 and F_3"+ color centers in LiF crystals. The subsequent illumination with the blue light (wavelength around 445 nm), excites these centers and produces fluorescence with a broad band peaked at 670 nm. The observed tracks of alpha particles have diameter of about 500 nm. Focusing of the microscope at different depths in a LiF crystal, enables imaging changes of shape and position of tracks, allowing for visualization of their paths. These encouraging results are the first step towards practical application of LiF as fluorescent nuclear track detectors.

  16. Investigation of Nuclear Fragmentation in Relativistic Heavy Ion Collisions Using Plastic - Nuclear - Track Detectors

    CERN Multimedia

    2002-01-01

    In this experiment CR39 plastic nuclear track detectors will be used which are sensitive to detect relativistic nuclear fragments with charges Z@$>$5. They will be analyzed using an automatic track measuring system which was developed at the University of Siegen.\\\\ \\\\ This allows to measure large quantities of tracks in these passive detectors and to perform high statistics experiments. We intend to measure cross sections for the production of nuclear fragments from heavy ion beams at the SPS. \\\\ \\\\ The energy independence of the cross sections predicted by the idea of limiting fragmentation will be tested at high energies. In exposures with different targets we plan to analyze the factorization of the fragmentation cross sections into a target depending factor and a factor depending on the beam particle and the fragment. The cross sections for one proton remov Coulomb dissociation. \\\\ \\\\ We plan to investigate Coulomb dissociation for different targets and different energies. Fragment and projectile charges ...

  17. Convolutional Deep Belief Networks for Single-Cell/Object Tracking in Computational Biology and Computer Vision

    OpenAIRE

    Zhong, Bineng; Pan, Shengnan; Zhang, Hongbo; Wang, Tian; Du, Jixiang; Chen, Duansheng; Cao, Liujuan

    2016-01-01

    In this paper, we propose deep architecture to dynamically learn the most discriminative features from data for both single-cell and object tracking in computational biology and computer vision. Firstly, the discriminative features are automatically learned via a convolutional deep belief network (CDBN). Secondly, we design a simple yet effective method to transfer features learned from CDBNs on the source tasks for generic purpose to the object tracking tasks using only limited amount of tra...

  18. Resonator QED experiments with single 40Ca+ ions

    International Nuclear Information System (INIS)

    Lange, B.

    2006-01-01

    Combining an optical resonator with an ion trap provides the possibility for QED experiments with single or few particles interacting with a single mode of the electro-magnetic field (Cavity-QED). In the present setup, fluctuations in the count rate on a time scale below 30 seconds were purely determined by the photon statistics due to finite emission and detection efficiency, whereas a marginal drift of the system was noticeable above 200 seconds. To find methods to increase the efficiency of the photon source, investigations were conducted and experimental improvements of the setup implemented in the frame of this thesis. Damping of the resonator field and coupling of ion and field were considered as the most important factors. To reduce the damping of the resonator field, a resonator with a smaller transmissivity of the output mirror was set up. The linear trap used in the experiment allows for the interaction of multiple ions with the resonator field, so that more than one photon may be emitted per pump pulse. This was investigated in this thesis with two ions coupled to the resonator. The cross correlation of the emitted photons was measured with the Hanbury Brown-Twiss method. (orig.)

  19. Coating and functionalization of high density ion track structures by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mättö, Laura [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland); Szilágyi, Imre M., E-mail: imre.szilagyi@mail.bme.hu [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, Budapest H-1111 (Hungary); MTA-BME Technical Analytical Research Group, Szent Gellért tér 4, Budapest H-1111 (Hungary); Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014 (Finland); Laitinen, Mikko [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland); Ritala, Mikko; Leskelä, Markku [Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014 (Finland); Sajavaara, Timo [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland)

    2016-10-01

    In this study flexible TiO{sub 2} coated porous Kapton membranes are presented having electron multiplication properties. 800 nm crossing pores were fabricated into 50 μm thick Kapton membranes using ion track technology and chemical etching. Consecutively, 50 nm TiO{sub 2} films were deposited into the pores of the Kapton membranes by atomic layer deposition using Ti({sup i}OPr){sub 4} and water as precursors at 250 °C. The TiO{sub 2} films and coated membranes were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray reflectometry (XRR). Au metal electrode fabrication onto both sides of the coated foils was achieved by electron beam evaporation. The electron multipliers were obtained by joining two coated membranes separated by a conductive spacer. The results show that electron multiplication can be achieved using ALD-coated flexible ion track polymer foils. - Highlights: • Porous Kapton membranes were obtained by ion track technology and chemical etching. • TiO{sub 2} films were deposited by ALD into the pores of the Kapton membranes. • TiO{sub 2} nanotube array was prepared by removing the polymer core. • MCP structures were obtained from the coated membranes. • Electron multiplication was achieved using the ALD-coated Kapton foils.

  20. Applications of heavy ion microprobe for single event effects analysis

    International Nuclear Information System (INIS)

    Reed, Robert A.; Vizkelethy, Gyorgy; Pellish, Jonathan A.; Sierawski, Brian; Warren, Kevin M.; Porter, Mark; Wilkinson, Jeff; Marshall, Paul W.; Niu, Guofu; Cressler, John D.; Schrimpf, Ronald D.; Tipton, Alan; Weller, Robert A.

    2007-01-01

    The motion of ionizing-radiation-induced rogue charge carriers in a semiconductor can create unwanted voltage and current conditions within a microelectronic circuit. If sufficient unwanted charge or current occurs on a sensitive node, a variety of single event effects (SEEs) can occur with consequences ranging from trivial to catastrophic. This paper describes the application of heavy ion microprobes to assist with calibration and validation of SEE modeling approaches

  1. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Dietmar, E-mail: fink@xanum.uam.mx [Nuclear Physics Institute, 25068 Řež (Czech Republic); Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Vacik, Jiri; Hnatowicz, V. [Nuclear Physics Institute, 25068 Řež (Czech Republic); Muñoz Hernandez, G. [Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Garcia Arrelano, H. [Departamento de Ciencias Ambientales, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Lerma, Av. de las Garzas No. 10, Col. El Panteón, Lerma de Villada, Municipio de Lerma, Estado de México CP 52005 (Mexico); Alfonta, Lital [Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel); Kiv, Arik [Department of Materials Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel)

    2017-05-01

    Highlights: • Application of swift heavy ion tracks in biosensing. • Obtaining yet unknown diffusion coefficients of organic matter across etched ion tracks. • Obtaining diffusion coefficients of organics in etched ion tracks of biosensors. • Comparison with Renkin’s equation to predict the effective etched track diameter in the given experiments. - Abstract: For understanding of the diffusion kinetics and their optimization in swift heavy ion track-based biosensors, recently a diffusion simulation was performed. This simulation aimed at yielding the degree of enrichment of the enzymatic reaction products in the highly confined space of the etched ion tracks. A bunch of curves was obtained for the description of such sensors that depend only on the ratio of the diffusion coefficient of the products to that of the analyte within the tracks. As hitherto none of these two diffusion coefficients is accurately known, the present work was undertaken. The results of this paper allow one to quantify the previous simulation and hence yield realistic predictions of glucose-based biosensors. At this occasion, also the influence of the etched track radius on the diffusion coefficients was measured and compared with earlier prediction.

  2. Conduction Mechanisms and Structure of Ionomeric Single-Ion Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Colby, Ralph H. [Pennsylvania State Univ., University Park, PA (United States); Maranas, Janna K. [Pennsylvania State Univ., University Park, PA (United States); Mueller, Karl T. [Pennsylvania State Univ., University Park, PA (United States); Runt, James [Pennsylvania State Univ., University Park, PA (United States); Winey, Karen I. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    2015-03-01

    Our team has designed using DFT (Gaussian) and synthesized low glass transition temperature single-ion conductors that are either polyanions that conduct small cations Li+, Na+, Cs+ or polycations that conduct small anions F-, OH-, Br-. We utilize a wide range of complimentary experimental materials characterization tools to understand ion transport; differential scanning calorimetry, dielectric relaxation spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, linear viscoelasticity, X-ray scattering and molecular dynamics simulations. The glass transition temperature Tg needs to be as low as possible to facilitate ion transport, so the nonionic parts of the polymer need to be polar, flexible and have strong solvation interactions with the ions. The lowest Tg we have managed for polyanions conducting Li+ is -60 °C. In contrast, polysiloxanes with PEO side chains and tetrabutylphosphonium cationic side groups have Tg ≈ -75 °C that barely increases with ion content, as anticipated by DFT. A survey of all polyanions in the literature suggests that Tg < -80 °C is needed to achieve the 10-4 S/cm conductivity needed for battery separators.

  3. Single trapped cold ions: a testing ground for quantum mechanics

    International Nuclear Information System (INIS)

    Maniscalco, S

    2005-01-01

    In this article I review some results obtained during my PhD work in the group of Professor Messina, at the University of Palermo. I discuss some proposals aimed at exploring fundamental issues of quantum theory, e.g. entanglement and quantum superpositions, in the context of single trapped ions. This physical context turns out to be extremely well suited both for studying fundamental features of quantum mechanics, such as the quantum-classical border, and for technological applications such as quantum logic gates and quantum registers. I focus on some procedures for engineering nonclassical states of the vibrational motion of the centre of mass of the ion. I consider both the case in which the ion interacts with classical laser beams and the case of interaction with a quantized mode of light. In particular, I discuss the generation of Schroedinger cat-like states, Bell states and Greenberger-Horn-Zeilinger states. The schemes for generating nonclassical states stem from two different quantum processes: the parity effect and the quantum state manipulation via quantum non-demolition measurement. Finally, I consider a microscopic theory of the interaction of a quantum harmonic oscillator (the centre of mass of the ion in the trapped ion context) with a bosonic thermal environment. Using an exact approach to the dynamics, I discuss a quantum theory of heating of trapped ions able to describe both the short time non-Markovian regime and the thermalization process. I conclude showing briefly how the trapped ion systems can be used as simulators of key models of open quantum systems such as the Caldeira-Leggett model. (phd tutorial)

  4. Diffracted X-ray tracking: new system for single molecular detection with X-rays

    CERN Document Server

    Sasaki, Y C; Adachi, S; Suzuki, Y; Yagi, N

    2001-01-01

    We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements.

  5. Diffracted X-ray tracking: new system for single molecular detection with X-rays

    International Nuclear Information System (INIS)

    Sasaki, Y.C.; Okumura, Y.; Adachi, S.; Suzuki, Y.; Yagi, N.

    2001-01-01

    We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements

  6. Optical performance of inclined south-north single-axis tracked solar panels

    International Nuclear Information System (INIS)

    Li, Zhimin; Liu, Xinyue; Tang, Runsheng

    2010-01-01

    To investigate optical performance of the inclined south-north single-axis (ISN-axis, in short) tracked solar panels, a mathematical procedure to estimate the annual collectible radiation on fixed and tracked panels was suggested based on solar geometry and monthly horizontal radiation. For solar panels tracking about ISN-axis, the yearly optimal tilt-angle of ISN-axis for maximizing annual solar gain was about 3 o deviating from the site latitude in most of China except in areas with poor solar resources, and the maximum annual collectible radiation on ISN-axis tracked panels was about 97-98% of that on dual-axis tracked panels; whereas for ISN-axis tracked panels with the tilt-angle of ISN-axis being adjusted four times in a year at three fixed tilt-angles, the annual collectible radiation was almost close to that on dual-axis tracked panels, the optimum date of tilt-angle adjustment of ISN-axis was 23 days from the equinoxes, and the optimum tilt-angle adjustment value for each adjustment was about 22 o . Compared to fixed south-facing solar panels inclined at an optimal tilt-angle, the increase in the annual solar gain due to using ISN-axis sun tracking was above 30% in the areas with abundant solar resources and less than 20% in the areas with poor solar resources.

  7. Elastic (stress-strain) halo associated with ion-induced nano-tracks in lithium niobate: role of crystal anisotropy

    International Nuclear Information System (INIS)

    Rivera, A; Garcia, G; Olivares, J; Crespillo, M L; Agulló-López, F

    2011-01-01

    The elastic strain/stress fields (halo) around a compressed amorphous nano-track (core) caused by a single high-energy ion impact on LiNbO 3 are calculated. A method is developed to approximately account for the effects of crystal anisotropy of LiNbO 3 (symmetry 3m) on the stress fields for tracks oriented along the crystal axes (X, Y or Z). It only considers the zero-order (axial) harmonic contribution to the displacement field in the perpendicular plane and uses effective Poisson moduli for each particular orientation. The anisotropy is relatively small; however, it accounts for some differential features obtained for irradiations along the crystallographic axes X, Y and Z. In particular, the irradiation-induced disorder (including halo) and the associated surface swelling appear to be higher for irradiations along the X- or Y-axis in comparison with those along the Z-axis. Other irradiation effects can be explained by the model, e.g. fracture patterns or the morphology of pores after chemical etching of tracks. Moreover, it offers interesting predictions on the effect of irradiation on lattice parameters.

  8. Conductivity enhancement of ion tracks in tetrahedral amorphous carbon by doping with N, B, Cu and Fe

    International Nuclear Information System (INIS)

    Krauser, J.; Nix, A.-K.; Gehrke, H.-G.; Hofsäss, H.; Trautmann, C.; Weidinger, A.

    2012-01-01

    Conducting ion tracks are formed when high-energy heavy ions (e.g. 1 GeV Au) pass through tetrahedral amorphous carbon (ta-C). These nanowires with a diameter of about 8 nm are embedded in the insulating ta-C matrix and of interest for various nanotechnological applications. Usually the overall conductivity of the tracks and the current/voltage characteristics (Ohmic or non-Ohmic) vary strongly from track to track, even when measured on the same sample, indicating that the track formation is neither complete nor homogeneous. To improve the track conductivity, doping of ta-C with N, B, Cu, or Fe is investigated. Beneficial changes in track conductivity after doping compete with a conductivity increase of the surrounding matrix material. Best results are achieved by incorporation of 1 at.% Cu, while for different reasons, the improvement of the tracks remains moderate for N, B, and Fe doping. Conductivity enhancement of the tracks is assumed to develop during the ion track formation process by an increased number of localized states which contribute to the current transport.

  9. Characterization of Eag1 channel lateral mobility in rat hippocampal cultures by single-particle-tracking with quantum dots.

    Directory of Open Access Journals (Sweden)

    David Gómez-Varela

    2010-01-01

    Full Text Available Voltage-gated ion channels are main players involved in fast synaptic events. However, only slow intracellular mechanisms have so far been described for controlling their localization as real-time visualization of endogenous voltage-gated channels at high temporal and spatial resolution has not been achieved yet. Using a specific extracellular antibody and quantum dots we reveal and characterize lateral mobility as a faster mechanism to dynamically control the number of endogenous ether-a-go-go (Eag1 ion channels inside synapses. We visualize Eag1 entering and leaving synapses by lateral diffusion in the plasma membrane of rat hippocampal neurons. Mathematical analysis of their trajectories revealed how the motion of Eag1 gets restricted when the channels diffuse into the synapse, suggesting molecular interactions between Eag1 and synaptic components. In contrast, Eag1 channels switch to Brownian movement when they exit synapses and diffuse into extrasynaptic membranes. Furthermore, we demonstrate that the mobility of Eag1 channels is specifically regulated inside synapses by actin filaments, microtubules and electrical activity. In summary, using single-particle-tracking techniques with quantum dots nanocrystals, our study shows for the first time the lateral diffusion of an endogenous voltage-gated ion channel in neurons. The location-dependent constraints imposed by cytoskeletal elements together with the regulatory role of electrical activity strongly suggest a pivotal role for the mobility of voltage-gated ion channels in synaptic activity.

  10. Applications of CR-39 solid state nuclear track detector to ion beam diagnosis

    International Nuclear Information System (INIS)

    Kanasaki, Masato; Hattori, Atsuto; Oda, Keiji; Yamauchi, Tomoya; Fukuda, Yuji; Sakaki, Hironao; Nishiuchi, Mamiko; Kondo, Kiminori; Kurashima, Satoshi; Kamiya, Tomihiro

    2012-01-01

    CR-39 solid state nuclear track detector, which was developed for optical lens, has been applied for various field such as radon surveys, measurement of galactic cosmic ray, cell irradiation experiment and so on. The CR-39 detectors have the great advantages of being insensitive to high energy photons and electrons and capable of detecting only ions in the mixed fields such as laser driven relativistic plasmas. Though there are some analytical methods of CR-39 to diagnose ion beam, unfortunately, only few researchers in the field of plasma know the methods. This article looks at how to use CR-39 detectors and introduce the accomplishment of the joint study JAEA and Kobe Univ. for application of CR-39 detectors to ion beam diagnosis. (author)

  11. Single-Track Melt-Pool Measurements and Microstructures in Inconel 625

    Science.gov (United States)

    Ghosh, Supriyo; Ma, Li; Levine, Lyle E.; Ricker, Richard E.; Stoudt, Mark R.; Heigel, Jarred C.; Guyer, Jonathan E.

    2018-02-01

    We use single-track laser melting experiments and simulations on Inconel 625 to estimate the dimensions and microstructure of the resulting melt pool. Our work is based on a design-of-experiments approach which uses multiple laser power and scan speed combinations. Single-track experiments generated melt pools of certain dimensions that showed reasonable agreement with our finite-element calculations. Phase-field simulations were used to predict the size and segregation of the cellular microstructure that formed along the melt-pool boundaries for the solidification conditions that changed as a function of melt-pool dimensions.

  12. Single-Track Melt-Pool Measurements and Microstructures in Inconel 625

    Science.gov (United States)

    Ghosh, Supriyo; Ma, Li; Levine, Lyle E.; Ricker, Richard E.; Stoudt, Mark R.; Heigel, Jarred C.; Guyer, Jonathan E.

    2018-06-01

    We use single-track laser melting experiments and simulations on Inconel 625 to estimate the dimensions and microstructure of the resulting melt pool. Our work is based on a design-of-experiments approach which uses multiple laser power and scan speed combinations. Single-track experiments generated melt pools of certain dimensions that showed reasonable agreement with our finite-element calculations. Phase-field simulations were used to predict the size and segregation of the cellular microstructure that formed along the melt-pool boundaries for the solidification conditions that changed as a function of melt-pool dimensions.

  13. Design of a single ion facility and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Cholewa, M.; Saint, A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    The use of micro-irradiation techniques in radiobiology is not new; however, the current techniques take advantage of recent developments in particle delivery, focussing detection, image processing, cell recognition and computer control. These developments have generally come from other fields, for example microbeam elemental analysis techniques and single-event upset testing of semiconductor devices. Also in radiation biology there have been important advances in developments of individual cell assays, which allow a wide range of endpoints to be studied with good accuracy at low doses. Many of the studies that are planned involve following the responses of individual cells after a programmed exposure to charged-particle traversals. To probe the radiation sensitivity of a single cell and/or its constituents with a submicron resolution several developments are needed. The essential parameters of the proposed system can be summarised as follows: a focussed beam of ions of 300nm or less at the cell; a reliable (close to 100%) single ion detection; a fast beam switch to prevent second hits; a target holder adapted for the irradiation of wet cells and a fully automated system for cell recognition and single hits. 1 fig.

  14. Design of a single ion facility and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Cholewa, M; Saint, A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    The use of micro-irradiation techniques in radiobiology is not new; however, the current techniques take advantage of recent developments in particle delivery, focussing detection, image processing, cell recognition and computer control. These developments have generally come from other fields, for example microbeam elemental analysis techniques and single-event upset testing of semiconductor devices. Also in radiation biology there have been important advances in developments of individual cell assays, which allow a wide range of endpoints to be studied with good accuracy at low doses. Many of the studies that are planned involve following the responses of individual cells after a programmed exposure to charged-particle traversals. To probe the radiation sensitivity of a single cell and/or its constituents with a submicron resolution several developments are needed. The essential parameters of the proposed system can be summarised as follows: a focussed beam of ions of 300nm or less at the cell; a reliable (close to 100%) single ion detection; a fast beam switch to prevent second hits; a target holder adapted for the irradiation of wet cells and a fully automated system for cell recognition and single hits. 1 fig.

  15. Microdosimetry for a carbon ion beam using track-etched detectors

    International Nuclear Information System (INIS)

    Ambrozova, I.; Ploc, O.; Davidkova, M.; Vondracek, V.; Sefl, M.; Stepan, V.; Pachnerova Brabcova, K.; Incerti, S.

    2015-01-01

    Track-etched detectors (TED) have been used as linear energy transfer (LET) spectrometers in heavy ion beams for many years. LET spectra and depth -dose distribution of a carbon ion beam were measured behind polymethylmethacrylate degraders at Heavy Ion Medical Accelerator in Chiba, Japan. The measurements were performed along monoenergetic beam with energy 290 MeV u -1 in different positions: (1) at beam extraction area, (2) at beginning, (3) maximum and (4) behind the Bragg peak region (0, 117, 147 and 151 mm of water-equivalent depth, respectively). The LET spectra inside and outside of the primary ion beam have been evaluated. TED record only heavy charged particles with LET above 8 -10 keV μm -1 , while electrons and ions with lower LET are not detected. The Geant4 simulation toolkit version 4.9.6.P01 has been used to estimate the contribution of non-detected particles to absorbed dose. Presented results demonstrate the applicability of TED for microdosimetry measurements in therapeutic carbon ion beams. (authors)

  16. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    International Nuclear Information System (INIS)

    Wang Ting; Li Fanghua; Liu Qingfang; Bian Po; Wang Jufang; Wu Yuejin; Wu Lijun; Li Wenjian

    2012-01-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and γ-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  17. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ting [University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026 (China); Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Fanghua [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Liu Qingfang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Bian Po, E-mail: bianpo@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Wang Jufang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Wu Yuejin; Wu Lijun [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Wenjian [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China)

    2012-09-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and {gamma}-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  18. Investigation of radial dose effect on single event upset cross-section due to heavy ions using GEANT4

    International Nuclear Information System (INIS)

    Boorboor, S.; Feghhi, S.A.H.; Jafari, H.

    2015-01-01

    The heavy ions are the main cause to produce single event upset (SEU) damage on electronic devices since they are high LET radiations. The dimension of electronic components in new technology, arise a challenge in radiation effect estimations. Accurate investigations require fully considering the ion track in energy deposition as a radial dose distribution. In this work, the distribution of delta rays as well as LET have been calculated to determine ionization structure around ion track by a Monte Carlo code, GEANT4. The radial dose of several heavy ions with different energy in silicon was investigated and compared with the works by other authors in this field. The results showed that heavy ions with identical LET can have different SEU cross-section in silicon transistors. As a demonstrative example, according to our results, the error probability for 4.8 GeV iron was 8 times greater than that for 15 MeV carbon ions, in transistors with new process technology which have small dimension and low critical charges. Our results show that considering radial dose distribution considerably improves the accuracy of the SEU cross-section estimation in electronic devices especially for new technologies. - Highlights: • The single event upset is produced by heavy ions interaction on electronic devices. • The radial dose of several heavy ions in silicon was calculated by GEANT4. • Heavy ions with identical LET had different SEU cross-section in silicon transistors. • Low dimension and critical charge devices were more sensitive to radial dose effect

  19. 4-D single particle tracking of synthetic and proteinaceous microspheres reveals preferential movement of nuclear particles along chromatin - poor tracks.

    Science.gov (United States)

    Bacher, Christian P; Reichenzeller, Michaela; Athale, Chaitanya; Herrmann, Harald; Eils, Roland

    2004-11-23

    The dynamics of nuclear organization, nuclear bodies and RNPs in particular has been the focus of many studies. To understand their function, knowledge of their spatial nuclear position and temporal translocation is essential. Typically, such studies generate a wealth of data that require novel methods in image analysis and computational tools to quantitatively track particle movement on the background of moving cells and shape changing nuclei. We developed a novel 4-D image processing platform (TIKAL) for the work with laser scanning and wide field microscopes. TIKAL provides a registration software for correcting global movements and local deformations of cells as well as 2-D and 3-D tracking software. With this new tool, we studied the dynamics of two different types of nuclear particles, namely nuclear bodies made from GFP-NLS-vimentin and microinjected 0.1 mum - wide polystyrene beads, by live cell time-lapse microscopy combined with single particle tracking and mobility analysis. We now provide a tool for the automatic 3-D analysis of particle movement in parallel with the acquisition of chromatin density data. Kinetic analysis revealed 4 modes of movement: confined obstructed, normal diffusion and directed motion. Particle tracking on the background of stained chromatin revealed that particle movement is directly related to local reorganization of chromatin. Further a direct comparison of particle movement in the nucleoplasm and the cytoplasm exhibited an entirely different kinetic behaviour of vimentin particles in both compartments. The kinetics of nuclear particles were slightly affected by depletion of ATP and significantly disturbed by disruption of actin and microtubule networks. Moreover, the hydration state of the nucleus had a strong impact on the mobility of nuclear bodies since both normal diffusion and directed motion were entirely abolished when cells were challenged with 0.6 M sorbitol. This effect correlated with the compaction of chromatin

  20. Ion implantation of CdTe single crystals

    International Nuclear Information System (INIS)

    Wiecek, Tomasz; Popovich, Volodymir; Bester, Mariusz; Kuzma, Marian

    2017-01-01

    Ion implantation is a technique which is widely used in industry for unique modification of metal surface for medical applications. In semiconductor silicon technology ion implantation is also widely used for thin layer electronic or optoelectronic devices production. For other semiconductor materials this technique is still at an early stage. In this paper based on literature data we present the main features of the implantation of CdTe single crystals as well as some of the major problems which are likely to occur when dealing with them. The most unexpected feature is the high resistance of these crystals against the amorphization caused by ion implantation even at high doses (10"1"7 1/cm"2). The second property is the disposal of defects much deeper in the sample then it follows from the modeling calculations. The outline of principles of the ion implantation is included in the paper. The data based on RBS measurements and modeling results obtained by using SRIM software were taken into account.

  1. Plasma immersion ion implantation: duplex layers from a single process

    International Nuclear Information System (INIS)

    Hutchings, R.; Collins, G.A.; Tendys, J.

    1992-01-01

    Plasma immersion ion implantation (PI 3 ) is an alternative non-line-of-sight technique for implanting ions directly from a plasma which surrounds the component to be treated. In contrast to plasma source ion implantation, the PI 3 system uses an inductively coupled r.f. plasma. It is shown that nitrogen can be retained during implantation at elevated temperatures, even for unalloyed steels. This allows controlled diffusion of nitrogen to greater depths, thereby improving the load bearing capacity of the implanted layer. Components can be heated directly, using the energy deposited by the incident ions during the pulsed implantation. The necessary temperature control can be accomplished simply by regulating the frequency and length of the high voltage pulses applied to the component. Chemical depth profiles and microstructural data obtained from H13 tool steel are used to show that PI 3 can, in a single process, effectively produce a duplex subsurface structure. This structure consists of an outer non-equilibrium layer typical of nitrogen implantation (containing in excess of 20 at.% nitrogen) backed by a substantial diffusion zone of much lower nitrogen content. The relationship between implantation temperature and the resultant subsurface microstructure is explored. (orig.)

  2. Surfactant-controlled etching of ion track nanopores and its practical applications in membrane technology

    International Nuclear Information System (INIS)

    Apel, P.Yu.; Blonskaya, I.V.; Dmitriev, S.N.; Mamonova, T.I.; Orelovitch, O.L.; Sartowska, B.; Yamauchi, Yu.

    2008-01-01

    The effect of surfactants on chemical development of ion tracks in polymers has been studied. It has been shown that surface-active agents added to an alkaline etching solution adsorb on the polymer surface at the pore entrances. This reduces the etch rate, which leads to the formation of pores tapered toward the surface. Self-assembly of surfactant molecules at the pore entrance creates a barrier for their penetration into the etched-out nanopores, whereas hydroxide ions diffuse freely. Due to this, the internal pore volume grows faster than the pore surface diameter. The ability to control pore shape is demonstrated with the fabrication of profiled nano- and micropores in polyethylene terephthalate, polycarbonate. Some earlier published data on small track-etched pores in polycarbonate (in particular, the pore diameter vs. etching time curves measured conductometrically) have been revised in light of the above findings. Adding surfactants to chemical etchants makes it possible to optimize the structure of track membranes, thus improving their retention and permeation properties. Asymmetric membranes with thin skin retention layers have been produced and their performance studied

  3. Relation between track structure and LET effect on free radical formation for ion beam-irradiated alanine dosimeter

    International Nuclear Information System (INIS)

    Krushev, V.V.; Koizumi, Hitoshi; Ichikawa, Tsuneki; Yoshida, Hiroshi; Shibata, Hiromi; Tagawa, Seiichi; Yoshida, Yoichi

    1994-01-01

    The yield and local concentration of free radicals generated from alanine (α-aminopropionic acid) by irradiation with 3 MeV H + and He + ions were examined by means of electron spin resonance (ESR) and ESR power saturation methods at room temperature. The G-value of the radical formation showed a marked dependence on linear energy transfer (LET) of the ions. The G-value for the H + ion (average LET: 28 eV/nm) was almost the same as that for γ-irradiation and it was smaller by a factor of 1/4.7 for the He + ion (average LET: 225eV/nm). Combining the local concentration of the free radicals along the ion tracks with the G-values and the reported ion range, the radius of a track filled with free radicals was estimated to be 4 ∼ 5 nm by assuming a simple rod-shaped track with a constant radius and homogeneous distribution of the free radicals in it. The track radius scarcely depends on the LET within the range examined. The radiation energy deposited in the core region of the ion track was concluded to spread over the rod to generate free radicals. (author)

  4. Targeting neurotransmitter receptors with nanoparticles in vivo allows single-molecule tracking in acute brain slices

    Science.gov (United States)

    Varela, Juan A.; Dupuis, Julien P.; Etchepare, Laetitia; Espana, Agnès; Cognet, Laurent; Groc, Laurent

    2016-03-01

    Single-molecule imaging has changed the way we understand many biological mechanisms, particularly in neurobiology, by shedding light on intricate molecular events down to the nanoscale. However, current single-molecule studies in neuroscience have been limited to cultured neurons or organotypic slices, leaving as an open question the existence of fast receptor diffusion in intact brain tissue. Here, for the first time, we targeted dopamine receptors in vivo with functionalized quantum dots and were able to perform single-molecule tracking in acute rat brain slices. We propose a novel delocalized and non-inflammatory way of delivering nanoparticles (NPs) in vivo to the brain, which allowed us to label and track genetically engineered surface dopamine receptors in neocortical neurons, revealing inherent behaviour and receptor activity regulations. We thus propose a NP-based platform for single-molecule studies in the living brain, opening new avenues of research in physiological and pathological animal models.

  5. Single quantum dot tracking reveals the impact of nanoparticle surface on intracellular state.

    Science.gov (United States)

    Zahid, Mohammad U; Ma, Liang; Lim, Sung Jun; Smith, Andrew M

    2018-05-08

    Inefficient delivery of macromolecules and nanoparticles to intracellular targets is a major bottleneck in drug delivery, genetic engineering, and molecular imaging. Here we apply live-cell single-quantum-dot imaging and tracking to analyze and classify nanoparticle states after intracellular delivery. By merging trajectory diffusion parameters with brightness measurements, multidimensional analysis reveals distinct and heterogeneous populations that are indistinguishable using single parameters alone. We derive new quantitative metrics of particle loading, cluster distribution, and vesicular release in single cells, and evaluate intracellular nanoparticles with diverse surfaces following osmotic delivery. Surface properties have a major impact on cell uptake, but little impact on the absolute cytoplasmic numbers. A key outcome is that stable zwitterionic surfaces yield uniform cytosolic behavior, ideal for imaging agents. We anticipate that this combination of quantum dots and single-particle tracking can be widely applied to design and optimize next-generation imaging probes, nanoparticle therapeutics, and biologics.

  6. Evaluating the Promise of Single-Track Year-Round Schools.

    Science.gov (United States)

    Haenn, Joseph F.

    1996-01-01

    Describes two single-track year-round elementary schools in Durham, North Carolina, established in discrete attendance zones. Remediation and enrichment activities were provided during intersession. Low-SES students were overrepresented in remediation sessions. Student outcomes data (end-of-grade reading and math test scores) suggest that…

  7. Screened ion-ion interaction in mercury-chain compounds: Single chain

    International Nuclear Information System (INIS)

    Mohan, M.M.; Griffin, A.

    1985-01-01

    At room temperature, the mercury chains in Hg/sub 3-delta/AsF 6 exhibit phonons characteristic of a one-dimensional lattice. We calculate the screening of the Hg ion-ion interaction in a single chain by electrons moving in a cylindrical potential of finite radius, within the random-phase approximation. The resulting Bohm-Staver-type expression for the phonon velocity is (Z 2 mN/sub I//MN/sub e/)/sup 1/2/v/sub F/, where Z is the Hg ionic charge and N/sub I/ (N/sub e/) is the number of ions (electrons) per unit length. Use of the Tomonaga-Luttinger solution for the electronic response function (keeping only the small-momentum scattering processes) just renormalizes the Fermi velocity in this expression

  8. Scaling of ion implanted Si:P single electron devices

    International Nuclear Information System (INIS)

    Escott, C C; Hudson, F E; Chan, V C; Petersson, K D; Clark, R G; Dzurak, A S

    2007-01-01

    We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n + ) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number

  9. Scaling of ion implanted Si:P single electron devices

    Energy Technology Data Exchange (ETDEWEB)

    Escott, C C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Hudson, F E [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Chan, V C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Petersson, K D [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Clark, R G [Centre for Quantum Computer Technology, School of Physics, UNSW, Sydney, 2052 (Australia); Dzurak, A S [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia)

    2007-06-13

    We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n{sup +}) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number.

  10. Direct tracking error characterization on a single-axis solar tracker

    International Nuclear Information System (INIS)

    Sallaberry, Fabienne; Pujol-Nadal, Ramon; Larcher, Marco; Rittmann-Frank, Mercedes Hannelore

    2015-01-01

    Highlights: • The solar tracker of a small-size parabolic trough collector was tested. • A testing procedure for the tracking error characterization of a single-axis tracker was proposed. • A statistical analysis on the tracking error distribution was done regarding different variables. • The optical losses due to the tracking error were calculated based on a ray-tracing simulation. - Abstract: The solar trackers are devices used to orientate solar concentrating systems in order to increase the focusing of the solar radiation on a receiver. A solar concentrator with a medium or high concentration ratio needs to be orientated correctly by an accurate solar tracking mechanism to avoid losing the sunrays out from the receiver. Hence, to obtain an appropriate operation, it is important to know the accuracy of a solar tracker in regard to the required precision of the concentrator in order to maximize the collector optical efficiency. A procedure for the characterization of the accuracy of a solar tracker is presented for a single-axis solar tracker. More precisely, this study focuses on the estimation of the positioning angle error of a parabolic trough collector using a direct procedure. A testing procedure, adapted from the International standard IEC 62817 for photovoltaic trackers, was defined. The results show that the angular tracking error was within ±0.4° for this tracker. The optical losses due to the tracking were calculated using the longitudinal incidence angle modifier obtained by ray-tracing simulation. The acceptance angles for various transversal angles were analyzed, and the average optical loss, due to the tracking, was 0.317% during the whole testing campaign. The procedure presented in this work showed that the tracker precision was adequate for the requirements of the analyzed optical system.

  11. Poly(vinylidene fluoride)-based ion track membranes with different pore diameters and shapes. SEM observations and conductometric analysis

    International Nuclear Information System (INIS)

    Nuryanthi, Nunung; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Enomoto, Kazuyuki; Sawada, Shin-ichi; Maekawa, Yasunari; Voss, Kay-Obbe; Trautmann, Christina; Neumann, Reinhard

    2010-01-01

    Poly(vinylidene fluoride) (PVDF) membranes with conical and cylindrical nanopores were prepared in a controlled manner by the ion-track technique, which involved heavy-ion beam irradiation and subsequent alkaline etching. The etching behavior mainly depended on the energy deposition of the ion beams, and thus its depth distribution, estimated by theoretical simulation, was successfully applied to control the shapes and diameters of the etched pores. Scanning electron microscopy (SEM) and electrolytic conductometry provided an insight into the critical experimental parameters. Interestingly, applying a higher voltage to the conductometry cell promoted track etching up to breakthrough probably because electrophoretic migration of the dissolved products occurred out of each pore. (author)

  12. Synthesis of environmentally responsive organic materials by application of ion track holes in polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Omichi, Hideki; Yoshida, Masaru; Asano, Masaharu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Katakai, Ryoichi; Spohr, R; Vetter, J

    1997-03-01

    Polymer films were irradiated by heavy ion beams and etched by a concentrated alkali solution to produce particle track membranes (PTMs). Then the PTMs were chemically modified by grafting such monomers as amino acid group containing methacryloyl and N-isopropylacrylamide the polymers of which are known as environmentally responsive hydrogels. The size of pores of the modified PTMs under different temperatures in water was followed by electron microscopy. The pore was controlled from an open state to a completely closed state by changing temperature. The conductivity through the membrane was measured by changing the temperature of the cell. (author)

  13. An explosive-emitter cathode produced using the heavy ion track technique

    International Nuclear Information System (INIS)

    Akap'ev, G.N.; Korenev, S.A.

    1988-01-01

    A cathode based on thin metallic foils with a homogeneous needle surface is described. The cathode was manufactured using the heavy ion track technique which permits the production of cathodes with an unlimited area and a needle density ranging from about 10 3 to 10 9 needles per cm 2 . An electron gun using this type of cathode has a current of 200-900 A and an energy of 100-300 keV. The cross section of the electron beam is fairly uniform. It is shown that needle emitters of similar shape and size play the principal role in forming a homogeneous cathode plasma

  14. Convolutional Deep Belief Networks for Single-Cell/Object Tracking in Computational Biology and Computer Vision.

    Science.gov (United States)

    Zhong, Bineng; Pan, Shengnan; Zhang, Hongbo; Wang, Tian; Du, Jixiang; Chen, Duansheng; Cao, Liujuan

    2016-01-01

    In this paper, we propose deep architecture to dynamically learn the most discriminative features from data for both single-cell and object tracking in computational biology and computer vision. Firstly, the discriminative features are automatically learned via a convolutional deep belief network (CDBN). Secondly, we design a simple yet effective method to transfer features learned from CDBNs on the source tasks for generic purpose to the object tracking tasks using only limited amount of training data. Finally, to alleviate the tracker drifting problem caused by model updating, we jointly consider three different types of positive samples. Extensive experiments validate the robustness and effectiveness of the proposed method.

  15. Experimental investigations of single-electron detachment processes from H- ions colliding with MeV/u, highly charged ions

    International Nuclear Information System (INIS)

    Tawara, H.; Tonuma, T.; Kumagai, H.; Imai, T.; Uskov, D.B.; Presnyakov, L.P.

    1999-01-01

    Single electron detachment processes from negative hydrogen ions under collisions with MeV/u highly charged ions have been investigated using the so-called crossed-beams technique. The preliminary results of the single-electron detachment cross sections obtained is found to be in crude agreement with some empirical and theoretical estimations. (orig.)

  16. Single-ion quantum lock-in amplifier.

    Science.gov (United States)

    Kotler, Shlomi; Akerman, Nitzan; Glickman, Yinnon; Keselman, Anna; Ozeri, Roee

    2011-05-05

    Quantum metrology uses tools from quantum information science to improve measurement signal-to-noise ratios. The challenge is to increase sensitivity while reducing susceptibility to noise, tasks that are often in conflict. Lock-in measurement is a detection scheme designed to overcome this difficulty by spectrally separating signal from noise. Here we report on the implementation of a quantum analogue to the classical lock-in amplifier. All the lock-in operations--modulation, detection and mixing--are performed through the application of non-commuting quantum operators to the electronic spin state of a single, trapped Sr(+) ion. We significantly increase its sensitivity to external fields while extending phase coherence by three orders of magnitude, to more than one second. Using this technique, we measure frequency shifts with a sensitivity of 0.42 Hz Hz(-1/2) (corresponding to a magnetic field measurement sensitivity of 15 pT Hz(-1/2)), obtaining an uncertainty of less than 10 mHz (350 fT) after 3,720 seconds of averaging. These sensitivities are limited by quantum projection noise and improve on other single-spin probe technologies by two orders of magnitude. Our reported sensitivity is sufficient for the measurement of parity non-conservation, as well as the detection of the magnetic field of a single electronic spin one micrometre from an ion detector with nanometre resolution. As a first application, we perform light shift spectroscopy of a narrow optical quadrupole transition. Finally, we emphasize that the quantum lock-in technique is generic and can potentially enhance the sensitivity of any quantum sensor. ©2011 Macmillan Publishers Limited. All rights reserved

  17. Flagged uniform particle splitting for variance reduction in proton and carbon ion track-structure simulations

    Science.gov (United States)

    Ramos-Méndez, José; Schuemann, Jan; Incerti, Sebastien; Paganetti, Harald; Schulte, Reinhard; Faddegon, Bruce

    2017-08-01

    Flagged uniform particle splitting was implemented with two methods to improve the computational efficiency of Monte Carlo track structure simulations with TOPAS-nBio by enhancing the production of secondary electrons in ionization events. In method 1 the Geant4 kernel was modified. In method 2 Geant4 was not modified. In both methods a unique flag number assigned to each new split electron was inherited by its progeny, permitting reclassification of the split events as if produced by independent histories. Computational efficiency and accuracy were evaluated for simulations of 0.5-20 MeV protons and 1-20 MeV u-1 carbon ions for three endpoints: (1) mean of the ionization cluster size distribution, (2) mean number of DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) classified with DBSCAN, and (3) mean number of SSBs and DSBs classified with a geometry-based algorithm. For endpoint (1), simulation efficiency was 3 times lower when splitting electrons generated by direct ionization events of primary particles than when splitting electrons generated by the first ionization events of secondary electrons. The latter technique was selected for further investigation. The following results are for method 2, with relative efficiencies about 4.5 times lower for method 1. For endpoint (1), relative efficiency at 128 split electrons approached maximum, increasing with energy from 47.2  ±  0.2 to 66.9  ±  0.2 for protons, decreasing with energy from 51.3  ±  0.4 to 41.7  ±  0.2 for carbon. For endpoint (2), relative efficiency increased with energy, from 20.7  ±  0.1 to 50.2  ±  0.3 for protons, 15.6  ±  0.1 to 20.2  ±  0.1 for carbon. For endpoint (3) relative efficiency increased with energy, from 31.0  ±  0.2 to 58.2  ±  0.4 for protons, 23.9  ±  0.1 to 26.2  ±  0.2 for carbon. Simulation results with and without splitting agreed within 1% (2 standard

  18. The gain of single-axis tracked panel according to extraterrestrial radiation

    International Nuclear Information System (INIS)

    Chang, T.P.

    2009-01-01

    In the present study, the gain in extraterrestrial radiation received by a single-axis tracked panel relative to a fixed panel was systematically analyzed over a specific period of time. The dynamic angle that the tracked panel should rotate by in order to follow the sun was derived through a series of spherical trigonometric procedures. The instantaneous incident angle of sunlight upon the panel was then calculated, assuming that the panel would simultaneously follow the sun's position. Thus, instantaneous increments of solar energy received by the tracked panel relative to the fixed panel are originally presented. The results show that the angle the tracked panel has to rotate by is 0 deg. at solar noon, and increases towards dawn or dusk. The incident angle of sunlight upon the tracked panel is always smaller than that upon the fixed panel, except at solar noon. As for panels installed with a yearly optimal tilt angle in Taipei, the gains are between 36.3% and 62.1% for four particular days of year, between 37.8% and 60.8% for the four seasons and 49.3% over the entire year. The amount of radiation collected by the tracked panel is enhanced as the maximum rotation angle is increased. The irradiation ratio of the tracked panel to the fixed panel is close to 1.5 for latitudes below 65 deg. and gradually increases for latitudes above this. The yearly optimal tilt angle of a south-facing fixed panel is approximately equal to 0.9 multiplied by the latitude (i.e. 0.9 x φ) for latitudes below 65 deg. and is about 56 + 0.4 x (φ - 65) otherwise

  19. Effect of the track potential on the motion and energy flow of secondary electrons created from heavy-ion irradiation

    Science.gov (United States)

    Moribayashi, Kengo

    2018-05-01

    Using simulations, we have evaluated the effect of the track potential on the motion and energy flow of secondary electrons, with the goal of determining the spatial distribution of energy deposition due to irradiation with heavy ions. We have simulated this effect as a function of the mean path τ between the incident ion-impact-ionization events at ion energies Eion. Here, the track potential is the potential formed from electric field near this incident ion path. The simulations indicate that this effect is mainly determined by τ and hardly depends on Eion. To understand heavy ion beam science more deeply and to reduce the time required by simulations, we have proposed simple approximation methods that almost reproduce the simulation results here.

  20. Orbital single particle tracking on a commercial confocal microscope using piezoelectric stage feedback

    International Nuclear Information System (INIS)

    Lanzanò, L; Gratton, E

    2014-01-01

    Single Particle Tracking (SPT) is a technique used to locate fluorescent particles with nanometer precision. In the orbital tracking method the position of a particle is obtained analyzing the distribution of intensity along a circular orbit scanned around the particle. In combination with an active feedback this method allows tracking of particles in 2D and 3D with millisecond temporal resolution. Here we describe a SPT setup based on a feedback approach implemented with minimal modification of a commercially available confocal laser scanning microscope, the Zeiss LSM 510, in combination with an external piezoelectric stage scanner. The commercial microscope offers the advantage of a user-friendly software interface and pre-calibrated hardware components. The use of an external piezo-scanner allows the addition of feedback into the system but also represents a limitation in terms of its mechanical response. We describe in detail this implementation of the orbital tracking method and discuss advantages and limitations. As an example of application to live cell experiments we perform the 3D tracking of acidic vesicles in live polarized epithelial cells. (paper)

  1. Real-time extraction of bubble chamber tracks using a single vidicon

    International Nuclear Information System (INIS)

    Roos, C.E.

    1978-01-01

    Bubble Chamber pictures show many undesired tracks and background in addition to the tracks of the desired significant event. Settles et al. have described a technique for optical tagging of an event by adding a darkfield photograph taken before significant bubble growth to a later brightfield photograph. The authors describe a system to cancel out all picture detail except for the wanted tracks by using a single vidicon tube as the storage device. In the first exposure, polarized light is imaged on the vidicon after passing through a Ronchi grating placed at a focal plane. Thus half of the target is exposed in a series of vertical stripes. The second exposure uses light polarized orthogonally to the first exposure and is deflected after passing through the Ronchi grating so as to expose the previously occluded stripes on the target. The target is then scanned orthogonally to the stripes; by subtracting the picture contained in one set of stripes from that contained in the other set, only the differences between the two images remains. A simulation was conducted using continuously presented background of one polarization and background plus tracks of the other polarization. The test showed that the added tracks were easily resolved, even though they were not readily discernible by visual inspection prior to subtraction. (Auth.)

  2. Unsupervised markerless 3-DOF motion tracking in real time using a single low-budget camera.

    Science.gov (United States)

    Quesada, Luis; León, Alejandro J

    2012-10-01

    Motion tracking is a critical task in many computer vision applications. Existing motion tracking techniques require either a great amount of knowledge on the target object or specific hardware. These requirements discourage the wide spread of commercial applications based on motion tracking. In this paper, we present a novel three degrees of freedom motion tracking system that needs no knowledge on the target object and that only requires a single low-budget camera that can be found installed in most computers and smartphones. Our system estimates, in real time, the three-dimensional position of a nonmodeled unmarked object that may be nonrigid, nonconvex, partially occluded, self-occluded, or motion blurred, given that it is opaque, evenly colored, enough contrasting with the background in each frame, and that it does not rotate. Our system is also able to determine the most relevant object to track in the screen. Our proposal does not impose additional constraints, therefore it allows a market-wide implementation of applications that require the estimation of the three position degrees of freedom of an object.

  3. Effects of model approximations for electron, hole, and photon transport in swift heavy ion tracks

    Energy Technology Data Exchange (ETDEWEB)

    Rymzhanov, R.A. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Medvedev, N.A., E-mail: nikita.medvedev@fzu.cz [Department of Radiation and Chemical Physics, Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Laser Plasma Department, Institute of Plasma Physics, Czech Academy of Sciences, Za Slovankou 3, 182 00 Prague 8 (Czech Republic); Volkov, A.E. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); National Research Centre ‘Kurchatov Institute’, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Lebedev Physical Institute of the Russian Academy of Sciences, Leninskij pr., 53,119991 Moscow (Russian Federation); National University of Science and Technology MISiS, Leninskij pr., 4, 119049 Moscow (Russian Federation); National Research Nuclear University MEPhI, Kashirskoye sh., 31, 115409 Moscow (Russian Federation)

    2016-12-01

    The event-by-event Monte Carlo code, TREKIS, was recently developed to describe excitation of the electron subsystems of solids in the nanometric vicinity of a trajectory of a nonrelativistic swift heavy ion (SHI) decelerated in the electronic stopping regime. The complex dielectric function (CDF) formalism was applied in the used cross sections to account for collective response of a matter to excitation. Using this model we investigate effects of the basic assumptions on the modeled kinetics of the electronic subsystem which ultimately determine parameters of an excited material in an SHI track. In particular, (a) effects of different momentum dependencies of the CDF on scattering of projectiles on the electron subsystem are investigated. The ‘effective one-band’ approximation for target electrons produces good coincidence of the calculated electron mean free paths with those obtained in experiments in metals. (b) Effects of collective response of a lattice appeared to dominate in randomization of electron motion. We study how sensitive these effects are to the target temperature. We also compare results of applications of different model forms of (quasi-) elastic cross sections in simulations of the ion track kinetics, e.g. those calculated taking into account optical phonons in the CDF form vs. Mott’s atomic cross sections. (c) It is demonstrated that the kinetics of valence holes significantly affects redistribution of the excess electronic energy in the vicinity of an SHI trajectory as well as its conversion into lattice excitation in dielectrics and semiconductors. (d) It is also shown that induced transport of photons originated from radiative decay of core holes brings the excess energy faster and farther away from the track core, however, the amount of this energy is relatively small.

  4. Modifications of gallium phosphide single crystals using slow highly charged ions and swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    El-Said, A.S., E-mail: elsaid@kfupm.edu.sa [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Wilhelm, R.A.; Heller, R.; Akhmadaliev, Sh.; Schumann, E. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Sorokin, M. [National Research Centre ’Kurchatov Institute’, Kurchatov Square 1, 123182 Moscow (Russian Federation); Facsko, S. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2016-09-01

    GaP single crystals were irradiated with slow highly charged ions (HCI) using 114 keV {sup 129}Xe{sup (33–40)+} and with various swift heavy ions (SHI) of 30 MeV I{sup 9+} and 374 MeV–2.2 GeV {sup 197}Au{sup 25+}. The irradiated surfaces were investigated by scanning force microscopy (SFM). The irradiations with SHI lead to nanohillocks protruding from the GaP surfaces, whereas no changes of the surface topography were observed after the irradiation with HCI. This result indicates that a potential energy above 38.5 keV is required for surface nanostructuring of GaP. In addition, strong coloration of the GaP crystals was observed after irradiation with SHI. The effect was stronger for higher energies. This was confirmed by measuring an increased extinction coefficient in the visible light region.

  5. Innovative molecular-based fluorescent nanoparticles for multicolor single particle tracking in cells

    International Nuclear Information System (INIS)

    Daniel, Jonathan; Blanchard-Desce, Mireille; Godin, Antoine G; Palayret, Matthieu; Lounis, Brahim; Cognet, Laurent

    2016-01-01

    Based on an original molecular-based design, we present bright and photostable fluorescent organic nanoparticles (FONs) showing excellent colloidal stability in various aqueous environments. Complementary near-infrared emitting and green emitting FONs were prepared using a simple, fast and robust protocol. Both types of FONs could be simultaneously imaged at the single-particle level in solution as well as in biological environments using a monochromatic excitation and a dual-color fluorescence microscope. No evidence of acute cytotoxicity was found upon incubation of live cells with mixed solutions of FONs, and both types of nanoparticles were found internalized in the cells where their motion could be simultaneously tracked at video-rate up to minutes. These fluorescent organic nanoparticles open a novel non-toxic alternative to existing nanoparticles for imaging biological structures, compatible with live-cell experiments and specially fitted for multicolor single particle tracking. (paper)

  6. Long-term tracking of multiple interacting pedestrians using a single camera

    CSIR Research Space (South Africa)

    Keaikitse, M

    2014-11-01

    Full Text Available interacting pedestrians using a single camera Mogomotsi Keaikitse∗, Willie Brink† and Natasha Govender∗ ∗Modelling and Digital Sciences, Council for Scientific and Industrial Research, Pretoria, South Africa †Department of Mathematical Sciences, Stellenbosch...-identified and their tracks extended. Standard, publicly available data sets are used to test the system. I. INTRODUCTION Closed circuit cameras are becoming widespread and preva- lent in cities and towns around the world, indicating that surveillance is an important issue...

  7. Monofunctional stealth nanoparticle for unbiased single molecule tracking inside living cells.

    Science.gov (United States)

    Lisse, Domenik; Richter, Christian P; Drees, Christoph; Birkholz, Oliver; You, Changjiang; Rampazzo, Enrico; Piehler, Jacob

    2014-01-01

    On the basis of a protein cage scaffold, we have systematically explored intracellular application of nanoparticles for single molecule studies and discovered that recognition by the autophagy machinery plays a key role for rapid metabolism in the cytosol. Intracellular stealth nanoparticles were achieved by heavy surface PEGylation. By combination with a generic approach for nanoparticle monofunctionalization, efficient labeling of intracellular proteins with high fidelity was accomplished, allowing unbiased long-term tracking of proteins in the outer mitochondrial membrane.

  8. Space and phase resolved ion energy and angular distributions in single- and dual-frequency capacitively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States); Moore, Nathaniel; Pribyl, Patrick; Gekelman, Walter [Department of Physics, University of California, Los Angeles, California 90095 (United States)

    2013-11-15

    The control of ion energy and angular distributions (IEADs) is critically important for anisotropic etching or deposition in microelectronic fabrication processes. With single frequency capacitively coupled plasmas (CCPs), the narrowing in angle and spread in energy of ions as they cross the sheath are definable functions of frequency, sheath width, and mean free path. With increases in wafer size, single frequency CCPs are finding difficulty in meeting the requirement of simultaneously controlling plasma densities, ion fluxes, and ion energies. Dual-frequency CCPs are being investigated to provide this flexible control. The high frequency (HF) is intended to control the plasma density and ion fluxes, while the ion energies are intended to be controlled by the low frequency (LF). However, recent research has shown that the LF can also influence the magnitude of ion fluxes and that IEADs are determined by both frequencies. Hence, separate control of fluxes and IEADs is complex. In this paper, results from a two-dimensional computational investigation of Ar/O{sub 2} plasma properties in an industrial reactor are discussed. The IEADs are tracked as a function of height above the substrate and phase within the rf cycles from the bulk plasma to the presheath and through the sheath with the goal of providing insights to this complexity. Comparison is made to laser-induced fluorescence experiments. The authors found that the ratios of HF/LF voltage and driving frequency are critical parameters in determining the shape of the IEADs, both during the transit of the ion through the sheath and when ions are incident onto the substrate. To the degree that contributions from the HF can modify plasma density, sheath potential, and sheath thickness, this may provide additional control for the IEADs.

  9. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Science.gov (United States)

    Fink, Dietmar; Vacik, Jiri; Hnatowicz, V.; Muñoz Hernandez, G.; Garcia Arrelano, H.; Alfonta, Lital; Kiv, Arik

    2017-05-01

    For understanding of the diffusion kinetics and their optimization in swift heavy ion track-based biosensors, recently a diffusion simulation was performed. This simulation aimed at yielding the degree of enrichment of the enzymatic reaction products in the highly confined space of the etched ion tracks. A bunch of curves was obtained for the description of such sensors that depend only on the ratio of the diffusion coefficient of the products to that of the analyte within the tracks. As hitherto none of these two diffusion coefficients is accurately known, the present work was undertaken. The results of this paper allow one to quantify the previous simulation and hence yield realistic predictions of glucose-based biosensors. At this occasion, also the influence of the etched track radius on the diffusion coefficients was measured and compared with earlier prediction.

  10. Single-Ion Implantation for the Development of Si-Based MOSFET Devices with Quantum Functionalities

    Directory of Open Access Journals (Sweden)

    Jeffrey C. McCallum

    2012-01-01

    Full Text Available Interest in single-ion implantation is driven in part by research into development of solid-state devices that exhibit quantum behaviour in their electronic or optical characteristics. Here, we provide an overview of international research work on single ion implantation and single ion detection for development of electronic devices for quantum computing. The scope of international research into single ion implantation is presented in the context of our own research in the Centre for Quantum Computation and Communication Technology in Australia. Various single ion detection schemes are presented, and limitations on dopant placement accuracy due to ion straggling are discussed together with pathways for scale-up to multiple quantum devices on the one chip. Possible future directions for ion implantation in quantum computing and communications are also discussed.

  11. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Hernandez, G. M.; Arrelano, H. G.; Alfonta, L.; Kiv, A.

    2017-01-01

    Roč. 398, MAY (2017), s. 21-26 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : etched ion tracks * track radius * polymer * enzyme * diffusion * biosensors Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Bioremediation, diagnostic biotechnologies (DNA chips and biosensing devices) in environmental management Impact factor: 1.109, year: 2016

  12. Measurement of the variable track-etch rate of hydrogen, carbon and oxygen Ions in CR-39

    International Nuclear Information System (INIS)

    Lengar, I.; Skvarc, J.; Ilic, R.

    2003-01-01

    The ratio of the track-etch rate to the bulk-etch rate for hydrogen, carbon and oxygen ions was studied for the CR-39 detector with addition of dioctylphthalate. The response was reconstructed from etch-pit growth curves obtained by the multi-step etching technique. A theoretical analysis of the correctness of the method due to the 'missing track segment' is assessed and utilisation of the results obtained for the calibration of fast neutron dosimetry is discussed. (author)

  13. Designing Artificial Solid-Electrolyte Interphases for Single-Ion and High-Efficiency Transport in Batteries

    KAUST Repository

    Tu, Zhengyuan; Choudhury, Snehashis; Zachman, Michael J.; Wei, Shuya; Zhang, Kaihang; Kourkoutis, Lena F.; Archer, Lynden A.

    2017-01-01

    energy storage technologies. In lithium-ion batteries, electrolytes with single- or near-single-ion conductivity reduce losses caused by ion polarization. In emergent lithium or sodium metal batteries, they maintain high conductivity at the anode

  14. Track structure based modelling of light ion radiation effects on nuclear and mitochondrial DNA

    Science.gov (United States)

    Schmitt, Elke; Ottolenghi, Andrea; Dingfelder, Michael; Friedland, Werner; Kundrat, Pavel; Baiocco, Giorgio

    2016-07-01

    Space radiation risk assessment is of great importance for manned spaceflights in order to estimate risks and to develop counter-measures to reduce them. Biophysical simulations with PARTRAC can help greatly to improve the understanding of initial biological response to ionizing radiation. Results from modelling radiation quality dependent DNA damage and repair mechanisms up to chromosomal aberrations (e.g. dicentrics) can be used to predict radiation effects depending on the kind of mixed radiation field exposure. Especially dicentric yields can serve as a biomarker for an increased risk due to radiation and hence as an indicator for the effectiveness of the used shielding. PARTRAC [1] is a multi-scale biophysical research MC code for track structure based initial DNA damage and damage response modelling. It integrates physics, radiochemistry, detailed nuclear DNA structure and molecular biology of DNA repair by NHEJ-pathway to assess radiation effects on cellular level [2]. Ongoing experiments with quasi-homogeneously distributed compared to sub-micrometre focused bunches of protons, lithium and carbon ions allow a separation of effects due to DNA damage complexity on nanometre scale from damage clustering on (sub-) micrometre scale [3, 4]. These data provide an unprecedented benchmark for the DNA damage response model in PARTRAC and help understand the mechanisms leading to cell killing and chromosomal aberrations (e.g. dicentrics) induction. A large part of space radiation is due to a mixed ion field of high energy protons and few heavier ions that can be only partly absorbed by the shielding. Radiation damage induced by low-energy ions significantly contributes to the high relative biological efficiency (RBE) of ion beams around Bragg peak regions. For slow light ions the physical cross section data basis in PARTRAC has been extended to investigate radiation quality effects in the Bragg peak region [5]. The resulting range and LET values agree with ICRU data

  15. Tracking Single Units in Chronic, Large Scale, Neural Recordings for Brain Machine Interface Applications

    Directory of Open Access Journals (Sweden)

    Ahmed eEleryan

    2014-07-01

    Full Text Available In the study of population coding in neurobiological systems, tracking unit identity may be critical to assess possible changes in the coding properties of neuronal constituents over prolonged periods of time. Ensuring unit stability is even more critical for reliable neural decoding of motor variables in intra-cortically controlled brain-machine interfaces (BMIs. Variability in intrinsic spike patterns, tuning characteristics, and single-unit identity over chronic use is a major challenge to maintaining this stability, requiring frequent daily calibration of neural decoders in BMI sessions by an experienced human operator. Here, we report on a unit-stability tracking algorithm that efficiently and autonomously identifies putative single-units that are stable across many sessions using a relatively short duration recording interval at the start of each session. The algorithm first builds a database of features extracted from units' average spike waveforms and firing patterns across many days of recording. It then uses these features to decide whether spike occurrences on the same channel on one day belong to the same unit recorded on another day or not. We assessed the overall performance of the algorithm for different choices of features and classifiers trained using human expert judgment, and quantified it as a function of accuracy and execution time. Overall, we found a trade-off between accuracy and execution time with increasing data volumes from chronically implanted rhesus macaques, with an average of 12 seconds processing time per channel at ~90% classification accuracy. Furthermore, 77% of the resulting putative single-units matched those tracked by human experts. These results demonstrate that over the span of a few months of recordings, automated unit tracking can be performed with high accuracy and used to streamline the calibration phase during BMI sessions.

  16. A reliable method for the counting and control of single ions for single-dopant controlled devices

    International Nuclear Information System (INIS)

    Shinada, T; Kurosawa, T; Nakayama, H; Zhu, Y; Hori, M; Ohdomari, I

    2008-01-01

    By 2016, transistor device size will be just 10 nm. However, a transistor that is doped at a typical concentration of 10 18 atoms cm -3 has only one dopant atom in the active channel region. Therefore, it can be predicted that conventional doping methods such as ion implantation and thermal diffusion will not be available ten years from now. We have been developing a single-ion implantation (SII) method that enables us to implant dopant ions one-by-one into semiconductors until the desired number is reached. Here we report a simple but reliable method to control the number of single-dopant atoms by detecting the change in drain current induced by single-ion implantation. The drain current decreases in a stepwise fashion as a result of the clusters of displaced Si atoms created by every single-ion incidence. This result indicates that the single-ion detection method we have developed is capable of detecting single-ion incidence with 100% efficiency. Our method potentially could pave the way to future single-atom devices, including a solid-state quantum computer

  17. Accurately tracking single-cell movement trajectories in microfluidic cell sorting devices.

    Science.gov (United States)

    Jeong, Jenny; Frohberg, Nicholas J; Zhou, Enlu; Sulchek, Todd; Qiu, Peng

    2018-01-01

    Microfluidics are routinely used to study cellular properties, including the efficient quantification of single-cell biomechanics and label-free cell sorting based on the biomechanical properties, such as elasticity, viscosity, stiffness, and adhesion. Both quantification and sorting applications require optimal design of the microfluidic devices and mathematical modeling of the interactions between cells, fluid, and the channel of the device. As a first step toward building such a mathematical model, we collected video recordings of cells moving through a ridged microfluidic channel designed to compress and redirect cells according to cell biomechanics. We developed an efficient algorithm that automatically and accurately tracked the cell trajectories in the recordings. We tested the algorithm on recordings of cells with different stiffness, and showed the correlation between cell stiffness and the tracked trajectories. Moreover, the tracking algorithm successfully picked up subtle differences of cell motion when passing through consecutive ridges. The algorithm for accurately tracking cell trajectories paves the way for future efforts of modeling the flow, forces, and dynamics of cell properties in microfluidics applications.

  18. Accurately tracking single-cell movement trajectories in microfluidic cell sorting devices.

    Directory of Open Access Journals (Sweden)

    Jenny Jeong

    Full Text Available Microfluidics are routinely used to study cellular properties, including the efficient quantification of single-cell biomechanics and label-free cell sorting based on the biomechanical properties, such as elasticity, viscosity, stiffness, and adhesion. Both quantification and sorting applications require optimal design of the microfluidic devices and mathematical modeling of the interactions between cells, fluid, and the channel of the device. As a first step toward building such a mathematical model, we collected video recordings of cells moving through a ridged microfluidic channel designed to compress and redirect cells according to cell biomechanics. We developed an efficient algorithm that automatically and accurately tracked the cell trajectories in the recordings. We tested the algorithm on recordings of cells with different stiffness, and showed the correlation between cell stiffness and the tracked trajectories. Moreover, the tracking algorithm successfully picked up subtle differences of cell motion when passing through consecutive ridges. The algorithm for accurately tracking cell trajectories paves the way for future efforts of modeling the flow, forces, and dynamics of cell properties in microfluidics applications.

  19. Grafting of acrylic acid on etched latent tracks induced by swift heavy ions on polypropylene films

    International Nuclear Information System (INIS)

    Mazzei, R.; Fernandez, A.; Garcia Bermudez, G.; Torres, A.; Gutierrez, M.C.; Magni, M.; Celma, G.; Tadey, D.

    2008-01-01

    In order to continue with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208 Pb of 25.62 MeV/n. Then, these were etched and grafted with acrylic acid (AA) monomers. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grating yield as a function of the fluence and etching time was obtained. In addition, the permeation of solutions, with different pH, through PP grafted foils was measured

  20. Strategy Selection of Film Irradiation by Accelerated ^{40}Ar^{8+} Ions for Manufacturing of Track Membranes

    CERN Document Server

    Denisov, Yu N; Kalinichenko, V V; Karamysheva, G A; Fedorenko, S B

    2004-01-01

    The industrial cyclotron CYTRACK is dedicated to the production of the track membranes. It is the basic instrument for the industry of membrane products to be consumed in medicine, biotechnology, pharmacology, microelectronics and many other industries. The cyclotron CYTRACK started working in the August of 2002. Argon ions were accelerated to a project energy of 2.4 MeV/nucleon, the extracted beam intensity was about 200 nA, the extraction efficiency totaled \\sim 50 %. In starting up operation the film was exposed in various controlled ways to charged particles with a view to achieving the values of parameters required for production of "Rosa" membranous plasmafilters. The pore uniformity in transverse direction was provided by beam scanning with a scanning magnet voltage of 73 V, the one in the longitudinal direction was provided by constancy of the film motion rate and stability of beam intensity during all the time of exposition.

  1. Single-ion and single-chain magnetism in triangular spin-chain oxides

    Science.gov (United States)

    Seikh, Md. Motin; Caignaert, Vincent; Perez, Olivier; Raveau, Bernard; Hardy, Vincent

    2017-05-01

    S r4 -xC axM n2Co O9 oxides (x =0 and x =2 ) are found to exhibit magnetic responses typical of single-chain magnets (SCMs) and single-ion magnets (SIMs), two features generally investigated in coordination polymers or complexes. The compound x =0 appears to be a genuine SCM, in that blocking effects associated with slow spin dynamics yield remanence and coercivity in the absence of long-range ordering (LRO). In addition, SIM signatures of nearly identical nature are detected in both compounds, coexisting with SCM in x =0 and with LRO in x =2 . It is also observed that a SCM response can be recovered in x =2 after application of magnetic field. These results suggest that purely inorganic systems could play a valuable role in the topical issue of the interplay among SIM, SCM, and LRO phenomena in low-dimensional magnetism.

  2. Performance study on the east-west oriented single-axis tracked panel

    International Nuclear Information System (INIS)

    Chang, Tian Pau

    2009-01-01

    A theoretical study on the performance of an east-west oriented single-axis tracked panel was originally proposed in this paper. Mathematic expressions applicable for calculating the angle that the tracked panel should rotate by to follow the Sun are derived. The incident angle of sunlight upon the panel as well as the instantaneous increments of solar energy captured by the panel relative to a fixed horizontal surface are then demonstrated graphically. To simulate different operation environments, three kinds of radiation sources will be considered, i.e. the extraterrestrial radiation, global radiation predicted by empirical models under clear sky situation and global radiation observed in Taiwan. Simulation results show that the yearly gains correlate positively with the radiation level, i.e. 21.2%, 13.5% and 7.4% for the extraterrestrial, predicted and observed radiations, respectively, which are far less than those obtained from a north-south oriented single-axis tracked panel. The irradiation increases with the maximum rotation angle of the panel, the benefit of increasing the rotation in overcast environment is not as good as in clear sky, for annual energy collection 45 o is recommended. The irradiation received decreases with latitude, but it has a greater gain in higher latitude zone.

  3. Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Musseau, O.; Torres, A.; Campbell, A.B.; Knudson, A.R.; Buchner, S.; Fischer, B.; Schloegl, M.; Briand, P.

    1999-12-01

    The authors present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. They used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a non-destructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a sudden change in the charge collection image. Hot spots are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.

  4. Anomalous effect of ion velocity on track formation in GeS

    Energy Technology Data Exchange (ETDEWEB)

    Szenes, G., E-mail: szenesgyorgy@caesar.elte.hu [Department of Materials Physics, Eötvös University, P.O. Box 32, H-1518 Budapest (Hungary); Pécz, B. [Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, 1525 Budapest, P.O. Box 49 (Hungary)

    2016-12-15

    Systematic experiments were performed for studying the effect of the projectile velocity (velocity effect, VE) in GeS which has a highly anisotropic conductivity. The prethinned specimens were irradiated by Bi, Au, W, Xe, Ag, Kr, Ni and Fe ions of about E ≈ 1 MeV/nucleon energy. Track radii were measured by transmission electron microscopy. Compared to previous experiments performed with high velocity projectile, there is a marked VE for S{sub e} > 20 keV/nm (S{sub e} – electronic stopping power). However, the VE is gradually reduced and finally disappears as S{sub e} decreases. This effect is described for the first time. The predictions according to the Analytical Thermal Spike Model are in excellent quantitative agreement with the experiments in the range S{sub e} > 20 keV/nm. The anomalous behavior of track evolution at lower values of S{sub e} is attributed to the combination of semiconducting and insulating properties. An explanation of the VE is given based on the Coulomb explosion model.

  5. Tracking single dynamic MEG dipole sources using the projected Extended Kalman Filter.

    Science.gov (United States)

    Yao, Yuchen; Swindlehurst, A Lee

    2011-01-01

    This paper presents two new algorithms based on the Extended Kalman Filter (EKF) for tracking the parameters of single dynamic magnetoencephalography (MEG) dipole sources. We assume a dynamic MEG dipole source with possibly both time-varying location and dipole orientation. The standard EKF-based tracking algorithm performs well under the assumption that the dipole source components vary in time as a Gauss-Markov process, provided that the background noise is temporally stationary. We propose a Projected-EKF algorithm that is adapted to a more forgiving condition where the background noise is temporally nonstationary, as well as a Projected-GLS-EKF algorithm that works even more universally, when the dipole components vary arbitrarily from one sample to the next.

  6. Measurements of energetic ions produced by high-energy laser pulses by means of solid-state nuclear track detectors

    Czech Academy of Sciences Publication Activity Database

    Szydlowski, A.; Badziak, A.; Parys, P.; Wolowski, J.; Woryna, E.; Jungwirth, Karel; Králiková, Božena; Krása, Josef; Láska, Leoš; Pfeifer, Miroslav; Rohlena, Karel; Skála, Jiří; Ullschmied, Jiří; Boody, F. D.; Gammino, S.; Torrisi, L.

    2004-01-01

    Roč. 7, č. 3 (2004), s. 327-332 ISSN 1093-3611 Institutional research plan: CEZ:AV0Z1010921 Keywords : iodine laser * nuclear track detectors * ions Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.194, year: 2004

  7. Novel single-cell mega-size chambers for electrochemical etching of panorama position-sensitive polycarbonate ion image detectors

    Science.gov (United States)

    Sohrabi, Mehdi

    2017-11-01

    A novel development is made here by inventing panorama single-cell mega-size electrochemical etching (MS-ECE) chamber systems for processing panorama position-sensitive mega-size polycarbonate ion image detectors (MS-PCIDs) of potential for many neutron and ion detection applications in particular hydrogen ions or proton tracks and images detected for the first time in polycarbonates in this study. The MS-PCID is simply a large polycarbonate sheet of a desired size. The single-cell MS-ECE invented consists of two large equally sized transparent Plexiglas sheets as chamber walls holding a MS-PCID and the ECE chamber components tightly together. One wall has a large flat stainless steel electrode (dry cell) attached to it which is directly in contact with the MS-PCID and the other wall has a rod electrode with two holes to facilitate feeding and draining out the etching solution from the wet cell. A silicon rubber washer plays the role of the wet cell to hold the etchant and the electrical insulator to isolate the dry cell from the wet cell. A simple 50 Hz-HV home-made generator provides an adequate field strength through the two electrodes across the MS-ECE chamber. Two panorama single-cell MS-ECE chamber systems (circular and rectangular shapes) constructed were efficiently applied to processing the MS-PCIDs for 4π ion emission image detection of different gases in particular hydrogen ions or protons in a 3.5 kJ plasma focus device (PFD as uniquely observed by the unaided eyes). The panorama MS-PCID/MS-ECE image detection systems invented are novel with high potential for many applications in particular as applied to 4π panorama ion emission angular distribution image detection studies in PFD space, some results of which are presented and discussed.

  8. Application of heavy-ion microbeam system at Kyoto University: Energy response for imaging plate by single ion irradiation

    International Nuclear Information System (INIS)

    Tosaki, M.; Nakamura, M.; Hirose, M.; Matsumoto, H.

    2011-01-01

    A heavy-ion microbeam system for cell irradiation has been developed using an accelerator at Kyoto University. We have successfully developed proton-, carbon-, fluorine- and silicon-beams in order to irradiate a micro-meter sized area with ion counting, especially single ion irradiation. In the heavy-ion microbeam system, an imaging plate (IP) was utilized for beam diagnostics on the irradiation. The IP is widely used for radiography studies in biology. However, there are a few studies on the low linear energy transfer (LET) by single ions, i.e., low-intensity exposure. Thus we have investigated the energy response for the IP, which can be utilized for microbeam diagnostics.

  9. Application of maximum entropy to statistical inference for inversion of data from a single track segment.

    Science.gov (United States)

    Stotts, Steven A; Koch, Robert A

    2017-08-01

    In this paper an approach is presented to estimate the constraint required to apply maximum entropy (ME) for statistical inference with underwater acoustic data from a single track segment. Previous algorithms for estimating the ME constraint require multiple source track segments to determine the constraint. The approach is relevant for addressing model mismatch effects, i.e., inaccuracies in parameter values determined from inversions because the propagation model does not account for all acoustic processes that contribute to the measured data. One effect of model mismatch is that the lowest cost inversion solution may be well outside a relatively well-known parameter value's uncertainty interval (prior), e.g., source speed from track reconstruction or towed source levels. The approach requires, for some particular parameter value, the ME constraint to produce an inferred uncertainty interval that encompasses the prior. Motivating this approach is the hypothesis that the proposed constraint determination procedure would produce a posterior probability density that accounts for the effect of model mismatch on inferred values of other inversion parameters for which the priors might be quite broad. Applications to both measured and simulated data are presented for model mismatch that produces minimum cost solutions either inside or outside some priors.

  10. Three-dimensional single-particle tracking in live cells: news from the third dimension

    International Nuclear Information System (INIS)

    Dupont, A; Wehnekamp, F; Katayama, Y; Lamb, D C; Gorelashvili, M; Schüller, V; Arcizet, D; Heinrich, D

    2013-01-01

    Single-particle tracking (SPT) is of growing importance in the biophysical community. It is used to investigate processes such as drug and gene delivery, viral uptake, intracellular trafficking or membrane-bound protein mobility. Traditionally, SPT is performed in two dimensions (2D) because of its technical simplicity. However, life occurs in three dimensions (3D) and many methods have been recently developed to track particles in 3D. Now, is the third dimension worth the effort? Here we investigate the differences between the 2D and 3D analyses of intracellular transport with the 3D development of a time-resolved mean square displacement (MSD) analysis introduced previously. The 3D trajectories, and the 2D projections, of fluorescent nanoparticles were obtained with an orbital tracking microscope in two different cell types: in Dictyostelium discoideum ameba and in adherent, more flattened HuH-7 human cells. As expected from the different 3D organization of both cells’ cytoskeletons, a third of the active transport was lost upon projection in the ameba whereas the identification of the active phases was barely affected in the HuH-7 cells. In both cell types, we found intracellular diffusion to be anisotropic and the diffusion coefficient values derived from the 2D analysis were therefore biased. (paper)

  11. Classification of team sport activities using a single wearable tracking device.

    Science.gov (United States)

    Wundersitz, Daniel W T; Josman, Casey; Gupta, Ritu; Netto, Kevin J; Gastin, Paul B; Robertson, Sam

    2015-11-26

    Wearable tracking devices incorporating accelerometers and gyroscopes are increasingly being used for activity analysis in sports. However, minimal research exists relating to their ability to classify common activities. The purpose of this study was to determine whether data obtained from a single wearable tracking device can be used to classify team sport-related activities. Seventy-six non-elite sporting participants were tested during a simulated team sport circuit (involving stationary, walking, jogging, running, changing direction, counter-movement jumping, jumping for distance and tackling activities) in a laboratory setting. A MinimaxX S4 wearable tracking device was worn below the neck, in-line and dorsal to the first to fifth thoracic vertebrae of the spine, with tri-axial accelerometer and gyroscope data collected at 100Hz. Multiple time domain, frequency domain and custom features were extracted from each sensor using 0.5, 1.0, and 1.5s movement capture durations. Features were further screened using a combination of ANOVA and Lasso methods. Relevant features were used to classify the eight activities performed using the Random Forest (RF), Support Vector Machine (SVM) and Logistic Model Tree (LMT) algorithms. The LMT (79-92% classification accuracy) outperformed RF (32-43%) and SVM algorithms (27-40%), obtaining strongest performance using the full model (accelerometer and gyroscope inputs). Processing time can be reduced through feature selection methods (range 1.5-30.2%), however a trade-off exists between classification accuracy and processing time. Movement capture duration also had little impact on classification accuracy or processing time. In sporting scenarios where wearable tracking devices are employed, it is both possible and feasible to accurately classify team sport-related activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Guidelines for the fitting of anomalous diffusion mean square displacement graphs from single particle tracking experiments.

    Directory of Open Access Journals (Sweden)

    Eldad Kepten

    Full Text Available Single particle tracking is an essential tool in the study of complex systems and biophysics and it is commonly analyzed by the time-averaged mean square displacement (MSD of the diffusive trajectories. However, past work has shown that MSDs are susceptible to significant errors and biases, preventing the comparison and assessment of experimental studies. Here, we attempt to extract practical guidelines for the estimation of anomalous time averaged MSDs through the simulation of multiple scenarios with fractional Brownian motion as a representative of a large class of fractional ergodic processes. We extract the precision and accuracy of the fitted MSD for various anomalous exponents and measurement errors with respect to measurement length and maximum time lags. Based on the calculated precision maps, we present guidelines to improve accuracy in single particle studies. Importantly, we find that in some experimental conditions, the time averaged MSD should not be used as an estimator.

  13. Metallic microwires obtained as replicas of etched ion tracks in polymer matrixes: Microscopy and emission properties

    International Nuclear Information System (INIS)

    Zagorski, D.L.; Bedin, S.A.; Oleinikov, V.A.; Polyakov, N.B.; Rybalko, O.G.; Mchedlishvili, B.V.

    2009-01-01

    Specially prepared porous matrixes (with through and dead-end pores of cylindrical or conical forms) were used as the templates for making ensembles of microwires. The process of electrodeposition of metal (Cu) into these pores was investigated. AFM technique was used for studying the 'composite material' (metal microwires embedded into the polymer matrix). It was shown that the combination of different modes of AFM (tapping with phase-contrast mode, contact with lateral force mode) makes it possible to detect metal in the polymer matrix. Additional spread resistance mode in the contact regime allowed to measure the electrical conductivity of a single wire. The ensembles of free-standing microwires (metallic replicas of the pores obtained after removing of the polymer matrix) were used as the substrates (for deposition of the probe) for ion emission in the mass-spectrometer. It was shown that the intensity of formed ion beam increases with increasing of power of the laser pulse and with increasing of the mass of the probe. The intensity of mass-spectra signal on the power of laser pulse has a threshold character with saturation accompanied with the appearance of dimer ions. At the same time this intensity decreases with the increasing of the surface density of wires. The effect of degradation of wires during the laser pulse irradiation was found.

  14. A multi-parametric particle-pairing algorithm for particle tracking in single and multiphase flows

    International Nuclear Information System (INIS)

    Cardwell, Nicholas D; Vlachos, Pavlos P; Thole, Karen A

    2011-01-01

    Multiphase flows (MPFs) offer a rich area of fundamental study with many practical applications. Examples of such flows range from the ingestion of foreign particulates in gas turbines to transport of particles within the human body. Experimental investigation of MPFs, however, is challenging, and requires techniques that simultaneously resolve both the carrier and discrete phases present in the flowfield. This paper presents a new multi-parametric particle-pairing algorithm for particle tracking velocimetry (MP3-PTV) in MPFs. MP3-PTV improves upon previous particle tracking algorithms by employing a novel variable pair-matching algorithm which utilizes displacement preconditioning in combination with estimated particle size and intensity to more effectively and accurately match particle pairs between successive images. To improve the method's efficiency, a new particle identification and segmentation routine was also developed. Validation of the new method was initially performed on two artificial data sets: a traditional single-phase flow published by the Visualization Society of Japan (VSJ) and an in-house generated MPF data set having a bi-modal distribution of particles diameters. Metrics of the measurement yield, reliability and overall tracking efficiency were used for method comparison. On the VSJ data set, the newly presented segmentation routine delivered a twofold improvement in identifying particles when compared to other published methods. For the simulated MPF data set, measurement efficiency of the carrier phases improved from 9% to 41% for MP3-PTV as compared to a traditional hybrid PTV. When employed on experimental data of a gas–solid flow, the MP3-PTV effectively identified the two particle populations and reported a vector efficiency and velocity measurement error comparable to measurements for the single-phase flow images. Simultaneous measurement of the dispersed particle and the carrier flowfield velocities allowed for the calculation of

  15. Single particle tracking reveals spatial and dynamic organization of the Escherichia coli biofilm matrix

    International Nuclear Information System (INIS)

    Birjiniuk, Alona; Doyle, Patrick S; Billings, Nicole; Ribbeck, Katharina; Nance, Elizabeth; Hanes, Justin

    2014-01-01

    Biofilms are communities of surface-adherent bacteria surrounded by secreted polymers known as the extracellular polymeric substance. Biofilms are harmful in many industries, and thus it is of great interest to understand their mechanical properties and structure to determine ways to destabilize them. By performing single particle tracking with beads of varying surface functionalization it was found that charge interactions play a key role in mediating mobility within biofilms. With a combination of single particle tracking and microrheological concepts, it was found that Escherichia coli biofilms display height dependent charge density that evolves over time. Statistical analyses of bead trajectories and confocal microscopy showed inter-connecting micron scale channels that penetrate throughout the biofilm, which may be important for nutrient transfer through the system. This methodology provides significant insight into a particular biofilm system and can be applied to many others to provide comparisons of biofilm structure. The elucidation of structure provides evidence for the permeability of biofilms to microscale objects, and the ability of a biofilm to mature and change properties over time. (paper)

  16. Robust model-based analysis of single-particle tracking experiments with Spot-On

    Science.gov (United States)

    Grimm, Jonathan B; Lavis, Luke D

    2018-01-01

    Single-particle tracking (SPT) has become an important method to bridge biochemistry and cell biology since it allows direct observation of protein binding and diffusion dynamics in live cells. However, accurately inferring information from SPT studies is challenging due to biases in both data analysis and experimental design. To address analysis bias, we introduce ‘Spot-On’, an intuitive web-interface. Spot-On implements a kinetic modeling framework that accounts for known biases, including molecules moving out-of-focus, and robustly infers diffusion constants and subpopulations from pooled single-molecule trajectories. To minimize inherent experimental biases, we implement and validate stroboscopic photo-activation SPT (spaSPT), which minimizes motion-blur bias and tracking errors. We validate Spot-On using experimentally realistic simulations and show that Spot-On outperforms other methods. We then apply Spot-On to spaSPT data from live mammalian cells spanning a wide range of nuclear dynamics and demonstrate that Spot-On consistently and robustly infers subpopulation fractions and diffusion constants. PMID:29300163

  17. Output energy of a photovoltaic module mounted on a single-axis tracking system

    International Nuclear Information System (INIS)

    Chang, Tian Pau

    2009-01-01

    In this study, the electric energy from a photovoltaic module was calculated theoretically at different azimuths and tilt angles in Taiwan. The gain of the module mounted on a single-axis tracking panel relative to a traditional fixed panel was analyzed. To simulate different operation environments, both types of radiation will be considered in addition to observed radiation, i.e. the extraterrestrial radiation and the global radiation predicted by an empirical model. The results show that the optimal tilt angle obtained from the observed data is flatter than those from other two radiation types and becomes flatter while the panel deviates from due south. The yearly gains obtained from the extraterrestrial, predicted and observed radiations are 51.4%, 28.5% and 18.7%, respectively, if a single-axis tracked panel is installed with the yearly optimal tilt angle; the similar gains are 45.3%, 25.9% and 17.5%, respectively, while the panel is adjusted to its monthly optimal angle each month. The amount of yearly energy in due west (or east) is less than its maximum in due south by about 11%, 10% and 5% for the extraterrestrial, predicted and observed radiation respectively. The yearly conversion efficiency of a fixed module is 10.2%, 9.2% and 8.3% for the extraterrestrial, predicted and observed radiation, respectively.

  18. 3D dual-virtual-pinhole assisted single particle tracking microscopy

    International Nuclear Information System (INIS)

    Ma, Ye; Wang, Yifan; Zhou, Xin; Kuang, Cuifang; Liu, Xu

    2014-01-01

    We propose a novel approach for high-speed, three-dimensional single particle tracking (SPT), which we refer to as dual-virtual-pinhole assisted single particle tracking microscopy (DVPaSPTM). DVPaSPTM system can obtain axial information of the sample without optical or mechanical depth scanning, so as to offer numbers of advantages including faster imaging, improved efficiency and a great reduction of photobleaching and phototoxicity. In addition, by the use of the dual-virtual-pinhole, the effect that the quantum yield exerts to the fluorescent signal can be eliminated, which makes the measurement independent of the surroundings and increases the accuracy of the result. DVPaSPTM system measures the intensity within different virtual pinholes of which the radii are given by the host computer. Axial information of fluorophores can be measured by the axial response curve through the ratio of intensity signals. We demonstrated the feasibility of the proposed method by a series of experiments. Results showed that the standard deviation of the axial measurement was 19.2 nm over a 2.5 μm range with 30 ms temporal resolution. (papers)

  19. Dual-modality single particle orientation and rotational tracking of intracellular transport of nanocargos.

    Science.gov (United States)

    Sun, Wei; Gu, Yan; Wang, Gufeng; Fang, Ning

    2012-01-17

    The single particle orientation and rotational tracking (SPORT) technique was introduced recently to follow the rotational motion of plasmonic gold nanorod under a differential interference contrast (DIC) microscope. In biological studies, however, cellular activities usually involve a multiplicity of molecules; thus, tracking the motion of a single molecule/object is insufficient. Fluorescence-based techniques have long been used to follow the spatial and temporal distributions of biomolecules of interest thanks to the availability of multiplexing fluorescent probes. To know the type and number of molecules and the timing of their involvement in a biological process under investigation by SPORT, we constructed a dual-modality DIC/fluorescence microscope to simultaneously image fluorescently tagged biomolecules and plasmonic nanoprobes in living cells. With the dual-modality SPORT technique, the microtubule-based intracellular transport can be unambiguously identified while the dynamic orientation of nanometer-sized cargos can be monitored at video rate. Furthermore, the active transport on the microtubule can be easily separated from the diffusion before the nanocargo docks on the microtubule or after it undocks from the microtubule. The potential of dual-modality SPORT is demonstrated for shedding new light on unresolved questions in intracellular transport.

  20. Nested Penning Trap as a Source of Singly Charged Ions

    International Nuclear Information System (INIS)

    Ordonez, C.A.

    2003-01-01

    In the work reported, the possibility of using a nested Penning trap as a high purity source of low-charge-state ions is studied. For the configuration considered, a relatively dense ion plasma is confined by a three-dimensional electric potential well. The three-dimensional well is produced by the electric field generated by both the trap electrodes and a trapped electron plasma. The ion and electron plasmas are each considered to have Maxwellian velocity distributions. However, it is shown that the electron plasma must have a temperature that is higher than that of the ion plasma when the ions have low charge states. The work reported includes a self-consistent prediction of a possible plasma equilibrium

  1. Creation and recovery of a W(111) single atom gas field ion source

    International Nuclear Information System (INIS)

    Pitters, Jason L.; Urban, Radovan; Wolkow, Robert A.

    2012-01-01

    Tungsten single atom tips have been prepared from a single crystal W(111) oriented wire using the chemical assisted field evaporation and etching method. Etching to a single atom tip occurs through a symmetric structure and leads to a predictable last atom unlike etching with polycrystalline tips. The single atom tip formation procedure is shown in an atom by atom removal process. Rebuilds of single atom tips occur on the same crystalline axis as the original tip such that ion emission emanates along a fixed direction for all tip rebuilds. This preparation method could be utilized and developed to prepare single atom tips for ion source development.

  2. Development and tests of an anode readout TPC with high track separability for large solid angle relativistic ion experiments

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.; Foley, K.J.; Eiseman, S.E.

    1988-01-01

    We have developed, constructed and tested an anode readout TPC with high track separability which is suitable for large solid angle relativistic ion experiments. The readout via rows of short anode wires parallel to the beam has been found in tests to allow two-track separability of ∼2-3 mm. The efficiency of track reconstruction for events from a target, detected inside the MPS 5 KG magnet, is estimated to be >90% for events made by incident protons and pions. 15 GeV/c x A Si ion beams at a rate of ∼25 K per AGS pulse were permitted to course through the chamber and did not lead to any problems. When the gain was reduced to simulate the total output of a minimum ionizing particle, many Si ion tracks were also detected simultaneously with high efficiency. The resolution along the drift direction (parallel to the MPS magnetic field and perpendicular to the beam direction) was <1 mm and the resolution along the other direction /perpendicular/ to the beam direction was <1 mm also. 3 refs., 5 figs

  3. Thin film growth into the ion track structures in polyimide by atomic layer deposition

    Science.gov (United States)

    Mättö, L.; Malm, J.; Arstila, K.; Sajavaara, T.

    2017-09-01

    High-aspect ratio porous structures with controllable pore diameters and without a stiff substrate can be fabricated using the ion track technique. Atomic layer deposition is an ideal technique for depositing thin films and functional surfaces on complicated 3D structures due to the high conformality of the films. In this work, we studied Al2O3 and TiO2 films grown by ALD on pristine polyimide (Kapton HN) membranes as well as polyimide membranes etched in sodium hypochlorite (NaOCl) and boric acid (BO3) solution by means of RBS, PIXE, SEM-EDX and helium ion microcopy (HIM). The focus was on the first ALD growth cycles. The areal density of Al2O3 film in the 400 cycle sample was determined to be 51 ± 3 × 1016 at./cm2, corresponding to the thickness of 55 ± 3 nm. Furthermore, the growth per cycle was 1.4 Å/cycle. The growth is highly linear from the first cycles. In the case of TiO2, the growth per cycle is clearly slower during the first 200 cycles but then it increases significantly. The growth rate based on RBS measurements is 0.24 Å/cycle from 3 to 200 cycles and then 0.6 Å/cycle between 200 and 400 cycles. The final areal density of TiO2 film after 400 cycles is 148 ± 3 × 1015 at./cm2 which corresponds to the thickness of 17.4 ± 0.4 nm. The modification of the polyimide surface by etching prior to the deposition did not have an effect on the Al2O3 and TiO2 growth.

  4. Principles and biophysical applications of single particle super-localization and rotational tracking

    Science.gov (United States)

    Gu, Yan

    While conventional Single Particle Tracking (SPT) techniques acquire 2D or 3D trajectories of particle probes, we have developed Single Particle Orientation and Rotational Tracking (SPORT) techniques to extract orientation and rotational information. Combined with DIC microscopy, the SPORT technique has been applied in biophysical studies, including membrane diffusion and intracellular transport. The rotational dynamics of nanoparticle vectors on live cell membranes was recorded and its influence on the fate of these nanoparticle vectors was elucidated. The rotational motions of gold nanorods with various surface modifiers were tracked continuously at a temporal resolution of 5 ms under a DIC microscope. We found that the rotational behaviors of gold nanorod vectors are strongly related to their surface charge, specific surface functional groups, and the availability of receptors on cell membranes. The study of rotational Brownian motion of nanoparticles on cell membranes will lead to a better understanding of the mechanisms of drug delivery and provide guidance in designing surface modification strategies for drug delivery vectors under various circumstances. To characterize the rotation mode of surface functionalized gold nanorods on cell membranes, the SPORT technique is combined with the correlation analysis of the bright and dark DIC intensities. The unique capabilities of visualizing and understanding rotational motions of functionalized nanoparticles on live cell membranes allow us to correlate rotational and translational dynamics in unprecedented detail and provide new insights for complex membrane processes, including electrostatic interactions, ligand-receptor binding, and lateral (confined and hopping) diffusion of membrane receptors. Surface-functionalized nanoparticles interact with the membrane in fundamentally different ways and exhibit distinct rotational modes. The early events of particle-membrane approach and attachment are directly visualized

  5. Principles and biophysical applications of single particle super-localization and rotational tracking

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yan [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    While conventional Single Particle Tracking (SPT) techniques acquire 2D or 3D trajectories of particle probes, we have developed Single Particle Orientation and Rotational Tracking (SPORT) techniques to extract orientation and rotational information. Combined with DIC microscopy, the SPORT technique has been applied in biophysical studies, including membrane diffusion and intracellular transport. The rotational dynamics of nanoparticle vectors on live cell membranes was recorded and its influence on the fate of these nanoparticle vectors was elucidated. The rotational motions of gold nanorods with various surface modifiers were tracked continuously at a temporal resolution of 5 ms under a DIC microscope. We found that the rotational behaviors of gold nanorod vectors are strongly related to their surface charge, specific surface functional groups, and the availability of receptors on cell membranes. The study of rotational Brownian motion of nanoparticles on cell membranes will lead to a better understanding of the mechanisms of drug delivery and provide guidance in designing surface modification strategies for drug delivery vectors under various circumstances. To characterize the rotation mode of surface functionalized gold nanorods on cell membranes, the SPORT technique is combined with the correlation analysis of the bright and dark DIC intensities. The unique capabilities of visualizing and understanding rotational motions of functionalized nanoparticles on live cell membranes allow us to correlate rotational and translational dynamics in unprecedented detail and provide new insights for complex membrane processes, including electrostatic interactions, ligand-receptor binding, and lateral (confined and hopping) diffusion of membrane receptors. Surface-functionalized nanoparticles interact with the membrane in fundamentally different ways and exhibit distinct rotational modes. The early events of particle-membrane approach and attachment are directly visualized

  6. Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

    Science.gov (United States)

    McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; NEXT Collaboration

    2018-03-01

    A new method to tag the barium daughter in the double-beta decay of Xe 136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++ ) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (˜2 nm ), and detected with a statistical significance of 12.9 σ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

  7. Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

    2018-03-01

    A new method to tag the barium daughter in the double beta decay of $^{136}$Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba$^{++}$) resolution at a transparent scanning surface has been demonstrated. A single-step photo-bleach confirms the single ion interpretation. Individual ions are localized with super-resolution ($\\sim$2~nm), and detected with a statistical significance of 12.9~$\\sigma$ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

  8. Single-cell tracking reveals antibiotic-induced changes in mycobacterial energy metabolism.

    Science.gov (United States)

    Maglica, Željka; Özdemir, Emre; McKinney, John D

    2015-02-17

    ATP is a key molecule of cell physiology, but despite its importance, there are currently no methods for monitoring single-cell ATP fluctuations in live bacteria. This is a major obstacle in studies of bacterial energy metabolism, because there is a growing awareness that bacteria respond to stressors such as antibiotics in a highly individualistic manner. Here, we present a method for long-term single-cell tracking of ATP levels in Mycobacterium smegmatis based on a combination of microfluidics, time-lapse microscopy, and Förster resonance energy transfer (FRET)-based ATP biosensors. Upon treating cells with antibiotics, we observed that individual cells undergo an abrupt and irreversible switch from high to low intracellular ATP levels. The kinetics and extent of ATP switching clearly discriminate between an inhibitor of ATP synthesis and other classes of antibiotics. Cells that resume growth after 24 h of antibiotic treatment maintain high ATP levels throughout the exposure period. In contrast, antibiotic-treated cells that switch from ATP-high to ATP-low states never resume growth after antibiotic washout. Surprisingly, only a subset of these nongrowing ATP-low cells stains with propidium iodide (PI), a widely used live/dead cell marker. These experiments also reveal a cryptic subset of cells that do not resume growth after antibiotic washout despite remaining ATP high and PI negative. We conclude that ATP tracking is a more dynamic, sensitive, reliable, and discriminating marker of cell viability than staining with PI. This method could be used in studies to evaluate antimicrobial effectiveness and mechanism of action, as well as for high-throughput screening. New antimicrobials are urgently needed to stem the rising tide of antibiotic-resistant bacteria. All antibiotics are expected to affect bacterial energy metabolism, directly or indirectly, yet tools to assess the impact of antibiotics on the ATP content of individual bacterial cells are lacking. The

  9. Comparison of single-ion molecular dynamics in common solvents

    Science.gov (United States)

    Muralidharan, A.; Pratt, L. R.; Chaudhari, M. I.; Rempe, S. B.

    2018-06-01

    Laying a basis for molecularly specific theory for the mobilities of ions in solutions of practical interest, we report a broad survey of velocity autocorrelation functions (VACFs) of Li+ and PF6- ions in water, ethylene carbonate, propylene carbonate, and acetonitrile solutions. We extract the memory function, γ(t), which characterizes the random forces governing the mobilities of ions. We provide comparisons controlling for the effects of electrolyte concentration and ion-pairing, van der Waals attractive interactions, and solvent molecular characteristics. For the heavier ion (PF6-), velocity relaxations are all similar: negative tail relaxations for the VACF and a clear second relaxation for γ (t ), observed previously also for other molecular ions and with n-pentanol as the solvent. For the light Li+ ion, short time-scale oscillatory behavior masks simple, longer time-scale relaxation of γ (t ). But the corresponding analysis of the solventberg Li+(H2O)4 does conform to the standard picture set by all the PF6- results.

  10. Novel, Solvent-Free, Single Ion Conductive Polymer Electrolytes

    National Research Council Canada - National Science Library

    Florjanczyk, Zbigniew

    2008-01-01

    This project report concerns studies on the synthesis of new polymer electrolytes for application in lithium and lithium-ion batteries characterized by limited participation of anions in the transport...

  11. Tracking the ultrafast motion of a single molecule by femtosecond orbital imaging

    Science.gov (United States)

    Cocker, Tyler L.; Peller, Dominik; Yu, Ping; Repp, Jascha; Huber, Rupert

    2016-11-01

    Watching a single molecule move on its intrinsic timescale has been one of the central goals of modern nanoscience, and calls for measurements that combine ultrafast temporal resolution with atomic spatial resolution. Steady-state experiments access the requisite spatial scales, as illustrated by direct imaging of individual molecular orbitals using scanning tunnelling microscopy or the acquisition of tip-enhanced Raman and luminescence spectra with sub-molecular resolution. But tracking the intrinsic dynamics of a single molecule directly in the time domain faces the challenge that interactions with the molecule must be confined to a femtosecond time window. For individual nanoparticles, such ultrafast temporal confinement has been demonstrated by combining scanning tunnelling microscopy with so-called lightwave electronics, which uses the oscillating carrier wave of tailored light pulses to directly manipulate electronic motion on timescales faster even than a single cycle of light. Here we build on ultrafast terahertz scanning tunnelling microscopy to access a state-selective tunnelling regime, where the peak of a terahertz electric-field waveform transiently opens an otherwise forbidden tunnelling channel through a single molecular state. It thereby removes a single electron from an individual pentacene molecule’s highest occupied molecular orbital within a time window shorter than one oscillation cycle of the terahertz wave. We exploit this effect to record approximately 100-femtosecond snapshot images of the orbital structure with sub-ångström spatial resolution, and to reveal, through pump/probe measurements, coherent molecular vibrations at terahertz frequencies directly in the time domain. We anticipate that the combination of lightwave electronics and the atomic resolution of our approach will open the door to visualizing ultrafast photochemistry and the operation of molecular electronics on the single-orbital scale.

  12. High temperature electron beam ion source for the production of single charge ions of most elements of the Periodic Table

    CERN Document Server

    Panteleev, V N; Barzakh, A E; Fedorov, D V; Ivanov, V S; Moroz, F V; Orlov, S Y; Seliverstov, D M; Stroe, L; Tecchio, L B; Volkov, Y M

    2003-01-01

    A new type of a high temperature electron beam ion source (HTEBIS) with a working temperature up to 2500 deg. C was developed for production of single charge ions of practically all elements. Off-line tests and on-line experiments making use of the developed ion source coupled with uranium carbide targets of different density, have been carried out. The ionization efficiency measured for stable atoms of many elements varied in the interval of 1-6%. Using the HTEBIS, the yields and on-line production efficiency of neutron rich isotopes of Mn, Fe, Co, Cu, Rh, Pd, Ag, Cd, In, Sn and isotopes of heavy elements Pb, Bi, Po and some others have been determined. The revealed confinement effect of the ions produced in the narrow electron beam inside a hot ion source cavity has been discussed.

  13. TrackArt: the user friendly interface for single molecule tracking data analysis and simulation applied to complex diffusion in mica supported lipid bilayers.

    Science.gov (United States)

    Matysik, Artur; Kraut, Rachel S

    2014-05-01

    Single molecule tracking (SMT) analysis of fluorescently tagged lipid and protein probes is an attractive alternative to ensemble averaged methods such as fluorescence correlation spectroscopy (FCS) or fluorescence recovery after photobleaching (FRAP) for measuring diffusion in artificial and plasma membranes. The meaningful estimation of diffusion coefficients and their errors is however not straightforward, and is heavily dependent on sample type, acquisition method, and equipment used. Many approaches require advanced computing and programming skills for their implementation. Here we present TrackArt software, an accessible graphic interface for simulation and complex analysis of multiple particle paths. Imported trajectories can be filtered to eliminate spurious or corrupted tracks, and are then analyzed using several previously described methodologies, to yield single or multiple diffusion coefficients, their population fractions, and estimated errors. We use TrackArt to analyze the single-molecule diffusion behavior of a sphingolipid analog SM-Atto647N, in mica supported DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) bilayers. Fitting with a two-component diffusion model confirms the existence of two separate populations of diffusing particles in these bilayers on mica. As a demonstration of the TrackArt workflow, we characterize and discuss the effective activation energies required to increase the diffusion rates of these populations, obtained from Arrhenius plots of temperature-dependent diffusion. Finally, TrackArt provides a simulation module, allowing the user to generate models with multiple particle trajectories, diffusing with different characteristics. Maps of domains, acting as impermeable or permeable obstacles for particles diffusing with given rate constants and diffusion coefficients, can be simulated or imported from an image. Importantly, this allows one to use simulated data with a known diffusion behavior as a comparison for results

  14. Design Of Single-Axis And Dual-Axis Solar Tracking Systems Protected Against High Wind Speeds

    Directory of Open Access Journals (Sweden)

    Mai Salaheldin Elsherbiny

    2017-09-01

    Full Text Available Solar energy is rapidly gaining ground as an important mean of expanding renewable energy use. Solar tracking is employed in order to maximize collected solar radiation by a photovoltaic panel. In this paper we present a prototype for Automatic solar tracker that is designed using Arduino UNO with Wind sensor to Cease Wind effect on panels if wind speed exceeds certain threshold. The Proposed solar tracker tracks the location of the sun anywhere in any time by calculating the position of the sun. For producing the maximum amount of solar energy a solar panel must always be perpendicular to the source of light. Because the sun motion plane varies daily and during the day it moves from east to west one needs two axis tracking to follow the suns position. Maximum possible power is collected when two axis tracking is done. However two axis tracking is relatively costly and complex. A compromise between maximum power collection and system simplicity is obtained by single axis tracking where the plane North south axis is fixed while the east west motion is accomplished. This work deals with the design of both single and two axis tracking systems. Automatic trackers is also compared to Fixed one in terms of Energy generated Efficiency Cost and System reliability.

  15. Design and Development of a Solar Thermal Collector with Single Axis Solar Tracking Mechanism

    Directory of Open Access Journals (Sweden)

    Theebhan Mogana

    2016-01-01

    Full Text Available The solar energy is a source of energy that is abundant in Malaysia and can be easily harvested. However, because of the rotation of the Earth about its axis, it is impossible to harvest the solar energy to the maximum capacity if the solar thermal collector is placed fix to a certain angle. In this research, a solar thermal dish with single axis solar tracking mechanism that will rotate the dish according to the position of the sun in the sky is designed and developed, so that more solar rays can be reflected to a focal point and solar thermal energy can be harvested from the focal point. Data were collected for different weather conditions and performance of the solar thermal collector with a solar tracker were studied and compared with stationary solar thermal collector.

  16. A Simple Setup to Perform 3D Locomotion Tracking in Zebrafish by Using a Single Camera

    Directory of Open Access Journals (Sweden)

    Gilbert Audira

    2018-02-01

    Full Text Available Generally, the measurement of three-dimensional (3D swimming behavior in zebrafish relies on commercial software or requires sophisticated scripts, and depends on more than two cameras to capture the video. Here, we establish a simple and economic apparatus to detect 3D locomotion in zebrafish, which involves a single camera capture system that records zebrafish movement in a specially designed water tank with a mirror tilted at 45 degrees. The recorded videos are analyzed using idTracker, while spatial positions are calibrated by ImageJ software and 3D trajectories are plotted by Origin 9.1 software. This easy setting allowed scientists to track 3D swimming behavior of multiple zebrafish with low cost and precise spatial position, showing great potential for fish behavioral research in the future.

  17. Probing the type of anomalous diffusion with single-particle tracking.

    Science.gov (United States)

    Ernst, Dominique; Köhler, Jürgen; Weiss, Matthias

    2014-05-07

    Many reactions in complex fluids, e.g. signaling cascades in the cytoplasm of living cells, are governed by a diffusion-driven encounter of reactants. Yet, diffusion in complex fluids often exhibits an anomalous characteristic ('subdiffusion'). Since different types of subdiffusion have distinct effects on timing and equilibria of chemical reactions, a thorough determination of the reactants' type of random walk is key to a quantitative understanding of reactions in complex fluids. Here we introduce a straightforward and simple approach for determining the type of subdiffusion from single-particle tracking data. Unlike previous approaches, our method also is sensitive to transient subdiffusion phenomena, e.g. obstructed diffusion below the percolation threshold. We validate our strategy with data from experiment and simulation.

  18. Effect of ion velocity on creation of point defects halos of latent tracks in LiF

    Czech Academy of Sciences Publication Activity Database

    Volkov, A.E.; Schwartz, K.; Medvedev, Nikita; Trautmann, C.

    2017-01-01

    Roč. 407, Sep (2017), s. 80-85 ISSN 0168-583X R&D Projects: GA MŠk LG15013; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 Keywords : swift heavy ion * electronic stopping * track * LiF * color centers * defect halo Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.109, year: 2016

  19. Coupled chemical reactions in dynamic nanometric confinement: VII. Biosensors based on swift heavy ion tracks with membranes

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Alfonta, L.; Vacík, Jiří; Kiv, A.; Hnatowicz, Vladimír

    2017-01-01

    Roč. 172, 1-2 (2017), s. 159-173 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : biotechnology * tracks * swift heavy ions * polymers * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nano-materials (production and properties) Impact factor: 0.443, year: 2016

  20. Development of a keV single-ion-implanter for nanofabrication

    International Nuclear Information System (INIS)

    Yang, C.; Jamieson, D.N.; Hopf, T.; Tamanyan, G.; Spizziri, P.; Pakes, C.; Andresen, S.E.; Hudson, F.; Gauja, E.; Dzurak, A.; Clark, R.G.

    2005-01-01

    Traditional methods of doping semiconductors have a difficulty meeting the demand for high precision doping due to large statistical fluctuations in the numbers of dopant atoms introduced in the ever shrinking volume in micro- and nano-electronics devices, especially when the fabrication process approaches the nanometre scale. The statistical fluctuations in doping semiconductors for the fabrication of devices with a very small feature size may lead to inconsistent and unreliable performance. This paper describes the adaptation of a commercial ion implanter into a single-ion-implantation system for the accurate delivery of dopants into a nanometre or micrometre area in a silicon substrate. All the implanted ions can be accurately counted with near 100% certainty through online detection using the silicon substrate itself as an ion detector. A variety of ion species including B + , N + , P + at the energy range of 10-15 keV can be delivered in the single ion implantation system. (author). 6 refs., 6 figs

  1. Development of heavy-ion irradiation technique for single-event in semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Norio; Akutsu, Takao; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Naitoh, Ichiro; Itoh, Hisayoshi; Agematsu, Takashi; Kamiya, Tomihiro; Nashiyama, Isamu

    1997-03-01

    Heavy-ion irradiation technique has been developed for the evaluation of single-event effects on semiconductor devices. For the uniform irradiation of high energy heavy ions to device samples, we have designed and installed a magnetic beam-scanning system in a JAERI cyclotron beam course. It was found that scanned area was approximately 4 x 2 centimeters and that the deviation of ion fluence from the average value was less than 7%. (author)

  2. Characterization of microdose damage caused by single heavy ion observed in trench type power MOSFETs

    International Nuclear Information System (INIS)

    Ikeda, Naomi; Kuboyama, Satoshi; Maru, Akifumi; Tamura, Takashi; Hirao, Toshio; Abe, Hiroshi

    2010-01-01

    It was demonstrated that anomalously large degradation observed in power MOSFETs was caused by a single heavy ion. It was identified as a microdose effect and successfully characterized by several parameters extracted from experimental data. (author)

  3. High-energy heavy ion testing of VLSI devices for single event ...

    Indian Academy of Sciences (India)

    Unknown

    per describes the high-energy heavy ion radiation testing of VLSI devices for single event upset (SEU) ... The experimental set up employed to produce low flux of heavy ions viz. silicon ... through which they pass, leaving behind a wake of elec- ... for use in Bus Management Unit (BMU) and bulk CMOS ... was scheduled.

  4. On the single-ion Magnetic Anisotropy of the Rare-Earth Metals

    DEFF Research Database (Denmark)

    Kolmakova, N.P.; Tishin, A.M.; Bohr, Jakob

    1996-01-01

    The temperature dependences of the single-ion magnetic anisotropy constants for Tb and Dy metals are calculated in terms of the multipole moments of the rare-earth ions utilizing the available crystal-field parameters. The results are compared with the existing experimental data....

  5. U/Th dating by SHRIMP RG ion-microprobe mass spectrometry using single ion-exchange beads

    Science.gov (United States)

    Bischoff, J.L.; Wooden, J.; Murphy, F.; Williams, Ross W.

    2005-01-01

    We present a new analytical method for U-series isotopes using the SHRIMP RG (Sensitive High mass Resolution Ion MicroProbe) mass spectrometer that utilizes the preconcentration of the U-series isotopes from a sample onto a single ion-exchange bead. Ion-microprobe mass spectrometry is capable of producing Th ionization efficiencies in excess of 2%. Analytical precision is typically better than alpha spectroscopy, but not as good as thermal ionization mass spectroscopy (TIMS) and inductively coupled plasma multicollector mass spectrometry (ICP-MS). Like TIMS and ICP-MS the method allows analysis of small samples sizes, but also adds the advantage of rapidity of analysis. A major advantage of ion-microprobe analysis is that U and Th isotopes are analyzed in the same bead, simplifying the process of chemical separation. Analytical time on the instrument is ???60 min per sample, and a single instrument-loading can accommodate 15-20 samples to be analyzed in a 24-h day. An additional advantage is that the method allows multiple reanalyses of the same bead and that samples can be archived for reanalysis at a later time. Because the ion beam excavates a pit only a few ??m deep, the mount can later be repolished and reanalyzed numerous times. The method described of preconcentrating a low concentration sample onto a small conductive substrate to allow ion-microprobe mass spectrometry is potentially applicable to many other systems. Copyright ?? 2005 Elsevier Ltd.

  6. Lattice location of platinum ions implanted into single crystal zirconia and their annealing behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Cao, D X [Royal Melbourne Inst. of Tech., VIC (Australia); Sood, D K [Academia Sinica, Shanghai, SH (China). Shanghai Inst. of Nuclear Research; Brown, I G [Lawrence Berkeley Lab., CA (United States)

    1994-12-31

    Single crystal samples of (100) oriented cubic zirconia stabilised with 9.5 mol % yttria were implanted with platinum ions, using a metal vapour vacuum arc (MEVVA) high current ion implanter, to a nominal dose of 1x10{sup 17} ions/cm{sup 2}. The implanted samples were annealed isothermally in air ambient at 1200 deg C, from 1-24 hours. Rutherford Backscattering Spectrometry and Channeling (RBSC) of 2 MeV He ions are employed to determine depth distributions of ion damage, Pt ions and substitutionality of Pt ions before and after annealing. The damage behaviour, Pt migration and lattice location are discussed in terms of metastable phase formation and solid solubility considerations. 7 refs., 3 figs.

  7. Lattice location of platinum ions implanted into single crystal zirconia and their annealing behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Cao, D.X. [Royal Melbourne Inst. of Tech., VIC (Australia); Sood, D.K. [Academia Sinica, Shanghai, SH (China). Shanghai Inst. of Nuclear Research; Brown, I.G. [Lawrence Berkeley Lab., CA (United States)

    1993-12-31

    Single crystal samples of (100) oriented cubic zirconia stabilised with 9.5 mol % yttria were implanted with platinum ions, using a metal vapour vacuum arc (MEVVA) high current ion implanter, to a nominal dose of 1x10{sup 17} ions/cm{sup 2}. The implanted samples were annealed isothermally in air ambient at 1200 deg C, from 1-24 hours. Rutherford Backscattering Spectrometry and Channeling (RBSC) of 2 MeV He ions are employed to determine depth distributions of ion damage, Pt ions and substitutionality of Pt ions before and after annealing. The damage behaviour, Pt migration and lattice location are discussed in terms of metastable phase formation and solid solubility considerations. 7 refs., 3 figs.

  8. Visualisation of γH2AX Foci Caused by Heavy Ion Particle Traversal; Distinction between Core Track versus Non-Track Damage

    Science.gov (United States)

    Nakajima, Nakako Izumi; Brunton, Holly; Watanabe, Ritsuko; Shrikhande, Amruta; Hirayama, Ryoichi; Matsufuji, Naruhiro; Fujimori, Akira; Murakami, Takeshi; Okayasu, Ryuichi; Jeggo, Penny; Shibata, Atsushi

    2013-01-01

    Heavy particle irradiation produces complex DNA double strand breaks (DSBs) which can arise from primary ionisation events within the particle trajectory. Additionally, secondary electrons, termed delta-electrons, which have a range of distributions can create low linear energy transfer (LET) damage within but also distant from the track. DNA damage by delta-electrons distant from the track has not previously been carefully characterised. Using imaging with deconvolution, we show that at 8 hours after exposure to Fe (∼200 keV/µm) ions, γH2AX foci forming at DSBs within the particle track are large and encompass multiple smaller and closely localised foci, which we designate as clustered γH2AX foci. These foci are repaired with slow kinetics by DNA non-homologous end-joining (NHEJ) in G1 phase with the magnitude of complexity diminishing with time. These clustered foci (containing 10 or more individual foci) represent a signature of DSBs caused by high LET heavy particle radiation. We also identified simple γH2AX foci distant from the track, which resemble those arising after X-ray exposure, which we attribute to low LET delta-electron induced DSBs. They are rapidly repaired by NHEJ. Clustered γH2AX foci induced by heavy particle radiation cause prolonged checkpoint arrest compared to simple γH2AX foci following X-irradiation. However, mitotic entry was observed when ∼10 clustered foci remain. Thus, cells can progress into mitosis with multiple clusters of DSBs following the traversal of a heavy particle. PMID:23967070

  9. Single-ion polymer electrolyte membranes enable lithium-ion batteries with a broad operating temperature range.

    Science.gov (United States)

    Cai, Weiwei; Zhang, Yunfeng; Li, Jing; Sun, Yubao; Cheng, Hansong

    2014-04-01

    Conductive processes involving lithium ions are analyzed in detail from a mechanistic perspective, and demonstrate that single ion polymeric electrolyte (SIPE) membranes can be used in lithium-ion batteries with a wide operating temperature range (25-80 °C) through systematic optimization of electrodes and electrode/electrolyte interfaces, in sharp contrast to other batteries equipped with SIPE membranes that display appreciable operability only at elevated temperatures (>60 °C). The performance is comparable to that of batteries using liquid electrolyte of inorganic salt, and the batteries exhibit excellent cycle life and rate performance. This significant widening of battery operation temperatures coupled with the inherent flexibility and robustness of the SIPE membranes makes it possible to develop thin and flexible Li-ion batteries for a broad range of applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Tracking performance of a single-crystal and a polycrystalline diamond pixel-detector

    Energy Technology Data Exchange (ETDEWEB)

    Menasce, D.; et al.

    2013-06-01

    We present a comparative characterization of the performance of a single-crystal and a polycrystalline diamond pixel-detector employing the standard CMS pixel readout chips. Measurements were carried out at the Fermilab Test Beam Facility, FTBF, using protons of momentum 120 GeV/c tracked by a high-resolution pixel telescope. Particular attention was directed to the study of the charge-collection, the charge-sharing among adjacent pixels and the achievable position resolution. The performance of the single-crystal detector was excellent and comparable to the best available silicon pixel-detectors. The measured average detection-efficiency was near unity, ε = 0.99860±0.00006, and the position-resolution for shared hits was about 6 μm. On the other hand, the performance of the polycrystalline detector was hampered by its lower charge collection distance and the readout chip threshold. A new readout chip, capable of operating at much lower threshold (around 1 ke$-$), would be required to fully exploit the potential performance of the polycrystalline diamond pixel-detector.

  11. Expanding the Operational Limits of the Single-Point Impedance Diagnostic for Internal Temperature Monitoring of Lithium-ion Batteries

    International Nuclear Information System (INIS)

    Spinner, Neil S.; Love, Corey T.; Rose-Pehrsson, Susan L.; Tuttle, Steven G.

    2015-01-01

    Highlights: • Single-point impedance diagnostic technique demonstrated for lithium-ion batteries • Correlation between imaginary impedance and internal temperature determined • Instantaneous monitoring of commercial lithium-ion battery internal temperature • Expanded temperature range from −10°C up to 95°C • Non-invasive method useful for practical temperature monitoring of commercial cells - Abstract: Instantaneous internal temperature monitoring of a commercial 18650 LiCoO 2 lithium-ion battery was performed using a single-point EIS measurement. A correlation between the imaginary impedance, –Z imag , and internal temperature at 300 Hz was developed that was independent of the battery’s state of charge. An Arrhenius-type dependence was applied, and the activation energy for SEI ionic conductivity was found to be 0.13 eV. Two separate temperature-time experiments were conducted with different sequences of temperature, and single-point impedance tests at 300 Hz were performed to validate the correlation. Limitations were observed with the upper temperature range (68°C < T < 95°C), and consequently a secondary, empirical fit was applied for this upper range to improve accuracy. Average differences between actual and fit temperatures decreased around 3-7°C for the upper range with the secondary correlation. The impedance response at this frequency corresponded to the anode/SEI layer, and the SEI is reported to be thermally stable up to around 100°C, at which point decomposition may occur leading to battery deactivation and/or total failure. It is therefore of great importance to be able to track internal battery temperatures up to this critical point of 100°C, and this work demonstrates an expansion of the single-point EIS diagnostic to these elevated temperatures

  12. Single ionization of diatomic molecules by bare ion impact

    International Nuclear Information System (INIS)

    Purkait, M; Mandal, C R

    2014-01-01

    The molecular three-Coulomb wave model (M3CW) has been extensively used to study the double-differential ionization cross sections (DDCS) of diatomic molecules by the impact of bare ions at intermediate and high energies. In this model, the distortion of the initial channel by the incoming projectile is also included. The present DDCS results are found to be in good accord both with the experiment of Baran et al 2008 as well as with other theory

  13. Ferrimagnetic Properties of Bond Dilution Mixed Blume-Capel Model with Random Single-Ion Anisotropy

    International Nuclear Information System (INIS)

    Liu Lei; Yan Shilei

    2005-01-01

    We study the ferrimagnetic properties of spin 1/2 and spin-1 systems by means of the effective field theory. The system is considered in the framework of bond dilution mixed Blume-Capel model (BCM) with random single-ion anisotropy. The investigation of phase diagrams and magnetization curves indicates the existence of induced magnetic ordering and single or multi-compensation points. Special emphasis is placed on the influence of bond dilution and random single-ion anisotropy on normal or induced magnetic ordering states and single or multi-compensation points. Normal magnetic ordering states take on new phase diagrams with increasing randomness (bond and anisotropy), while anisotropy induced magnetic ordering states are always occurrence no matter whether concentration of anisotropy is large or small. Existence and disappearance of compensation points rely strongly on bond dilution and random single-ion anisotropy. Some results have not been revealed in previous papers and predicted by Neel theory of ferrimagnetism.

  14. Single and multiple object tracking using log-euclidean Riemannian subspace and block-division appearance model.

    Science.gov (United States)

    Hu, Weiming; Li, Xi; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen; Zhang, Zhongfei

    2012-12-01

    Object appearance modeling is crucial for tracking objects, especially in videos captured by nonstationary cameras and for reasoning about occlusions between multiple moving objects. Based on the log-euclidean Riemannian metric on symmetric positive definite matrices, we propose an incremental log-euclidean Riemannian subspace learning algorithm in which covariance matrices of image features are mapped into a vector space with the log-euclidean Riemannian metric. Based on the subspace learning algorithm, we develop a log-euclidean block-division appearance model which captures both the global and local spatial layout information about object appearances. Single object tracking and multi-object tracking with occlusion reasoning are then achieved by particle filtering-based Bayesian state inference. During tracking, incremental updating of the log-euclidean block-division appearance model captures changes in object appearance. For multi-object tracking, the appearance models of the objects can be updated even in the presence of occlusions. Experimental results demonstrate that the proposed tracking algorithm obtains more accurate results than six state-of-the-art tracking algorithms.

  15. A Single Phase Doubly Grounded Semi-Z-Source Inverter for Photovoltaic (PV Systems with Maximum Power Point Tracking (MPPT

    Directory of Open Access Journals (Sweden)

    Tofael Ahmed

    2014-06-01

    Full Text Available In this paper, a single phase doubly grounded semi-Z-source inverter with maximum power point tracking (MPPT is proposed for photovoltaic (PV systems. This proposed system utilizes a single-ended primary inductor (SEPIC converter as DC-DC converter to implement the MPPT algorithm for tracking the maximum power from a PV array and a single phase semi-Z-source inverter for integrating the PV with AC power utilities. The MPPT controller utilizes a fast-converging algorithm to track the maximum power point (MPP and the semi-Z-source inverter utilizes a nonlinear SPWM to produce sinusoidal voltage at the output. The proposed system is able to track the MPP of PV arrays and produce an AC voltage at its output by utilizing only three switches. Experimental results show that the fast-converging MPPT algorithm has fast tracking response with appreciable MPP efficiency. In addition, the inverter shows the minimization of common mode leakage current with its ground sharing feature and reduction of the THD as well as DC current components at the output during DC-AC conversion.

  16. Network type sp3 boron-based single-ion conducting polymer electrolytes for lithium ion batteries

    Science.gov (United States)

    Deng, Kuirong; Wang, Shuanjin; Ren, Shan; Han, Dongmei; Xiao, Min; Meng, Yuezhong

    2017-08-01

    Electrolytes play a vital role in modulating lithium ion battery performance. An outstanding electrolyte should possess both high ionic conductivity and unity lithium ion transference number. Here, we present a facile method to fabricate a network type sp3 boron-based single-ion conducting polymer electrolyte (SIPE) with high ionic conductivity and lithium ion transference number approaching unity. The SIPE was synthesized by coupling of lithium bis(allylmalonato)borate (LiBAMB) and pentaerythritol tetrakis(2-mercaptoacetate) (PETMP) via one-step photoinitiated in situ thiol-ene click reaction in plasticizers. Influence of kinds and content of plasticizers was investigated and the optimized electrolytes show both outstanding ionic conductivity (1.47 × 10-3 S cm-1 at 25 °C) and high lithium transference number of 0.89. This ionic conductivity is among the highest ionic conductivity exhibited by SIPEs reported to date. Its electrochemical stability window is up to 5.2 V. More importantly, Li/LiFePO4 cells with the prepared single-ion conducting electrolytes as the electrolyte as well as the separator display highly reversible capacity and excellent rate capacity under room temperature. It also demonstrates excellent long-term stability and reliability as it maintains capacity of 124 mA h g-1 at 1 C rate even after 500 cycles without obvious decay.

  17. Single-particle tracking of quantum dot-conjugated prion proteins inside yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Toshikazu; Kawai-Noma, Shigeko [Department of Biomolecular Engineering, Graduate School of Biosciences and Biotechnology, Tokyo Institute of Technology, B56, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501 (Japan); Pack, Chan-Gi [Cellular Informatics Laboratory, RIKEN Advanced Science Institute, Wako-shi, Saitama 351-0198 (Japan); Terajima, Hideki [Department of Biomolecular Engineering, Graduate School of Biosciences and Biotechnology, Tokyo Institute of Technology, B56, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501 (Japan); Yajima, Junichiro; Nishizaka, Takayuki [Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588 (Japan); Kinjo, Masataka [Laboratory of Molecular Cell Dynamics, Graduate School of Life Sciences, Hokkaido University, Sapporo 001-0021 (Japan); Taguchi, Hideki, E-mail: taguchi@bio.titech.ac.jp [Department of Biomolecular Engineering, Graduate School of Biosciences and Biotechnology, Tokyo Institute of Technology, B56, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501 (Japan)

    2011-02-25

    Research highlights: {yields} We develop a method to track a quantum dot-conjugated protein in yeast cells. {yields} We incorporate the conjugated quantum dot proteins into yeast spheroplasts. {yields} We track the motions by conventional or 3D tracking microscopy. -- Abstract: Yeast is a model eukaryote with a variety of biological resources. Here we developed a method to track a quantum dot (QD)-conjugated protein in the budding yeast Saccharomyces cerevisiae. We chemically conjugated QDs with the yeast prion Sup35, incorporated them into yeast spheroplasts, and tracked the motions by conventional two-dimensional or three-dimensional tracking microscopy. The method paves the way toward the individual tracking of proteins of interest inside living yeast cells.

  18. Single-particle tracking of quantum dot-conjugated prion proteins inside yeast cells

    International Nuclear Information System (INIS)

    Tsuji, Toshikazu; Kawai-Noma, Shigeko; Pack, Chan-Gi; Terajima, Hideki; Yajima, Junichiro; Nishizaka, Takayuki; Kinjo, Masataka; Taguchi, Hideki

    2011-01-01

    Research highlights: → We develop a method to track a quantum dot-conjugated protein in yeast cells. → We incorporate the conjugated quantum dot proteins into yeast spheroplasts. → We track the motions by conventional or 3D tracking microscopy. -- Abstract: Yeast is a model eukaryote with a variety of biological resources. Here we developed a method to track a quantum dot (QD)-conjugated protein in the budding yeast Saccharomyces cerevisiae. We chemically conjugated QDs with the yeast prion Sup35, incorporated them into yeast spheroplasts, and tracked the motions by conventional two-dimensional or three-dimensional tracking microscopy. The method paves the way toward the individual tracking of proteins of interest inside living yeast cells.

  19. Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

    2011-07-01

    Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

  20. Radial dependence of biological response of spores of Bacillus subtilis around tracks of heavy ions

    International Nuclear Information System (INIS)

    Facius, R.; Buecker, H.; Reitz, G.; Schaefer, M.

    1978-01-01

    Results on the biological action of heavy cosmic particles from the Biostack I and II experiments had been reported at the two preceeding symposia on microdosimetry. Analysis of these results with respect to spores of Bacillus subtilis indicated that the range of inactivation by a single heavy ion extended to larger impact parameters than to be expected from delta-ray dose only. Improved experimental techniques, as described at the last symposium, were successfully applied for the evaluation of the latest Biostack III experiment during the Apollo-Soyuz Test Project (ASTP). These techniques allowed the determination of the impact parameters with an accuracy of down to +-0.2 μm, which is well below the size of a spore. Results of the ASTP experiment will be presented concerning the physical composition of the radiation field and the biological response of the spores in dependence on the impact parameter. These results confirm the previous findings insofar as inactivation of spores reaches out to about 4-5 μm. This finding will be discussed together with results from other Biostack test objects. Comparative accelerator experiments with Bacillus subtilis spores are presented in an additional paper

  1. Counter-ions at single charged wall: Sum rules.

    Science.gov (United States)

    Samaj, Ladislav

    2013-09-01

    For inhomogeneous classical Coulomb fluids in thermal equilibrium, like the jellium or the two-component Coulomb gas, there exists a variety of exact sum rules which relate the particle one-body and two-body densities. The necessary condition for these sum rules is that the Coulomb fluid possesses good screening properties, i.e. the particle correlation functions or the averaged charge inhomogeneity, say close to a wall, exhibit a short-range (usually exponential) decay. In this work, we study equilibrium statistical mechanics of an electric double layer with counter-ions only, i.e. a globally neutral system of equally charged point-like particles in the vicinity of a plain hard wall carrying a fixed uniform surface charge density of opposite sign. At large distances from the wall, the one-body and two-body counter-ion densities go to zero slowly according to the inverse-power law. In spite of the absence of screening, all known sum rules are shown to hold for two exactly solvable cases of the present system: in the weak-coupling Poisson-Boltzmann limit (in any spatial dimension larger than one) and at a special free-fermion coupling constant in two dimensions. This fact indicates an extended validity of the sum rules and provides a consistency check for reasonable theoretical approaches.

  2. Convergence of lateral dynamic measurements in the plasma membrane of live cells from single particle tracking and STED-FCS

    DEFF Research Database (Denmark)

    Lagerholm, B. Christoffer; Andrade, Débora M.; Clausen, Mathias P.

    2017-01-01

    Fluorescence correlation spectroscopy (FCS) in combination with the super-resolution imaging method STED (STED-FCS), and single-particle tracking (SPT) are able to directly probe the lateral dynamics of lipids and proteins in the plasma membrane of live cells at spatial scales much below the diff...

  3. Research on generation mechanism of single event transient current generated in the semiconductor using ion accelerator

    International Nuclear Information System (INIS)

    Hirao, Toshio

    2007-01-01

    Single-event upset (SEU) is triggered when an amount of electric charges induced by energetic ion incidence exceeds a value known as a critical charge in a very short time period. Therefore, accurate evaluation of electric charge and understanding of basic mechanism of SEU are necessary for the improvement of SEU torrance of electronic devices. In this paper, the collected charges for the single event transient current induced on semiconductor by heavy ion microbeams, and application to use microbeam for single event studies are presented. (author)

  4. Exchange interaction of strongly anisotropic tripodal erbium single-ion magnets with metallic surfaces

    DEFF Research Database (Denmark)

    Dreiser, Jan; Wäckerlin, Christian; Ali, Md. Ehesan

    2014-01-01

    We present a comprehensive study of Er(trensal) single-ion magnets deposited in ultrahigh vacuum onto metallic surfaces. X-ray photoelectron spectroscopy reveals that the molecular structure is preserved after sublimation, and that the molecules are physisorbed on Au(111) while they are chemisorbed...... on a Ni thin film on Cu(100) single-crystalline surfaces. X-ray magnetic circular dichroism (XMCD) measurements performed on Au(111) samples covered with molecular monolayers held at temperatures down to 4 K suggest that the easy axes of the strongly anisotropic molecules are randomly oriented...... pathways toward optical addressing of surface-deposited single-ion magnets....

  5. Calculation of electronic stopping power along glancing swift heavy ion tracks in perovskites using ab initio electron density data

    Energy Technology Data Exchange (ETDEWEB)

    Osmani, O; Duvenbeck, A; Akcoeltekin, E; Meyer, R; Schleberger, M [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany); Lebius, H [CIMAP, blvd Henri Becquerel, 14070 Caen (France)], E-mail: marika.schleberger@uni-due.de

    2008-08-06

    In recent experiments the irradiation of insulators of perovskite type with swift (E{approx}100 MeV) heavy ions under glancing incidence has been shown to provide a unique means to generate periodically arranged nanodots at the surface. The physical origin of these patterns has been suggested as stemming from a highly anisotropic electron density distribution within the bulk. In order to show the relevance of the electron density distribution of the target we present a model calculation for the system Xe{sup 23+} {yields} SrTiO{sub 3} that is known to produce the aforementioned surface modifications. On the basis of the Lindhard model of electronic stopping, we employ highly-resolved ab initio electron density data to describe the conversion of kinetic energy into excitation energy along the ion track. The primary particle dynamics are obtained via integration of the Newtonian equations of motion that are governed by a space- and time-dependent frictional force originating from Lindhard stopping. The analysis of the local electronic stopping power along the ion track reveals a pronounced periodic structure. The periodicity length varies strongly with the particular choice of the polar angle of incidence and is directly correlated to the experimentally observed formation of periodic nanodots at insulator surfaces.

  6. Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

    Energy Technology Data Exchange (ETDEWEB)

    Crespillo, M.L., E-mail: mcrespil@utk.edu [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Department of Materials Science & Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Agulló-López, F., E-mail: fal@uam.es [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Zucchiatti, A. [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain)

    2017-03-01

    Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO{sub 3} crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

  7. Geometry modeling of single track cladding deposited by high power diode laser with rectangular beam spot

    Science.gov (United States)

    Liu, Huaming; Qin, Xunpeng; Huang, Song; Hu, Zeqi; Ni, Mao

    2018-01-01

    This paper presents an investigation on the relationship between the process parameters and geometrical characteristics of the sectional profile for the single track cladding (STC) deposited by High Power Diode Laser (HPDL) with rectangle beam spot (RBS). To obtain the geometry parameters, namely cladding width Wc and height Hc of the sectional profile, a full factorial design (FFD) of experiment was used to conduct the experiments with a total of 27. The pre-placed powder technique has been employed during laser cladding. The influence of the process parameters including laser power, powder thickness and scanning speed on the Wc and Hc was analyzed in detail. A nonlinear fitting model was used to fit the relationship between the process parameters and geometry parameters. And a circular arc was adopted to describe the geometry profile of the cross-section of STC. The above models were confirmed by all the experiments. The results indicated that the geometrical characteristics of the sectional profile of STC can be described as the circular arc, and the other geometry parameters of the sectional profile can be calculated only using Wc and Hc. Meanwhile, the Wc and Hc can be predicted through the process parameters.

  8. Uncovering homo-and hetero-interactions on the cell membrane using single particle tracking approaches

    International Nuclear Information System (INIS)

    Torreno-Pina, Juan A; Manzo, Carlo; Garcia-Parajo, Maria F

    2016-01-01

    The plasma membrane of eukaryotic cells is responsible for a myriad of functions that regulate cell physiology and plays a crucial role in a multitude of processes that include adhesion, migration, signaling recognition and cell–cell communication. This is accomplished by specific interactions between different membrane components such as lipids and proteins on the lipid bilayer but also through interactions with the underlying cortical actin cytoskeleton on the intracellular side and the glycocalyx matrix in close proximity to the extracellular side. Advanced biophysical techniques, including single particle tracking (SPT) have revealed that the lateral diffusion of molecular components on the plasma membrane represents a landmark manifestation of such interactions. Indeed, by studying changes in the diffusivity of individual membrane molecules, including sub-diffusion, confined diffusion and/or transient arrest of molecules in membrane compartments, it has been possible to gain insight on the nature of molecular interactions and to infer on its functional role for cell response. In this review, we will revise some exciting results where SPT has been crucial to reveal homo- and hetero-interactions on the cell membrane. (paper)

  9. An Interactive Microsoft(registered tm) Excel Program for Tracking a Single Evaporating Droplet in Crossflow

    Science.gov (United States)

    Liew, K. H.; Urip, E.; Yang, S. L.; Marek, C. J.

    2004-01-01

    Droplet interaction with a high temperature gaseous crossflow is important because of its wide application in systems involving two phase mixing such as in combustion requiring quick mixing of fuel and air with the reduction of pollutants and for jet mixing in the dilution zone of combustors. Therefore, the focus of this work is to investigate dispersion of a two-dimensional atomized and evaporating spray jet into a two-dimensional crossflow. An interactive Microsoft Excel program for tracking a single droplet in crossflow that has previously been developed will be modified to include droplet evaporation computation. In addition to the high velocity airflow, the injected droplets are also subjected to combustor temperature and pressure that affect their motion in the flow field. Six ordinary differential equations are then solved by 4th-order Runge-Kutta method using Microsoft Excel software. Microsoft Visual Basic programming and Microsoft Excel macrocode are used to produce the data and plot graphs describing the droplet's motion in the flow field. This program computes and plots the data sequentially without forcing the user to open other types of plotting programs. A user's manual on how to use the program is included.

  10. Single bacteria movement tracking by online microscopy--a proof of concept study.

    Directory of Open Access Journals (Sweden)

    Andreas Ziegler

    Full Text Available In this technical report we demonstrate a low-cost online unit allowing movement tracking of flagellated bacteria on a single-cell level during fermentation processes. The system's ability to distinguish different metabolic states (viability of bacteria by movement velocity was investigated. A flow-through cuvette with automatically adjustable layer thickness was developed. The cuvette can be used with most commercially available laboratory microscopes equipped with 40× amplification and a digital camera. In addition, an automated sample preparation unit and a software module was developed measuring size, moved distance, and speed of bacteria. In a proof of principle study the movement velocities of Bacillus amyloliquefaciens FZB42 during three batch fermentation processes were investigated. In this process the bacteria went through different metabolic states, vegetative growth, diauxic shift, vegetative growth after diauxic shift, and sporulation. It was shown that the movement velocities during the different metabolic states significantly differ from each other. Therefore, the described setup has the potential to be used as a bacteria viability monitoring tool. In contrast to some other techniques, such as electro-optical techniques, this method can even be used in turbid production media.

  11. Single event simulation for memories using accelerated ions

    International Nuclear Information System (INIS)

    Sakagawa, Y.; Shiono, N.; Mizusawa, T.; Sekiguchi, M.; Sato, K.; Sugai, I.; Hirao, Y.; Nishimura, J.; Hattori, T.

    1987-01-01

    To evaluate the error immunity of the LSI memories from cosmic rays in space, an irradiation test using accelerated heavy ions is performed. The sensitive regions for 64 K DRAM (Dynamic Random Access Memory) and 4 K SRAM (Static Random Access Memory) are determined from the irradiation test results and the design parameters of the devices. The observed errors can be classified into two types. One is the direct ionization type and the other is the recoil produced error type. Sensitive region is determined for the devices. Error rate estimation methods for both types are proposed and applied to those memories used in space. The error rate of direct ionization exceeds the recoil type by 2 or 3 orders. And the direct ionization is susceptible to shield thickness. (author)

  12. Pyramidal pits created by single highly charged ions in BaF2 single crystals

    International Nuclear Information System (INIS)

    El-Said, A. S.; Heller, R.; Facsko, S.; Aumayr, F.

    2010-01-01

    In various insulators, the impact of individual slow highly charged ions (eV-keV) creates surface nanostructures, whose size depends on the deposited potential energy. Here we report on the damage created on a cleaved BaF 2 (111) surface by irradiation with 4.5xq keV highly charged xenon ions from a room-temperature electron-beam ion trap. Up to charge states q=36, no surface topographic changes on the BaF 2 surface are observed by scanning force microscopy. The hidden stored damage, however, can be made visible using the technique of selective chemical etching. Each individual ion impact develops into a pyramidal etch pits, as can be concluded from a comparison of the areal density of observed etch pits with the applied ion fluence (typically 10 8 ions/cm 2 ). The dimensional analysis of the measured pits reveals the significance of the deposited potential energy in the creation of lattice distortions/defects in BaF 2 .

  13. Coupled acoustic-gravity field for dynamic evaluation of ion exchange with a single resin bead.

    Science.gov (United States)

    Kanazaki, Takahiro; Hirawa, Shungo; Harada, Makoto; Okada, Tetsuo

    2010-06-01

    A coupled acoustic-gravity field is efficient for entrapping a particle at the position determined by its acoustic properties rather than its size. This field has been applied to the dynamic observation of ion-exchange reactions occurring in a single resin bead. The replacement of counterions in an ion-exchange resin induces changes in its acoustic properties, such as density and compressibility. Therefore, we can visually trace the advancement of an ion-exchange reaction as a time change in the levitation position of a resin bead entrapped in the field. Cation-exchange reactions occurring in resin beads with diameters of 40-120 microm are typically completed within 100-200 s. Ion-exchange equilibrium or kinetics is often evaluated with off-line chemical analyses, which require a batch amount of ion exchangers. Measurements with a single resin particle allow us to evaluate ion-exchange dynamics and kinetics of ions including those that are difficult to measure by usual off-line analyses. The diffusion properties of ions in resins have been successfully evaluated from the time change in the levitation positions of resin beads.

  14. Single event effects induced by 15.14 MeV/u 136Xe ions

    International Nuclear Information System (INIS)

    Hou Mingdong; Zhang Qingxiang; Liu Jie; Wang Zhiguang; Jin Yunfan; Zhu Zhiyong; Zhen Honglou; Liu Changlong; Chen Xiaoxi; Wei Xinguo; Zhang Lin; Fan Youcheng; Zhu Zhourong; Zhang Yiting

    2002-01-01

    Single event effects induced by 15.14 MeV/u 136 Xe ions in different batches of 32k x 8 bits static random access memory are studied. The incident angle dependences of the cross sections for single event upset and single event latch up are presented. The SEE cross sections are plotted versus energy loss instead of linear energy transfer value in sensitive region. The depth of sensitive volume and thickness of 'dead' layer above the sensitive volume are estimated

  15. Time-Lapse Monitoring of DNA Damage Colocalized With Particle Tracks in Single Living Cells

    Energy Technology Data Exchange (ETDEWEB)

    McFadden, Conor H. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hallacy, Timothy M. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Physics and Astronomy, Rice University, Houston, Texas (United States); Flint, David B. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Graduate School of Biomedical Sciences, The University of Texas, Houston, Texas (United States); Granville, Dal A. [Department of Medical Physics, The Ottawa Hospital Cancer Centre, Ottawa, Ontario (Canada); Asaithamby, Aroumougame [Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Centre, Dallas, Texas (United States); Sahoo, Narayan [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Akselrod, Mark S. [Crystal Growth Division, Landauer, Inc, Stillwater, Oklahoma (United States); Sawakuchi, Gabriel O., E-mail: gsawakuchi@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Graduate School of Biomedical Sciences, The University of Texas, Houston, Texas (United States)

    2016-09-01

    Purpose: Understanding the DNA damage and repair induced by hadron therapy (HT) beams is crucial for developing novel strategies to maximize the use of HT beams to treat cancer patients. However, spatiotemporal studies of DNA damage and repair for beam energies relevant to HT have been challenging. We report a technique that enables spatiotemporal measurement of radiation-induced damage in live cells and colocalization of this damage with charged particle tracks over a broad range of clinically relevant beam energies. The technique uses novel fluorescence nuclear track detectors with fluorescence confocal laser scanning microscopy in the beam line to visualize particle track traversals within the subcellular compartments of live cells within seconds after injury. Methods and Materials: We designed and built a portable fluorescence confocal laser scanning microscope for use in the beam path, coated fluorescence nuclear track detectors with fluorescent-tagged live cells (HT1080 expressing enhanced green fluorescent protein tagged to XRCC1, a single-strand break repair protein), placed the entire assembly into a proton therapy beam line, and irradiated the cells with a fluence of ∼1 × 10{sup 6} protons/cm{sup 2}. Results: We successfully obtained confocal images of proton tracks and foci of DNA single-strand breaks immediately after irradiation. Conclusions: This technique represents an innovative method for analyzing biological responses in any HT beam line at energies and dose rates relevant to therapy. It allows precise determination of the number of tracks traversing a subcellular compartment and monitoring the cellular damage therein, and has the potential to measure the linear energy transfer of each track from therapeutic beams.

  16. Imaging large cohorts of single ion channels and their activity

    Directory of Open Access Journals (Sweden)

    Katia eHiersemenzel

    2013-09-01

    Full Text Available As calcium is the most important signaling molecule in neurons and secretory cells, amongst many other cell types, it follows that an understanding of calcium channels and their regulation of exocytosis is of vital importance. Calcium imaging using calcium dyes such as Fluo3, or FRET-based dyes that have been used widely has provided invaluable information, which combined with modeling has estimated the sub-types of channels responsible for triggering the exocytotic machinery as well as inferences about the relative distances away from vesicle fusion sites these molecules adopt. Importantly, new super-resolution microscopy techniques, combined with novel Ca2+ indicators and imaginative imaging approaches can now define directly the nanoscale locations of very large cohorts of single channel molecules in relation to single vesicles. With combinations of these techniques the activity of individual channels can be visualized and quantified using novel Ca2+ indicators. Fluorescently labeled specific channel toxins can also be used to localize endogenous assembled channel tetramers. Fluorescence lifetime imaging microscopy and other single-photon-resolution spectroscopic approaches offer the possibility to quantify protein-protein interactions between populations of channels and the SNARE protein machinery for the first time. Together with simultaneous electrophysiology, this battery of quantitative imaging techniques has the potential to provide unprecedented detail describing the locations, dynamic behaviours, interactions and conductance activities of many thousands of channel molecules and vesicles in living cells.

  17. Evaluation of single tracks of 17-4PH steel manufactured at different power densities and scanning speeds by selective laser melting

    Directory of Open Access Journals (Sweden)

    Makoana, N. W.

    2016-11-01

    Full Text Available In Selective Laser Melting, the initial units produced are single tracks that overlap to create a single layer; from the sequence of layers, a 3D object is manufactured. The properties of the parts produced by SLM depend heavily on the properties of each single track and each layer formed by these tracks. This study evaluates the effect of processing parameters on the geometrical characteristics of single tracks manufactured from 17-4PH stainless steel powder. A single-mode continuous-wave ytterbium fibre laser was used to manufacture single tracks at laser powers in the range of 100-300 W with a constant spot size of ∼80μm. The single tracks produced were subjected to standard metallographic preparation techniques for further analysis with an optical microscope. Deep molten pool shapes were observed at low scan speeds, while shallow molten pool shapes were observed at high scan speeds. At higher laser power densities, under-cutting and humping effects were also observed. The dimensions of single tracks processed without powder generally decrease with increasing scan speed at constant laser power. However, the geometrical features of the single tracks processed with powder revealed pronounced irregularities believed to be caused by non-homogeneity in the deposited powder layer.

  18. A Quality Evaluation of Single and Multiple Camera Calibration Approaches for an Indoor Multi Camera Tracking System

    Directory of Open Access Journals (Sweden)

    M. Adduci

    2014-06-01

    Full Text Available Human detection and tracking has been a prominent research area for several scientists around the globe. State of the art algorithms have been implemented, refined and accelerated to significantly improve the detection rate and eliminate false positives. While 2D approaches are well investigated, 3D human detection and tracking is still an unexplored research field. In both 2D/3D cases, introducing a multi camera system could vastly expand the accuracy and confidence of the tracking process. Within this work, a quality evaluation is performed on a multi RGB-D camera indoor tracking system for examining how camera calibration and pose can affect the quality of human tracks in the scene, independently from the detection and tracking approach used. After performing a calibration step on every Kinect sensor, state of the art single camera pose estimators were evaluated for checking how good the quality of the poses is estimated using planar objects such as an ordinate chessboard. With this information, a bundle block adjustment and ICP were performed for verifying the accuracy of the single pose estimators in a multi camera configuration system. Results have shown that single camera estimators provide high accuracy results of less than half a pixel forcing the bundle to converge after very few iterations. In relation to ICP, relative information between cloud pairs is more or less preserved giving a low score of fitting between concatenated pairs. Finally, sensor calibration proved to be an essential step for achieving maximum accuracy in the generated point clouds, and therefore in the accuracy of the produced 3D trajectories, from each sensor.

  19. Hierarchically porous carbon membranes containing designed nanochannel architectures obtained by pyrolysis of ion-track etched polyimide

    Energy Technology Data Exchange (ETDEWEB)

    Muench, Falk, E-mail: muench@ca.tu-darmstadt.de [Department of Material- and Geoscience, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Seidl, Tim; Rauber, Markus [Department of Material- and Geoscience, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Material Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Peter, Benedikt; Brötz, Joachim [Department of Material- and Geoscience, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Krause, Markus; Trautmann, Christina [Department of Material- and Geoscience, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Material Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Roth, Christina [Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin (Germany); Katusic, Stipan [Evonik Industries AG, Rodenbacher Chaussee 4, 63457 Hanau (Germany); Ensinger, Wolfgang [Department of Material- and Geoscience, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany)

    2014-12-15

    Well-defined, porous carbon monoliths are highly promising materials for electrochemical applications, separation, purification and catalysis. In this work, we present an approach allowing to transfer the remarkable degree of synthetic control given by the ion-track etching technology to the fabrication of carbon membranes with porosity structured on multiple length scales. The carbonization and pore formation processes were examined with Raman, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements, while model experiments demonstrated the viability of the carbon membranes as catalyst support and pollutant adsorbent. Using ion-track etching, specifically designed, continuous channel-shaped pores were introduced into polyimide foils with precise control over channel diameter, orientation, density and interconnection. At a pyrolysis temperature of 950 °C, the artificially created channels shrunk in size, but their shape was preserved, while the polymer was transformed to microporous, amorphous carbon. Channel diameters ranging from ∼10 to several 100 nm could be achieved. The channels also gave access to previously closed micropore volume. Substantial surface increase was realized, as it was shown by introducing a network consisting of 1.4 × 10{sup 10} channels per cm{sup 2} of 30 nm diameter, which more than tripled the mass-normalized surface of the pyrolytic carbon from 205 m{sup 2} g{sup −1} to 732 m{sup 2} g{sup −1}. At a pyrolysis temperature of 3000 °C, membranes consisting of highly ordered graphite were obtained. In this case, the channel shape was severely altered, resulting in a pronounced conical geometry in which the channel diameter quickly decreased with increasing distance to the membrane surface. - Highlights: • Pyrolysis of ion-track etched polyimide yields porous carbon membranes. • Hierarchic porosity: continuous nanochannels embedded in a microporous carbon matrix.

  20. Hierarchically porous carbon membranes containing designed nanochannel architectures obtained by pyrolysis of ion-track etched polyimide

    International Nuclear Information System (INIS)

    Muench, Falk; Seidl, Tim; Rauber, Markus; Peter, Benedikt; Brötz, Joachim; Krause, Markus; Trautmann, Christina; Roth, Christina; Katusic, Stipan; Ensinger, Wolfgang

    2014-01-01

    Well-defined, porous carbon monoliths are highly promising materials for electrochemical applications, separation, purification and catalysis. In this work, we present an approach allowing to transfer the remarkable degree of synthetic control given by the ion-track etching technology to the fabrication of carbon membranes with porosity structured on multiple length scales. The carbonization and pore formation processes were examined with Raman, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements, while model experiments demonstrated the viability of the carbon membranes as catalyst support and pollutant adsorbent. Using ion-track etching, specifically designed, continuous channel-shaped pores were introduced into polyimide foils with precise control over channel diameter, orientation, density and interconnection. At a pyrolysis temperature of 950 °C, the artificially created channels shrunk in size, but their shape was preserved, while the polymer was transformed to microporous, amorphous carbon. Channel diameters ranging from ∼10 to several 100 nm could be achieved. The channels also gave access to previously closed micropore volume. Substantial surface increase was realized, as it was shown by introducing a network consisting of 1.4 × 10 10 channels per cm 2 of 30 nm diameter, which more than tripled the mass-normalized surface of the pyrolytic carbon from 205 m 2  g −1 to 732 m 2  g −1 . At a pyrolysis temperature of 3000 °C, membranes consisting of highly ordered graphite were obtained. In this case, the channel shape was severely altered, resulting in a pronounced conical geometry in which the channel diameter quickly decreased with increasing distance to the membrane surface. - Highlights: • Pyrolysis of ion-track etched polyimide yields porous carbon membranes. • Hierarchic porosity: continuous nanochannels embedded in a microporous carbon matrix. • Freely adjustable meso- or

  1. Improved generation of single nitrogen-vacancy centers in diamond by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Naydenov, Boris; Beck, Johannes; Steiner, Matthias; Balasubramanian, Gopalakrishnan; Jelezko, Fedor; Wrachtrup, Joerg [3. Institute of Physics, University of Stuttgart (Germany); Richter, Vladimir; Kalish, Rafi [Solid State Institute, Technion City, Haifa (Israel); Achard, Jocelyn [Laboratoire d' Ingenieurie des Materiaux et des Hautes Pressions, CNRS, Villetaneuse (France)

    2010-07-01

    Nitrogen-vacancy (NV) centers in diamond have recently attracted the attention of many research groups due to their possible application as quantum bits (qubits), ultra low magnetic field sensors and single photon sources. These color centers can be produced by nitrogen ion implantation, although the yield is usually below 5 % at low ion energies. Here we report an increase of the NV production efficiency by subsequently implanting carbon ions in the area of implanted nitrogen ions. This method improves the production yield by more than 50 %. We also show that very low nitrogen concentration (below 0.1 ppb) in diamond can be determined by converting the intrinsic nitrogen atoms to single NV centers and detecting the latter using a confocal microscope.

  2. Laser spectroscopic investigation of singly and doubly charged thorium ions

    Energy Technology Data Exchange (ETDEWEB)

    Thielking, Johannes; Meier, David-Marcel; Glowacki, Przemyslaw; Okhapkin, Maksim V.; Peik, Ekkehard [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2017-07-01

    The {sup 229}Th isotope possesses a unique, low-energy nuclear isomeric state at about 7.8(5) eV. This fact has stimulated the development of novel ideas in the borderland between atomic and nuclear physics, for example the use as an optical nuclear clock. Since the required precise information on the isomer energy is not yet available, it is intensely searched for using different experimental approaches. For the excitation of the nuclear isomer via electronic bridge or NEET processes, we plan to use two-photon laser excitation of high-lying electronic levels in Th{sup +}. We recently expanded our search range to higher energies and measured 38 previously unknown energy levels in the range from 7.8 eV to 8.7 eV. We also prepare to study the nuclear structure of the isomeric state in cooperation with the Maier-Leibnitz-Laboratorium at LMU Munich, using trapped recoil ions, where the isomeric state is populated via α-decay from {sup 233}U. For this purpose we investigate the hyperfine structure of suitable transitions of Th{sup 2+}.

  3. Numerical simulation of single bubbles rising through subchannels with interface tracking method

    International Nuclear Information System (INIS)

    Hiroyuki Yoshida; Takuji Nagayoshi; Hidesada Tamai; Tazuyuki Takase; Hajime Akimoto

    2005-01-01

    Full text of publication follows: Although the sub-channel codes are used for the thermal-hydraulic analysis of fuel bundles in nuclear reactors from the former, many compositions and empirical equations based on experimental results are needed to predict the two-phase flow behavior in details. When there are no experimental data such as the reduced-moderation light water reactor (RMWR) which is studied by the Japan Atomic Energy Research Institute (JAERI), therefore, it is very difficult to obtain highly precise predictions. The RMWR core has remarkably narrow gap spacing between fuel rods (i.e., around 1 mm) which are arranged at a triangular tight-lattice configuration. To evaluate the feasibility and to optimize the thermal design of the RMWR core, a full-scale bundle test is required. However, several systematic full-scale tests are difficult to perform during an initial design phase from economic and temporal reason. Thus, we made a plan to develop a mechanistic BT model to evaluate the effects of the geometry configuration by a two-phase flow numerical simulation. In the plan of the mechanistic BT model development, three dimensional two-phase flow simulation codes with the interface tracking method, the moving particle semi-implicit method and the advanced two-fluid model are developed. In this study, as a part of this model development, detailed two-phase flow simulation code using interface tracking method (named TPFIT) is developed. In this paper, the results of TPFIT code with the advanced interface tracking method applied to single bubbles behavior through subchannels) to verify TPFIT code performance in complicated flow channel as rod bundles. In the simulation, the flow channel is composed of a square duct and four tubes with outside diameters D = 12 mm. The width and height of the duct are 27.2 mm and 192 mm, respectively. In the flow channel, the tubes are used to simulate fuel rods. One center subchannel and four periphery subchannels exist in the

  4. Developing new optical imaging techniques for single particle and molecule tracking in live cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Differential interference contrast (DIC) microscopy is a far-field as well as wide-field optical imaging technique. Since it is non-invasive and requires no sample staining, DIC microscopy is suitable for tracking the motion of target molecules in live cells without interfering their functions. In addition, high numerical aperture objectives and condensers can be used in DIC microscopy. The depth of focus of DIC is shallow, which gives DIC much better optical sectioning ability than those of phase contrast and dark field microscopies. In this work, DIC was utilized to study dynamic biological processes including endocytosis and intracellular transport in live cells. The suitability of DIC microscopy for single particle tracking in live cells was first demonstrated by using DIC to monitor the entire endocytosis process of one mesoporous silica nanoparticle (MSN) into a live mammalian cell. By taking advantage of the optical sectioning ability of DIC, we recorded the depth profile of the MSN during the endocytosis process. The shape change around the nanoparticle due to the formation of a vesicle was also captured. DIC microscopy was further modified that the sample can be illuminated and imaged at two wavelengths simultaneously. By using the new technique, noble metal nanoparticles with different shapes and sizes were selectively imaged. Among all the examined metal nanoparticles, gold nanoparticles in rod shapes were found to be especially useful. Due to their anisotropic optical properties, gold nanorods showed as diffraction-limited spots with disproportionate bright and dark parts that are strongly dependent on their orientation in the 3D space. Gold nanorods were developed as orientation nanoprobes and were successfully used to report the self-rotation of gliding microtubules on kinesin coated substrates. Gold nanorods were further used to study the rotational motions of cargoes during the endocytosis and intracellular transport processes in live mammalian

  5. Ion beam synthesis of buried single crystal erbium silicide

    International Nuclear Information System (INIS)

    Golanski, A.; Feenstra, R.; Galloway, M.D.; Park, J.L.; Pennycook, S.J.; Harmon, H.E.; White, C.W.

    1990-01-01

    High doses (10 16 --10 17 /cm 2 ) of 170 keV Er + were implanted into single-crystal left-angle 111 right-angle Si at implantation temperatures between 350 degree C and 520 degree C. Annealing at 800 degree C in vacuum following the implant, the growth and coalescence of ErSi 2 precipitates leads to a buried single crystalline ErSi 2 layer. This has been studied using Rutherford backscattering/channeling, X-ray diffraction, cross-sectional TEM and resistance versus temperature measurements. Samples implanted at 520 degree C using an Er dose of 7 x 10 16 /cm 2 and thermally annealed were subsequently used as seeds for the mesoepitaxial growth of the buried layer during a second implantation and annealing process. Growth occurs meso-epitaxially along both interfaces through beam induced, defect mediated mobility of Er atoms. The crystalline quality of the ErSi 2 layer strongly depends on the temperature during the second implantation. 12 refs., 4 figs

  6. Effect of 120 MeV Ag{sup 9+} ion irradiation of YCOB single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Arun Kumar, R., E-mail: rarunpsgtech@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600 025 (India); Department of Basic Sciences - Physics Division, PSG College of Technology, Coimbatore 641 004 (India); Dhanasekaran, R. [Crystal Growth Centre, Anna University, Chennai 600 025 (India)

    2012-09-15

    Single crystals of yttrium calcium oxy borate (YCOB) grown from boron-tri-oxide flux were subjected to swift heavy ion irradiation using silver Ag{sup 9+} ions from the 15 UD Pelletron facility at Inter University Accelerator Center, New Delhi. The crystals were irradiated at 1 Multiplication-Sign 10{sup 13}, 5 Multiplication-Sign 10{sup 13} and 1 Multiplication-Sign 10{sup 14} ions/cm{sup 2} fluences at room temperature and with 5 Multiplication-Sign 10{sup 13} ions/cm{sup 2} fluence at liquid nitrogen temperature. The pristine and the irradiated samples were characterized by glancing angle X-ray diffraction, UV-Vis-NIR and photoluminescence studies. From the characterization studies performed on the samples, it is inferred that the crystals irradiated at liquid nitrogen temperature had fewer defects compared to the crystals irradiated at room temperature and the defects increased when the ion fluence was increased at room temperature.

  7. Pilot production of track etch membranes (TEMS) using heavy ion beam scanner

    International Nuclear Information System (INIS)

    Nair, J.P.; Surendran, P.; Sparrow, Hillary; Ninawe, N.G.; Bhagwat, P.V.; Acharya, N.; Kulshreshta, V.; Rajesh Kumar; Vijay, Y.K.; Kurup, M.B.

    2005-01-01

    Various methods for making TEMs were conducted at Pelletron Accelerator Facility. The technique for production using ion beam scattering was also established. This is an effort to make TEMs on pilot basis at BARC- TIFR Pelletron Accelerator using Heavy Ion Beam Scanner till large rolling mechanism is implemented

  8. Sub-Poissonian statistics of quantum jumps in single molecule or atomic ion

    International Nuclear Information System (INIS)

    Osad'ko, I.S.; Gus'kov, D.N.

    2007-01-01

    A theory for statistics of quantum jumps in single molecule or ion driven by continues wave laser field is developed. These quantum jumps can relate to nonradiative singlet-triplet transitions in a molecule or to on → off jumps in a single ion with shelving processes. Distribution function w N (T) of quantum jumps in time interval T is found. Computer simulation of quantum jumps is realized. Statistical treatment of simulated jumps reveals sub-Poissonian statistics of quantum jumps. The theoretical distribution function w N (T) fits well the distribution of jumps found from simulated data. Experimental data on quantum jumps found in experiments with single Hg + ion are described by the function w N (T) well

  9. 4-D single particle tracking of synthetic and proteinaceous microspheres reveals preferential movement of nuclear particles along chromatin – poor tracks

    Directory of Open Access Journals (Sweden)

    Athale Chaitanya

    2004-11-01

    Full Text Available Abstract Background The dynamics of nuclear organization, nuclear bodies and RNPs in particular has been the focus of many studies. To understand their function, knowledge of their spatial nuclear position and temporal translocation is essential. Typically, such studies generate a wealth of data that require novel methods in image analysis and computational tools to quantitatively track particle movement on the background of moving cells and shape changing nuclei. Results We developed a novel 4-D image processing platform (TIKAL for the work with laser scanning and wide field microscopes. TIKAL provides a registration software for correcting global movements and local deformations of cells as well as 2-D and 3-D tracking software. With this new tool, we studied the dynamics of two different types of nuclear particles, namely nuclear bodies made from GFP-NLS-vimentin and microinjected 0.1 μm – wide polystyrene beads, by live cell time-lapse microscopy combined with single particle tracking and mobility analysis. We now provide a tool for the automatic 3-D analysis of particle movement in parallel with the acquisition of chromatin density data. Conclusions Kinetic analysis revealed 4 modes of movement: confined obstructed, normal diffusion and directed motion. Particle tracking on the background of stained chromatin revealed that particle movement is directly related to local reorganization of chromatin. Further a direct comparison of particle movement in the nucleoplasm and the cytoplasm exhibited an entirely different kinetic behaviour of vimentin particles in both compartments. The kinetics of nuclear particles were slightly affected by depletion of ATP and significantly disturbed by disruption of actin and microtubule networks. Moreover, the hydration state of the nucleus had a strong impact on the mobility of nuclear bodies since both normal diffusion and directed motion were entirely abolished when cells were challenged with 0.6 M

  10. 4-D single particle tracking of synthetic and proteinaceous microspheres reveals preferential movement of nuclear particles along chromatin – poor tracks

    Science.gov (United States)

    Bacher, Christian P; Reichenzeller, Michaela; Athale, Chaitanya; Herrmann, Harald; Eils, Roland

    2004-01-01

    Background The dynamics of nuclear organization, nuclear bodies and RNPs in particular has been the focus of many studies. To understand their function, knowledge of their spatial nuclear position and temporal translocation is essential. Typically, such studies generate a wealth of data that require novel methods in image analysis and computational tools to quantitatively track particle movement on the background of moving cells and shape changing nuclei. Results We developed a novel 4-D image processing platform (TIKAL) for the work with laser scanning and wide field microscopes. TIKAL provides a registration software for correcting global movements and local deformations of cells as well as 2-D and 3-D tracking software. With this new tool, we studied the dynamics of two different types of nuclear particles, namely nuclear bodies made from GFP-NLS-vimentin and microinjected 0.1 μm – wide polystyrene beads, by live cell time-lapse microscopy combined with single particle tracking and mobility analysis. We now provide a tool for the automatic 3-D analysis of particle movement in parallel with the acquisition of chromatin density data. Conclusions Kinetic analysis revealed 4 modes of movement: confined obstructed, normal diffusion and directed motion. Particle tracking on the background of stained chromatin revealed that particle movement is directly related to local reorganization of chromatin. Further a direct comparison of particle movement in the nucleoplasm and the cytoplasm exhibited an entirely different kinetic behaviour of vimentin particles in both compartments. The kinetics of nuclear particles were slightly affected by depletion of ATP and significantly disturbed by disruption of actin and microtubule networks. Moreover, the hydration state of the nucleus had a strong impact on the mobility of nuclear bodies since both normal diffusion and directed motion were entirely abolished when cells were challenged with 0.6 M sorbitol. This effect correlated

  11. Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

    International Nuclear Information System (INIS)

    Leith, J.L.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Walton, R.E.; Woodruff, K.H.; Howard, J.

    1980-01-01

    The response of rat spinal cord to irradiation with accelerated heavy ions, in particular carbon and neon ions has been studied. Two different ionization regions in the modified Bragg curve for each ion have been studied for both single and fractionated exposures. We have defined the paralytic response as a function of dose and dose per fraction, and we have determined RBE and repair values. The response of rat spinal cord is both dose and LET dependent, which allows the derivation of RBE and repair values

  12. Shot-noise-limited monitoring and phase locking of the motion of a single trapped ion.

    Science.gov (United States)

    Bushev, P; Hétet, G; Slodička, L; Rotter, D; Wilson, M A; Schmidt-Kaler, F; Eschner, J; Blatt, R

    2013-03-29

    We perform a high-resolution real-time readout of the motion of a single trapped and laser-cooled Ba+ ion. By using an interferometric setup, we demonstrate a shot-noise-limited measurement of thermal oscillations with a resolution of 4 times the standard quantum limit. We apply the real-time monitoring for phase control of the ion motion through a feedback loop, suppressing the photon recoil-induced phase diffusion. Because of the spectral narrowing in the phase-locked mode, the coherent ion oscillation is measured with a resolution of about 0.3 times the standard quantum limit.

  13. Preparation and coherent manipulation of pure quantum states of a single molecular ion

    Science.gov (United States)

    Chou, Chin-Wen; Kurz, Christoph; Hume, David B.; Plessow, Philipp N.; Leibrandt, David R.; Leibfried, Dietrich

    2017-05-01

    Laser cooling and trapping of atoms and atomic ions has led to advances including the observation of exotic phases of matter, the development of precision sensors and state-of-the-art atomic clocks. The same level of control in molecules could also lead to important developments such as controlled chemical reactions and sensitive probes of fundamental theories, but the vibrational and rotational degrees of freedom in molecules pose a challenge for controlling their quantum mechanical states. Here we use quantum-logic spectroscopy, which maps quantum information between two ion species, to prepare and non-destructively detect quantum mechanical states in molecular ions. We develop a general technique for optical pumping and preparation of the molecule into a pure initial state. This enables us to observe high-resolution spectra in a single ion (CaH+) and coherent phenomena such as Rabi flopping and Ramsey fringes. The protocol requires a single, far-off-resonant laser that is not specific to the molecule, so many other molecular ions, including polyatomic species, could be treated using the same methods in the same apparatus by changing the molecular source. Combined with the long interrogation times afforded by ion traps, a broad range of molecular ions could be studied with unprecedented control and precision. Our technique thus represents a critical step towards applications such as precision molecular spectroscopy, stringent tests of fundamental physics, quantum computing and precision control of molecular dynamics.

  14. Feasibility of Observing and Characterizing Single Ion Strikes in Microelectronic Components

    International Nuclear Information System (INIS)

    Dingreville, Remi Philippe Michel; Hattar, Khalid Mikhiel; Bufford, Daniel Charles

    2015-01-01

    The transient degradation of semiconductor device performance under irradiation has long been an issue of concern. A single high-energy charged particle can degrade or permanently destroy the microelectronic component, potentially altering the course or function of the systems. Disruption of the the crystalline structure through the introduction of quasi-stable defect structures can change properties from semiconductor to conductor. Typically, the initial defect formation phase is followed by a recovery phase in which defect-defect or defect-dopant interactions modify the characteristics of the damaged structure. In this LDRD Express, in-situ ion irradiation transmission microscopy (TEM) in-situ TEM experiments combined with atomistic simulations have been conducted to determine the feasibility of imaging and characterizing the defect structure resulting from a single cascade in silicon. In-situ TEM experiments have been conducted to demonstrate that a single ion strike can be observed in Si thin films with nanometer resolution in real time using the in-situ ion irradiation transmission electron microscope (I 3 TEM). Parallel to this experimental effort, ion implantation has been numerically simulated using Molecular Dynamics (MD). This numerical framework provides detailed predictions of the damage and follow the evolution of the damage during the first nanoseconds. The experimental results demonstrate that single ion strike can be observed in prototypical semiconductors.

  15. A systematic investigation of differential effects of cell culture substrates on the extent of artifacts in single-molecule tracking.

    Directory of Open Access Journals (Sweden)

    Laura C Zanetti-Domingues

    Full Text Available Single-molecule techniques are being increasingly applied to biomedical investigation, notwithstanding the numerous challenges they pose in terms of signal-to-noise ratio issues. Non-specific binding of probes to glass substrates, in particular, can produce experimental artifacts due to spurious molecules on glass, which can be particularly deleterious in live-cell tracking experiments. In order to resolve the issue of non-specific probe binding to substrates, we performed systematic testing of a range of available surface coatings, using three different proteins, and then extended our assessment to the ability of these coatings to foster cell growth and retain non-adhesive properties. Linear PEG, a passivating agent commonly used both in immobilized-molecule single-molecule techniques and in tissue engineering, is able to both successfully repel non-specific adhesion of fluorescent probes and to foster cell growth when functionalized with appropriate adhesive peptides. Linear PEG treatment results in a significant reduction of tracking artifacts in EGFR tracking with Affibody ligands on a cell line expressing EGFR-eGFP. The findings reported herein could be beneficial to a large number of experimental situations where single-molecule or single-particle precision is required.

  16. Xenon gas field ion source from a single-atom tip

    Science.gov (United States)

    Lai, Wei-Chiao; Lin, Chun-Yueh; Chang, Wei-Tse; Li, Po-Chang; Fu, Tsu-Yi; Chang, Chia-Seng; Tsong, T. T.; Hwang, Ing-Shouh

    2017-06-01

    Focused ion beam (FIB) systems have become powerful diagnostic and modification tools for nanoscience and nanotechnology. Gas field ion sources (GFISs) built from atomic-size emitters offer the highest brightness among all ion sources and thus can improve the spatial resolution of FIB systems. Here we show that the Ir/W(111) single-atom tip (SAT) can emit high-brightness Xe+ ion beams with a high current stability. The ion emission current versus extraction voltage was analyzed from 150 K up to 309 K. The optimal emitter temperature for maximum Xe+ ion emission was ˜150 K and the reduced brightness at the Xe gas pressure of 1 × 10-4 torr is two to three orders of magnitude higher than that of a Ga liquid metal ion source, and four to five orders of magnitude higher than that of a Xe inductively coupled plasma ion source. Most surprisingly, the SAT emitter remained stable even when operated at 309 K. Even though the ion current decreased with increasing temperature, the current at room temperature (RT) could still reach over 1 pA when the gas pressure was higher than 1 × 10-3 torr, indicating the feasibility of RT-Xe-GFIS for application to FIB systems. The operation temperature of Xe-SAT-GFIS is considerably higher than the cryogenic temperature required for the helium ion microscope (HIM), which offers great technical advantages because only simple or no cooling schemes can be adopted. Thus, Xe-GFIS-FIB would be easy to implement and may become a powerful tool for nanoscale milling and secondary ion mass spectroscopy.

  17. A Monte-Carlo code for the detailed simulation of electron and light-ion tracks in condensed matter

    International Nuclear Information System (INIS)

    Emfietzoglou, D.; Papamichael, G.; Karava, K.; Androulidakis, I.; Pathak, A.; Phillips, G. W.; Moscovitch, M.; Kostarelos, K.

    2006-01-01

    In an effort to understand the basic mechanism of the action of charged particles in solid radiation dosimeters, we extend our Monte-Carlo code (MC4) to condensed media (liquids/solids) and present new track-structure calculations for electrons and protons. Modeling the energy dissipation process is based on a model dielectric function, which accounts in a semi-empirical and self-consistent way for condensed-phase effects which are computationally intractable. Importantly, these effects mostly influence track-structure characteristics at the nano-meter scale, which is the focus of radiation action models. Since the event-by-event scheme for electron transport is impractical above several kilo-electron volts, a condensed-history random-walk scheme has been implemented to transport the energetic delta rays produced by energetic ions. Based on the above developments, new track-structure calculations are presented for two representative dosimetric materials, namely, liquid water and silicon. Results include radial dose distributions in cylindrical and spherical geometries, as well as, clustering distributions, which, among other things, are important in predicting irreparable damage in biological systems and prompt electric-fields in microelectronics. (authors)

  18. Improving accuracy of overhanging structures for selective laser melting through reliability characterization of single track formation on thick powder beds

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Hattel, Jesper Henri

    2016-01-01

    Repeatability and reproducibility of parts produced by selective laser melting is a standing issue, and coupled with a lack of standardized quality control presents a major hindrance towards maturing of selective laser melting as an industrial scale process. Consequently, numerical process...... modelling has been adopted towards improving the predictability of the outputs from the selective laser melting process. Establishing the reliability of the process, however, is still a challenge, especially in components having overhanging structures.In this paper, a systematic approach towards...... establishing reliability of overhanging structure production by selective laser melting has been adopted. A calibrated, fast, multiscale thermal model is used to simulate the single track formation on a thick powder bed. Single tracks are manufactured on a thick powder bed using same processing parameters...

  19. A study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    Science.gov (United States)

    Wright, Kenneth Herbert, Jr.

    1988-01-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory.

  20. Study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    International Nuclear Information System (INIS)

    Wright, K.H. Jr.

    1988-02-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory

  1. Electron impact single detachment on the F- ions using the heavy ion storage ring CRYRING: cross-section determination

    International Nuclear Information System (INIS)

    Andersson, K.; Hanstorp, D.; Oesterdahl, F.; Danared, H.; Kaellberg, A.

    2001-01-01

    Electron Impact Single Detachment (EISD) of F - has been studied using the heavy ion storage ring CRYRING at the Manne Siegbahn Laboratory, Stockholm, Sweden. F - ions stored in the ring were merged with an electron beam in one of the ring sections. Neutral F atoms produced in the EISD process were detected in the zero-degree direction using a surface barrier detector. The threshold for the detachment process was found to be around 7.6 eV, thus more than twice the binding energy of F - . The cross-sections increased smoothly up to 55 eV where it reached a maximum of 1.9 x 10 -16 cm 2 . At higher energies a slow decrease of the cross-section was observed, which follows the energy dependence predicted by the Bethe-Born approximation. The experiment showed that CRYRING can be used favourably for studies of anions, and several experiments are forthcoming. (orig.)

  2. Displacement tracking in single human trabecula with metal-plated micro-spheres using X-ray radiography imaging

    International Nuclear Information System (INIS)

    Jiroušek, O; Kytýř, D; Doktor, T; Dammer, J; Krejčí, F

    2013-01-01

    This study presents an improved radiographic method for strain measurement in very small samples of a single trabeculae. X-ray micro-radiography was used to track the deformation behaviour of individual trabecula during mechanical loading. As the X-ray micro-radiography images of a single trabecula show no significant features applicable for digital image correlation (DIC) a random pattern of markers was created on the surfaces of the samples to improve the accuracy of tracking. Metal plated borosilicate glassmicro-spheres (mean diameter 10 μm) were used as the markers for trabecular displacement tracking. Two different X-ray imaging setups were used for this purpose. The specimens of isolated trabeculae were loaded by a micro-mechanical testing device developed with respect to radiographical observation. This compact device enables a high precision three-point bending measurement. The specimen was continuously irradiated during the loading procedure by a micro-focus X-ray source. The radiographs were acquired by a single-photon counting silicon pixel detector and s flat panel sensor with CsI flipped scintillator plate. Circular Hough transform was used to locate positions of the spherical markers in the sequence of acquired radiographs and to calculate the strain in the loaded sample. The gold-coated micro-spheres provide clearly visible features in the sequence of radiographs after beam hardening correction, which in conjunction with pattern recognition algorithm enables to substantially improve the accuracy of strain measurements.

  3. Exploring Transduction Mechanisms of Protein Transduction Domains (PTDs in Living Cells Utilizing Single-Quantum Dot Tracking (SQT Technology

    Directory of Open Access Journals (Sweden)

    Yasuhiro Suzuki

    2012-01-01

    Full Text Available Specific protein domains known as protein transduction domains (PTDs can permeate cell membranes and deliver proteins or bioactive materials into living cells. Various approaches have been applied for improving their transduction efficacy. It is, therefore, crucial to clarify the entry mechanisms and to identify the rate-limiting steps. Because of technical limitations for imaging PTD behavior on cells with conventional fluorescent-dyes, how PTDs enter the cells has been a topic of much debate. Utilizing quantum dots (QDs, we recently tracked the behavior of PTD that was derived from HIV-1 Tat (TatP in living cells at the single-molecule level with 7-nm special precision. In this review article, we initially summarize the controversy on TatP entry mechanisms; thereafter, we will focus on our recent findings on single-TatP-QD tracking (SQT, to identify the major sequential steps of intracellular delivery in living cells and to discuss how SQT can easily provide direct information on TatP entry mechanisms. As a primer for SQT study, we also discuss the latest findings on single particle tracking of various molecules on the plasma membrane. Finally, we discuss the problems of QDs and the challenges for the future in utilizing currently available QD probes for SQT. In conclusion, direct identification of the rate-limiting steps of PTD entry with SQT should dramatically improve the methods for enhancing transduction efficiency.

  4. Visualization of metallodrugs in single cells by secondary ion mass spectrometry imaging.

    Science.gov (United States)

    Wu, Kui; Jia, Feifei; Zheng, Wei; Luo, Qun; Zhao, Yao; Wang, Fuyi

    2017-07-01

    Secondary ion mass spectrometry, including nanoscale secondary ion mass spectrometry (NanoSIMS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), has emerged as a powerful tool for biological imaging, especially for single cell imaging. SIMS imaging can provide information on subcellular distribution of endogenous and exogenous chemicals, including metallodrugs, from membrane through to cytoplasm and nucleus without labeling, and with high spatial resolution and chemical specificity. In this mini-review, we summarize recent progress in the field of SIMS imaging, particularly in the characterization of the subcellular distribution of metallodrugs. We anticipate that the SIMS imaging method will be widely applied to visualize subcellular distributions of drugs and drug candidates in single cells, exerting significant influence on early drug evaluation and metabolism in medicinal and pharmaceutical chemistry. Recent progress of SIMS applications in characterizing the subcellular distributions of metallodrugs was summarized.

  5. Surface structure modification of single crystal graphite after slow, highly charged ion irradiation

    Science.gov (United States)

    Alzaher, I.; Akcöltekin, S.; Ban-d'Etat, B.; Manil, B.; Dey, K. R.; Been, T.; Boduch, P.; Rothard, H.; Schleberger, M.; Lebius, H.

    2018-04-01

    Single crystal graphite was irradiated by slow, highly charged ions. The modification of the surface structure was studied by means of Low-Energy Electron Diffraction. The observed damage cross section increases with the potential energy, i.e. the charge state of the incident ion, at a constant kinetic energy. The potential energy is more efficient for the damage production than the kinetic energy by more than a factor of twenty. Comparison with earlier results hints to a strong link between early electron creation and later target atom rearrangement. With increasing ion fluence, the initially large-scale single crystal is first transformed into μ m-sized crystals, before complete amorphisation takes place.

  6. Towards a precise measurement of atomic parity violation in a single Ra+ ion

    International Nuclear Information System (INIS)

    Nuñez Portela, M.; Berg, J. E. van den; Bekker, H.; Böll, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W.

    2013-01-01

    A single trapped Ra  +  (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z 3 . This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba  +  ions as a precursor for radioactive Ra  +  . Online laser spectroscopy of the isotopes 209 − 214 Ra  +  in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra  +  ion could function as a very stable clock.

  7. Towards a precise measurement of atomic parity violation in a single Ra{sup +} ion

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Portela, M., E-mail: nunez@kvi.nl; Berg, J. E. van den; Bekker, H.; Boell, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W. [Kernfysisch Versneller Instituut (KVI) (Netherlands)

    2013-03-15

    A single trapped Ra{sup + } (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z{sup 3}. This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba{sup + } ions as a precursor for radioactive Ra{sup + }. Online laser spectroscopy of the isotopes {sup 209 - 214}Ra{sup + } in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra{sup + } ion could function as a very stable clock.

  8. Development of noise-suppressed detector for single ion hit system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Takuro; Hamano, Tsuyoshi; Suda, Tamotsu; Hirao, Toshio; Kamiya, Tomihiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    A noise-suppressed detector for single ion detection has been developed, and combined with the heavy ion microbeam apparatus. This detector consists of a pair of micro channel plates (MCP`s) and a very thin carbon foil. The detection signal is formed by the coincidence of the signals from these MCP`s, so that this detector and the coincidence measurement unit can reduce miscounting in the circuit. The detection efficiency for 15 MeV heavy ions was evaluated to be comparable to that of a silicon surface-barrier detector (SSD) and the miscounting rate was 4 orders lower than the noise rate of a single MCP. The rise time of the detection signal was also estimated. (author)

  9. Heavy doping of CdTe single crystals by Cr ion implantation

    Science.gov (United States)

    Popovych, Volodymyr D.; Böttger, Roman; Heller, Rene; Zhou, Shengqiang; Bester, Mariusz; Cieniek, Bogumil; Mroczka, Robert; Lopucki, Rafal; Sagan, Piotr; Kuzma, Marian

    2018-03-01

    Implantation of bulk CdTe single crystals with high fluences of 500 keV Cr+ ions was performed to achieve Cr concentration above the equilibrium solubility limit of this element in CdTe lattice. The structure and composition of the implanted samples were studied using secondary ion mass spectrometry (SIMS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) to characterize the incorporation of chromium into the host lattice and to investigate irradiation-induced damage build-up. It was found that out-diffusion of Cr atoms and sputtering of the targets alter the depth distribution and limit concentration of the projectile ions in the as-implanted samples. Appearance of crystallographically oriented, metallic α-Cr nanoparticles inside CdTe matrix was found after implantation, as well as a strong disorder at the depth far beyond the projected range of the implanted ions.

  10. Broadband Dielectric Spectroscopy and Quasi-Elastic Neutron Scattering on Single-Ion Polymer Conductors

    Science.gov (United States)

    Soles, Christopher; Peng, Hua-Gen; Page, Kirt; Snyder, Chad; Pandy, Ashoutosh; Jeong, Youmi; Runt, James; NIST Collaboration; Pennsylvania Collaboration

    2011-03-01

    The application of solid polymer electrolytes in rechargeable batteries has not been fully realized after decades of research due to its low conductivity. Dramatic increases of the ion conductivity are needed and this progress requires the understanding of conduction mechanism. We address this topic in two fronts, namely, the effect of plasticizer additives and geometric confinement on the charge transfer mechanism. To this end, we combine broadband dielectric spectroscopy (BDS) to characterize the ion mobility and quasi-elastic neutron scattering (QENS) to quantify segmental motion on a single-ion model polymer electrolyte. Deuterated small molecules were used as plasticizers so that the segmental motion of the polymer electrolyte could be monitored by QENS to understand the mechanism behind the increased conductivity. Anodic aluminum oxide (AAO) membranes with well defined channel sizes are used as the matrix to study the transport of ions solvated in a 1D polymer electrolyte.

  11. 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.)

  12. Ion mass dependence for low energy channeling in single-wall nanotubes

    International Nuclear Information System (INIS)

    Zheng Liping; Zhu Zhiyuan; Li Yong; Zhu Dezhang; Xia Huihao

    2008-01-01

    An Monte Carlo (MC) simulation program has been used to study ion mass dependence for the low energy channeling of natural- and pseudo-Ar ions in single-wall nanotubes. The MC simulations show that the channeling critical angle Ψ C obeys the (E) -1/2 and the (M 1 ) -1/2 rules, where E is the incident energy and M 1 is the ion mass. The reason for this may be that the motion of the channeled (or de-channeled) ions should be correlated with both the incident energy E and the incident momentum (2M 1 E) 1/2 , in order to obey the conservation of energy and momentum

  13. Selective capillary diffusion of equimolar H2/D2 gas mixtures through etched ion track membranes prepared from polyethylene terephthalate and polyimide

    International Nuclear Information System (INIS)

    Schmidt, K.; Angert, N.; Trautmann, C.

    1996-01-01

    The selective capillary diffusion of equimolar H 2 /D 2 gas mixtures through ion track membranes prepared from polyethylene terephthalate and polyimide was investigated at a temperature of 293 K, a primary pressure of 0.15 MPa and a secondary pressure of 10 -4 MPa. Different values of the separation factor Z(H 2 /D 2 ) between experiment and computer simulation exists in the case of polyethylene terephthalate ion track membranes because of multiple pores. Membranes for which multiple pores were reduced by varying the irradiation angle showed an increased separation factor. The separation factor is a function of the pore diameter. This is shown for polyimide ion track membranes with a pore size in the range of 0.17 and 0.5 μm. After grafting with styrene the separation factor increased, indicating grafting within the pores. (orig.)

  14. Recording of heavy ion tracks in silicates. Application to the determination of the abundance of ultra-heavy elements in old solar cosmic radiation

    International Nuclear Information System (INIS)

    Duraud, J.-P.

    1978-12-01

    The aim of this thesis is to determine the abundance A(Z) and energy spectrum of the elements of atomic number Z present in cosmic radiation, by means of fossil traces recorded in moon and meteorite minerals. The difficulties due amongst other things to natural annealing are examined in detail in part one, of this paper, the outcome being a thorough study of the processes responsible for the formation, chemical attack and annealing of heavy ion tracks. Part two describes an original approach used here and consisting of a combined analysis as a function of annealing for a given track, of the microscopic structure of the latent track and its attack rate. Part three uses the new rules established beforehand to propose a new method of studying the UH ion (Z>30) to VH ion (20 [fr

  15. Immobilization of pseudorabies virus in porcine tracheal respiratory mucus revealed by single particle tracking.

    Directory of Open Access Journals (Sweden)

    Xiaoyun Yang

    Full Text Available Pseudorabies virus (PRV initially replicates in the porcine upper respiratory tract. It easily invades the mucosae and submucosae for subsequent spread throughout the body via blood vessels and nervous system. In this context, PRV developed ingenious processes to overcome different barriers such as epithelial cells and the basement membrane. Another important but often overlooked barrier is the substantial mucus layer which coats the mucosae. However, little is known about how PRV particles interact with porcine respiratory mucus. We therefore measured the barrier properties of porcine tracheal respiratory mucus, and investigated the mobility of nanoparticles including PRV in this mucus. We developed an in vitro model utilizing single particle tracking microscopy. Firstly, the mucus pore size was evaluated with polyethylene glycol coupled (PEGylated nanoparticles and atomic force microscope. Secondly, the mobility of PRV in porcine tracheal respiratory mucus was examined and compared with that of negative, positive and PEGylated nanoparticles. The pore size of porcine tracheal respiratory mucus ranged from 80 to 1500 nm, with an average diameter of 455±240 nm. PRV (zeta potential: -31.8±1.5 mV experienced a severe obstruction in porcine tracheal respiratory mucus, diffusing 59-fold more slowly than in water. Similarly, the highly negatively (-49.8±0.6 mV and positively (36.7±1.1 mV charged nanoparticles were significantly trapped. In contrast, the nearly neutral, hydrophilic PEGylated nanoparticles (-9.6±0.8 mV diffused rapidly, with the majority of particles moving 50-fold faster than PRV. The mobility of the particles measured was found to be related but not correlated to their surface charge. Furthermore, PEGylated PRV (-13.8±0.9 mV was observed to diffuse 13-fold faster than native PRV. These findings clearly show that the mobility of PRV was significantly hindered in porcine tracheal respiratory mucus, and that the obstruction of PRV

  16. Dimer self-organization of impurity ytterbium ions in synthetic forsterite single crystals

    Science.gov (United States)

    Tarasov, V. F.; Sukhanov, A. A.; Dudnikova, V. B.; Zharikov, E. V.; Lis, D. A.; Subbotin, K. A.

    2017-07-01

    Paramagnetic centers formed by impurity Yb3+ ions in synthetic forsterite (Mg2SiO4) grown by the Czochralski technique are studied by X-band CW and pulsed EPR spectroscopy. These centers are single ions substituting magnesium in two different crystallographic positions denoted M1 and M2, and dimer associates formed by two Yb3+ ions in nearby positions M1. It is established that there is a pronounced mechanism favoring self-organization of ytterbium ions in dimer associates during the crystal growth, and the mechanism of the spin-spin coupling between ytterbium ions in the associate has predominantly a dipole-dipole character, which makes it possible to control the energy of the spin-spin interaction by changing the orientation of the external magnetic field. The structural computer simulation of cluster ytterbium centers in forsterite crystals is carried out by the method of interatomic potentials using the GULP 4.0.1 code (General Utility Lattice Program). It is established that the formation of dimer associates in the form of a chain parallel to the crystallographic axis consisting of two ytterbium ions with a magnesium vacancy between them is the most energetically favorable for ytterbium ions substituting magnesium in the position M1.

  17. Interaction of singly and multiply charged ions with a lithium-fluoride surface

    International Nuclear Information System (INIS)

    Wirtz, L.

    2001-10-01

    Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the attraction due to the self-image potential. In a simulation that treats electronic and nuclear dynamics simultaneously, we show that the image attraction dominates over the repulsive force. Backscattering of very slow multiply charged projectiles high above the surface without touching it ('trampoline effect') does not take place. Instead, the projectile ion penetrates into the surface or is reflected due to close binary collision with surface ions. The case of a singly charged ion in front of an LiF surface is within the reach of ab-initio calculations. We use a multi-configuration self consistent field (MCSCF) and a multi-reference configuration interaction (MR-CI) method to calculate adiabatic potential energy curves for a system consisting of the projectile ion and an embedded cluster of surface ions. With increasing cluster size, the energy levels of the embedded cluster converge towards the band structure of the infinitely extended solid. Due to

  18. Amorphous track predictions in ‘libamtrack’ for alanine relative effectiveness in ion beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Greilich, Steffen; Grzanka, Leszek

    2011-01-01

    and simple dose response, the alanine detector can help to study fundamental assumptions and accuracy in amorphous track modelling. The libamtrack project enabled recently to directly compare various flavours of ATMs. We therefore present here the potential of predictions for alanine from two libamtrack ATMs...... transport and stopping powers hinders a thorough interpretation of the deviation found and stress the necessity for a broader data base at lower particle energies....

  19. Long-Distance Single Photon Transmission from a Trapped Ion via Quantum Frequency Conversion

    Science.gov (United States)

    Walker, Thomas; Miyanishi, Koichiro; Ikuta, Rikizo; Takahashi, Hiroki; Vartabi Kashanian, Samir; Tsujimoto, Yoshiaki; Hayasaka, Kazuhiro; Yamamoto, Takashi; Imoto, Nobuyuki; Keller, Matthias

    2018-05-01

    Trapped atomic ions are ideal single photon emitters with long-lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables the efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single 40Ca+ ion coupled to an optical cavity over a 10 km optical fiber via frequency conversion from 866 nm to the telecom C band at 1530 nm. We observe nonclassical photon statistics of the direct cavity emission, the converted photons, and the 10 km transmitted photons, as well as the preservation of the photons' temporal shape throughout. This telecommunication-ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation.

  20. Hydrophobization of track membrane surface by ion-plasma sputtering method

    Science.gov (United States)

    Kuklin, I. E.; Khlebnikov, N. A.; Barashev, N. R.; Serkov, K. V.; Polyakov, E. V.; Zdorovets, M. V.; Borgekov, D. B.; Zhidkov, I. S.; Cholakh, S. O.; Kozlovskiy, A. L.

    2017-09-01

    This article reviews the possibility of applying inorganic coatings of metal compounds on PTM by ion-plasma sputtering. The main aim of this research is to increase the contact angle of PTM surfaces and to impart the properties of a hydrophobic material to it. After the modification, the initial contact angle increased from 70° to 120°.

  1. Track profile and range studies of heavy and light ions in CR-39: effect of thermal pre-treatment on etching characteristics

    International Nuclear Information System (INIS)

    Al-Najjar, S.A.R.; Bull, R.K.; Durrani, S.A.

    1982-01-01

    Sheets of CR 39 have been irradiated with 20 Ne, 32 S, 40 Ar, 56 Fe and 63 Cu ions at normal incidence to the surface of the sheets and at normal incidence to the edges. The profiles of the etched tracks have been observed side-on and measurements made of the variation of V (the ratio of track to bulk etching velocities) along the tracks and of the fully etched range of the tracks. Heating the plastic at 100 0 C prior to etching produces zones within the plastic having different bulk etching rates Vsub(B). An outer zone of low Vsub(B) is followed by a zone of much higher Vsub(B). This allows tracks to be readily etched to very large diameters, comparable in size to the breakdown spots produced by electrochemical etching. (author)

  2. A comparative study of track registration response of Makrofol-(KG, KL and N) polycarbonate to sup 4 sup 0 Ar ions

    CERN Document Server

    Kumar, A

    1999-01-01

    In the present work a comparative study of track registration response of sup 4 sup 0 Ar ions in different types of Makrofol polycarbonates viz. Makrofol-KG, KL and N have been done. The etched track parameters viz. bulk etch rate, track etch rate, etch rate ratio, cone angle and etching efficiency were calculated. The variation of etching rates with temperature were found to be exponential and follow the Arrhenius equation. The values of activation energy for bulk and track etching were also calculated. Maximum etchable track length/range were also obtained and compared with the theoretical values obtained from computer program RANGE. From the results it is found that the polycarbonates having same chemical composition manufactured by different chemical processes have slightly different behavior

  3. Ionoluminescence analysis of glass scintillators and application to single-ion-hit real-time detection

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Akihito, E-mail: yokoyama.akihito@jaea.go.jp [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Kada, Wataru [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Satoh, Takahiro; Koka, Masashi [Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Shimada, Keisuke; Yokoata, Yuya; Miura, Kenta; Hanaizumi, Osamu [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)

    2016-03-15

    In this paper, we propose and test a real-time detection system for single-ion hits using mega-electronvolt (MeV)-heavy ions. The system was constructed using G2000 and G9 glass scintillators, as well as an electron-multiplying charge-coupled device (EMCCD) camera combined with an inverted microscope with a 10× objective lens. Commercially available G2000 and G9 glass scintillators, which have been reported to exhibit strong photoluminescence at 489, 543, 585, and 622 nm as a result of the Tb{sup 3+} f–f transition, were employed for highly accurate ionized particle detection. The EMCCD camera had a resolution of 512 × 512 pixels, each with a size of 16 μm × 16 μm, and a maximum linear gain of 8 × 10{sup 5} electrons. For 260-MeV Ne, 3 ion hits/s were detected by our system. The intensity of the ionoluminescence (IL) peak induced by the heavy ions was 140 times the noise intensity. In contrast, the luminous diameter at the full width at half maximum (FWHM) in both the horizontal and vertical directions was calculated to be approximately 4.5 μm. These results suggest that our detection system can accurately detect single-ion hits with a diameter of the order of 1 μm.

  4. Comparison of DMSP cross-track ion drifts and SuperDARN line-of-sight velocities

    Directory of Open Access Journals (Sweden)

    R. A. Drayton

    2005-10-01

    Full Text Available Cross-track ion drifts measured by the DMSP satellites are compared with line-of-sight SuperDARN HF velocities in approximately the same directions. Good overall agreement is found for a data set comprising of 209 satellite passes over the field of view of nine SuperDARN radars in both the Northern and Southern Hemispheres. The slope of the best linear fit line relating the SuperDARN and DMSP velocities is of the order of 0.7 with a tendency for SuperDARN velocities to be smaller. The agreement implies that the satellite and radar data can be merged into a common set provided that spatial and temporal variations of the velocity as measured by both instruments are smooth.

    Keywords. Ionosphere (Ionospheric irregularities; Plasma convection; Auroral ionosphere

  5. A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

    Science.gov (United States)

    García, F.; Grahn, T.; Hoffmann, J.; Jokinen, A.; Kaya, C.; Kunkel, J.; Rinta-Antila, S.; Risch, H.; Rusanov, I.; Schmidt, C. J.; Simon, H.; Simons, C.; Turpeinen, R.; Voss, B.; Äystö, J.; Winkler, M.

    2018-03-01

    The GEM-TPC described herein will be part of the standard beam-diagnostics equipment of the Super-FRS. This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z = 1 up to Z = 92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs on the middle plane with respect to the second one. In order to put this development in context, the evolution of previous prototypes will be described and its performances discussed. Finally, this chamber was tested at the University of Jyväskylä accelerator with proton projectiles and at GSI with Uranium, Xenon, fragments and Carbon beams. The results obtained have shown a position resolution between 120 to 300 μm at moderate counting rate under conditions of full tracking efficiency.

  6. Single and Multiple Object Tracking Using a Multi-Feature Joint Sparse Representation.

    Science.gov (United States)

    Hu, Weiming; Li, Wei; Zhang, Xiaoqin; Maybank, Stephen

    2015-04-01

    In this paper, we propose a tracking algorithm based on a multi-feature joint sparse representation. The templates for the sparse representation can include pixel values, textures, and edges. In the multi-feature joint optimization, noise or occlusion is dealt with using a set of trivial templates. A sparse weight constraint is introduced to dynamically select the relevant templates from the full set of templates. A variance ratio measure is adopted to adaptively adjust the weights of different features. The multi-feature template set is updated adaptively. We further propose an algorithm for tracking multi-objects with occlusion handling based on the multi-feature joint sparse reconstruction. The observation model based on sparse reconstruction automatically focuses on the visible parts of an occluded object by using the information in the trivial templates. The multi-object tracking is simplified into a joint Bayesian inference. The experimental results show the superiority of our algorithm over several state-of-the-art tracking algorithms.

  7. Influence of copper single crystal structures on the reflection of low energy hydrogen and helium ions

    International Nuclear Information System (INIS)

    Feijen, H.H.W.

    1975-01-01

    A theoretical basis for the 'wedge-focussing' phenomenon is outlined. Investigations have been made to check up to what extent proton reflection can be simulated by using H 2 + or H 3 + as incident ions and analysing the reflected protons. The results of an experimental study of the influence of surface semi-channels on the reflection of low energy ( + , H 2 + and He + ions from copper single crystals with attention to the wedge-focussing effect are presented (G.T.H.)

  8. Ion Feedback Suppression Using Inclined MCP Holes in a Single-MCP+Micromegas+Pads Detector

    International Nuclear Information System (INIS)

    Va'vra, J.; Sumiyoshi, T.

    2005-01-01

    We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in a presence of magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (Microchannel) plate, a Micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

  9. Single electron attachment and stripping cross sections for relativistic heavy ions

    International Nuclear Information System (INIS)

    Crawford, H.J.

    1979-06-01

    The results of a Bevalac experiment to measure the single electron attachment and stripping cross sections for relativistic (0.5 1 , and fully stripped, N 0 , ion beams emerging from the targets. Separate counters measured the number of ions in each charge state. The ratios N 1 /N 0 for different target thicknesses were fit to a simple growth curve to yield electron attachment and stripping cross sections. The data are compared to relativistic extrapolations of available theories. Clear evidence for two separate attachment processes, radiative and non-radiative, is found. Data are compared to a recently improved formulation for the stripping cross sections

  10. Modification of mechanical properties of single crystal aluminum oxide by ion beam induced structural changes

    International Nuclear Information System (INIS)

    Ensinger, W.; Nowak, R.; Horino, Y.; Baba, K.

    1993-01-01

    The mechanical behaviour of ceramics is essentially determined by their surface qualities. As a surface modification technique, ion implantation provides the possibility to modify the mechanical properties of ceramics. Highly energetic ions are implanted into the near-surface region of a material and modify its composition and structure. Ions of aluminum, oxygen, nickel and tantalum were implanted into single-crystal α-aluminum oxide. Three-point bending tests showed that an increase in flexural strength of up to 30% could be obtained after implantation of aluminum and oxygen. Nickel and tantalum ion implantation increased the fracture toughness. Indentation tests with Knoop and Vickers diamonds and comparison of the lengths of the developed radial cracks showed that ion implantation leads to a reaction in cracking. The observed effects are assigned to radiation induced structural changes of the ceramic. Ion bombardment leads to radiation damage and formation of compressive stress. In case of tantalum implantation, the implanted near-surface zone becomes amorphous. These effects make the ceramic more resistant to fracture. (orig.)

  11. Engineering of electronic properties of single layer graphene by swift heavy ion irradiation

    Science.gov (United States)

    Kumar, Sunil; Kumar, Ashish; Tripathi, Ambuj; Tyagi, Chetna; Avasthi, D. K.

    2018-04-01

    In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.

  12. A modified fast-track program for pancreatic surgery: a prospective single-center experience.

    Science.gov (United States)

    di Sebastiano, Pierluigi; Festa, Leonardina; De Bonis, Antonio; Ciuffreda, Andrea; Valvano, Maria Rosa; Andriulli, Angelo; di Mola, F Francesco

    2011-03-01

    The objective of this study is to evaluate the impact of a fast-track protocol in a high-volume center for patients with pancreatic disorders. The concept of fast-track surgery allowing accelerated postoperative recovery is accepted in colorectal surgery, but efficacy data are only preliminary for patients undergoing major pancreatic surgery. We aimed to evaluate the impact of a modified fast-track protocol in a high-volume center for patients with pancreatic disorders. Between February 2005 and January 2010, 145 subjects had resective pancreatic surgery and were enrolled in the program. Essential features of the program were no preanaesthetic medication, upper and lower air-warming device, avoidance of excessive i.v. fluids perioperatively, effective control of pain, early reinstitution of oral feeding, and immediate mobilization and restoration of bowel function following surgery. Outcome measures were postoperative complications such as pancreatic fistula, delayed gastric emptying, biliary leak, intra-abdominal abscess, post-pancreatectomy hemorrhage, acute pancreatitis, wound infection, 30-day mortality, postoperative hospital stay, and readmission rates. On average, patients were discharged on postoperative day 10 (range 6-69), with a 30-day readmission rate of 6.2%. Percentage of patients with at least one complication was 38.6%. Pancreatic anastomotic leakage occurred in seven of 101 pancreatico-jejunostomies, and biliary leak in three of 109 biliary jejunostomies. Postoperative hemorrhage occurred in ten (6.9%) patients and wound infection in nine (6.2%) cases. In-hospital mortality was 2.7%. Fast-track parameters, such as normal food and first stool, correlated significantly with early discharge (jaundice, and resumption of normal diet by the 5th postoperative day were independent factors of early discharge. Fast-track programs are feasible, easy, and also applicable for patients undergoing a major surgery such as pancreatic resection.

  13. The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

    Science.gov (United States)

    Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

    2017-10-01

    Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

  14. Ionization and single electron capture in collision of highly charged Ar16+ ions with helium

    International Nuclear Information System (INIS)

    Wang Fei; Gou Bingcong

    2008-01-01

    This paper uses the two-centre atomic orbital close-coupling method to study the ionization and the single electron capture in collision of highly charged Ar 16+ ions with He atoms in the velocity range of 1.2–1.9 a.u. The relative importance of single ionization (SI) to single capture (SC) is explored. The comparison between the calculation and experimental data shows that the SI/SC cross section ratios from this work are in good agreement with experimental data. The total single electron ionization cross sections and the total single electron capture cross sections are also given for this collision. The investigation of the partial electron capture cross section shows a general tendency of capture to larger n and l with increasing velocity from 1.2 to 1.9 a.u

  15. Synthesizing single-phase β-FeSi2 via ion beam irradiations of Fe/Si bilayers

    International Nuclear Information System (INIS)

    Milosavljevic, M.; Dhar, S.; Schaaf, P.; Bibic, N.; Lieb, K.P.

    2001-01-01

    This paper presents results on the direct synthesis of the β-FeSi 2 phase by ion beam mixing of Fe/Si bilayers with Xe ions. The influence of the substrate temperature, ion fluence and energy on the growth of this phase was investigated using Rutherford backscattering (RBS), X-ray diffraction (XRD) and conversion electron Moessbauer spectroscopy (CEMS). Complete growth of single-phase β-FeSi 2 was achieved by 205 keV Xe ion irradiation to a fluence of 2x10 16 ions/cm 2 at 600 deg. C. We propose a two-step reaction mechanism involving thermal and ion beam energy deposition

  16. Etched ion tracks in silicon oxide and silicon oxynitride as charge injection or extraction channels for novel electronic structures

    International Nuclear Information System (INIS)

    Fink, D.; Petrov, A.V.; Hoppe, K.; Fahrner, W.R.; Papaleo, R.M.; Berdinsky, A.S.; Chandra, A.; Chemseddine, A.; Zrineh, A.; Biswas, A.; Faupel, F.; Chadderton, L.T.

    2004-01-01

    The impact of swift heavy ions onto silicon oxide and silicon oxynitride on silicon creates etchable tracks in these insulators. After their etching and filling-up with highly resistive matter, these nanometric pores can be used as charge extraction or injection paths towards the conducting channel in the underlying silicon. In this way, a novel family of electronic structures has been realized. The basic characteristics of these 'TEMPOS' (=tunable electronic material with pores in oxide on silicon) structures are summarized. Their functionality is determined by the type of insulator, the etch track diameters and lengths, their areal densities, the type of conducting matter embedded therein, and of course by the underlying semiconductor and the contact geometry. Depending on the TEMPOS preparation recipe and working point, the structures may resemble gatable resistors, condensors, diodes, transistors, photocells, or sensors, and they are therefore rather universally applicable in electronics. TEMPOS structures are often sensitive to temperature, light, humidity and organic gases. Also light-emitting TEMPOS structures have been produced. About 37 TEMPOS-based circuits such as thermosensors, photosensors, humidity and alcohol sensors, amplifiers, frequency multipliers, amplitude modulators, oscillators, flip-flops and many others have already been designed and successfully tested. Sometimes TEMPOS-based circuits are more compact than conventional electronics

  17. Measuring the radial density distribution of light emission around the track of fast ions in nitrogen

    International Nuclear Information System (INIS)

    Ibach, T.

    1983-01-01

    For analysing the emission and stopping of ionization electrons (σ-electrons) emitted by fast ions passing through a gas, the radial density distribution of the light emission of the (0,0) transition of two optical bands in nitrogen have been measured. The systems selected for the epxeriments are the 2nd positive system (2.PS) at 337.1 nm primarily excited by low-energy electrons of about 20 eV, and the first negative system (1.NS) at 391.4 nm excited by faster electrons and simultaneous ionization. The equipment developed for the experiments records the light emission with a telescope-type optical arrangement including interference filters, allowing high local resolution and dynamics of the measured range. The measurements have been carried out at pressures between 0.133 and 13.3 mbar, using photons of energies ranging from 270 keV to 2.8 MeV, helium 3 beams of 270 keV/u and 500 keV/u, and neon beams of 270 keV/u. Abel's inversion applied to the distance functions allows calculation of the spatial light emission density which is normalized for a gas density of 1 g/cm 3 . The profiles of the two bands indicate that the σ-electron spectrum gets harder in outward direction. Next to the beam the impact density decreases faster with increasing ion energy than the stopping power (increasing interaction range of the σ-electrons). With photon beams, about half of the whole light emission in the 1. NS, and of the ionization, is induced by primary interactions of the ion beam. This proportion decreases at constant energy per nucleon with increasing atomic number of the ions as compared with the σ-electrons. The primary σ-emission gets harder with higher atomic numbers. (orig./HP) [de

  18. Femto-clock for the electron kinetics in swift heavy ion tracks

    Czech Academy of Sciences Publication Activity Database

    Medvedev, Nikita; Volkov, A.E.

    2017-01-01

    Roč. 50, č. 44 (2017), s. 1-11, č. článku 445302. ISSN 0022-3727 R&D Projects: GA MŠk LG15013; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 Keywords : swift heavy ions * electron kinetics * femto-clock * femtosecond resolution * spectroscopy * radiative decay Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016

  19. Dynamic optimization approach for integrated supplier selection and tracking control of single product inventory system with product discount

    Science.gov (United States)

    Sutrisno; Widowati; Heru Tjahjana, R.

    2017-01-01

    In this paper, we propose a mathematical model in the form of dynamic/multi-stage optimization to solve an integrated supplier selection problem and tracking control problem of single product inventory system with product discount. The product discount will be stated as a piece-wise linear function. We use dynamic programming to solve this proposed optimization to determine the optimal supplier and the optimal product volume that will be purchased from the optimal supplier for each time period so that the inventory level tracks a reference trajectory given by decision maker with minimal total cost. We give a numerical experiment to evaluate the proposed model. From the result, the optimal supplier was determined for each time period and the inventory level follows the given reference well.

  20. Extending the applicability of an open-ring trap to perform experiments with a single laser-cooled ion

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo, J. M.; Colombano, M.; Doménech, J.; Rodríguez, D., E-mail: danielrodriguez@ugr.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada (Spain); Block, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, 55099 Mainz (Germany); Institut für Kernchemie, University of Mainz, 55099 Mainz (Germany); Delahaye, P. [Grand Accélérateur National d’Ions Lourds, 14000 Caen (France)

    2015-10-15

    A special ion trap was initially built up to perform β-ν correlation experiments with radioactive ions. The trap geometry is also well suited to perform experiments with laser-cooled ions, serving for the development of a new type of Penning trap, in the framework of the project TRAPSENSOR at the University of Granada. The goal of this project is to use a single {sup 40}Ca{sup +} ion as detector for single-ion mass spectrometry. Within this project and without any modification to the initial electrode configuration, it was possible to perform Doppler cooling on {sup 40}Ca{sup +} ions, starting from large clouds and reaching single ion sensitivity. This new feature of the trap might be important also for other experiments with ions produced at radioactive ion beam facilities. In this publication, the trap and the laser system will be described, together with their performance with respect to laser cooling applied to large ion clouds down to a single ion.

  1. The case for a single-axis tracking solar PV array system to mitigate against the time-of-use tariff

    CSIR Research Space (South Africa)

    Szewczuk, S

    2016-08-01

    Full Text Available peak tariff is from 6:00pm to 8:00pm. A fixed-axis PV system generates peak electricity when the sun is overhead of the PV array. A single-axis PV tracking system allows for maximum production of electricity by tracking the sun soon after it appears...

  2. Damage evolution in Xe-ion irradiated rutile (TiO2) single crystals

    International Nuclear Information System (INIS)

    Li, F.; Sickafus, K.E.; Evans, C.R.; Nastasi, M.

    1999-01-01

    Rutile (TiO 2 ) single crystals with (110) orientation were irradiated with 360 keV Xe 2+ ions at 300 K to fluences ranging from 2 x 10 19 to 1 x 10 20 Xe/m 2 . Irradiated samples were analyzed using: (1) Rutherford backscattering spectroscopy combined with ion channeling analysis (RBS/C); and (2) cross-sectional transmission electron microscopy (XTEM). Upon irradiation to a fluence of 2 x 10 19 Xe/m 2 , the sample thickness penetrated by the implanted ions was observed to consist of three distinct layers: (1) a defect-free layer at the surface (thickness about 12 nm) exhibiting good crystallinity; (2) a second layer with a low density of relatively large-sized defects; and (3) a third layer consisting of a high concentration of small defects. After the fluence was increased to 7 x 10 19 Xe/m 2 , a buried amorphous layer was visible by XTEM. The thickness of the amorphous layer was found to increase with increasing Xe ion fluence. The location of this buried amorphous layer was found to coincide with the measured peak in the Xe concentration (measured by RBS/C), rather than with the theoretical maximum in the displacement damage profile. This observation suggests the implanted Xe ions may serve as nucleation sites for the amorphization transformation. The total thickness of the damaged microstructure due to ion irradiation was always found to be much greater than the projected range of the Xe ions. This is likely due to point defect migration under the high stresses induced by ion implantation

  3. Multiple single-unit long-term tracking on organotypic hippocampal slices using high-density microelectrode arrays

    Directory of Open Access Journals (Sweden)

    Wei Gong

    2016-11-01

    Full Text Available A novel system to cultivate and record from organotypic brain slices directly on high-density microelectrode arrays (HD-MEA was developed. This system allows for continuous recording of electrical activity of specific individual neurons at high spatial resolution while monitoring at the same time, neuronal network activity. For the first time, the electrical activity patterns of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied during several consecutive weeks at daily intervals. An unsupervised iterative spike-sorting algorithm, based on PCA and k-means clustering, was developed to assign the activities to the single units. Spike-triggered average extracellular waveforms of an action potential recorded across neighboring electrodes, termed ‘footprints’ of single-units were generated and tracked over weeks. The developed system offers the potential to study chronic impacts of drugs or genetic modifications on individual neurons in slice preparations over extended times.

  4. Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

    International Nuclear Information System (INIS)

    Szabó, J.; Pálfalvi, J.K.

    2012-01-01

    The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008–2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

  5. Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, J., E-mail: julianna.szabo@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary); Palfalvi, J.K. [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary)

    2012-12-01

    The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008-2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

  6. Single-column ion chromatography with determination of hydrazoic acid produced in spent nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Ma Guilan; Tan Shuping

    2006-01-01

    The reaction of hydrazine and its derivative with ammonium metavanadate may produce hydrazoic acid (HN 3 ). A single-column ion chromatography is used for the determination of HN 3 after neutralizing the rest acid in the sample with sodium hydroxide. Chromatography separation of HN 3 is carried out on a 25 cm x 0.46 cm (inside diameter) stainless steel column packed with Vydac IC302 ion Chromatography packing. The eluent is 1 mmol/L o-phthalic acid, and the ion is detected by conductivity detector. The detection limit in the presence chromatography is 5 μg/mL, the linear range is from 5 to 201 μg/mL, the linear correlation coefficient is 0.9994, respectively. The analysis accuracy is 2% for standard sample, and the detection limit is 51 μg/mL for HN 3 in the real sample. (authors)

  7. Single capture and transfer ionization in collisions of Clq+ projectile ions incident on helium

    International Nuclear Information System (INIS)

    Wong, K.L.; Ben-Itzhak, I.; Cocke, C.L.; Giese, J.P.; Richard, P.

    1995-01-01

    The Kansas State University linac has been used to measure the ratio of the cross sections for the processes of transfer ionization (TI) and single capture (SC) for 2 MeV/amu Cl q+ where q=7, 9, 13, 14, and 15 projectile ions incident on a helium target. The ratio was determined using a helium gas jet target by measuring coincidences between projectile-ion and recoil-ion final charge states. The σ TI /σ SC for Cl q+ were compared to measurements of bare F 9+ and hydrogenlike F 8+ and O 7+ taken at the same velocity. The ratios deviate from a q 2 scaling which is predicted in the perturbative regime. This deviation is attributed to screening by the projectile electrons for low q=7 and 9, and to the collision being non-perturbative for high q. A possible saturation effect in the ratio was observed for q similar 14. (orig.)

  8. The scattering of low energy helium ions and atoms from a copper single crystal, ch. 2

    International Nuclear Information System (INIS)

    Verheij, L.K.; Poelsema, B.; Boers, A.L.

    1976-01-01

    The scattering of 4-10 keV helium ions from a copper surface cannot be completely described with elastic, single collisions. The general behaviour of the measured energy and width of the surface peak can be explained by differences in inelastic energy losses for scattering from an ideal surface and from surface structures (damage). Multiple scattering effects have a minor influence. Additional information about the inelastic processes is obtained from scattering experiments with a primary atom beam. For large angles of incidence, the energy of the reflected ions is reduced about 20 eV if the primary beam consists of atoms instead of ions. An explanation of this effect and an explanation of the different behaviour of small angles is given. In the investigated energy range, the electronic stopping power might depend on the charge state of the primary particles. The experimental results are rather well explained by the Lindhard, Scharff, Schioett theory

  9. Tracking single cells in live animals using a photoconvertible near-infrared cell membrane label.

    Science.gov (United States)

    Carlson, Alicia L; Fujisaki, Joji; Wu, Juwell; Runnels, Judith M; Turcotte, Raphaël; Spencer, Joel A; Celso, Cristina Lo; Scadden, David T; Strom, Terry B; Lin, Charles P

    2013-01-01

    We describe a novel photoconversion technique to track individual cells in vivo using a commercial lipophilic membrane dye, DiR. We show that DiR exhibits a permanent fluorescence emission shift (photoconversion) after light exposure and does not reacquire the original color over time. Ratiometric imaging can be used to distinguish photoconverted from non-converted cells with high sensitivity. Combining the use of this photoconvertible dye with intravital microscopy, we tracked the division of individual hematopoietic stem/progenitor cells within the calvarium bone marrow of live mice. We also studied the peripheral differentiation of individual T cells by tracking the gain or loss of FoxP3-GFP expression, a marker of the immune suppressive function of CD4(+) T cells. With the near-infrared photoconvertible membrane dye, the entire visible spectral range is available for simultaneous use with other fluorescent proteins to monitor gene expression or to trace cell lineage commitment in vivo with high spatial and temporal resolution.

  10. EXPERIMENTAL TARGET INJECTION AND TRACKING SYSTEM CONSTRUCTION AND SINGLE SHOT TESTING

    International Nuclear Information System (INIS)

    PETZOLDT, R.W.; ALEXANDER, N.B.; DRAKE, T.J.; GOODIN, D.T; JONESTRACK, K; VERMILLION, B.A

    2003-01-01

    Targets must be injected into an IFE power plant at a rate of approximately 5 to 10 Hz. Targets must be tracked very accurately to allow driver beams to be aligned with defined points on the targets with accuracy ± 150 (micro)m for indirect drive and ± 20 (micro)m for direct drive. An experimental target injection and tracking system has been constructed at General Atomics. The injector system will be used as a tool for testing the survivability of various target designs and provide feedback to the target designers. Helium gas propels the targets down an 8 m gun barrel up to 400 m/s. Direct-drive targets are protected in the barrel by sabots that are spring loaded to separate into two halves after acceleration. A sabot deflector directs the sabot halves away from the target injection path. Targets will be optically tracked with laser beams and line-scan cameras. Target position and arrival time will be predicted in real time based on early target position measurements. The system installation will be described. System testing to overcome excessive projectile wear and debris in the gun barrel is presented

  11. Coupled chemical reactions in dynamic nanometric confinement: IV. Ion transmission spectrometric analysis of nanofluidic behavior and membrane formation during track etching in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Munoz, G. H.; Arellano, H. G.; Kiv, A.; Alfonta, L.

    2015-01-01

    Roč. 170, č. 3 (2015), s. 155-174 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : ions * etching * tracks Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.472, year: 2015

  12. Coupled chemical reactions in dynamic nanometric confinement: V. The influence of Li+ and F- ions on etching of nuclear tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Hernandez, G. M.; Ruiz, N. L.; Vacík, Jiří; Hnatowicz, Vladimír; Garcia-Arellano, H.; Alfonta, L.; Kiv, A.

    2014-01-01

    Roč. 169, č. 5 (2014), s. 396-417 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : tracks * biotechnology * nanostruct * ions * etching Subject RIV: BO - Biophysics Impact factor: 0.513, year: 2014

  13. Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

    International Nuclear Information System (INIS)

    Leith, J.T.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Howard, J.

    1982-01-01

    The thoraco-lumbar (T12-L1) region of the spinal cord of rats was exposed to either single or fractionated (four daily exposures) doses of X rays (230 kVp) or heavy ions. The heavy ions used were carbon and neon, and the relative biological effectiveness (RBE) of both the plateau ionization region and the midpeak region of 4-cm spread-out Bragg peaks of each heavy ion were investigated. For single doses of carbon and neon ions in the plateau ionization region, RBE values of 1.45 +/- 0.25 (propagated 95% confidence limits) and 1.46 +/- 0.33, respectively, were obtained. In the spread peak regions for carbon and neon ions, the RBE values were 1.48 +/- 0.18 and 1.86 +/- 0.42, respectively. These values were obtained using the dose needed to produce 50% paralysis in a group of irradiated rats as the isoeffect comparison dose (ED 50 dose). Similarly, in groups of rats receiving four daily exposures, the RBE values for carbon and neon ions in the plateau ionization region were 1.31 +/- 0.27 and 1.80 +/- 0.24, respectively. In the spread peak regions of ionization for carbon and neon ions, the RBE values were 1.95 +/- 0.19 and 2.18 +/- 0.23, respectively. Similar values for RBE were obtained using changes in the activity of enzymes in spinal cord tissue (cyclic nucleotide phosphohydrolase and γ-glutamyl transpeptidase). Also, it was estimated that, for X irradiation, the fractional amount of dose repaired (at the ED 50 dose) was 0.64 +/- 0.10 (95% confidence limits). For carbon and neon ions in the plateau ionization region, the values for the fractional amount of dose repaired were 0.70 +/- 0.27 and 0.48 +/- 0.20, and for carbon and neon ions in the spread peak region of ionization, the fractional repair values were 0.40 +/- 0.10 and 0.52 +/- 0.17. Spinal cord tissue therefore shows a high capacity for subeffective damage repair

  14. The single-ion anisotropy effects in the mixed-spin ternary-alloy

    Science.gov (United States)

    Albayrak, Erhan

    2018-04-01

    The effect of single-ion anisotropy on the thermal properties of the ternary-alloy in the form of ABpC1-p is investigated on the Bethe lattice (BL) in terms of exact recursion relations. The simulation on the BL consists of placing A atoms (spin-1/2) on the odd shells and randomly placing B (spin-3/2) or C (spin-5/2) atoms with concentrations p and 1 - p, respectively, on the even shells. The phase diagrams are calculated in possible planes spanned by the system parameters: temperature, single-ion anisotropy, concentration and ratio of the bilinear interaction parameters for z = 3 corresponding to the honeycomb lattice. It is found that the crystal field drives the system to the lowest possible state therefore reducing the temperatures of the critical lines in agreement with the literature.

  15. Focused ion beam patterning to dielectrophoretically assemble single nanowire based devices

    International Nuclear Information System (INIS)

    La Ferrara, V; Massera, E; Francia, G Di; Alfano, B

    2010-01-01

    Direct-write processing is increasingly taking place in nanodevice fabrication. In this work, Focused Ion Beam (FIB), a powerful tool in maskless micromachining, is used for electrode patterning onto a silicon/silicon nitride substrate. Then a single palladium nanowire is assembled between electrodes by means of dielectrophoresis (DEP). The nanowire morphology depends on the electrode pattern when DEP conditions are fixed. FIB/DEP combination overcomes the problem of nanowire electrical contamination due to gallium ion bombardment and the as-grown nanowire retains its basic electrical properties. Single nanowire based devices have been fabricated with this novel approach and have been tested as hydrogen sensors, confirming the reliability of this technology.

  16. Tracking metal ions with polypyrrole thin films adhesively bonded to diazonium-modified flexible ITO electrodes.

    Science.gov (United States)

    Lo, Momath; Diaw, Abdou K D; Gningue-Sall, Diariatou; Aaron, Jean-Jacques; Oturan, Mehmet A; Chehimi, Mohamed M

    2018-05-09

    Adhesively bonded polypyrrole thin films doped with benzene sulfonic acid (BSA) were electrodeposited on aminobenzenediazonium-modified flexible ITO electrodes and further employed for the detection of Pb 2+ , Cu 2+ , and Cd 2+ metal ions in aqueous medium. The aminophenyl (AP) adhesive layer was grafted to ITO by electroreduction of the in situ generated parent diazonium compound. Polypyrrole (PPy) thin films exhibited remarkable adhesion to aminophenyl (ITO-AP). The strongly adherent polypyrrole films exhibited excellent electroactivity in the doped state with BSA which itself served to chelate the metal ions in aqueous medium. The surface of the resulting, modified flexible electrode was characterized by XPS, SEM, and electrochemical methods. The ITO-AP-PPy electrodes were then used for the simultaneous detection of Cu 2+ , Cd 2+ , and Pb 2+ by differential pulse voltammetry (DPV). The detection limits were 11.1, 8.95, and 0.99 nM for Cu 2+ , Cd 2+ , and Pb 2+ , respectively. In addition, the modified electrodes displayed a good reproducibility, making them suitable for the determination of heavy metals in real wastewater samples.

  17. A generalized Jaynes-Cummings model: The relativistic parametric amplifier and a single trapped ion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-Guillén, D., E-mail: dojedag@ipn.mx [Escuela Superior de Cómputo, Instituto Politécnico Nacional, Av. Juan de Dios Bátiz esq. Av. Miguel Othón de Mendizábal, Col. Lindavista, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico); Mota, R. D. [Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana No. 1000, Col. San Francisco Culhuacán, Delegación Coyoacán, C.P. 04430 Ciudad de México (Mexico); Granados, V. D. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ed. 9, Unidad Profesional Adolfo López Mateos, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico)

    2016-06-15

    We introduce a generalization of the Jaynes-Cummings model and study some of its properties. We obtain the energy spectrum and eigenfunctions of this model by using the tilting transformation and the squeezed number states of the one-dimensional harmonic oscillator. As physical applications, we connect this new model to two important and novelty problems: the relativistic parametric amplifier and the quantum simulation of a single trapped ion.

  18. Single and double electron capture in collisions of highly ionized, decelerated Ge ions with Ne

    International Nuclear Information System (INIS)

    Stoehlker, T.; Kozhuharov, C.; Mokler, P.H.; Olson, R.E.; Stachura, Z.; Warczak, A.

    1992-03-01

    Experimental cross-sections for non-radiative single and double electron capture from Ne target into H-like Ge ions at low intermediate collision energies (4-12) MeV/u are presented. The results are compared with theoretical calculations and an empirical scaling rule. Information concerning the impact parameter dependence of electron capture is extracted using classical trajectory Monte Carlo calculations. (orig.)

  19. Formation of etchable tracks in plastics

    International Nuclear Information System (INIS)

    Katz, R.

    1984-01-01

    It is proposed that etchable tracks in plastics are formed by the interaction of delta-rays with polymer clusters, paralleling the formation of developable tracks in emulsion. We speak of a latent image, a grain count regime, and a track-width regime for the tracks of single particles. We may speak of 'ion-kill' and 'gamma-kill', as in radiobiology, when dealing with irradiation by a beam of particles. Existing but incomplete experimental evidence is consistent with these concepts. Such evidence as there is suggests that CR-39 is a 1-or more hit detector. (author)

  20. Anisotropy effect of crater formation on single crystal silicon surface under intense pulsed ion beam irradiation

    Science.gov (United States)

    Shen, Jie; Yu, Xiao; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Liang, Guoying; Yu, Xiang; Huang, Wanying; Shahid, Ijaz; Zhang, Xiaofu; Yan, Sha; Le, Xiaoyun

    2018-04-01

    Due to the induced extremely fast thermal and dynamic process, Intense Pulsed Ion Beam (IPIB) is widely applied in material processing, which can bring enhanced material performance and surface craters as well. To investigate the craters' formation mechanism, a specific model was built with Finite Element Methods (FEM) to simulate the thermal field on irradiated single crystal silicon. The direct evidence for the existence of the simulated 6-fold rotational symmetric thermal distribution was provided by electron microscope images obtained on single crystal silicon. The correlation of the experiment and simulation is of great importance to understand the interaction between IPIB and materials.

  1. Heisenberg magnetic chain with single-ion easy-plane anisotropy: Hubbard operators approach

    International Nuclear Information System (INIS)

    Spirin, D.V.; Fridman, Y.A.

    2003-01-01

    We investigate the gap in excitation spectrum of one-dimensional S=1 ferro- and antiferromagnets with easy-plane single-ion anisotropy. The self-consistent modification of Hubbard operators approach which enables to account single-site term exactly is used. For antiferromagnetic model we found Haldane phase that exists up to point D=4J (where D is anisotropy parameter, J is exchange coupling), while quadrupolar phase realizes at larger values of anisotropy. Our results specify those of Golinelli et al. (Phys. Rev. B. 45 (1992) 9798), where similar model was studied. Besides the method gives gap value closer to numerical estimations than usual spin-wave theories

  2. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

  3. Experimental study on heavy-ion single event effect on nanometer DDR SRAM

    International Nuclear Information System (INIS)

    Luo Yinhong; Zhang Fengqi; Guo Hongxia; Zhou Hui; Wang Yanping; Zhang Keying

    2013-01-01

    Single event effect experimental study on 90 nm and 65 nm DDR SRAM were carried out, single event upset (SEU) cross section was discussed as a function of several parameters such as feature size, test pattern, incidence angle, supply voltage. Key influence factors and effect rule were analyzed. Feasibility of the current test method was discussed. Results indicate that, SEU cross section reduces as technologies scale down; the influence of test pattern and power supply on SEU cross section is small; tilt angle increases SEU cross section due to multiple upset increasement. The applicability of cosine tilt test method is correlative to ion species and linear energy transfer (LET) values. (authors)

  4. Investigating change of properties in gallium ion irradiation patterned single-layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Dong, Jinyao; Bai, Bing [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Xie, Guoxin [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2016-10-14

    Besides its excellent physical properties, graphene promises to play a significant role in electronics with superior properties, which requires patterning of graphene for device integration. Here, we presented the changes in properties of single-layer graphene before and after patterning using gallium ion beam. Combined with Raman spectra of graphene, the scanning capacitance microscopy (SCM) image confirmed that a metal–insulator transition occurred after large doses of gallium ion irradiation. The changes in work function and Raman spectra of graphene indicated that the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. The patterning width of graphene presented an increasing trend due to the scattering influence of the impurities and the substrate. - Highlights: • The scanning capacitance microscopy image confirmed a metal–insulator transition occurred after large doses of gallium ion irradiation. • The changes indicated the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. • The patterning width of graphene presented a increasing trend due to the scattering influence of the impurities and the substrate.

  5. Single-crate stand-alone CAMAC control system for a negative ion source test facility

    International Nuclear Information System (INIS)

    Juras, R.C.; Ziegler, N.F.

    1979-01-01

    A single-crate CAMAC system was configured to control a negative ion source development facility at ORNL and control software was written for the crate microcomputer. The software uses inputs from a touch panel and a shaft encoder to control the various operating parameters of the test facility and uses the touch panel to display the operating status. Communication to and from the equipment at ion source potential is accomplished over optical fibers from an ORNL-built CAMAC module. A receiver at ion source potential stores the transmitted data and some of these stored values are then used to control discrete parameters of the ion source (i.e., power supply on or off). Other stored values are sent to a multiplexed digital-to-analog converter to provide analog control signals. A transmitter at ion source potential transmits discrete status information and several channels of analog data from an analog-to-digital converter back to the ground-potential receiver where it is stored to be read and displayed by the software

  6. Impact of temperature on single event upset measurement by heavy ions in SRAM devices

    International Nuclear Information System (INIS)

    Liu Tianqi; Geng Chao; Zhang Zhangang; Gu Song; Tong Teng; Xi Kai; Hou Mingdong; Liu Jie; Zhao Fazhan; Liu Gang; Han Zhengsheng

    2014-01-01

    The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12 C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209 Bi and 12 C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12 C ions but keep constant for 209 Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

  7. Quantum phase transitions in spin-1 X X Z chains with rhombic single-ion anisotropy

    Science.gov (United States)

    Ren, Jie; Wang, Yimin; You, Wen-Long

    2018-04-01

    We explore numerically the inverse participation ratios in the ground state of one-dimensional spin-1 X X Z chains with the rhombic single-ion anisotropy. By employing the techniques of density-matrix renormalization group, effects of the rhombic single-ion anisotropy on various information theoretical measures are investigated, such as the fidelity susceptibility, the quantum coherence, and the entanglement entropy. Their relations with the quantum phase transitions are also analyzed. The phase transitions from the Y -Néel phase to the large-Ex or the Haldane phase can be well characterized by the fidelity susceptibility. The second-order derivative of the ground-state energy indicates all the transitions are of second order. We also find that the quantum coherence, the entanglement entropy, the Schmidt gap, and the inverse participation ratios can be used to detect the critical points of quantum phase transitions. Results drawn from these quantum information observables agree well with each other. Finally we provide a ground-state phase diagram as functions of the exchange anisotropy Δ and the rhombic single-ion anisotropy E .

  8. Towards radiocarbon dating of single foraminifera with a gas ion source

    Science.gov (United States)

    Wacker, L.; Lippold, J.; Molnár, M.; Schulz, H.

    2013-01-01

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 μg for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO2 is liberated from 150 to 1150 μg of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO2 is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 μg (50 μg C) typically gives a 12C- ion source current of 10-15 μA over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 μg Cibicides pseudoungerianus test at 14,030 ± 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  9. Towards radiocarbon dating of single foraminifera with a gas ion source

    International Nuclear Information System (INIS)

    Wacker, L.; Lippold, J.; Molnár, M.; Schulz, H.

    2013-01-01

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 μg for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO 2 is liberated from 150 to 1150 μg of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO 2 is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 μg (50 μg C) typically gives a 12 C − ion source current of 10–15 μA over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 μg Cibicides pseudoungerianus test at 14,030 ± 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  10. Towards radiocarbon dating of single foraminifera with a gas ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, L., E-mail: wacker@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Lippold, J. [Heidelberg Academy of Sciences, 69120 Heidelberg (Germany); Molnar, M. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Schulz, H. [Institute for Geosciencies, University of Tuebingen, 72076 Tuebingen (Germany)

    2013-01-15

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 {mu}g for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO{sub 2} is liberated from 150 to 1150 {mu}g of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO{sub 2} is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 {mu}g (50 {mu}g C) typically gives a {sup 12}C{sup -} ion source current of 10-15 {mu}A over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 {mu}g Cibicides pseudoungerianus test at 14,030 {+-} 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  11. Raman spectroscopy and single-photon source in an ion-cavity system

    International Nuclear Information System (INIS)

    Goncalves de Barros, H.

    2010-01-01

    The work presented in this thesis explores the interaction between a single trapped 40Ca+ ion and the electromagnetic field inside a high-finesse optical cavity. The coupling takes place via the use of a vacuum stimulated Raman transition, which transfers atomic population from the S1/2 to the D3/2 manifolds of the calcium ion producing a photon in the cavity. This photon is measured and properties of the system are evaluated. Spectroscopy measurements of the Raman transitions are performed and all possible transitions are identified for different polarizations of both drive laser and cavity fields. The system is also used to deterministically produce single photons. Simulation curves quantitatively match the experimental results within calibration error bars. The single-photon creation efficiency obtained in this work overcomes previous ion-cavity setups and is comparable to state-of-the-art systems composed of a neutral atom and a cavity operating in the strong coupling regime. (author)

  12. Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics.

    Science.gov (United States)

    Burke, Russell T; Orth, James D

    2016-05-14

    The response of single cells to anti-cancer drugs contributes significantly in determining the population response, and therefore is a major contributing factor in the overall outcome. Immunoblotting, flow cytometry and fixed cell experiments are often used to study how cells respond to anti-cancer drugs. These methods are important, but they have several shortcomings. Variability in drug responses between cancer and normal cells, and between cells of different cancer origin, and transient and rare responses are difficult to understand using population averaging assays and without being able to directly track and analyze them longitudinally. The microscope is particularly well suited to image live cells. Advancements in technology enable us to routinely image cells at a resolution that enables not only cell tracking, but also the observation of a variety of cellular responses. We describe an approach in detail that allows for the continuous time-lapse imaging of cells during the drug response for essentially as long as desired, typically up to 96 hr. Using variations of the approach, cells can be monitored for weeks. With the employment of genetically encoded fluorescent biosensors numerous processes, pathways and responses can be followed. We show examples that include tracking and quantification of cell growth and cell cycle progression, chromosome dynamics, DNA damage, and cell death. We also discuss variations of the technique and its flexibility, and highlight some common pitfalls.

  13. A Direct Maximum Power Point Tracking Method for Single-Phase Grid Connected PV Inverters

    DEFF Research Database (Denmark)

    EL Aamri, Faicel; Maker, Hattab; Sera, Dezso

    2018-01-01

    in dynamic conditions, especially in low irradiance when the measurement of signals becomes more sensitive to noise. The proposed MPPT is designed for single-phase single-stage grid-connected PV inverters, and is based on estimating the instantaneous PV power and voltage ripples, using second...

  14. Last ion engine thrust puts ESA's SMART-1 on the right track for its Moon encounter

    Science.gov (United States)

    2004-10-01

    SMART-1, on its way to the Moon, has now covered more than 80 million kilometres. Its journey started on 27 September 2003, when the spacecraft was launched on board an Ariane 5 rocket from Europe’s spaceport in Kourou, French Guiana. Since then, it has been spiralling in progressively larger orbits around Earth, to eventually be captured by the lunar gravity and enter into orbit around the Moon in November this year. The SMART-1 mission was designed to pursue two main objectives. The first is purely technological: to demonstrate and test a number of space techniques to be applied to future interplanetary exploration missions. The second goal is scientific, mainly dedicated to lunar science. It is the technology demonstration goal, in particular the first European flight test of a solar-powered ion engine as a spacecraft’s main propulsion system, that gave shape to the peculiar route and duration (13 months) of the SMART-1 journey to the Moon. The long spiralling orbit around Earth, which is bringing the spacecraft closer and closer to the Moon, is needed for the ion engine to function and be tested over a distance comparable to that a spacecraft would travel during a possible interplanetary trip. The SMART-1 mission is also testing the response of a spacecraft propelled by such an engine during gravity-assisted manoeuvres. These are techniques currently used on interplanetary journeys, which make use of the gravitational pull of celestial objects (e.g. planets) for the spacecraft to gain acceleration and reach its final target while saving fuel. In SMART-1’s case, the Moon’s gravitational pull has been exploited in three “lunar resonance” manoeuvres. The first two successfully took place in August and September 2004. The last resonance manoeuvre was on 12 October, during the last major ion engine thrust, which lasted nearly five days, from 10 to 14 October. Thanks to this final thrust, SMART-1 will make two more orbits around Earth without any further

  15. Development and applications of single particle orientation and rotational tracking in dynamic systems

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kuangcai [Iowa State Univ., Ames, IA (United States)

    2016-02-19

    The goal of this study is to help with future data analysis and experiment designs in rotational dynamics research using DIC-based SPORT technique. Most of the current studies using DIC-based SPORT techniques are technical demonstrations. Understanding the mechanisms behind the observed rotational behaviors of the imaging probes should be the focus of the future SPORT studies. More efforts are still needed in the development of new imaging probes, particle tracking methods, instrumentations, and advanced data analysis methods to further extend the potential of DIC-based SPORT technique.

  16. The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

    International Nuclear Information System (INIS)

    Wei, Pei; Wei, Zhengying; Chen, Zhen; Du, Jun; He, Yuyang; Li, Junfeng; Zhou, Yatong

    2017-01-01

    Highlights: • The thermal behavior of AlSi10Mg molten pool was analyzed. • The SLM-processed sample with a relatively low surface roughness was obtained. • Effects of parameters on surface topography of scan track were investigated. • Effects of parameters on microstructure of parts were investigated. • Optimum processing parameters for AlSi10Mg SLM was obtained. - Abstract: This densification behavior and attendant microstructural characteristics of the selective laser melting (SLM) processed AlSi10Mg alloy affected by the processing parameters were systematically investigated. The samples with a single track were produced by SLM to study the influences of laser power and scanning speed on the surface morphologies of scan tracks. Additionally, the bulk samples were produced to investigate the influence of the laser power, scanning speed, and hatch spacing on the densification level and the resultant microstructure. The experimental results showed that the level of porosity of the SLM-processed samples was significantly governed by energy density of laser beam and the hatch spacing. The tensile properties of SLM-processed samples and the attendant fracture surface can be enhanced by decreasing the level of porosity. The microstructure of SLM-processed samples consists of supersaturated Al-rich cellular structure along with eutectic Al/Si situated at the cellular boundaries. The Si content in the cellular boundaries increases with increasing the laser power and decreasing the scanning speed. The hardness of SLM-processed samples was significantly improved by this fine microstructure compared with the cast samples. Moreover, the hardness of SLM-processed samples at overlaps was lower than the hardness observed at track cores.

  17. The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Pei; Wei, Zhengying, E-mail: zywei@mail.xjtu.edu.cn; Chen, Zhen; Du, Jun; He, Yuyang; Li, Junfeng; Zhou, Yatong

    2017-06-30

    Highlights: • The thermal behavior of AlSi10Mg molten pool was analyzed. • The SLM-processed sample with a relatively low surface roughness was obtained. • Effects of parameters on surface topography of scan track were investigated. • Effects of parameters on microstructure of parts were investigated. • Optimum processing parameters for AlSi10Mg SLM was obtained. - Abstract: This densification behavior and attendant microstructural characteristics of the selective laser melting (SLM) processed AlSi10Mg alloy affected by the processing parameters were systematically investigated. The samples with a single track were produced by SLM to study the influences of laser power and scanning speed on the surface morphologies of scan tracks. Additionally, the bulk samples were produced to investigate the influence of the laser power, scanning speed, and hatch spacing on the densification level and the resultant microstructure. The experimental results showed that the level of porosity of the SLM-processed samples was significantly governed by energy density of laser beam and the hatch spacing. The tensile properties of SLM-processed samples and the attendant fracture surface can be enhanced by decreasing the level of porosity. The microstructure of SLM-processed samples consists of supersaturated Al-rich cellular structure along with eutectic Al/Si situated at the cellular boundaries. The Si content in the cellular boundaries increases with increasing the laser power and decreasing the scanning speed. The hardness of SLM-processed samples was significantly improved by this fine microstructure compared with the cast samples. Moreover, the hardness of SLM-processed samples at overlaps was lower than the hardness observed at track cores.

  18. Dissecting the insect metabolic machinery using twin ion mass spectrometry: a single P450 enzyme metabolizing the insecticide imidacloprid in vivo.

    Science.gov (United States)

    Hoi, Kin Kuan; Daborn, Phillip J; Battlay, Paul; Robin, Charles; Batterham, Philip; O'Hair, Richard A J; Donald, William A

    2014-04-01

    Insecticide resistance is one of the most prevalent examples of anthropogenic genetic change, yet our understanding of metabolic-based resistance remains limited by the analytical challenges associated with rapidly tracking the in vivo metabolites of insecticides at nonlethal doses. Here, using twin ion mass spectrometry analysis of the extracts of whole Drosophila larvae and excreta, we show that (i) eight metabolites of the neonicotinoid insecticide, imidacloprid, can be detected when formed by susceptible larval genotypes and (ii) the specific overtranscription of a single gene product, Cyp6g1, associated with the metabolic resistance to neonicotinoids, results in a significant increase in the formation of three imidacloprid metabolites that are formed in C-H bond activation reactions; that is, Cyp6g1 is directly linked to the enhanced metabolism of imidacloprid in vivo. These results establish a rapid and sensitive method for dissecting the metabolic machinery of insects by directly linking single gene products to insecticide metabolism.

  19. NIR-emitting molecular-based nanoparticles as new two-photon absorbing nanotools for single particle tracking

    Science.gov (United States)

    Daniel, J.; Godin, A. G.; Clermont, G.; Lounis, B.; Cognet, L.; Blanchard-Desce, M.

    2015-07-01

    In order to provide a green alternative to QDs for bioimaging purposes and aiming at designing bright nanoparticles combining both large one- and two-photon brightness, a bottom-up route based on the molecular engineering of dedicated red to NIR emitting dyes that spontaneously form fluorescent organic nanoparticles (FONs) has been implemented. These fully organic nanoparticles built from original quadrupolar dyes are prepared using a simple, expeditious and green protocol that yield very small molecular-based nanoparticles (radius ~ 7 nm) suspension in water showing a nice NIR emission (λem=710 nm). These FONs typically have absorption coefficient more than two orders larger than popular NIR-emitting dyes (such as Alexa Fluor 700, Cy5.5 ….) and much larger Stokes shift values (i.e. up to over 5500 cm-1). They also show very large two-photon absorption response in the 800-1050 nm region (up to about 106 GM) of major promise for two-photon excited fluorescence microscopy. Thanks to their brightness and enhanced photostability, these FONs could be imaged as isolated nanoparticles and tracked using wide-field imaging. As such, thanks to their size and composition (absence of heavy metals), they represent highly promising alternatives to NIR-emitting QDs for use in bioimaging and single particle tracking applications. Moreover, efficient FONs coating was achieved by using a polymeric additive built from a long hydrophobic (PPO) and a short hydrophilic (PEO) segment and having a cationic head group able to interact with the highly negative surface of FONs. This electrostatically-driven interaction promotes both photoluminescence and two-photon absorption enhancement leading to an increase of two-photon brightness of about one order of magnitude. This opens the way to wide-field single particle tracking under two-photon excitation

  20. An automated approach for single-cell tracking in epifluorescence microscopy applied to E. coli growth analysis on microfluidics biochips

    Science.gov (United States)

    Fetita, Catalin; Kirov, Boris; Jaramillo, Alfonso; Lefevre, Christophe

    2012-03-01

    With the accumulation of knowledge for the intimate molecular mechanisms governing the processes inside the living cells in the later years, the ability to characterize the performance of elementary genetic circuits and parts at the single-cell level is becoming of crucial importance. Biological science is arriving to the point where it can develop hypothesis for the action of each molecule participating in the biochemical reactions and need proper techniques to test those hypothesis. Microfluidics is emerging as the technology that combined with high-magnification microscopy will allow for the long-term single-cell level observation of bacterial physiology. In this study we design, build and characterize the gene dynamics of genetic circuits as one of the basic parts governing programmed cell behavior. We use E. coli as model organism and grow it in microfluidics chips, which we observe with epifluorescence microscopy. One of the most invaluable segments of this technology is the consequent image processing, since it allows for the automated analysis of vast amount of single-cell observation and the fast and easy derivation of conclusions based on that data. Specifically, we are interested in promoter activity as function of time. We expect it to be oscillatory and for that we use GFP (green fluorescent protein) as a reporter in our genetic circuits. In this paper, an automated framework for single-cell tracking in phase-contrast microscopy is developed, combining 2D segmentation of cell time frames and graph-based reconstruction of their spatiotemporal evolution with fast tracking of the associated fluorescence signal. The results obtained on the investigated biological database are presented and discussed.

  1. Label-free tracking of single extracellular vesicles in a nano-fluidic optical fiber (Conference Presentation)

    Science.gov (United States)

    van der Pol, Edwin; Weidlich, Stefan; Lahini, Yoav; Coumans, Frank A. W.; Sturk, Auguste; Nieuwland, Rienk; Schmidt, Markus A.; Faez, Sanli; van Leeuwen, Ton G.

    2016-03-01

    Background: Extracellular vesicles, such as exosomes, are abundantly present in human body fluids. Since the size, concentration and composition of these vesicles change during disease, vesicles have promising clinical applications, including cancer diagnosis. However, since ~70% of the vesicles have a diameter <70 nm, detection of single vesicles remains challenging. Thus far, vesicles <70 nm have only be studied by techniques that require the vesicles to be adhered to a surface. Consequently, the majority of vesicles have never been studied in their physiological environment. We present a novel label-free optical technique to track single vesicles <70 nm in suspension. Method: Urinary vesicles were contained within a single-mode light-guiding silica fiber containing a 600 nm nano-fluidic channel. Light from a diode laser (660 nm wavelength) was coupled to the fiber, resulting in a strongly confined optical mode in the nano-fluidic channel, which continuously illuminated the freely diffusing vesicles inside the channel. The elastic light scattering from the vesicles, in the direction orthogonal to the fiber axis, was collected using a microscope objective (NA=0.95) and imaged with a home-built microscope. Results: We have tracked single urinary vesicles as small as 35 nm by elastic light scattering. Please note that vesicles are low-refractive index (n<1.4) particles, which we confirmed by combining data on thermal diffusion and light scattering cross section. Conclusions: For the first time, we have studied vesicles <70 nm freely diffusing in suspension. The ease-of-use and performance of this technique support its potential for vesicle-based clinical applications.

  2. Single-virus tracking approach to reveal the interaction of Dengue virus with autophagy during the early stage of infection

    Science.gov (United States)

    Chu, Li-Wei; Huang, Yi-Lung; Lee, Jin-Hui; Huang, Long-Ying; Chen, Wei-Jun; Lin, Ya-Hsuan; Chen, Jyun-Yu; Xiang, Rui; Lee, Chau-Hwang; Ping, Yueh-Hsin

    2014-01-01

    Dengue virus (DENV) is one of the major infectious pathogens worldwide. DENV infection is a highly dynamic process. Currently, no antiviral drug is available for treating DENV-induced diseases since little is known regarding how the virus interacts with host cells during infection. Advanced molecular imaging technologies are powerful tools to understand the dynamics of intracellular interactions and molecular trafficking. This study exploited a single-virus particle tracking technology to address whether DENV interacts with autophagy machinery during the early stage of infection. Using confocal microscopy and three-dimensional image analysis, we showed that DENV triggered the formation of green fluorescence protein-fused microtubule-associated protein 1A/1B-light chain 3 (GFP-LC3) puncta, and DENV-induced autophagosomes engulfed DENV particles within 15-min postinfection. Moreover, single-virus particle tracking revealed that both DENV particles and autophagosomes traveled together during the viral infection. Finally, in the presence of autophagy suppressor 3-methyladenine, the replication of DENV was inhibited and the location of DENV particles spread in cytoplasma. In contrast, the numbers of newly synthesized DENV were elevated and the co-localization of DENV particles and autophagosomes was detected while the cells were treated with autophagy inducer rapamycin. Taken together, we propose that DENV particles interact with autophagosomes at the early stage of viral infection, which promotes the replication of DENV.

  3. A comparison of single particle tracking and temporal image correlation spectroscopy for quantitative analysis of endosome motility

    DEFF Research Database (Denmark)

    Lund, F. W.; Wustner, D.

    2013-01-01

    Single particle tracking (SPT) is becoming a standard method to extract transport parameters from time-lapse image sequences of fluorescent vesicles in living cells. Another method to obtain these data is temporal image correlation spectroscopy (TICS), but this method is less often used for measu......Single particle tracking (SPT) is becoming a standard method to extract transport parameters from time-lapse image sequences of fluorescent vesicles in living cells. Another method to obtain these data is temporal image correlation spectroscopy (TICS), but this method is less often used...... for measurement of intracellular vesicle transport. Here, we present an extensive comparison of SPT and TICS. First we examine the effect of photobleaching, shading and noise on SPT and TICS analysis using simulated image sequences. To this end, we developed a simple photophysical model, which relates spatially...... varying illumination intensity to the bleaching propensity and fluorescence intensity of the moving particles. We found that neither SPT nor TICS are affected by photobleaching per se, but the transport parameters obtained by both methods are sensitive to the signal-to-noise ratio. In addition, the number...

  4. Science and technology with nuclear tracks in solids

    CERN Document Server

    Buford-Price, P

    2005-01-01

    Fission track dating has greatly expanded its usefulness to geology over the last 40 years. It is central to thermochronology—the use of shortened fission tracks to decipher the thermal history, movement, and provenance of rocks. When combined with other indicators, such as zircon color and (U–Th)/He, a range of temperatures from C to C can be studied. Combining fission track analysis with cosmogenic nuclide decay rates, one can study landscape development and denudation of passive margins. Technological applications have expanded from biological filters, radon mapping, and dosimetry to the use of ion track microtechnology in microlithography, micromachining by ion track etching, microscopic field emission tips, magnetic nanowires as magnetoresistive sensors, microfluidic devices, physiology of ion channels in single cells, and so on. In nuclear and particle physics, relatively insensitive glass detectors have been almost single-handedly responsible for our knowledge of cluster radioactivity, and plastic ...

  5. Infrared laser dissociation of single megadalton polymer ions in a gated electrostatic ion trap: the added value of statistical analysis of individual events.

    Science.gov (United States)

    Halim, Mohammad A; Clavier, Christian; Dagany, Xavier; Kerleroux, Michel; Dugourd, Philippe; Dunbar, Robert C; Antoine, Rodolphe

    2018-05-07

    In this study, we report the unimolecular dissociation mechanism of megadalton SO 3 -containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) polymer cations and anions with the aid of infrared multiphoton dissociation coupled to charge detection ion trap mass spectrometry. A gated electrostatic ion trap ("Benner trap") is used to store and detect single gaseous polymer ions generated by positive and negative polarity in an electrospray ionization source. The trapped ions are then fragmented due to the sequential absorption of multiple infrared photons produced from a continuous-wave CO 2 laser. Several fragmentation pathways having distinct signatures are observed. Highly charged parent ions characteristically adopt a distinctive "stair-case" pattern (assigned to the "fission" process) whereas low charge species take on a "funnel like" shape (assigned to the "evaporation" process). Also, the log-log plot of the dissociation rate constants as a function of laser intensity between PAMPS positive and negative ions is significantly different.

  6. Single-photon sensitive fast ebCMOS camera system for multiple-target tracking of single fluorophores: application to nano-biophotonics

    Science.gov (United States)

    Cajgfinger, Thomas; Chabanat, Eric; Dominjon, Agnes; Doan, Quang T.; Guerin, Cyrille; Houles, Julien; Barbier, Remi

    2011-03-01

    Nano-biophotonics applications will benefit from new fluorescent microscopy methods based essentially on super-resolution techniques (beyond the diffraction limit) on large biological structures (membranes) with fast frame rate (1000 Hz). This trend tends to push the photon detectors to the single-photon counting regime and the camera acquisition system to real time dynamic multiple-target tracing. The LUSIPHER prototype presented in this paper aims to give a different approach than those of Electron Multiplied CCD (EMCCD) technology and try to answer to the stringent demands of the new nano-biophotonics imaging techniques. The electron bombarded CMOS (ebCMOS) device has the potential to respond to this challenge, thanks to the linear gain of the accelerating high voltage of the photo-cathode, to the possible ultra fast frame rate of CMOS sensors and to the single-photon sensitivity. We produced a camera system based on a 640 kPixels ebCMOS with its acquisition system. The proof of concept for single-photon based tracking for multiple single-emitters is the main result of this paper.

  7. Ion induced scintillation in organic solids: development of an average track model,degradation of the scintillation intensity and dosimetric applications

    International Nuclear Information System (INIS)

    Broggio, D.

    2004-12-01

    This work deals with a specific aspect of the ion-matter interaction: the scintillation induced by ions in organic materials. In the first chapter we tackle the issue in a theoretical way by proposing a method to compute the radial doses within the framework of the mean track model. We have developed a model based on the Lewis transport equation and on the Spencer distribution of the loss energy in order to take into account the transport of secondary electrons in a more realistic way. In the second chapter we study the physical mechanisms that trigger ion-induced scintillation. Ion-induced scintillation is featured by the dependence in charge number of the intensity of scintillation for ions with same energy loss and by the saturation of the scintillation efficiency for ions with high stopping-power. We have applied our model of radial doses to ion-induced scintillation. In the third chapter we study the gradual degradation of the scintillation intensity and ion-induced chemical damages. In the last chapter we propose a prototype of dosimeters based on the combination of scintillators and optical fibers that allows the real-time measurement of the dose delivered by a carbon ion beam in therapeutical use conditions. This dosimeter gives the relationship between the dose and the scintillation intensity but its accuracy is not yet sufficient for uses in radiotherapy. (A.C.)

  8. Track detection on the cells exposed to high Linear Energy Transfer heavy-ions by Cr-39 plastic and terminal deoxynucleotidyl transferase(Td T)

    International Nuclear Information System (INIS)

    Mehnati, P.; Keshtkar, A.; Mesbahi, A.; Sasaki, H.

    2006-01-01

    The fatal effect of ionizing radiation on cells depends on Linear Energy Transfer level. The distribution of ionizing radiation is sparse and homogeneous for low Linear Energy Transfer radiations such as X or y, but it is dense and concentrated for high Linear Energy Transfer radiation such as heavy-ions radiation. Materials and Methods: Chinese hamster ovary cells (CHO-K1) were exposed to 4 Gy Fe-ion 2000 keV/μm. The Cr-39 is a special and sensitive plastic used to verify exact position of heavy-ions traversal. Terminal deoxynucleotidyl transferase is an enzyme labeled with [3 H ] d ATP for detection of cellular DNA damage by autoradiography assay. Results: The track of heavy ions traversals presented by pit size was almost similar for all different doses of radiation. No pits to show the track of traversal were found in 20% of the cell nuclei of the irradiation. Apparently these fractions of cells wave not hit by heavy ions. Conclusion: This study indicated the possible usefulness of both the Cr-39 plastics and DNA labeling with Terminal deoxynucleotidyl transferase method for evaluating the biological effect of heavy-ions in comparison with low Linear Energy Transfer ionizing radiation

  9. Electronic properties of single Ge/Si quantum dot grown by ion beam sputtering deposition.

    Science.gov (United States)

    Wang, C; Ke, S Y; Yang, J; Hu, W D; Qiu, F; Wang, R F; Yang, Y

    2015-03-13

    The dependence of the electronic properties of a single Ge/Si quantum dot (QD) grown by the ion-beam sputtering deposition technique on growth temperature and QD diameter is investigated by conductive atomic force microscopy (CAFM). The Si-Ge intermixing effect is demonstrated to be important for the current distribution of single QDs. The current staircase induced by the Coulomb blockade effect is observed at higher growth temperatures (>700 °C) due to the formation of an additional barrier between dislocated QDs and Si substrate for the resonant tunneling of holes. According to the proposed single-hole-tunneling model, the fact that the intermixing effect is observed to increase as the incoherent QD size decreases may explain the increase in the starting voltage of the current staircase and the decrease in the current step width.

  10. Experimental study of single-electron loss by Ar+ ions in rare-gas atoms

    Science.gov (United States)

    Reyes, P. G.; Castillo, F.; Martínez, H.

    2001-04-01

    Absolute differential and total cross sections for single-electron loss were measured for Ar+ ions on rare-gas atoms in the laboratory energy range of 1.5 to 5.0 keV. The electron loss cross sections for all the targets studied are found to be in the order of magnitude between 10-19 and 10-22 cm2, and show a monotonically increasing behaviour as a function of the incident energy. The behaviour of the total single-electron loss cross sections with the atomic target number, Zt, shows different dependences as the collision energy increases. In all cases the present results display experimental evidence of saturation in the single-electron loss cross section as the atomic number of the target increases.

  11. Design and optimization of a self-developing single axis tracking PV array

    International Nuclear Information System (INIS)

    Colozza, A.J.

    1992-01-01

    This paper reports on a study performed in order to design a tracking PV array and optimize the design for maximum specific power. The design considerations were minimal deployment time, high reliability and small stowage volume. The array design was self-deployable, from a compact stowage configuration, using a passive pressurized gas deployment mechanism. The array structural components consist of a combination of beams, columns and cables used to deploy and orient a flexible PV blanket. Each structural component of the design was analyzed to determine the size necessary to withstand the various forces it would be subjected to. An optimization was performed to determine the array dimensions and blanket geometry which produce the maximum specific power

  12. Scattering of atomic and molecular ions from single crystal surfaces of Cu, Ag and Fe

    International Nuclear Information System (INIS)

    Zoest, J.M. van.

    1986-01-01

    This thesis deals with analysis of crystal surfaces of Cu, Ag and Fe with Low Energy Ion scattering Spectroscopy (LEIS). Different atomic and molecular ions with fixed energies below 7 keV are scattered by a metal single crystal (with adsorbates). The energy and direction of the scattered particles are analysed for different selected charge states. In that way information can be obtained concerning the composition and atomic and electronic structure of the single crystal surface. Energy spectra contain information on the composition of the surface, while structural atomic information is obtained by direction measurements (photograms). In Ch.1 a description is given of the experimental equipment, in Ch.2 a characterization of the LEIS method. Ch.3 deals with the neutralization of keV-ions in surface scattering. Two different ways of data interpretation are presented. First a model is treated in which the observed directional dependence of neutralization action of the first atom layer of the surface is presented by a laterally varying thickness of the neutralizing layer. Secondly it is shown that the data can be reproduced by a more realistic, physical model based on atomic transition matrix elements. In Ch.4 the low energy hydrogen scattering is described. The study of the dissociation of H 2 + at an Ag surface r0230ted in a model based on electronic dissociation, initialized by electron capture into a repulsive (molecular) state. In Ch.5 finally the method is applied to the investigation of the surface structure of oxidized Fe. (Auth.)

  13. Experimental determination of electron shock excitation cross sections for a singly charged gadolinium ion

    International Nuclear Information System (INIS)

    Smirnov, Yu.M.

    1995-01-01

    The trends observed in the processes of excitation with simultaneous ionization have received little study. This is particularly so for rare-earth elements having electron shells of complex structure and optical spectra very rich in lines. Among the basic factors responsible for such a situation, we should mention two: the difficulty presented by theoretical analysis of the processes discussed and the absence of factual information about the excitation cross sections with simultaneous ionization for the majority of rare-earth elements. The aim of the present work is to investigate the excitation of a singly charged gadolinium ion in the collisions of monokinetic electrons with gadolinium atoms. Up to the present time, only the excitation cross sections of a gadolinium atom have been measured, where investigation of the electron shock excitation of gadolinium atoms in their free state is associated with overcoming large experimental difficulties. About 160 crosss sections for the excitation of a singly charged gadolinium ion were measured and for a third of the cross sections; the energy dependences were recorded for the change in energy of the elecrons from the excitation threshold up to 200 eV. Included are tables of the wavelength, transistion, internal quantum number, the energy of the lowere and upper levels, and the values of cross sections for the charged gadolinium ion. Diagrams of the transistion energy states of Gd (II) and spectroscopy are presented and explained

  14. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Hun

    1996-02-15

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10{sup -7} m {center_dot} rad and 7.87 x 10{sup -9}A {center_dot} V{sup -3/2}, respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics.

  15. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    International Nuclear Information System (INIS)

    Kim, Su Hun

    1996-02-01

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10 -7 m · rad and 7.87 x 10 -9 A · V -3/2 , respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics

  16. Ion track based tunable device as humidity sensor: a neural network approach

    Science.gov (United States)

    Sharma, Mamta; Sharma, Anuradha; Bhattacherjee, Vandana

    2013-01-01

    Artificial Neural Network (ANN) has been applied in statistical model development, adaptive control system, pattern recognition in data mining, and decision making under uncertainty. The nonlinear dependence of any sensor output on the input physical variable has been the motivation for many researchers to attempt unconventional modeling techniques such as neural networks and other machine learning approaches. Artificial neural network (ANN) is a computational tool inspired by the network of neurons in biological nervous system. It is a network consisting of arrays of artificial neurons linked together with different weights of connection. The states of the neurons as well as the weights of connections among them evolve according to certain learning rules.. In the present work we focus on the category of sensors which respond to electrical property changes such as impedance or capacitance. Recently, sensor materials have been embedded in etched tracks due to their nanometric dimensions and high aspect ratio which give high surface area available for exposure to sensing material. Various materials can be used for this purpose to probe physical (light intensity, temperature etc.), chemical (humidity, ammonia gas, alcohol etc.) or biological (germs, hormones etc.) parameters. The present work involves the application of TEMPOS structures as humidity sensors. The sample to be studied was prepared using the polymer electrolyte (PEO/NH4ClO4) with CdS nano-particles dispersed in the polymer electrolyte. In the present research we have attempted to correlate the combined effects of voltage and frequency on impedance of humidity sensors using a neural network model and results have indicated that the mean absolute error of the ANN Model for the training data was 3.95% while for the validation data it was 4.65%. The corresponding values for the LR model were 8.28% and 8.35% respectively. It was also demonstrated the percentage improvement of the ANN Model with respect to the

  17. Live cell imaging combined with high-energy single-ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Na; Du, Guanghua, E-mail: gh-du@impcas.ac.cn; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Guo, Jinlong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Northwest Normal University, Lanzhou (China); Chen, Hao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Institute of Nuclear Science and Technology, University of Lanzhou, Lanzhou (China)

    2016-03-15

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10{sup −3} s{sup −1} and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10{sup −2} s{sup −1}.

  18. Live cell imaging combined with high-energy single-ion microbeam

    International Nuclear Information System (INIS)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe; Guo, Jinlong; Chen, Hao

    2016-01-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10"−"3 s"−"1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10"−"2 s"−"1.

  19. Trapped-ion anomalous diffusion coefficient on the basis of single mode saturation

    International Nuclear Information System (INIS)

    Koshi, Yuji; Hatayama, Akiyoshi; Ogasawara, Masatada.

    1982-03-01

    Expressions of the anomalous diffusion coefficient due to the dissipative trapped ion instability (DTII) are derived for the case with and without the effect of magnetic shear. Derivation is made by taking into account of the single mode saturation of the DTII previously obtained numerically. In the absence of the shear effect, the diffusion coefficient is proportional to #betta#sub(i)a 2 (#betta#sub(i) is the effective collision frequency of the trapped ions and a is the minor radius of a torus) and is much larger than the neoclassical ion heat conductivity. In the presence of the shear effect, the diffusion coefficient is much smaller than the Kadomtsev and Pogutse's value and is the same order of magnitude as the neoclassical ion heat conductivity. Dependences of the diffusion coefficient on the temperature and on the total particle number density are rather complicated due to the additional spectral cut-off, which is introduced to regularize the short wavelength modes in the numerical analysis. (author)

  20. Live cell imaging combined with high-energy single-ion microbeam

    Science.gov (United States)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Guo, Jinlong; Wu, Ruqun; Chen, Hao; Wei, Junzhe

    2016-03-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10-3 s-1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10-2 s-1.

  1. A novel method for observation by unaided eyes of nitrogen ion tracks and angular distribution in a plasma focus device using 50 Hz–HV electrochemically-etched polycarbonate detectors

    International Nuclear Information System (INIS)

    Sohrabi, M.; Habibi, M.; Roshani, G.H.; Ramezani, V.

    2012-01-01

    A novel ion detection method has been developed and studied in this paper for the first time to detect and observe tracks of nitrogen ions and their angular distribution by unaided eyes in the Amirkabir 4 kJ plasma focus device (PFD). The method is based on electrochemical etching (ECE) of nitrogen ion tracks in 1 mm thick large area polycarbonate (PC) detectors. The ECE method employed a specially designed and constructed large area ECE chamber by applying a 50 Hz–high voltage (HV) generator under optimized ECE conditions. The nitrogen ion tracks and angular distribution were efficiently (constructed for this study) amplified to a point observable by the unaided eyes. The beam profile and angular distribution of nitrogen ion tracks in the central axes of the beam and two- and three-dimensional iso-ion track density distributions showing micro-beam spots were determined. The distribution of ion track density along the central axes versus angular position shows double humps around a dip at the 0° angular positions. The method introduced in this paper proved to be quite efficient for ion beam profile and characteristic studies in PFDs with potential for ion detection studies and other relevant dosimetry applications.

  2. Imaging Action Potential in Single Mammalian Neurons by Tracking the Accompanying Sub-Nanometer Mechanical Motion.

    Science.gov (United States)

    Yang, Yunze; Liu, Xian-Wei; Wang, Hui; Yu, Hui; Guan, Yan; Wang, Shaopeng; Tao, Nongjian

    2018-03-28

    Action potentials in neurons have been studied traditionally by intracellular electrophysiological recordings and more recently by the fluorescence detection methods. Here we describe a label-free optical imaging method that can measure mechanical motion in single cells with a sub-nanometer detection limit. Using the method, we have observed sub-nanometer mechanical motion accompanying the action potential in single mammalian neurons by averaging the repeated action potential spikes. The shape and width of the transient displacement are similar to those of the electrically recorded action potential, but the amplitude varies from neuron to neuron, and from one region of a neuron to another, ranging from 0.2-0.4 nm. The work indicates that action potentials may be studied noninvasively in single mammalian neurons by label-free imaging of the accompanying sub-nanometer mechanical motion.

  3. An efficient fluorescent single-particle position tracking system for long-term pulsed measurements of nitrogen-vacancy centers in diamond

    Science.gov (United States)

    Kim, Kiho; Yun, Jiwon; Lee, Donghyuck; Kim, Dohun

    2018-02-01

    A simple and convenient design enables real-time three-dimensional position tracking of nitrogen-vacancy (NV) centers in diamond. The system consists entirely of commercially available components (a single-photon counter, a high-speed digital-to-analog converter, a phase-sensitive detector-based feedback device, and a piezo stage), eliminating the need for custom programming or rigorous optimization processes. With a large input range of counters and trackers combined with high sensitivity of single-photon counting, high-speed position tracking (upper bound recovery time of 0.9 s upon 250 nm of step-like positional shift) not only of bright ensembles, but also of low-photon-collection-efficiency single to few NV centers (down to 103 s-1) is possible. The tracking requires position modulation of only 10 nm, which allows simultaneous position tracking and pulsed measurements in the long term. Therefore, this tracking system enables measuring a single-spin magnetic resonance and Rabi oscillations at a very high resolution even without photon collection optimization. The system is widely applicable to various fields related to NV center quantum manipulation research such as NV optical trapping, NV tracking in fluid dynamics, and biological sensing using NV centers inside a biological cell.

  4. Propensity rules for orientation in singly-charged ion-atom collisions

    International Nuclear Information System (INIS)

    Nielsen, S.E.; Dubois, A.; Hansen, J.P.

    1990-01-01

    Orientation effects for electron capture and excitation in singly-charged ion-atom collisions are analysed using the atomic basis impact parameter method with full inclusion of electron translational factors. We find that the orientation preferences previously predicted for excitation in terms of propensity rules may still be observed when capture is present in ion-atom collisions. Furthermore, in spite of intricate behaviour of the direct capture couplings during the collision, we draw some parallel conclusions for the orientation of the capture states. We illustrate these perturbative predictions by close-coupling calculations for H + -Na(3s) collisions where clear propensity for orientation of the H(2p) capture state is demonstrated in impact parameter and velocity dependences. Finally we predict pronounced orientation effects for H(2s) and H(2p) capture in collisions of H + with initially oriented Na(3p) states. (author)

  5. Quantum sensing of the phase-space-displacement parameters using a single trapped ion

    Science.gov (United States)

    Ivanov, Peter A.; Vitanov, Nikolay V.

    2018-03-01

    We introduce a quantum sensing protocol for detecting the parameters characterizing the phase-space displacement by using a single trapped ion as a quantum probe. We show that, thanks to the laser-induced coupling between the ion's internal states and the motion mode, the estimation of the two conjugated parameters describing the displacement can be efficiently performed by a set of measurements of the atomic state populations. Furthermore, we introduce a three-parameter protocol capable of detecting the magnitude, the transverse direction, and the phase of the displacement. We characterize the uncertainty of the two- and three-parameter problems in terms of the Fisher information and show that state projective measurement saturates the fundamental quantum Cramér-Rao bound.

  6. Raman spectroscopic investigations of swift heavy ion irradiation effects in single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Olejniczak, A.; Skuratov, V.A.; Lukaszewicz, J.P.

    2013-01-01

    In this study, we report the results on swift heavy ion irradiation effects in single-walled carbon nanotubes (SWNTs). Buckypapers, prepared of CVD grown, SWNTs were irradiated at room temperature with 167 MeV Xe ions to fluences in the range of 6×10 11 - 6.5×10 13 cm -2 and investigated using Raman spectroscopy. We observed a rich set of features in the intermediate frequency mode region. Some of them, being defect-induced, resembled fairly well the phonon density of states (DOS) of nanocrystalline glassy carbon. Analysis of the RBM modes has shown that the broader metallic tubes are characterized by higher radiation stability than thinner semiconducting ones. (authors)

  7. Ion feedback suppression using inclined MCP holes in a 'single-MCP+micromegas+pads' detector

    International Nuclear Information System (INIS)

    Va'vra, J.; Sumiyoshi, T.

    2005-01-01

    We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in the presence of a magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (microchannel plate), a micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

  8. Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

    DEFF Research Database (Denmark)

    Henriksen, L.; Johansen, A.; Koch, J.

    1968-01-01

    Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

  9. Evaluation of single tracks of 17-4PH steel manufactured at different power densities and scanning speeds by selective laser melting

    CSIR Research Space (South Africa)

    Moller, Hein

    2016-11-01

    Full Text Available In Selective Laser Melting, the initial units produced are single tracks that overlap to create a single layer; from the sequence of layers, a 3D object is manufactured. The properties of the parts produced by SLM depend heavily on the properties...

  10. An efficient single-step scheme for manipulating quantum information of two trapped ions beyond the Lamb-Dicke limit

    International Nuclear Information System (INIS)

    Wei, L.F.; Nori, Franco

    2003-01-01

    Based on the exact conditional quantum dynamics for a two-ion system, we propose an efficient single-step scheme for coherently manipulating quantum information of two trapped cold ions by using a pair of synchronous laser pulses. Neither the auxiliary atomic level nor the Lamb-Dicke approximation are needed

  11. Swift heavy ion induced single event upsets in high density UV-EPROM's

    Energy Technology Data Exchange (ETDEWEB)

    Dahiwale, S.S. [Department of Physics, University of Pune, Pune 7 (India); Shinde, N.S. [Department of Chemical Engineering, Mie University (Japan); Kanjilal, D. [Inter University Accelerator Center, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 7 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 7 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-04-15

    A few high density UV-EPROM's (32Kb x 8) were irradiated with 5.41 MeV energy {alpha}-particles with fluences from 10{sup 4} to 10{sup 8} alphas/cm{sup 2} and 100 MeV nickel, iodine and silver ions for low fluences between 5 x 10{sup 7} and 10{sup 8} ions/cm{sup 2}. The energy and ion species was selected on the basis of predicted threshold values of linear energy transfer (LET) in silicon. The program which was stored in the memory found to be changed from 0 to 1 and 1 to 0 state, respectively. On the basis of changed states, the cross-sections ({sigma}) were calculated to investigate the single event effects/upsets. No upset was observed in case of {alpha}-particle since it has very low LET, but the SEU cross-section found to be more in case of Iodine i.e. 2.29 x 10{sup -3} cm{sup 2} than that of nickel, 2.12 x 10{sup -3} cm{sup 2} and silver, 2.26 x 10{sup -3}. This mainly attributes that LET for iodine is more as compared to silver and nickel ions, which deposits large amount of energy near the sensitive node of memory cell in the form of electron-hole pairs required to change the state. These measured SEU cross-section were also compared with theoretically predicted values along with the Weibull distribution fit to the ion induced experimental SEU data. The theoretical predicted SEU cross-section 3.27 x 10{sup -3} cm{sup 2} found to be in good agreement with the measured SEU cross-section.

  12. Case study of a grid connected with a battery photovoltaic system: V-trough concentration vs. single-axis tracking

    International Nuclear Information System (INIS)

    Tina, G.M.; Scandura, P.F.

    2012-01-01

    Highlights: ► PV systems with sun tracking and concentrators (CPVS) can reduce the cost of energy per kWh produced. ► The V-trough low-concentration system solution is compatible with flat PV module technologies. ► Optical, thermal and electrical models are needed to forecast real power production. ► The description of a PV grid connected system with batteries, a one-axis tracker and CPV photovoltaic system is presented. ► Outdoor measurements of the generating system are provided and discussed. - Abstract: Photovoltaic systems (PVSs) combined with either some form of storage, such as a battery energy storage system (BESS), or direct load control, can play a crucial role in achieving a more economical operation of the electric utility system while enhancing its reliability with additional energy sources. At the same time, it is also important to use cost-effective PV solutions. In this context, a low-concentration PVS (CPVS) is analysed as a feasible alternative. This paper, present a case study of a complex PVS, composed of two PVSs, a storage system (BEES) and an inverter that allows the system to operate in both the island and grid-connected modes. The first PVS, is a 2.76-kWp single-axis tracking system (azimuth) with modules facing south and tilted 30°, while the second PVS is a dual-axis tracking system, rated 860 Wp, consisting of a concentrator at the flat mirrors (DoubleSun® Four). The system is installed on the roof of the main building of the “ITIS Marconi” school (Italy). A detailed description of the system is provided, and preliminary operating data are presented and discussed. The efficiencies of the PV systems are calculated and measured to evaluate the cost effectiveness of a low-concentration system.

  13. Electrical characterization of single cells using polysilicon wire ion sensor in an isolation window.

    Science.gov (United States)

    Wu, You-Lin; Hsu, Po-Yen; Hsu, Chung-Ping; Wang, Chih-Cheng; Lee, Li-Wen; Lin, Jing-Jenn

    2011-10-01

    A polysilicon wire (PSW) sensor can detect the H(+) ion density (pH value) of the medium coated on its surface, and different cells produce different extracellular acidification and hence different H(+) ion densities. Based on this, we used a PSW sensor in combination with a mold-cast polydimethylsiloxane (PDMS) isolation window to detect the adhesion, apoptosis and extracellular acidification of single normal cells and single cancer cells. Single living human normal cells WI38, MRC5, and BEAS-2B as well as non-small-cell lung cancer (NSCLC) cells A549, H1299, and CH27 were cultivated separately inside the isolation window. The current flowing through the PSW channel was measured. From the PSW channel current change as a function of time, we determined the cell adhesion time by observing the time required for the current change to saturate, since a stable extracellular ion density was established after the cells were completely adhered to the PSW surface. The apoptosis of cells can also be determined when the channel current change drops to zero. We found that all the NSCLC cells had a higher channel current change and hence a lower pH value than the normal cells anytime after they were seeded. The corresponding average pH values were 5.86 for A549, 6.00 for H1299, 6.20 for CH27, 6.90 for BEAS-2B, 6.96for MRC5, and 7.02 for WI38, respectively, after the cells were completely adhered to the PSW surface. Our results show that NSCLC cells have a stronger cell-substrate adhesion and a higher extracellular acidification rate than normal cells.

  14. Subattoampere current induced by single ions in silicon oxide layers of nonvolatile memory cells

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Larcher, L.; Visconti, A.; Bonanomi, M.

    2006-01-01

    A single ion impinging on a thin silicon dioxide layer generates a number of electron/hole pairs proportional to its linear energy transfer coefficient. Defects generated by recombination can act as a conductive path for electrons that cross the oxide barrier, thanks to a multitrap-assisted mechanism. We present data on the dependence of this phenomenon on the oxide thickness by using floating gate memory arrays. The tiny number of excess electrons stored in these devices allows for extremely high sensitivity, impossible with any direct measurement of oxide leakage current. Results are of particular interest for next generation devices

  15. Effects of ion beam heating on Raman spectra of single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Hulman, Martin; Skakalova, Viera; Krasheninnikov, A. V.; Roth, S.

    2009-01-01

    Free standing films of single-wall carbon nanotubes were irradiated with energetic N + and C 4+ ions. The observed changes in the Raman line shape of the radial breathing mode and the G band of the C 4+ irradiated samples were similar to those found for a thermally annealed sample. We ascribe these changes to thermal desorption of volatile dopants from the initially doped nanotubes. A simple geometry of the experiment allows us to estimate the temperature rise by one-dimensional heat conductance equation. The calculation indicates that irradiation-mediated increase in temperature may account for the observed Raman spectra changes

  16. Quantum Heisenberg antiferromagnetic chains with exchange and single-ion anisotropies

    International Nuclear Information System (INIS)

    Peters, D; Selke, W; McCulloch, I P

    2010-01-01

    Using density matrix renormalization group calculations, ground state properties of the spin-1 Heisenberg chain with exchange and quadratic single-ion anisotropies in an external field are studied, for special choices of the two kinds of anisotropies. In particular, the phase diagram includes antiferromagnetic, spin-liquid (or spin-flop), IS2, and supersolid (or biconical) phases. Especially, new features of the spin-liquid and supersolid phases are discussed. Properties of the quantum chains are compared to those of corresponding classical spin chains.

  17. Single charged-particle damage to living cells: a new method based on track-etch detectors

    International Nuclear Information System (INIS)

    Durante, M.; Grossi, G.F.; Pugliese, M.; Manti, L.; Nappo, M.; Gialanella, G.

    1994-01-01

    Biological effects of ionizing radiation are usually expressed as a function of the absorbed dose. Low doses of high-LET radiation correspond to one or few particle traversals through the cell. In order to study the biological effectiveness of single charged particles, we have developed a new method based on solid state nuclear track detectors. Cells are seeded on mylar and a LR-115 film is stuck below the mylar base. After irradiation, the LR-115 film is etched and cells observed at a phase contrast microscope connected to a video camera and an image analyzer. In this way, it is possible to measure the number of traversals through the cell nucleus or cytoplasm. Coordinates of each cell on the microscope bench are saved. After incubation for about one week, cells are fixed and stained and the colonies observed at the microscope. The fate of each irradiated cell is therefore correlated to the number of traversals. We have tested this method with two different rodent embryo fibroblast cell lines, C3H 10T1/2 and V79, exposed to 3.2 MeV accelerated α-particles (LET =124 keV/μm). The studied endpoint was cell killing. Preliminary biological results suggest that few α-particle tracks in V79 hamster cells are sufficient to reduce surviving fraction. ((orig.))

  18. CyberKnife with Tumor Tracking: An Effective Treatment for High-Risk Surgical Patients with Single Peripheral Lung Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Snider, James W.; Oermann, Eric K.; Chen, Viola; Rabin, Jennifer; Suy, Simeng; Yu, Xia [Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); Vahdat, Saloomeh [Department of Pathology, Georgetown University Hospital, Washington, DC (United States); Collins, Sean P. [Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); Banovac, Filip [Department of Radiology, Georgetown University Hospital, Washington, DC (United States); Anderson, Eric [Division of Pulmonary, Critical Care and Sleep Medicine, Georgetown University Hospital, Washington, DC (United States); Collins, Brian T., E-mail: collinsb@gunet.georgetown.edu [Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States)

    2012-06-29

    Standard treatment for operable patients with single peripheral lung metastases is metastasectomy. We report mature CyberKnife outcomes for high-risk surgical patients with biopsy proven single peripheral lung metastases. Twenty-four patients (median age 73 years) with a mean maximum tumor diameter of 2.5 cm (range, 0.8–4.5 cm) were treated over a 6-year period extending from September 2004 to September 2010 and followed for a minimum of 1 year or until death. A mean dose of 52 Gy (range, 45–60 Gy) was delivered to the prescription isodose line in three fractions over a 3–11 day period (mean, 7 days). At a median follow-up of 20 months, the 2-year Kaplan–Meier local control and overall survival rates were 87 and 50%, respectively. CyberKnife with fiducial tracking is an effective treatment for high-risk surgical patients with single small peripheral lung metastases. Trials comparing CyberKnife with metastasectomy for operable patients are necessary to confirm equivalence.

  19. Empirical reconstruction and long-duration tracking of the magnetospheric boundary in single- and multi-spacecraft contexts

    Directory of Open Access Journals (Sweden)

    J. De Keyser

    2005-06-01

    Full Text Available The magnetospheric boundary is always moving, making it difficult to establish its structure. This paper presents a novel method for tracking the motion of the boundary, based on in-situ observations of the plasma velocity and of one or more additional observables. This method allows the moving boundary to be followed for extended periods of time (up to several hours and aptly deals with limitations on the time resolution of the data, with measurement errors, and with occasional data gaps; it can exploit data from any number of spacecraft and any type of instrument. At the same time the method is an empirical reconstruction technique that determines the one-dimensional spatial structure of the boundary. The method is illustrated with single- and multi-spacecraft applications using data from Ampte/Irm and Cluster.

  20. Lipid diffusion in the distal and proximal leaflets of supported lipid bilayer membranes studied by single particle tracking

    Science.gov (United States)

    Schoch, Rafael L.; Barel, Itay; Brown, Frank L. H.; Haran, Gilad

    2018-03-01

    Supported lipid bilayers (SLBs) have been studied extensively as simple but powerful models for cellular membranes. Yet, potential differences in the dynamics of the two leaflets of a SLB remain poorly understood. Here, using single particle tracking, we obtain a detailed picture of bilayer dynamics. We observe two clearly separate diffusing populations, fast and slow, that we associate with motion in the distal and proximal leaflets of the SLB, respectively, based on fluorescence quenching experiments. We estimate diffusion coefficients using standard techniques as well as a new method based on the blur of images due to motion. Fitting the observed diffusion coefficients to a two-leaflet membrane hydrodynamic model allows for the simultaneous determination of the intermonolayer friction coefficient and the substrate-membrane friction coefficient, without any prior assumptions on the strengths of the relevant interactions. Remarkably, our calculations suggest that the viscosity of the interfacial water confined between the membrane and the substrate is elevated by ˜104 as compared to bulk water. Using hidden Markov model analysis, we then obtain insight into the transbilayer movement of lipids. We find that lipid flip-flop dynamics are very fast, with half times in the range of seconds. Importantly, we find little evidence for membrane defect mediated lipid flip-flop for SLBs at temperatures well above the solid-to-liquid transition, though defects seem to be involved when the SLBs are cooled down. Our work thus shows that the combination of single particle tracking and advanced hydrodynamic modeling provides a powerful means to obtain insight into membrane dynamics.

  1. Detecting carbon uptake and cellular allocation by individual algae in multispecies assemblages: Tracking carbon into single algal cells

    Energy Technology Data Exchange (ETDEWEB)

    Murdock, Justin N. [USDA Agricultural Research Service, National Sedimentation Laboratory, Oxford Mississippi; Department of Biology, Tennessee Technological University, Cookeville Tennessee

    2015-11-03

    Algal species vary in carbon (C) need and uptake rates. Understanding differences in C uptake and cellular allocation among species from natural communities will bring new insight into many ecosystem process questions including how species changes will alter energy availability and C sequestration in aquatic ecosystems. A major limitation of current methods that measure algal C incorporation is the inability to separate the response of individual species from mixed-species assemblages. I used Fourier-transform infrared microspectroscopy to qualitatively measure inorganic 13C isotope incorporation into individual algal cells in single species, two species, and natural phytoplankton assemblages. Lateral shifts in spectral peaks from 13C treatments were observed in all species. Comparison of peaks associated with carbohydrates, proteins, and lipids allowed for the detection of which individuals took in C, and which macromolecules the C was used to make. For example, shifts in Spirogyra spectral peaks showed substantial C incorporation in carbohydrates. Further, shifts in peaks at 1160 cm-1, 1108 cm-1, 1080 cm-1, 1048 cm-1, and 1030 cm-1 suggested C was being allocated into cellulose. The natural phytoplankton assemblage demonstrated how C could be tracked into co-occurring species. A diatom had large shifts in protein and carbohydrate peaks, while a green alga and euglenoid had only a few shifts in protein related peaks. Fourier-transform infrared microspectroscopy is an established, label free method for measuring the chemical composition of algal cells. However, adding a label such as 13C isotope can greatly expand the technique's capabilities by qualitatively tracking C movement between inorganic and organic states within single cells.

  2. Polarization bremsstrahlung of a hydrogen-like ion in a single crystal

    International Nuclear Information System (INIS)

    Astapenko, V. A.

    2009-01-01

    Polarization bremsstrahlung (PB) that arises when a fast hydrogen-like ion is scattered in a single crystal is investigated theoretically. Four types of the process are analyzed that are caused by virtual excitation of electrons of the target and of the incident particle (IP), as well as by a coherent and incoherent interaction between the IP and the single crystal. The spectral, angular, and velocity (of the IP) characteristics of PB are calculated with regard to the spectral function of a photodetector. Optimal observation conditions and regions in which different types of PB are dominant are determined, and the dependence of these regions on the charge of the IP nucleus and of the target atoms is revealed

  3. High-fidelity state detection and tomography of a single-ion Zeeman qubit

    International Nuclear Information System (INIS)

    Keselman, A; Glickman, Y; Akerman, N; Kotler, S; Ozeri, R

    2011-01-01

    We demonstrate high-fidelity Zeeman qubit state detection in a single trapped 88 Sr + ion. Qubit readout is performed by shelving one of the qubit states to a metastable level using a narrow linewidth diode laser at 674 nm, followed by state-selective fluorescence detection. The average fidelity reached for the readout of the qubit state is 0.9989(1). We then measure the fidelity of state tomography, averaged over all possible single-qubit states, which is 0.9979(2). We also fully characterize the detection process using quantum process tomography. This readout fidelity is compatible with recent estimates of the detection error threshold required for fault-tolerant computation, whereas high-fidelity state tomography opens the way for high-precision quantum process tomography.

  4. High-fidelity state detection and tomography of a single-ion Zeeman qubit

    Energy Technology Data Exchange (ETDEWEB)

    Keselman, A; Glickman, Y; Akerman, N; Kotler, S; Ozeri, R, E-mail: ozeri@weizmann.ac.il [Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2011-07-15

    We demonstrate high-fidelity Zeeman qubit state detection in a single trapped {sup 88}Sr{sup +} ion. Qubit readout is performed by shelving one of the qubit states to a metastable level using a narrow linewidth diode laser at 674 nm, followed by state-selective fluorescence detection. The average fidelity reached for the readout of the qubit state is 0.9989(1). We then measure the fidelity of state tomography, averaged over all possible single-qubit states, which is 0.9979(2). We also fully characterize the detection process using quantum process tomography. This readout fidelity is compatible with recent estimates of the detection error threshold required for fault-tolerant computation, whereas high-fidelity state tomography opens the way for high-precision quantum process tomography.

  5. Experimental Verification of a Jarzynski-Related Information-Theoretic Equality by a Single Trapped Ion.

    Science.gov (United States)

    Xiong, T P; Yan, L L; Zhou, F; Rehan, K; Liang, D F; Chen, L; Yang, W L; Ma, Z H; Feng, M; Vedral, V

    2018-01-05

    Most nonequilibrium processes in thermodynamics are quantified only by inequalities; however, the Jarzynski relation presents a remarkably simple and general equality relating nonequilibrium quantities with the equilibrium free energy, and this equality holds in both the classical and quantum regimes. We report a single-spin test and confirmation of the Jarzynski relation in the quantum regime using a single ultracold ^{40}Ca^{+} ion trapped in a harmonic potential, based on a general information-theoretic equality for a temporal evolution of the system sandwiched between two projective measurements. By considering both initially pure and mixed states, respectively, we verify, in an exact and fundamental fashion, the nonequilibrium quantum thermodynamics relevant to the mutual information and Jarzynski equality.

  6. Electron paramagnetic resonance and optical absorption of uranium ions diluted in CdF2 single crystals

    International Nuclear Information System (INIS)

    Pereira, J.J.C.R.

    1976-08-01

    The electron paramagnetic resonance (EPR) has been studied in conection with the optical absortion spectra of Uranium ions diluted in CdF 2 single crystals. Analyses of the EPR and optical absorption spectra obtained experimentally, and a comparison with known results in the isomorfic CaF 2 , SrF 2 and BaF 2 , allowed the identification of two paramagnetic centers associated with Uranium ions. These are the U(2+) ion in cubic symmetry having the triplet γ 5 as ground state, and the U(3+) ion in cubic symmetry having the dublet γ 6 as ground state. (Author) [pt

  7. Development of the IFJ single ion hit facility for cells irradiation

    International Nuclear Information System (INIS)

    Veselov, O.; Polak, W.; Ugenskiene, R.; Hajduk, R.; Lebed, K.; Lekki, J.; Horwacik, T.; Dutkiewicz, E.M.; Maranda, S.; Pieprzyca, T.; Sarnecki, C.; Stachura, Z.; Szklarz, Z.; Styczen, J.

    2005-12-01

    In recent years a single ion hit facility (SIHF) has been constructed at the IFJ ion microprobe. The setup is used for the precise irradiations of living cells by a controlled number of ions. The facility allows investigations in various aspects of biomedical research, such as adaptive response, bystander effect, inverse dose-rate effect, low-dose hypersensitivity, etc. Those investigations have two very important requirements: (i) cells must be examined in their natural state and environment, i.e. without previously being killed, and preferentially, neither fixed nor stained, and (ii) a possibility of automatic irradiation of large number of cells with a computer recognition of their positions must be provided. This work presents some of the crucial features of the off-line and on-line optical systems, including self-developed software responsible for the automatic cell recognition. We also show several tests carried out to determine the efficiency of the whole setup and some segments. In conclusion, the results of our first irradiation measurements performed with living cells are demonstrated. (author)

  8. Nanomechanical investigation of ion implanted single crystals - Challenges, possibilities and pitfall traps related to nanoindentation

    Science.gov (United States)

    Kurpaska, Lukasz

    2017-10-01

    Nanoindentation technique have developed considerably over last thirty years. Nowadays, commercially available systems offer very precise measurement in nano- and microscale, environmental noise cancelling (or at least noise suppressing), in situ high temperature indentation in controlled atmosphere and vacuum conditions and different additional options, among them dedicated indentation is one of the most popular. Due to its high precision, and ability to measure mechanical properties from very small depths (tens of nm), this technique become quite popular in the nuclear society. It is known that ion implantation (to some extent) can simulate the influence of neutron flux. However, depth of the material damage is very limited resulting in creation of thin layer of modified material over unmodified bulk. Therefore, only very precise technique, offering possibility to control depth of the measurement can be used to study functional properties of the material. For this reason, nanoindentation technique seems to be a perfect tool to investigate mechanical properties of ion implanted specimens. However, conducting correct nanomechanical experiment and extracting valuable mechanical parameters is not an easy task. In this paper a discussion about the nanoindentation tests performed on ion irradiated YSZ single crystal is presented. The goal of this paper is to discuss possible traps when studying mechanical properties of such materials and thin coatings.

  9. Complete momentum balance for single ionization of helium by fast ion impact: I. Experiment

    International Nuclear Information System (INIS)

    Moshammer, R.; Kollmus, H.; Unverzagt, M.; Schmidt-Boecking, H.; Wood, C.J.; Olson, R.E.

    1997-02-01

    The collision dynamics of He single ionization by 3.6 MeV/u Se 28+ impact was explored using the GSI-reaction microscope, a high resolution integrated multi electron - recoil-ion momentum spectrometer. The complete three particle final state momentum distribution (9 cartesian components p i ) was imaged with a resolution of Δp i ∼ ±0.1 a.u. by measuring the three momentum components of the emitted electron and the recoiling target-ion in coincidence. The projectile energy loss has been determined on a level of ΔE p /E p ∼ 10 -7 and projectile scattering angles as small as Δθ ∼ 10 -7 rad became accessible. The experimental data which are compared with results of classical trajectory Monte-Carlo (CTMC) calculations reveal an unprecedented insight into the details of the electron emission and the collision dynamics for ionization of helium by fast heavy-ion impact. (orig.)

  10. Complete momentum balance for single ionization of helium by fast ion impact: I. Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Moshammer, R.; Kollmus, H.; Unverzagt, M.; Schmidt-Boecking, H. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik; Ullrich, J.; Schmitt, W. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Wood, C.J.; Olson, R.E. [Missouri Univ., Rolla, MO (United States). Dept. of Physics

    1997-02-01

    The collision dynamics of He single ionization by 3.6 MeV/u Se{sup 28+} impact was explored using the GSI-reaction microscope, a high resolution integrated multi electron - recoil-ion momentum spectrometer. The complete three particle final state momentum distribution (9 cartesian components p{sub i}) was imaged with a resolution of {Delta}p{sub i} {approx} {+-}0.1 a.u. by measuring the three momentum components of the emitted electron and the recoiling target-ion in coincidence. The projectile energy loss has been determined on a level of {Delta}E{sub p}/E{sub p} {approx} 10{sup -7} and projectile scattering angles as small as {Delta}{theta} {approx} 10{sup -7}rad became accessible. The experimental data which are compared with results of classical trajectory Monte-Carlo (CTMC) calculations reveal an unprecedented insight into the details of the electron emission and the collision dynamics for ionization of helium by fast heavy-ion impact. (orig.)

  11. Designing Artificial Solid-Electrolyte Interphases for Single-Ion and High-Efficiency Transport in Batteries

    KAUST Repository

    Tu, Zhengyuan

    2017-09-21

    Substrates able to rectify transport of ions based on charge and/or size are ubiquitous in biological systems. Electrolytes and interphases that selectively transport electrochemically active ions are likewise of broad interest in all electrical energy storage technologies. In lithium-ion batteries, electrolytes with single- or near-single-ion conductivity reduce losses caused by ion polarization. In emergent lithium or sodium metal batteries, they maintain high conductivity at the anode and stabilize metal deposition by fundamental mechanisms. We report that 20- to 300-nm-thick, single-ion-conducting membranes deposited at the anode enable electrolytes with the highest combination of cation transference number, ionic conductivity, and electrochemical stability reported. By means of direct visualization we find that single-ion membranes also reduce dendritic deposition of Li in liquids. Galvanostatic measurements further show that the electrolytes facilitate long (3 mAh) recharge of full Li/LiNi0.8Co0.15Al0.05O2 (NCA) cells with high cathode loadings (3 mAh cm−2/19.9 mg cm−2) and at high current densities (3 mA cm−2).

  12. Single and binary adsorption of Cd (Ⅱ) and Zn (Ⅱ) ions from aqueous solutions onto bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Sukpreabprom, Hatairat; Arqueropanyo, Orn-anong; Naksata, Wimol; Janhom, Sorapong [Chiang Mai University, Chiang Mai (Thailand); Sooksamiti, Ponlayuth [The Office of Primary Industries and Mines Region 3, Chiang Mai (Thailand)

    2015-05-15

    Bottom ash, a waste obtained from coal-burning power plant, was used as a low cost adsorbent for the removal of Cd (Ⅱ) and Zn (Ⅱ) ions from single and binary systems in batch experiments. The results of adsorption capacity showed that bottom ash could be considered as a potential adsorbent. The uptake of Zn (Ⅱ) ion was greater than that of Cd (Ⅱ) ion. For single adsorption, based on the correlation coefficient (R{sup 2}) values, both Langmuir and Freundlich isotherms suitably described the adsorption equilibrium data in the initial metal ion concentration range of 10-50 mg/L. The multicomponent isotherms, including the extended Langmuir and IAST-Freundlich isotherms, were used to predict the binary adsorption of Cd (Ⅱ) and Zn (Ⅱ) ions. Furthermore, the appropriate multicomponent isotherm was investigated by minimizing the average relative error (ARE) function. It should be confirmed that the extended Langmuir isotherm fitted the binary adsorption equilibrium data satisfactorily.

  13. Growth and morphological analysis of segmented AuAg alloy nanowires created by pulsed electrodeposition in ion-track etched membranes

    Directory of Open Access Journals (Sweden)

    Ina Schubert

    2015-06-01

    Full Text Available Background: Multicomponent heterostructure nanowires and nanogaps are of great interest for applications in sensorics. Pulsed electrodeposition in ion-track etched polymer templates is a suitable method to synthesise segmented nanowires with segments consisting of two different types of materials. For a well-controlled synthesis process, detailed analysis of the deposition parameters and the size-distribution of the segmented wires is crucial.Results: The fabrication of electrodeposited AuAg alloy nanowires and segmented Au-rich/Ag-rich/Au-rich nanowires with controlled composition and segment length in ion-track etched polymer templates was developed. Detailed analysis by cyclic voltammetry in ion-track membranes, energy-dispersive X-ray spectroscopy and scanning electron microscopy was performed to determine the dependency between the chosen potential and the segment composition. Additionally, we have dissolved the middle Ag-rich segments in order to create small nanogaps with controlled gap sizes. Annealing of the created structures allows us to influence their morphology.Conclusion: AuAg alloy nanowires, segmented wires and nanogaps with controlled composition and size can be synthesised by electrodeposition in membranes, and are ideal model systems for investigation of surface plasmons.

  14. Ion implantation effects in single crystal Si investigated by Raman spectroscopy

    International Nuclear Information System (INIS)

    Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

    2009-01-01

    A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

  15. Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate

    International Nuclear Information System (INIS)

    Sun Xiaoguang; Hou Jun; Kerr, John B.

    2005-01-01

    Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li + salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE 8 -co-E 3 SO 3 Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE 8 -g-E n SO 3 Li, n = 2, 3). The highest conductivity at 25 deg. C of 2.0 x 10 -7 S cm -1 was obtained for the PAE 8 -co-E 3 SO 3 Li with a salt concentration of EO/Li = 40. The conductivity of PAE 8 -g-E 3 SO 3 Li is lower than that of PAE 8 -co-E 3 SO 3 Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li + . The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE 8 -g-E 2 SO 3 Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 μA cm -2 at 85 deg. C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer

  16. Moving scanning emitter tracking by a single observer using time of interception: Observability analysis and algorithm

    Directory of Open Access Journals (Sweden)

    Yifei ZHANG

    2017-06-01

    Full Text Available The target motion analysis (TMA for a moving scanning emitter with known fixed scan rate by a single observer using the time of interception (TOI measurements only is investigated in this paper. By transforming the TOI of multiple scan cycles into the direction difference of arrival (DDOA model, the observability analysis for the TMA problem is performed. Some necessary conditions for uniquely identifying the scanning emitter trajectory are obtained. This paper also proposes a weighted instrumental variable (WIV estimator for the scanning emitter TMA, which does not require any initial solution guess and is closed-form and computationally attractive. More importantly, simulations show that the proposed algorithm can provide estimation mean square error close to the Cramer-Rao lower bound (CRLB at moderate noise levels with significantly lower estimation bias than the conventional pseudo-linear least square (PLS estimator.

  17. The INFN-LNL single-ion horizontal microbeam facility for cell irradiation

    International Nuclear Information System (INIS)

    Gerardi, S.; Galeazzi, G.; Cherubini, R.

    2003-01-01

    Full text: Charged particle microbeams provide a unique method to control precisely the dose and its localisation within the cell. Such a kind of tool allows studying a number of important radiobiological processes in ways that cannot be achieved using conventional broad beam irradiation, which has the inherent experimental limitation imposed by the random Poisson-distributed particle hitting. We have designed and developed an apparatus for the micro-collimation in air of low-energy light ion beams, able to deliver targeted and counted particles to individual cells with an overall spatial resolution of few micrometers. The apparatus has been built up at the 7MV Van de Graaff CN accelerator, delivering protons, deuterons, helium-3 and helium-4 ion beams in an LET range from 7 to 180 keV/μm. The beam section is reduced down to 3-7 μm 2 by means of a tantalum pinhole microcollimator. A semi-automatic cell visualization and an automatic cell positioning and (after irradiation) cell revisiting system, based on an inverted phase contrast optical microscope and on X-Y micro-positioning stages with 0.1μm positioning precision, has been developed. Cell recognition is performed without using fluorescent staining and UV light. Particle detection in air is based on a silicon detector while beam profile and precise hit position measurements are accomplished by a high resolution and high sensibility cooled-CCD camera and Solid State Nuclear Track detectors, respectively. A dedicated software program, CELLView named, has been developed by using the LabView 6.0 package (National Instruments) to control all the irradiation protocol operations of sample holder movement, cell visualization, image acquisition and processing, cell data logging, cell positioning and revisiting. Facility performances and preliminary experimental results will be presented

  18. Investigation of optical properties of Cu/Ni multilayer nanowires embedded in etched ion-track template

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Lu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yao, Huijun, E-mail: Yaohuijun@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Duan, Jinglai; Chen, Yonghui [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lyu, Shuangbao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Maaz, Khan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore 45650, Islamabad (Pakistan); Mo, Dan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, Jie, E-mail: J.Liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, Youmei; Hou, Mingdong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-12-01

    Graphical abstract: The schematic diagram of measurement of extinction spectra of Cu/Ni multilayer nanowire arrays embedded in the template after removing the gold/copper substrate. - Highlights: • The optical properties of Cu/Ni multilayer nanowire arrays were first investigated by UV/Vis/NIR spectrometer and it was confirmed that the extinction peaks strongly related to the periodicity of the multilayer nanowire. • The Ni segment was thought as a kind of impurity which can change the surface electron distribution and thereby the extinction peaks of nanowire. • Current work supplied the clear layer thickness information of Cu and Ni in Cu/Ni multilayer nanowire with TEM and EDS line-scan profile analysis. - Abstract: For understanding the interaction between light and noble/magnetism multilayer nanowires, Cu/Ni multilayer nanowires are fabricated by a multi-potential step deposition technique in etched ion-track polycarbonate template. The component and the corresponding layer thickness of multilayer nanowire are confirmed by TEM and EDS line-scan analysis. By tailoring the nanowire diameter, the Cu layer thickness and the periodicity of the nanowire, the extinction spectral of nanowire arrays exhibit an extra sensitivity to the change of structural parameters. The resonance wavelength caused by surface plasmon resonance increases obviously with increasing the nanowire diameter, the Cu layer thickness and the periodicity. The observations in our work can be explained by the “impurity effect” and coupled effect and can also be optimized for developing optical devices based on multilayer nanowires.

  19. Single-molecule tracking of small GTPase Rac1 uncovers spatial regulation of membrane translocation and mechanism for polarized signaling

    Science.gov (United States)

    Das, Sulagna; Yin, Taofei; Yang, Qingfen; Zhang, Jingqiao; Wu, Yi I.; Yu, Ji

    2015-01-01

    Polarized Rac1 signaling is a hallmark of many cellular functions, including cell adhesion, motility, and cell division. The two steps of Rac1 activation are its translocation to the plasma membrane and the exchange of nucleotide from GDP to GTP. It is, however, unclear whether these two processes are regulated independent of each other and what their respective roles are in polarization of Rac1 signaling. We designed a single-particle tracking (SPT) method to quantitatively analyze the kinetics of Rac1 membrane translocation in living cells. We found that the rate of Rac1 translocation was significantly elevated in protrusions during cell spreading on collagen. Furthermore, combining FRET sensor imaging with SPT measurements in the same cell, the recruitment of Rac1 was found to be polarized to an extent similar to that of the nucleotide exchange process. Statistical analysis of single-molecule trajectories and optogenetic manipulation of membrane lipids revealed that Rac1 membrane translocation precedes nucleotide exchange, and is governed primarily by interactions with phospholipids, particularly PI(3,4,5)P3, instead of protein factors. Overall, the study highlights the significance of membrane translocation in spatial Rac1 signaling, which is in addition to the traditional view focusing primarily on GEF distribution and exchange reaction. PMID:25561548

  20. Concerning the evidence for the formation of dicentric chromosomal aberrations by single tracks of very short-ranged radiations

    International Nuclear Information System (INIS)

    Brenner, D.J.; Zaider, M.

    1987-01-01

    A recent communication by Thacker et al. reported yields of chromosomal exchange aberrations in V79 hamster cells after irradiation by either 250-kVp x rays or carbon characteristic K x rays of energy 270 eV. These latter produce photoelectrons with ranges of less than 10 nm. Such a distance makes it prima facie unlikely that two chromosomes could be damaged by a single track with a significant frequency. Thacker et al., however, discuss the observed effective linear component of induction of chromosome exchanges by ultrasoft carbon x-rays, and are thus led to consider the possibility that only one chromosome needs to be damaged by radiation to lead to an exchange event. In this paper, the authors analyze the data of Thacker et al. using a simple model. For carbon x rays they take advantage of the fact that the cell nuclei are not subject to a distribution of specific energies, but will each undergo essentially the same number of photon absorption events (each consisting of an energy deposition of 270 eV) for a given dose. They define the probability that a given chromosome will be broken as a result of an energy deposition event. They further define the probability that two chromosomes will be broken as a result of a single energy deposition event

  1. Single Particle Tracking reveals two distinct environments for CD4 receptors at the surface of living T lymphocytes

    International Nuclear Information System (INIS)

    Mascalchi, Patrice; Lamort, Anne Sophie; Salomé, Laurence; Dumas, Fabrice

    2012-01-01

    Highlights: ► We studied the diffusion of single CD4 receptors on living lymphocytes. ► This study reveals that CD4 receptors have either a random or confined diffusion. ► The dynamics of unconfined CD4 receptors was accelerated by a temperature raise. ► The dynamics of confined CD4 receptors was unchanged by a temperature raise. ► Our results suggest the existence of two different environments for CD4 receptors. -- Abstract: We investigated the lateral diffusion of the HIV receptor CD4 at the surface of T lymphocytes at 20 °C and 37 °C by Single Particle Tracking using Quantum Dots. We found that the receptors presented two major distinct behaviors that were not equally affected by temperature changes. About half of the receptors showed a random diffusion with a diffusion coefficient increasing upon raising the temperature. The other half of the receptors was permanently or transiently confined with unchanged dynamics on raising the temperature. These observations suggest that two distinct subpopulations of CD4 receptors with different environments are present at the surface of living T lymphocytes.

  2. Single-nanotube tracking reveals the nanoscale organization of the extracellular space in the live brain

    Science.gov (United States)

    Godin, Antoine G.; Varela, Juan A.; Gao, Zhenghong; Danné, Noémie; Dupuis, Julien P.; Lounis, Brahim; Groc, Laurent; Cognet, Laurent

    2017-03-01

    The brain is a dynamic structure with the extracellular space (ECS) taking up almost a quarter of its volume. Signalling molecules, neurotransmitters and nutrients transit via the ECS, which constitutes a key microenvironment for cellular communication and the clearance of toxic metabolites. The spatial organization of the ECS varies during sleep, development and aging and is probably altered in neuropsychiatric and degenerative diseases, as inferred from electron microscopy and macroscopic biophysical investigations. Here we show an approach to directly observe the local ECS structures and rheology in brain tissue using super-resolution imaging. We inject single-walled carbon nanotubes into rat cerebroventricles and follow the near-infrared emission of individual nanotubes as they diffuse inside the ECS for tens of minutes in acute slices. Because of the interplay between the nanotube geometry and the ECS local environment, we can extract information about the dimensions and local viscosity of the ECS. We find a striking diversity of ECS dimensions down to 40 nm, and as well as of local viscosity values. Moreover, by chemically altering the extracellular matrix of the brains of live animals before nanotube injection, we reveal that the rheological properties of the ECS are affected, but these alterations are local and inhomogeneous at the nanoscale.

  3. Effective tuning of the ratio of red to green emission of Ho"3"+ ions in single LiLuF_4 microparticle via codoping Ce"3"+ ions

    International Nuclear Information System (INIS)

    Gao, Wei; Dong, Jun; Liu, Jihong; Yan, Xuewen

    2016-01-01

    Yb"3"+/Ho"3"+ codoped LiLuF_4 microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF_4 microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF_4: Yb"3"+/Ho"3"+ microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce"3"+ ion concentrations of 12%, the ratio of red to green emission of the Ho"3"+ ions of single LiLuF_4 microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho"3"+ and Ce"3"+ ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho"3"+ in single LiLuF_4 microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

  4. Features of produced flows of multiply charged ions at interaction of laser radiation with single-component solids

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Bedilov, R.M.; Beysembaeva, H.B.; Sabitov, M.S.; Kamalova, J.O.

    2006-01-01

    Full text: The results of study features of formation multiply charged ions spectra of single-component solids depending on a target element composition in an interval of laser radiation power density q = 10 7 / 10 12 W/cm 2 with using of the laser multiply charged mass spectrometer [1] are given in this work. As single-component targets are used Be, B, C, Al, Ti, Fe, Co, Ni, Cu, Ag, Ta, W, Pt, Au as tablets in diameter of 10 mm and thickness of 3-5 mm. Analysis of the obtained mass-charge and energy spectra of multiply charged ions depending on a target element composition has allowed us to find features of formation spectra and escape multiply charged ions of a single-component targets. These features consist in characteristic changes: a threshold produced of ions; formation of mass-charge and energy spectra of multiply charged ions; nonlinear dependence of maximal charge number (Z max ) of ions from power density (q) of the laser; etc. Experimentally it was found that, with target atomic weight increase, threshold power of ions occurrence, nonlinearity ionization target structure, and intensity of ions, and energy spectra of ions increase. Let's note that, in case of targets Be, B, C, Al by laser radiation it is completely ionized and multiply charged ions and nuclei Be 4+ , B 5+ , C 6+ , Al 13+ are formed. The major level of ionization is attained in case of targets from Ti (Ti 17+ ) and Co (Co 18+ ). It is peculiar that structure formation and escape of multiply charged ion flows with Z max and nuclei depending on target element composition corresponds to various maximal values q of the laser. Increase of the maximal charge number of ions (atoms) observed with increase q of the laser for all investigated targets has nonlinear dependence in various levels that is especially shown beginning from q≥ 10 11 W/cm 2 . It is found that depending on target element composition multiply charged ions have a wide energy range with a maximum of allocation. With increase

  5. 2D speckle tracking echocardiography of the right ventricle free wall in SCUBA divers after single open sea dive.

    Science.gov (United States)

    Susilovic-Grabovac, Zora; Obad, Ante; Duplančić, Darko; Banić, Ivana; Brusoni, Denise; Agostoni, Piergiuseppe; Vuković, Ivica; Dujic, Zeljko; Bakovic, Darija

    2018-03-01

    The presence of circulating gas bubbles and their influence on pulmonary and right heart hemodynamics was reported after uncomplicated self-contained underwater breathing apparatus (SCUBA) dive(s). Improvements in cardiac imaging have recently focused great attention on the right ventricle (RV). The aim of our study was to evaluate possible effects of a single air SCUBA dive on RV function using 2D speckle tracking echocardiography in healthy divers after single open sea dive to 18 meters of seawater, followed by bottom stay of 47 minutes with a direct ascent to the surface. Twelve experienced male divers (age 39.5 ± 10.5 years) participated in the study. Echocardiographic assessment of the right ventricular function (free wall 2 D strain, tricuspid annular planes systolic excursion [TAPSE], lateral tricuspid annular peak systolic velocity [RV s`] and fractional area change [FAC]) was performed directly prior to and 30, 60, 90 and 120 minutes after surfacing. Two-dimensional strain of all three segments of free right ventricular wall showed a significant increase in longitudinal shortening in post-dive period for maximally 26% (basal), 15.4% (mid) and 16.3% (apical) as well as TAPSE (11.6%), RV FAC (19.2%), RV S` (12.7%) suggesting a rise in systolic function of right heart. Mean pulmonary arterial pressure (mean PAP) increased post-dive from 13.3 mmHg to maximally 23.5 mmHg (P = .002), indicating increased RV afterload. Our results demonstrated that single dive with significant bubble load lead to increase in systolic function and longitudinal strain of the right heart in parallel with increase in mean PAP. © 2017 John Wiley & Sons Australia, Ltd.

  6. How to resolve microsecond current fluctuations in single ion channels: The power of beta distributions

    Science.gov (United States)

    Schroeder, Indra

    2015-01-01

    Abstract A main ingredient for the understanding of structure/function correlates of ion channels is the quantitative description of single-channel gating and conductance. However, a wealth of information provided from fast current fluctuations beyond the temporal resolution of the recording system is often ignored, even though it is close to the time window accessible to molecular dynamics simulations. This kind of current fluctuations provide a special technical challenge, because individual opening/closing or blocking/unblocking events cannot be resolved, and the resulting averaging over undetected events decreases the single-channel current. Here, I briefly summarize the history of fast-current fluctuation analysis and focus on the so-called “beta distributions.” This tool exploits characteristics of current fluctuation-induced excess noise on the current amplitude histograms to reconstruct the true single-channel current and kinetic parameters. A guideline for the analysis and recent applications demonstrate that a construction of theoretical beta distributions by Markov Model simulations offers maximum flexibility as compared to analytical solutions. PMID:26368656

  7. Fully differential cross sections for the single ionization of helium by fast ions: Classical model calculations

    Science.gov (United States)

    Sarkadi, L.

    2018-04-01

    Fully differential cross sections (FDCSs) have been calculated for the single ionization of helium by 1- and 3-MeV proton and 100-MeV/u C6 + ion impact using the classical trajectory Monte Carlo (CTMC) method in the nonrelativistic, three-body approximation. The calculations were made employing a Wigner-type model in which the quantum-mechanical position distribution of the electron is approximated by a weighted integral of the microcanonical distribution over a range of the binding energy of the electron. In the scattering plane, the model satisfactorily reproduces the observed shape of the binary peak. In the region of the peak the calculated FDCSs agree well with the results of continuum-distorted-wave calculations for all the investigated collisions. For 1-MeV proton impact the experimentally observed shift of the binary peak with respect to the first Born approximation is compared with the shifts obtained by different higher-order quantum-mechanical theories and the present CTMC method. The best result was achieved by CTMC, but still a large part of the shift remained unexplained. Furthermore, it was found that the classical theory failed to reproduce the shape of the recoil peak observed in the experiments, it predicts a much narrower peak. This indicates that the formation of the recoil peak is dominated by quantum-mechanical effects. For 100-MeV/u C6 + ion impact the present CTMC calculations confirmed the existence of the "double-peak" structure of the angular distribution of the electron in the plane perpendicular to the momentum transfer, in accordance with the observation, the prediction of an incoherent semiclassical model, and previous CTMC results. This finding together with wave-packet calculations suggests that the "C6 + puzzle" may be solved by considering the loss of the projectile coherence. Experiments to be conducted using ion beams of anisotropic coherence are proposed for a more differential investigation of the ionization dynamics.

  8. Full characterization of laser-accelerated ion beams using Faraday cup, silicon carbide, and single-crystal diamond detectors

    Science.gov (United States)

    Margarone, D.; Krása, J.; Giuffrida, L.; Picciotto, A.; Torrisi, L.; Nowak, T.; Musumeci, P.; Velyhan, A.; Prokůpek, J.; Láska, L.; Mocek, T.; Ullschmied, J.; Rus, B.

    2011-05-01

    Multi-MeV beams of light ions have been produced using the 300 picosecond, kJ-class iodine laser, operating at the Prague Asterix Laser System facility in Prague. Real-time ion diagnostics have been performed by the use of various time-of-flight (TOF) detectors: ion collectors (ICs) with and without absorber thin films, new prototypes of single-crystal diamond and silicon carbide detectors, and an electrostatic ion mass spectrometer (IEA). In order to suppress the long photopeak induced by soft X-rays and to avoid the overlap with the signal from ultrafast particles, the ICs have been shielded with Al foil filters. The application of large-bandgap semiconductor detectors (>3 eV) ensured cutting of the plasma-emitted visible and soft-UV radiation and enhancing the sensitivity to the very fast proton/ion beams. Employing the IEA spectrometer, various ion species and charge states in the expanding laser-plasma have been determined. Processing of the experimental data based on the TOF technique, including estimation of the plasma fast proton maximum and peak energy, ion beam currents and total charge, total number of fast protons, as well as deconvolution processes, ion stopping power, and ion/photon transmission calculations for the different metallic filters used, are reported.

  9. Angle-resolved imaging of single-crystal materials with MeV helium ions

    Energy Technology Data Exchange (ETDEWEB)

    Strathman, M D; Baumann, S [Charles Evans and Associates, Redwood City, CA (United States)

    1992-02-01

    The simplest form of angle-resolved mapping for single-crystal materials is the creation of a channeling angular scan. Several laboratories have expanded this simple procedure to include mapping as a function of two independent tilts. These angle-resolved images are particularly suited to the assessment of crystal parameters including disorder, lattice location of impurities, and lattice stress. This paper will describe the use of the Charles Evans and Associates RBS-400 scattering chamber for acquisition, display, and analysis of angle-resolved images obtained from backscattered helium ions. Typical data acquisition times are 20 min for a {+-}2deg X-Y tilt scan with 2500 pixels (8/100deg resolution), and 10 nC per pixel. In addition, we will present a method for automatically aligning crystals for channeling measurements based on this imaging technology. (orig.).

  10. Focused ion beam milling of nanocavities in single colloidal particles and self-assembled opals

    International Nuclear Information System (INIS)

    Woldering, Leon A; Otter, A M; Husken, Bart H; Vos, Willem L

    2006-01-01

    We present a new method of realizing single nanocavities in individual colloidal particles on the surface of silicon dioxide artificial opals using a focused ion beam milling technique. We show that both the radius and the position of the nanocavity can be controlled with nanometre precision, to radii as small as 40 nm. The relation between the defect size and the milling time has been established. We confirmed that milling not only occurs on the surface of the spheres, but into and through them as well. We also show that an array of nanocavities can be fashioned. Structurally modified colloids have interesting potential applications in nanolithography, as well as in chemical sensing and solar cells, and as photonic crystal cavities

  11. Single Ion transient-IBIC analyses of semiconductor devices using a cryogenic temperature stage

    International Nuclear Information System (INIS)

    Laird, J.S.; Bardos, R.; Legge, G.J.F.; Jagadish, C.

    1998-01-01

    A new Transient - IBIC data acquisition and analysis system at MARC is described. A discussion on the need for single ion control and temperature control is also given. The recorded signal is used as the trigger for beam pulsing. The new cryostatic temperature control stage is introduced. Data is presented on line profiles across the edge of a Au-Si junction collected over the temperature range of 25-300K using a developed C-V and I-V variable temperature stage incorporating a liquid helium cryostat. It demonstrates the potential improvements in spatial resolution in materials of long lifetime by mapping on timing windows around the prompt charge component in the charge transient

  12. Electron capture to the continuum manifestation in fully differential cross sections for ion impact single ionization

    Science.gov (United States)

    Ciappina, M. F.; Fojón, O. A.; Rivarola, R. D.

    2018-04-01

    We present theoretical calculations of single ionization of He atoms by protons and multiply charged ions. The kinematical conditions are deliberately chosen in such a way that the ejected electron velocity matches the projectile impact velocity. The computed fully differential cross sections (FDCS) in the scattering plane using the continuum-distorted wave-eikonal initial state show a distinct peaked structure for a polar electron emission angle θ k = 0°. This element is absent when a first order theory is employed. Consequently, we can argue that this peak is a clear manifestation of a three-body effect, not observed before in FDCS. We discuss a possible interpretation of this new feature.

  13. Dynamics of a single ion in a perturbed Penning trap: Octupolar perturbation

    International Nuclear Information System (INIS)

    Lara, Martin; Salas, J. Pablo

    2004-01-01

    Imperfections in the design or implementation of Penning traps may give rise to electrostatic perturbations that introduce nonlinearities in the dynamics. In this paper we investigate, from the point of view of classical mechanics, the dynamics of a single ion trapped in a Penning trap perturbed by an octupolar perturbation. Because of the axial symmetry of the problem, the system has two degrees of freedom. Hence, this model is ideal to be managed by numerical techniques like continuation of families of periodic orbits and Poincare surfaces of section. We find that, through the variation of the two parameters controlling the dynamics, several periodic orbits emanate from two fundamental periodic orbits. This process produces important changes (bifurcations) in the phase space structure leading to chaotic behavior

  14. A single lithium-ion battery protection circuit with high reliability and low power consumption

    International Nuclear Information System (INIS)

    Jiang Jinguang; Li Sen

    2014-01-01

    A single lithium-ion battery protection circuit with high reliability and low power consumption is proposed. The protection circuit has high reliability because the voltage and current of the battery are controlled in a safe range. The protection circuit can immediately activate a protective function when the voltage and current of the battery are beyond the safe range. In order to reduce the circuit's power consumption, a sleep state control circuit is developed. Additionally, the output frequency of the ring oscillation can be adjusted continuously and precisely by the charging capacitors and the constant-current source. The proposed protection circuit is fabricated in a 0.5 μm mixed-signal CMOS process. The measured reference voltage is 1.19 V, the overvoltage is 4.2 V and the undervoltage is 2.2 V. The total power is about 9 μW. (semiconductor integrated circuits)

  15. Angle-resolved imaging of single-crystal materials with MeV helium ions

    International Nuclear Information System (INIS)

    Strathman, M.D.; Baumann, S.

    1992-01-01

    The simplest form of angle-resolved mapping for single-crystal materials is the creation of a channeling angular scan. Several laboratories have expanded this simple procedure to include mapping as a function of two independent tilts. These angle-resolved images are particularly suited to the assessment of crystal parameters including disorder, lattice location of impurities, and lattice stress. This paper will describe the use of the Charles Evans and Associates RBS-400 scattering chamber for acquisition, display, and analysis of angle-resolved images obtained from backscattered helium ions. Typical data acquisition times are 20 min for a ±2deg X-Y tilt scan with 2500 pixels (8/100deg resolution), and 10 nC per pixel. In addition, we will present a method for automatically aligning crystals for channeling measurements based on this imaging technology. (orig.)

  16. Luminescence of Bi3+ ions in Y3Al5O12:Bi single crystalline films

    International Nuclear Information System (INIS)

    Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Vistovsky, V.; Nedilko, S.; Nikl, M.

    2007-01-01

    The absorption and cathodoluminescence spectra of single crystalline films (SCF) of Y 3 Al 5 O 12 :Bi garnet depending on Bi concentration were analyzed. For consideration of the nature of the UV and visible Bi-related emission bands the time-resolved luminescence of Bi 3+ (ns 2 ) ions in YAG:Bi SCF was studied at 10 K under excitation by synchrotron radiation. The difference in the excitation spectra and emission decay of the UV and visible bands has been explained via radiative relaxation from the 3 P 1,0 excited states to the 1 S 0 ground state of the isolated and pair/clustered Bi 3+ emission centers in the garnet lattice, respectively

  17. Study of clean and ion bombardment damaged silver single crystal surfaces by work function measurements

    International Nuclear Information System (INIS)

    Chelvayohan, N.

    1982-06-01

    Work function values of the (110), (100) and (111) faces of silver single crystal were measured by the photoelectric emission method and found to be 4.14 +- 0.04 eV, 4.22 +-0.04 eV and 4.46 +- 0.02 eV respectively. Oxygen adsorption on the faces were studied by surface potential measurement. Strong oxygen adsorption was observed on (110) and (100) faces, whereas the (111) face was found to be inert for oxygen adsorption. Oxygen adsorption on the (111) face damaged by argon ion bombardment was also investigated. The above results were compared with those of early reported work function and oxygen adsorption values. (U.K.)

  18. Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

    International Nuclear Information System (INIS)

    Kuznetsov, G.F.

    2006-01-01

    Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

  19. Energy levels of the single excited states in NaI and Na-like ions

    International Nuclear Information System (INIS)

    El-Sherbini, T.M.; Wahby, A.S.

    1987-08-01

    Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

  20. Study on relations between heavy ions single event upset cross sections and γ accumulated doses

    International Nuclear Information System (INIS)

    He Chaohui; Geng Bin; Wang Yanping; Peng Honglun; Yang Hailiang; Chen Xiaohua; Li Guozheng

    2002-01-01

    Experiments were done under 252 Cf and 60 Co γ source to study the relation between heavy ion Single Event Upset (SEU) cross sections and γ accumulated doses. There was no obvious rule and little influence of γ accumulated doses on SEU cross sections when Static Random Access Memories were in power off mode and static power on mode. In active measuring mode, the SEU cross section increased as the accumulated doses increasing when same data were written in memory cells. If reverse data, such as '55' and 'AA', were written in memory cells during the experiment, the SEU cross sections decreased to the level when memories were not irradiated under 60 Co γ source, even more small. It implied that the influence of γ accumulated doses on SEU cross sections can be set off by this method

  1. X-ray diffraction patterns of single crystals implanted with high-energy light ions

    International Nuclear Information System (INIS)

    Wieteska, K.

    1998-01-01

    X-ray diffraction patterns of silicon and gallium arsenide single crystals implanted with high-energy protons and α-particles were studied. A various models of lattice parameter changes were analysed. The agreement between the simulation and experiment proves that the lattice parameter depth-distribution can be assumed to be proportional to vacancy distribution obtained by Monte-Carlo method and from the Biersack-Ziegler theory. Most of the X-ray experiments were performed using synchrotron source of X-ray radiation in particular in the case of back-reflection and transmission section topographic methods. The new method of direct determination of the implanted ion ranges was proposed using synchrotron radiation back-reflection section topography. A number of new interference phenomena was revealed and explained. These interferences are important in the applications of diffraction theory in studying of the real structure of implanted layers. (author)

  2. The effect of Cu{sup II} ions in L-asparagine single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Ricardo C., E-mail: santana@ufg.br; Gontijo, Henrique O.; Menezes, Arthur F.; Martins, José A.; Carvalho, Jesiel F., E-mail: carvalho@ufg.br

    2016-11-15

    We report the synthesis, crystal growth, and spectroscopic characterization of L-asparagine monohydrate (LAM) single crystals doped with CuII. The crystals were successfully grown by slow cooling from a supersaturated aqueous solution up to size of 16×12×2 mm{sup 3};the effect of copper impurities in the crystals morphology was discussed. Electron Paramagnetic Resonance (EPR) was used to calculate the g and hyperfine coupling (A) tensors of the CuII ions (g{sub 1}=2.044, g{sub 2}=2.105, g{sub 3}=2.383and A{sub 1}≈0, A{sub 2}=35, A{sub 3}=108 Gauss). The EPR spectra for certain orientations of the magnetic field suggest that CuII ions are coordinated to two {sup 14}N atoms. Correlating the EPR and optical absorption results, the crystal field and the Cu{sup II} orbital bond parameters were calculated. The results indicate that the paramagnetic center occupies interstitial rhombic distorted site and the ground orbital state for the unpaired electron is the d(x{sup 2}-y{sup 2}).

  3. Significantly enhanced visible light response in single TiO2 nanowire by nitrogen ion implantation

    Science.gov (United States)

    Wu, Pengcheng; Song, Xianyin; Si, Shuyao; Ke, Zunjian; Cheng, Li; Li, Wenqing; Xiao, Xiangheng; Jiang, Changzhong

    2018-05-01

    The metal-oxide semiconductor TiO2 shows enormous potential in the field of photoelectric detection; however, UV-light absorption only restricts its widespread application. It is considered that nitrogen doping can improve the visible light absorption of TiO2, but the effect of traditional chemical doping is far from being used for visible light detection. Herein, we dramatically broadened the absorption spectrum of the TiO2 nanowire (NW) by nitrogen ion implantation and apply the N-doped single TiO2 NW to visible light detection for the first time. Moreover, this novel strategy effectively modifies the surface states and thus regulates the height of Schottky barriers at the metal/semiconductor interface, which is crucial to realizing high responsivity and a fast response rate. Under the illumination of a laser with a wavelength of 457 nm, our fabricated photodetector exhibits favorable responsivity (8 A W-1) and a short response time (0.5 s). These results indicate that ion implantation is a promising method in exploring the visible light detection of TiO2.

  4. Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

    Science.gov (United States)

    Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu; Nakamura, Takashi; Asai, Hiroyuki

    Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO 4) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li xMnO 2) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li xMnO 2 cell had 1.4 mA h g -1 (per 1 g of active material, current density: 3.77 μA cm -2), and the Li/PMS-LiClO 4/Li xMnO 2 cell had 1.6 mA h g -1 (current density: 75.3 μA cm -2).

  5. Luminescent single-ion magnets from Lanthanoid(III) complexes with monodentate ketone ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kanetomo, Takuya; Ishida, Takayuki, E-mail: takayuki.ishida@uec.ac.jp [Department of Engineering Science, The University of Electro-Communications, Tokyo (Japan)

    2016-02-01

    We synthesized [Ln{sup III}(hfac){sub 3}(H{sub 2}O)(L)] (abbreviated as Ln-L; Ln = Gd, Tb, Eu; L = DTBK (di-t-butyl ketone), BP (benzophenone)), in which the carbonyl oxygen atom was coordinated to the Ln ion center, despite of such bulky substituents. Their crystal structures were determined by means of X-ray diffraction study. Gd-DTBK is completely isomorphous to the di-t-butyl nitroxide derivative and accordingly can be regarded as a model with the ligand spin masked. The ac magnetic susceptibility measurements on Tb-DTBK and -BP showed frequency dependence, characteristic of single-ion magnets. They also displayed photoluminescence in the solid state at room temperature. The quantum yields of the luminescence of Tb-DTBK and -BP (λ{sub ex} = 360 nm) were improved to 57 and 35%, respectively, from that of the starting material [TbI{sup III}(hfac){sub 3}(H{sub 2}O){sub 2}] (28% at λ{sub ex} = 370 nm). Similarly, the quantum yields for Eu-DTBK and -BP were 8 and 15%, respectively, with λ{sub ex} = 400 nm, while that of the starting material [EuI{sup III}(hfac){sub 3}(H{sub 2}O){sub 2}] was 4% at λ{sub ex}=400 nm.

  6. Fabrication of hydrogel-coated single conical nanochannels exhibiting controllable ion rectification characteristics.

    Science.gov (United States)

    Wang, Linlin; Zhang, Huacheng; Yang, Zhe; Zhou, Jianjun; Wen, Liping; Li, Lin; Jiang, Lei

    2015-03-07

    Heterogeneous nanochannel materials that endow new functionalities different to the intrinsic properties of two original nanoporous materials have wide potential applications in nanofluidics, energy conversion, and biosensors. Herein, we report novel, interesting hydrogel-composited nanochannel devices with regulatable ion rectification characteristics. The heterogeneous nanochannel devices were constructed by selectively coating the tip side, base side, or both sides of a single conical nanochannel membrane with thin agar hydrogel layers. The tunable ion current rectification of the nanochannels in the three different coating states was systematically demonstrated by current-voltage (I-V) curves. The asymmetric ionic transport property of the conical nanochannel was further strengthened in the tip-coating state and weakened in the base-coating state, whereas the conical nanochannel showed nearly symmetric ionic transport in the dual-coating state. Repeated experiments presented insight into the good stability and reversibility of the three coating states of the hydrogel-nanochannel-integrated systems. This work, as an example, may provide a new strategy to further design and develop multifunctional gel-nanochannel heterogeneous smart porous nanomaterials.

  7. Origins of low resistivity in Al ion-implanted ZnO bulk single crystals

    Science.gov (United States)

    Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

    2011-06-01

    The origins of low resistivity in Al ion-implanted ZnO bulk single crystals are studied by combining Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), photoluminescence (PL), and Van der Pauw methods. The Al-ion implantation (peak concentration: 2.6 × 1020cm-3) into ZnO is performed using a multiple-step energy. The resistivity decreases from ˜104 Ω cm for un-implanted ZnO to 1.4 × 10-1 Ω cm for as-implanted, and reaches 6.0 × 10-4 Ω cm for samples annealed at 1000 °C. RBS and NRA measurements for as-implanted ZnO suggest the existence of the lattice displacement of Zn (Zni) and O (Oi), respectively. After annealing at 1000 °C, the Zni related defects remain and the Oi related defects disappear. The origin of the low resistivity in the as-implanted sample is attributed to the Zni (˜30 meV [Look et al., Phys. Rev. Lett. 82, 2552 (1999)]). In contrast, the origin of the low resistivity in the sample annealed at 1000 °C is assigned to both of the Zni related defects and the electrically activated Al donor. A new PL emission appears at around 3.32 eV after annealing at 1000 °C, suggesting electrically activated Al donors.

  8. Influence of strong single-ion anisotropy on phase states of 3D and 2D frustrated magnets

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Kosmachev, O.A.; Matunin, D.A.; Gorelikov, G.A.; Klevets, Ph.N.

    2010-01-01

    We investigated the influence of strong single-ion anisotropy, exceeding exchange interaction, and frustrated exchange interaction on spin-wave excitation spectra and phase states using the Hubbard operators' technique, allowing the exact account of single-ion anisotropy. The results show that both the homogeneous phases (ferromagnetic and quadrupolar) and the spatially inhomogeneous phase (spiral structure) are possible in the 3D magnetic crystal. The region of existence of the spiral structure is considerably smaller than that in the analogues system, but with weak single-ion anisotropy. The situation is more complex in the 2D system; another spatially inhomogeneous state (the domain structure) can be realized in addition to the spiral magnetic structure. The phase diagrams for both the 3D and 2D systems were plotted.

  9. Self-supporting film method of silicon single crystal by ion implantation and it`s application

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kazuo; Nakao, Setsuo; Niwa, Hiroaki; Miyagawa, Soji [National Industrial Research Inst. of Nagoya (Japan)

    1996-12-01

    A few {mu}m of thickness of self-supporting film of silicon single crystal was produced by the ion implantation and the selective etching. This materials are distinguished by a uniform film thickness, good controllability, crystallization and the mechanical strength. For applying it to device, the detailed process has to be established, because there are some improved problems such as pinhole and morphology on the surface. This materials are very useful to the basic experiment of the base for epitaxial growth under irradiation of ion beams and the ion beam analysis in the atmosphere. (S.Y.)

  10. Ionization in matrix-assisted laser desorption/ionization: singly charged molecular ions are the lucky survivors.

    Science.gov (United States)

    Karas, M; Glückmann, M; Schäfer, J

    2000-01-01

    A new model for the ionization processes in UV matrix-assisted laser desorption/ionization (MALDI) which accounts for the major phenomena observed is presented and discussed. The model retains elements of earlier approaches, such as photoionization and photochemical reactions, but it redefines these in the light of new working questions, most importantly why only singly charged ions are detected. Based on experimental evidence, the formation of singly and multiply charged clusters by a deficiency/excess of ions and also by photoionization and subsequent photochemical processes is pointed out to be the major ionization processes, which typically occur in parallel. The generation of electrons and their partial loss into the surrounding vacuum and solid, on the one hand, results in a positively charged ion-neutral plume facilitating a high overall ionization yield. On the other hand, these electrons, and also the large excess of protonated matrix ions in the negative ion mode, induce effective ion reneutralization in the plume. These neutralization processes are most effective for the highly charged cluster ions initially formed. Their fragmentation behaviour is evidenced in fast metastable fragmentation characteristics and agrees well with an electron capture dissociation mechanism and the enthalpy transfer upon neutralization forms the rationale for the prominent fragmentation and intense chemical noise accompanying successful MALDI. Within the course of the paper, cross-correlations with other desorption/ionization techniques and with earlier discussions on their mechanisms are drawn. Copyright 2000 John Wiley & Sons, Ltd.

  11. Confined Diffusion Without Fences of a G-Protein-Coupled Receptor as Revealed by Single Particle Tracking

    Science.gov (United States)

    Daumas, Frédéric; Destainville, Nicolas; Millot, Claire; Lopez, André; Dean, David; Salomé, Laurence

    2003-01-01

    Single particle tracking is a powerful tool for probing the organization and dynamics of the plasma membrane constituents. We used this technique to study the μ-opioid receptor belonging to the large family of the G-protein-coupled receptors involved with other partners in a signal transduction pathway. The specific labeling of the receptor coupled to a T7-tag at its N-terminus, stably expressed in fibroblastic cells, was achieved by colloidal gold coupled to a monoclonal anti T7-tag antibody. The lateral movements of the particles were followed by nanovideomicroscopy at 40 ms time resolution during 2 min with a spatial precision of 15 nm. The receptors were found to have either a slow or directed diffusion mode (10%) or a walking confined diffusion mode (90%) composed of a long-term random diffusion and a short-term confined diffusion, and corresponding to a diffusion confined within a domain that itself diffuses. The results indicate that the confinement is due to an effective harmonic potential generated by long-range attraction between the membrane proteins. A simple model for interacting membrane proteins diffusion is proposed that explains the variations with the domain size of the short-term and long-term diffusion coefficients. PMID:12524289

  12. CDW-EIS model for single-electron capture in ion-atom collisions involving multielectronic targets

    International Nuclear Information System (INIS)

    Abufager, P N; MartInez, A E; Rivarola, R D; Fainstein, P D

    2004-01-01

    A generalization of the continuum distorted wave eikonal initial state (CDW-EIS) approximation, for the description of single-electron capture in ion-atom collisions involving multielectronic targets is presented. This approximation is developed within the framework of the independent electron model taking particular care of the representation of the bound and continuum target states. Total cross sections for single-electron capture from the K-shell of He, Ne and Ar noble gases by impact of bare ions are calculated. Present results are compared to previous CDW-EIS ones and to experimental data

  13. A study of V79 cell survival after for proton and carbon ion beams as represented by the parameters of Katz' track structure model

    DEFF Research Database (Denmark)

    Grzanka, Leszek; Waligórski, M. P. R.; Bassler, Niels

    different sets of data obtained for the same cell line and different ions, measured at different laboratories, we have fitted model parameters to a set of carbon-irradiated V79 cells, published by Furusawa et al. (2), and to a set of proton-irradiated V79 cells, published by Wouters et al. (3), separately....... We found that values of model parameters best fitted to the carbon data of Furusawa et al. yielded predictions of V79 survival after proton irradiation which did not match the V79 proton data of Wouters et al. Fitting parameters to both sets combined did not improve the accuracy of model predictions...... carbon irradiation. 1. Katz, R., Track structure in radiobiology and in radiation detection. Nuclear Track Detection 2: 1-28 (1978). 2. Furusawa Y. et al. Inactivation of aerobic and hypoxic cells from three different cell lines by accelerated 3He-, 12C- and 20Ne beams. Radiat Res. 2012 Jan; 177...

  14. Single molecule tracking

    Science.gov (United States)

    Shera, E. Brooks

    1988-01-01

    A detection system is provided for identifying individual particles or molecules having characteristic emission in a flow train of the particles in a flow cell. A position sensitive sensor is located adjacent the flow cell in a position effective to detect the emissions from the particles within the flow cell and to assign spatial and temporal coordinates for the detected emissions. A computer is then enabled to predict spatial and temporal coordinates for the particle in the flow train as a function of a first detected emission. Comparison hardware or software then compares subsequent detected spatial and temporal coordinates with the predicted spatial and temporal coordinates to determine whether subsequently detected emissions originate from a particle in the train of particles. In one embodiment, the particles include fluorescent dyes which are excited to fluoresce a spectrum characteristic of the particular particle. Photones are emitted adjacent at least one microchannel plate sensor to enable spatial and temporal coordinates to be assigned. The effect of comparing detected coordinates with predicted coordinates is to define a moving sample volume which effectively precludes the effects of background emissions.

  15. Irradiation of zinc single crystal with 500 keV singly-charged carbon ions: surface morphology, structure, hardness, and chemical modifications

    Science.gov (United States)

    Waqas Khaliq, M.; Butt, M. Z.; Saleem, Murtaza

    2017-07-01

    Cylindrical specimens of (1 0 4) oriented zinc single crystal (diameter  =  6 mm and length  =  5 mm) were irradiated with 500 keV C+1 ions with the help of a Pelletron accelerator. Six specimens were irradiated in an ultra-high vacuum (~10‒8 Torr) with different ion doses, namely 3.94  ×  1014, 3.24  ×  1015, 5.33  ×  1015, 7.52  ×  1015, 1.06  ×  1016, and 1.30  ×  1016 ions cm-2. A field emission scanning electron microscope (FESEM) was utilized for the morphological study of the irradiated specimens. Formation of nano- and sub-micron size rods, clusters, flower- and fork-like structures, etc, was observed. Surface roughness of the irradiated specimens showed an increasing trend with the ions dose. Energy dispersive x-ray spectroscopy (EDX) helped to determine chemical modifications in the specimens. It was found that carbon content varied in the range 22.86-31.20 wt.% and that oxygen content was almost constant, with an average value of 10.16 wt.%. The balance content was zinc. Structural parameters, i.e. crystallite size and lattice strain, were determined by Williamson-Hall analysis using x-ray diffraction (XRD) patterns of the irradiated specimens. Both crystallite size and lattice strain showed a decreasing trend with the increasing ions dose. A good linear relationship between crystallite size and lattice strain was observed. Surface hardness depicted a decreasing trend with the ions dose and followed an inverse Hall-Petch relation. FTIR spectra of the specimens revealed that absorption bands gradually diminish as the dose of singly-charged carbon ions is increased from 3.94  ×  1014 ions cm-1 to 1.30  ×  1016 ions cm-1. This indicates progressive deterioration of chemical bonds with the increase in ion dose.

  16. WWC Review of the Report "Are Tenure Track Professors Better Teachers?" What Works Clearinghouse Single Study Review

    Science.gov (United States)

    What Works Clearinghouse, 2014

    2014-01-01

    The study reviewed here examined whether taking a course with a tenure track professor versus a non-tenure track professor for first-term freshman-level courses (e.g., introductory economics) had an impact on students' future enrollment and performance in classes in the same subject. Data from 15,662 students who entered Northwestern University,…

  17. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Borràs, S. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Kaufmann, A., E-mail: anton.kaufmann@klzh.ch [Official Food Control Authority, Fehrenstrasse 15, 8032 Zürich (Switzerland); Companyó, R. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain)

    2013-04-15

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed.

  18. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    International Nuclear Information System (INIS)

    Borràs, S.; Kaufmann, A.; Companyó, R.

    2013-01-01

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed

  19. Synchrotron Topographic and Diffractometer Studies of Buried Layered Structures Obtained by Implantation with Swift Heavy Ions in Silicon Single Crystals

    International Nuclear Information System (INIS)

    Wierzchowski, W.; Wieteska, K.; Zymierska, D.; Graeff, W.; Czosnyka, T.; Choinski, J.

    2006-01-01

    A distribution of crystallographic defects and deformation in silicon crystals subjected to deep implantation (20-50 μm) with ions of the energy of a few MeV/amu is studied. Three different buried layered structures (single layer, binary buried structure and triple buried structure) were obtained by implantation of silicon single crystals with 184 MeV argon ions, 29.7 MeV boron ions, and 140 MeV argon ions, each implantation at a fluency of 1x10 14 ions cm -2 . The implanted samples were examined by means of white beam X-ray section and projection topography, monochromatic beam topography and by recording local rocking curves with the beam restricted to 50 x 50 μm 2 . The experiment pointed to a very low level of implantation-induced strain (below 10 -5 ). The white beam Bragg case section experiment revealed a layer producing district black contrast located at a depth of the expected mean ion range. The presence of these buried layered structures in studied silicon crystals strongly affected the fringe pattern caused by curvature of the samples. In case of white beam projection and monochromatic beam topographs the implanted areas were revealed as darker regions with a very tiny grain like structure. One may interpret these results as the effect of considerable heating causing annihilation of point defects and formation of dislocation loops connected with point defect clusters. (author)

  20. Electron impact ionization of B-like ion N2+. Resonance enhancement of the single-channel cross section

    International Nuclear Information System (INIS)

    Li Guohe; Qian Xingzhong; Pan Soufu

    1998-01-01

    The electron impact ionization cross sections of B-like ion N 2+ are calculated in the Coulomb-Born no exchange approximation by using R-matrix method, and the single differential cross section is given. The calculated results exhibit the Rydberg series of resonances. The resonance enhancement of the single-channel cross section is significantly greater than direct ionization cross section. It is agreement with that of Chidichimo