WorldWideScience

Sample records for fast fall-time ion

  1. High-Voltage Power Supply With Fast Rise and Fall Times

    Science.gov (United States)

    Bearden, Douglas B.; Acker, Richard M.; Kapuslka, Robert E.

    2007-01-01

    A special-purpose high-voltage power supply can be electronically switched on and off with fast rise and fall times, respectively. The output potential is programmable from 20 to 1,250 V. An output current of 50 A can be sustained at 1,250 V. The power supply was designed specifically for electronically shuttering a microchannel plate in an x-ray detector that must operate with exposure times as short as 1 ms. The basic design of the power supply is also adaptable to other applications in which there are requirements for rapid slewing of high voltages. The power-supply circuitry (see figure) includes a preregulator, which is used to program the output at 1/30 of the desired output potential. After the desired voltage has been set, the outputs of a pulse width modulator (PWM) are enabled and used to amplify the preregulator output potential by 30. The amplification is achieved by use of two voltage doublers with a transformer that has two primary and two secondary windings. A resistor is used to limit the current by controlling the drive voltage of two field-effect transistors (FETs) during turn-on of the PWM. A pulse transformer is used to turn on four FETs to short-circuit four output capacitors when the outputs of the PWM have been disabled. The most notable aspects of the performance of the power supply are a rise time of only 80 s and a fall time of only 60 s at a load current of 50 A or less. Another notable aspect is that the application of a 0-to-5-V square wave to a shutdown pin of the PWM causes the production of a 0-to-1,250-V square wave at the output terminals.

  2. Fast ion atomic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Berry, H.G.; Young, L.; Goodman, L.S.; Somerville, L.P.; Hardis, J.; Neek, D.

    1984-01-01

    We have set up two collinear fast beam/laser excitation systems, one at the Argonne Dynamitron Accelerator (0.5 to 5.0 MeV beam energy) and another at a small electrostatic accelerator (20 to 130 keV). Our objective is to study fine structure, hyperfine structure and QED effects in ions of a few electrons. Initial projects underway include studies of multi-excited transitions in Li/sup -/ and Li/sup 0/, and transitions to high Rydberg states in H/sup 0/ and He/sup 0/. We have simultaneously excited a sodium jet with a laser at the resonance wavelength (D/sub 1/ or D/sub 2/ lines) and a 1-MeV He/sup +/ beam to produce excitation to autoionizing Na and Na/sup +/ states. The Auger electron spectra are compared to spectra obtained without laser excitation, and indicate strong variations in final state populations. 17 references.

  3. Fast ion loss diagnostic plans for NSTX

    International Nuclear Information System (INIS)

    Darrow, D. S.; Bell, R.; Johnson, R.; Kugel, H.; Wilson, J. R.; Cecil, F. E.; Maingi, R.; Krasilnikov, A.; Alekseyev, A.

    2000-01-01

    The prompt loss of neutral beam ions from the National Spherical Torus Experiment (NSTX) is expected to be between 12% and 42% of the total 5 MW of beam power. There may, in addition, be losses of fast ions arising from high harmonic fast wave (HHFW) heating. Most of the lost ions will strike the HHFW antenna or the neutral beam dump. To measure these losses in the 2000 experimental campaign, thermocouples in the antenna, several infrared camera views, and a Faraday cup lost ion probe will be employed. The probe will measure loss of fast ions with E > 1 keV at three radial locations, giving the scrape-off length of the fast ions

  4. ITER Fast Ion Collective Thomson Scattering

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Larsen, Axel Wright; Meo, Fernando

    2005-01-01

    The EFDA Contract 04-1213 with Risø National Laboratory concerning a detailed integrated design of a Fast Ion Collective Thomson Scattering (CTS) diagnostic for ITER was signed on 31 December 2004. In 2003 the Risø CTS group finished a feasibility study and a conceptual design of an ITER Fast Ion...... Collective Thomson Scattering System (Contract 01.654) [1, 2]. The purpose of the CTS diagnostic is to measure the distribution function of fast ions in the plasma. The feasibility study demonstrated that the only system that can fully meet the ITER measurement requirements for confined fusion alphas is a 60...... GHz system. The study showed that with two powerful microwave sources of this frequency (gyrotron) and two antenna systems, one on the low field side (LFS) and one on the high field side (HFS), it should be possible to resolve the distribution function of fast ions both for perpendicular and parallel...

  5. Fast Quantum Rabi Model with Trapped Ions.

    Science.gov (United States)

    Moya-Cessa, Héctor M

    2016-12-12

    We show how to produce a fast quantum Rabi model with trapped ions. Its importance resides not only in the acceleration of the phenomena that may be achieved with these systems, from quantum gates to the generation of nonclassical states of the vibrational motion of the ion, but also in reducing unwanted effects such as the decay of coherences that may appear in such systems.

  6. Electron spectroscopy with fast heavy ions

    International Nuclear Information System (INIS)

    Schneider, D.

    1983-01-01

    Since about 1970 the spectroscopy of Auger-electrons and characteristic x-rays following energetic ion-atom collisions has received a great deal of attention. An increasing number of accelerators, capable of providing a large number of projectile ion species over a wide range of projectile energies, became available for studying ion-atom collision phenomena. Many charged particles from protons up to heavy ions like uranium can be accelerated to energies ranging over six orders of magnitude. This allows us to study systematically a great variety of effects accompanied by dynamic excitation processes of the atomic shells in either the projectile- or target-atoms. The studies yield fundamental information regarding the excitation mechanism (e.g., Coulomb and quasi-molecular excitation) and allow sensitive tests of atomic structure theories. This information in turn is valuable to other fields in physics like plasma-, astro-, or solid-state (surface) physics. It is a characteristic feature of fast heavy-ion accelerators that they can produce highly stripped ion species which have in turn the capability to highly ionize neutral target atoms or molecules in a single collision. The ionization process, mainly due to the strong electrical fields that are involved, allows us to study few-electron atoms with high atomic numbers Z. High resolution spectroscopy performed with these atoms allows a particularly good test of relativistic and QED effects. The probability of producing these few electron systems is determined by the charge state and the velocity of the projectile ions. In this contribution the possibilities of using electron spectroscopy as a tool to investigate fast ion-atom collisions is discussed and demonstrated with a few examples. 30 references

  7. Fast sodium ion conductivity in supertetrahedral phosphidosilicates.

    Science.gov (United States)

    Johrendt, Dirk; Haffner, Arthur; Hatz, Anna Katharina; Moudrakovski, Igor; Lotsch, Bettina Valeska

    2018-04-03

    Fast sodium ion conductors are key components of sodium-based all-solid-state batteries which hold promise as safe systems for large-scale storage of electrical power. Here, we report the synthesis, crystal structure determination and Na+ ion conductivities of six new sodium ion conductors, the phosphidosilicates Na19Si13P25, Na23Si19P33, Na23Si28P45, Na23Si37P57, LT-NaSi2P3 and HT-NaSi2P3, which are entirely based on earth-abundant elements. The new structures exhibit SiP4 tetrahedra assembling interpenetrating networks of T3 to T5 supertetrahedral clusters which can be hierarchically assigned to sphalerite- or diamond-type structures. 23Na solid-state NMR spectra and geometrical pathway analysis indicate Na+ ion mobility between the supertetrahedral cluster networks. Electrochemical impedance spectroscopy revealed Na+ ion conductivities up to σ (Na+) = 4 ∙ 10-4 Scm-1 with an activation energy of Ea = 0.25 eV in HT-NaSi2P3 at 25 °C. The conductivities increase with the size of the supertetrahedral clusters due to the dilution of Na+ ions as the charge density of the anionic supertetrahedral networks decreases. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Ion beam heating for fast ignition

    International Nuclear Information System (INIS)

    Gus'kov, S.Yu.; Limpouch, J.; Klimo, O.

    2010-01-01

    Complete text of publication follows. The characteristics features of the formation of the spatial distribution of the energy transferred to the plasma from a beam of ions with different initial energies, masses and charges under fast ignition conditions are determined. The motion of the Bragg peak is extended with respect to the spatial distribution of the temperature of the ion-beam-heated medium. The parameters of the ion beams are determined to initiate different regimes of fast ignition of thermonuclear fuel precompressed to a density of 300-500 g/cm 3 - the edge regime, in which the ignition region is formed at the outer boundary of the fuel, and the internal regime, in which the ignition region is formed in central parts of the fuel. The conclusion on the requirements for fast ignition by light and heavy ion beams is presented. It is shown that the edge heating with negative temperature gradient is described by a self-similar solution. Such a temperature distribution is the reason of the fact that the ignited beam energy at the edge heating is larger than the minimal ignition energy by factor 1.65. The temperature Bragg peak may be produced by ion beam heating in the reactor scale targets with pR-parameter larger than 3-4 g/cm 2 . In particular, for central ignition of the targets with pR-parameters in the range of 4-8 g/cm 2 the ion beam energy should be, respectively, from 5 to 7 times larger than the minimal ignition energy. The work by S.Ye. Gus'kov, D.V. Il'in, and V.E. Sherman was supported by the Ministry of Education and Science of the Russian Federation under the program 'Development of the Scientific Potential of High Education for 2009-2010' (project no. 2.1.1/1505) and the Russian Foundation for Basic Research (project no. 08-02-01394 a ). The work by J. Limpouch and O. Klimo was supported by the Czech Ministry of Education (project no. LC528, MSM6840770022).

  9. Fast ions and momentum transport in JET tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Salmi, A.

    2012-07-01

    Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

  10. Scaling of Kinetic Instability Induced Fast Ion Losses in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    E.D. Fredrickson; D. Darrow; S. Medley; J. Menard; H. Park; L. Roquemore; D. Stutman; K. Tritz; S. Kubota; K.C. Lee

    2005-06-24

    During neutral beam injection (NBI) in the National Spherical Torus Experiment (NSTX), a wide variety of fast ion driven instabilities is excited by the large ratio of fast ion velocity to Alfven velocity, together with the relatively high fast ion beta, beta(sub)f. The fast ion instabilities have frequencies ranging from a few kilohertz to the ion cyclotron frequency. The modes can be divided roughly into three categories, starting with Energetic Particle Modes (EPM) in the lowest frequency range (0 to 120 kHz), the Toroidal Alfven Eigenmodes (TAE) in the intermediate frequency range (50 to 200 kHz) and the Compressional and Global Alfven Eigenmodes (CAE and GAE, respectively) from approximately equal to 300 kHz up to the ion cyclotron frequency. Each of these categories of modes exhibits a wide range of behavior, including quasi-continuous oscillation, bursting, chirping and, except for the lower frequency range, turbulence.

  11. Fast Ion Collective Thomson Scattering Diagnostic for ITER

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran

    2008-01-01

    In the era of high power and burning plasma fusion experiments with significant populations of fast particles, the diagnosis of fast ion dynamics becomes an important topic. In ITER, populations of fast ions due to ICRH and NBI, as well as fusion born alphas will carry a significant fraction of t...... of mock-up measurements have brought the design towards a four mirror quasi-optical solution. The development as well as the present design will be presented....

  12. A fast beam-ion instability

    Energy Technology Data Exchange (ETDEWEB)

    Stupakov, G.V. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    The ionization of residual gas by an electron beam in an accelerator generates ions that can resonantly couple to the beam through a wave propagating in the beam-ion system. Results of the study of a beam-ion instability are presented for a multi-bunch train taking into account the decoherence of ion oscillations due to the ion frequency spread and spatial variation of the ion frequency. It is shown that the combination of both effects can substantially reduce the growth rate of the instability. (author)

  13. Fast ion absorption of lower hybrid power in JET

    International Nuclear Information System (INIS)

    Andrade, M.C.R.; Brusati, M.

    1993-01-01

    The first experimental evidence at JET on the interaction of fast minority ions with LH is reported. An increase of approximately 20% on the fast ion energy content was observed in the presence of LH, with an estimated LH absorbed power of approximately 20% for 2 MW of LH power and plasma densities of 2.0 to 2.4 x 10 19 m -3 with central temperatures γ ray and neutron rates also show that absorption of LH waves by the fast minority ions is taking place. FFT analysis confirms a better damping of the wave when the overlap between ICRH and LHCD is maximized. (author)

  14. Study on fast ion loss in HL-2A tokamak

    International Nuclear Information System (INIS)

    Liu Yi; Sun Tengfei; Ji Xiaoquan

    2012-01-01

    Experiments with a high-energy deuterium neutral beam (NB) injection (30 keV, about 0.6 MW) were performed on the HL-2A tokamak. Analysis of neutron decay following the NB 'blip' injection indicates that tangentially injected beam ions are well confined, slowing down classically in the HL-2A. Anomalous losses of beam ions were observed when a beta-induced Alfven acoustic (BAAE) mode was present in the plasma. Such a high energetic particle driven mode led to fast-ion loss, showing a strong influence of the energetic particle driven mode on the fast-ion transport. (authors)

  15. Fast ion collective Thomson scattering diagnostic for ITER: Design elements

    DEFF Research Database (Denmark)

    Tsakadze, Erekle; Bindslev, Henrik; Korsholm, Søren Bang

    2008-01-01

    The proposed fast ion collective Thomson scattering (CTS) diagnostic system for ITER provides the unique capability of measuring the temporally and spatially resolved velocity distribution of the confined fast ions and fusion alpha particles in a burning ITER plasma. The present paper describes t...... in the studies, and new HFS receiver mock-up measurements are presented as well as neutron flux calculations of the influence of the increased slot height....

  16. Glancing-angle scattering of fast ions at crystal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mannami, Michihiko; Narumi, Kazumasa; Katoh, Humiya; Kimura, Kenji [Kyoto Univ. (Japan). Faculty of Engineering

    1997-03-01

    Glancing angle scattering of fast ions from a single crystal surface is a novel technique to study ion-surface interaction. Results of recent studies of ion-surface interaction are reviewed for ions with velocities faster than the Fermi velocity of solid. For the ions with velocities less than the Fermi velocity of target valence electrons the ion-surface interaction shows a new aspect where only the valence electrons of target solid participate in the stopping processes. It will show that the position-dependent stopping power of a surface for these ions governed by the elastic collisions of valence electrons and the ions. A method is proposed from this position-dependent stopping power to derived the electron density distribution averaged over the plane parallel to the surface. (author)

  17. Fast changes of ion distribution function in bow shock

    International Nuclear Information System (INIS)

    Safrankova, J.; Kozak, I.; Nemecek, Z.

    1985-01-01

    The experimental results of Prognoz-8 satellite are reported. In 1981 the basic plasma parameters (ion velocity, density, temperature) were monitored in the solar wind and in the Earth's magnetoshere. Fast variations of the parameters were found. Theoretical interpretation of the data concluded with the observation of a shock wave. The phenomenon was so fast that the statistical significance of the measured histograms was too low for further analysis. (D.Gy.)

  18. Longitudinal dynamics of laser-cooled fast ion beams

    DEFF Research Database (Denmark)

    Weidemüller, M.; Eike, B.; Eisenbarth, U.

    1999-01-01

    We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal-transverse co......We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal....... When applying laser cooling in square-well buckets over long time intervals, hard Coulomb collisions suddenly disappear and the longitudinal temperature drops by about a factor of three. The observed longitudinal behaviour of the beam shows strong resemblance with the transition to an Coulomb...

  19. Linear induction accelerator requirements for ion fast ignition

    Energy Technology Data Exchange (ETDEWEB)

    Logan, G.

    1998-01-26

    Fast ignition (fast heating of DT cores afief compression) reduces driver energy (by 10 X or more) by reducing the implosion velocity and energy for a given fuel compression ratio. For any type of driver that can deliver the ignition energy fast enough, fast ignition increases the target gain compared to targets using fast implosions for central ignition, as long as the energy to heat the core after compression is comparable to or less than the slow compression energy, and as long as the coupling efficiency of the fast ignitor beam to heat the core is comparable to the overall efficiency of compressing the core (in terms of beam energy-to-DT-efficiency). Ion driven fast ignition, compared to laser-driven fast ignition, has the advantage of direct (dE/dx) deposition of beam energy to the DT, eliminating inefficiencies for conversion into hot electrons, and direct ion heating also has a more favorable deposition profile with the Bragg-peak near the end of an ion range chosen to be deep inside a compressed DT core. While Petawatt laser experiments at LLNL have demonstrated adequate light-to-hot-electron conversion efficiency, it is not yet known if light and hot electrons can channel deeply enough to heat a small portion of a IOOOxLD compressed DT core to ignition. On the other hand, lasers with chirped-pulse amplification giving thousand-fold pulse compressions have been demonstrated to produce the short pulses, small focal spots and Petawatt peak powers approaching those required for fast ignition, whereas ion accelerators that can produce sufficient beam quality for similar compression ratios and focal spot sizes of ion bunches have not yet been demonstrated, where an imposed coherent velocity tilt plays the analogous role for beam compression as does frequency chirp with lasers. Accordingly, it is the driver technology, not the target coupling physics, that poses the main challenge to ion-driven fast ignition. As the mainline HIF program is concentrating on

  20. Fast ion-atom and ion-molecule collisions

    CERN Document Server

    2013-01-01

    The principal goal of this book is to provide state-of-the art coverage of the non-relativistic three- and four-body theories at intermediate and high energy ion-atom and ion-molecule collisions. The focus is on the most frequently studied processes: electron capture, ionization, transfer excitation and transfer ionization. The content is suitable both for graduate students and experienced researchers. For these collisions, the literature has seen enormous renewal of activity in the development and applications of quantum-mechanical theories. This subject is of relevance in several branches of science and technology, like accelerator-based physics, the search for new sources of energy and high temperature fusion of light ions. Other important applications are in life sciences via medicine, where high-energy ion beams are used in radiotherapy for which a number of storage ring accelerators are in full operation, under construction or planned to be built worldwide. Therefore, it is necessary to review this fiel...

  1. Charge exchange spectroscopy as a fast ion diagnostic on TEXTOR

    DEFF Research Database (Denmark)

    Delabie, E.; Jaspers, R.J.E.; von Hellermann, M.G.

    2008-01-01

    An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam...

  2. Fast ion diagnostics for the C-2 experiment

    Science.gov (United States)

    Korepanov, Sergey; Clary, Ryan; Smirnov, Artem; Dettrick, Sean; Murakhtin, Sergey; Polosatkin, Sergey

    2011-10-01

    One of the goals of the C-2 experiment is to explore FRC sustainment and current drive from neutral beam injection. Studies of the relaxation and confinement of hot anisotropic ions created by the neutral beams are considered to be key elements of the experimental research program. To realize this approach a set of diagnostics for the measurement of local parameters of fast ions has been developed. In particular, this set includes diagnostics to measure the local energy (neutral particle analyzer, LiNb3-based pyro-bolometers) and the angular distribution function (silicone-based neutral particle bolometers). For numerical studies of fast ion dynamics a Monte Carlo code has been elaborated.

  3. Fast ion distribution in the presence of flow

    Science.gov (United States)

    Davidovits, Seth; Fisch, Nathaniel

    2014-10-01

    Experiments and simulations in multiple ICF related configurations have observed signs of bulk flow near stagnation. These configurations include both laser driven implosions such as at the NIF, as well as Z-Pinches. We investigate the possibilities for enhancement or depletion of fast ion tails in simplified flow models, with an eye towards applicability to ICF experiments. Small effects on the tail populations may substantially affect fusion output, as the fast ions in these tails have much larger fusion cross sections than thermal ions and make up the majority of fusion production for typical ICF temperatures. While in collisional plasma the bulk of the distribution function is driven toward Maxwellian in a few collision times, the high velocity tails can take much longer to form. Furthermore, the long mean free paths of the fast ions means they may sample differing regions of flow, while thermal particles only sample the local flow. This work was supported by DOE through Contracts DE-AC02-09CH1-1466 and 67350-9960 (Prime # DOE DE-NA0001836). Seth Davidovits would like to acknowledge support by the DOE-CSGF program under Grant DE-FG02-97ER25308.

  4. FIFPC, a fast ion Fokker--Planck code

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, R.H.; Callen, J.D.; Rome, J.A.; Smith, J.

    1976-07-01

    A computer code is described which solves the Fokker--Planck equation for the velocity space distribution of fast ions injected into a tokamak plasma. The numerical techniques are described and use of the code is outlined. The program is written in FORTRAN IV and is modularized in order to provide greater flexibility to the user. A program listing is provided and the results of sample cases are presented.

  5. Electrical studies on silver based fast ion conducting glassy materials

    International Nuclear Information System (INIS)

    Rao, B. Appa; Kumar, E. Ramesh; Kumari, K. Rajani; Bhikshamaiah, G.

    2014-01-01

    Among all the available fast ion conductors, silver based glasses exhibit high conductivity. Further, glasses containing silver iodide enhances fast ion conducting behavior at room temperature. Glasses of various compositions of silver based fast ion conductors in the AgI−Ag 2 O−[(1−x)B 2 O 3 −xTeO 2 ] (x=0 to1 mol% in steps of 0.2) glassy system have been prepared by melt quenching method. The glassy nature of the compounds has been confirmed by X-ray diffraction. The electrical conductivity (AC) measurements have been carried out in the frequency range of 1 KHz–3MHz by Impedance Analyzer in the temperature range 303–423K. The DC conductivity measurements were also carried out in the temperature range 300–523K. From both AC and DC conductivity studies, it is found that the conductivity increases and activation energy decreases with increasing the concentration of TeO 2 as well as with temperature. The conductivity of the present glass system is found to be of the order of 10 −2 S/cm at room temperature. The ionic transport number of these glasses is found to be 0.999 indicating that these glasses can be used as electrolyte in batteries

  6. Dynamics of fast ions during sawtooth oscillations in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Salewski, Mirko; Bindslev, Henrik

    2011-01-01

    Experimental investigations of sawteeth interaction with fast ions measured by collective Thomson scattering on TEXTOR are presented. Time-resolved measurements of localized 1D fast-ion distribution functions allow us to study fast-ion dynamics during several sawtooth cycles. Sawtooth oscillation...

  7. Methods to determine fast-ion distribution functions from multi-diagnostic measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko

    Understanding the behaviour of fast ions in a fusion plasma is very important, since the fusion-born alpha particles are expected to be the main source of heating in a fusion power plant. Preferably, the entire fast-ion velocity-space distribution function would be measured. However, no fast-ion ...

  8. Progress and prospects of ion-driven fast ignition

    International Nuclear Information System (INIS)

    Fernandez, Juan C.; Albright, Brian J.; Flippo, Kirk A.; Gautier, D. Cort; Hegelich, Bjoern M.; Schmitt, Mark J.; Yin Lin; Honrubia, J.J.; Temporal, M.

    2009-01-01

    Fusion fast ignition (FI) initiated by laser-driven ion beams is a promising concept examined in this paper. FI based on a beam of quasi-monoenergetic ions (protons or heavier ions) has the advantage of a more localized energy deposition, which minimizes the required total beam energy, bringing it close to the ∼10 kJ minimum required for fuel densities ∼500 g cm -3 . High-current, laser-driven ion beams are most promising for this purpose. Because they are born neutralized in picosecond timescales, these beams may deliver the power density required to ignite the compressed DT fuel, ∼10 kJ/10 ps into a spot 20 μm in diameter. Our modelling of ion-based FI include high fusion gain targets and a proof of principle experiment. That modelling indicates the concept is feasible, and provides confirmation of our understanding of the operative physics, a firmer foundation for the requirements, and a better understanding of the optimization trade space. An important benefit of the scheme is that such a high-energy, quasi-monoenergetic ignitor beam could be generated far from the capsule (≥1 cm away), eliminating the need for a reentrant cone in the capsule to protect the ion-generation laser target, a tremendous practical benefit. This paper summarizes the ion-based FI concept, the integrated ion-driven FI modelling, the requirements on the ignitor beam derived from that modelling, and the progress in developing a suitable laser-driven ignitor ion beam.

  9. Longitudinal dynamics of laser-cooled fast ion beams

    DEFF Research Database (Denmark)

    Weidemüller, M.; Eike, B.; Eisenbarth, U.

    1999-01-01

    -transverse coupling mechanisms. Laser cooling in novel bunch forms consisting of square-well buckets leads to longitudinally space-charge dominated beams. The observed longitudinal ion density distributions can be well described by a self-consistent mean-field model based on a thermodynamic Debye-Huckel approach......We present recent results of our experiments on laser cooling of fast stored ion beams at the Heidelberg Test Storage Ring. The longitudinal motion of the ions is directly cooled by the light pressure force, whereas efficient transverse cooling is obtained indirectly by longitudinal....... When applying laser cooling in square-well buckets over long time intervals, hard Coulomb collisions suddenly disappear and the longitudinal temperature drops by about a factor of three. The observed longitudinal behaviour of the beam shows strong resemblance with the transition to an Coulomb...

  10. Physics in the fast lane: rotors, fast ions and mobile fermions

    International Nuclear Information System (INIS)

    Price, D.L.; Saboungi, M.-L.

    1996-09-01

    Dynamic disorder in the high-temperature solid phases of the Zintl compounds CsPb and NaSn is characterized by. fast orientational motions of the polyanions and coupled motions of the cations Melting is characterized by slow translational motions of the centers of mass of the polyanions. The dynamic behavior of the ions is associated with dramatic increases in electrical conductivity characteristic of the behavior expected of a mixed conductor

  11. Measurements of Prompt and MHD-Induced Fast Ion Loss from National Spherical Torus Experiment Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    D.S. Darrow; S.S. Medley; A.L. Roquemore; W.W. Heidbrink; A. Alekseyev; F.E. Cecil; J. Egedal; V.Ya. Goloborod' ko; N.N. Gorelenkov; M. Isobe; S. Kaye; M. Miah; F. Paoletti; M.H. Redi; S.N. Reznik; A. Rosenberg; R. White; D. Wyatt; V.A. Yavorskij

    2002-10-15

    A range of effects may make fast ion confinement in spherical tokamaks worse than in conventional aspect ratio tokamaks. Data from neutron detectors, a neutral particle analyzer, and a fast ion loss diagnostic on the National Spherical Torus Experiment (NSTX) indicate that neutral beam ion confinement is consistent with classical expectations in quiescent plasmas, within the {approx}25% errors of measurement. However, fast ion confinement in NSTX is frequently affected by magnetohydrodynamic (MHD) activity, and the effect of MHD can be quite strong.

  12. Ionization of uracil in collisions with fast bare ions

    Science.gov (United States)

    Tribedi, L. C.; Agnihotri, A. N.; Galassi, M. E.; Rivarola, R. D.; Champion, C.

    2012-11-01

    We study the atomic collisions with large molecules and simple atoms. The ionization and fragmentation spectra are investigated for uracil, a RNA base molecule, under the impact of fast bare C, O and F-ions. The experiments are conducted using a recoil-ion time-of-flight spectrometer. The energy dependence of the total ionization cross sections (TCS) and fragmentation yields are measured for MeV/u energies. In addition, the angular distribution of the electron double differential cross sections (DDCS) are also shown in some cases. The total cross sections of ionization and also the DDCS data are compared with the CDW-EIS calculations. The qualitative agreement is good but, in general, the theory tends to overestimate the data by a factor of 2.2. The angular distribution of electrons clearly indicates a good qualitative agreement except for the lowest energy electrons.

  13. Collisionally induced stochastic dynamics of fast ions in solids

    International Nuclear Information System (INIS)

    Burgdoerfer, J.

    1989-01-01

    Recent developments in the theory of excited state formation in collisions of fast highly charged ions with solids are reviewed. We discuss a classical transport theory employing Monte-Carlo sampling of solutions of a microscopic Langevin equation. Dynamical screening by the dielectric medium as well as multiple collisions are incorporated through the drift and stochastic forces in the Langevin equation. The close relationship between the extrinsically stochastic dynamics described by the Langevin and the intrinsic stochasticity in chaotic nonlinear dynamical systems is stressed. Comparison with experimental data and possible modification by quantum corrections are discussed. 49 refs., 11 figs

  14. Transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  15. THE FREE-FALL TIME OF FINITE SHEETS AND FILAMENTS

    International Nuclear Information System (INIS)

    Toalá, Jesús A.; Vázquez-Semadeni, Enrique; Gómez, Gilberto C.

    2012-01-01

    Molecular clouds often exhibit filamentary or sheet-like shapes. We compute the free-fall time (τ ff ) for finite, uniform, self-gravitating circular sheets and filamentary clouds of small but finite thickness, so that their volume density ρ can still be defined. We find that, for thin sheets, the free-fall time is larger than that of a uniform sphere with the same volume density by a factor proportional to √A, where the aspect ratio A is given by A = R/h, R being the sheet's radius and h is its thickness. For filamentary clouds, the aspect ratio is defined as A=L/R, where L is the filament's half-length and R is its (small) radius, and the modification factor is more complicated, although in the limit of large A it again reduces to nearly √A. We propose that our result for filamentary shapes naturally explains the ubiquitous configuration of clumps fed by filaments observed in the densest structures of molecular clouds. Also, the longer free-fall times for non-spherical geometries in general may contribute toward partially alleviating the 'star formation conundrum', namely, the star formation rate in the Galaxy appears to be proceeding in a timescale much larger than the total molecular mass in the Galaxy divided by its typical free-fall time. If molecular clouds are in general formed by thin sheets and long filaments, then their relevant free-fall time may have been systematically underestimated, possibly by factors of up to one order of magnitude.

  16. The role of fast electrons for the performance characteristics of hydrogen ion sources

    OpenAIRE

    Fukumasa, Osamu; Saeki, Setsuo

    1984-01-01

    The influence of fast primary electrons on the ion species ratios in a hydrogen plasma is discussed numerically. The optimum condition for plasma production with high proton ratio is to eliminate the presence of fast electrons, whereas the production of H^- ions is enhanced anomalously by the presence of fast electrons.

  17. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Bindslev, H.; Nielsen, S.K.; Porte, L.

    2006-01-01

    and ion cyclotron resonance heating. The temporal behavior of the spatially resolved fast-ion velocity distribution is inferred from the received scattered radiation. The fast-ion dynamics at sawteeth and the slowdown after switch off of auxiliary heating is resolved in time. The latter is shown...

  18. Elastic wave from fast heavy ion irradiation on solids

    CERN Document Server

    Kambara, T; Kanai, Y; Kojima, T M; Nanai, Y; Yoneda, A; Yamazaki, Y

    2002-01-01

    To study the time-dependent mechanical effects of fast heavy ion irradiations, we have irradiated various solids by a short-bunch beam of 95 MeV/u Ar ions and observed elastic waves generated in the bulk. The irradiated targets were square-shaped plates of poly-crystals of metals (Al and Cu), invar alloy, ceramic (Al sub 2 O sub 3), fused silica (SiO sub 2) and single crystals of KC1 and LiF with a thickness of 10 mm. The beam was incident perpendicular to the surface and all ions were stopped in the target. Two piezo-electric ultrasonic sensors were attached to the surface of the target and detected the elastic waves. The elastic waveforms as well as the time structure and intensity of the beam bunch were recorded for each shot of a beam bunch. The sensor placed opposite to the beam spot recorded a clear waveform of the longitudinal wave across the material, except for the invar and fused silica targets. From its propagation time along with the sound velocity and the thickness of the target, the depth of the...

  19. Fast ion dynamics in ASDEX upgrade and TEXTOR measured by collective Thomson scattering

    International Nuclear Information System (INIS)

    Moseev, D.

    2011-11-01

    Fast ions are an essential ingredient in burning nuclear fusion plasmas: they are responsible for heating the bulk plasma, carry a significant amount of plasma current and moreover interact with various magnetohydrodynamic (MHD) instabilities. The collective Thomson scattering (CTS) diagnostic is sensitive to the projection of fast ion velocity distribution function. This thesis is mainly devoted to investigations of fast ion physics in tokamak plasmas by means of CTS. (Author)

  20. Fast ion dynamics in ASDEX upgrade and TEXTOR measured by collective Thomson scattering

    Energy Technology Data Exchange (ETDEWEB)

    Moseev, D.

    2011-11-15

    Fast ions are an essential ingredient in burning nuclear fusion plasmas: they are responsible for heating the bulk plasma, carry a significant amount of plasma current and moreover interact with various magnetohydrodynamic (MHD) instabilities. The collective Thomson scattering (CTS) diagnostic is sensitive to the projection of fast ion velocity distribution function. This thesis is mainly devoted to investigations of fast ion physics in tokamak plasmas by means of CTS. (Author)

  1. Modelling of advanced three-ion ICRF heating and fast ion generation scheme for tokamaks and stellarators

    Science.gov (United States)

    Faustin, J. M.; Graves, J. P.; Cooper, W. A.; Lanthaler, S.; Villard, L.; Pfefferlé, D.; Geiger, J.; Kazakov, Ye O.; Van Eester, D.

    2017-08-01

    Absorption of ion-cyclotron range of frequencies waves at the fundamental resonance is an efficient source of plasma heating and fast ion generation in tokamaks and stellarators. This heating method is planned to be exploited as a fast ion source in the Wendelstein 7-X stellarator. The work presented here assesses the possibility of using the newly developed three-ion species scheme (Kazakov et al (2015) Nucl. Fusion 55 032001) in tokamak and stellarator plasmas, which could offer the capability of generating more energetic ions than the traditional minority heating scheme with moderate input power. Using the SCENIC code, it is found that fast ions in the MeV range of energy can be produced in JET-like plasmas. The RF-induced particle pinch is seen to strongly impact the fast ion pressure profile in particular. Our results show that in typical high-density W7-X plasmas, the three-ion species scheme generates more energetic ions than the more traditional minority heating scheme, which makes three-ion scenario promising for fast-ion confinement studies in W7-X.

  2. Analysis methods for fast impurity ion dynamics data

    International Nuclear Information System (INIS)

    Den Hartog, D.J.; Almagri, A.F.; Prager, S.C.; Fonck, R.J.

    1994-08-01

    A high resolution spectrometer has been developed and used on the MST reversed-field pinch (RFP) to measure passively impurity ion temperatures and flow velocities with 10 μs temporal resolution. Such measurements of MHD-scale fluctuations are particularly relevant in the RFP because the flow velocity fluctuation induced transport of current (the ''MHD dynamo'') may produce the magnetic field reversal characteristic of an RFP. This instrument will also be used to measure rapid changes in the equilibrium flow velocity, such as occur during locking and H-mode transition. The precision of measurements made to date is <0.6 km/s. The authors are developing accurate analysis techniques appropriate to the reduction of this fast ion dynamics data. Moment analysis and curve-fitting routines have been evaluated for noise sensitivity and robustness. Also presented is an analysis method which correctly separates the flux-surface average of the correlated fluctuations in u and B from the fluctuations due to rigid shifts of the plasma column

  3. Fast quantum logic gates with trapped-ion qubits

    Science.gov (United States)

    Schäfer, V. M.; Ballance, C. J.; Thirumalai, K.; Stephenson, L. J.; Ballance, T. G.; Steane, A. M.; Lucas, D. M.

    2018-03-01

    Quantum bits (qubits) based on individual trapped atomic ions are a promising technology for building a quantum computer. The elementary operations necessary to do so have been achieved with the required precision for some error-correction schemes. However, the essential two-qubit logic gate that is used to generate quantum entanglement has hitherto always been performed in an adiabatic regime (in which the gate is slow compared with the characteristic motional frequencies of the ions in the trap), resulting in logic speeds of the order of 10 kilohertz. There have been numerous proposals of methods for performing gates faster than this natural ‘speed limit’ of the trap. Here we implement one such method, which uses amplitude-shaped laser pulses to drive the motion of the ions along trajectories designed so that the gate operation is insensitive to the optical phase of the pulses. This enables fast (megahertz-rate) quantum logic that is robust to fluctuations in the optical phase, which would otherwise be an important source of experimental error. We demonstrate entanglement generation for gate times as short as 480 nanoseconds—less than a single oscillation period of an ion in the trap and eight orders of magnitude shorter than the memory coherence time measured in similar calcium-43 hyperfine qubits. The power of the method is most evident at intermediate timescales, at which it yields a gate error more than ten times lower than can be attained using conventional techniques; for example, we achieve a 1.6-microsecond-duration gate with a fidelity of 99.8 per cent. Faster and higher-fidelity gates are possible at the cost of greater laser intensity. The method requires only a single amplitude-shaped pulse and one pair of beams derived from a continuous-wave laser. It offers the prospect of combining the unrivalled coherence properties, operation fidelities and optical connectivity of trapped-ion qubits with the submicrosecond logic speeds that are usually

  4. Temporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Bindslev, Henrik; Porte, L.

    2008-01-01

    Fast ions created in the fusion processes will provide up to 70% of the heating in ITER. To optimize heating and current drive in magnetically confined plasmas insight into fast-ion dynamics is important. First measurements of such dynamics by collective Thomson scattering (CTS) were recently rep...

  5. Combination of fast-ion diagnostics in velocity-space tomographies

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Nielsen, Stefan Kragh

    2013-01-01

    Fast-ion Dα (FIDA) and collective Thomson scattering (CTS) diagnostics provide indirect measurements of fast-ion velocity distribution functions in magnetically confined plasmas. Here we present the first prescription for velocity-space tomographic inversion of CTS and FIDA measurements that can ...

  6. Fast-ion transport and neutral beam current drive in ASDEX upgrade

    DEFF Research Database (Denmark)

    Geiger, B.; Weiland, M.; Jacobsen, Asger Schou

    2015-01-01

    The neutral beam current drive efficiency has been investigated in the ASDEX Upgrade tokamak by replacing on-axis neutral beams with tangential off-axis beams. A clear modification of the radial fast-ion profiles is observed with a fast-ion D-alpha diagnostic that measures centrally peaked profiles...

  7. Velocity-space tomography of the fast-ion distribution function

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko; Geiger, Benedikt

    2013-01-01

    Fast ions play an important role in heating the plasma in a magnetic confinement fusion device. Fast-ion Dα(FIDA) spectroscopy diagnoses fast ions in small measurement volumes. Spectra measured by a FIDA diagnostic can be related to the 2D fast-ion velocity distribution function. A single FIDA view...... probes certain regions in velocity-space, determined by the geometry of the set-up. Exploiting this, the fast-ion distribution function can be inferred using a velocity-space tomography method. This poster contains a tomography calculated from measured spectra from three different FIDA views at ASDEX...... Upgrade. The quality of the tomography improves with the number of FIDA views simultaneously measuring the same volume. To investigate the potential benefits of including additional views (up to 18), tomographies are inferred from synthetic spectra calculated from a simulated distribution function...

  8. Fast optimization and dose calculation in scanned ion beam therapy

    International Nuclear Information System (INIS)

    Hild, S.; Graeff, C.; Trautmann, J.; Kraemer, M.; Zink, K.; Durante, M.; Bert, C.

    2014-01-01

    Purpose: Particle therapy (PT) has advantages over photon irradiation on static tumors. An increased biological effectiveness and active target conformal dose shaping are strong arguments for PT. However, the sensitivity to changes of internal geometry complicates the use of PT for moving organs. In case of interfractionally moving objects adaptive radiotherapy (ART) concepts known from intensity modulated radiotherapy (IMRT) can be adopted for PT treatments. One ART strategy is to optimize a new treatment plan based on daily image data directly before a radiation fraction is delivered [treatment replanning (TRP)]. Optimizing treatment plans for PT using a scanned beam is a time consuming problem especially for particles other than protons where the biological effective dose has to be calculated. For the purpose of TRP, fast optimization and fast dose calculation have been implemented into the GSI in-house treatment planning system (TPS) TRiP98. Methods: This work reports about the outcome of a code analysis that resulted in optimization of the calculation processes as well as implementation of routines supporting parallel execution of the code. To benchmark the new features, the calculation time for therapy treatment planning has been studied. Results: Compared to the original version of the TPS, calculation times for treatment planning (optimization and dose calculation) have been improved by a factor of 10 with code optimization. The parallelization of the TPS resulted in a speedup factor of 12 and 5.5 for the original version and the code optimized version, respectively. Hence the total speedup of the new implementation of the authors' TPS yielded speedup factors up to 55. Conclusions: The improved TPS is capable of completing treatment planning for ion beam therapy of a prostate irradiation considering organs at risk in this has been overseen in the review process. Also see below 6 min

  9. Desorption of organic molecules with fast incident atomic and polyatomic ions

    International Nuclear Information System (INIS)

    Hunt, J.E.; Salehpour, M.; Fishel, D.L.

    1989-01-01

    In 1974, Macfarlane and coworkers introduced a new mass spectrometric technique based on desorption-ionization of sample molecules from solid targets by the impact of fast heavy ions (fission fragments) from 252 Cf. The process of ion-induced desorption of molecular ions from surfaces is not yet fully understood, although a large amount of experimental data related to the mechanism has been published. This paper concerns the use of fast incident polyatomic ions to induce desorption of secondary molecular ions of valine and chlorophyll from surfaces. Polyatomic ions are unique in that they are a collection of temporally and spatially correlated atoms. The main finding in this study is that incident polyatomic ions produce drastic enhancements in the secondary ion yields over atomic ions. Also, two types of nonlinear effects in desorption have been observed and will be discussed

  10. Measurements of the fast ion distribution during neutral beam injection and ion cyclotron heating in ATF [Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Wade, M.R.; Kwon, M.; Thomas, C.E.; Colchin, R.J.; England, A.C.; Gossett, J.M.; Horton, L.D.; Isler, R.C.; Lyon, J.F.; Rasmussen, D.A.; Rayburn, T.M.; Shepard, T.D.; Bell, G.L.; Fowler, R.H.; Morris, R.N.

    1990-01-01

    A neutral particle analyzer (NPA) with horizontal and vertical scanning capability has been used to make initial measurements of the fast ion distribution during neutral beam injection (NBI) and ion cyclotron heating (ICH) on the Advanced Toroidal Facility (ATF). These measurements are presented and compared with the results of modeling codes that predict the analyzer signals during these heating processes. 6 refs., 5 figs

  11. Fast-ion transport studies using FIDA spectroscopy at the ASDEX Upgrade tokamak

    International Nuclear Information System (INIS)

    Geiger, Benedikt

    2013-01-01

    A good confinement of fast-ions, i.e. ions with energies above the thermal energy, is essential for the success of fusion devices as it determines, amongst others, the plasma performance and the heating and current drive efficiencies. In case of a turbulent or magneto-hydrodynamic (MHD) active background plasma, various mechanisms have to be considered in order to estimate the spatial distribution of the fast-ions: the slowing down and radial diffusion by Coulomb collisions on electrons and ions, the effect of potential fluctuations and the effect of perturbations of the magnetic field structure. These can lead to a broadening of the fast-ion distribution function which is not yet completely understood. At the fusion experiment ASDEX Upgrade, the fast-ions are generated by heating sources such as neutral beam injection (NBI). Their transport properties can be studied by a fast-ion D-alpha (FIDA) spectroscopy diagnostic which has been built in the framework of this thesis. Through charge exchange reactions with neutrals, fast-ions can receive a bound electron and emit Balmer alpha line radiation. This so-called FIDA radiation can be measured with large Doppler shifts and is localized along the NBI path where a high density of neutrals is present. The FIDA diagnostic uses radially distributed lines of sight that intersect, in the horizontal and in the vertical plane, the path of a 2.5 MW NBI heating source. Thereby different parts of the fast-ion phase space above 25 keV can be analyzed. To interpret the FIDA radiation quantitatively, a forward modelling code has been implemented, tested and further developed. The code calculates, based on theoretical fast-ion distribution functions, synthetic FIDA spectra that can be compared to the measurement. In MHD-quiescent plasmas, the possible effect of turbulence on the fast-ion transport has been investigated with the FIDA diagnostic. The measurements obtained under different experimental conditions, such as during on- and

  12. Improved Collective Thomson Scattering measurements of fast ions at ASDEX Upgrade

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Nielsen, Stefan Kragh; Stejner Pedersen, Morten

    2014-01-01

    Scattering (CTS) is well suited for reactor conditions and offers such an opportunity by providing measurements of the confined fast-ion distribution function resolved in space, time and 1D velocity space. We currently operate a CTS system at ASDEX Upgrade using a gyrotron which generates probing radiation......Understanding the behaviour of the confined fast ions is important in both current and future fusion experiments. These ions play a key role in heating the plasma and will be crucial for achieving conditions for burning plasma in next-step fusion devices. Microwave-based Collective Thomson...... at 105 GHz. A new setup using two independent receiver systems has enabled improved subtraction of the background signal, and hence the first accurate characterization of fast-ion properties. Here we review this new dual-receiver CTS setup and present results on fast-ion measurements based...

  13. First absolute measurements of fast-ion losses in the ASDEX Upgrade tokamak

    Science.gov (United States)

    Rodriguez-Ramos, M.; Garcia-Munoz, M.; Jimenez-Ramos, M. C.; Garcia Lopez, J.; Galdon-Quiroga, J.; Sanchis-Sanchez, L.; Ayllon-Guerola, J.; Faitsch, M.; Gonzalez-Martin, J.; Hermann, A.; de Marne, P.; Rivero-Rodriguez, J. F.; Sieglin, B.; Snicker, A.; the ASDEX Upgrade Team

    2017-10-01

    A new diagnostic technique that allows to obtain absolute fluxes of fast-ion losses measured with absolutely calibrated scintillator based fast-ion loss detectors (FILD) is presented here. First absolute fluxes of fast-ion losses have been obtained in the ASDEX Upgrade tokamak. An instrument function that includes the scintillator efficiency, collimator geometry, optical transmission and camera efficiency has been constructed. The scintillator response to deuterium ions in the relevant energy range of fast-ions has been characterized using a tandem accelerator. Absolute flux of neutral beam injection (NBI) prompt losses has been obtained in magnetohydrodynamic quiescent plasmas. The temporal evolution of the heat load measured with FILD follows that measured at the FILD entrance obtained with an Infra-Red camera looking at the FILD detector head. ASCOT simulations are in good agreement with the absolute heat load of NBI prompt losses measured with FILD.

  14. Second harmonic ion cylotron resonance heating by the fast magnetosonic wave on the PLT tokamak

    International Nuclear Information System (INIS)

    Thompson, H.R. Jr.

    1984-01-01

    Second harmonic ion cyclotron resonance heating by the fast magnetosonic wave, and the propagation of the fast wave from the fundamental of the ion cyclotron frequency to its second harmonic was investigated in a hydrogen plasma on the PLT tokamak. The theory of fast magnetosonic wave propagation was extended to include the effects of density gradients, plasma current, and impurity ion species. The damping of the fast wave at the second harmonic is calculated, where the theory has been extended to include the full radial dependence of the fast wave fields. Power deposition profiles and eigenmode Q's are calculated using this theory. The effects of the interaction between the ion Bernstein wave and the fast magnetosonic wave are calculated, and enhanced fast wave damping is predicted. The antenna loading is calculated including the effects of overlap of the fast wave eigenmodes. During the second harmonic heating experiments, the antenna loading was characterized as a function of the plasma parameters, and efficient coupling of the RF power to the plasma at high density was observed. At very low densities, fast wave eigenmodes were identified on PLT, and their Q's are measured. Eigenmodes with different toroidal directions of propagation were observed to exhibit large splitting in density due to the plasma current. Efficient bulk heating, with centrally peaked profiles, is observed at the second harmonic, and a tail, which decreases monotonically with energy, is observed on the ion distribution

  15. 'Beam-emission spectroscopy' diagnostics also measure edge fast-ion light

    International Nuclear Information System (INIS)

    Heidbrink, W W; Bortolon, A; McKee, G R; Smith, D R

    2011-01-01

    Beam-emission spectroscopy (BES) diagnostics normally detect fluctuations in the light emitted by an injected neutral beam. Under some circumstances, however, light from fast ions that charge exchange in the high neutral-density region at the edge of the plasma make appreciable contributions to the BES signals. This 'passive' fast-ion D α (FIDA) light appears in BES signals from both the DIII-D tokamak and the National Spherical Torus Experiment (NSTX). One type of passive FIDA light is associated with classical orbits that traverse the edge. Another type is caused by instabilities that expel fast ions from the core; this light can complicate measurement of the instability eigenfunction.

  16. Fast-ion transport in the presence of magnetic reconnection induced by sawtooth oscillations in ASDEX Upgrade

    NARCIS (Netherlands)

    Geiger, B.; M. García-Muñoz,; Dux, R.; Ryter, F.; Tardini, G.; Orte, L. B.; Classen, I.G.J.; Fable, E.; Fischer, R.; Igochine, V.; McDermott, R. M.

    2014-01-01

    The transport of beam-generated fast ions has been investigated experimentally at the ASDEX Upgrade tokamak in the presence of sawtooth crashes. After sawtooth crashes, phase space resolved fast-ion D-alpha measurements show a significant reduction of the central fast-ion density-more than

  17. Dynamics of fast liner with several sorts of ions

    International Nuclear Information System (INIS)

    Gordeev, A.V.

    1987-01-01

    On the basis of hydrodynamic equations describing plasma dynamics with two sorts of ions gaseous linear compression under effect of magnetic field at H 2 >>8πp is considered. It is shown that for a liner with two sorts of ions there is a density range below some critical one, when skin penetration of the magnetic field into plasma is defined by ion-ion collisions

  18. Experimental Comparison of Fast Wave Absorption on Fast Ions at Fourth and Sixth Harmonics

    Science.gov (United States)

    Pinsker, P. I.; Petty, C. C.; Heidbrink, W. W.; Baity, F. W.; Porkolab, M.

    2007-11-01

    In recent DIII-D experiments, we have compared the absorption of fast waves (FWs) on injected deuterium beams at the fourth and sixth deuterium cyclotron harmonics. Direct electron absorption also plays an important part in the core absorption. Up to 2 MW of FW power at 90 MHz is compared with a similar level of 60 MHz power in low-density L-mode discharges at 2 T with 1--2 MW of deuterium beam injection at 80 keV. Changes in the neutron rate and in the central sawtooth behavior are correlated with the observed acceleration of the beam ions by the rf as measured by the Dα charge exchange recombination diagnostic. Results obtained with hydrogen beams in which second and third harmonic absorption at 60 MHz and 90 MHz are compared will be presented. Lower global absorption efficiency observed for higher cyclotron harmonics in this multiple-pass absorption regime is attributed to the effect of an edge loss that competes with the core absorption mechanisms.

  19. Fast ion transport in solids: electrodes and electrolytes

    International Nuclear Information System (INIS)

    Vashishta, P.; Mundy, J.N.; Shenoy, G.K.

    1979-01-01

    Topics covered in the conference include: energy storage and other applications; electrode materials and intercalated compounds; diffusion; ionic conductivity techniques; neutron scattering and diffraction techniques; beta aluminas; deuterium and NH 4 ; NASICON and other sodium ion conductors; lithium ion conductors; silver and copper ion conductors; anion conductors; and high conductivity glasses. Thirty-five individual items were prepared separately for the data base

  20. Wave–particle resonances and redistribution/losses of fast ions in tokamaks

    International Nuclear Information System (INIS)

    Nabais, F.; Borba, D.; Kiptily, V.G.; Pinches, S.D.; Sharapov, S.E.

    2012-01-01

    Enhanced fast ion losses, mostly in the range of energies from around 1.2 to 2.4 MeV, were measured during the activity of tornado modes in the JET tokamak. Tornado modes are TAE localized inside the q = 1 surface, which do not extend to the outer regions of the plasma. Thus, it is necessary to find an explanation on how such modes can lead to the loss of fast ions. In this paper, a mechanism that allows explaining the loss of fast ions triggered by tornado modes is proposed. This mechanism is based on the combined effect of tornado modes and global TAEs over the fast ions (global TAEs were always observed along with the tornado modes in the experiments in which enhanced losses were measured). Tornado modes would trigger the process of loss by resonantly interacting with the fast ions near the centre of the plasma and transporting the ions to a more peripheral region where tornado modes and global TAEs coexist. The TAE would then transport convectively the fast ions, most efficiently through the first bounce resonances (p = 1), all the way to the plasma edge eventually leading to its loss. This mechanism of loss is supported by calculations carried out with the CASTOR-K code. (paper)

  1. Fast ion emission from the plasma produced by the PALS laser system

    International Nuclear Information System (INIS)

    Wolowski, J.; Badziak, J.; Boody, F.P.

    2002-01-01

    This paper presents the results of studies of fast ion emission from the multiply charged high-Z number plasma generated using the PALS high-energy iodine laser system (≤1.2 kJ, 0.4 ns) at the PALS Research Center in Prague. The properties of the emitted ion streams were investigated using ion collectors located at various angles with respect to the target normal and an electrostatic energy analyser. The x-ray emission from the plasma was measured using semiconductor detectors. Different groups of ions (slow, thermal and fast) were observed in the ion collector signals. Ion current densities higher than 80 mA cm -2 at ∼1 m from the target were demonstrated. The charge velocity distribution, ion current density and angular distribution of ion charge emission, as well as total charge and average ion energy were obtained from these signals. Using the electrostatic ion-energy analyser, the emission of highly charged heavy ions (Ta 52+ , Ag 38+ ) with energies up to 7 MeV for Ta ions was demonstrated. The dependence of ion stream parameters on the experimental conditions is discussed. We also report the results of preliminary experiments on the direct implantation of laser-produced ions into various materials. (author)

  2. A superconcentrated ether electrolyte for fast-charging Li-ion batteries.

    Science.gov (United States)

    Yamada, Yuki; Yaegashi, Makoto; Abe, Takeshi; Yamada, Atsuo

    2013-12-11

    We have found ultrafast Li(+) intercalation into graphite in a superconcentrated ether electrolyte, even exceeding that in a currently used commercial electrolyte. This discovery is an important breakthrough toward fast-charging Li-ion batteries far beyond present technologies.

  3. Energetic-particle-driven instabilities and induced fast-ion transport in a reversed field pinch

    International Nuclear Information System (INIS)

    Lin, L.; Brower, D. L.; Ding, W. X.; Anderson, J. K.; Capecchi, W.; Eilerman, S.; Forest, C. B.; Koliner, J. J.; Nornberg, M. D.; Reusch, J.; Sarff, J. S.; Liu, D.

    2014-01-01

    Multiple bursty energetic-particle (EP) driven modes with fishbone-like structure are observed during 1 MW tangential neutral-beam injection in a reversed field pinch (RFP) device. The distinguishing features of the RFP, including large magnetic shear (tending to add stability) and weak toroidal magnetic field (leading to stronger drive), provide a complementary environment to tokamak and stellarator configurations for exploring basic understanding of EP instabilities. Detailed measurements of the EP mode characteristics and temporal-spatial dynamics reveal their influence on fast ion transport. Density fluctuations exhibit a dynamically evolving, inboard-outboard asymmetric spatial structure that peaks in the core where fast ions reside. The measured mode frequencies are close to the computed shear Alfvén frequency, a feature consistent with continuum modes destabilized by strong drive. The frequency pattern of the dominant mode depends on the fast-ion species. Multiple frequencies occur with deuterium fast ions compared to single frequency for hydrogen fast ions. Furthermore, as the safety factor (q) decreases, the toroidal mode number of the dominant EP mode transits from n=5 to n=6 while retaining the same poloidal mode number m=1. The transition occurs when the m=1, n=5 wave-particle resonance condition cannot be satisfied as the fast-ion safety factor (q fi ) decreases. The fast-ion temporal dynamics, measured by a neutral particle analyzer, resemble a classical predator-prey relaxation oscillation. It contains a slow-growth phase arising from the beam fueling followed by a rapid drop when the EP modes peak, indicating that the fluctuation-induced transport maintains a stiff fast-ion density profile. The inferred transport rate is strongly enhanced with the onset of multiple EP modes

  4. Determining the stereochemical structures of molecular ions by ''Coulomb-explosion'' techniques with fast (MeV) molecular ion beams

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1980-01-01

    Recent studies on the dissociation of fast (MeV) molecular ion beams in thin foils suggest a novel alternative approach to the determination of molecular ion structures. In this article we review some recent high-resolution studies on the interactions of fast molecular ion beams with solid and gaseous targets and indicate how such studies may be applied to the problem of determining molecular ion structures. The main features of the Coulomb explosion of fast-moving molecular ion projectiles and the manner in which Coulomb-explosion techniques may be applied to the problem (difficult to attack by more conventional means) of determining the stereochemical structures of molecular ions has been described in this paper. Examples have been given of early experiments designed to elicit structure information. The techniques are still in their infancy, and it is to be expected that as both the technology and the analysis are refined, the method will make valuable contributions to the determination of molecular ion structures

  5. Production of fast ion and nuclei bunches of solid densities from nanolayers by ultrarelativistic laser pulses

    Directory of Open Access Journals (Sweden)

    H. K. Avetissian

    2011-10-01

    Full Text Available A method for generation of quasimonoenergetic, low emittance fast ion/nuclei bunches of solid densities from nanotargets by two counterpropagating laser pulses of ultrarelativistic intensities is proposed, based on the threshold phenomenon of particles reflection due to induced nonlinear Compton scattering. Particularly, a setup is considered which provides generation of ion bunches with parameters that are required in hadron therapy.

  6. Full inelastic cross section, effective stopping and ranges of fast multiply charged ions

    International Nuclear Information System (INIS)

    Alimov, R.A.; Arslanbekov, T.U.; Matveev, B.I.; Rakhmatov, A.S.

    1994-01-01

    Inelastic processes taking place in collision of fast multiply charged ions with atoms are considered on the base of mechanism of sudden momentum transfer. The simple estimations are proposed of full inelastic cross sections, effective stopping and ion ranges in gaseous medium. (author). 10 refs

  7. Symposium on fast atom and ion induced mass spectrometry of nonvolatile organic solids

    International Nuclear Information System (INIS)

    McNeal, C.J.

    1982-01-01

    The mechanisms of molecular and fragment ion production and the various parameters affecting ion yields were discussed by 6 invited speakers from Europe, Canada, and the US at this symposium. The work reported was almost equally divided between that using low-energy (keV) primary ion (or atom) beams, e.g. fast atom bombardment mass spectrometry (FABMS) and secondary ion mass spectrometry (SIMS) and that using high energy (MeV) particles, e.g. heavy ion induced mass spectrometry (HIIDMS) and 252 Cf-plasma desorption mass spectrometry ( 252 Cf-PDMS). Both theoretical foundations and observed experimental results for both techniques are included

  8. Studies of fast ion confinement in the MST Reversed Field Pinch*

    Science.gov (United States)

    Liu, D.; Almagri, A. F.; Anderson, J. K.; den Hartog, D. J.; Eilerman, S.; Nornberg, M. D.; Sarff, J. S.; Waksman, J.; Fiksel, G.; Belykh, V. V.; Deichuli, P.; Davydenko, V. I.; Ivanov, A. A.; Polosatkin, S.; Stupishin, N.

    2011-10-01

    Studies of fast ion confinement in the MST Reversed Field Pinch (RFP) are performed with a 1 MW hydrogen neutral beam injector (NBI), doped with 3-5% deuterium fuel for creation of beam-target fusion neutrons. It is found that fast ions born from co-current NBI are well confined and roughly consistent with classical behavior in spite of the RFP's stochastic magnetic field. The measured neutron decay times following a ~5 ms NBI pulse approximately agree with the prediction of classical slowing-down theory. The neutron flux at the beam turn-off time increases with plasma density and temperature, also as expected. The estimated fast ion confinement times range from several times to ten times the thermal particle confinement time, and charge-exchange with background neutrals seems to be the dominant fast ion loss mechanism. The slowing-down of fast protons is observed with a multi-energy-channel neutral particle analyzer. These results corroborate previous experiments with very short and low power neutral beam pulses, and are largely in agreement with TRANSP modeling which predicts a centrally peaked fast ion density profile with peak value up to 15% of the plasma density. *Work supported by USDOE.

  9. Fast Monte Carlo for ion beam analysis simulations

    International Nuclear Information System (INIS)

    Schiettekatte, Francois

    2008-01-01

    A Monte Carlo program for the simulation of ion beam analysis data is presented. It combines mainly four features: (i) ion slowdown is computed separately from the main scattering/recoil event, which is directed towards the detector. (ii) A virtual detector, that is, a detector larger than the actual one can be used, followed by trajectory correction. (iii) For each collision during ion slowdown, scattering angle components are extracted form tables. (iv) Tables of scattering angle components, stopping power and energy straggling are indexed using the binary representation of floating point numbers, which allows logarithmic distribution of these tables without the computation of logarithms to access them. Tables are sufficiently fine-grained that interpolation is not necessary. Ion slowdown computation thus avoids trigonometric, inverse and transcendental function calls and, as much as possible, divisions. All these improvements make possible the computation of 10 7 collisions/s on current PCs. Results for transmitted ions of several masses in various substrates are well comparable to those obtained using SRIM-2006 in terms of both angular and energy distributions, as long as a sufficiently large number of collisions is considered for each ion. Examples of simulated spectrum show good agreement with experimental data, although a large detector rather than the virtual detector has to be used to properly simulate background signals that are due to plural collisions. The program, written in standard C, is open-source and distributed under the terms of the GNU General Public License

  10. Nonlinear phenomenon in nanostructures creation by fast cluster ions

    Science.gov (United States)

    Moslem, W. M.; El-Said, A. S.; Sabry, R.; Shalouf, A.; El-Labany, S. K.; Bahlouli, H.

    2017-01-01

    The development of accelerators technology offers a new window for the creation of surface nanostructures in an efficient and accurate way. The use of 30 MeV C60 cluster ions enables the creation of nano-hillocks of size larger than the ones produced by GeV monoatomic ions. The physical mechanism underlying the realization of such nanostructures is elucidated using a plasma expansion approach. Numerical analysis showed that increasing the ionic temperature (number density) ratios would lead to decrease (increase) the nano-hillocks height.

  11. Inversion methods for fast-ion velocity-space tomography in fusion plasmas

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Stagner, L.; Salewski, Mirko

    2016-01-01

    Velocity-space tomography has been used to infer 2D fast-ion velocity distribution functions. Here we compare the performance of five different tomographic inversion methods: truncated singular value decomposition, maximum entropy, minimum Fisher information and zeroth and first-order Tikhonov re...... confidence regions, all methods agree that ions with pitch values close to zero, as well as ions with large pitch values, are ejected from the plasma center by the sawtooth crash, and that this ejection depletes the ion population with large pitch values more strongly....

  12. Self-consistent Study of Fast Particle Redistribution by Alfven Eigenmodes During Ion Cyclotron Resonance Heating

    International Nuclear Information System (INIS)

    Bergkvist, T.; Hellsten, T.; Johnson, T.

    2006-01-01

    Alfven eigenmodes (AEs) excited by fusion born α particles can degrade the heating efficiency of a burning plasma and throw out αs. To experimentally study the effects of excitation of AEs and the redistribution of the fast ions, ion cyclotron resonance heating (ICRH) is often used. The distribution function of thermonuclear αs in a reactor is expected to be isotropic and constantly renewed through DT reactions. The distribution function of cyclotron heated ions is strongly anisotropic, and the ICRH do not only renew the distribution function but also provide a strong decorrelation mechanism between the fast ions and the AE. Because of the sensitivity of the AE dynamics on the details of the distribution function, the location of the resonance surfaces in phase space and the extent of the overlapping resonant regions for different AEs, a self-consistent treatment of the AE excitation and the ICRH is necessary. Interactions of fast ions with AEs during ICRH has been implemented in the SELFO code. Simulations are in good agreement with the experimentally observer pitch-fork splitting and rapid damping of the AE as ICRH is turned off. The redistribution of fast ions have been studied in the presence of several driven AEs. (author)

  13. High-definition velocity-space tomography of fast-ion dynamics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Jacobsen, A.S.

    2016-01-01

    Velocity-space tomography of the fast-ion distribution function in a fusion plasma is usually a photon-starved tomography method due to limited optical access and signal-to-noise ratio of fast-ion Dα (FIDA) spectroscopy as well as the strive for high-resolution images. In high-definition tomography...... information to reconstruct where in velocity space the measurements and the simulation disagree. This alternative approach is demonstrated for four-view as well as for two-view FIDA measurements. The high-definition tomography tools allow us to study fast ions in sawtoothing plasmas and the formation of NBI...... peaks at full, half and one-third energy by time-resolved tomographic movies....

  14. Proceedings of the workshop on atomic physics with fast heavy-ion beams

    International Nuclear Information System (INIS)

    Kanter, E.P.; Minchinton, A.

    1983-01-01

    The Workshop on Atomic Physics with Fast Heavy-Ion Beams was held in the Physics Division, Argonne National Laboratory on January 20 and 21, 1983. The meeting brought together approx. 50 practitioners in the field of accelerator-based atomic physics. The workshop was held to focus attention on possible areas of atomic physics research which would benefit from use of the newest generation of accelerators designed to produce intense high-quality beams of fast heavy ions. Abstracts of individual paper were prepared separately for the data base

  15. Power deposition by neutral beam injected fast ions in field-reversed configurations

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

    2004-01-01

    The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

  16. Differential electron emission from polycyclic aromatic hydrocarbon molecules under fast ion impact

    OpenAIRE

    Biswas, Shubhadeep; Champion, Christophe; Tribedi, Lokesh C.

    2017-01-01

    Interaction between polycyclic aromatic hydrocarbon (PAH) molecule and energetic ion is a subject of interest in different areas of modern physics. Here, we present measurements of energy and angular distributions of absolute double differential electron emission cross section for coronene (C24H12) and fluorene (C13H10) molecules under fast bare oxygen ion impact. For coronene, the?angular distributions?of the low energy electrons are quite different from that of simpler targets like Ne or CH...

  17. Influence of excited states on the energy loss of fast ions in a hydrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, B. (Max-Planck-Institut fuer Quantenoptik, D-8046 Garching, Germany (DE)); Peter, T. (Max-Planck-Institut fuer Chemie, D-6500 Mainz, Germany (DE))

    1991-04-01

    Stopping power calculations of fast ions penetrating a hydrogen plasma target in local thermodynamic equilibrium at arbitrary temperatures are performed. Excited state contributions to the energy loss are included in the framework of the Bethe formalism. Average ionization potentials for the excited ions are given in a quasiclassical approximation. It is shown that the net effect is an enhancement of the stopping power compared to the energy loss when assuming all atoms to be in their ground state.

  18. Energy measurement of fast ions trapped in the toroidal field ripple of Tore Supra

    International Nuclear Information System (INIS)

    Basiuk, V.; Becoulet, A.; Hutter, T.; Martin, G.; Pecquet, A.L.; Saoutic, B.

    1993-09-01

    During additional heating in Tore Supra (ICRF or NBI) fast ion losses due to the toroidal field ripple were clearly measured by a set of graphite probes. This diagnostic collects the flow of fast ions entering a vertical port and usually shows a maximum flux for ions originating from the vicinity of surface δ * = 0. During the monster sawteeth regime, achieved with ICRF, a remarkable phenomenon was observed: the ejection of fast ions, not correlated with any measured MHD activity. The radial distribution of these ions is quite different from that usually observed exhibiting a peak located in the central section of the plasma. In order to measure the energy distribution of these ions, from 80 keV (energy of the neutral beam injected in Tore Supra) up to 1 MeV (expected during ICRF), a new diagnostic is under construction. The principle of the diagnostic is to discriminate the ions in energy using their Larmor radius (p = 1.3 cm for 100 keV → p = 3.6 cm for 700 keV, B = 4T). The detector is made of a hollow graphite cylinder with a small entrance slot, located in a vertical port on the ion drift side. An array of six metallic collectors placed inside the graphite cylinder intercepts the ions. The current on each collector was estimated at 10 → 100 nA, during ICRF heating. The energy resolution of this diagnostic is expected to be about 20 keV for the lowest energy range and 100 keV for the highest. This type of ruggedized detector might be extrapolated for the measurements of alpha particle losses in future DT experiments. It should also be suitable for the studies of stochastic ripple diffusion. (authors). 3 refs., 9 figs

  19. Generation of fast multiply charged ions in conical targets

    International Nuclear Information System (INIS)

    Demchenko, V.V.; Chukbar, K.V.

    1990-01-01

    So-called conical targets, when the thermonuclear fuel is compressed and heated in a conical cavity in a heavy material (lead, gold, etc.) with the help of a spherical segment that is accelerated by a laser pulse or a beam of charged particles, are often employed in experimental studies of inertial-confinement fusion. In spite of the obvious advantages of such a scheme, one of which is a significant reduction of the required energy input compared with the complete spherical target, it also introduces additional effects into the process of cumulation of energy. In this paper the authors call attention to an effect observed in numerical calculations: the hydrodynamic heating of a small group of multiply charged heavy ions of the walls of the conical cavity up to high energies (T i approx-gt 100 keV). This effect ultimately occurs as a result of the high radiation losses of a multiply charged plasma

  20. Ionization of water clusters by fast Highly Charged Ions: Stability, fragmentation, energetics and charge mobility

    International Nuclear Information System (INIS)

    Legendre, S; Maisonny, R; Capron, M; Bernigaud, V; Cassimi, A; Gervais, B; Grandin, J-P; Huber, B A; Manil, B; Rousseau, P; Tarisien, M; Adoui, L; Lopez-Tarifa, P; AlcamI, M; MartIn, F; Politis, M-F; Penhoat, M A Herve du; Vuilleumier, R; Gaigeot, M-P; Tavernelli, I

    2009-01-01

    We study dissociative ionization of water clusters by impact of fast Ni ions. Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility of the ionized clusters. An unusual stability of the (H 2 O) 4 H ''+ ion is observed, which could be the signature of the so called ''Eigen'' structure in gas phase water clusters. High charge mobility, responsible for the formation of protonated water clusters that dominate the mass spectrum, is evidenced. These results are supported by CPMD and TDDFT simulations, which also reveal the mechanisms of such mobility.

  1. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    International Nuclear Information System (INIS)

    Bindslev, H; Nielsen, S K; Porte, L; Hoekzema, J A; Korsholm, S B; Meo, F; Michelsen, P K; Michelsen, S; Oosterbeek, J W; Tsakadze, E L; Westerhof, E; Woskov, P

    2007-01-01

    The dynamics of fast ion populations in the TEXTOR tokamak are measured by collective Thomson scattering of millimetre wave radiation generated by a gyrotron operated at 110 GHz and 100-150 kW. Temporal evolution of the energetic ion velocity distribution at switch on of neutral beam injection (NBI) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also measured

  2. Fast argon ion irradiation effect on the characteristics of silicon planar structures

    CERN Document Server

    Karatetskii, S S; Sokolov, V I

    2002-01-01

    The effect of irradiating by the argon ions with the energy of 40 MeV on the planar structures parameters is studied with the purpose of determining the possibilities of their controlled change. It is shown, that the planar structures irradiation by the argon ions with the energy of 40 MeV leads to decrease in the capacitance of the MOS-condensers and narrows the area of the photosensitivity of the p - n-transitions. The observed effects are explained by the specificity of violations, created by fast ions in the crystal

  3. Preface: Photon and fast Ion induced Processes in Atoms, MOlecules and Nanostructures (PIPAMON)

    Science.gov (United States)

    Kövér, László

    2016-02-01

    This Special Issue contains selected papers of contributions presented in the International Workshop on Photon and fast Ion induced Processes in Atoms, MOlecules and Nanostructures (PIPAMON), held between March 24 and 26, 2015 in Debrecen, Hungary. The venue, the Aquaticum Thermal and Wellness Hotel provided a pleasant ;all-under-one-roof; environment for the event.

  4. Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

    Science.gov (United States)

    Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

    2012-10-01

    A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

  5. High-performance rechargeable batteries with fast solid-state ion conductors

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.

    2017-06-27

    A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.

  6. Fast-ion transport induced by Alfvén eigenmodes in the ASDEX Upgrade tokamak

    DEFF Research Database (Denmark)

    Garcia-Munoz, M.; Classen, I.G.J.; Geiger, B.

    2011-01-01

    A comprehensive suite of diagnostics has allowed detailed measurements of the Alfvén eigenmode (AE) spatial structure and subsequent fast-ion transport in the ASDEX Upgrade (AUG) tokamak [1]. Reversed shear Alfvén eigenmodes (RSAEs) and toroidal induced Alfvén eigenmodes (TAEs) have been driven u...

  7. Actin filaments as the fast pathways for calcium ions involved in ...

    Indian Academy of Sciences (India)

    ... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Biosciences; Volume 40; Issue 3. Actin filaments as the fast pathways for calcium ions involved in auditory processes. Miljko V Sataric Dalibor L Sekulic Bogdan M Sataric. Articles Volume 40 Issue 3 September 2015 pp 549- ...

  8. Spatial distribution of ion charges in fast, partially stripped clusters traversing solid targets

    CERN Document Server

    Miskovic, Z L; Goodman, F O; Wang, Y N

    2002-01-01

    Joint statistical description of the distribution of ion charge states and the spatial structure of a cluster, made of heavy ions, allows a self-consistent generalization of the Brandt-Kitagawa variational theory, including dynamically-screened inter-ionic interactions, in a form of a non-linear integral equation. Solution of such an equation for fast clusters passing very thin foils shows the familiar reduction of charge per ion, compared to the charge on an isotactic ion, which is rather non-homogeneously distributed throughout the volume of the cluster. As a consequence, the distribution of individual ion charges in the cluster exhibits large dispersion around an average value, which drops with the increasing cluster size.

  9. High Precision, Sensitive, Near-IR Spectroscopy in a Fast Ion Beam

    Science.gov (United States)

    Porambo, Michael; Kreckel, Holger; Mills, Andrew; Perera, Manori; Siller, Brian; McCall, Benjamin J.

    2011-10-01

    In the low temperatures and pressures of the interstellar medium (ISM), molecular ions play key roles as reactants and intermediates, as well as physical probes of the interstellar environment. As such, high resolution laboratory spectra of these ions aid in further understanding the chemistry and physics of the ISM. There are many challenges to high resolution molecular ion spectroscopy in the laboratory, though. To combat these challenges, we have built a fast ion beam spectrometer that possesses rigorous ion-neutral discrimination, high sensitivity and resolution, and mass identification capabilities. The primary components of the system are a cold cathode ion source, an electrostatic ion optical system for steering and focusing the extracted ion beam, an ion beam-laser overlap region where the spectroscopy takes place, and a time-of-flight mass spectrometer for mass studies of the ion beam. The spectra are obtained using a highly sensitive spectroscopic technique called Noise Immune Cavity Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS). By calibrating the spectra with an optical frequency comb, line centers of transitions can be determined to future, a supersonic expansion discharge source will take the place of the current cold cathode in order to create an ion beam with much lower rotational temperature. We have recorded near-infrared rovibronic transitions of the 1-0 Meinel band of N2+as a proof of concept of this setup. In addition to analyzing the lineshapes of the transitions, the line center of the Q22(14.5) line was determined to an accuracy of ~8 MHz. Presently, we are working to extend our ion beam spectroscopy to the study of mid-infrared vibrational transitions of other molecular ions using a Difference Frequency Generation (DFG) laser tunable from 2.8 to 4.8 μm.

  10. Quantification of the impact of large and small-scale instabilities on the fast-ion confinement in ASDEX Upgrade

    DEFF Research Database (Denmark)

    Geiger, B.; Weiland, M.; Mlynek, A.

    2015-01-01

    with up to 10 MW of heating power, the fast-ion measurements agree best with the theoretical predictions that assume a weak level anomalous fast-ion transport. This is also in agreement with measurements of the internal inductance, a Motional Stark Effect diagnostic and a novel polarimetry diagnostic...

  11. First fast-ion D-alpha (FIDA) measurements and simulations on C-2U

    Energy Technology Data Exchange (ETDEWEB)

    Bolte, N. G., E-mail: nbolte@TriAlphaEnergy.com; Gupta, D.; Onofri, M.; Dettrick, S.; Granstedt, E. M.; Petrov, P. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States); Stagner, L. [University of California, Irvine, Irvine, California 92697 (United States)

    2016-11-15

    The first measurements of fast-ion D-alpha (FIDA) radiation have been acquired on C-2U, Tri Alpha Energy’s advanced, beam-driven field-reversed configuration (FRC). These measurements are also forward modeled by FIDASIM. This is the first measurement and simulation of FIDA carried out on an FRC topology. FIDA measurements are made of Doppler-shifted Balmer-alpha light from neutralized fast ions using a bandpass filter and photomultiplier tube. One adjustable line-of-sight measured signals at eight locations and eight times during the FRC lifetime over 26 discharges. Filtered signals include only the highest energy ions (>6 keV) and share some salient features with the FIDASIM result. Highly Doppler-shifted beam radiation is also measured with a high-speed camera and is spatially well-correlated with FIDASIM.

  12. Recent progress of fast-ion loss detector project in Asian fusion experiments

    International Nuclear Information System (INIS)

    Isobe, Mitsutaka; Zhang Yipo; Kim, Jun-Young

    2013-01-01

    The A3 foresight program is accelerating close collaboration for fast-ion diagnostics development between Asian three countries. A recent big step in our activities is that the operation of fast-ion loss detector (FILD) on HL-2A has begun lately. The localized bright spot appeared on the scintillator screen while a high-energy neutral beam was tangentially co-injected. The design of FILD system on EAST is steadily ongoing. The diagnostics port available for our purpose was decided in March, 2013. For KSTAR, the FILD is working successfully. In order to understand observed beam-ion loss signals while the RMP coils are turned on, the LORBIT code has been improved recently to treat non-axisymmetric perturbed field due to RMP coils and discreteness of TF coils. (author)

  13. Trapping ions from a fast beam in a radio-frequency ion trap: Exploring the energy exchange with the longitudinal radio-frequency field

    DEFF Research Database (Denmark)

    Svendsen, Annette; Lammich, Lutz; Vad Andersen, John Erik

    2013-01-01

    The possibility of injecting ions from an initially fast moving beam into a multipole radio-frequency (RF) ion trap without the use of buffer gas is described. The chosen trap geometry gives rise to an oscillating electric field along the direction of the incoming ions, and through an analytical...

  14. Validation of fast-ion D-alpha spectrum measurements during EAST neutral-beam heated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J., E-mail: juan.huang@ipp.ac.cn; Wu, C. R.; Hou, Y. M.; Chang, J. F.; Ding, S. Y.; Chen, Y. J.; Jin, Z.; Xu, Z.; Gao, W.; Wang, J. F.; Lyu, B.; Zang, Q.; Zhong, G. Q.; Hu, L.; Wan, B. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui (China); Heidbrink, W. W.; Stagner, L.; Zhu, Y. B. [University of California, Irvine, California 92697 (United States); Hellermann, M. G. von [Diagnostic Team, ITER Organization, Route de Vinon-sur-Verdon 13067 St. Paul Lez Durance (France)

    2016-11-15

    To investigate the fast ion behavior, a fast ion D-alpha (FIDA) diagnostic system has been installed on EAST. Fast ion features can be inferred from the Doppler shifted spectrum of Balmer-alpha light from energetic hydrogenic atoms. This paper will focus on the validation of FIDA measurements performed using MHD-quiescent discharges in 2015 campaign. Two codes have been applied to calculate the D{sub α} spectrum: one is a Monte Carlo code, Fortran 90 version FIDASIM, and the other is an analytical code, Simulation of Spectra (SOS). The predicted SOS fast-ion spectrum agrees well with the measurement; however, the level of fast-ion part from FIDASIM is lower. The discrepancy is possibly due to the difference between FIDASIM and SOS velocity distribution function. The details will be presented in the paper to primarily address comparisons of predicted and observed spectrum shapes/amplitudes.

  15. Edge Ion Heating by Launched High Harmonic Fast Waves in NSTX

    International Nuclear Information System (INIS)

    Biewer, T.M.; Bell, R.E.; Diem, S.J.; Phillips, C.K.; Wilson, J.R.; Ryan, P.M.

    2004-01-01

    A new spectroscopic diagnostic on the National Spherical Torus Experiment (NSTX) measures the velocity distribution of ions in the plasma edge simultaneously along both poloidal and toroidal views. An anisotropic ion temperature is measured during high-power high harmonic fast wave (HHFW) radio-frequency (rf) heating in helium plasmas, with the poloidal ion temperature roughly twice the toroidal ion temperature. Moreover, the measured spectral distribution suggests that two populations of ions are present and have temperatures of typically 500 eV and 50 eV with rotation velocities of -50 km/s and -10 km/s, respectively (predominantly perpendicular to the local magnetic field). This bi-modal distribution is observed in both the toroidal and poloidal views (for both He + and C 2+ ions), and is well correlated with the period of rf power application to the plasma. The temperature of the hot component is observed to increase with the applied rf power, which was scanned between 0 and 4.3 MW . The 30 MHz HHFW launched by the NSTX antenna is expected and observed to heat core electrons, but plasma ions do not resonate with the launched wave, which is typically at >10th harmonic of the ion cyclotron frequency in the region of observation. A likely ion heating mechanism is parametric decay of the launched HHFW into an Ion Bernstein Wave (IBW). The presence of the IBW in NSTX plasmas during HHFW application has been directly confirmed with probe measurements. IBW heating occurs in the perpendicular ion distribution, consistent with the toroidal and poloidal observations. Calculations of IBW propagation indicate that multiple waves could be created in the parametric decay process, and that most of the IBW power would be absorbed in the outer 10 to 20 cm of the plasma, predominantly on fully stripped ions. These predictions are in qualitative agreement with the observations, and must be accounted for when calculating the energy budget of the plasma

  16. Longitudinal instabilities of the experimentally generated laser accelerated ion beam relevant to fast ignition

    Science.gov (United States)

    Khoshbinfar, S.

    2017-11-01

    The advent of laser-assisted ion acceleration technology promises an alternative candidate to conventional accelerator drivers used in inertial confinement fusion. The experimental generation of quasi-monoenergetic heavier ion species i.e. carbon and aluminum, applicable to fast ignition studies has been recently reported. The propagation of these energetic ions may impact on the proper ignition phase through growing of micro-instabilities of beam-plasma system. The growth of flow-aligned instabilities is much more important for heavier ions transport in the dense plasma. Here, we have presented a general non-relativistic one-dimensional dispersion relation of cold fluid model as well as corresponding kinetic theory of incident ion beam with atomic number, Zb enters into a fast ignition DT plasma. The longitudinal instabilities of some selected average energies of experimentally generated C6+ (EC=50, 100 and 200 MeV with δE/E ∼ 10 %) and Al11+ (EAl=150 and 300 MeV with δE/E ∼25%) quasi-monoenergetic beams were examined and beam-plasma system stable configuration have been then derived. It has been shown that in the kinetic theory framework, carbon and aluminum ions may be completely stabilized by the combination of beam to plasma density ratio (αb) and plasma temperature (Tp) of ignition phase parameters. Moreover, in complete stabilization, αb parameter of aluminum beam is an order of magnitude lower than carbon.

  17. Plasma mirror implementation on LFEX laser for ion and fast electron fast ignition

    Science.gov (United States)

    Morace, A.; Kojima, S.; Arikawa, Y.; Fujioka, S.; Yogo, A.; Tosaki, S.; Sakata, S.; Abe, Y.; Lee, S. H.; Matsuo, K.; Sagisaka, A.; Kondo, K.; Pirozhkov, A. S.; Norimatsu, T.; Jitsuno, T.; Miyanaga, N.; Shiraga, H.; Nakai, M.; Nishimura, H.; Azechi, H.

    2017-12-01

    In this work we report the successful implementation of plasma mirror (PM) technology on an LFEX laser facility at the Institute of Laser Engineering, Osaka University. The LFEX laser pulse was successfully refocused at the target chamber center (TCC) by means of a spherical plasma mirror, resulting in 5  ×  1018 W cm-2 laser intensity, with 45% reflectivity at a laser flux of about 90 J cm-2 on the PM. Experimental results show stable focusing and pointing of the LFEX pulse after PM refocusing. The contrast improvement was demonstrated by both cooler fast electron slope temperature distribution as well as by the ability to shoot sub-µm plastic foils obtaining proton beams with maximum energy exceeding 20 MeV. Experimental results are qualitatively reproduced by 2D particle in cell simulations.

  18. Advanced ion beam analysis of materials using ion-induced fast electron

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Hiroshi; Tanabe, Atsushi; Ishihara, Toyoyuki [Tsukuba Univ., Ibaraki (Japan)] [and others

    1997-03-01

    Recent progress in the study of high-energy shadowing effect using ion-induced electron spectroscopy is reported with emphasis on a possibility of determination of local electronic structure in solids, which has been a difficult problem to approach with other experimental techniques. We demonstrate real-space determination of covalent-bond electron distribution in Si crystal. The analysis technique may provide a new field of ion beam analysis of solids. (author)

  19. ITER Plasma at Ion Cyclotron Frequency Domain: The Fusion Alpha Particles Diagnostics Based on the Stimulated Raman Scattering of Fast Magnetosonic Wave off High Harmonic Ion Bernstein Modes

    Science.gov (United States)

    Stefan, V. Alexander

    2014-10-01

    A novel method for alpha particle diagnostics is proposed. The theory of stimulated Raman scattering, SRS, of the fast wave and ion Bernstein mode, IBM, turbulence in multi-ion species plasmas, (Stefan University Press, La Jolla, CA, 2008). is utilized for the diagnostics of fast ions, (4)He (+2), in ITER plasmas. Nonlinear Landau damping of the IBM on fast ions near the plasma edge leads to the space-time changes in the turbulence level, (inverse alpha particle channeling). The space-time monitoring of the IBM turbulence via the SRS techniques may prove efficient for the real time study of the fast ion velocity distribution function, spatial distribution, and transport. Supported by Nikola Tesla Labs., La Jolla, CA 92037.

  20. Spectroscopic Measurements of the Ion Velocity Distribution at the Base of the Fast Solar Wind

    Science.gov (United States)

    Jeffrey, Natasha L. S.; Hahn, Michael; Savin, Daniel W.; Fletcher, Lyndsay

    2018-03-01

    In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons, and minor ions extending from 0.3 au to the heliopause. The physical mechanisms responsible for these non-thermal properties and the location where these properties originate remain open questions. Here, we present spectroscopic evidence, from extreme ultraviolet spectroscopy, that the velocity distribution functions (VDFs) of minor ions are already non-Gaussian at the base of the fast solar wind in a coronal hole, at altitudes of thermal equilibrium, (b) fluid motions such as non-Gaussian turbulent fluctuations or non-uniform wave motions, or (c) some combination of both. These observations provide important empirical constraints for the source region of the fast solar wind and for the theoretical models of the different acceleration, heating, and energy deposition processes therein. To the best of our knowledge, this is the first time that the ion VDF in the fast solar wind has been probed so close to its source region. The findings are also a timely precursor to the upcoming 2018 launch of the Parker Solar Probe, which will provide the closest in situ measurements of the solar wind at approximately 0.04 au (8.5 solar radii).

  1. An analysis of the influence of impurities on fast particle attenuation and on fast ion spectral shape in LHD.

    Science.gov (United States)

    Veshchev, Evgeny A; Goncharov, Pavel R; Ozaki, Tetsuo; Sudo, Shigeru

    2008-10-01

    Neutral particle fluxes measured by neutral particle analyzers can provide information about the ion temperature as well as the non-Maxwellian anisotropic ion distribution tails from neutral beam injection and ion cyclotron radio frequency heating. In the case of multidirectional diagnostics employing high resolution atomic energy spectrometers, the neutral atomic flux source is not localized in contrast to pellet charge exchange or diagnostic neutral beam methods. The correct interpretation of such measurements from plasma in a complex toroidally asymmetric geometry, like that of LHD, requires careful numerical modeling of the neutral flux formation. Previously a measured neutral flux calculation scheme was developed and was used for the LHD geometry and a suitable analytic expression for ionization cross sections sigma(s)(z)(E,n(e),T(e),Z(eff)) of impurities was formulated by Janev et al. [Nucl. Fusion 29, 2125 (1989)]. In this paper, the attenuation of fast particles by impurities is incorporated into the neutral flux calculation scheme and the influence of impurities on the calculated neutral flux spectra is shown. Finally, the behavior of the calculated and experimental suprathermal particle distributions is compared for pure hydrogen and for argon impurity seeded plasmas.

  2. Experimental studies of fast deuterons, impurity- and admixture-ions emitted from a plasma focus

    International Nuclear Information System (INIS)

    Mozer, A.; Sadowski, M.; Herold, H.; Schmidt, H.

    1982-01-01

    The energy and mass analysis of ions emitted from a 50-kJ, 18-kV, plasma focus machine was performed with a Thomson analyzer. Energy distribution functions of fast deuterons (E> or =350 keV) and those of impurity ions have been determined. The energy distributions of the O, N, and C impurity ions in different ionization states have similar character. They usually increase exponentially and after reaching the maximum at E/Zroughly-equal1.0 MeV they decrease exponentially to E/Zroughly-equal1.8 MeV. For deuterons at lower operating pressures (p 0 + -Ar 7+ ions of energy from 0.5 to 14 MeV are produced

  3. Coherent Structures at Ion Scales in Fast Solar Wind: Cluster Observations

    Science.gov (United States)

    Perrone, D.; Alexandrova, O.; Roberts, O. W.; Lion, S.; Lacombe, C.; Walsh, A.; Maksimovic, M.; Zouganelis, I.

    2017-11-01

    We investigate the nature of magnetic turbulent fluctuations, around ion characteristic scales, in a fast solar wind stream, by using Cluster data. Contrarily to slow solar wind, where both Alfvénic (δ {b}\\perp \\gg δ {b}\\parallel ) and compressive (δ {b}\\parallel \\gg δ {b}\\perp ) coherent structures are observed, the turbulent cascade of fast solar wind is dominated by Alfvénic structures, namely, Alfvén vortices, with a small and/or finite compressive part, with the presence also of several current sheets aligned with the local magnetic field. Several examples of vortex chains are also recognized. Although an increase of magnetic compressibility around ion scales is observed also for fast solar wind, no strongly compressive structures are found, meaning that the nature of the slow and fast winds is intrinsically different. Multispacecraft analysis applied to this interval of fast wind indicates that the coherent structures are almost convected by the flow and aligned with the local magnetic field, I.e., their normal is perpendicular to {\\boldsymbol{B}}, which is consistent with a two-dimensional turbulence picture. Understanding intermittency and the related generation of coherent structures could provide a key insight into the nonlinear energy transfer and dissipation processes in magnetized and collisionless plasmas.

  4. Exit points, on plasma, of lost fast ions during NBI in TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.

    1995-01-01

    The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between, the position of those exit points and the corresponding at birth, orbits and drifts is analysed also. It is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II. (Author) 2 refs

  5. Exit points, on plasma, of lost fast ions during NBI in TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.

    1995-09-01

    The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between the position of those exit points and the corresponding at birth, orbits and drifts is analysed also, it is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II

  6. Fast Ion Instability in the CLIC Transfer Line and Main LINAC

    CERN Document Server

    Rumolo, G

    2008-01-01

    The Fast Ion Instability is believed to be a serious danger for bunch trains propagating in the CLIC electron transfer line and main linac, since it may strongly affect the bunches in the tail of the train if the vacuum pressure is not below a certain threshold. We have developed the FASTION code, which can track electrons through a FODO cell line and takes into account their interactions with the produced (and possibly trapped) ions. We describe how this tool can be used for setting tolerances on the vacuum pressure and for giving specifications for the design of a feedback system.

  7. Velocity space resolved absolute measurement of fast ion losses induced by a tearing mode in the ASDEX Upgrade tokamak

    Science.gov (United States)

    Galdon-Quiroga, J.; Garcia-Munoz, M.; Sanchis-Sanchez, L.; Mantsinen, M.; Fietz, S.; Igochine, V.; Maraschek, M.; Rodriguez-Ramos, M.; Sieglin, B.; Snicker, A.; Tardini, G.; Vezinet, D.; Weiland, M.; Eriksson, L. G.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2018-03-01

    Absolute flux of fast ion losses induced by tearing modes have been measured by means of fast ion loss detectors (FILD) for the first time in RF heated plasmas in the ASDEX Upgrade tokamak. Up to 30 MW m‑2 of fast ion losses are measured by FILD at 5 cm from the separatrix, consistent with infra-red camera measurements, with energies in the range of 250–500 keV and pitch angles corresponding to large trapped orbits. A resonant interaction between the fast ions in the high energy tail of the ICRF distribution and a m/n  =  5/4 tearing mode leads to enhanced fast ion losses. Around 9.3 +/- 0.7 % of the fast ion losses are found to be coherent with the mode and scale linearly with its amplitude, indicating the convective nature of the transport mechanism. Simulations have been carried out to estimate the contribution of the prompt losses. A good agreement is found between the simulated and the measured velocity space of the losses. The velocity space resonances that may be responsible for the enhanced fast ion losses are identified.

  8. Inversion methods for fast-ion velocity-space tomography in fusion plasmas

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Stagner, L.; Salewski, Mirko

    2016-01-01

    Velocity-space tomography has been used to infer 2D fast-ion velocity distribution functions. Here we compare the performance of five different tomographic inversion methods: truncated singular value decomposition, maximum entropy, minimum Fisher information and zeroth and first-order Tikhonov...... regularization. The inversion methods are applied to fast-ion Dα measurements taken just before and just after a sawtooth crash in the ASDEX Upgrade tokamak as well as to synthetic measurements from different test distributions. We find that the methods regularizing by penalizing steep gradients or maximizing...... entropy perform best. We assess the uncertainty of the calculated inversions taking into account photon noise, uncertainties in the forward model as well as uncertainties introduced by the regularization which allows us to distinguish regions of high and low confidence in the tomographies. In high...

  9. Repetitive outbursts of fast carbon and fluorine ions from sub-nanosecond laser-produced plasma

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Velyhan, Andriy; Jungwirth, Karel; Krouský, Eduard; Láska, Leoš; Rohlena, Karel; Pfeifer, Miroslav; Ullschmied, Jiří

    2009-01-01

    Roč. 27, č. 1 (2009), 171-178 ISSN 0263-0346 R&D Projects: GA MŠk(CZ) LC528; GA AV ČR IAA100100715 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser-produced plasma * outbursts of fast ions Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.420, year: 2008

  10. Bayesian Integrated Data Analysis of Fast-Ion Measurements by Velocity-Space Tomography

    DEFF Research Database (Denmark)

    Salewski, M.; Nocente, M.; Jacobsen, A.S.

    2018-01-01

    Bayesian integrated data analysis combines measurements from different diagnostics to jointly measure plasma parameters of interest such as temperatures, densities, and drift velocities. Integrated data analysis of fast-ion measurements has long been hampered by the complexity of the strongly non...... framework. The implementation for different types of diagnostics as well as the uncertainties are discussed, and we highlight the importance of integrated data analysis of all available detectors....

  11. Physics with fast molecular-ion beams. Proceedings of workshop held at Argonne National Laboratory, August 20-21, 1979

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1979-01-01

    The Workshop on Physics with Fast Molecular-Ion Beams was held in the Physics Division, Argonne National Laboratory on August 20 and 21, 1979. The meeting brought together representatives from several groups studying the interactions of fast (MeV) molecular-ion beams with matter. By keeping the Workshop program sharply focussed on current work related to the interactions of fast molecular ions, it was made possible for the participants to engage in vigorous and detailed discussions concerning such specialized topics as molecular-ion dissociation and transmission, wake effects, ionic charge states, cluster stopping powers, beam-foil spectroscopy, electron-emissions studies with molecular-ion beams, and molecular-ion structure determinations

  12. COHERENT EVENTS AND SPECTRAL SHAPE AT ION KINETIC SCALES IN THE FAST SOLAR WIND TURBULENCE

    International Nuclear Information System (INIS)

    Lion, Sonny; Alexandrova, Olga; Zaslavsky, Arnaud

    2016-01-01

    In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic to sub-ion scales using in situ measurements of the Wind spacecraft in a fast stream. For the time interval investigated by Leamon et al. (1998) the phase coherence analysis shows the presence of sporadic quasi-parallel Alfvén ion cyclotron (AIC) waves as well as coherent structures in the form of large-amplitude, quasi-perpendicular Alfvén vortex-like structures and current sheets. These waves and structures importantly contribute to the observed power spectrum of magnetic fluctuations around ion scales; AIC waves contribute to the spectrum in a narrow frequency range whereas the coherent structures contribute to the spectrum over a wide frequency band from the inertial range to the sub-ion frequency range. We conclude that a particular combination of waves and coherent structures determines the spectral shape of the magnetic field spectrum around ion scales. This phenomenon provides a possible explanation for a high variability of the magnetic power spectra around ion scales observed in the solar wind.

  13. Electroless formation of hybrid lithium anodes for fast interfacial ion transport

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Snehashis; Stalin, Sanjuna; Vu, Duylinh; Fawole, Kristen; Archer, Lynden A. [School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY (United States); Tu, Zhengyuan [Department of Material Science and Engineering, Cornell University, Ithaca, NY (United States); Gunceler, Deniz [Department of Physics, Cornell University, Ithaca, NY (United States); Sundararaman, Ravishankar [Material Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY (United States)

    2017-10-09

    Rechargeable batteries based on metallic anodes are of interest for fundamental and application-focused studies of chemical and physical kinetics of liquids at solid interfaces. Approaches that allow facile creation of uniform coatings on these metals to prevent physical contact with liquid electrolytes, while enabling fast ion transport, are essential to address chemical instability of the anodes. Here, we report a simple electroless ion-exchange chemistry for creating coatings of indium on lithium. By means of joint density functional theory and interfacial characterization experiments, we show that In coatings stabilize Li by multiple processes, including exceptionally fast surface diffusion of lithium ions and high chemical resistance to liquid electrolytes. Indium coatings also undergo reversible alloying reactions with lithium ions, facilitating design of high-capacity hybrid In-Li anodes that use both alloying and plating approaches for charge storage. By means of direct visualization, we further show that the coatings enable remarkably compact and uniform electrodeposition. The resultant In-Li anodes are shown to exhibit minimal capacity fade in extended galvanostatic cycling when paired with commercial-grade cathodes. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Electroless Formation of Hybrid Lithium Anodes for Fast Interfacial Ion Transport

    KAUST Repository

    Choudhury, Snehashis

    2017-08-17

    Rechargeable batteries based on metallic anodes are of interest for fundamental and application-focused studies of chemical and physical kinetics of liquids at solid interfaces. Approaches that allow facile creation of uniform coatings on these metals to prevent physical contact with liquid electrolytes, while enabling fast ion transport, are essential to address chemical instability of the anodes. Here, we report a simple electroless ion-exchange chemistry for creating coatings of indium on lithium. By means of joint density functional theory and interfacial characterization experiments, we show that In coatings stabilize Li by multiple processes, including exceptionally fast surface diffusion of lithium ions and high chemical resistance to liquid electrolytes. Indium coatings also undergo reversible alloying reactions with lithium ions, facilitating design of high-capacity hybrid In-Li anodes that use both alloying and plating approaches for charge storage. By means of direct visualization, we further show that the coatings enable remarkably compact and uniform electrodeposition. The resultant In-Li anodes are shown to exhibit minimal capacity fade in extended galvanostatic cycling when paired with commercial-grade cathodes.

  15. Electroless Formation of Hybrid Lithium Anodes for Fast Interfacial Ion Transport.

    Science.gov (United States)

    Choudhury, Snehashis; Tu, Zhengyuan; Stalin, Sanjuna; Vu, Duylinh; Fawole, Kristen; Gunceler, Deniz; Sundararaman, Ravishankar; Archer, Lynden A

    2017-10-09

    Rechargeable batteries based on metallic anodes are of interest for fundamental and application-focused studies of chemical and physical kinetics of liquids at solid interfaces. Approaches that allow facile creation of uniform coatings on these metals to prevent physical contact with liquid electrolytes, while enabling fast ion transport, are essential to address chemical instability of the anodes. Here, we report a simple electroless ion-exchange chemistry for creating coatings of indium on lithium. By means of joint density functional theory and interfacial characterization experiments, we show that In coatings stabilize Li by multiple processes, including exceptionally fast surface diffusion of lithium ions and high chemical resistance to liquid electrolytes. Indium coatings also undergo reversible alloying reactions with lithium ions, facilitating design of high-capacity hybrid In-Li anodes that use both alloying and plating approaches for charge storage. By means of direct visualization, we further show that the coatings enable remarkably compact and uniform electrodeposition. The resultant In-Li anodes are shown to exhibit minimal capacity fade in extended galvanostatic cycling when paired with commercial-grade cathodes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effects of fast monoenergetic electrons on the ion dynamics near the cathode in a pulsed direct current plasma sheath

    International Nuclear Information System (INIS)

    Sharifian, M.; Shokri, B.

    2008-01-01

    A detailed one-dimensional simulation of the ion dynamics of the plasma sheath near a substrate (cathode) in the presence of fast monoenergetic electrons has been carried out in this article. The sheath evolution is investigated by using a fluid model assuming that the ions, plasma electrons and monoenergetic, fast electrons act as three fluids (fluid approach). The effect of the density of fast electrons on the ion density, ion velocity, and ion energy near the cathode and the evolution of the sheath boundary in front of the cathode are separately explored. Also, the variation of the ion velocity and ion density at the vicinity of the cathode as a function of time is investigated in the absence and presence of the electron beam. Results indicate that the presence of fast electrons in the sheath causes significant change in the sheath thickness and therefore basically changes the ion velocity, ion density, and ion impact energy on the cathode compared to the absence of the electron beam case

  17. Fast heavy-ion radiation damage of glycine in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Shinji [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan); Furuya, Ryosuke [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya; Itoh, Akio [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan)

    2016-12-15

    Fast heavy-ion radiolysis of biomolecules in aqueous solution is investigated for an atomistic understanding of radiation damage to normal cells during heavy-particle beam therapy. The smallest amino acid glycine was used as a model biomaterial. Microjets of aqueous glycine solutions under vacuum were irradiated with 4.0-MeV carbon ions corresponding to energies in the Bragg peak region. To understand the effects of the water environment on molecular damage, the yield of glycine dissociation was measured by secondary ion mass spectroscopy. The yield was significantly reduced relative to gas-phase glycine targets. This implies that the numerous water molecules surrounding a single glycine molecule act as a buffer that suppresses dissociation. This is an environmental effect similar to that observed for other biomolecular cluster targets.

  18. Energy losses of fast heavy-ion projectiles in dense hydrogen plasmas

    International Nuclear Information System (INIS)

    Ballester, D; Tkachenko, I M

    2009-01-01

    It has recently been shown that the Bethe-Larkin formula for the energy losses of fast heavy-ion projectiles in dense hydrogen plasmas is corrected by the electron-ion correlations (Ballester and Tkachenko 2008 Phys. Rev. Lett. 101 075002). We report numerical estimates of this correction based on the values of g ei (0) obtained by numerical simulations (Militzer and Pollock 2000 Phys. Rev. E 61 3470). We also extend this result to the case of projectiles with dicluster charge distribution. We show that the experimental visibility of the electron-ion correlation correction is enhanced in the case of dicluster projectiles with randomly orientated charge centers. Although we consider here the hydrogen plasmas to make the effect physically more clear, the generalization to multispecies plasmas is straightforward

  19. Energy losses of fast heavy-ion projectiles in dense hydrogen plasmas

    Science.gov (United States)

    Ballester, D.; Tkachenko, I. M.

    2009-05-01

    It has recently been shown that the Bethe-Larkin formula for the energy losses of fast heavy-ion projectiles in dense hydrogen plasmas is corrected by the electron-ion correlations (Ballester and Tkachenko 2008 Phys. Rev. Lett. 101 075002). We report numerical estimates of this correction based on the values of gei(0) obtained by numerical simulations (Militzer and Pollock 2000 Phys. Rev. E 61 3470). We also extend this result to the case of projectiles with dicluster charge distribution. We show that the experimental visibility of the electron-ion correlation correction is enhanced in the case of dicluster projectiles with randomly orientated charge centers. Although we consider here the hydrogen plasmas to make the effect physically more clear, the generalization to multispecies plasmas is straightforward.

  20. Ejection of fast recoil atoms from solids under ion bombardment (medium-energy ion scattering by solid surfaces: Pt. 3)

    International Nuclear Information System (INIS)

    Dodonoy, A.I.; Mashkova, E.S.; Molchanov, V.A.

    1989-01-01

    This paper is the third part of our review surface scattering. Part I, which was devoted to the scattering of ions by the surfaces of disordered solids, was published in 1972; Part II, concerning scattering by crystal surfaces, was published in 1974. Since the publication of these reviews the material contained in them has become obsolete in many respects. A more recent account of the status of the problem has been given in a number of studies, including the book by E.S. Mashkova and V.A. Molchanov, Medium-Energy Ion Scattering by Solid Surfaces (Atomizdat, Moscow, 1980), than extended version of which was published by North-Holland in 1985. We note, however, that at the time these reviews were written the study of fast recoil atoms had not been carried out systematically; the problem was studied only as a by-product of surface scattering and sputtering. For this reason, in the above-mentioned works and in other reviews the data relating to recoil atoms were considered only occasionally. In recent years there have appeared a number of works - theoretical, experimental and computer -specially devoted to the study of the ejection of recoil atoms under ion bombardment. A number of interesting effects, which are due to the crystal structure of the target, have been discovered. It therefore, appeared desirable to us to systematize the available material and to present it as Part III of our continuing review. (author)

  1. Re-entering fast ion effects on NBI heating power in high-beta plasmas of the Large Helical Device

    International Nuclear Information System (INIS)

    Seki, Ryosuke; Watanabe, Kiyomasa; Funaba, Hisamichi; Suzuki, Yasuhiro; Sakakibara, Satoru; Ohdachi, Satoshi; Matsumoto, Yutaka; Hamamatsu, Kiyotaka

    2011-10-01

    We calculate the heating power of the neutral beam injection (NBI) in the = 4.8% high-beta discharge achieved in the Large Helical Device (LHD). We investigate the difference of the heating efficiency and the heating power profile between with and without the re-entering fast ion effects. When the re-entering fast ion effects are taken into account, the heating efficiency in the co injection of the NBI (co-NBI case) is improved and it is about 1.8 times larger than that without the re-entering effects. In contrast, the heating efficiency with the re-entering effects in the counter injection of the NBI (ctr-NBI case) rarely differs from that without the re-entering ones. We also study the re-entering fast ion effects on the transport properties in the LHD high beta discharges. It is found that the tendency of the thermal conductivities on the beta value is not so much sensitive with and without the re-entering effects. In addition, we investigate the difference in the re-entering fast ion effects caused by the field strength and the magnetic configuration. In the co-NBI case, the re-entering fast ion effects on the heating efficiency increases with the decrease of the field strength. In the contrast, the re-entering fast ion effects in the ctr-NBI case rarely differs by changing the field strength. (author)

  2. Fast ion loss and radial electric field in Wendelstein VII-Λ stellarator

    International Nuclear Information System (INIS)

    Itoh, K.; Sanuki, H.; Itoh, S.

    1991-10-01

    Theoretical model is developed to determine the radial electric field and the fast ion loss simultaneously in stellarators, and is applied to the Wendelstein VII-A stellarator. The predicted value of the radial electric field is more closer to experiments than the purely neoclassical calculation. The loss rate, which is determined simultaneously, is in the range of experimental observations. The partition of the injection energy by the bulk heating, direct orbit loss and shine through is estimated by using the self consistent electric field profile. The orbit loss become noticeable as the injection energy increases. The influence of the neutral particles is also studied. Neutral particles enhances the negative radial electric field, and reduces the direct orbit loss by the expense of the charge exchange loss. The impact of the increased radial electric field on the neoclassical ion thermal energy loss is compared to the direct loss of fast ions. The reduction of the neoclassical loss is much smaller than the orbit loss. (author)

  3. Update on fast ion instability simulations for the CLIC main linac

    CERN Document Server

    Rumolo, G

    2010-01-01

    The specification for vacuum pressure in the CLIC electron Main Linac critically depends on the fast ion instability. In fact, the maximum tolerable pressure value in the pipe of the Main Linac is dictated by the threshold above which the fast ion instability sets in over a CLIC bunch train. Previous calculation based on ion generation from scattering ionization of the residual gas alone showed that, due to the loss of the trapping along the linac caused by the beam size shrinking from acceleration, a pressure as high as 10 nTorr could be accepted, higher than the tolerable value in the long transfer line. However, since the accelerated beam becomes transversely very small, its electric field can reach values above the field ionization threshold. When this happens, the whole space region with a sufficiently high electric field gets instantly fully ionized by the first bunch and the effect on the bunch train could be severe. We have modeled field ionization in our simulation code FASTION and re-evaluated the o...

  4. Relation between the swelling and the disordering in ionic crystals irradiated by fast heavy ions

    International Nuclear Information System (INIS)

    Boccanfuso, M.

    2001-12-01

    When fast heavy ions penetrate in matter, they slow down essentially by depositing their energy on the electrons. This can lead to strong electronic excitation densities in the solid and then to structural modifications. In this work, calcium fluoride (CaF 2 ) was used to look further into the damage induced by irradiation with fast heavy ions in ionic crystals. Four techniques were mainly employed to characterise this damage. These techniques of analysis are wide angle X-ray diffraction, surface profilometry, Rutherford backscattering spectrometry and UV-visible optical absorption spectroscopy. The results of this work show that CaF 2 answers in a multiple way to the electronic excitations. For stopping powers higher than approximately 5 keV/nm, a polygonization seems to occur. This causes a structural disorder, a swelling of 0.27 % and the formation of fractures in the material. A second damage mechanism is caused above approximately 13 keV/nm and results in a loss of the initial crystalline structure. However, optical centres appear whatever the ion stopping power, which indicates that these defects cannot be the cause of the two above mentioned damage mechanisms. According to a thermal spike model, the two thresholds can be linked to melting and sublimation energy of the material, respectively. (author)

  5. Fast Thermal Runaway Detection for Lithium-Ion Cells in Large Scale Traction Batteries

    Directory of Open Access Journals (Sweden)

    Sascha Koch

    2018-03-01

    Full Text Available Thermal runaway of single cells within a large scale lithium-ion battery is a well-known risk that can lead to critical situations if no counter measures are taken in today’s lithium-ion traction batteries for battery electric vehicles (BEVs, plug-in hybrid electric vehicles (PHEV and hybrid electric vehicles (HEVs. The United Nations have published a draft global technical regulation on electric vehicle safety (GTR EVS describing a safety feature to warn passengers in case of a thermal runaway. Fast and reliable detection of faulty cells undergoing thermal runaway within the lithium-ion battery is therefore a key factor in battery designs for comprehensive passenger safety. A set of various possible sensors has been chosen based on the determined cell thermal runaway impact. These sensors have been tested in different sized battery setups and compared with respect to their ability of fast and reliable thermal runaway detection and their feasibility for traction batteries.

  6. New experiments in organic, fast-atom-bomdardment, and secondary-ion mass spectrometry

    International Nuclear Information System (INIS)

    DiDonato, G.C.

    1987-01-01

    The goal of research presented in this dissertation is the creative use of new ionization and instrumental techniques in mass spectrometry. This goal manifests itself in three areas of mass spectrometry. In the first portion, modern, state-of-the-art instrumentation and new experiments were used to re-examine the mass spectra of transition-metal acetates and acetylacetonates. High resolution, chemical ionization, negative chemical ionization, and extended-mass-range mass spectrometry uncovered a wealth of new gas-phase ionic species. Energy-resolved mass spectrometry/mass spectrometry was applied to the characterization of molecular and fragment ion first-row transition-metal acetylacetonates, and comprises the second portion of the thesis. Studies in fast-atom-bombardment mass spectrometry are the subject of the third portion of the dissertation. Since fast-atom bombardment samples a liquid matrix, absolute and relative abundances of sputtered secondary ions are influenced by solution chemistry. The design and construction of an imaging secondary-ion mass spectrometer is the subject of the final portion of the thesis. This instrument provides for direct mass-spectrometric analysis of thin-layer and paper chromatograms and electrophoretograms

  7. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael Thomas

    2014-07-11

    Thermonuclear fusion is the energy conversion process which keeps the sun shining. For the last six decades, researchers have been investigating the physics involved in order to enable the usage of this energy supply on Earth. The most promising candidates for fusion power plants are based on magnetic confinement of plasma to provide the ideal conditions for efficient thermonuclear fusion in well controlled surroundings. One important aspect is the control of instabilities that occur in the edge region of the plasma and lead to an ejection of huge amounts of energy. Magnetic perturbation fields which are resonant in the plasma edge are found to modify the plasma favourably and reduce the impact of these instabilities. This dissertation focuses on the effects of resonant magnetic perturbation fields on the ejected energy as well as on the drawbacks of these perturbation fields. The transient energy ejection which is triggered by the instabilities causes extreme heat loads on the wall components in fusion devices. Therefore, it is crucial to understand how resonant magnetic perturbation fields affect the heat load deposition. Furthermore, the impact of resonant magnetic perturbation fields on the confinement of fast ions is an important aspect as fast ions are still required to be well confined in order to avoid additional wall loads and increase the fusion efficiency. Recent upgrades on the Joint European Torus allow for a detailed study of the heat load deposition profiles caused by transient events. Throughout this work, the new features are used for the study of the modifications of the transient heat load depositions that occur if resonant magnetic perturbation fields are applied. This leads to a further understanding of the processes involved during the plasma edge instabilities. Additionally, an alternative method using lower hybrid waves for applying resonant magnetic perturbations is investigated. Furthermore, a new diagnostic, capable of detecting fast ion

  8. Turbulent transport stabilization by ICRH minority fast ions in low rotating JET ILW L-mode plasmas

    Science.gov (United States)

    Bonanomi, N.; Mantica, P.; Di Siena, A.; Delabie, E.; Giroud, C.; Johnson, T.; Lerche, E.; Menmuir, S.; Tsalas, M.; Van Eester, D.; Contributors, JET

    2018-05-01

    The first experimental demonstration that fast ion induced stabilization of thermal turbulent transport takes place also at low values of plasma toroidal rotation has been obtained in JET ILW (ITER-like wall) L-mode plasmas with high (3He)-D ICRH (ion cyclotron resonance heating) power. A reduction of the gyro-Bohm normalized ion heat flux and higher values of the normalized ion temperature gradient have been observed at high ICRH power and low NBI (neutral beam injection) power and plasma rotation. Gyrokinetic simulations indicate that ITG (ion temperature gradient) turbulence stabilization induced by the presence of high-energetic 3He ions is the key mechanism in order to explain the experimental observations. Two main mechanisms have been identified to be responsible for the turbulence stabilization: a linear electrostatic wave-fast particle resonance mechanism and a nonlinear electromagnetic mechanism. The dependence of the stabilization on the 3He distribution function has also been studied.

  9. Electrostatic instabilities, turbulence and fast ion interactions in the TORPEX device

    International Nuclear Information System (INIS)

    Fasoli, A; Burckel, A; Federspiel, L; Furno, I; Gustafson, K; Iraji, D; Labit, B; Loizu, J; Plyushchev, G; Ricci, P; Theiler, C; Diallo, A; Podesta, M; Mueller, S H; Poli, F

    2010-01-01

    Electrostatic turbulence, related structures and their effect on particle, heat and toroidal momentum transport are investigated in TORPEX simple magnetized plasmas using high-resolution diagnostics, control parameters, linear fluid models and nonlinear numerical simulations. The nature of the dominant instabilities is controlled by the value of the vertical magnetic field, B v , relative to that of the toroidal field, B T . For B v /B T > 3%, only ideal interchange instabilities are observed. A critical pressure gradient to drive the interchange instability is experimentally identified. Interchange modes give rise to blobs, radially propagating filaments of enhanced plasma pressure. Blob velocities and sizes are obtained from electrostatic probe measurements using pattern recognition methods. The observed values span a wide range and are described by a single analytical expression, from the small blob size regime in which the blob velocity is limited by cross-field ion polarization currents, to the large blob size regime in which the limitation to the blob velocity comes from parallel currents to the sheath. As a first attempt at controlling the blob dynamical properties, limiter configurations with varying angles between field lines and the conducting surface of the limiter are explored. Mach probe measurements clearly demonstrate a link between toroidal flows and blobs. To complement probe data, a fast framing camera and a movable gas puffing system are installed. Density and light fluctuations show similar signatures of interchange activity. Further developments of optical diagnostics, including an image intensifier and laser-induced fluorescence, are under way. The effect of interchange turbulence on fast ion phase space dynamics is studied using movable fast ion source and detector in scenarios for which the development from linear waves into blobs is fully characterized. A theory validation project is conducted in parallel with TORPEX experiments, based on

  10. Light ions cyclotron bombardment to simulate fast neutron radiation damage in nuclear materials

    International Nuclear Information System (INIS)

    Segura, E.; Lucki, G.; Aguiar, D.

    1984-01-01

    The applicability and limitations of the use of cyclotron light ions bombardment to simulate the effects of the neutron irradiation are presented. Light ions with energies of about 10 MeV are capable to produce homogeneous damage in specimens suitable for measuring bulk mechanical properties although their low damage rate of 10 -5 dpa.sec -1 limit the dose range to a few dpa. On the other hand, cyclotron alpha particle implantation provides a fast and convenient way of introducing helium with a minimum of side effects so that we can take advantage of this technique to get better understanding of the mechanism by which this insoluble gas produces high temperature embrittlement. Some experimental details such as dimensions and cooling techniques are described. Finally a description of the infrastructure for cyclotron alpha particle implantation and a creep-test facility of the Division of Radiation Damage at IPEN-CNEN/SP are presented. (Author) [pt

  11. Coulomb Lindhard approximation: Nonlinear excitation effects for fast ions penetrating a free-electron gas

    International Nuclear Information System (INIS)

    Miraglia, J. E.

    2003-01-01

    We introduce a distorted wave method to calculate the nonlinear excitation effects occurring when a fast bare ion penetrates a free-electron gas. The central scheme of this work is to replace the undistorted plane waves leading to the Lindhard dielectric response function (or random phase approximation) by Coulomb waves with an effective charge. This impulse-type approximation is valid for velocities larger than the Fermi velocity. Stopping and mean free path are presented for impact of bare multicharged ions on aluminum free-electron gas. The Barkas effect is theoretically found, i.e., negative heavy particles lose energy at the lower rate than positive particles of the same velocity do. As the projectile charge increases, the single differential cross section per unit energy presents two effects: the plasmon peak sharpens and the binary peak starts to be increasingly noticeable

  12. Fast Heavy Ion Collisions with H2 Molecules And Young Type Interference

    Science.gov (United States)

    Tribedi, Lokesh C.; Misra, Deepankar

    2007-12-01

    We have investigated the Young type interference effect in electron emission spectrum from molecular H2 in Coulomb ionization induced by fast heavy ions. The details of the derivation of the oscillations due to this process from the electron double differential distributions are discussed. In addition, we have explored the effect of Compton profile, on such interference oscillations, which gives rise a double-peak structure in case of low energy collisions for which the binary encounter peak starts overlapping with soft collision electrons. The measured DDCS as well as the interference patterns are compared with molecular CDW-EIS models.

  13. Quasielastic Diffuse Neutron Scattering from Fluorites in the Fast Ion Phase

    DEFF Research Database (Denmark)

    Clausen, K.; Hayes, W.; Hutchings, M.T

    1981-01-01

    Quasielastic diffuse coherent neutron scattering arising from the dynamically disordered anions in CaF2 and PbF2 has been investigated as the temperature is increased into the fast ion phase. The characteristic variation with scattering vector Image of the integrated intensity, S(Image ), can...... be accounted for by a model in which the most probable instantaneous configuration of the defective anions is a cluster centered at the mid-point of nearest-neighbour regular anion sites. The observed S(Image ,ω) is Lorentzian in ω and the width has a marked increase with temperature....

  14. ITER fast ion collective Thomson scattering. Conceptual design of 60 GHz system

    DEFF Research Database (Denmark)

    Meo, Fernando; Bindslev, Henrik; Korsholm, Søren Bang

    The collective Thomson scattering diagnostic for ITER at the 60 GHz range is capable of measuring the fast ion distribution parallel and perpendicular to the magnetic field at different radial locations simultaneously. The design is robust technologically with no moveable components near the plasma...... describes the two systems and their main components. Section 3 clarifies the impact of design parameters such as beam widths and scattering angle on the CTS measurements. With this in hand, the ITER measurement requirements are translated into constraints on the CTS system designs. An important result...

  15. Fast ion collective Thomson scattering - present results and plans for ITER

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran

    by the CTS group at Risø DTU building on the experiences and expertise gained from the group’s construction and current operation of the CTS diagnostic systems on the tokamaks TEXTOR and ASDEX Upgrade. This contribution will introduce the technique of CTS, give an overview of the current diagnostic systems......Moving towards the era of burning fusion plasmas, a better knowledge of the physics of highly energetic particles, such as the 3.5 MeV fusion born alpha particles, becomes necessary. Diagnosing the fast ions in a fusion plasma is a challenging task, but the technique of collective Thomson...

  16. Fast detection of narcotics by single photon ionization mass spectrometry and laser ion mobility spectrometry

    Science.gov (United States)

    Laudien, Robert; Schultze, Rainer; Wieser, Jochen

    2010-10-01

    In this contribution two analytical devices for the fast detection of security-relevant substances like narcotics and explosives are presented. One system is based on an ion trap mass spectrometer (ITMS) with single photon ionization (SPI). This soft ionization technique, unlike electron impact ionization (EI), reduces unwanted fragment ions in the mass spectra allowing the clear determination of characteristic (usually molecular) ions. Their enrichment in the ion trap and identification by tandem MS investigations (MS/MS) enables the detection of the target substances in complex matrices at low concentrations without time-consuming sample preparation. For SPI an electron beam pumped excimer light source of own fabrication (E-Lux) is used. The SPI-ITMS system was characterized by the analytical study of different drugs like cannabis, heroin, cocaine, amphetamines, and some precursors. Additionally, it was successfully tested on-site in a closed illegal drug laboratory, where low quantities of MDMA could be directly detected in samples from floors, walls and lab equipments. The second analytical system is based on an ion mobility (IM) spectrometer with resonant multiphoton ionization (REMPI). With the frequency quadrupled Nd:YAG laser (266 nm), used for ionization, a selective and sensitive detection of aromatic compounds is possible. By application of suited aromatic dopants, in addition, also non-aromatic polar compounds are accessible by ion molecule reactions like proton transfer or complex formation. Selected drug precursors could be successfully detected with this device as well, qualifying it to a lower-priced alternative or useful supplement of the SPI-ITMS system for security analysis.

  17. Benchmark and combined velocity-space tomography of fast-ion D-alpha spectroscopy and collective Thomson scattering measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko; Geiger, B.

    2016-01-01

    measurements without using a numerical simulation as common reference. Combined velocity-space tomographies from FIDA and CTS measurements confirm that sawtooth crashes reduce the fast-ion phase-space densities in the plasma center and affect ions with pitches close to one more strongly than those with pitches......We demonstrate the combination of fast-ion D-alpha spectroscopy (FIDA) and collective Thomson scattering (CTS) measurements to determine a common best estimate of the fastion velocity distribution function by velocity-space tomography. We further demonstrate a benchmark of FIDA tomography and CTS...

  18. Coherent structures at ion scales in fast and slow solar wind: Cluster observations

    Science.gov (United States)

    Perrone, D.; Alexandrova, O.; Zouganelis, Y.; Roberts, O.; Lion, S.; Escoubet, C. P.; Walsh, A. P.; Maksimovic, M.; Lacombe, C.

    2017-12-01

    Spacecraft measurements generally reveal that solar wind electromagnetic fluctuations are in a state of fully-developed turbulence. Turbulence represents a very complex problem in plasmas since cross-scale coupling and kinetic effects are present. Moreover, the intermittency phenomenon, i.e. the manifestation of the non-uniform and inhomogeneous energy transfer and dissipation in a turbulent system, represents a very important aspect of the solar wind turbulent cascade. Here, we study coherent structures responsible for solar wind intermittency around ion characteristic scales. We find that, in fast solar wind, intermittency is due to Alfvén vortex-like structures and current sheets. In slow solar wind, we observe as well compressive structures like magnetic solitons, holes and shocks. By using high-time resolution magnetic field data of multi-point measurements of Cluster spacecraft, we characterize the observed coherent structures in terms of topology and propagation speed. We show that all structures around ion characteristic scales, both in fast and slow solar wind, are characterized by a strong wave-vector anisotropy in the perpendicular direction with respect to the local magnetic field. Moreover, some of them propagate in the plasma rest frame in the direction perpendicular to the local field. Finally, a further analysis on the electron and ion velocity distributions shows a high variability; in particular, close to coherent structures the electron and ion distribution functions appear strongly deformed and far from the thermodynamic equilibrium. Possible interpretations of the observed structures and their role in the heating process of the plasma are also discussed.

  19. The practical model of electron emission in the radioisotope battery by fast ions

    International Nuclear Information System (INIS)

    Erokhine, N.S.; Balebanov, V.M.

    2003-01-01

    Under the theoretical analysis of secondary-emission radioisotope source of current the estimate of energy spectrum F(E) of secondary electrons with energy E emitted from films is the important problem. This characteristic knowledge allows, in particular, studying the volt-ampere function, the dependence of electric power deposited in the load on the system parameters and so on. Since the rigorous calculations of energy spectrum F(E) are the complicated enough and labour-intensive there is necessity to elaborate the practical model which allows by the simple computer routine on the basis of generalized data (both experimental measurements and theoretical calculations) on the stopping powers and mean free path of suprathermal electrons to perform reliable express-estimates of the energy spectrum F(E) and the volt-ampere function I(V) for the concrete materials of battery emitter films. This paper devoted to description of of the practical model to calculate electron emission characteristics under the passage of fast ion fluxes from the radioisotope source through the battery emitter. The analytical approximations for the stopping power of emitter materials, the electron inelastic mean free path, the ion production of fast electrons and the probability for them to arrive the film surface are taken into account. In the cases of copper and gold films, the secondary electron escaping depth, the position of energy spectrum peak are considered in the dependence on surface potential barrier magnitude U. According to our calculations the energy spectrum peak shifted to higher electron energy under the U growth. The model described may be used for express estimates and computer simulations of fast alpha-particles and suprathermal electrons interactions with the solid state plasma of battery emitter films, to study the electron emission layer characteristics including the secondary electron escaping depth, to find the optimum conditions for excitation of nonequilibrium

  20. Development of sputter ion pump based SG leak detection system for Fast Breeder Test Reactor

    International Nuclear Information System (INIS)

    Babu, B.; Sureshkumar, K.V.; Srinivasan, G.

    2013-01-01

    Highlights: ► Development and commissioning of SG leak detection system for FBTR. ► Development of Robust method of using sputter ion pump based system. ► Modifications for improving reliability and availability. ► On line injection of hydrogen in sodium during reactor operation. ► Triplication of the SG leak detection system. - Abstract: The Fast Breeder Test Reactor (FBTR) is a 40 MWt, loop type sodium cooled fast reactor built at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam as a fore-runner to the second stage of Indian nuclear power programme. The reactor design is based on the French reactor Rapsodie with several modifications which include the provision of a steam-water circuit and turbo-generator. FBTR uses sodium as the coolant in the main heat transport medium to transfer heat from the reactor core to the feed water in the tertiary loop for producing superheated steam, which drives the turbo-generator. Sodium and water flow in shell and tube side respectively, separated by thin-walls of the ferritic steel tubes of the once-through steam generator (SG). Material defects in these tubes can lead to leakage of water into sodium, resulting in sodium water reactions leading to undesirable consequences. Early detection of water or steam leaks into sodium in the steam generator units of liquid metal fast breeder reactors (LMFBR) is an important requirement from safety and economic considerations. The SG leak in FBTR is detected by Sputter Ion Pump (SIP) based Steam Generator Leak Detection (SGLD) system and Thermal Conductivity Detector (TCD) based Hydrogen in Argon Detection (HAD) system. Many modifications were carried out in the SGLD system for the reactor operation to improve the reliability and availability. This paper details the development and the acquired experience of SIP based SGLD system instrumentation for real time hydrogen detection in sodium for FBTR.

  1. Particle-in-cell studies of fast-ion slowing-down rates in cool tenuous magnetized plasma

    Science.gov (United States)

    Evans, Eugene S.; Cohen, Samuel A.; Welch, Dale R.

    2018-04-01

    We report on 3D-3V particle-in-cell simulations of fast-ion energy-loss rates in a cold, weakly-magnetized, weakly-coupled plasma where the electron gyroradius, ρe, is comparable to or less than the Debye length, λDe, and the fast-ion velocity exceeds the electron thermal velocity, a regime in which the electron response may be impeded. These simulations use explicit algorithms, spatially resolve ρe and λDe, and temporally resolve the electron cyclotron and plasma frequencies. For mono-energetic dilute fast ions with isotropic velocity distributions, these scaling studies of the slowing-down time, τs, versus fast-ion charge are in agreement with unmagnetized slowing-down theory; with an applied magnetic field, no consistent anisotropy between τs in the cross-field and field-parallel directions could be resolved. Scaling the fast-ion charge is confirmed as a viable way to reduce the required computational time for each simulation. The implications of these slowing down processes are described for one magnetic-confinement fusion concept, the small, advanced-fuel, field-reversed configuration device.

  2. Characterization of scintillator materials for fast-ion loss detectors in nuclear fusion reactors

    Science.gov (United States)

    Jiménez-Ramos, M. C.; García López, J.; García-Muñoz, M.; Rodríguez-Ramos, M.; Carmona Gázquez, M.; Zurro, B.

    2014-08-01

    In fusion plasma reactors, fast ion generated by heating systems and fusion born particles must be well confined. The presence of magnetohydrodynamic (MHD) instabilities can lead to a significant loss of these ions, which may reduce drastically the heating efficiency and may cause damage to plasma facing components in the vacuum vessel. In order to understand the physics underlying the fast ion loss mechanism, scintillator based detectors have been installed in several fusion devices. In this work we present the absolute photon yield and its degradation with ion fluence in terms of the number of photons emitted per incident ion of several scintillators thin coatings: SrGa2S4:Eu2+ (TG-Green), Y3Al5O12:Ce3+ (P46) and Y2O3:Eu3+ (P56) when irradiated with light ions of different masses (deuterium ions, protons and α-particles) at energies between approximately 575 keV and 3 MeV. The photon yield will be discussed in terms of the energy deposited by the particles into the scintillator. For that, the actual composition and thickness of the thin layers were determined by Rutherford Backscattering Spectrometry (RBS). A collimator with 1 mm of diameter, which defines the beam size for the experiments, placed at the entrance of the chamber. An electrically isolated sample holder biased to +300 V to collect the secondary electrons, connected to a digital current integrator (model 439 by Ortec) to measure the incident beam current. A home made device has been used to store the real-time evolution of the beam current in a computer file allowing the correction of the IL yields due to the current fluctuations. The target holder is a rectangle of 150 × 112 mm2 and can be tilted. The X and Y movements are controlled through stepping motors, which permits a fine control of the beam spot positioning as well as the study of several samples without venting the chamber. A silica optical fiber of 1 mm diameter fixed to the vacuum chamber, which collects the light from the scintillators

  3. Removing coordinated metal ions from proteins: a fast and mild method in aqueous solution.

    Science.gov (United States)

    Carrer, Charlotte; Stolz, Michael; Lewitzki, Erwin; Rittmeyer, Claudia; Kolbesen, Bernd O; Grell, Ernst

    2006-08-01

    Thermodynamic and kinetic studies of metal binding to proteins require the investigation of metal-free proteins, which are often difficult to obtain. We have developed a very fast and mild method to eliminate metal ions from proteins by column chromatography using a commercially available Ni-NTA-type stationary phase. This material, initially designed for protein purification purposes in biotechnology, acts as a strong cation chelator when Ni2+ ions are removed. We have tested this new method with Ca-ATPase, an integral membrane protein exhibiting a strong affinity for Ca2+. By eluting the protein over the Ni2+-free NTA gel, we could remove 95% of the total Ca2+ and obtain an essentially Ca2+-free protein. This method is efficient with only a small amount of NTA gel, and we suggest that it can be applied in general for removal of metal ions from proteins. Moreover, as this procedure can be carried out under mild conditions, the chosen protein kept its enzymatic activity.

  4. Study of the Mechanism for Fast Ion Heating in the GOL-3 Multimirror Magnetic Confinement System

    International Nuclear Information System (INIS)

    Arzhannikov, A.V.; Astrelin, V.T.; Burdakov, A.V.; Ivanov, I.A.; Koidan, V.S.; Kuznetsov, S.A.; Mekler, K.I.; Polosatkin, S.V.; Postupaev, V.V.; Rovenskikh, A.F.; Sinitskii, S.L.; Sulyaev, Yu.S.; Shoshin, A.A.

    2005-01-01

    Results are presented from experimental studies of ion heating in the GOL-3 device. The experiments were carried out in a multimirror configuration with a local magnetic well. It was found that, during the injection of a relativistic electron beam, a decrease in the local density of the beam in a magnetic well, which is proportional to the decrease in the strength of the longitudinal magnetic field, results in the formation of a short plasma region with a low electron temperature. The measured longitudinal gradient of the plasma pressure corresponds to an electron temperature gradient of ∼2-3 keV/m. Axially nonuniform heating of the plasma electrons gives rise to the macroscopic motion of the plasma along the magnetic field in each cell of the multimirror confinement system. The mixing of the counterpropagating plasma flows inside each cell leads to fast ion heating. Under the given experimental conditions, the efficiency of this heating mechanism is higher than that due to binary electron-ion collisions. The collision and mixing of the counterpropagating plasma flows is accompanied by a neutron and γ-ray burst. The measured ratio of the plasma pressure to the vacuum magnetic field pressure in these experiments reaches 0.2

  5. Fast Beam-ion Instabilities in CLIC Main Linac Vacuum Specifications

    CERN Document Server

    Oeftiger, Adrian

    2011-01-01

    Specifications for the vacuum pressure in the CLIC electron Main Linac are determined by the onset of the fast beam-ion instability (FBII). When the electron beam is accelerated in the Main Linac, it ionizes the residual gas in the chamber through scattering ionization. If the density of ions around the beam exceeds a certain threshold, a resonant motion between the electron beam and the ions can be excited. A two-stream instability appears and as a result the beam acquires a coherent motion, which can quickly lead to beam quality degradation or even complete loss. Thus, the vacuum pressure must be kept below this threshold to prevent the excitation of FBII. The CLIC Main Linac poses an additional challenge with respect to previous FBII situations, because the gas ionization does not solely occur via scattering. The submicrometric beam sizes lead to extremely high electric fields around the beam and therefore result in field ionization beyond a certain threshold. The residual gas in the corresponding volume a...

  6. 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

  7. Catapult mechanism for fast particle emission in fission and heavy ion reactions

    International Nuclear Information System (INIS)

    Maedler, P.

    1984-01-01

    The fission processes of slabs of nuclear matter is modelled in the Hartree-Fock time dependence approximation by adding an initial collective velocity field to the static self-consistent solution. In dependence on its amplitude either large amplitude density oscillations are excited or fission occurs. The final disintegration of the slab proceeds on a time scale 10 -22 s and is characterized by a sharp peak in the actual velocity field in the region of the ''snatching'' inner low density tails. A characteristic time later a low density lump correlated with a peak in the velocity field energies in front of the fragments. These particles are called ''catapult particles''. Recent experimental results possibly provide evidence for catapult neutrons in low-energy fission. The significance of the catapult mechanism for fast particle emission in the exit channel of heavy ion reactions is discussed

  8. Behaviour of direct and delayed fast ion losses during NBI on TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.; Liniers; M.

    1995-09-01

    The dependence with density and beam energy of the different kind of fast ion losses, direct and delayed, during tangential balanced NBI injection in TJ-II helical axis stellerator has been analysed. Direct losses increase with energy and a strong difference between the two injection directions appears, are produced by passing particles that loss confinement in a dew mu,sec and the influence of birth profiles produces an increase with density. Delayed losses are very well separated in time from direct ones, are produced by particles experimenting pitch angle scattering an,d, most o them, correspond to trapped particles. Are much less important than the direct ones (about 1/3), decrease slowly with energy and, with CX, increase with density (an effect of initial profile). The absorption is rather independent of energy with low values at low density in reason of high shine trough and CX losses, but reovers quickly with the density increase

  9. Impacts of lost fast ions on the TJ-II Vacuum Vessel during NBI

    International Nuclear Information System (INIS)

    Guasp, J.

    1995-01-01

    The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed. (Author) 6 refs

  10. Impacts of lost fast ions on the TJ-II Vacuum vessel during NBI

    International Nuclear Information System (INIS)

    Guasp, J.

    1995-09-01

    The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed

  11. Neutron spectroscopy measurements and modeling of neutral beam heating fast ion dynamics

    International Nuclear Information System (INIS)

    Hellesen, C; Sunden, E Andersson; Conroy, S; Ericsson, G; Johnson, M Gatu; Hjalmarsson, A; Kaellne, J; Ronchi, E; Sjoestrand, H; Weiszflog, M; Albergante, M; Ballabio, L; Gorini, G; Tardocchi, M; Giacomelli, L; Jenkins, I; Voitsekhovitch, I

    2010-01-01

    The energy spectrum of the neutron emission from beam-target reactions in fusion plasmas at the Joint European Torus (JET) has been investigated. Different beam energies as well as injection angles were used. Both measurements and simulations of the energy spectrum were done. The measurements were made with the time-of-flight spectrometer TOFOR. Simulations of the neutron spectrum were based on first-principle calculations of neutral beam deposition profiles and the fast ion slowing down in the plasma using the code NUBEAM, which is a module of the TRANSP package. The shape of the neutron energy spectrum was seen to vary significantly depending on the energy of the beams as well as the injection angle and the deposition profile in the plasma. Cross validations of the measured and modeled neutron energy spectra were made, showing a good agreement for all investigated scenarios.

  12. Randomized quasi-Monte Carlo simulation of fast-ion thermalization

    International Nuclear Information System (INIS)

    Höök, L J; Johnson, T; Hellsten, T

    2012-01-01

    This work investigates the applicability of the randomized quasi-Monte Carlo method for simulation of fast-ion thermalization processes in fusion plasmas, e.g. for simulation of neutral beam injection and radio frequency heating. In contrast to the standard Monte Carlo method, the quasi-Monte Carlo method uses deterministic numbers instead of pseudo-random numbers and has a statistical weak convergence close to O(N -1 ), where N is the number of markers. We have compared different quasi-Monte Carlo methods for a neutral beam injection scenario, which is solved by many realizations of the associated stochastic differential equation, discretized with the Euler-Maruyama scheme. The statistical convergence of the methods is measured for time steps up to 2 14 . (paper)

  13. Randomized quasi-Monte Carlo simulation of fast-ion thermalization

    Science.gov (United States)

    Höök, L. J.; Johnson, T.; Hellsten, T.

    2012-01-01

    This work investigates the applicability of the randomized quasi-Monte Carlo method for simulation of fast-ion thermalization processes in fusion plasmas, e.g. for simulation of neutral beam injection and radio frequency heating. In contrast to the standard Monte Carlo method, the quasi-Monte Carlo method uses deterministic numbers instead of pseudo-random numbers and has a statistical weak convergence close to {O}(N^{-1}) , where N is the number of markers. We have compared different quasi-Monte Carlo methods for a neutral beam injection scenario, which is solved by many realizations of the associated stochastic differential equation, discretized with the Euler-Maruyama scheme. The statistical convergence of the methods is measured for time steps up to 214.

  14. Interaction of powerful hot plasma and fast ion streams with materials in dense plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Gribkov, V.A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Kowalska-Strzeciwilk, E.; Kubkowska, M.; Miklaszewski, R.; Paduch, M.; Pisarczyk, T.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Demina, E.V.; Pimenov, V.N.; Maslyaev, S.A. [Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Bondarenko, G.G. [National Research University Higher School of Economics (HSE), Moscow (Russian Federation); Vilemova, M.; Matejicek, J. [Institute of Plasma Physics of the CAS, Prague (Czech Republic)

    2016-12-15

    Highlights: • Materials perspective for use in mainstream nuclear fusion facilities were studied. • Powerful streams of hot plasma and fast ions were used to induce irradiation. • High temporal, spatial, angular and spectral resolution available in experiments. • Results of irradiation were investigated by number of analysis techniques. - Abstract: A process of irradiating and ablating solid-state targets with hot plasma and fast ion streams in two Dense Plasma Focus (DPF) devices – PF-6 and PF-1000 was examined by applying a number of diagnostics of nanosecond time resolution. Materials perspective for use in chambers of the mainstream nuclear fusion facilities (mainly with inertial plasma confinement like NIF and Z-machine), intended both for the first wall and for constructions, have been irradiated in these simulators. Optical microscopy, SEM, Atomic Emission Spectroscopy, images in secondary electrons and in characteristic X-ray luminescence of different elements, and X-ray elemental analysis, gave results on damageability for a number of materials including low-activated ferritic and austenitic stainless steels, β-alloy of Ti, as well as two types of W and a composite on its base. With an increase of the number of shots irradiating the surface, its morphology changes from weakly pronounced wave-like structures or ridges to strongly developed ones. At later stages, due to the action of the secondary plasma produced near the target materials they melted, yielding both blisters and a fracturing pattern: first along the grain and then “in-between” the grains creating an intergranular net of microcracks. At the highest values of power flux densities multiple bubbles appeared. Furthermore, in this last case the cracks were developed because of microstresses at the solidification of melt. Presence of deuterium within the irradiated ferritic steel surface nanolayers is explained by capture of deuterons in lattice defects of the types of impurity atoms

  15. Feature-based plan adaptation for fast treatment planning in scanned ion beam therapy

    International Nuclear Information System (INIS)

    Chen Wenjing; Gemmel, Alexander; Rietzel, Eike

    2013-01-01

    We propose a plan adaptation method for fast treatment plan generation in scanned ion beam therapy. Analysis of optimized treatment plans with carbon ions indicates that the particle number modulation of consecutive rasterspots in depth shows little variation throughout target volumes with convex shape. Thus, we extract a depth-modulation curve (DMC) from existing reference plans and adapt it for creation of new plans in similar treatment situations. The proposed method is tested with seven CT serials of prostate patients and three digital phantom datasets generated with the MATLAB code. Plans are generated with a treatment planning software developed by GSI using single-field uniform dose optimization for all the CT datasets to serve as reference plans and ‘gold standard’. The adapted plans are generated based on the DMC derived from the reference plans of the same patient (intra-patient), different patient (inter-patient) and phantoms (phantom-patient). They are compared with the reference plans and a re-positioning strategy. Generally, in 1 min on a standard PC, either a physical plan or a biological plan can be generated with the adaptive method provided that the new target contour is available. In all the cases, the V95 values of the adapted plans can achieve 97% for either physical or biological plans. V107 is always 0 indicating no overdosage, and target dose homogeneity is above 0.98 in all cases. The dose received by the organs at risk is comparable to the optimized plans. The plan adaptation method has the potential for on-line adaptation to deal with inter-fractional motion, as well as fast off-line treatment planning, with either the prescribed physical dose or the RBE-weighted dose. (paper)

  16. FAST

    DEFF Research Database (Denmark)

    Zuidmeer-Jongejan, Laurian; Fernandez-Rivas, Montserrat; Poulsen, Lars K.

    2012-01-01

    ABSTRACT: The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections...... with aqueous food extracts may be effective but has proven to be accompanied by too many anaphylactic side-effects. FAST aims to develop a safe alternative by replacing food extracts with hypoallergenic recombinant major allergens as the active ingredients of SIT. Both severe fish and peach allergy are caused...... in depth serological and cellular immune analyses will be performed, allowing identification of novel biomarkers for monitoring treatment efficacy. FAST aims at improving the quality of life of food allergic patients by providing a safe and effective treatment that will significantly lower their threshold...

  17. On the fast electron beam, consequent generation of electrostatic fields and fast ion production in front of LH grills: Measurements and theory

    International Nuclear Information System (INIS)

    Petrzilka, V.; Zacek, F.; Kolman, B.

    2001-01-01

    The paper presents measurements of radial variations of the floating potential at the Tore Supra (TS) tokamak ergodic divertor plate and in front of the CASTOR tokamak lower hybrid (LH) grill, due to the presence in these two locations of the fast particle beam generated in front of LH grills. The paper also presents a scanning electron microscope (SEM) and secondary ion mass spectrometric (SIMS) analysis of an eroded graphite tile from the TS LH grill guard limiter, performed in order to check the authors' theoretical conclusion that fast ions can be generated in a thin layer in front of LH grills and that they can contribute to damage of tokamak vessel components. The paper first presents theoretical conclusions that are relevant to the experimental data and then the experimental results. (author)

  18. A Novel Data-Driven Fast Capacity Estimation of Spent Electric Vehicle Lithium-ion Batteries

    Directory of Open Access Journals (Sweden)

    Caiping Zhang

    2014-12-01

    Full Text Available Fast capacity estimation is a key enabling technique for second-life of lithium-ion batteries due to the hard work involved in determining the capacity of a large number of used electric vehicle (EV batteries. This paper tries to make three contributions to the existing literature through a robust and advanced algorithm: (1 a three layer back propagation artificial neural network (BP ANN model is developed to estimate the battery capacity. The model employs internal resistance expressing the battery’s kinetics as the model input, which can realize fast capacity estimation; (2 an estimation error model is established to investigate the relationship between the robustness coefficient and regression coefficient. It is revealed that commonly used ANN capacity estimation algorithm is flawed in providing robustness of parameter measurement uncertainties; (3 the law of large numbers is used as the basis for a proposed robust estimation approach, which optimally balances the relationship between estimation accuracy and disturbance rejection. An optimal range of the threshold for robustness coefficient is also discussed and proposed. Experimental results demonstrate the efficacy and the robustness of the BP ANN model together with the proposed identification approach, which can provide an important basis for large scale applications of second-life of batteries.

  19. Experiments on the fast beam-ion instability at the ALS

    International Nuclear Information System (INIS)

    Zimmermann, F.; Chao, A.; Heifets, S.; Minty, M.; Seeman, J.; Stupakov, G.; Raubenheimer, T.

    1997-10-01

    The authors report on the first observation of the fast beam-ion instability (FBII), at the Advanced Light Source (ALS). The FBII is a novel single-pass instability, which is similar to the classical beam break up instability in a linac. Unlike the classical trapped-ion instability, the FBII cannot be cured by a clearing gap in the bunch train, and it is predicted to be a potential limitation for many multi-bunch small-emittance storage rings and linacs. In order to induce the FBII in the ALS, they added helium gas to the vacuum system so as to increase the vacuum pressure by two orders of magnitude above its normal value. At an elevated pressure of about 50--100 nTorr, the authors observed a variety of effects, including an increase of the vertical beam size by a factor 2--4, self-excited betatron sidebands, and a growth of the betatron motion along the bunch train. The onset of the vertical beam-size increase (as a function of bunch number) occurred close to the theoretically predicted instability threshold

  20. Development and testing of a fast digital electronic system for ion identification and spectroscopy

    International Nuclear Information System (INIS)

    Legou, Th.

    2002-02-01

    This report deals with a fast digital electronic system developed for ion identification and spectroscopy. The system, called IRIS, has been conceived for the super heavy element research program: FUSION. In order to observe a super heavy element, the energy of the compound nucleus implanted in a silicon detector must be measured, and the alpha decay also registered. The associated electronics must therefore handle a very wide range of energies and also exhibit a small recovery time after the implantation of the compound nucleus. IRIS is connected to the output of a charge preamplifier. It digitizes the signal and then executes two digital signal processes: the first to detect the particle, and the second to determine the energy deposited in the silicon detector. The use of programmed processing allows for the adjustment of the digital processing parameters, as well as a choice of other digital signal processing procedures, depending the application. After having explained why a conventional electronic system cannot be used for the detection of super-heavy ions, IRIS' structure is detailed and a number of digital signal processing procedures are studied and tested. (author)

  1. Isomeric signatures in the fragmentation of pyridazine and pyrimidine induced by fast ion impact

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Wania, E-mail: wania@if.ufrj.br; Luna, Hugo; Montenegro, Eduardo C. [Instituto de Física, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil)

    2015-07-28

    We present fast proton impact induced fragmentations of pyrimidine and pyridazine as an experimental resource to investigate isomeric signatures. Major isomeric imprints are identified for few fragment ions and differences of more than an order of magnitude for the cross sections of fragments of the same mass were measured. The observation of the molecular structure of these isomers gives no apparent indication for the reasons for such substantial differences. It is verified that the simple displacement of the position of one nitrogen atom strongly inhibits or favors the production of some ionic fragment species. The dependency of the fragmentation cross sections on the proton impact energy, investigated by means of time of flight mass spectroscopy and of a model calculation based in first order perturbation theory, allows us to disentangle the complex collision dynamics of the ionic fragments. The proton-induced fragmentation discriminates rather directly the association between a molecular orbital ionization and the fragment-ions creation and abundance, as well as how the redistribution of the energy imparted to the molecules takes place, triggering not only single but also double vacancy and leads to specific fragmentation pathways.

  2. Differential electron emission from polycyclic aromatic hydrocarbon molecules under fast ion impact.

    Science.gov (United States)

    Biswas, Shubhadeep; Champion, Christophe; Weck, P F; Tribedi, Lokesh C

    2017-07-17

    Interaction between polycyclic aromatic hydrocarbon (PAH) molecule and energetic ion is a subject of interest in different areas of modern physics. Here, we present measurements of energy and angular distributions of absolute double differential electron emission cross section for coronene (C 24 H 12 ) and fluorene (C 13 H 10 ) molecules under fast bare oxygen ion impact. For coronene, the angular distributions of the low energy electrons are quite different from that of simpler targets like Ne or CH 4 , which is not the case for fluorene. The behaviour of the higher electron energy distributions for both the targets are similar to that for simple targets. In case of coronene, a clear signature of plasmon resonance is observed in the analysis of forward-backward angular asymmetry of low energy electron emission. For fluorene, such signature is not identified probably due to lower oscillator strength of plasmon compared to the coronene. The theoretical calculation based on the first-order Born approximation with correct boundary conditions (CB1), in general, reproduced the experimental observations qualitatively, for both the molecules, except in the low energy region for coronene, which again indicates the role of collective excitation. Single differential and total cross sections are also deduced. An overall comparative study is presented.

  3. Radioactive Ion Beam Production by Fast-Neutron-Induced Fission in Actinide Targets at EURISOL

    CERN Document Server

    Herrera-Martínez, Adonai

    The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, the production of high-intensity RIBs of specific neutron-rich isotopes is obtained by inducing fission in large-mass actinide targets. In our contribution, the use of uranium targets is shown to be advantageous to other materials, such as thorium. Therefore, in order to produce fissions in U-238 and reduce the plutonium inventory, a fast neutron energy spectrum is necessary. The large beam power required to achieve these RIB levels requires the use of a liquid proton-to-neutron converter. This article details the design parameters of the converter, with special attention to the coupled neutronics of the liquid converter and fission target. Calculations performed with the ...

  4. Non-linear isotope and fast ions effects: routes for low turbulence in DT plasmas

    Science.gov (United States)

    Garcia, Jeronimo

    2017-10-01

    effects. The number of ion species and the fast ion population is also found to play a role in this non-linear process whereas a symmetry breaking between D and T, with systematic reduced heat and particle transport for T, is always obtained.

  5. Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

    DEFF Research Database (Denmark)

    Salewski, Mirko; Asunta, O.; Eriksson, L.-G.

    2009-01-01

    functions of fast ions generated by NBI and ICRH are calculated for a steady-state ITER burning plasma equilibrium with the ASCOT and PION codes, respectively. The parameters for the auxiliary heating systems correspond to the design currently foreseen for ITER. The geometry of the CTS system for ITER...

  6. Fast-ion transport in low density L-mode plasmas at TCV using FIDA spectroscopy and the TRANSP code

    DEFF Research Database (Denmark)

    Geiger, B.; Karpushov, A.; Duval, B. P.

    2017-01-01

     agreement between the experimental data and TRANSP predictions is only found when including strong additional fast-ion losses. These losses could in part be caused by turbulence or MHD activity as, e.g. high frequency modes near the frequency of toroidicity induced Alfvén eignmodes are observed. In addition...

  7. High-performance rechargeable batteries with nanoparticle active materials, photochemically regenerable active materials, and fast solid-state ion conductors

    Science.gov (United States)

    Farmer, Joseph C.

    2017-04-04

    A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.

  8. FAST

    Science.gov (United States)

    Nathavitharana, R R; Daru, P; Barrera, A E; Mostofa Kamal, S M; Islam, S; Ul-Alam, M; Sultana, R; Rahman, M; Hossain, Md S; Lederer, P; Hurwitz, S; Chakraborty, K; Kak, N; Tierney, D B; Nardell, E

    2017-09-01

    National Institute of Diseases of the Chest and Hospital, Dhaka; Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, Dhaka; and Chittagong Chest Disease Hospital, Chittagong, Bangladesh. To present operational data and discuss the challenges of implementing FAST (Find cases Actively, Separate safely and Treat effectively) as a tuberculosis (TB) transmission control strategy. FAST was implemented sequentially at three hospitals. Using Xpert® MTB/RIF, 733/6028 (12.2%, 95%CI 11.4-13.0) patients were diagnosed with unsuspected TB. Patients with a history of TB who were admitted with other lung diseases had more than twice the odds of being diagnosed with unsuspected TB as those with no history of TB (OR 2.6, 95%CI 2.2-3.0, P stakeholder engagement and laboratory capacity are important for sustainability and scalability.

  9. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    DEFF Research Database (Denmark)

    Nishiura, M.; Kubo, S.; Tanaka, K.

    2014-01-01

    A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron......, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1–2 ke......V for electron densities of (1–2) × 1019 m−3 and electron temperatures of 2–4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v‖, v⊥) based on Monte...

  10. Ion channel density regulates switches between regular and fast spiking in soma but not in axons.

    Directory of Open Access Journals (Sweden)

    Hugo Zeberg

    2010-04-01

    Full Text Available The threshold firing frequency of a neuron is a characterizing feature of its dynamical behaviour, in turn determining its role in the oscillatory activity of the brain. Two main types of dynamics have been identified in brain neurons. Type 1 dynamics (regular spiking shows a continuous relationship between frequency and stimulation current (f-I(stim and, thus, an arbitrarily low frequency at threshold current; Type 2 (fast spiking shows a discontinuous f-I(stim relationship and a minimum threshold frequency. In a previous study of a hippocampal neuron model, we demonstrated that its dynamics could be of both Type 1 and Type 2, depending on ion channel density. In the present study we analyse the effect of varying channel density on threshold firing frequency on two well-studied axon membranes, namely the frog myelinated axon and the squid giant axon. Moreover, we analyse the hippocampal neuron model in more detail. The models are all based on voltage-clamp studies, thus comprising experimentally measurable parameters. The choice of analysing effects of channel density modifications is due to their physiological and pharmacological relevance. We show, using bifurcation analysis, that both axon models display exclusively Type 2 dynamics, independently of ion channel density. Nevertheless, both models have a region in the channel-density plane characterized by an N-shaped steady-state current-voltage relationship (a prerequisite for Type 1 dynamics and associated with this type of dynamics in the hippocampal model. In summary, our results suggest that the hippocampal soma and the two axon membranes represent two distinct kinds of membranes; membranes with a channel-density dependent switching between Type 1 and 2 dynamics, and membranes with a channel-density independent dynamics. The difference between the two membrane types suggests functional differences, compatible with a more flexible role of the soma membrane than that of the axon membrane.

  11. Secondary electron emission from the entrance and exit surfaces of thin carbon foils under fast ion bombardment

    International Nuclear Information System (INIS)

    Shi, C.R.; Toh, H.S.; Lo, D.; Livi, R.P.; Mendenhall, M.H.; Zhang, D.Z.; Tombrello, T.A.

    1985-01-01

    The total secondary electron emission (SEE) yield from the entrance and exit surfaces of thin carbon foils under fast ion ( 16 O, 19 F, 35 Cl) bombardment has been measured as a function of the ion energy and the ion beam current intensity. Using a retarding field, the energy distribution of secondary electrons integrated over almost all angles of emission in the backward and forward directions has also been measured. It is found that total forward emission is larger than backward emission by factors of up to 2.5, 2.7, and 3.4 for 16 O +3 , 19 F +3 , and 35 Cl +5 , respectively. It is suggested that the enhancement of forward SEE may be partly due to effects from the instantaneous charge state of the heavy ion beam in the solid in addition to the binary collisions of the projectile with individual electrons in the target. It is also shown that the total SEE yield from the entrance and exit surfaces of the target foils decreases with ion beam current intensity; this may be a beam-induced temperature effect. The total SEE yield in both the forward and backward directions is less sensitive to surface conditions for high velocity ions than for low velocity ions, and the total yield from both surfaces of the foils is proportional to the ion stopping power in the target, where the constant of proportionality depends on the properties of material. (orig.)

  12. Plasmon-mediated electron emission from the coronene molecule under fast ion impact

    Science.gov (United States)

    Biswas, Shubhadeep; Tribedi, L. C.

    2015-12-01

    The existence of the collective electronic excitation in polycyclic aromatic hydrocarbon (PAH) molecules has been predicted before on the basis of the presence of a large delocalized π electron cloud around the carbon skeleton. Here, we present a manifestation of energy and angular distributions of electron emission upon deexcitation of the collective plasmon resonance in coronene, a PAH molecule, under fast ion impact. The angular distributions of these electrons show an unusually enhanced forward-backward angular asymmetry, in contrast to the observed uniform distributions for simpler atomic (Ne) or molecular (CH4) targets. A simple model of photoelectron angular distribution from an oscillating dipolar plasmon, calculated including the first retardation term in the transition matrix element, provides excellent agreement with the observed distribution. The ratio of forward-to-backward electron emission intensity clearly exhibits a broad peak which is in excellent agreement with the theoretical prediction of the plamson peak. This observation may provide some new inputs towards the astrophysical problem of UV photon absorption by PAHs in the interstellar medium, or in the search for materials suitable for UV plasmonics.

  13. Catapult mechanism for fast particle emission in fission and heavy ion reactions

    International Nuclear Information System (INIS)

    Maedler, P.

    1985-01-01

    The fission process of slabs of nuclear matter is modelled in TDHF approximation by adding an initial collective velocity field to the static self-consistent solution. In dependence on its amplitude either large amplitude density oscillations are excited or fission occurs. The final disintegration of the slab proceeds on a time scale of 10 -22 s and is characterized by a sharp peak in the actual velocity field in the region of the ''snatching'' inner low density tails. A characteristic time later corresponding to the transit time of a nucelon across the fragment with mean velocity being the Fermi velocity plus twice the maximum ''snatching'' velocity, a low density lump correlated with a peak in the velocity field emerges in front of the fragments. We call these particles ''catepult particles''. Recent experimental results possibly provide evidence for catapult neutron in low-energy fission. We also speculate on the significance of the catapult mechanism for fast particle emission in the exit channel of heavy ion reactions. (orig.)

  14. Catapult mechanism for fast particle emission in fission and heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Maedler, P.

    1985-05-01

    The fission process of slabs of nuclear matter is modelled in TDHF approximation by adding an initial collective velocity field to the static self-consistent solution. In dependence on its amplitude either large amplitude density oscillations are excited or fission occurs. The final disintegration of the slab proceeds on a time scale of 10/sup -22/s and is characterized by a sharp peak in the actual velocity field in the region of the ''snatching'' inner low density tails. A characteristic time later corresponding to the transit time of a nucelon across the fragment with mean velocity being the Fermi velocity plus twice the maximum ''snatching'' velocity, a low density lump correlated with a peak in the velocity field emerges in front of the fragments. We call these particles ''catepult particles''. Recent experimental results possibly provide evidence for catapult neutron in low-energy fission. We also speculate on the significance of the catapult mechanism for fast particle emission in the exit channel of heavy ion reactions.

  15. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    Energy Technology Data Exchange (ETDEWEB)

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-04-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles

  16. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    International Nuclear Information System (INIS)

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-01-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots (∼100 (micro)m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with ρr ∼ 2 g/cm 2 for a small demo/pilot plant producing ∼40 MJ of fusion yield per target, and (2) a large target with ρr ∼ 10 g/cm 2 producing ∼1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q ∼ 26) ion sources for short (∼5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of ∼10 MG fields to provide steep focusing angles close-in to the target (built-in as part of each target); (4) beam space charge

  17. Fast Data Acquisition in Heavy Ion CT Using Intensifying Screen—EMCCD Camera System With Beam Intensity Monitor

    Science.gov (United States)

    Muraishi, Hiroshi; Abe, Shinji; Satoh, Hitoshi; Hara, Hidetake; Mogaki, Tatsuya; Hara, Satoshi; Miyake, Shoko; Watanabe, Yusuke; Koba, Yusuke

    2012-10-01

    We investigated the feasibility of fast data acquisition in heavy ion CT (IonCT) technique with an X-ray intensifying screen-charged coupled device (CCD) camera system. This technique is based on measuring the residual range distribution of heavy ions after passing through an object. We took a large number of images with a CCD camera for one projection by changing the range shifter (RS) thickness to obtain a characteristic curve similar to a Bragg curve and then to estimate the relative residual range. We used a high quality Electron Multiplying CCD (EMCCD) camera, which drastically reduced data acquisition time. We also used a parallel-plate ionization chamber upstream of an object to monitor the time variation in heavy ion beam intensity from a synchrotron accelerator and to perform beam intensity correction for all EMCCD images. Experiments were conducted using a broad beam of 12C, which was generated by spreading out the pencil beam accelerated up to 400 MeV/u by the Heavy Ion Medical Accelerator, in Chiba (HIMAC) at the National Institute of Radiological Sciences, with a scatterer. We demonstrated that a fast CT data acquisition, 14 min for 256 projections, is possible for an electron density phantom, consisting of six rods with a relative electron density resolution of 0.017, using the proposed technique with HIMAC.

  18. Effect of giant plasmon excitations in single and double ionization of C60 in fast heavy-ion collisions

    Science.gov (United States)

    Kadhane, Umesh; Kelkar, A.; Misra, D.; Kumar, Ajay; Tribedi, Lokesh C.

    2007-04-01

    Single and multiple ionization of C60 in collisions with highly charged fast oxygen ions have been studied using the recoil-ion time-of-flight technique. The dependence of multiple-ionization cross sections on projectile charge state (qp) was found to be drastically different from those for an atomic target, such as Ne. A model based on the giant dipole plasmon resonance explains quite well the observed qp dependence for the single- and-double-ionization cross sections. But the same model deviates for triple and quadruple ionizations.

  19. Fast ion collisions with C 60 in vapour phase and collective excitation: Comparison with other gaseous targets

    Science.gov (United States)

    Tribedi, Lokesh C.; Kelkar, Aditya H.; Kasthurirangan, Siddharth

    2010-10-01

    The single and double ionization of a free C 60 molecule in collisions with fast heavy (F and Si) ions is investigated using a recoil ion time-of-flight mass spectrometer. The projectile charge state ( qp) dependence has also been investigated. A linear qp-dependence has been explained in terms of a plasmon excitation model. In addition, continuum electron spectroscopy has been used to detect the electron emission from fullerenes. The measured electron angular distribution for the fullerene target is compared with that for a gaseous target at a fixed electron energy. The ratio of forward-to-backward cross section for C 60 is quite different from that for Ne.

  20. Two Dual Ion Spectrometer Flight Units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS)

    Science.gov (United States)

    Adams, Mitzi

    2014-01-01

    Two Dual Ion Spectrometer flight units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS) have returned to MSFC for flight testing. Anticipated to begin on June 30, tests will ensue in the Low Energy Electron and Ion Facility of the Heliophysics and Planetary Science Office (ZP13), managed by Dr. Victoria Coffey of the Natural Environments Branch of the Engineering Directorate (EV44). The MMS mission consists of four identical spacecraft, whose purpose is to study magnetic reconnection in the boundary regions of Earth's magnetosphere.

  1. EFDA Task TW6-TPDS-DIADEV deliverable 2: ITER Fast Ion Collective Scattering Development of diagnostic components and techniques

    DEFF Research Database (Denmark)

    Michelsen, S.; Bindslev, Henrik; Korsholm, Søren Bang

    In 2003 the Risø CTS group finished a feasibility study and a conceptual design of an ITER fast ion collective Thomson scattering system. The purpose of the CTS diagnostic is to measure the distribution function of fast ions in the plasma with particular interest in fusion alphas. The feasibility...... study demonstrated that the only system, which can fully meet the ITER measurement requirements for confined fusion alphas, is a 60 GHz system. The study showed that by using two powerful microwave sources (gyrotrons) of this frequency both on the low field side, and two antenna systems, one on the low......) Optimisation of the design, considering the scattering geometries, variations in plasma profiles, magnetic equilibria etc. 2) Development of numerical codes for determination of the geometry of the antenna system on the high field side, including shapes and positions of mirrors and receiver horns. 3) A model...

  2. Fast ion measurements by collective Thomson scattering in TEXTOR and ASDEX Upgrade and proposal for the ITER CTS system

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran

    perpendicular to the magnetic field. The feasibility study and conceptual design of this diagnostic was provided by the CTS group at Risø DTU. The development of the ITER CTS diagnostic builds on the experiences and expertise gained from the construction and current operation of the CTS diagnostic systems......) provides the possibility of revealing the velocity distribution of the confined fast ions along a given direction – resolved both in time and space. Recently, the ITER baseline design has been expanded to include the enabling of the front end of a fast ion CTS diagnostic system resolving dynamics...... on TEXTOR and ASDEX Upgrade. This contribution will briefly introduce the technique of CTS, give an overview of the results of the current diagnostic systems at TEXTOR and ASDEX Upgrade, and present the chosen solution and the status of the design of the ITER CTS diagnostic system....

  3. Fast and sensitive determination of Sr-90 and SR-89 activity in milk by ion-chromatography and liquid scintillation

    International Nuclear Information System (INIS)

    Figueiredo, V.; Herrmann, A.

    1992-01-01

    A method for fast and exact determination of both strontium isotopes in milk and other foodstuffs, combination high performance ion chromatographic separation with by liquid scintillation counting, which enables the desired results to be obtained with very satisfactory precision and reproducibility within 24 hours, has been developed. The lowest detectable activity lies by 3 Bq/liter for Sr-90 and 1 Bq/liter for Sr-89 which is satisfactory for assessing a situation in a time crisis. (author)

  4. Analysis of resonant fast ion distributions during combined ICRF and NBI heating with transients using neutron emission spectroscopy

    Science.gov (United States)

    Hellesen, C.; Mantsinen, M.; Conroy, S.; Ericsson, G.; Eriksson, J.; Kiptily, V. G.; Nabais, F.; Contributors, JET

    2018-05-01

    ICRF heating at the fundamental cyclotron frequency of a hydrogen minority ion species also gives rise to a partial power absorption by deuterium ions at their second harmonic resonance. This paper studies the deuterium distributions resulting from such 2nd harmonic heating at JET using neutron emission spectroscopy data from the time of flight spectrometer TOFOR. The fast deuterium distributions are obtained over the energy range 100 keV to 2 MeV. Specifically, we study how the fast deuterium distributions vary as ICRF heating is used alone as well as in combination with NBI heating. When comparing the different heating scenarios, we observed both a difference in the shapes of the distributions as well as in their absolute level. The differences are most pronounced below 0.5 MeV. Comparisons are made with corresponding distributions calculated with the code PION. We find a good agreement between the measured distributions and those calculated with PION, both in terms of their shapes as well as their amplitudes. However, we also identified a period with signs of an inverted fast ion distribution, which showed large disagreements between the modeled and measured results. Resonant interactions with tornado modes, i.e. core localized toroidal alfven eigenmodes (TAEs), are put forward as a possible explanation for the inverted distribution.

  5. Self-consistent analysis of radial electric field and fast ion losses in CHS Torsatron/Heliotron

    International Nuclear Information System (INIS)

    Sanuki, H.; Itoh, K.; Itoh, S.

    1992-09-01

    A self-consistent analysis is developed to determine the radial electric field and loss cone boundary in Torsatron/Heliotron plasmas under the influence of non-classical ion losses such as the loss cone loss ans charge exchange loss of fast ions with neutrals. Analysis is applied to the NBI heated plasmas in the Compact Helical System (CHS) device. Comparison is made between theoretical results and experimental observations. The increased ion particle losses caused by the orbit loss and charge exchange loss with neutrals make the radial electric field more negative than the value of purely neoclassical calculation. The partition of the injection energy among the shine through, direct orbit loss, change exchange loss and bulk heating is evaluated by using the self-consistent electric field profile. On-going experiments in the CHS device are briefly introduced. (author)

  6. Development of the scintillator-based probe for fast-ion losses in the HL-2A tokamak

    International Nuclear Information System (INIS)

    Zhang, Y. P.; Liu, Yi; Yuan, G. L.; Song, X. Y.; Yang, J. W.; Li, X.; Chen, W.; Li, Y.; Yan, L. W.; Song, X. M.; Yang, Q. W.; Duan, X. R.; Luo, X. B.; Liu, Y. Q.; Hua, Y.; Isobe, M.

    2014-01-01

    A new scintillator-based lost fast-ion probe (SLIP) has been developed and operated in the HL-2A tokamak [L. W. Yan, X. R. Duan, X. T. Ding, J. Q. Dong, Q. W. Yang, Yi Liu, X. L. Zou, D. Q. Liu, W. M. Xuan, L. Y. Chen, J. Rao, X. M. Song, Y. Huang, W. C. Mao, Q. M. Wang, Q. Li, Z. Cao, B. Li, J. Y. Cao, G. J. Lei, J. H. Zhang, X. D. Li, W. Chen, J. Chen, C. H. Cui, Z. Y. Cui, Z. C. Deng, Y. B. Dong, B. B. Feng, Q. D. Gao, X. Y. Han, W. Y. Hong, M. Huang, X. Q. Ji, Z. H. Kang, D. F. Kong, T. Lan, G. S. Li, H. J. Li, Qing Li, W. Li, Y. G. Li, A. D. Liu, Z. T. Liu, C. W. Luo, X. H. Mao, Y. D. Pan, J. F. Peng, Z. B. Shi, S. D. Song, X. Y. Song, H. J. Sun, A. K. Wang, M. X. Wang, Y. Q. Wang, W. W. Xiao, Y. F. Xie, L. H. Yao, D. L. Yu, B. S. Yuan, K. J. Zhao, G. W. Zhong, J. Zhou, J. C. Yan, C. X. Yu, C. H. Pan, Y. Liu, and the HL-2A Team , Nucl. Fusion 51, 094016 (2011)] to measure the losses of neutral beam ions. The design of the probe is based on the concept of the α-particle detectors on Tokamak Fusion Test Reactor (TFTR) using scintillator plates. The probe is capable of traveling across an equatorial plane port and sweeping the aperture angle rotationally with respect to the axis of the probe shaft by two step motors, in order to optimize the radial position and the collimator angle. The energy and the pitch angle of the lost fast ions can be simultaneously measured if the two-dimensional image of scintillation light intensity due to the impact of the lost fast ions is detected. Measurements of the fast-ion losses using the probe have been performed during HL-2A neutral beam injection discharges. The clear experimental evidence of enhanced losses of beam ions during disruptions has been obtained by means of the SLIP system. A detailed description of the probe system and the first experimental results are reported

  7. Development of the scintillator-based probe for fast-ion losses in the HL-2A tokamak

    Science.gov (United States)

    Zhang, Y. P.; Liu, Yi; Luo, X. B.; Isobe, M.; Yuan, G. L.; Liu, Y. Q.; Hua, Y.; Song, X. Y.; Yang, J. W.; Li, X.; Chen, W.; Li, Y.; Yan, L. W.; Song, X. M.; Yang, Q. W.; Duan, X. R.

    2014-05-01

    A new scintillator-based lost fast-ion probe (SLIP) has been developed and operated in the HL-2A tokamak [L. W. Yan, X. R. Duan, X. T. Ding, J. Q. Dong, Q. W. Yang, Yi Liu, X. L. Zou, D. Q. Liu, W. M. Xuan, L. Y. Chen, J. Rao, X. M. Song, Y. Huang, W. C. Mao, Q. M. Wang, Q. Li, Z. Cao, B. Li, J. Y. Cao, G. J. Lei, J. H. Zhang, X. D. Li, W. Chen, J. Chen, C. H. Cui, Z. Y. Cui, Z. C. Deng, Y. B. Dong, B. B. Feng, Q. D. Gao, X. Y. Han, W. Y. Hong, M. Huang, X. Q. Ji, Z. H. Kang, D. F. Kong, T. Lan, G. S. Li, H. J. Li, Qing Li, W. Li, Y. G. Li, A. D. Liu, Z. T. Liu, C. W. Luo, X. H. Mao, Y. D. Pan, J. F. Peng, Z. B. Shi, S. D. Song, X. Y. Song, H. J. Sun, A. K. Wang, M. X. Wang, Y. Q. Wang, W. W. Xiao, Y. F. Xie, L. H. Yao, D. L. Yu, B. S. Yuan, K. J. Zhao, G. W. Zhong, J. Zhou, J. C. Yan, C. X. Yu, C. H. Pan, Y. Liu, and the HL-2A Team, Nucl. Fusion 51, 094016 (2011)] to measure the losses of neutral beam ions. The design of the probe is based on the concept of the α-particle detectors on Tokamak Fusion Test Reactor (TFTR) using scintillator plates. The probe is capable of traveling across an equatorial plane port and sweeping the aperture angle rotationally with respect to the axis of the probe shaft by two step motors, in order to optimize the radial position and the collimator angle. The energy and the pitch angle of the lost fast ions can be simultaneously measured if the two-dimensional image of scintillation light intensity due to the impact of the lost fast ions is detected. Measurements of the fast-ion losses using the probe have been performed during HL-2A neutral beam injection discharges. The clear experimental evidence of enhanced losses of beam ions during disruptions has been obtained by means of the SLIP system. A detailed description of the probe system and the first experimental results are reported.

  8. thermal, electrical and structural characterization of fast ion conducting glasses (Ag Br)x(AgPO)1-x

    International Nuclear Information System (INIS)

    Kartini, E.; Yufus, S.; Priyanto, T; Indayaningsih, N; Collins, M F

    2001-01-01

    Fast ion conducting glasses are of considerable technological interest because of their possible application in batteries, sensors, and displays. One of the main scientific challenges is to explain how the disordered structure of the glass is related to the high ionic conductivity that can be achieved at ambient temperature. Fast ion conducting glasses (AgBr) x (AgPO3) 1- x with x=0.0; 0.2; 0.3; 0.4; 0.5; 0.7; and 0.85 were prepared by rapid quenching. The studies of structure, thermal property and electrical conductivity have been made. The X-ray diffraction patterns of this system show that the sample are glasses for x 0.5. The neutron diffraction data shows that all AgBr doped glasses exhibit a strong and relatively sharp diffraction peak at anomalously low momentum transfer value, Q∼ 0.7 Α - 1. The low Q-peak is not observed in AgPO 3 glass, and in the X-ray data. The results of electrical conductivity show that the conduction is essentially ionic and due to silver ions alone. The logarithm of the ionic conductivity increases with increasing AgBr mole fraction, and reaches maximum for x = 0.5. The thermal property results measured by differential scanning calorimetric show that the temperatures of the glass transition, the crystallization and the melt reach minimum for the glass with composition x 0.5. We conclude that there appears to be a relation between higher conductivity at ambient temperature, and the low Q-peak. Based on this investigation a better fast ion conducting glass proposed is (AgBr) 0 .5(AgPO 3 ) 0 .5 with the conductivity of 8 x 10 - 5 S/cm

  9. Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.

    Science.gov (United States)

    García-Muñoz, M; Fahrbach, H-U; Zohm, H

    2009-05-01

    A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].

  10. Fast heavy ion collisions with C{sub 60}: Collective excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kadhane, Umesh [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Kelkar, A.H. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Misra, D. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Kumar, Ajay [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Tribedi, L.C. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India)]. E-mail: lokesh@tifr.res.in

    2006-11-15

    Ionization and fragmentation of C{sub 60} in collision with 5 MeV/{mu}m O{sup 6+} ions are studied using recoil ion ToF method. Relative ionization cross sections up to C{sub 60} {sup 4+} are determined. The qualitative trend for different C{sub 60} charge states was compared against simple plasmon excitation model.

  11. Ion Fast Ignition-Establishing a Scientific Basis for Inertial Fusion Energy --- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Richard Burnite [General Atomics; Foord, Mark N. [Lawrence Livermore National Laboratory; Wei, Mingsheng [General Atomics; Beg, Farhat N. [University of California, San Diego; Schumacher, Douglass W. [The Ohio State University

    2013-10-31

    The Fast Ignition (FI) Concept for Inertial Confinement Fusion (ICF) has the potential to provide a significant advance in the technical attractiveness of Inertial Fusion Energy reactors. FI differs from conventional ?central hot spot? (CHS) target ignition by decoupling compression from heating: using a laser (or heavy ion beam or Z pinch) drive pulse (10?s of nanoseconds) to create a dense fuel and a second, much shorter (~10 picoseconds) high intensity pulse to ignite a small volume within the dense fuel. The compressed fuel is opaque to laser light. The ignition laser energy must be converted to a jet of energetic charged particles to deposit energy in the dense fuel. The original concept called for a spray of laser-generated hot electrons to deliver the energy; lack of ability to focus the electrons put great weight on minimizing the electron path. An alternative concept, proton-ignited FI, used those electrons as intermediaries to create a jet of protons that could be focused to the ignition spot from a more convenient distance. Our program focused on the generation and directing of the proton jet, and its transport toward the fuel, none of which were well understood at the onset of our program. We have developed new experimental platforms, diagnostic packages, computer modeling analyses, and taken advantage of the increasing energy available at laser facilities to create a self-consistent understanding of the fundamental physics underlying these issues. Our strategy was to examine the new physics emerging as we added the complexity necessary to use proton beams in an inertial fusion energy (IFE) application. From the starting point of a proton beam accelerated from a flat, isolated foil, we 1) curved it to focus the beam, 2) attached the foil to a superstructure, 3) added a side sheath to protect it from the surrounding plasma, and finally 4) studied the proton beam behavior as it passed through a protective end cap into plasma. We built up, as we proceeded

  12. Vitamin D-metabolites from human plasma and mass spectrometric analysis by fast heavy ion induced desorption

    International Nuclear Information System (INIS)

    Fohlman, J.; Peterson, P.A.

    1982-01-01

    D-vitamin metabolites have been isolated from human serum employing chromatographic techniques. The serum carrier protein for vitamin D (DBP) was first isolated by immunosorbent chromatography. Lipid ligands associated with DBP were then extracted with hexane and separated by high pressure liquid chromatography (HPLC). Detection of vitamin D metabolites by their absorbance of ultraviolet light is not sufficiently sensitive to monitor all vitamin D derivatives from a few millilitres of serum. Therefore, further analyses are necessary to quantitative these compounds. We have begun to develop a mass spectrometric method to achieve a reliable, quantitative procedure. As a first step towards this goal a number of pure samples of vitamin D compounds have been studied in a time-of-flight mass spectrometer based on fast heavy ion induced desorption. All vitamin D compounds examined could be detected and identified by their molecular ion and fragment spectra. (orig.)

  13. Damage and polymerization of C sub 6 sub 0 films irradiated by fast light and heavy ions

    CERN Document Server

    Yogo, A; Itoh, A

    2002-01-01

    C sub 6 sub 0 films have been irradiated with various fast ions (H, Li, C, O and Si) in the energy range from 0.75 to 6.0 MeV. Structural changes of C sub 6 sub 0 molecules were studied by a time-of-flight (TOF) mass spectrometry and Raman spectroscopy. The TOF yields of secondary fullerene ions can be described fairly well by S sub m sub o sub d sup 3 with a modified energy deposition S sub m sub o sub d developed in this work. In the Raman study for 1 MeV H sup + irradiation, it is found that about 40% polymerization is attained at 6x10 sup 1 sup 5 cm sup - sup 2 doses and a damage cross-section of 2.5x10 sup - sup 1 sup 7 cm sup 2 is obtained.

  14. Fast ion collisions with C{sub 60} in vapour phase and collective excitation: Comparison with other gaseous targets

    Energy Technology Data Exchange (ETDEWEB)

    Tribedi, Lokesh C., E-mail: lokesh@tifr.res.i [Tata Institute of Fundamental Research, Mumbai (India); Kelkar, Aditya H. [Tata Institute of Fundamental Research, Mumbai (India); Kasthurirangan, Siddharth [Tata Institute of Fundamental Research, Mumbai (India); Institute of Chemical Technology, Mumbai (India)

    2010-10-01

    The single and double ionization of a free C{sub 60} molecule in collisions with fast heavy (F and Si) ions is investigated using a recoil ion time-of-flight mass spectrometer. The projectile charge state (q{sub p}) dependence has also been investigated. A linear q{sub p}-dependence has been explained in terms of a plasmon excitation model. In addition, continuum electron spectroscopy has been used to detect the electron emission from fullerenes. The measured electron angular distribution for the fullerene target is compared with that for a gaseous target at a fixed electron energy. The ratio of forward-to-backward cross section for C{sub 60} is quite different from that for Ne.

  15. Forward backward asymmetry in electron emission from H{sub 2}by fast carbon ions and Young type interference effect

    Energy Technology Data Exchange (ETDEWEB)

    Misra, D [Tata Institute of Fundamental Research, H. B. Road, Colaba, Mumbai-400005 (India); Kelkar, A H [Tata Institute of Fundamental Research, H. B. Road, Colaba, Mumbai-400005 (India); Kadhane, U [Tata Institute of Fundamental Research, H. B. Road, Colaba, Mumbai-400005 (India); Kumar, A; Fainstein, Pd [Centro Atomico Bariloche, 8400 Bariloche (Argentina); Tribedi, L C [Tata Institute of Fundamental Research, H. B. Road, Colaba, Mumbai-400005 (India)

    2007-03-01

    We have investigated the effect of Young type interference on the forward backward angular asymmetry in electron emission from molecular hydrogen in collisions with fast bare carbon ions. The asymmetry parameter shows an oscillatory behaviour as a function of electron velocity which is absent in atomic target such as He. It is shown that the asymmetry parameter which is based on DDCS from H{sub 2}only can be a tool to investigate the Young type interference. The measured energy and angular distributions as well as the asymmetry parameter are compared with a molecular CDW-EIS (continuum distorted wave-eikonal initial state) model.

  16. Overcoming a fast transverse instability by means of octupole-induced tune spread in the Relativistic Heavy Ion Collider

    Directory of Open Access Journals (Sweden)

    C. Montag

    2002-08-01

    Full Text Available During the Relativistic Heavy Ion Collider commissioning in 2001 a fast transverse instability was observed on the ramp. In general this could be counteracted with increased chromaticity, resulting in Landau damping. However this method could not be applied around transition energy where chromaticities have to change sign. So octupoles were used near transition energy to create transverse Landau damping and avoid the transverse instability, emittance blowup, and beam loss. This paper describes the considerations that led to the present scheme, as well as experimental results.

  17. Transmission of Fast Highly Charged Ions through a Single Glass Macrocapillary and Polycarbonate Nanocapillary Foils

    Science.gov (United States)

    Ayyad, A. M.; Dassanayake, B. S.; Keerthisinghe, D.; DeSilva, G. G.; Elkafrawy, T.; Kayani, N.; Tanis, J. A.

    2012-11-01

    Transmission of 3 MeV protons and 16 MeV O5+ ions through a single glass macrocapillary and a polycarbonate nanocapillary foil has been investigated. Results show that 3 MeV protons transmit through the capillary and the foils with little or no energy loss, while 16 MeV O5+ ions show transmission through the capillary and the foil with energy losses that vary with the tilt angle, and there are also changes in the charge state.

  18. Characterization of synthetic dyes by comprehensive two-dimensional liquid chromatography combining ion-exchange chromatography and fast ion-pair reversed-phase chromatography.

    Science.gov (United States)

    Pirok, Bob W J; Knip, Jitske; van Bommel, Maarten R; Schoenmakers, Peter J

    2016-03-04

    In the late 19th century, newly invented synthetic dyes rapidly replaced the natural dyes on the market. The characterization of mixtures of these so-called early synthetic dyes is complicated through the occurrence of many impurities and degradation products. Conventional one-dimensional liquid chromatography does not suffice to obtain fingerprints with sufficient resolution and baseline integrity. Comprehensive two-dimensional liquid chromatography (LC×LC) is employed in this study, with ion-exchange chromatography in the first dimension and fast ion-pair liquid chromatography in the second. Retention in the first dimension is largely determined by the number of charges, while the selection of a small ion-pair reagent (tetramethylammonium hydroxide) in the second dimension causes retention to be largely determined by the molecular structure of the dye. As a result, there is a high degree of orthogonality of the two dimensions, similar to the values typically encountered in GC×GC. The proposed LC×LC method shows a theroretical peak capacity of about 2000 in an analysis time of about three hours. Clear, informative fingerprints are obtained that open a way to a more efficient characterization of dyes used in objects of cultural heritage. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Fast-ignition heavy-ion fusion target by jet impact

    Energy Technology Data Exchange (ETDEWEB)

    Velarde, P. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, C/ Jose Gutierrez Abascal, 2. 28006 Madrid (Spain)]. E-mail: pedro@din.upm.es; Ogando, F. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, C/ Jose Gutierrez Abascal, 2. 28006 Madrid (Spain); Universidad Nacional de Educacion a Distancia (Spain); Eliezer, S. [Soreq Nuclear Research Center (Israel); Martinez-Val, J.M. [Soreq Nuclear Research Center (Israel)

    2005-05-21

    A new target design for HIF, based on the fast-ignition principles, is proposed. Unlike the previous designs proposed so far, in this case just one energy source is needed to drive the whole process to ignition. The ultra-fast deposition of energy onto the compressed core is produced in this case by hypervelocity jets generated during the process. The collision of jets converts their kinetic energy into thermal energy of the nuclear fuel, which is expected to produce ignition under proper design. The process is studied in this paper, describing its most relevant features like jet production and later collision.

  20. An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS for fast PAN and PPN measurements

    Directory of Open Access Journals (Sweden)

    H. Schlager

    2011-02-01

    Full Text Available An airborne chemical ionization ion trap mass spectrometer instrument (CI-ITMS has been developed for tropospheric and stratospheric fast in-situ measurements of PAN (peroxyacetyl nitrate and PPN (peroxypropionyl nitrate. The first scientific deployment of the FASTPEX instrument (FASTPEX = Fast Measurement of Peroxyacyl nitrates took place in the Arctic during 18 missions aboard the DLR research aircraft Falcon, within the framework of the POLARCAT-GRACE campaign in the summer of 2008. The FASTPEX instrument is described and characteristic properties of the employed ion trap mass spectrometer are discussed. Atmospheric data obtained at altitudes of up to ~12 km are presented, from the boundary layer to the lowermost stratosphere. Data were sampled with a time resolution of 2 s and a 2σ detection limit of 25 pmol mol−1. An isotopically labelled standard was used for a permanent on-line calibration. For this reason the accuracy of the PAN measurements is better than ±10% for mixing ratios greater than 200 pmol mol−1. PAN mixing ratios in the summer Arctic troposphere were in the order of a few hundred pmol mol−1 and generally correlated well with CO. In the Arctic boundary layer and lowermost stratosphere smaller PAN mixing ratios were observed due to a combination of missing local sources of PAN precursor gases and efficient removal processes (thermolysis/photolysis. PPN, the second most abundant PAN homologue, was measured simultaneously. Observed PPN/PAN ratios range between ~0.03 and 0.3.

  1. 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

  2. Ionization and fragmentation of water clusters by fast highly charged ions

    International Nuclear Information System (INIS)

    Adoui, L; Cassimi, A; Gervais, B; Grandin, J-P; Guillaume, L; Maisonny, R; Legendre, S; Tarisien, M; Lopez-Tarifa, P; Alcami, M; Martin, F; Politis, M-F; Penhoat, M-A Herve du; Vuilleumier, R; Gaigeot, M-P; Tavernelli, I

    2009-01-01

    We study the dissociative ionization of water clusters by impact of 12 MeV/u Ni 25+ ions. Cold target recoil ion momentum spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility of the ionized water clusters. An unusual stability of the H 9 O + 4 ion is observed, which could be the signature of the so-called Eigen structure in gas-phase water clusters. From the analysis of coincidences between charged fragments, we conclude that charge mobility is very high and is responsible for the formation of protonated water clusters, (H 2 O) n H + , that dominate the mass spectrum. These results are supported by Car-Parrinello molecular dynamics and time-dependent density functional theory simulations, which also reveal the mechanisms of such mobility.

  3. Demonstrated Efficient Quasi-Monoenergetic Carbon-Ion Beams Approaching Fast Ignition (FI) Requirements

    Science.gov (United States)

    Fernández, Juan C.; Palaniyappan, S.; Huang, C.; Gautier, D. C.; Santiago, M.

    2015-11-01

    Using massive computer simulations of relativistic laser-plasma interactions, we have identified a self-organizing scheme that exploits persisting self-generated plasma electric (~TV/m) and magnetic (~104 Tesla) fields to reduce the ion energy spread of intense laser-driven ion beams after the laser exits the plasma. Consistent with the scheme, we have demonstrated on the LANL Trident laser carbon-ion beams with narrow spectral peaks at 220 MeV, with high conversion efficiency (~ 5%). These parameters are within a factor of 2 of FI requirements. The remaining gap may be bridged by increasing the laser intensity by a factor of 4, according to our data. We also discuss how this beam may be focused, to address the remaining requirement for FI, besides the total laser energy. This work is sponsored by the LANL LDRD Program.

  4. On the symmetry of cylindrical implosions driven by a rotating beam of fast ions

    International Nuclear Information System (INIS)

    Basko, M.M.; Schlegel, T.; Maruhn, J.

    2004-01-01

    Cylindrical implosions driven by intense beams of heavy ions are one of the promising ways to create high energy density states in matter. To ensure the needed azimuthal symmetry of the beam energy deposition, it was proposed [Sharkov et al., Nucl. Instrum. Methods Phys. Res. A 464, 1 (2001)] to rotate the ion beam around the target axis. Combining analytical calculations with two-dimensional hydrodynamic simulations, a lower limit is established on the frequency ν of the beam rotation dictated by the target hydrodynamics. This limit is shown to be directly proportional to the desired radial convergence ratio C r for stepwise beam power profiles, and to C r 1/2 for smooth pulses. With a smooth pulse, 6-10 beam revolutions per pulse should be sufficient to reach C r ≅30, while a stepwise pulse requires ≅100 revolutions. Also, the upper bound on the asymmetry of the elliptical focal spot of a rotating ion beam is calculated

  5. Influence of partial ionization on the energy loss of fast ions in high- Z material

    Energy Technology Data Exchange (ETDEWEB)

    Peter, T. (Max-Planck-Institut fuer Chemie, D-6500 Mainz, Germany (DE)); Kaercher, B. (Max-Planck-Institut fuer Quantenoptik, D-8046 Garching, Germany (DE))

    1991-04-01

    Analytical and simple numerical calculations of the stopping power of partially ionized high-{ital Z} targets are presented. Up to now such calculations are difficult, mainly because of lacking precise average ionization potentials of the target ions. The aim of this paper is both to clarify the importance of a suitable treatment of target ions in different ionization stages and to show by means of general scaling laws and explicit examples, that high-{ital Z} plasmas of high density and low ionization degree may have smaller stopping powers than cold matter. The resulting range lengthening of the projectile ions might be of crucial importance for a proper design of pellets in inertial confinement fusion.

  6. Electron loss from fast partially stripped C and O ions incident on crystal targets

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Hiroshi E-mail: kudo@bukko.bk.tsukuba.ac.jp; Takeda, Ken-ichi; Suguri, Takuya; Iwazaki, Wataru; Sakurai, Chizuko; Arano, Isamu; Numazawa, Shuhei; Seki, Seiji

    2003-07-01

    We have measured energy spectra of electrons emitted in a backward direction of Si and Ge crystals while bombarded by 2.5 and 3.5 MeV/u C{sup 4+}, C{sup 6+}, O{sup 5+} and O{sup 8+}. Under <1 1 0> channeling incidence conditions, the loss electron yield from the partially stripped ions is appreciably reduced (by a factor of 0.5-0.6 for C{sup 4+}) relative to the non-channeling case. This reduction can be directly related to the reduced charge states of the channeled ions in the crystals. Furthermore, the evolution of the pre-equilibrium charge states of the incident ions has been deduced from a comparison of the effective nuclear charges for the loss electron yield, the low-energy electron yield, and the binary-encounter electron yield reported previously.

  7. Broadening of ICRH produced fast ion profiles due to orbit effects

    International Nuclear Information System (INIS)

    Eriksson, L.-G.; Porcelli, F.

    1991-01-01

    In the JET tokamak, minority ions accelerated by ICRH reach energies in the MeV range. Near the plasma magnetic axis, the standard trapped particle ''banana'' orbit is distorted into a ''potato'' or ''fat banana'' orbit. The zero banana width approximation which is used in most Fokker-Planck calculations of velocity distributions of resonating ions is often not valid in JET. The inclusion of finite banana width effects will, in general, lead to a lowering of the averaged tail energy and a broadening of pressure profiles, power transfer profiles etc. A model for calculating orbit broadened profiles is presented. (Author)

  8. Planar self-aligned ion implanted InP MISFETS for fast logic applications

    International Nuclear Information System (INIS)

    Cameron, D.C.; Irving, L.D.; Whitehouse, C.R.; Woodward, J.; Lee, D.

    1983-01-01

    The first successful use of ion implantation to fabricate truly self-aligned planar n-channel enhancement-mode indium phosphide MISFITS is reported. The transistors have been fabricated on iron-doped semi-insulating material using PECVD-deposited SiO 2 as the gate dielectric and molybdenum gate electrodes. The self-aligned source and drain contact regions were produced by Si 29 ion implantation using each gate stripe as an implant mask. The devices fabricated to date have exhibited channel mobilities up to value of 2400 cm 2 v -1 s -1 , with excellent uniformity and stability of the device characteristics also being observed. (author)

  9. Use of positive ion fast atom bombardment mass spectrometry for rapid identification of a bile alcohol glucuronide isolated from cerebrotendinous xanthomatosis patients

    International Nuclear Information System (INIS)

    Dayal, B.; Salen, G.; Tint, G.S.; Shefer, S.; Benz, S.W.

    1990-01-01

    The identification of a major biliary and plasma bile alcohol glucuronide, 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol-3-0-beta-D-glucuronide, present in cerebrotendinous xanthomatosis (CTX) patients, was investigated by positive ion fast atom bombardment mass spectrometry (FAB-MS). The spectrum was characterized by abundant ions formed by attachment of a proton, [M + H]+, or of alkali ions, [M + Na]+ and [M + 39K]+, to the glucuronide salt. These ions allowed an unambiguous deduction of the molecular weight of the sample. It is suggested that FAB-MS could be used in the rapid diagnosis of CTX

  10. Actin filaments as the fast pathways for calcium ions involved in ...

    Indian Academy of Sciences (India)

    2015-08-14

    Aug 14, 2015 ... stimulus; spring of tip-link exerts a force on the trap door and opens the ionic channel. 550. Miljko V Sataric et al. ... copy to detect Ca2+ ions entry and distribution within stereo- cilia of hair cells. They also .... resistance R0 ~ 108 Ω. The corresponding characteristic time of discharging such elementary unit is ...

  11. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    International Nuclear Information System (INIS)

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.; Pikin, A. I.

    2015-01-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz

  12. Measurements of atomic transition probabilities in highly ionized atoms by fast ion beams

    International Nuclear Information System (INIS)

    Martinson, I.; Curtis, L.J.; Lindgaerd, A.

    1977-01-01

    A summary is given of the beam-foil method by which level lifetimes and transition probabilities can be determined in atoms and ions. Results are presented for systems of particular interest for fusion research, such as the Li, Be, Na, Mg, Cu and Zn isoelectronic sequences. The available experimental material is compared to theoretical transition probabilities. (author)

  13. Actin filaments as the fast pathways for calcium ions involved in ...

    Indian Academy of Sciences (India)

    We investigated the polyelectrolyte properties of actin filaments which are in interaction with myosin motors, basic participants in mechano-electrical transduction in the stereocilia of the inner ear. Here, we elaborated a model in which actin filaments play the role of guides or pathways for localized flow of calcium ions.

  14. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Nielsen, Stefan Kragh; Porte, L.

    2007-01-01

    ) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also...

  15. Nanoconfined LiBH4 as a Fast Lithium Ion Conductor

    NARCIS (Netherlands)

    Blanchard, Didier; Nale, Angeloclaudio; Sveinbjoernsson, Dadi; Eggenhuisen, Tamara M.; Verkuijlen, Margriet H. W.; Suwarno, Suwarno; Vegge, Tejs; Kentgens, Arno P. M.; de Jongh, Petra E.

    2015-01-01

    Designing new functional materials is crucial for the development of efficient energy storage and conversion devices such as all solid-state batteries. LiBH4 is a promising solid electrolyte for Li-ion batteries. It displays high lithium mobility, although only above 110 degrees C at which a

  16. Fast and noise-resistant ion-trap quantum computation with inherent dynamical decoupling

    Science.gov (United States)

    Zheng, Shi-Biao

    2014-02-01

    We propose a scheme for realizing quantum logic gates between any pair of ions confined in a linear trap with a pair of laser beams tuned to the carrier. The striking feature of the scheme is that the carrier excitation accompanying the spin-motion coupling does not affect the gate dynamics. As a consequence, the gate not only is much more insensitive to motional heating but also can operate at a higher speed compared to the previous schemes. The other important advantages are that the gate speed does not need to be inversely proportional to the number of ions in the chain, and the accompanying carrier drive results in dynamical decoupling, making the gate performance robust against dephasing noises. We show that for the same error sources the gate infidelity can be decreased by about ten times compared with previous schemes.

  17. Fast-scan monitor examines neutral-beam ion-density profile

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    All of the magnetic mirror confinement fusion experiments at LLL and at other laboratories depend on pulsed, energetic neutral-beam injection for fueling and imparting energy to the trapped plasma for density build-up and stability studies. It is vital to be able to monitor how well the injected ion beam is aimed and focused. To do this, we have designed an ion-beam current-density profile monitor that uses a commercial minimodular data acquisition system. Our prototype model monitors a single 20-kV, 50-A, 10-ms beam. However, the method is applicable to any number of beams with similar sampling target arrays. Also, the electronics can be switched to monitor any one of several target collectors

  18. Excited state populations and charge-exchange of fast ions in solids

    International Nuclear Information System (INIS)

    Miller, P.D.; Sofield, C.J.; Woods, C.J.

    1984-01-01

    Excited state populations and charge state fractions of 445 MeV Cl ions have been measured for a range of thicknesses of solid C targets. Cross sections for electron capture, loss, excitation and excited state quenching have been determined and these data are found to predict a quantitative difference between equilibrium charge state distributions from gases and solids for a special case of the Bohr-Lindhard density effect model. 8 references, 1 figure, 1 table

  19. Electron interference in fast ion collisions with H2 and the frequency parameter

    Science.gov (United States)

    Chatterjee, S.; Misra, D.; Fainstein, P. D.; Tribedi, L. C.

    2011-06-01

    The Young-type interference effect has been investigated in electron emission from molecular hydrogen in collision of 5 MeV u- 1 F9+ ions. The double differential cross section ratios of molecular-to-atomic hydrogen exhibits oscillatory structure, which is discussed in terms of the Young-type electron interference. We have obtained the frequencies of such oscillation for different angles. A comparative study of the frequency parameter is given with early measurements performed by other groups.

  20. Interaction of powerful hot plasma and fast ion streams with materials in dense plasma focus devices

    Czech Academy of Sciences Publication Activity Database

    Chernyshova, M.; Gribkov, V. A.; Kowalska-Strzeciwilk, E.; Kubkowska, M.; Miklaszewski, R.; Paduch, M.; Pisarczyk, T.; Zielinska, E.; Demina, E.V.; Pimenov, V. N.; Maslyaev, S. A.; Bondarenko, G.G.; Vilémová, Monika; Matějíček, Jiří

    2016-01-01

    Roč. 113, December (2016), s. 109-118 ISSN 0920-3796 R&D Projects: GA ČR(CZ) GA14-12837S Institutional support: RVO:61389021 Keywords : Radiation damageability * Material s tests * Plasma focus * Plasma streams * Ion beams * Laser interferometrya Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.319, year: 2016 http://www.sciencedirect.com/science/article/pii/S0920379616306858

  1. A fast spectroscopic diagnostic for the measurement of plasma impurity ion dynamics

    International Nuclear Information System (INIS)

    Den Hartog, D.J.; Fonck, R.J.

    1994-04-01

    A high-resolution spectrometer has been developed and used to measure simultaneously impurity ion temperature and flow velocities in high temperature plasmas with 10 μs temporal resolution (limited by digitization rate). This device is actually a duo-spectrometer: measurements from two different chordal views of the plasma can be made simultaneously via two separate quartz input fiber optic bundles coupled to the entrance slits which are tilted to compensate for line curvature. The dispersed spectra on the exit plane of the duo-spectrometer are coupled via quartz fiber optics to two arrays of 16 photomultiplier tubes each. Measurement made by recording the Doppler broadened and shifted 227.091 nm emission from the CV impurity ions in the MST reversed-field pinch (RFP) plasma have achieved precisions of <6 eV for temperatures of 150 Ev and <0.7 km/s for flow velocities of 6 km/s. Representative results from the MsT RFP indicate that the toroidal flow velocity drops and ion temperature increases during saw tooth events in MST

  2. An improved routine for the fast estimate of ion cyclotron heating efficiency in tokamak plasmas

    International Nuclear Information System (INIS)

    Brambilla, M.

    1992-02-01

    The subroutine ICEVAL for the rapid simulation of Ion Cyclotron Heating in tokamak plasmas is based on analytic estimates of the wave behaviour near resonances, and on drastic but reasonable simplifications of the real geometry. The subroutine has been rewritten to improve the model and to facilitate its use as input in transport codes. In the new version the influence of quasilinear minority heating on the damping efficiency is taken into account using the well-known Stix analytic approximation. Among other improvements are: a) the possibility of considering plasmas with more than two ion species; b) inclusion of Landau, Transit Time and collisional damping on the electrons non localised at resonances; c) better models for the antenna spectrum and for the construction of the power deposition profiles. The results of ICEVAL are compared in detail with those of the full-wave code FELICE for the case of Hydrogen minority heating in a Deuterium plasma; except for details which depend on the excitation of global eigenmodes, agreement is excellent. ICEVAL is also used to investigate the enhancement of the absorption efficiency due to quasilinear heating of the minority ions. The effect is a strongly non-linear function of the available power, and decreases rapidly with increasing concentration. For parameters typical of Asdex Upgrade plasmas, about 4 MW are required to produce a significant increase of the single-pass absorption at concentrations between 10 and 20%. (orig.)

  3. A high-power and fast charging Li-ion battery with outstanding cycle-life.

    Science.gov (United States)

    Agostini, M; Brutti, S; Navarra, M A; Panero, S; Reale, P; Matic, A; Scrosati, B

    2017-04-24

    Electrochemical energy storage devices based on Li-ion cells currently power almost all electronic devices and power tools. The development of new Li-ion cell configurations by incorporating innovative functional components (electrode materials and electrolyte formulations) will allow to bring this technology beyond mobile electronics and to boost performance largely beyond the state-of-the-art. Here we demonstrate a new full Li-ion cell constituted by a high-potential cathode material, i.e. LiNi 0.5 Mn 1.5 O 4 , a safe nanostructured anode material, i.e. TiO 2 , and a composite electrolyte made by a mixture of an ionic liquid suitable for high potential applications, i.e. Pyr 1,4 PF 6 , a lithium salt, i.e. LiPF 6 , and standard organic carbonates. The final cell configuration is able to reversibly cycle lithium for thousands of cycles at 1000 mAg -1 and a capacity retention of 65% at cycle 2000.

  4. Classical-quantum correspondence for ionization in fast ion-atom collisions

    International Nuclear Information System (INIS)

    Burgdoerfer, J.; Reinhold, C.O.

    1994-01-01

    We analyze the interplay between classical and quantum dynamics in ionization of atoms by fast charged particles The convergence to the classical limit is studied as a function of the momentum transferred to the electron during the collision, the impact parameter. the energy and angle of the emitted electron, and the initial state of the target. One goal is to assess the validity of exact classical (CTMC) methods and approximate classical models such as the Thomson model. Applications to data for electron ejection at large angles are presented. The connection between collisional ionization by charged particles and ionization by half-cycle pulses is discussed

  5. Ion desorption from solid surfaces under slow (KeV) and fast (MeV) ion sputtering. Influence of the charge state and of the incidence angle on the input channel

    International Nuclear Information System (INIS)

    Joret, H.

    1990-06-01

    Solid surfaces of organic and inorganic materials have been bombarded by fast heavy ions (several MeV). It is shown that the charge state of the projectile has a strong influence on the atomic and molecular ion desorption yield. Experimental studies proved that molecular ions can be emitted intact from deep layers underneath the surface (volume emission) with the existence of a crater emission. On the other hand light ions like H(+), H(+)-2, H(+)-3 are emitted from the surface of the solid in a time around 10 -16 second. The H(+) depends on the incident charge state g-i. When using slow ions (keV) the same dependence was observed for the first time and compared to the fast ion results. The equilibrum charge state of fast ions passing through solids was measured. The influence of the angle of incidence was investigated. Langmuir-Blodgett films of fatty acid were used. A geometrical model is developed for the 50 angstroms layer [fr

  6. Optical Spectra Tuning of All-Glass Photonic Bandgap Fiber Infiltrated with Silver Fast-Ion-Conducting Glasses

    Directory of Open Access Journals (Sweden)

    Ioannis Konidakis

    2014-08-01

    Full Text Available Silver iodide metaphosphate glasses of the xAgI + (1−xAgPO3 family are embedded inside the air capillaries of a commercial silica photonic crystal fiber (PCF by means of vacuum-assisted infiltration technique. In this paper, we report on tuning the photonic bandgap (PBG guidance characteristics of the fabricated all-glass photonic bandgap fibers, by varying the composition of the fast-ion-conducting phosphate glass infiltration medium. Doping AgPO3 metaphosphate glass with AgI significantly alters the PBG guidance patterns in the examined range between 350 and 1750 nm, as it leads to the introduction of numerous additional transmission stop-bands, while affecting scattering dependant losses. The effect of phosphate glass cooling method during sample fabrication on the transmission behavior of the xAgI + (1−xAgPO3/PCFs is also considered.

  7. Optical Spectra Tuning of All-Glass Photonic Bandgap Fiber Infiltrated with Silver Fast-Ion-Conducting Glasses.

    Science.gov (United States)

    Konidakis, Ioannis; Pissadakis, Stavros

    2014-08-07

    Silver iodide metaphosphate glasses of the x AgI + (1- x )AgPO₃ family are embedded inside the air capillaries of a commercial silica photonic crystal fiber (PCF) by means of vacuum-assisted infiltration technique. In this paper, we report on tuning the photonic bandgap (PBG) guidance characteristics of the fabricated all-glass photonic bandgap fibers, by varying the composition of the fast-ion-conducting phosphate glass infiltration medium. Doping AgPO₃ metaphosphate glass with AgI significantly alters the PBG guidance patterns in the examined range between 350 and 1750 nm, as it leads to the introduction of numerous additional transmission stop-bands, while affecting scattering dependant losses. The effect of phosphate glass cooling method during sample fabrication on the transmission behavior of the x AgI + (1- x )AgPO₃/PCFs is also considered.

  8. Poly(ethylene oxide) : succinonitrile-a polymeric matrix for fast-ion conducting redox-couple solid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ravindra Kumar; Kim, Hyun-Min; Rhee, Hee-Woo, E-mail: hwrhee@sogang.ac.kr [Department of Chemical and Biomolecular Engineering, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742 (Korea, Republic of)

    2011-05-25

    A blend of poly(ethylene oxide), PEO, and succinonitrile, SN, was investigated for the first time for applying it as a polymeric matrix of low-cost and thermally stable fast-ion conducting redox-couple solid polymer electrolytes. The PEO-SN blend in equal weight fraction showed room temperature ionic conductivity of 1 x 10{sup -8} S cm{sup -1} with nearly two orders of magnitude higher than that of PEO due to reduced crystallinity. The blend resulted in a solid electrolyte with improved ionic conductivity of {approx}7 x 10{sup -4} S cm{sup -1} at 25 deg. C. The blend and its electrolyte showed thermal stability up to 100 deg. C, which is essential for outdoor application of dye-sensitized solar cells.

  9. Electron interference in fast ion collisions with H{sub 2} and the frequency parameter

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, S; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Fainstein, P D, E-mail: lokesh@tifr.res.in [Centro Atomico Bariloche, 8400 Bariloche (Argentina)

    2011-06-15

    The Young-type interference effect has been investigated in electron emission from molecular hydrogen in collision of 5 MeV u{sup -1} F{sup 9+} ions. The double differential cross section ratios of molecular-to-atomic hydrogen exhibits oscillatory structure, which is discussed in terms of the Young-type electron interference. We have obtained the frequencies of such oscillation for different angles. A comparative study of the frequency parameter is given with early measurements performed by other groups.

  10. Real-time diagnostics of fast light ion beams accelerated by a sub-nanosecond laser

    Czech Academy of Sciences Publication Activity Database

    Margarone, Daniele; Krása, Josef; Picciotto, A.; Prokůpek, Jan

    2011-01-01

    Roč. 56, č. 2 (2011), s. 137-141 ISSN 0029-5922 R&D Projects: GA ČR(CZ) GAP205/11/1165 EU Projects: European Commission(XE) 212105 - ELI-PP Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-driven acceleration * ion beams * real-time diagnostics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.389, year: 2011 http://www.nukleonika.pl/www/back/full/vol56_2011/v56n2p137f.pdf

  11. Radiative double-electron capture in collisions of fast heavy ions with solid carbon targets

    International Nuclear Information System (INIS)

    Yakhontov, V.L.; Amusia, M.Y.

    1997-01-01

    Two-electron capture with an emission of a single photon (TESP) in collisions of highly charged ions with light atoms is considered. Such a process is actually a time-reversed double photoionization but occurring at specific kinematics. In the lowest order in the interelectron interaction, the TESP probability is determined by two diagrams which are evaluated analytically by means of the Coulomb Green close-quote s function. The calculated ratio of the radiative double-electron capture and single recombination cross sections is in fair agreement with the data obtained in the recent experimental study of this phenomenon. copyright 1997 The American Physical Society

  12. Radiative double electron capture in fast heavy ion-atom collisions

    International Nuclear Information System (INIS)

    Yakhontov, V.L.; Amusia, M.Ya.

    1996-01-01

    Two-electron capture with emission of a single photon (TESP) in collisions of highly charged ions with light atoms is considered. Such a process is actually a time-reversed double photoionization but occurring at specific kinematics. In the lowest order in the inter-electron interaction, the TESP probability is determined by two diagrams which are evaluated analytically by means of the Coulomb Green function. The calculated ratio of the TESP and single recombination cross sections is in fair agreement with the data obtained in the recent experimental study of this phenomena. (orig.)

  13. Identification of an Actual Strain-Induced Effect on Fast Ion Conduction in a Thin-Film Electrolyte.

    Science.gov (United States)

    Ahn, Junsung; Jang, Ho Won; Ji, Hoil; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Kim, Byung-Kook; Lee, Hae-Weon; Lee, Jong-Ho

    2018-04-11

    Strain-induced fast ion conduction has been a research area of interest for nanoscale energy conversion and storage systems. However, because of significant discrepancies in the interpretation of strain effects, there remains a lack of understanding of how fast ionic transport can be achieved by strain effects and how strain can be controlled in a nanoscale system. In this study, we investigated strain effects on the ionic conductivity of Gd 0.2 Ce 0.8 O 1.9-δ (100) thin films under well controlled experimental conditions, in which errors due to the external environment could not intervene during the conductivity measurement. In order to avoid any interference from perpendicular-to-surface defects, such as grain boundaries, the ionic conductivity was measured in the out-of-plane direction by electrochemical impedance spectroscopy analysis. With varying film thickness, we found that a thicker film has a lower activation energy of ionic conduction. In addition, careful strain analysis using both reciprocal space mapping and strain mapping in transmission electron microscopy shows that a thicker film has a higher tensile strain than a thinner film. Furthermore, the tensile strain of thicker film was mostly developed near a grain boundary, which indicates that intrinsic strain is dominant rather than epitaxial or thermal strain during thin-film deposition and growth via the Volmer-Weber (island) growth mode.

  14. Characterization of graphite etched with potassium hydroxide and its application in fast-rechargeable lithium ion batteries

    Science.gov (United States)

    Shim, Jae-Hyun; Lee, Sanghun

    2016-08-01

    Surface-modified graphite for application as an anode material in lithium ion batteries was obtained by etching with KOH under mild conditions without high-temperature annealing. The surface of the etched graphite is covered with many nano-sized pores that act as entrances for lithium ions during the charging process. As compared with pristine graphite and other references such as pitch-coated or etched graphite samples with annealing, our non-annealed etched graphite exhibits excellent electrochemical properties, particularly at fast charging rates of over 2.5 C. While avoidance of the trade-off between increase of irreversible capacity and good rate capability has previously been a main concern in highly porous carbonaceous materials, we show that the slightly larger surface area created by the etching does not induce a significant increase of irreversible capacity. This study shows that it is important to limit the size of pores to the nanometer scale for excellent battery performance, which is possible by etching under relatively mild conditions.

  15. Double differential distribution of electron emission in the ionization of water molecules by fast bare oxygen ions

    Science.gov (United States)

    Bhattacharjee, Shamik; Biswas, Shubhadeep; Bagdia, Chandan; Roychowdhury, Madhusree; Nandi, Saikat; Misra, Deepankar; Monti, J. M.; Tachino, C. A.; Rivarola, R. D.; Champion, C.; Tribedi, Lokesh C.

    2016-03-01

    The doubly differential distributions of low-energy electron emission in the ionization of water molecules under the impact of fast bare oxygen ions with energy of 48 MeV are measured. The measured data are compared with two quantum-mechanical models, i.e. the post and prior versions of the continuum distorted wave-eikonal initial state (CDW-EIS) approximation, and the first-order Born approximation with initial and final wavefunctions verifying correct boundary conditions (CB1). An overall excellent qualitative agreement is found between the data and the CDW-EIS models whereas the CB1 model showed substantial deviation. However, the detailed angular distributions display some discrepancies with both CDW-EIS models. The single differential and total cross-sections exhibit good agreement with the CDW-EIS models. The present detailed data set could also be used as an input for modeling highly charged ion induced radiation damage in living tissues, whose most abundant component is water. Similar measurements are also carried out for a projectile energy of 60 MeV. However, since the double differential cross-section data show similar results the details are not provided here, except for the total ionization cross-sections results.

  16. Online Measurement of Exhaled NO Concentration and Its Production Sites by Fast Non-equilibrium Dilution Ion Mobility Spectrometry

    Science.gov (United States)

    Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Liu, Jiwei; Li, Haiyang

    2016-03-01

    Exhaled nitric oxide (NO) is one of the most promising breath markers for respiratory diseases. Its profile for exhalation and the respiratory NO production sites can provide useful information for medical disease diagnosis and therapeutic procedures. However, the high-level moisture in exhaled gas always leads to the poor selectivity and sensitivity for ion spectrometric techniques. Herein, a method based on fast non-equilibrium dilution ion mobility spectrometry (NED-IMS) was firstly proposed to directly monitor the exhaled NO profile on line. The moisture interference was eliminated by turbulently diluting the original moisture to 21% of the original with the drift gas and dilution gas. Weak enhancement was observed for humid NO response and its limit of detection at 100% relative humidity was down to 0.58 ppb. The NO concentrations at multiple exhalation flow rates were measured, while its respiratory production sites were determined by using two-compartment model (2CM) and Högman and Meriläinen algorithm (HMA). Last but not the least, the NO production sites were analyzed hourly to tentatively investigate the daily physiological process of NO. The results demonstrated the capacity of NED-IMS in the real-time analysis of exhaled NO and its production sites for clinical diagnosis and assessment.

  17. 3D inverse-opal structured Li4Ti5O12 Anode for fast Li-Ion storage capabilities

    Science.gov (United States)

    Kim, Dahye; Quang, Nguyen Duc; Hien, Truong Thi; Chinh, Nguyen Duc; Kim, Chunjoong; Kim, Dojin

    2017-11-01

    Since the demand for high power Li-ion batteries (LIBs) is increasing, spinel-structured lithium titanate, Li4Ti5O12 (LTO), as the anode material has attracted great attention because of its excellent cycle retention, good thermal stability, high rate capability, and so on. However, LTO shows relatively low conductivity due to empty 3 d orbital of Ti4+ state. Nanoscale architectures can shorten electron conduction path, thus such low electronic conductivity can be overcome while Li+ can be easily accessed due to large surface area. Herein, three dimensional bicontinuous LTO electrodes were prepared via close-packed self-assembly with polystyrene (PS) spheres followed by removal of them, which leads to no blockage of Li+ ion transportation pathways as well as fast electron conduction. 3D bicontinuous LTO electrodes showed high-rate lithium storage capability (103 mAh/g at 20 C), which is promising as the power sources that require rapid electrochemical response.[Figure not available: see fulltext.

  18. Development of sustained release fast-disintegrating tablets using various polymer-coated ion-exchange resin complexes.

    Science.gov (United States)

    Jeong, Seong Hoon; Park, Kinam

    2008-04-02

    Complex formation between drugs and ion-exchange resins was investigated and the effects of coating by various aqueous polymeric dispersions on the complexes were evaluated for developing new sustained-release fast-disintegrating tablets (FDTs). Complexes of ion-exchange resin and dextromethorphan, a model drug, were prepared using different particle sizes of the resins. Aqueous colloidal dispersions of ethylcellulose (EC) and poly(vinyl acetate) (Kollicoat SR30D) were used for fluid-bed coating. Based on drug loading, release profiles, and scanning electron microscopy (SEM) images, the coated particles were granulated with suitable tablet excipients and then compressed into the tablets. Drug release profiles and SEM pictures were compared before and after the manufacturing processes. As the particle size of resins increased, the drug loading and release rate decreased due to the reduced effective diffusion coefficient and surface area. Higher coating level decreased the release rate further. In contrast to EC, Kollicoat SR30D coated particles could be compressed into tablets without any rupture or cracks on the coating since the mechanical properties of the polymer was more resistant to the manufacturing processes. This resulted in no significant changes in release rates. SEM showed the mechanical strength of the polymers affected the morphological change after compression. When the drug release profiles were applied into Boyd model and Higuchi equation, the linear relationship was observed, indicating that the diffusion within the resin matrix is the rate-controlling step.

  19. Effects of fast ions and an external inductive electric field on the neoclassical parallel flow, current, and rotation in general toroidal systems

    International Nuclear Information System (INIS)

    Nakajima, Noriyoshi; Okamoto, Masao.

    1992-05-01

    Effects of external momentum sources, i.e., fast ions produced by the neutral beam injection and an external inductive electric field, on the neoclassical ion parallel flow, current, and rotation are analytically investigated for a simple plasma in general toroidal systems. It is shown that the contribution of the external sources to the ion parallel flow becomes large as the collision frequency of thermal ions increases because of the momentum conservation of Coulomb collisions and sharply decreasing viscosity coefficients, with collision frequency. As a result, the beam-driven parallel flow of thermal ions becomes comparable to that of electrons in the Pfirsh-Schluter collisionality regime, whereas in the 1/μ or banana regime it is smaller than that of electrons by the order of √(m e /m i ) (m e and m i are electron and ion masses). This beam-driven ion parallel flow can not produce a large beam-driven current because of the cancellation with electron parallel flow, but produces a large toroidal rotation of ions. As both electrons and ions approach the Pfirsh-Schluter collisionality regime the contribution of thermodynamical forces becomes negligibly small and the large toroidal rotation of ions is predominated by the beam-driven component in the non-axisymmetric configuration with large helical ripples. (author)

  20. Measurement of the radial density distribution of the light emissions near the trajectory of fast ions in nitrogen

    International Nuclear Information System (INIS)

    Ibach, T.

    1983-11-01

    For the analysis of the emission and deceleration mechanisms of ionisation-electrons (delta-electrons) during the passage of fast ions through gases, the radial density distribution of the light emission has been measured, which is related with the (0,0)-transitions of two optical bands in nitrogen. These measurements have been made using a small aperture limited ion beam. The first band under study is the 2. positive system at 337.1 nm excited mainly by low energy electrons around 20 eV, and the second band is the 1. negative system at 391.4 nm excited by fast electrons with simultaneous ionisation. For these measurements an experimental setup has been developed with a telescope-like optical system and interference filters to detect the emitted light with a high spacial resolution (4x10 -4 of profile width) and a high dynamic range (10 6 ). The experiments have been performed using proton beams of different energies between 270 keV and 2.8 MeV, He-3 beams with 270 keV/u and 500 keV/u and a Ne beam with 270 keV/u with gas pressures in the range between 0.133 to 13.3 mbar. Based on the method of Abel inversion the spacial light emission density is deduced from the experimental distance functions and normalized to a gas density of 1 g/cm 3 . The results show that approximately half of the total light emission in the 1. negative system and the ionisation is caused by the primary interaction of the ion beam. For the same energy per nucleon this contribution decreases relative to the contribution of the delta-electrons with increasing atomic number. In addition the delta-radiation becomes harder with increasing atomic number. Good agreement is obtained by comparison with the results of other authors, which are based on probe techniques and Monte-Carlo-calculations. (orig./HP) [de

  1. Fast and Accurate Measurement of Entropy Profiles of Commercial Lithium-Ion Cells

    International Nuclear Information System (INIS)

    Osswald, Patrick J.; Rosario, Manuel del; Garche, Jürgen; Jossen, Andreas; Hoster, Harry E.

    2015-01-01

    We report on an effective approach to speed up the measurement of thermodynamic characterization curves (entropy of reaction Δ r S(x)) of rechargeable batteries, in particular commercial 18650 lithium ion cells. We propose and demonstrate a measurement and data processing protocol that reduces the time required to record entropy profiles from time scales of weeks to time scales of hours – without loss in accuracy. For time consuming studies such as investigations on ageing of battery cells, entropy profile measurements thus become as feasible as conventional electrochemical characterisation techniques like dV/dQ or cyclic voltammetry. We demonstrate this at the examples of two ageing protocols applied to a commercial high power and a commercial high energy cell, respectively: (i) accelerated calendric aging by storing cells at 100% state of charge at 60 °C and (ii) continuous cycling with a 1C current at 25 °C

  2. Modification and characterization of cellulose cotton fibers for fast extraction of some precious metal ions.

    Science.gov (United States)

    Monier, M; Akl, M A; Ali, Wael M

    2014-05-01

    In this work, native cellulose cotton fibers were first modified through graft copolymerization of polyacrylonitrile (PAN) and then by insertion of phenyl thiosemicarbazide moieties to finally produce C-PTS chelating fibers, which were fully characterized using various instrumental techniques such as SEM, FTIR, EDX and XRD spectra. The obtained C-PTS were employed in removal and extraction of Au(3+), Pd(2+) and Ag(+) precious metal ions from their aqueous solutions using batch experiments. The kinetic studies showed that the pseudo-second-order model exhibited the best fit for the experimental data. In addition, the adsorption isotherm studies indicated that the adsorption follows the Langmuir model and the maximum adsorption capacities for Au(3+), Pd(2+) and Ag(+) were 198.31, 87.43 and 71.14 mg/g respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Interference effects in double ionization of spatially aligned hydrogen molecules by fast highly charged ions

    International Nuclear Information System (INIS)

    Landers, A.L.; Alnaser, A.S.; Tanis, J.A.; Wells, E.; Osipov, T.; Carnes, K.D.; Ben-Itzhak, I.; Cocke, C.L.; McGuire, J.H.

    2004-01-01

    Cross sections differential in target orientation angle were measured for 19 MeV F 8+ +D 2 collisions. Multihit position-sensitive detectors were used to isolate the double-ionization channel and determine a posteriori the full momentum vectors of both ejected D + fragments. A strong dependence of the double ionization cross section on the angle between the incident ion direction and the target molecular axis is observed with a ≅3.5:1 enhancement for molecules aligned perpendicular to the projectile axis. This clear asymmetry is attributed to interference effects, analogous to Young's two-slit experiment, arising from coherent contributions to the ionization from both atomic centers. The data are compared to a simple scattering model based on two center interference

  4. Nanoconfined LiBH4 as a Fast Lithium Ion Conductor

    DEFF Research Database (Denmark)

    Blanchard, Didier; Nale, Angeloclaudio; Sveinbjörnsson, Dadi Þorsteinn

    2015-01-01

    Designing new functional materials is crucial for the development of efficient energy storage and conversion devices such as all solid-state batteries. LiBH 4 is a promising solid electrolyte for Li-ion batteries. It displays high lithium mobility, although only above 110 °C at which a transition......O2. Solid state 7Li NMR confirmed that the high conductivity can be attributed to a very high Li+ mobility in the solid phase at room temperature. Confinement of LiBH4 in the pores leads also to a lower solid-solid phase transition temperature than for bulk LiBH4. However, the high ionic mobility...

  5. RADIOLYSIS OF NITROGEN AND WATER-ICE MIXTURE BY FAST IONS: IMPLICATIONS FOR KUIPER BELT OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Barros, A. L. F. de [Departamento de Física, Centro Federal de Educação Tecnológica Celso Suckow da Fonseca, Av. Maracanã 229, 20271-110 Rio de Janeiro, RJ (Brazil); Silveira, E. F da [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900, Rio de Janeiro, RJ (Brazil); Bergantini, A. [Universidade do Vale do Paraiba, Av. Shishima Hifumi, 2911 Urbanova, São José do Campos, SP (Brazil); Rothard, H.; Boduch, P. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP-GANIL (CEA-CNRS-ENSICAEN-UCBN), BP 5133, Boulevard Henri Becquerel, F-14070 Caen Cedex 05 (France)

    2015-09-10

    The participation of condensed nitrogen in the surface chemistry of some objects in the outer solar system, such as Pluto and Triton, is very important. The remote observation of this species using absorption spectroscopy is a difficult task because N{sub 2} is not IR active in the gas phase. Water is also among the most abundant molecules in the surface of these objects; chemical reactions between N{sub 2} and H{sub 2}O induced by cosmic rays are therefore expected. Although pure N{sub 2} ice is hardly identified by IR spectroscopy, the species produced through the processing of the surface ice by cosmic rays may give relevant clues indicating how abundant the N{sub 2} is in the outside layers of the surface of trans-Neptunian objects (TNOs). The objective of this work is to investigate the formation of nitrogenated species induced by cosmic-ray analogs in an ice mixture containing nitrogen and water. Experiments were performed in the GANIL Laboratory by bombarding N{sub 2}:H{sub 2}O (10:1) ice at 15 K with 40 MeV {sup 58}Ni{sup 11+} ions. Evolution of precursor and daughter species was monitored by Fourier transform infrared spectrometry. The main produced species are the nitrogen oxides NO{sub k} (k = 1–3), N{sub 2}O{sub j} (j = 1–5), N{sub 3}, and O{sub 3}. Among them, the N{sub 2}O and N{sub 3} are the most abundant, representing ∼61% of the total column density of the daughter molecules at 10{sup 13} ions cm{sup −2} fluence; the current results indicate that the yield of daughter species from this mixture is low, and this may be one of the reasons why N{sub i}O{sub j} molecules are not usually observed in TNOs.

  6. RADIOLYSIS OF NITROGEN AND WATER-ICE MIXTURE BY FAST IONS: IMPLICATIONS FOR KUIPER BELT OBJECTS

    International Nuclear Information System (INIS)

    Barros, A. L. F. de; Silveira, E. F da; Bergantini, A.; Rothard, H.; Boduch, P.

    2015-01-01

    The participation of condensed nitrogen in the surface chemistry of some objects in the outer solar system, such as Pluto and Triton, is very important. The remote observation of this species using absorption spectroscopy is a difficult task because N 2 is not IR active in the gas phase. Water is also among the most abundant molecules in the surface of these objects; chemical reactions between N 2 and H 2 O induced by cosmic rays are therefore expected. Although pure N 2 ice is hardly identified by IR spectroscopy, the species produced through the processing of the surface ice by cosmic rays may give relevant clues indicating how abundant the N 2 is in the outside layers of the surface of trans-Neptunian objects (TNOs). The objective of this work is to investigate the formation of nitrogenated species induced by cosmic-ray analogs in an ice mixture containing nitrogen and water. Experiments were performed in the GANIL Laboratory by bombarding N 2 :H 2 O (10:1) ice at 15 K with 40 MeV 58 Ni 11+ ions. Evolution of precursor and daughter species was monitored by Fourier transform infrared spectrometry. The main produced species are the nitrogen oxides NO k (k = 1–3), N 2 O j (j = 1–5), N 3 , and O 3 . Among them, the N 2 O and N 3 are the most abundant, representing ∼61% of the total column density of the daughter molecules at 10 13 ions cm −2 fluence; the current results indicate that the yield of daughter species from this mixture is low, and this may be one of the reasons why N i O j molecules are not usually observed in TNOs

  7. Yolk-shell structured composite for fast and selective lithium ion sieving.

    Science.gov (United States)

    Li, Na; Lu, Deli; Zhang, Jinlong; Wang, Lingzhi

    2018-06-15

    Yolk-shell structured C@Li 4 Ti 5 O 12 microspheres composed of carbon core (ca. 500 nm) and sea urchin-like Li 4 Ti 5 O 12 shell (ca. 400-500 nm) are formed by hydrothermally treating the core-shell structured C@TiO 2 in the EtOH/H 2 O solution of LiOH and calcining it in N 2 atmosphere. Yolk-shell structured TiO 2 -type lithium ion sieve is further transformed from C@Li 4 Ti 5 O 12 through the acid treatment, which have a high specific surface area of 201.74 m 2 /g. The composite shows adsorption capacity towards Li + proportional to the pH value in the range of 7-13. The adsorption reaches equilibrium within 2 h with a high equilibrium adsorption capacity of 28.46 mg/g under alkaline conditions, which is ca. 8 times the value of ordinary TiO 2 lithium ion sieve with comparable size and surface area, demonstrating the enhanced adsorption is attributed to the generation of more accessible surficial voids by replacing internal part with light carbon core. The adsorption follows Freundlich and pseudo-second-order kinetic models with a high rate constant of 0.015 g/(mg·min). The selective adsorption to Li + is verified in the presence of K + , Na + , Ca 2+ and Mg 2+ . Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Measurement of the space potential of a high-temperature plasma by fast atomic beam scattering on an ion probe beam

    Energy Technology Data Exchange (ETDEWEB)

    Kabantsev, A. A.; Taskayev, S. Yu. [AN SSSR, Novosibirsk (USSR). Inst. Yadernoj Fiziki

    1988-06-01

    In this work we carry out an analysis of the possibility of measuring the potential distribution of a high-temperature plasma by scattering fast atoms on an ion probe beam. The proposed method is based on the idea of determining the energy of the ion beam, which depends on the plasma potential, from the energy spectrum of the scattered atoms. Application of this method allows one to avoid a number of fundamental difficulties characteristic of plasma potential measurements which make use of heavy-ion probe beams. 34 refs., 1 fig.

  9. Measurement of the space potential of a high-temperature plasma by fast atomic beam scattering on an ion probe beam

    International Nuclear Information System (INIS)

    Kabantsev, A.A.; Taskayev, S.Yu.

    1989-01-01

    In this work we carry out an analysis of the possibility of measuring the potential distribution of a high-temperature plasma by scattering fast atoms on an ion probe beam. The proposed method is based on the idea of determining the energy of the ion beam, which depends on the plasma potential, from the energy spectrum of the scattered atoms. Application of this method allows one to avoid a number of fundamental difficulties characteristic of plasma potential measurements which make use of heavy-ion probe beams. 34 refs., 1 fig

  10. Activation of ion implanted Si for backside processing by Ultra-fast Laser Thermal Annealing: Energy homogeneity and micro-scale sheet resistance

    DEFF Research Database (Denmark)

    Huet, K.; Lin, Rong; Boniface, C

    2009-01-01

    In this paper ion activation of implanted silicon using ultra-fast laser thermal annealing (LTA) process was discussed. The results stated that there was high dopant activation using LTA process for over 70%, excellent within shot activation uniformity, and there was a possibility for overlap...

  11. Fast, Statistical Model of Surface Roughness for Ion-Solid Interaction Simulations and Efficient Code Coupling

    Science.gov (United States)

    Drobny, Jon; Curreli, Davide; Ruzic, David; Lasa, Ane; Green, David; Canik, John; Younkin, Tim; Blondel, Sophie; Wirth, Brian

    2017-10-01

    Surface roughness greatly impacts material erosion, and thus plays an important role in Plasma-Surface Interactions. Developing strategies for efficiently introducing rough surfaces into ion-solid interaction codes will be an important step towards whole-device modeling of plasma devices and future fusion reactors such as ITER. Fractal TRIDYN (F-TRIDYN) is an upgraded version of the Monte Carlo, BCA program TRIDYN developed for this purpose that includes an explicit fractal model of surface roughness and extended input and output options for file-based code coupling. Code coupling with both plasma and material codes has been achieved and allows for multi-scale, whole-device modeling of plasma experiments. These code coupling results will be presented. F-TRIDYN has been further upgraded with an alternative, statistical model of surface roughness. The statistical model is significantly faster than and compares favorably to the fractal model. Additionally, the statistical model compares well to alternative computational surface roughness models and experiments. Theoretical links between the fractal and statistical models are made, and further connections to experimental measurements of surface roughness are explored. This work was supported by the PSI-SciDAC Project funded by the U.S. Department of Energy through contract DOE-DE-SC0008658.

  12. Induction of aberrations in human lymphocytes by γ-rays and fast heavy ions

    International Nuclear Information System (INIS)

    Govorun, R.D.; Repin, M.V.; Krasavin, E.A.; Lukasova, E.; Kozubek, S.; Kroha, V.

    1998-01-01

    Frequencies of aberrations induced by different doses of γ-rays and 14 N ions (LET ∼ 77 keV/μm) in the chromosomes 1 and 2 of human lymphocytes as detected by FISH were compared with those detected by conventional staining in the whole genome. The results have shown that the induction of aberrations in the chromosomes 1 and 2 is more frequent than that in the rest of genome. The frequencies of dicentrics detected by FISH in the chromosomes 1 and 2 recalculated for the whole genome are in good agreement with those detected by conventional staining at different doses of 14 N, but they are about 2 times lower at low doses of γ-rays. Translocation frequencies calculated in the same manner from the frequencies induced in the chromosome 1 by γ-rays correspond to the frequencies of dicentrics detected by conventional staining, however, they are about 2 times higher than those detected by convectional staining at doses lower than 2 Gy of 14 N. The differences between the frequencies of these aberration types increase at higher doses of both radiation types

  13. Stripline fast faraday cup for measuring GHz structure of ion beams

    International Nuclear Information System (INIS)

    Bogaty, J.M.

    1992-01-01

    This patent describes an apparatus for measuring the structure on ion beams. It comprises a dielectric strip with an opening therethrough to create an air gap from one side of the dielectric strip to the other; a conductive stripeline bonded to one side of the dielectric strip and a groundplane bonded to the opposing side of the dielectric strip wherein the airgap remains open; a thin dielectric film coating the groundplane; a second groundplane adhering to the thin dielectric film wherein a portion of the thin dielectric film adjacent to the air gap is exposed; a fine mesh electrostatic screen bonded to the second groundplane directly over the air gap; means for matching the impedance at the electrostatic screen with that of the stripline; a Faraday cup mounted opposite the electrostatic screen with a drift space between the electrostatic screen and the Faraday cup; means for reducing RF reflections from the stripline through the use of a terminating impedance; means for biasing the electrostatic screen; means for outputting information to an amplifier; and a measuring device coupled to the amplifier where the measuring device receives information from the amplifier

  14. Impact parameter dependence of inner-shell vacancy production in fast ion--atom collisions

    International Nuclear Information System (INIS)

    Randall, R.R.

    1975-01-01

    The impact parameter dependence of the probability for production of K x rays has been measured for oxygen projectiles on copper, chlorine projectiles on aluminum, titanium and copper, and carbon and fluorine projectiles on argon at scaled velocities near 0.5. The O + Cu data was taken at incident energies of 1.56, 1.88 and 2.69 MeV/amu for the O bombardment of thin Cu foils. The Cl ions had incident energies of 0.6 and 0.85 MeV/amu upon thin foils of Al, Ti, and Cu. A thin Ar gas target was used for 1.58 MeV/amu C and F beams, permitting measurements to be made for charge-pure C 4+ , C 6+ , F 5+ and F 9+ projectiles. Cu, Cl and Ar K x rays were observed with a Si(Li) detector and scattered particles were counted using a masked surface-barrier detector. Comparison of the shapes of the measured probability curves with predictions of the semiclassical Coulomb approximation (SCA) shows adequate agreement for the O + Cu system. For the higher ratio of projectile to target nuclear charge (Z 1 /Z 2 ) of the Cl + Al, Ti, Cu and C, F + Ar systems, the SCA and Brinkman--Kramers (BK) model for charge transfer fail to predict the measured curves. In particular, the SCA and BK fail to account for large vacancy production probabilities at large impact parameters (larger than the Slater-screened Bohr radii of the K electrons). Further, the dependence of the shapes of the measured curves on the charge state of the incident projectile is pronounced for the cases having the larger Z 1 /Z 2 values. Alternative models are discussed in an attempt to account for the observed behavior

  15. Electrical properties of fast ion conducting silver based borate glasses: Application in solid battery

    International Nuclear Information System (INIS)

    Masoud, Emad M.; Khairy, M.; Mousa, M.A.

    2013-01-01

    Graphical abstract: -- Highlights: •AgI dopant created more opened borate network structure. •Dielectric constant and loss values increased with AgI concentration. •AgI dopant enhanced both ion migration and orientation. •0.6 AgI–0.27 Ag 2 O–0.13 B 2 O 3 showed the highest DC-conductivity at room temperature. •It showed also good life time as a solid electrolyte in solid battery at room temperature. -- Abstract: The electrical properties of the ternary ionic conducting glass system xAgI–(1 – x)[0.67Ag 2 O–0.33B 2 O 3 ], where x = 0.4 , 0.5, 0.6, 0.7 and 0.8, were studied for emphasizing the influence of silver iodide concentration on the transport properties in the based borate glasses. The glasses were prepared by melt quenching technique and characterized using X-ray diffraction (XRD), FT-IR spectra and differential thermal analysis (DTA). XRD confirmed a glassy nature for all investigated compositions. Electrical conductivity (σ), dielectric constant (ε′), dielectric loss (ε ″ ) and impedance spectra (Z′–Z′′) were studied for all samples at a frequency range of 0–10 6 Hz and over a temperature range of 303–413 K. Changes of conductivity and dielectric properties with composition, temperature and frequency were analyzed and discussed. A silver iodine battery using glassy electrolyte sample with the highest ionic conductivity (x = 0.6) was studied

  16. Interaction between fast ions and ion cyclotron heating in a tokamak plasma; Interaction des ions rapides avec les ondes a la frequence cyclotronique ionique dans un plasma de tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bergeaud, V

    2001-11-01

    In an ignited fusion reactor, the plasma temperature is sustained by the fusion reactions. However, before this regime is reached, it is necessary to bring an additional power to the plasma. One of the methods that enables the coupling of power is the use of an electromagnetic wave in the ion cyclotron range of frequencies (ICRF). This thesis deals with the interaction between ICRF heating and the fast ions. The thesis contains a theoretical study of the influence of ICRF heating on the ion distribution function. A particular emphasis is put on the importance of the toroidal spectrum of the modes of propagation of the wave in the tokamak. It is necessary to take into account all these modes in order to correctly assess the strength of the wave particle interaction, especially for high energy particles (of the order of hundreds of keV). The classical treatment of the wave particle interaction is based on the hypothesis that the cyclotron phase of the particle and the wave phase are de-correlated between successive resonant interactions. One is therefore led to consider ICRF heating as a diffusive process. This hypothesis is reconsidered in this thesis and it is shown that strong correlations exist in a large part of the velocity space. For this study, a numerical code that computes the full trajectory of particles interacting with a complete electromagnetic field has been developed. The thesis also deals with the problem of fast ion losses due to the breaking of the toroidal symmetry of the confinement magnetic field (called the ripple modulation). Between two toroidal coils, local magnetic wells exist, and particles can be trapped there. When trapped they undergo a vertical drift that makes them quit the plasma rapidly. The ripple modulation also causes an enhancement of the radial diffusion, thereby increasing the losses. A Monte Carlo model describing these mechanisms is presented. This model is validated thanks to a comparison with an experimental database from

  17. Interaction of fast ions with ion cyclotron electromagnetic waves in tokamak plasma; Interaction des ions rapides avec les ondes a la frequence cyclotronique ionique dans un plasma de tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bergeaud, V

    2000-12-01

    In an ignited fusion reactor, the plasma temperature is sustained by the fusion reactions. However, before this regime is reached, it is necessary to bring an additional power to the plasma. One of the methods that enables the coupling of power is the use of an electromagnetic wave in the ion cyclotron range of frequencies (ICRF). This thesis deals with the interaction between ICRF heating and the fast ions. The thesis contains a theoretical study of the influence of ICRF heating on the ion distribution function. A particular emphasis is put on the importance of the toroidal spectrum of the modes of propagation of the wave in the tokamak. It is necessary to take into account all these modes in order to correctly assess the strength of the wave particle interaction, especially for high energy particles (of the order of hundreds of keV). The classical treatment of the wave particle interaction is based on the hypothesis that the cyclotron phase of the particle and the wave phase are de-correlated between successive resonant interactions. One is therefore led to consider ICRF heating as a diffusive process. This hypothesis is reconsidered in this thesis and it is shown that strong correlations exist in a large part of the velocity space. For this study, a numerical code that computes the full trajectory of particles interacting with a complete electromagnetic field has been developed. The thesis also deals with the problem of fast ion losses due to the breaking of the toroidal symmetry of the confinement magnetic field (called the ripple modulation). Between two toroidal coils, local magnetic wells exist, and particles can be trapped there. When trapped they undergo a vertical drift that makes them quit the plasma rapidly. The ripple modulation also causes an enhancement of the radial diffusion, thereby increasing the losses. A Monte Carlo model describing these mechanisms is presented. This model is validated thanks to a comparison with an experimental database from

  18. Modeling of neutron emission spectroscopy in JET discharges with fast tritons from (T)D ion cyclotron heating

    International Nuclear Information System (INIS)

    Tardocchi, M.; Gorini, G.; Andersson Sunden, E.; Conroy, S.; Ericsson, G.; Gatu Johnson, M.; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Kaellne, J.; Ronchi, E.; Sjoestrand, H.; Weiszflog, M.; Johnson, T.; Lamalle, P. U.

    2006-01-01

    The measurement of fast ion populations is one of the diagnostic capabilities provided by neutron emission spectroscopy (NES). NES measurements were carried out during JET trace tritium campaign with the magnetic proton recoil neutron spectrometer. A favorable plasma scenario is (T)D where the resulting 14 MeV neutron yield is dominated by suprathermal emission from energetic tritons accelerated by radio frequency at their fundamental cyclotron frequency. Information on the triton distribution function has been derived from NES data with a simple model based on two components referred to as bulk (B) and high energy (HE). The HE component is based on strongly anisotropic tritium distribution that can be used for routine best-fit analysis to provide tail temperature values (T HE ). This article addresses to what extent the T HE values are model dependent by comparing the model above with a two-temperature (bi-) Maxwellian model featuring parallel and perpendicular temperatures. The bi-Maxwellian model is strongly anisotropic and frequently used for radio frequency theory

  19. A Position Sensitive, Highly Radiation Hard and Fast Hadron Calorimeter for a Lead Ion Experiment at CERN SPS

    CERN Document Server

    Dellacasa, G; Gallio, M; Guaita, P; Musso, A; Piccotti, A; Scomparin, E; Vercellin, Ermanno; Chiavassa, E

    1995-01-01

    We present the performance of the Zero Degree Calorimeter (ZDC) built for the NA50 experiment at the CERN SPS. This detector measures the Cherenkov light produced in silica optical fibres embedded in tantalum and offers the double advantage of being highly radiation resistant (up to several Grads) and very fast (signal width of the order of 10 ns). It has an active volume of 5x5x65 cm3 with a fibre to tantalum volume ratio 1/17; the fibres are positioned at an angle of 0¡ with respect to the beam direction and have a diameter of 365µm. The measured energy resolution (s/E) is: 30% for protons at 205 GeV and 5% for lead ions at 160 GeV/nucleon. The detector exhibits also very good localising properties since it can detect the impact point of the lead beam on its front face with a precision better than 0.4mm rms.

  20. Real-Time linux dynamic clamp: a fast and flexible way to construct virtual ion channels in living cells.

    Science.gov (United States)

    Dorval, A D; Christini, D J; White, J A

    2001-10-01

    We describe a system for real-time control of biological and other experiments. This device, based around the Real-Time Linux operating system, was tested specifically in the context of dynamic clamping, a demanding real-time task in which a computational system mimics the effects of nonlinear membrane conductances in living cells. The system is fast enough to represent dozens of nonlinear conductances in real time at clock rates well above 10 kHz. Conductances can be represented in deterministic form, or more accurately as discrete collections of stochastically gating ion channels. Tests were performed using a variety of complex models of nonlinear membrane mechanisms in excitable cells, including simulations of spatially extended excitable structures, and multiple interacting cells. Only in extreme cases does the computational load interfere with high-speed "hard" real-time processing (i.e., real-time processing that never falters). Freely available on the worldwide web, this experimental control system combines good performance. immense flexibility, low cost, and reasonable ease of use. It is easily adapted to any task involving real-time control, and excels in particular for applications requiring complex control algorithms that must operate at speeds over 1 kHz.

  1. Defect interactions with stepped CeO₂/SrTiO₃ interfaces: implications for radiation damage evolution and fast ion conduction.

    Science.gov (United States)

    Dholabhai, Pratik P; Aguiar, Jeffery A; Misra, Amit; Uberuaga, Blas P

    2014-05-21

    Due to reduced dimensions and increased interfacial content, nanocomposite oxides offer improved functionalities in a wide variety of advanced technological applications, including their potential use as radiation tolerant materials. To better understand the role of interface structures in influencing the radiation damage tolerance of oxides, we have conducted atomistic calculations to elucidate the behavior of radiation-induced point defects (vacancies and interstitials) at interface steps in a model CeO2/SrTiO3 system. We find that atomic-scale steps at the interface have substantial influence on the defect behavior, which ultimately dictate the material performance in hostile irradiation environments. Distinctive steps react dissimilarly to cation and anion defects, effectively becoming biased sinks for different types of defects. Steps also attract cation interstitials, leaving behind an excess of immobile vacancies. Further, defects introduce significant structural and chemical distortions primarily at the steps. These two factors are plausible origins for the enhanced amorphization at steps seen in our recent experiments. The present work indicates that comprehensive examination of the interaction of radiation-induced point defects with the atomic-scale topology and defect structure of heterointerfaces is essential to evaluate the radiation tolerance of nanocomposites. Finally, our results have implications for other applications, such as fast ion conduction.

  2. A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sutcliffe, G. D., E-mail: gdsut@mit.edu; Milanese, L. M.; Orozco, D.; Lahmann, B.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Park, H.-S.; Rygg, J. R.; Casey, D. T.; Bionta, R.; Turnbull, D. P.; Huntington, C. M.; Ross, J. S. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Zylstra, A. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rosenberg, M. J.; Glebov, V. Yu. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States)

    2016-11-15

    CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

  3. A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

    Science.gov (United States)

    Sutcliffe, G. D.; Milanese, L. M.; Orozco, D.; Lahmann, B.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Park, H.-S.; Rygg, J. R.; Casey, D. T.; Bionta, R.; Turnbull, D. P.; Huntington, C. M.; Ross, J. S.; Zylstra, A. B.; Rosenberg, M. J.; Glebov, V. Yu.

    2016-11-01

    CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

  4. A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

    International Nuclear Information System (INIS)

    Sutcliffe, G. D.; Milanese, L. M.; Orozco, D.; Lahmann, B.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Park, H.-S.; Rygg, J. R.; Casey, D. T.; Bionta, R.; Turnbull, D. P.; Huntington, C. M.; Ross, J. S.; Zylstra, A. B.; Rosenberg, M. J.; Glebov, V. Yu.

    2016-01-01

    CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

  5. A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sutcliffe, G. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Milanese, L. M. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Orozco, D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Lahmann, B. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Gatu Johnson, M. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Séguin, F. H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Sio, H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Frenje, J. A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Li, C. K. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Park, H. -S. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Rygg, J. R. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Casey, D. T. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Bionta, R. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Turnbull, D. P. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Huntington, C. M. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Ross, J. S. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Zylstra, A. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Rosenberg, M. J. [Laboratory for Laser Energetics, Rochester, New York 14623, USA; Glebov, V. Yu. [Laboratory for Laser Energetics, Rochester, New York 14623, USA

    2016-08-05

    CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

  6. Main Design Principles of the Cold Beam Pipe in the FastRamped Superconducting Accelerator Magnets for Heavy Ion Synchrotron SIS100

    Science.gov (United States)

    Mierau, A.; Schnizer, P.; Fischer, E.; Macavei, J.; Wilfert, S.; Koch, S.; Weiland, T.; Kurnishov, R.; Shcherbakov, P.

    SIS100, the world second large scale heavy ion synchrotron using fast ramped superconducting magnets, is to be built at FAIR. Its high current operation of intermediate charge state ions requires stable vacuum pressures technological feasible design solutions, three opposite requirements have to be met: minimum magnetic field distortion caused by AC losses, mechanical stability and low and stable wall temperatures of the beam pipe. We present the possible design versions of the beam pipe for the high current curved dipole. The pros and cons of these proposed designs were studied using simplified analytical models, FEM calculations and tests on models.

  7. Measurements of the fast-ion distribution function at ASDEX upgrade by collective Thomson scattering (CTS) using active and passive views

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Stejner Pedersen, Morten; Rasmussen, Jesper

    2015-01-01

    Collective Thomson scattering (CTS) can provide measurements of the confined fast-ion distribution function resolved in space, time and 1D velocity space. On ASDEX Upgrade, the measured spectra include an additional signal which previously has hampered data interpretation. A new set-up using two......, the measured spectra agree quantitatively with the synthetic spectra in periods with and without NBI heating. For the discharges investigated, the central velocity distribution of neutral beam ions can be described by classical slowing down. These results will have a major impact on ITER physics exploration...

  8. Fast Acceleration of ``Killer'' Electrons and Energetic Ions by Interplanetary Shock Stimulated ULF Waves in the Inner Magnetosphere

    Science.gov (United States)

    Zong, Q.

    2010-12-01

    Energetic electrons and ions in the Van Allen radiation belt are the number one space weather threat. How the energetic particles are accelerated in the Van Allen radiation belts is one of major problems in the space physics. Very Low Frequency (VLF) wave-particle interaction has been considered as one of primary electron acceleration mechanisms because electron cyclotron resonances can easily occur in the VLF frequency range. However, recently, by using four Cluster spacecraft observations, we have found that after interplanetary shocks impact on the Earth’s magnetosphere, the acceleration of the energetic electrons in the radiation belt started nearly immediately and lasted for a few hours. The time scale (a few days) for traditional acceleration mechanism of VLF wave-particle interaction, as proposed by Horne et al. [1], to accelerate electrons to relativistic energies is too long to explain the observations. It is further found that interplanetary shocks or solar wind pressure pulses with even small dynamic pressure change can play a non-negligible role in the radiation belt dynamics. Interplanetary shocks interact with and the Earth’s magnetosphere manifests many fundamental important space physics phenomena including energetic particle acceleration. The mechanism of fast acceleration of energetic electrons in the radiation belt response to interplanetary shock impact contains three contributing parts: (1) the initial adiabatic acceleration due to the strong shock-related magnetic field compression; (2) then followed by the drift-resonant acceleration with poloidal ULF waves excited at different L-shells; and (3) particle acceleration due to fast damping electric fields associated with ULF waves. Particles will have a net acceleration since particles in the second half circle will not lose all of the energy gained in the first half cycle. The results reported in this paper cast new lights on understanding the acceleration of energetic particles in the

  9. Fluorescent switch for fast and selective detection of mercury (II) ions in vitro and in living cells and a simple device for its removal.

    Science.gov (United States)

    Yuan, Yue; Jiang, Shenlong; Miao, Qingqing; Zhang, Jia; Wang, Mengjing; An, Linna; Cao, Qinjingwen; Guan, Yafeng; Zhang, Qun; Liang, Gaolin

    2014-07-01

    A water-soluble, biocompatible, and fluorescent chemosensor (1) for label-free, simple, and fast detection of mercury ions (Hg(2+)) in aqueous solutions and in HepG2 cells with high selectivity is reported herein. Chelation of 1 with Hg(2+) results in the disappearance of its fluorescence emission at 350 nm and the appearance of a new emission at 405 nm. Selectivity and interference studies indicated that 1 could be selectively chelated by Hg(2+) without interference from other metal ions. Insight into the mechanisms responsible for its fluorescence effect was gained from ultrafast transient absorption spectroscopy. With these properties, 1 was successfully applied for imaging Hg(2+) in living cells and for removing Hg(2+) from river water. Moreover, we also constructed a simple device for fast and effective removal of Hg(2+) from contaminated liquid samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Exit points, on plasma, of lost fast ions during NBI in TJ-II; Puntos de salida en el plasma de los iones rapidos durante NBI en el TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.

    1995-07-01

    The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between, the position of those exit points and the corresponding at birth, orbits and drifts is analysed also. It is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II. (Author) 2 refs.

  11. A robustness analysis method with fast estimation of dose uncertainty distributions for carbon-ion therapy treatment planning.

    Science.gov (United States)

    Sakama, Makoto; Kanematsu, Nobuyuki; Inaniwa, Taku

    2016-08-07

    A simple and efficient approach is needed for robustness evaluation and optimization of treatment planning in routine clinical particle therapy. Here we propose a robustness analysis method using dose standard deviation (SD) in possible scenarios such as the robustness indicator and a fast dose warping method, i.e. deformation of dose distributions, taking into account the setup and range errors in carbon-ion therapy. The dose warping method is based on the nominal dose distribution and the water-equivalent path length obtained from planning computed tomography data with a clinically commissioned treatment planning system (TPS). We compared, in a limited number of scenarios at the extreme boundaries of the assumed error, the dose SD distributions obtained by the warping method with those obtained using the TPS dose recalculations. The accuracy of the warping method was examined by the standard-deviation-volume histograms (SDVHs) for varying degrees of setup and range errors for three different tumor sites. Furthermore, the influence of dose fractionation on the combined dose uncertainty, taking into consideration the correlation of setup and range errors between fractions, was evaluated with simple equations using the SDVHs and the mean value of SDs in the defined volume of interest. The results of the proposed method agreed well with those obtained with the dose recalculations in these comparisons, and the effectiveness of dose SD evaluations at the extreme boundaries of given errors was confirmed from the responsivity and DVH analysis of relative SD values for each error. The combined dose uncertainties depended heavily on the number of fractions, assumed errors and tumor sites. The typical computation time of the warping method is approximately 60 times less than that of the full dose calculation method using the TPS. The dose SD distributions and SDVHs with the fractionation effect will be useful indicators for robustness analysis in treatment planning, and the

  12. Benchmark of multi-phase method for the computation of fast ion distributions in a tokamak plasma in the presence of low-amplitude resonant MHD activity

    Science.gov (United States)

    Bierwage, A.; Todo, Y.

    2017-11-01

    The transport of fast ions in a beam-driven JT-60U tokamak plasma subject to resonant magnetohydrodynamic (MHD) mode activity is simulated using the so-called multi-phase method, where 4 ms intervals of classical Monte-Carlo simulations (without MHD) are interlaced with 1 ms intervals of hybrid simulations (with MHD). The multi-phase simulation results are compared to results obtained with continuous hybrid simulations, which were recently validated against experimental data (Bierwage et al., 2017). It is shown that the multi-phase method, in spite of causing significant overshoots in the MHD fluctuation amplitudes, accurately reproduces the frequencies and positions of the dominant resonant modes, as well as the spatial profile and velocity distribution of the fast ions, while consuming only a fraction of the computation time required by the continuous hybrid simulation. The present paper is limited to low-amplitude fluctuations consisting of a few long-wavelength modes that interact only weakly with each other. The success of this benchmark study paves the way for applying the multi-phase method to the simulation of Abrupt Large-amplitude Events (ALE), which were seen in the same JT-60U experiments but at larger time intervals. Possible implications for the construction of reduced models for fast ion transport are discussed.

  13. Study of the Hamiltonian of the response of a tokamak plasma to the ion cyclotron heating wave: minor heating and generation of current by a fast wave

    International Nuclear Information System (INIS)

    Becoulet, A.

    1990-06-01

    The role of additional heatings, such as the ion Cyclotron heating, is to raise magnetic fusion plasmas to higher temperatures, to satisfy the ignition condition. The understanding of the wave absorption mechanisms by the plasma requires a precise description of the particle individual trajectories. The Hamiltonian mechanics, through action-angle variables, allows this description, and makes the computation of the wave-particle interaction easier. A quantitative evaluation of the intrinsic stochasticity is derived for ionic trajectories perturbated by the fast wave. The results show the importance of the Hamiltonian chaos in the formation of the deeply anisotropic distribution tails, encountered in minor heating scenarios. Direct interaction of the electrons and the fast wave is analysed. The influence of the various parameters is examined in order to optimize this scenario of fast wave current drive in tokamaks [fr

  14. SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

    Science.gov (United States)

    Gardés, E.; Balanzat, E.; Ban-d'Etat, B.; Cassimi, A.; Durantel, F.; Grygiel, C.; Madi, T.; Monnet, I.; Ramillon, J.-M.; Ropars, F.; Lebius, H.

    2013-02-01

    We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/μm. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.

  15. Penta-graphene: A Promising Anode Material as the Li/Na-Ion Battery with Both Extremely High Theoretical Capacity and Fast Charge/Discharge Rate.

    Science.gov (United States)

    Xiao, Bo; Li, Yan-Chun; Yu, Xue-Fang; Cheng, Jian-Bo

    2016-12-28

    Recently, a new two-dimensional (2D) carbon allotrope named penta-graphene was theoretically proposed ( Zhang , S. ; et al. Proc. Natl. Acad. Sci. U.S.A. 2015 , 112 , 2372 ) and has been predicted to be the promising candidate for broad applications due to its intriguing properties. In this work, by using first-principles simulation, we have further extended the potential application of penta-graphene as the anode material for a Li/Na-ion battery. Our results show that the theoretical capacity of Li/Na ions on penta-graphene reaches up to 1489 mAh·g -1 , which is much higher than that of most of the previously reported 2D anode materials. Meanwhile, the calculated low open-circuit voltages (from 0.24 to 0.60 V), in combination with the low diffusion barriers (≤0.33 eV) and the high electronic conductivity during the whole Li/Na ions intercalation processes, further show the advantages of penta-graphene as the anode material. Particularly, molecular dynamics simulation (300 K) reveals that Li ion could freely diffuse on the surface of penta-graphene, and thus the ultrafast Li ion diffusivity is expected. Superior performance of penta-graphene is further confirmed by comparing with the other 2D anode materials. The light weight and unique atomic arrangement (with isotropic furrow paths on the surface) of penta-graphene are found to be mainly responsible for the high Li/Na ions storage capacity and fast diffusivity. In this regard, except penta-graphene, many other recently proposed 2D metal-free materials with pentagonal Cairo-tiled structures may be the potential candidates as the Li/Na-ion battery anodes.

  16. Fast calculator for X-ray emission due to Radiative Recombination and Radiative Electron Capture in relativistic heavy-ion atom collisions

    Science.gov (United States)

    Herdrich, M. O.; Weber, G.; Gumberidze, A.; Wu, Z. W.; Stöhlker, Th.

    2017-10-01

    In experiments with highly charged, fast heavy ions the Radiative Recombination (RR) and Radiative Electron Capture (REC) processes have significant cross sections in an energy range of up to a few GeV / u . They are some of the most important charge changing processes in collisions of heavy ions with atoms and electrons, leading to the emission of a photon along with the formation of the ground and excited atomic states. Hence, for the understanding and planning of experiments, in particular for X-ray spectroscopy studies, at accelerator ring facilities, such as FAIR, it is crucial to have a good knowledge of these cross sections and the associated radiation characteristics. In the frame of this work a fast calculator, named RECAL, for the RR and REC process is presented and its capabilities are demonstrated with the analysis of a recently conducted experiment at the Experimental Storage Ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. A method is presented to determine unknown X-ray emission cross sections via normalization of the recorded spectra to REC cross sections calculated by RECAL.

  17. Multi-phase simulation of fast ion profile flattening due to Alfvén eigenmodes in a DIII-D experiment

    International Nuclear Information System (INIS)

    Todo, Y.; Van Zeeland, M.A.; Bierwage, A.; Heidbrink, W.W.

    2014-01-01

    A multi-phase simulation that is a combination of classical simulation and hybrid simulation for energetic particles interacting with a magnetohydrodynamic (MHD) fluid is developed to simulate the nonlinear dynamics on the slowing down time scale of the energetic particles. The hybrid simulation code is extended with realistic beam deposition profile, collisions and losses, and is used for both the classical and hybrid phases. The code is run without MHD perturbations in the classical phase, while the interaction between the energetic particles and the MHD fluid is simulated in the hybrid phase. In a multi-phase simulation of DIII-D discharge #142111, the stored beam ion energy is saturated due to Alfvén eigenmodes (AE modes) at a level lower than in the classical simulation. After the stored fast ion energy is saturated, the hybrid simulation is run continuously. It is demonstrated that the fast ion spatial profile is significantly flattened due to the interaction with the multiple AE modes with amplitude v/v A  ∼ δB/B ∼ O(10 −4 ). The dominant AE modes are toroidal Alfvén eigenmodes (TAE modes), which is consistent with the experimental observation at the simulated moment. The amplitude of the temperature fluctuations brought about by the TAE modes is of the order of 1% of the equilibrium temperature. This is also comparable with electron cyclotron emission measurements in the experiment. (paper)

  18. Development of Pseudocapacitive Properties in Nanostructured LiMn2O4 as a Fast Charging Cathode for Lithium Ion Batteries

    Science.gov (United States)

    Lesel, Benjamin

    Pseudocapacitive materials provide a high energy density solution to fast charging, long cycle life energy storage. This work explores the pseudocapacitive characteristics and attempts to optimize nanostructured LiMn2O 4 for use as a cathode material in fast charging, long cycle lifetime lithium ion batteries. Because slow kinetics in traditional batteries is linked to long lithium ion diffusion lengths through micron sized grains, the key to achieving pseudocapacitance in most materials is through nanostructuring to reduced diffusion distance. One of the most effective methods for producing nanostructures is through nanocrystal/polymer templating, which produces a porous structure with interconnected nanoscale walls capable of intercalating lithium ions at pseudocapactive rates. To make a full pseudocapacitive lithium ion battery a reality, however, a pseudocapacitive material of each electrode type, anode and cathode, must be paired. To date, many pseudocapacitive materials have been identified, but nearly all of them are redox active in a voltage range more suitable for anode materials. Recently, we identified a pseudocapacitive cathode material, nanostructured LiMn2O4 which shows impressive rate capabilities. Unfortunately, the improvements came at the cost of energy density, which decreased significantly with decreasing crystallite size. Kinetics for different crystallite sizes, however, increased suddenly below a certain critical crystallite size. We found that this critical crystallite size, below which pseudocapacitance occurred, was linked to a suppression of phase transition in nanoscale LiMn2O4. To address the capacity loss due to dissolution in high surface area nanostructured LiMn 2O4 powders, a sol-gel templating method which formed dissolution resistant surfaces was employed. The resulting materials had long needle-like morphology and showed higher capacity and less dissolution than a similarly sized material synthesized with a different structure

  19. ions

    African Journals Online (AJOL)

    (MP2 B2). In order to draw the final conclusion about the content of the isomers of pentaatomic ions in saturated vapor over cesium chloride, we have taken into account the entropy factor. We considered the isomerization reactions which are given below: Cs3Cl2. + (V-shaped) = Cs3Cl2. + (cyclic or bipyramidal). (1). Cs2Cl3.

  20. Relation between the swelling and the disordering in ionic crystals irradiated by fast heavy ions; Relation entre le gonflement et la creation de defauts dans les cristaux ioniques irradies par des ions lourds rapides

    Energy Technology Data Exchange (ETDEWEB)

    Boccanfuso, M

    2001-12-01

    When fast heavy ions penetrate in matter, they slow down essentially by depositing their energy on the electrons. This can lead to strong electronic excitation densities in the solid and then to structural modifications. In this work, calcium fluoride (CaF{sub 2}) was used to look further into the damage induced by irradiation with fast heavy ions in ionic crystals. Four techniques were mainly employed to characterise this damage. These techniques of analysis are wide angle X-ray diffraction, surface profilometry, Rutherford backscattering spectrometry and UV-visible optical absorption spectroscopy. The results of this work show that CaF{sub 2} answers in a multiple way to the electronic excitations. For stopping powers higher than approximately 5 keV/nm, a polygonization seems to occur. This causes a structural disorder, a swelling of 0.27 % and the formation of fractures in the material. A second damage mechanism is caused above approximately 13 keV/nm and results in a loss of the initial crystalline structure. However, optical centres appear whatever the ion stopping power, which indicates that these defects cannot be the cause of the two above mentioned damage mechanisms. According to a thermal spike model, the two thresholds can be linked to melting and sublimation energy of the material, respectively. (author)

  1. Charge Deep Level Transient Spectroscopy Study of 3\\div7 MeV/amu Ion and Fast Neutron Irradiation-Induced Changes in Mos Structures

    CERN Document Server

    Stano, J; Ziska, M

    2001-01-01

    Radiation-induced changes in MOS capacitor structures irradiated with Bi (710 MeV), Kr (245 MeV), Ar (280, 155 MeV) ions and fast neutrons (E>0.1 MeV) have been studied in view of Q-DLTS and C-V techniques. As was found, high energy ion and neutron irradiation enhance the induction of positive charge density in the oxide layer of MOS samples. The number of electrically active defects in this layer strongly decreases under dense electronic excitations. No dependence of vacancy-oxygen center concentration in silicon substrate normalized per number of displaced atoms by nuclear elastic collisions on projectile type have been observed.

  2. Rapid identification and quantitation of compounds with forensic interest using fast liquid chromatography-ion trap mass spectrometry and library searching.

    Science.gov (United States)

    Pihlainen, Katja; Sippola, Erkki; Kostiainen, Risto

    2003-04-25

    A fast liquid chromatography-electrospray tandem mass spectrometric (LC-ESI-MS-MS) method by using a monolithic column, gradient elution and ion trap mass spectrometer was developed for 14 forensically interesting and chemically different compounds. All compounds were eluted within 2.5 min and the total analysis time was 5 min including stabilisation time required for the next injection. All the compounds, basics, neutrals and acids were efficiently ionised by positive ion ESI. A laboratory library including MS-MS spectra and retention times was developed and tested. Results with 476 standard samples and 50 authentic samples showed that the compounds studied can be unambiguously identified with the library. A quantitative method was developed for the compounds using external calibration. The evaluation process showed good linearity of the method and reasonable repeatability. Limits of detection ranged from 10.0 to 50.0 ng/ml.

  3. Modification and characterization of PET fibers for fast removal of Hg(II), Cu(II) and Co(II) metal ions from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Abdel-Latif, D.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

    2013-04-15

    Highlights: ► PET fibers were graft copolymerized with acrylonitrile. ► Further modification was carried out through the reaction with hydrazine hydrate and then potassium thiocyanate. ► The resulted chelating fibers were characterized by various instrumental methods. ► The fibers were applied to remove Hg{sup 2+}, Cu{sup 2+} and Co{sup 2+} from aqueous solutions. -- Abstract: A new chelating fiber (PET-TSC) was prepared with PET for fast removal of Hg{sup 2+}, Cu{sup 2+} and Co{sup 2+} from water. Elemental analysis, SEM, BET surface area, {sup 13}C NMR, FTIR and X-ray diffraction spectra were used to characterize PET-TSC. The higher uptake capacity of the studied metal ions was observed at higher pH values. Kinetic study indicated that the adsorption of Hg{sup 2+}, Cu{sup 2+} and Co{sup 2+} followed the pseudo-second-order equation, suggesting chemical sorption as the rate-limiting step of the adsorption process. The best interpretation for the equilibrium data was given by Langmuir isotherm, and the maximum adsorption capacities were 120.02, 96.81 and 78.08 mg/g for Hg{sup 2+}, Cu{sup 2+} and Co{sup 2+} ions, respectively. 1 M HCl or 0.1 M EDTA could be used as effective eluant to desorb the Hg{sup 2+}, Cu{sup 2+} and Co{sup 2+} adsorbed by PET-TSC, and the adsorption capacity of PET-TSC for the three heavy metal ions could still be maintained at about 90% level at the 5th cycle. Accordingly, it is expected that PET-TSC could be used as a promising adsorbent for fast removal of heavy metal ions from water, and the present work also might provide a simple and effective method to reuse the waste PET fibers.

  4. Intercalating Ti2Nb14O39Anode Materials for Fast-Charging, High-Capacity and Safe Lithium-Ion Batteries.

    Science.gov (United States)

    Lin, Chunfu; Deng, Shengjue; Kautz, David J; Xu, Zhihao; Liu, Tao; Li, Jianbao; Wang, Ning; Lin, Feng

    2017-12-01

    Ti-Nb-O binary oxide materials represent a family of promising intercalating anode materials for lithium-ion batteries. In additional to their excellent capacities (388-402 mAh g -1 ), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti-Nb-O family, Ti 2 Nb 14 O 39 , as an advanced anode material. Ti 2 Nb 14 O 39 porous spheres (Ti 2 Nb 14 O 39 -S) exhibit a defective shear ReO 3 crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li + -ion transport length and fast Li + -ion diffusivity. Consequently, the Ti 2 Nb 14 O 39 -S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g -1 at 0.1 C), high first-cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li + ), outstanding rate capability (223 mAh g -1 at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti 2 Nb 14 O 39 -S can be a promising anode material for fast-charging, high capacity, safe and stable lithium-ion batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Angle-differential observation of plasmon electrons in the double-differential cross-section spectra of fast-ion-induced electron ejection from C60

    Science.gov (United States)

    Kelkar, A. H.; Gulyás, L.; Tribedi, Lokesh C.

    2015-11-01

    We report on the measurement of double-differential distribution of soft electron emission from C60 fullerene, induced by a fast-moving Coulomb field of 76 MeV energy bare fluorine ions. A broad "plasmon-electron" peak, riding on the Coulomb-ionization continuum, is observed due to the deexcitation of the giant dipole plasmon resonance state in C60. The angular distribution of the plasmon electrons goes through a dip around 90°, which is contrary to that observed in ion-atom collisions measured in situ, indicating the alignment of the induced dipole moment along the projectile beam direction. A model based on the photoelectron angular distribution which is modified due to the ion-induced postcollisional interaction provides an excellent agreement with the observed asymmetric distribution. The distribution smoothly changes from a dip at 90° to a peak with the variation of ejected electron energy indicating transition from a collective plasmon behavior of the whole system to a single ion-atom interaction. The single-differential cross section was also derived, which preserves the signature of the collective excitation.

  6. Measurements of high energy loss rates of fast highly charged U ions channeled in thin silicon crystals

    International Nuclear Information System (INIS)

    Ray, C.; Chevallier, M.; Dauvergne, D.; Poizat, J.-C.; Testa, E.; Braeuning-Demian, A.; Braeuning, H.; Kozhuharov, C.; Liesen, D.; Stoehlker, Th.; Cohen, C.; L'Hoir, A.; Mokler, P. H.; Toulemonde, M.

    2011-01-01

    The results of two channeling experiments show that highly charged heavy ions at moderate velocities (v 0 ) may lose more energy in the traversal of a thin crystal when they are injected along a major crystallographic direction than when they traverse the crystal in random conditions. This is due to the fact that the large reduction of electron capture probabilities allows them to keep their high electronic charge throughout the crystal, which is not the case for projectiles traveling in random conditions. Although channeled projectiles experience reduced electron densities, their energy loss rate, that is, at first order, proportional to the square of the ions charge, is then strongly enhanced. This feature could be used as a step for decelerating highly charged ions from the high energies that are needed to produce them, and also to improve our understanding of the slowing down of very highly charged projectiles at low velocities, for which the current perturbative models are not well suited.

  7. Study on initial stage of hetero-epitaxial growth by glancing angle scattering of fast ions from surfaces

    International Nuclear Information System (INIS)

    Fujii, Yoshikazu; Toba, Kazuaki; Narumi, Kazumasa; Kimura, Kenji; Mannami, Michihiko

    1993-01-01

    Initial stages of epitaxial growth of lead chalcogenides on the (100) surface of SnTe under UHV conditions are studied from the angular distribution of scattered ions at glancing angle incidence of 0.7 MeV He ions on the growing surfaces. Real time measurement of the angular distribution is performed during the growth. Anomalous broadening of the angular distribution is observed at the initial stage of the growth. The broadening is attributed to the surface wrinkles induced by a square network of misfit edge dislocations. (author)

  8. Hamiltonian study of the response of a tokamak plasma to the ion cyclotron heating wave: minor heating and current generation by the fast wave

    International Nuclear Information System (INIS)

    Becoulet, A.

    1990-06-01

    The role of additional Heatings, such as the Ion Cyclotron Heating, is to raise magnetic fusion plasmas to higher temperatures, to satisfy the ignition condition. The understanding of the wave absorption mechanisms by the plasma first requires a precise description of the particle individual trajectories. The Hamiltonian mechanics, through action-angle variables, allows this description, and makes the computation of the wave-particle interaction easier. We then derive a quantitative evaluation of the intrinsic stochasticity for ionic trajectories perturbated by the fast wave. This stochasticity, combinated to the collisional effects, gives the validity domain for a quasilinear approximation of the evolution equation. This equation is then written under a variational formulation, and solved semi-analytically. Results conclude to the importance of the Hamiltonian chaos in the formation of the deeply anisotropic distribution tails, encountered in minority heating scenarios. Direct interaction of the electrons and the fast wave is similarly analysed. The influence of the various parameters (wave spectrum, magnetic configuration, frequency,...) is then examined in order to optimize this scenario of fast wave current drive in tokamaks [fr

  9. A Novel Active Online State of Charge Based Balancing Approach for Lithium-Ion Battery Packs during Fast Charging Process in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiudong Cui

    2017-11-01

    Full Text Available Abstract: Non-uniformity of Lithium-ion cells in a battery pack is inevitable and has become the bottleneck to the pack capacity, especially in the fast charging process. Therefore, a balancing approach is essentially required. This paper proposes an active online cell balancing approach in a fast charging process using the state of charge (SOC as balancing criterion. The goal of this approach is to complete pack balancing within the limited charging time. An adaptive extended Kalman filter (AEKF is applied to estimate the pack cell SOC during the charging process to obtain accurate results under modeling errors and measurement noises. To implement the proposed AEKF, only one additional current sensor is required to obtain the current of each cell required for the SOC estimation. An experimental platform is established to verify the effectiveness of the proposed approach. The results show that the proposed balancing approach with the SOC as a balancing criterion can overcome the challenges of non-uniformity and flat voltage plateau and charge more capacity into a LiFePO4 battery pack than those with the terminal voltage as a balancing criterion in the fast charging process.

  10. A fast cavity dumper for a picosecond glass laser

    Science.gov (United States)

    Oak, S. M.; Bindra, K. S.; Narayan, B. S.; Khardekar, R. K.

    1991-02-01

    A fast cavity dumper for picosecond glass laser has been made. The optical and electrical characterization of the cavity dumper is described. An avalanche transistor Marx bank generator drives the cavity dumper. Up to 5 kV peak amplitude and 1.5 ns fall time negative polarity step pulses are generated by the Marx bank circuit. With a capacitive load like Pockels cell the pulse fall time increases to 4 ns. Optical switching times as fast as 2 ns (10%-90%) are experimentally measured. The contrast ratio of 1000 is obtained after a double pass through an amplifier. Single picosecond pulses are produced with an energy jitter of 10%.

  11. Design and measurements of a fast high-voltage pulse generator for the MedAustron Low Energy Transfer line fast deflector

    CERN Document Server

    Fowler, T; Mueller, F; Kramer, T; Stadlbauer, T

    2012-01-01

    MedAustron, a centre for ion-therapy and research, will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment. The Low Energy Beam Transfer line (LEBT) to the synchrotron contains an electrostatic fast deflector (EFE) which, when energized, deviates the continuous beam arriving from the ion source onto a Faraday Cup: the specified voltage is ±3.5 kV. De-energizing the EFE for variable pulse durations from 500 ns up to d.c. allows beam passage for multi-turn injection into the synchrotron. To maintain beam quality in the synchrotron, the EFE pulse generator requires rise and fall times of less than 300 ns between 90 % of peak voltage and a ±1 V level. To achieve this, a pulsed power supply (PKF), with high voltage MOSFET switches connected in a push-pull configuration, will be mounted in close proximity to the deflector itself. A fast, large dynamic range monitoring circuit will verify switching to the ±1 V level and subsequent flat bottom pu...

  12. Effects of the radial electric field on the confinement of trapped fast ions in the Wendelstein 7-X and Helias reactor

    Science.gov (United States)

    Kolesnichenko, Ya. I.; Lutsenko, V. V.; Tykhyy, A. V.; Weller, A.; Werner, A.; Wobig, H.; Geiger, J.

    2006-07-01

    Confinement of trapped fast ions in the Wendelstein-line stellarators in the presence of the radial electric field, Er, is studied. It is shown that negative electric field improves the confinement; in particular, a radially localized field can play the role of a transport barrier for the ions escaping from the plasma when Er=0. In contrast to this, the positive electric field tends to deteriorate the ion confinement, unless its magnitude is very large. Such a field accompanied by the plasma rotation with the frequency around a certain magnitude, which we refer to as the resonance rotation frequency, leads to a quick particle loss. A possibility of using the plasma rotation with the resonance frequency for the ash removal in a Helias reactor is considered. The mentioned results are obtained analytically and numerically. The analytical consideration was done on the basis of the derived bounce-averaged equations of the particle motion. The numerical calculations were carried out for Wendelstein 7-X [G. Grieger et al., J. Plasma Fusion Res. Series 1, 53 (1998)] and a Helias reactor [J. Kisslinger et al., Proceedings of the 17th International Conference, Yokohama, 1998 (1999), Vol. 4, p. 1239] by the guiding center code ORBIS (ORBits In Stellarators) developed in this work.

  13. Li + secondary ion energy distributions probed by fast N 2+ and N q+ bombardment of LiF

    Science.gov (United States)

    Pereira, J. A. M.; da Silveira, E. F.

    1998-12-01

    The time-of-flight method was employed to measure the energy distributions of secondary ions emitted from LiF thin film targets. A van de Graaff generator was used to accelerate N2+ and Nq+ particles to energies in the range of 75 keV to 7.5 MeV in order to bombard the sample. The Li+ secondary ion emission presents contributions due to nuclear and electronic sputtering which could be studied independently. The nuclear sputtering contribution, for projectile energies above 0.50 MeV/atom, does not play a significant role and the corresponding differential yield is well described through the linear collision cascade theory. It is observed that the Li+ electronic sputtering yield is strongly correlated with the number of atomic constituents in the projectile while its energy distribution is not. Furthermore, the Li+ kinetic energy of emission is not sensitive to variations on the velocity and on the charge state of the primary ion, leading to a general conclusion that the Li+ energy distribution due to the electronic sputtering does not depend strongly on the electronic stopping power of the primary ion. The Li+ maximum axial emission energy produced by the electronic sputtering process is observed to be Ez ∼ 10 eV. A model based on hot hole diffusion and multiple hole localization on the surface was developed in order to calculate the Li+ energy distribution, providing good agreement with experimental values.

  14. Bi1−xNbxO1.5+x (x=0.0625, 0.12) fast ion conductors: Structures, stability and oxide ion migration pathways

    International Nuclear Information System (INIS)

    Tate, Matthew L.; Hack, Jennifer; Kuang, Xiaojun; McIntyre, Garry J.; Withers, Ray L.; Johnson, Mark R.; Radosavljevic Evans, Ivana

    2015-01-01

    A combined experimental and computational study of Bi 1−x Nb x O 1.5+x (x=0.0625 and 0.12) has been carried out using laboratory X-ray, neutron and electron diffraction, impedance measurements and ab-initio molecular dynamics. We demonstrate that Bi 0.9375 Nb 0.0625 O 1.5625 , previously reported to adopt a cubic fluorite-type superstructure, can form two different polymorphs depending on the synthetic method: a metastable cubic phase is produced by quenching; while slower cooling yields a stable material with a tetragonal √2×√2×1 superstructure, which undergoes a reversible phase transition into the cubic form at ~680 °C on subsequent reheating. Neutron diffraction reveals that the tetragonal superstructure arises mainly from ordering in the oxygen sublattice, with Bi and Nb remaining disordered, although structured diffuse scattering observed in the electron diffraction patterns suggests a degree of short-range ordering. Both materials are oxide ion conductors. On thermal cycling, Bi 0.88 Nb 0.12 O 1.62 exhibits a decrease in conductivity of approximately an order of magnitude due to partial transformation into the tetragonal phase, but still exhibits conductivity comparable to yttria-stabilised zirconia (YSZ). Ab-initio molecular dynamics simulations performed on Bi 0.9375 Nb 0.0625 O 1.5625 show that oxide ion diffusion occurs by O 2− jumps between edge- and corner-sharing OM 4 groups (M=Bi, Nb) via tetrahedral □M 4 and octahedral □M 6 vacancies. - Graphical abstract: Oxide ion migration in tetragonal Bi 0.9375 Nb 0.0625 O 1.5625 occurs by O 2− jumps between edge- and corner-sharing OM 4 groups (M=Bi, Nb) via tetrahedral M 4 and octahedral M 6 vacancies. - Highlights: • Bi 0.9375 Nb 0.0625 O 1.5625 adopts a tetragonal √2×√2×1 fluorite superstructure. • Superstructure is due to ordering in the O-sublattice, with Bi/Nb disordered. • Bi 0.9375 Nb 0.0625 O 1.5625 is a good oxide ion conductor. • O 2− jump between OM 4 groups (M

  15. Polystyrene Sulfonate Threaded through a Metal-Organic Framework Membrane for Fast and Selective Lithium-Ion Separation.

    Science.gov (United States)

    Guo, Yi; Ying, Yulong; Mao, Yiyin; Peng, Xinsheng; Chen, Banglin

    2016-11-21

    Extraction of lithium ions from salt-lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST-1 metal-organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST-1-6.7, with unique anchored three-dimensional sulfonate networks, shows a very high Li + conductivity of 5.53×10 -4  S cm -1 at 25 °C, 1.89×10 -3  S cm -1 at 70 °C, and Li + flux of 6.75 mol m -2  h -1 , which are five orders higher than that of the pristine HKUST-1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li + , Na + , K + , and Mg 2+ ions to the sulfonate groups, the PSS@HKUST-1-6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li + /Na + , Li + /K + , Li + /Mg 2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li + extraction membranes. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Young Type Interference Effect on the Forward-Backward Asymmetry Parameter in Electron Emission from H2 Under Fast Ion Impact

    Science.gov (United States)

    Misra, Deepankar; Kelkar, A. H.; Tribedi, Lokesh C.

    2007-09-01

    We have investigated the double differential distribution of electron emission from molecular hydrogen in collisions with fast bare carbon ions in order to investigate the effect of Young type interference on the forward-backward angular asymmetry. The asymmetry parameter, derived from the cross sections for complementary forward and backward angles, shows an oscillatory behaviour as a function of electron velocity which is absent in atomic target such as He. It is shown that the asymmetry parameter which is based on the DDCS of H2 only, can be used as self normalizing way of the obtaining the Young type interference in an inversion symmetric homo-nuclear diatomic molecule like H2. The measured energy and angular distributions as well as the asymmetry parameter are compared with a molecular CDW-EIS (continuum distorted wave-eikonal initial state) model.

  17. Young Type Interference Effect on the Forward-Backward Asymmetry Parameter in Electron Emission from H{sub 2} Under Fast Ion Impact

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Deepankar; Kelkar, A H; Tribedi, Lokesh C [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-200 005 (India)

    2007-09-15

    We have investigated the double differential distribution of electron emission from molecular hydrogen in collisions with fast bare carbon ions in order to investigate the effect of Young type interference on the forward-backward angular asymmetry. The asymmetry parameter, derived from the cross sections for complementary forward and backward angles, shows an oscillatory behaviour as a function of electron velocity which is absent in atomic target such as He. It is shown that the asymmetry parameter which is based on the DDCS of H{sub 2} only, can be used as self normalizing way of the obtaining the Young type interference in an inversion symmetric homo-nuclear diatomic molecule like H{sub 2}. The measured energy and angular distributions as well as the asymmetry parameter are compared with a molecular CDW-EIS (continuum distorted wave-eikonal initial state) model.

  18. A novel cell-scale bio-nanogenerator based on electron-ion interaction for fast light power conversion.

    Science.gov (United States)

    Li, Yu-Tao; Tian, He; Zhao, Hai-Ming; Jian, Mu-Qiang; Lv, Yu-Jia; Tian, Ye; Wang, Qian; Yang, Yi; Xiang, Yan; Zhang, Yingying; Ren, Tian-Ling

    2018-01-03

    Natural energy haversting devices serve as an alternative candidate for power supply in many micro-/nano-systems. However, traditional nanogenerators based on piezoelectricity or triboelectric power generation face challenges in terms of biocompatibility and stability in various biological systems. The bacteriorhodopsin (bR) protein in Halobacterium halobium is an ideal biocompatible material for photoelectric conversion. Conventional bR systems based on ion transport or enhanced light absorption layers have a limited light power conversion speed. On the other hand, bR-based biohybrid devices have a great potential for sensitive light power conversion as compared to conventional nanogenerators. Herein, we present a biohybrid nanogenerator made of bR and horizontally aligned-long carbon nanotubes (CNTs) with electron-ion interaction for the first time for sensitive light power conversion. The bR layer serves as the proton pump, whereas CNTs are utilized to enhance the photocurrent; thus, the photocurrent frequency response improves significantly because of the effect of the electron-ion interaction. The photocurrent shows a linear relationship with the intensity of light and can still obtain a stable signal at a light intensity of 0.03 mW cm -2 . With regard to the influence of the light on-off period, the photocurrent initially increases and then decreases with an increase in flickering frequency up to 360 Hz; this can be ascribed to the combinational influence of light switch speed and photocycle decay time. The photocurrent shows highest value (99 nA cm -2 ) at a frequency of about 50 Hz at a light intensity of 0.43 mW cm -2 , which matches well with the frequency standard of the electrical power supply system. Moreover, we found that a higher density of CNTs contributed to improve performance of the nanogenerators. Furthermore, a H + ion releasing model was proposed to interpret the operating mechanism of the biohybrid nanogenerator. The biohybrid nanogenerator

  19. Observation of repetitive bursts in emission of fast ions and neutrons in sub-nanosecond laser-solid experiments

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Klír, D.; Velyhan, Andriy; Margarone, Daniele; Krouský, Eduard; Jungwirth, Karel; Skála, Jiří; Pfeifer, Miroslav; Kravárik, J.; Kubeš, P.; Řezáč, K.; Ullschmied, Jiří

    2013-01-01

    Roč. 31, č. 3 (2013), s. 395-401 ISSN 0263-0346 R&D Projects: GA MŠk EE2.3.20.0279; GA ČR GAP205/12/0454; GA MŠk LM2010014 Grant - others:OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279 Program:EE Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-plasma interactions * neutron yield scaling * bursts in ion emission Subject RIV: BH - Optics, Masers, Lasers; BL - Plasma and Gas Discharge Physics (UFP-V) Impact factor: 1.701, year: 2013

  20. Li2 NH-LiBH4 : a Complex Hydride with Near Ambient Hydrogen Adsorption and Fast Lithium Ion Conduction.

    Science.gov (United States)

    Wang, Han; Cao, Hujun; Zhang, Weijin; Chen, Jian; Wu, Hui; Pistidda, Claudio; Ju, Xiaohua; Zhou, Wei; Wu, Guotao; Etter, Martin; Klassen, Thomas; Dornheim, Martin; Chen, Ping

    2018-01-26

    Complex hydrides have played important roles in energy storage area. Here a complex hydride made of Li 2 NH and LiBH 4 was synthesized, which has a structure tentatively indexed using an orthorhombic cell with a space group of Pna2 1 and lattice parameters of a=10.121, b=6.997, and c=11.457 Å. The Li 2 NH-LiBH 4 sample (in a molar ratio of 1:1) shows excellent hydrogenation kinetics, starting to absorb H 2 at 310 K, which is more than 100 K lower than that of pristine Li 2 NH. Furthermore, the Li + ion conductivity of the Li 2 NH-LiBH 4 sample is about 1.0×10 -5  S cm -1 at room temperature, and is higher than that of either Li 2 NH or LiBH 4 at 373 K. Those unique properties of the Li 2 NH-LiBH 4 complex render it a promising candidate for hydrogen storage and Li ion conduction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Investigation of UHPLC/travelling-wave ion mobility/time-of-flight mass spectrometry for fast profiling of fatty acids in the high Arctic sea surface microlayer.

    Science.gov (United States)

    Rad, Farshid Mashayekhy; Leck, Caroline; Ilag, Leopold L; Nilsson, Ulrika

    2018-03-09

    Fatty acids are enriched in the ocean surface microlayer (SML) and have as a consequence been detected worldwide in sea spray aerosols. In searching for a relationship between the properties of the atmospheric aerosol and its ability to form cloud condensation nuclei and to promote cloud droplet formation over remote marine areas, the role of surface active fatty acids sourced from the SML is of interest to be investigated. Here is presented a fast method for profiling of major fatty acids in SML samples collected in the high Arctic (89 °N, 1 °W) in the summer of 2001. UHPLC/travelling-wave ion mobility spectrometry (TWIMS)/time-of-flight (TOF) mass spectrometry (MS) for profiling was evaluated and compared with UHPLC/TOFMS. No sample preparation, except evaporation and centrifugation, was necessary to perform prior to the analysis. TOFMS data on accurate mass, isotopic ratios and fragmentation patterns enabled identification of the fatty acids. The TWIMS dimension added to the selectivity by extensive reduction of the noise level and the entire UHPLC/TWIMS/TOFMS method provided a fast profiling of the acids, ranging from C 8 to C 24 . Hexadecanoic and octadecanoic acids were shown to yield the highest signals among the fatty acids detected in a high Arctic SML sample, followed by the unsaturated octadecenoic and octadecadienoic acids. The predominance of signal from even-numbered carbon chains indicates a mainly biogenic origin of the detected fatty acids. This study presents a fast alternative method for screening and profiling of fatty acids, which has the advantage of not requiring any complicated sample preparation thus limiting the loss of analytes. Almost no manual handling, together with the very small sample volumes needed, is certainly beneficial for the determination of trace amounts and should open up the field of applications to also include atmospheric aerosol and fog. This article is protected by copyright. All rights reserved.

  2. Simple, Fast and Selective Detection of Adenosine Triphosphate at Physiological pH Using Unmodified Gold Nanoparticles as Colorimetric Probes and Metal Ions as Cross-Linkers

    Directory of Open Access Journals (Sweden)

    Huan Pang

    2012-11-01

    Full Text Available We report a simple, fast and selective colorimetric assay of adenosine triphosphate (ATP using unmodified gold nanoparticles (AuNPs as probes and metal ions as cross-linkers. ATP can be assembled onto the surface of AuNPs through interaction between the electron-rich nitrogen atoms and the electron-deficient surface of AuNPs. Accordingly, Cu2+ ions induce a change in the color and UV/Vis absorbance of AuNPs by coordinating to the triphosphate groups and a ring nitrogen of ATP. A detection limit of 50 nM was achieved, which is comparable to or lower than that achievable by the currently used electrochemical, spectroscopic or chromatographic methods. The theoretical simplicity and high selectivity reported herein demonstrated that AuNPs-based colorimetric assay could be applied in a wide variety of fields by rationally designing the surface chemistry of AuNPs. In addition, our results indicate that ATP-modified AuNPs are less stable in Cu2+, Cd2+ or Zn2+-containing solutions due to the formation of the corresponding dimeric metal-ATP complexes.

  3. Impacts of lost fast ions on the TJ-II Vacuum Vessel during NBI; Impactos de los iones rapidos en la Camara de Vacio del TJ-II durante NBI

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.

    1995-07-01

    The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed. (Author) 6 refs.

  4. SU-F-T-179: Fast and Accurate Profile Acquisition for Proton Beam Using Multi-Ion Chamber Arrays

    International Nuclear Information System (INIS)

    Wang, X; Zou, J; Chen, T; Yue, N; Zhang, M; Mo, X

    2016-01-01

    Purpose: Proton beam profile measurement is more time-consuming than photon beam. Due to the energy modulation during proton delivery, chambers have to move step-by-step instead of continuously. Multi-ion chamber arrays are appealing to this task since multiple measurements can be performed at once. However, their utilization suffers from sparse spatial resolution and potential intrinsic volume-averaging effect of the disk-shaped ion chambers. We proposed an approach to measure proton beam profiles accurately and efficiently. Methods: Mevion S250 proton system and IBA Matrixx ion chamber arrays were used in this study. Matrixx has interchamber distance of 7.62 mm, and chamber diameter of 4.5 mm. We measured the same beam profile by moving the Matrixx seven times with 1 mm each time along y axis. All 7 measurements were superimposed to get a “finer” profile with 1 mm spatial resolution. Coarser resolution profiles of 2 mm and 3 mm were also generated by using subsets of measurements. Those profiles were compared to the TPS calculated beam profile. Gamma analysis was performed for 2D dose maps to evaluate the difference to TPS dose plane. Results: Preliminary results showed a large discrepancy between the TPS calculated profile and the single measurement profile with 7.6 mm resolution. A good match could be achieved when the resolution reduced to 3 mm by adding one extra measurement. Gamma analysis for 2D dose map of a 10×10 field showed a passing rate (γ ≤ 1) of 90.6% using a 3% and 3mm criterion for single measurement, which increased to 92.3% for 2-measurement superimposition, and slightly further increased to 92.9% for 7-measurement superimposition. Conclusion: The results indicated that 2 measurements shifted by 3mm using Matrixx generated a smooth proton beam profile with good matching to Eclipse beam profile. We suggest using this 2-measurement approach in clinic for double scattering proton beam profile measurement.

  5. Fred: a GPU-accelerated fast-Monte Carlo code for rapid treatment plan recalculation in ion beam therapy

    Science.gov (United States)

    Schiavi, A.; Senzacqua, M.; Pioli, S.; Mairani, A.; Magro, G.; Molinelli, S.; Ciocca, M.; Battistoni, G.; Patera, V.

    2017-09-01

    Ion beam therapy is a rapidly growing technique for tumor radiation therapy. Ions allow for a high dose deposition in the tumor region, while sparing the surrounding healthy tissue. For this reason, the highest possible accuracy in the calculation of dose and its spatial distribution is required in treatment planning. On one hand, commonly used treatment planning software solutions adopt a simplified beam-body interaction model by remapping pre-calculated dose distributions into a 3D water-equivalent representation of the patient morphology. On the other hand, Monte Carlo (MC) simulations, which explicitly take into account all the details in the interaction of particles with human tissues, are considered to be the most reliable tool to address the complexity of mixed field irradiation in a heterogeneous environment. However, full MC calculations are not routinely used in clinical practice because they typically demand substantial computational resources. Therefore MC simulations are usually only used to check treatment plans for a restricted number of difficult cases. The advent of general-purpose programming GPU cards prompted the development of trimmed-down MC-based dose engines which can significantly reduce the time needed to recalculate a treatment plan with respect to standard MC codes in CPU hardware. In this work, we report on the development of fred, a new MC simulation platform for treatment planning in ion beam therapy. The code can transport particles through a 3D voxel grid using a class II MC algorithm. Both primary and secondary particles are tracked and their energy deposition is scored along the trajectory. Effective models for particle-medium interaction have been implemented, balancing accuracy in dose deposition with computational cost. Currently, the most refined module is the transport of proton beams in water: single pencil beam dose-depth distributions obtained with fred agree with those produced by standard MC codes within 1-2% of the

  6. Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Benjamin Michael [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages of ethanol in gasoline. Consumers are increasingly demanding that energy sources be more powerful, more durable, and, ultimately, more cost efficient. Fast Ionic Conducting (FIC) glasses are a material that offers great potential for the development of new batteries and/or fuel cells to help inspire the energy density of battery power supplies. This dissertation probes the mechanisms by which ions conduct in these glasses. A variety of different experimental techniques give a better understanding of the interesting materials science taking place within these systems. This dissertation discusses Nuclear Magnetic Resonance (NMR) techniques performed on FIC glasses over the past few years. These NMR results have been complimented with other measurement techniques, primarily impedance spectroscopy, to develop models that describe the mechanisms by which ionic conduction takes place and the dependence of the ion dynamics on the local structure of the glass. The aim of these measurements was to probe the cause of a non-Arrhenius behavior of the conductivity which has been seen at high temperatures in the silver thio-borosilicate glasses. One aspect that will be addressed is if this behavior is unique to silver containing fast ion conducting glasses. more specifically, this study will determine if a non-Arrhenius correlation time, τ, can be observed in the Nuclear Spin Lattice Relaxation (NSLR) measurements. If so, then can this behavior be modeled with a new single

  7. Electron double differential cross sections for ionization of O2 under fast C6+ ion impact and interference oscillation

    Science.gov (United States)

    Nandi, Saikat; Agnihotri, A. N.; Tachino, C. A.; Rivarola, R. D.; Martín, F.; Tribedi, Lokesh C.

    2013-09-01

    The absolute double differential cross sections (DDCS) have been obtained for electron emission from oxygen molecules under the impact of bare carbon ions. The DDCS values are measured between an energy range of a few eV to 600 eV and over an angular range of 30-150°. These are then compared with the continuum distorted wave-eikonal initial state (CDW-EIS) calculations. The DDCS values for O2 are divided by that of atomic oxygen (calculated theoretically) to look for any oscillatory behaviour arising from Young-type interference. In addition, the DDCS ratios are further divided by a fitted straight line to extract any primary interference oscillation. Although a negative result has been obtained, these observations are in qualitative agreement with the prediction of the CDW-EIS model used.

  8. Electron double differential cross sections for ionization of O2 under fast C6+ ion impact and interference oscillation

    International Nuclear Information System (INIS)

    Nandi, Saikat; Agnihotri, A N; Tribedi, Lokesh C; Tachino, C A; Rivarola, R D; Martín, F

    2013-01-01

    The absolute double differential cross sections (DDCS) have been obtained for electron emission from oxygen molecules under the impact of bare carbon ions. The DDCS values are measured between an energy range of a few eV to 600 eV and over an angular range of 30–150°. These are then compared with the continuum distorted wave-eikonal initial state (CDW-EIS) calculations. The DDCS values for O 2 are divided by that of atomic oxygen (calculated theoretically) to look for any oscillatory behaviour arising from Young-type interference. In addition, the DDCS ratios are further divided by a fitted straight line to extract any primary interference oscillation. Although a negative result has been obtained, these observations are in qualitative agreement with the prediction of the CDW-EIS model used. (paper)

  9. Development and testing of a fast digital electronic system for ion identification and spectroscopy; Etude et realisation d'une chaine d'instrumentation numerique rapide pour l'identification des ions

    Energy Technology Data Exchange (ETDEWEB)

    Legou, Th

    2002-02-01

    This report deals with a fast digital electronic system developed for ion identification and spectroscopy. The system, called IRIS, has been conceived for the super heavy element research program: FUSION. In order to observe a super heavy element, the energy of the compound nucleus implanted in a silicon detector must be measured, and the alpha decay also registered. The associated electronics must therefore handle a very wide range of energies and also exhibit a small recovery time after the implantation of the compound nucleus. IRIS is connected to the output of a charge preamplifier. It digitizes the signal and then executes two digital signal processes: the first to detect the particle, and the second to determine the energy deposited in the silicon detector. The use of programmed processing allows for the adjustment of the digital processing parameters, as well as a choice of other digital signal processing procedures, depending the application. After having explained why a conventional electronic system cannot be used for the detection of super-heavy ions, IRIS' structure is detailed and a number of digital signal processing procedures are studied and tested. (author)

  10. Comparison between a radio-frequency and direct current glow discharge in argon by a hybrid Monte Carlo-fluid model for electrons, argon ions and fast argon atoms

    NARCIS (Netherlands)

    Bogaerts, A.; Gijbels, R.; W. Goedheer,

    1999-01-01

    A hybrid Monte Carlo-fluid model has been developed for the electrons, argon ions and fast argon atoms in an argon glow discharge, either operated in the de mode or the capacitively coupled rf mode. Typical working conditions for rf GD-OES are considered, i.e. approximately 6 torr argon gas pressure

  11. Environmentally-friendly aqueous Li (or Na)-ion battery with fast electrode kinetics and super-long life.

    Science.gov (United States)

    Dong, Xiaoli; Chen, Long; Liu, Jingyuan; Haller, Servane; Wang, Yonggang; Xia, Yongyao

    2016-01-01

    Current rechargeable batteries generally display limited cycle life and slow electrode kinetics and contain environmentally unfriendly components. Furthermore, their operation depends on the redox reactions of metal elements. We present an original battery system that depends on the redox of I(-)/I3 (-) couple in liquid cathode and the reversible enolization in polyimide anode, accompanied by Li(+) (or Na(+)) diffusion between cathode and anode through a Li(+)/Na(+) exchange polymer membrane. There are no metal element-based redox reactions in this battery, and Li(+) (or Na(+)) is only used for charge transfer. Moreover, the components (electrolyte/electrode) of this system are environment-friendly. Both electrodes are demonstrated to have very fast kinetics, which gives the battery a supercapacitor-like high power. It can even be cycled 50,000 times when operated within the electrochemical window of 0 to 1.6 V. Such a system might shed light on the design of high-safety and low-cost batteries for grid-scale energy storage.

  12. Energy and angular distribution of electrons ejected from water by the impact of fast O8+ ion beams

    Science.gov (United States)

    Bhattacharjee, Shamik; Bagdia, Chandan; Chowdhury, Madhusree Roy; Monti, Juan M.; Rivarola, Roberto D.; Tribedi, Lokesh C.

    2018-01-01

    Double differential cross sections (DDCS) of electrons emitted from vapor water molecules (in vapor phase) by 2.0 MeV/u and 3.75 MeV/u bare oxygen ion impact have been measured by continuum electron spectroscopy technique. The ejected electrons were detected by an electrostatic hemispherical deflection analyzer over an energy range of 1-600 eV and emission angles from 20∘ to 160∘. The DDCS data has been compared with the continuum-distorted-wave-eikonal-initial state (CDW-EIS) approximation and a reasonable agreement was found with both version of the models i.e. post and prior version. By numerical integration of the DDCS data, the single differential cross section (SDCS) and total ionization cross section (TCS) were obtained. The obtained TCS results were compared with other available TCS results for water target within the same energy range. The total ionization cross sections values are seen to saturate as the projectile charge state ( q p ) increases, which is in contrast to the first-Born predicted q p 2 dependence. This is also in contrast to the prediction of the CDW-EIS models.

  13. Electron emission in ionization of He and Ne by fast dressed oxygen ions and projectile-charge-state dependence

    Science.gov (United States)

    Biswas, Shubhadeep; Kasthurirangan, S.; Misra, D.; Monti, J. M.; Rivarola, R. D.; Fainstein, P. D.; Tribedi, L. C.

    2015-02-01

    The double-differential cross sections (DDCS) of low-energy electrons emitted at forward, backward, and perpendicular directions are reported for collisions of 3.75 MeV/u Oq + (q =5 , 6, 7, 8) projectiles with He and Ne targets. The measured DDCS are found to be deviating from the q2 dependence throughout the entire energy region. The effect of projectile electrons, for the dressed ions, as a function of the impact parameter is clearly noticeable for large as well as low-impact parameter collisions. We also present a theoretical calculation based on the prior form of the continuum distorted wave-eikonal initial state approximation, in which the projectile-active electron interaction is modeled with the Green-Sellin-Zachor potential. This particular representation of the potential has been proven to give good qualitative results for projectiles with residual electrons. In addition to the total DDCS, the individual contributions from target ionization, projectile electron loss, and simultaneous ionization processes are also calculated. The total DDCS obtained from these calculations are shown to be in excellent agreement with the experimental observations.

  14. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    Science.gov (United States)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Tribedi, L. C.

    2007-09-01

    Se have investigated single and double ionization of C60 molecule in collisions with 2.33 MeV/u Siq+ (q=6-14) and 3.125 MeV/u Oq+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  15. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C

    2007-01-01

    Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening

  16. Differential electron emission in the ionization of Ne and Xe atoms under fast bare carbon ion impact

    Science.gov (United States)

    Biswas, Shubhadeep; Monti, J. M.; Tachino, C. A.; Rivarola, R. D.; Tribedi, L. C.

    2015-06-01

    Measurement of the energy and angular distributions of the double differential cross section (DDCS) of electron emission from Ne and Xe atoms in collision with 5 MeV u-1 bare carbon ions is reported. This study aimed to investigate the electron emission processes in the case of multi-electronic systems. In general, several clear differences between the electron emission spectra of Ne and Xe are found, which indicate the influence of the increasing number of electrons. For instance, the sharp peak due to the binary nature of collision is almost absent in the case of Xe, unlike Ne, which could be understood due to the increasing contribution from the strongly bound inner shell (such as 4d) electrons for the Xe atom. The forward-backward angular asymmetry has also been derived from the angular distributions. For Xe, the qualitative behaviour of the asymmetry parameter is seen to be quite different since it reveals structures due to Auger contributions. It is, in general, different and much lower than that for Ne, which shows the smooth behaviour that one finds for other lighter atoms like He. The single differential and total cross sections are also derived. The theoretical calculations based on the prior form of the continuum distorted wave-eikonal initial state (CDW-EIS) approximation have been provided for both the targets. Overall, it gives a very good agreement with the energy and the angular distributions of DDCS for Ne. For Xe, the agreement is not as good as for Ne. We also provide a detailed discussion on the DDCS obtained from different sub-shell ionization, estimated in this framework.

  17. Double differential electron emission from N2 under impact of fast C6+ ions and Young-type interference

    Science.gov (United States)

    Nandi, Saikat; Biswas, Shubhadeep; Tachino, Carmen A.; Rivarola, Roberto D.; Tribedi, Lokesh C.

    2015-08-01

    The absolute Double Differential Cross Sections (DDCS) have been obtained for electron emission from nitrogen molecule under the impact of 72 MeV bare carbon ions. The energy dependence of the electron DDCS was studied for 12 different angles: 20°, 30°, 45°, 60°, 75°, 80°, 90°, 105°, 120°, 135°, 150°, and 160°. At each angle the emitted electrons having energies between 1 and 500 eV were detected. The main interest is to look for the possible existence of interference patterns in the electron spectra due to coherent emission from the two molecular centers. The dynamics of the interaction is described within the continuum distorted wave-eikonal initial state model (CDW-EIS). The DDCS ratios (i.e N2/2N) do not show a clear signature of the oscillatory behavior arising from the interference unlike that observed in the case of H2. The forward-backward angular asymmetry( α) parameter, as deduced from DDCS values at 30° and 150°, increases monotonically with velocity of the emitted electrons and does show a mild oscillation due to the Young-type electron interference in a molecular double slit. These observations are in qualitative agreement with the prediction of the CDW-EIS model. The apparent absence of the oscillation in the DDCS ratios or a mild oscillation in the α-parameter is qualitatively explained in terms of partial cancellation of contributions arising from different molecular orbitals. The single differential cross sections (SDCS) are well reproduced by the CDW-EIS model as well as the semi-empirical Rudd model. The overall agreement of the DDCS data with the CDW-EIS is extremely good. However, a closer inspection revealed occasional deviations in the angular distribution, particularly in extreme forward and backward angles.

  18. Initial development of goCMC: a GPU-oriented fast cross-platform Monte Carlo engine for carbon ion therapy.

    Science.gov (United States)

    Qin, Nan; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B; Parodi, Katia; Jia, Xun

    2017-05-07

    Monte Carlo (MC) simulation is considered as the most accurate method for calculation of absorbed dose and fundamental physics quantities related to biological effects in carbon ion therapy. To improve its computational efficiency, we have developed a GPU-oriented fast MC package named goCMC, for carbon therapy. goCMC simulates particle transport in voxelized geometry with kinetic energy up to 450 MeV u -1 . Class II condensed history simulation scheme with a continuous slowing down approximation was employed. Energy straggling and multiple scattering were modeled. δ-electrons were terminated with their energy locally deposited. Four types of nuclear interactions were implemented in goCMC, i.e. carbon-hydrogen, carbon-carbon, carbon-oxygen and carbon-calcium inelastic collisions. Total cross section data from Geant4 were used. Secondary particles produced in these interactions were sampled according to particle yield with energy and directional distribution data derived from Geant4 simulation results. Secondary charged particles were transported following the condensed history scheme, whereas secondary neutral particles were ignored. goCMC was developed under OpenCL framework and is executable on different platforms, e.g. GPU and multi-core CPU. We have validated goCMC with Geant4 in cases with different beam energy and phantoms including four homogeneous phantoms, one heterogeneous half-slab phantom, and one patient case. For each case [Formula: see text] carbon ions were simulated, such that in the region with dose greater than 10% of maximum dose, the mean relative statistical uncertainty was less than 1%. Good agreements for dose distributions and range estimations between goCMC and Geant4 were observed. 3D gamma passing rates with 1%/1 mm criterion were over 90% within 10% isodose line except in two extreme cases, and those with 2%/1 mm criterion were all over 96%. Efficiency and code portability were tested with different GPUs and CPUs. Depending on the

  19. Initial development of goCMC: a GPU-oriented fast cross-platform Monte Carlo engine for carbon ion therapy

    Science.gov (United States)

    Qin, Nan; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B.; Parodi, Katia; Jia, Xun

    2017-05-01

    Monte Carlo (MC) simulation is considered as the most accurate method for calculation of absorbed dose and fundamental physics quantities related to biological effects in carbon ion therapy. To improve its computational efficiency, we have developed a GPU-oriented fast MC package named goCMC, for carbon therapy. goCMC simulates particle transport in voxelized geometry with kinetic energy up to 450 MeV u-1. Class II condensed history simulation scheme with a continuous slowing down approximation was employed. Energy straggling and multiple scattering were modeled. δ-electrons were terminated with their energy locally deposited. Four types of nuclear interactions were implemented in goCMC, i.e. carbon-hydrogen, carbon-carbon, carbon-oxygen and carbon-calcium inelastic collisions. Total cross section data from Geant4 were used. Secondary particles produced in these interactions were sampled according to particle yield with energy and directional distribution data derived from Geant4 simulation results. Secondary charged particles were transported following the condensed history scheme, whereas secondary neutral particles were ignored. goCMC was developed under OpenCL framework and is executable on different platforms, e.g. GPU and multi-core CPU. We have validated goCMC with Geant4 in cases with different beam energy and phantoms including four homogeneous phantoms, one heterogeneous half-slab phantom, and one patient case. For each case 3× {{10}7} carbon ions were simulated, such that in the region with dose greater than 10% of maximum dose, the mean relative statistical uncertainty was less than 1%. Good agreements for dose distributions and range estimations between goCMC and Geant4 were observed. 3D gamma passing rates with 1%/1 mm criterion were over 90% within 10% isodose line except in two extreme cases, and those with 2%/1 mm criterion were all over 96%. Efficiency and code portability were tested with different GPUs and CPUs. Depending on the beam

  20. Integrated fast assembly of free-standing lithium titanate/carbon nanotube/cellulose nanofiber hybrid network film as flexible paper-electrode for lithium-ion batteries.

    Science.gov (United States)

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Xue, Xin; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2015-05-27

    A free-standing lithium titanate (Li4Ti5O12)/carbon nanotube/cellulose nanofiber hybrid network film is successfully assembled by using a pressure-controlled aqueous extrusion process, which is highly efficient and easily to scale up from the perspective of disposable and recyclable device production. This hybrid network film used as a lithium-ion battery (LIB) electrode has a dual-layer structure consisting of Li4Ti5O12/carbon nanotube/cellulose nanofiber composites (hereinafter referred to as LTO/CNT/CNF), and carbon nanotube/cellulose nanofiber composites (hereinafter referred to as CNT/CNF). In the heterogeneous fibrous network of the hybrid film, CNF serves simultaneously as building skeleton and a biosourced binder, which substitutes traditional toxic solvents and synthetic polymer binders. Of importance here is that the CNT/CNF layer is used as a lightweight current collector to replace traditional heavy metal foils, which therefore reduces the total mass of the electrode while keeping the same areal loading of active materials. The free-standing network film with high flexibility is easy to handle, and has extremely good conductivity, up to 15.0 S cm(-1). The flexible paper-electrode for LIBs shows very good high rate cycling performance, and the specific charge/discharge capacity values are up to 142 mAh g(-1) even at a current rate of 10 C. On the basis of the mild condition and fast assembly process, a CNF template fulfills multiple functions in the fabrication of paper-electrode for LIBs, which would offer an ever increasing potential for high energy density, low cost, and environmentally friendly flexible electronics.

  1. Modelling of radio frequency sheath and fast wave coupling on the realistic ion cyclotron resonant antenna surroundings and the outer wall

    Science.gov (United States)

    Lu, L.; Colas, L.; Jacquot, J.; Després, B.; Heuraux, S.; Faudot, E.; Van Eester, D.; Crombé, K.; Křivská, A.; Noterdaeme, J.-M.; Helou, W.; Hillairet, J.

    2018-03-01

    In order to model the sheath rectification in a realistic geometry over the size of ion cyclotron resonant heating (ICRH) antennas, the self-consistent sheaths and waves for ICH (SSWICH) code couples self-consistently the RF wave propagation and the DC SOL biasing via nonlinear RF and DC sheath boundary conditions applied at plasma/wall interfaces. A first version of SSWICH had 2D (toroidal and radial) geometry, rectangular walls either normal or parallel to the confinement magnetic field B 0 and only included the evanescent slow wave (SW) excited parasitically by the ICRH antenna. The main wave for plasma heating, the fast wave (FW) plays no role on the sheath excitation in this version. A new version of the code, 2D SSWICH-full wave, was developed based on the COMSOL software, to accommodate full RF field polarization and shaped walls tilted with respect to B 0 . SSWICH-full wave simulations have shown the mode conversion of FW into SW occurring at the sharp corners where the boundary shape varies rapidly. It has also evidenced ‘far-field’ sheath oscillations appearing at the shaped walls with a relatively long magnetic connection length to the antenna, that are only accessible to the propagating FW. Joint simulation, conducted by SSWICH-full wave within a multi-2D approach excited using the 3D wave coupling code (RAPLICASOL), has recovered the double-hump poloidal structure measured in the experimental temperature and potential maps when only the SW is modelled. The FW contribution on the potential poloidal structure seems to be affected by the 3D effects, which was ignored in the current stage. Finally, SSWICH-full wave simulation revealed the left–right asymmetry that has been observed extensively in the unbalanced strap feeding experiments, suggesting that the spatial proximity effects in RF sheath excitation, studied for SW only previously, is still important in the vicinity of the wave launcher under full wave polarizations.

  2. Probing the Complexities of Structural Changes in Layered Oxide Cathode Materials for Li-Ion Batteries during Fast Charge-Discharge Cycling and Heating.

    Science.gov (United States)

    Hu, Enyuan; Wang, Xuelong; Yu, Xiqian; Yang, Xiao-Qing

    2018-02-20

    The rechargeable lithium-ion battery (LIB) is the most promising energy storage system to power electric vehicles with high energy density and long cycling life. However, in order to meet customers' demands for fast charging, the power performances of current LIBs need to be improved. From the cathode aspect, layer-structured cathode materials are widely used in today's market and will continue to play important roles in the near future. The high rate capability of layered cathode materials during charging and discharging is critical to the power performance of the whole cell and the thermal stability is closely related to the safety issues. Therefore, the in-depth understanding of structural changes of layered cathode materials during high rate charging/discharging and the thermal stability during heating are essential in developing new materials and improving current materials. Since structural changes take place from the atomic level to the whole electrode level, combination of characterization techniques covering multilength scales is quite important. In many cases, this means using comprehensive tools involving diffraction, spectroscopy, and imaging to differentiate the surface from the bulk and to obtain structural/chemical information with different levels of spatial resolution. For example, hard X-ray spectroscopy can yield the bulk information and soft X-ray spectroscopy can give the surface information; X-ray based imaging techniques can obtain spatial resolution of tens of nanometers, and electron-based microcopy can go to angstroms. In addition to challenges associated with different spatial resolution, the dynamic nature of structural changes during high rate cycling and heating requires characterization tools to have the capability of collecting high quality data in a time-resolved fashion. Thanks to the advancement in synchrotron based techniques and high-resolution electron microscopy, high temporal and spatial resolutions can now be achieved. In

  3. Poly(1-vinylimidazole) functionalized magnetic ion imprinted polymer for fast and selective extraction of trace gold in geological, environmental and biological samples followed by graphite furnace atomic absorption spectrometry detection

    Science.gov (United States)

    Zhao, Bingshan; He, Man; Chen, Beibei; Xu, Hongrun; Hu, Bin

    2018-05-01

    In this study, poly(1-vinylimidazole) functionalized gold ion imprinted polymer coated magnetic nanoparticles (MNPs@PVIM-Au-IIP) were prepared and characterized. The adsorption behaviors of the prepared MNPs@PVIM-Au-IIP toward gold ions (Au(III)) were studied, it was found that MNPs@PVIM-Au-IIP has good selectivity, high adsorption capacity (185.4 mg g-1) and fast adsorption kinetic for Au(III). Based on it, a new method of ion imprinted magnetic solid phase extraction (II-MSPE) coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the analysis of trace Au(III) in real samples with complicated matrix. Factors affecting MSPE including sample pH, desorption reagent, elution concentration and volume, elution time, sample volume and adsorption time were optimized. With high enrichment factor of 100-fold, the detection limit of the proposed method is 7.9 ng L-1 for Au(III) with the relative standard deviation of 7.4% (c = 50 ng L-1, n = 7). In order to validate the accuracy of the proposed method, the Certified Reference Material of GBW07293 geological sample (platinpalladium ore) was analyzed, and the determined value was in good agreement with the certified value. The proposed II-MSPE-GFAAS method is simple, fast, selective, sensitive and has been successfully applied in the determination of trace Au in ore, sediment, environmental water and human urine samples with satisfactory results.

  4. Classification of jet fuels by fuzzy rule-building expert systems applied to three-way data by fast gas chromatography--fast scanning quadrupole ion trap mass spectrometry.

    Science.gov (United States)

    Sun, Xiaobo; Zimmermann, Carolyn M; Jackson, Glen P; Bunker, Christopher E; Harrington, Peter B

    2011-01-30

    A fast method that can be used to classify unknown jet fuel types or detect possible property changes in jet fuel physical properties is of paramount interest to national defense and the airline industries. While fast gas chromatography (GC) has been used with conventional mass spectrometry (MS) to study jet fuels, fast GC was combined with fast scanning MS and used to classify jet fuels into lot numbers or origin for the first time by using fuzzy rule-building expert system (FuRES) classifiers. In the process of building classifiers, the data were pretreated with and without wavelet transformation and evaluated with respect to performance. Principal component transformation was used to compress the two-way data images prior to classification. Jet fuel samples were successfully classified with 99.8 ± 0.5% accuracy for both with and without wavelet compression. Ten bootstrapped Latin partitions were used to validate the generalized prediction accuracy. Optimized partial least squares (o-PLS) regression results were used as positively biased references for comparing the FuRES prediction results. The prediction results for the jet fuel samples obtained with these two methods were compared statistically. The projected difference resolution (PDR) method was also used to evaluate the fast GC and fast MS data. Two batches of aliquots of ten new samples were prepared and run independently 4 days apart to evaluate the robustness of the method. The only change in classification parameters was the use of polynomial retention time alignment to correct for drift that occurred during the 4-day span of the two collections. FuRES achieved perfect classifications for four models of uncompressed three-way data. This fast GC/fast MS method furnishes characteristics of high speed, accuracy, and robustness. This mode of measurement may be useful as a monitoring tool to track changes in the chemical composition of fuels that may also lead to property changes. Copyright © 2010

  5. A highly selective and fast-response fluorescent probe based on Cd-MOF for the visual detection of Al3+ ion and quantitative detection of Fe3+ ion

    Science.gov (United States)

    Lv, Rui; Chen, Zhihengyu; Fu, Xin; Yang, Boyi; Li, Hui; Su, Jian; Gu, Wen; Liu, Xin

    2018-03-01

    A new luminescent Cd(II)-based metal-organic framework, [Cd(PAM)(4-bpdb)1.5]·DMF (Cd-MOF, PAM = 4,4‧-methylenebis(3-hydroxy-2-naphthalene-carboxylic acid) and 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene) was successfully synthesized by solvothermal synthesis method. The Cd-MOF reveals excellent luminescence property which can selectively detect Al3+ and Fe3+ ions among other interfering metal ions. The detection limit is 0.56 μM for Al3+ ion in aqueous solutions, and it is obvious lower than the maximum standard of Al3+ ion in drinking water of 7.41 μM which is defined by the WHO. More importantly, the Cd-MOF shows an obvious luminescent color change from yellow to blue under the UV lamp irradiation at 365 nm with the dropping of Al3+ ion, which can make it apply to the visual detection. And, the detection based on the test paper was explored for the first time. In addition, the Cd-MOF can also be used for quantitative detecting Fe3+ ion, and the LOD for Fe3+ ion can be as low as 0.3 μM which is lower than most reported MOFs. It is worth noting that Fe3+ and Al3+ ions can not interfere with each other. These properties make it become an excellent luminescence sensor for the detection of Al3+ and Fe3+ ions.

  6. Some remarks on in-situ studies using TEM-heavy-ion accelerator link from the stand point of extracting radiation damage caused by fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ishino, Shiori, E-mail: ishino@k9.dion.ne.jp [University of Tokyo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Sekimura, Naoto [Department of Nuclear Engineering and Management, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Murakami, Kenta [Nuclear Professional School, University of Tokyo, Tokai-mura, Naka-gun, Ibaraki, 319-1194 (Japan); Abe, Hiroaki [Institute of Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577 (Japan)

    2016-04-01

    Radiation damage of materials for fission and fusion reactors has been scaled in terms of the number of displacements per atoms (dpa). The method of evaluating the dpa has been established and standardized. However, it has become obvious that more detailed analyses are required, particularly for the nature and spatial distribution of the introduced point defects and their clusters. Such detailed nature of the defects introduced is thought to be governed by the primary knock-on atom (PKA) spectrum, A number of trials to elucidate the PKA dependent radiation effects by choosing the mass and energy of the incident ions have been explored. In some cases, defect formation by a single impinging ion has been observed. However, it has also been recognized that there are a number of artefacts arising from energy deposition distributions, existence of surface sinks together with radiation induced surface modifications and so on. In this paper, discussion will be made on how to establish irradiation correlation between neutron and heavy ion irradiations in a cascade damage formation regime. For the past fifty years, the correlation between neutron and ion irradiations from the view point of simulating the neutron radiation damage by ion irradiations has been discussed many times. However, the correlation itself has not been fully discussed separately. This is the major objective of this paper.

  7. Low energy electron spectroscopy of C{sub 60} in collisions with fast bare ions: Observation of GDPR peak and its angular distribution

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Misra, D; Chatterjee, S; Kasthurirangan, S; Agnihotri, A; Tribedi, L C, E-mail: lokesh@tifr.res.i [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005 (India)

    2009-11-01

    We report the first direct measurement of GDPR peak in heavy ion (4 MeV/u F''9''+) induced secondary electron DDCS (double differential cross section) spectrum of C{sub 60} fullerene. A peak corresponding to GDPR is seen at all angles and the angular distribution, showing a dip at 90''0, is in contrast with ion-atom collisions, indicating plasmon oscillations along beam direction. A comparison has also been done between C{sub 60} and other gaseous targets as well as with state-of-the art theoretical models, based on density functional methods.

  8. Low energy electron spectroscopy of C60 in collisions with fast bare ions: Observation of GDPR peak and its angular distribution

    Science.gov (United States)

    Kelkar, A. H.; Misra, D.; Chatterjee, S.; Kasthurirangan, S.; Agnihotri, A.; Tribedi, L. C.

    2009-11-01

    We report the first direct measurement of GDPR peak in heavy ion (4 MeV/u F9+) induced secondary electron DDCS (double differential cross section) spectrum of C60 fullerene. A peak corresponding to GDPR is seen at all angles and the angular distribution, showing a dip at 90°, is in contrast with ion-atom collisions, indicating plasmon oscillations along beam direction. A comparison has also been done between C60 and other gaseous targets as well as with state-of-the art theoretical models, based on density functional methods.

  9. Low energy electron spectroscopy of C60 in collisions with fast bare ions: Observation of GDPR peak and its angular distribution

    International Nuclear Information System (INIS)

    Kelkar, A H; Misra, D; Chatterjee, S; Kasthurirangan, S; Agnihotri, A; Tribedi, L C

    2009-01-01

    We report the first direct measurement of GDPR peak in heavy ion (4 MeV/u F''9''+) induced secondary electron DDCS (double differential cross section) spectrum of C 60 fullerene. A peak corresponding to GDPR is seen at all angles and the angular distribution, showing a dip at 90''0, is in contrast with ion-atom collisions, indicating plasmon oscillations along beam direction. A comparison has also been done between C 60 and other gaseous targets as well as with state-of-the art theoretical models, based on density functional methods.

  10. A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Proposed Medium Energy Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nissen, Edward W.; Hutton, Andrew M.; Kimber, Andrew J.

    2013-06-01

    The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations.

  11. Optimal Conditions for Fast Charging and Long Cycling Stability of Silicon Microwire Anodes for Lithium Ion Batteries, and Comparison with the Performance of Other Si Anode Concepts

    OpenAIRE

    Enrique Quiroga-González; Jürgen Carstensen; Helmut Föll

    2013-01-01

    Cycling tests under various conditions have been performed for lithium ion battery anodes made from free-standing silicon microwires embedded at one end in a copper current collector. Optimum charging/discharging conditions have been found for which the anode shows negligible fading (< 0.001%) over 80 cycles; an outstanding result for this kind of anodes. Several performance parameters of the anode have been compared to the ones of other Si anode concepts, showing that especially the capacity...

  12. A Simple and Fast Method Based on New Magnetic Ion Imprinted Polymer as a Highly Selective Sorbent for Preconcentration and Determination of Cadmium in Environmental Samples.

    Science.gov (United States)

    Panjali, Zahra; Asgharinezhad, Ali Akbar; Ebrahimzadeh, Homeira; Jalilian, Niloofar; Yarahmadi, Rasoul; Shahtaheri, Seyed Jamaleddin

    2016-08-01

    The analysis of heavy metals at trace level is one of the main toxicologists concern, due to their vital rules in human`s life. Cadmium is one of these toxic heavy metals, which released to the environment from various industries. In order to determine Cd (II) ions in various matrices magnetic ion-imprinted polymer (IIP) method has been developed and applied. This nano-sorbent has been synthesized by coating an IIP compound on Fe 3 O 4 nanoparticles core to achieve highest surface area. This polymer has been used to evaluate Cd (II) levels in food, river, and wastewater in Tehran, Iran. Fe 3 O 4 @Cd-IIP was stable up to 300 °C. The various factors such as sample pH (optimized as 7), elution/sorption time (5 min), eluent amount (4 mL HCL), and its concentration (2 mol L -1 ) were optimized. Analysis instrument in all steps was Flame Atomic Abortion Spectrophotometer (FAAS). In this study, the detection limit was determined down to 0.6 μg L -1 . This method was applied successfully for the preconcentration and determination of Cd (II) ions in environmental samples obtained from rivers, various foods and wastewater. In addition, the accuracy of the method was confirmed by analyzing a certified reference material (Seronorm LOT NO2525) and spiked real samples.

  13. Solid-State Li-Ion Batteries Using Fast, Stable, Glassy Nanocomposite Electrolytes for Good Safety and Long Cycle-Life.

    Science.gov (United States)

    Tan, Guoqiang; Wu, Feng; Zhan, Chun; Wang, Jing; Mu, Daobin; Lu, Jun; Amine, Khalil

    2016-03-09

    The development of safe, stable, and long-life Li-ion batteries is being intensively pursued to enable the electrification of transportation and intelligent grid applications. Here, we report a new solid-state Li-ion battery technology, using a solid nanocomposite electrolyte composed of porous silica matrices with in situ immobilizing Li(+)-conducting ionic liquid, anode material of MCMB, and cathode material of LiCoO2, LiNi1/3Co1/3Mn1/3O2, or LiFePO4. An injection printing method is used for the electrode/electrolyte preparation. Solid nanocomposite electrolytes exhibit superior performance to the conventional organic electrolytes with regard to safety and cycle-life. They also have a transparent glassy structure with high ionic conductivity and good mechanical strength. Solid-state full cells tested with the various cathodes exhibited high specific capacities, long cycling stability, and excellent high temperature performance. This solid-state battery technology will provide new avenues for the rational engineering of advanced Li-ion batteries and other electrochemical devices.

  14. Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions; Contribution a l'etude de la pulverisation et de l'endommagement du dioxyde d'uranium par les ions lourds rapides

    Energy Technology Data Exchange (ETDEWEB)

    Schlutig, S

    2001-03-01

    Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our results. Finally, the sputtering yields are compared with a set of earlier experimental data on uranium dioxide damage obtained by T. Wiss and we observe that only a small fraction of UO{sub 2} monolayers are sputtered. (author)

  15. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C

    2007-01-01

    We have investigated the single and multiple ionizations of the C 60 molecule in collisions with fast Si q+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process

  16. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions

    Science.gov (United States)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Kumar, A.; Tribedi, L. C.

    2007-06-01

    We have investigated the single and multiple ionizations of the C60 molecule in collisions with fast Siq+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  17. Effect of multiple plasmon excitation on single, double and multiple ionizations of C{sub 60} in collisions with fast highly charged Si ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

    2007-06-28

    We have investigated the single and multiple ionizations of the C{sub 60} molecule in collisions with fast Si{sup q+} projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  18. Behaviour of direct and delayed fast ion losses during NBI on TJ-II; Comportamiento de las perdidas instantaneas y retardadas en la inyeccion de neutros del TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Liniers, M.

    1995-07-01

    The dependence with density and beam energy of the different kind of fast ion losses, direct and delayed, during tangential balanced NBI injection in TJ-II helical axis stellarator has been analysed. Direct losses increase with energy and a strong difference between the two injection directions appears, are produced by passing particles that loss confinement in a few {mu}sec and the influence of birth profiles produces an increase with density. Delayed losses are very well separated in time from direct ones, are produced by particles experimenting pitch angle scattering and, most o them, correspond to trapped particles. Are much less important than the direct ones (about 1/3), decrease slowly with energy and, with C X, increase with density (an effect of initial profile). The absorption is rather independent of energy with low values at low density in reason of high shine through and C X losses, but recovers quickly with the density increase. (Author) 4 refs.

  19. L X-ray emission from fast highly charged Cu ions in collisions with gaseous targets: Saturation effect in excitation and transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ajay [Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India); Misra, D. [Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India); Kadhane, U. [Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India); Kelkar, A.H. [Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India); Dhal, B.B. [School of Physics, University of Melbourne, Victoria 3010 (Australia); Tribedi, L.C. [Tata Institute of Fundamental Research, Colaba, Mumbai-400 005 (India)]. E-mail: lokesh@tifr.res.in

    2006-11-15

    We have measured L X-ray production cross sections for highly charged 156 MeV Be-like Cu ions in collisions with gaseous targets of H{sub 2}, Ne, Ar, Kr and Xe. In the present collision systems, measured projectile L X-ray intensity is contributed by the excitation as well as electron transfer processes. The projectile L X-ray production cross sections are found to increase initially and then saturate with increasing target atomic number. The charge state dependence of projectile L X-ray production cross sections have been measured with Kr target.

  20. Study of Ni-dopped MnCo2O4 Yolk-Shell Submicron-spheres with Fast Li+ Intercalation Pseudocapacitance As An Anode for High-Performance Lithium Ion Batteries

    International Nuclear Information System (INIS)

    Wu, Lijun; Lang, Junwei; Wang, Shuai; Zhang, Peng; Yan, Xingbin

    2016-01-01

    Spinel Ni-dopped MnCo 2 O 4 powder with fast Li + intercalation pseudocapacitance is prepared from transition metal carbonates of Ni, Co and Mn as precursors through a solvothermal synthesis followed by an annealing treatment. As-made products are nanovoids submicron-spheres (the diameter is 500 nm–700 nm) with an obvious yolk-shell structure and uniform elements distribution. As an anode material with fast Li + intercalation pseudocapacitance for lithium-ion battery (LIB), the Ni-dopped MnCo 2 O 4 submicron-spheres exhibit an impressively first discharge efficiency (70%) and outstanding large-current cycling performance. The excellent electrochemical performance is closely ascribed to Li + intercalation pseudocapacitance and the yolk-shell structure, which can effectively prevent the particles from being pulverized, and alleviate the volume changes of particles during the cycling process. In addition, the doping of Ni metal element to MnCo 2 O 4 greatly enhances the electrochemical stability of MnCo 2 O 4 , due to the complementarities and synergies between the three metallic elements during the process of Li insertion or extraction reactions.

  1. A generic approach for expanding homolog-targeted residue screening of sulfonamides using a fast matrix separation and class-specific fragmentation-dependent acquisition with a hybrid quadrupole-linear ion trap mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Huang Chunlin [Department of Biochemistry and Molecular Biology, School of Pharmacy and Life Science, University of South China, Hengyang 421001 (China); Guo Bin, E-mail: binnguo@126.com [Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081 (China); Wang Xiaoying [Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081 (China); Li Jie [Department of Biochemistry and Molecular Biology, School of Pharmacy and Life Science, University of South China, Hengyang 421001 (China); Zhu Weitao; Chen Bo [Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081 (China); Ouyang Shan [Food Inspection and Quarantine Center, Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People' s Republic of China, Shenzhen 518067 (China); Yao Shouzhuo [Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081 (China)

    2012-08-06

    Highlights: Black-Right-Pointing-Pointer Generic homolog-targeted screening approach for multi-residual sulfonamide analogs. Black-Right-Pointing-Pointer Single-tube extraction/partitioning-multifunction adsorption cleanup for direct injection. Black-Right-Pointing-Pointer Class-specific fragmentation for expanding coverage of N{sup 4}-acetyl and N-OH metabolites. Black-Right-Pointing-Pointer PreS-IDA-EPI in LC-QqLIT for simultaneous screening and confirmation of real samples. - Abstract: A generic and efficient homolog-targeted approach was used to expand screening and detection of target class of sulfonamides and structural analogs, based on a fast single-tube extraction/partitioning-multifunction adsorption cleanup (SEP/MAC) for class-specific fragmentation-dependent acquisition with a liquid chromatography-hybrid triple-quadrupole linear ion trap mass spectrometer (LC-QqLIT). By combining the two-stage process conducted in a single tube as one-pot protocol, the straightforward SEP/MAC procedure was optimized to offer clean extracts with reasonable recovery (71-109% with RSDs < 20%) and decreased matrix interferences (-9 to 19%) of multiresidual sulfonamide extraction from different tissue samples. The novel use of neutral loss scan of 66 Da (NLS) or precursor ion scanning of m/z 108 (PreS) in positive ion mode was found to achieve more comprehensive coverage of protonated molecular ions of a wide array of sulfonamides including N{sup 4}-acetyl and hydroxylamine metabolites plus their possible dimers. Moreover, the PreS-triggered automatically enhanced product ion spectral acquisition enabled simultaneous screening, profiling and confirmation of an unlimited number of analytes belonging to the sulfonamide class within a single analysis. The validation and application results of the generic SEP/MAC-based LC-QqLIT strategy consistently demonstrated favorable performances with acceptable accuracy (67-116%), precision (RSDs < 25%), and sensitivity (LOQs {<=} 7.5 ng

  2. BaSnF4 fast ion conductor: Variations versus the method of preparation and anomalous temperature variation of the quadrupole splitting

    International Nuclear Information System (INIS)

    Hantash, Jamil; Bartlett, Alan; Denes, Georges; Muntasar, Abdualhafeed; Oldfield, Philip

    2005-01-01

    A new method of preparation of high performance fluoride ion conductor, BaSnF 4 , by water leaching of newly discovered barium tin(II) chloride fluorides, has been designed, and the materials have been studied and compared to the solid prepared by the usual dry method. The unit-cell parameters and crystallite dimensions were found to vary with the method of preparation. In addition, the crystallite dimensions were found to be highly anisotropic for the samples obtained by the wet method. The Moessbauer spectrum is made of a large tin(II) quadrupole doublet, and a broad tin(IV) oxide peak due to surface oxidation. The tin(II) spectrum is in agreement with covalently bonded tin(II) having a strongly stereoactive lone pair. An unusually high dependence of the quadrupole splitting at low temperatures was observed (5.8 times larger than for α-SnF 2 ).

  3. Two center Electron Emission in fast Collisions of Bare C and F Ions with He and H{sub 2} and CDW-EIS Mode

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Deepankar [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005 (India); Kelkar, A H [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005 (India); Fainstein, P D [Centra Atomico Bariloche, 8400 Bariloche (Argentina); Tribedi, Lokesh C [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005 (India)

    2007-09-15

    We report the energy and angular distributions of the electron double differential cross sections (DDCS) for two collision systems: 6 MeV/u C{sup 6+} on H{sub 2} and 4 MeV/u F{sup 9+} ions on He. The electrons having energies between 1 and 500 eV are detected at about ten different emission angles between 30{sup 0} and 150{sup 0}. The measured data is compared with the state-of-the art continuum distorted wave-eikonal initial state (CDW-EIS) and the first Born (B1) models. In case of molecular H{sub 2} target a molecular wave function as been used for the calculations of the cross section of H{sub 2}. A comparative study has been presented for the spectral shape for the atomic (He) and molecular (H{sub 2}) target.

  4. Two center Electron Emission in fast Collisions of Bare C and F Ions with He and H2 and CDW-EIS Mode

    Science.gov (United States)

    Misra, Deepankar; Kelkar, A. H.; Fainstein, P. D.; Tribedi, Lokesh C.

    2007-09-01

    We report the energy and angular distributions of the electron double differential cross sections (DDCS) for two collision systems: 6 MeV/u C6+ on H2 and 4 MeV/u F9+ ions on He. The electrons having energies between 1 and 500 eV are detected at about ten different emission angles between 30° and 150°. The measured data is compared with the state-of-the art continuum distorted wave-eikonal initial state (CDW-EIS) and the first Born (B1) models. In case of molecular H2 target a molecular wave function as been used for the calculations of the cross section of H2. A comparative study has been presented for the spectral shape for the atomic (He) and molecular (H2) target.

  5. Optimal Conditions for Fast Charging and Long Cycling Stability of Silicon Microwire Anodes for Lithium Ion Batteries, and Comparison with the Performance of Other Si Anode Concepts

    Directory of Open Access Journals (Sweden)

    Enrique Quiroga-González

    2013-10-01

    Full Text Available Cycling tests under various conditions have been performed for lithium ion battery anodes made from free-standing silicon microwires embedded at one end in a copper current collector. Optimum charging/discharging conditions have been found for which the anode shows negligible fading (< 0.001% over 80 cycles; an outstanding result for this kind of anodes. Several performance parameters of the anode have been compared to the ones of other Si anode concepts, showing that especially the capacity as well as the rates of charge flow per nominal area of anode are the highest for the present anode. With regard to applications, the specific parameters per area are more important than the specific gravimetric parameters like the gravimetric capacity, which is good for comparing the capacity between materials but not enough for comparing between anodes.

  6. A dimensionally stable and fast-discharging graphite-silicon composite Li-ion battery anode enabled by electrostatically self-assembled multifunctional polymer-blend coating.

    Science.gov (United States)

    Li, Fu-Sheng; Wu, Yu-Shiang; Chou, Jackey; Wu, Nae-Lih

    2015-05-18

    A high-performance graphite-Si composite anode for Li-ion batteries containing Si nanoparticles (NPs) attached onto graphite microparticles was synthesized by adopting a polymer-blend of poly(diallyl dimethyl-ammonium chloride) and poly(sodium 4-styrenesulfonate). The polymer-blend enabled uniform distribution of Si NPs during synthesis and served as a robust artificial solid-electrolyte interphase that substantially enhanced the cycle stability and rate performance of the composite electrode. The electrode exhibited a specific capacity of 450 mA h g(-1), 96% capacity retention at a 10 C-rate, 95% retention after 200 cycles, and the same electrode expansion behavior as a pristine graphite electrode.

  7. Bi{sub 1−x}Nb{sub x}O{sub 1.5+x} (x=0.0625, 0.12) fast ion conductors: Structures, stability and oxide ion migration pathways

    Energy Technology Data Exchange (ETDEWEB)

    Tate, Matthew L. [Department of Chemistry, Durham University, Science Site, South Road, Durham DH1 3LE (United Kingdom); Australian Nuclear Science and Technology Organisation, Lucas Heights 2234, NSW (Australia); Hack, Jennifer [Department of Chemistry, Durham University, Science Site, South Road, Durham DH1 3LE (United Kingdom); Institut Laue-Langevin, Grenoble (France); Kuang, Xiaojun [Department of Chemistry, Durham University, Science Site, South Road, Durham DH1 3LE (United Kingdom); McIntyre, Garry J. [Australian Nuclear Science and Technology Organisation, Lucas Heights 2234, NSW (Australia); Withers, Ray L. [Research School of Chemistry, Australian National University, Canberra, ACT (Australia); Johnson, Mark R. [Institut Laue-Langevin, Grenoble (France); Radosavljevic Evans, Ivana, E-mail: ivana.radosavljevic@durham.ac.uk [Department of Chemistry, Durham University, Science Site, South Road, Durham DH1 3LE (United Kingdom); Australian Nuclear Science and Technology Organisation, Lucas Heights 2234, NSW (Australia)

    2015-05-15

    A combined experimental and computational study of Bi{sub 1−x}Nb{sub x}O{sub 1.5+x} (x=0.0625 and 0.12) has been carried out using laboratory X-ray, neutron and electron diffraction, impedance measurements and ab-initio molecular dynamics. We demonstrate that Bi{sub 0.9375}Nb{sub 0.0625}O{sub 1.5625}, previously reported to adopt a cubic fluorite-type superstructure, can form two different polymorphs depending on the synthetic method: a metastable cubic phase is produced by quenching; while slower cooling yields a stable material with a tetragonal √2×√2×1 superstructure, which undergoes a reversible phase transition into the cubic form at ~680 °C on subsequent reheating. Neutron diffraction reveals that the tetragonal superstructure arises mainly from ordering in the oxygen sublattice, with Bi and Nb remaining disordered, although structured diffuse scattering observed in the electron diffraction patterns suggests a degree of short-range ordering. Both materials are oxide ion conductors. On thermal cycling, Bi{sub 0.88}Nb{sub 0.12}O{sub 1.62} exhibits a decrease in conductivity of approximately an order of magnitude due to partial transformation into the tetragonal phase, but still exhibits conductivity comparable to yttria-stabilised zirconia (YSZ). Ab-initio molecular dynamics simulations performed on Bi{sub 0.9375}Nb{sub 0.0625}O{sub 1.5625} show that oxide ion diffusion occurs by O{sup 2−} jumps between edge- and corner-sharing OM{sub 4} groups (M=Bi, Nb) via tetrahedral □M{sub 4} and octahedral □M{sub 6} vacancies. - Graphical abstract: Oxide ion migration in tetragonal Bi{sub 0.9375}Nb{sub 0.0625}O{sub 1.5625} occurs by O{sup 2−} jumps between edge- and corner-sharing OM{sub 4} groups (M=Bi, Nb) via tetrahedral M{sub 4} and octahedral M{sub 6} vacancies. - Highlights: • Bi{sub 0.9375}Nb{sub 0.0625}O{sub 1.5625} adopts a tetragonal √2×√2×1 fluorite superstructure. • Superstructure is due to ordering in the O-sublattice, with Bi

  8. Miniaturised ion mobility spectrometer for fast identification of airborne pollutants - IMS. Final report; Miniaturisiertes Ionenmobilitaetsspektrometer zur Schnellidentifizierung von Schadstoffen in Luft - IMS. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bensch, H.; Baldauf, D.; Hoefer, B.; Mischke, H.; Roesel, G.

    2003-12-01

    Ion mobility spectrometers (IMS) are highly sensitive instruments for monitoring airborne pollution. Portable types with low mass are commercially available already, but the cost so far has been too high for general acceptance. It was investigated how alternative microsystem technologies may make construction and production more efficient. The standard quality parameters of the system were reached. The following key modules were investigated: Sensor (drift cell in particular), inlet, power supply, and microprocessor. Further investigations of potential influencing parameters or system parameters were necessary in order to make the system reproducible. Prototypes were constructed and tested using different technologies. (orig.) [German] Ionenmobilitaetsspektrometer (IMS) stellen hochempfindliche Messgeraete fuer Verunreinigungen in der Luft dar. Portable Geraete mit geringer Masse sind bereits kommerziell erhaeltlich. Relativ hohe Preise fuer solche Geraete verhindern jedoch einen breiten Einsatz. Es wurde untersucht, wie durch alternative (mikrosystemtechnische) Ansaetze eine effizientere Konstruktion und Ferigung erreicht werden kann. Die Qualitaetsparameter des Systems werden zumindest wieder erreicht. Folgende Kernbaugruppen wurden untersucht: Sensor (insbesodere Driftzelle), Einlassteil, Energieversorgung und Mikrorechner. Um eine Reproduzierbarkeit des Systems zu gewaehrleisten, waren zusaetzliche Untersuchungen zu moeglichen Einflussgroessen bzw. Systemparametern notwendig. Durch den Einsatz unterschiedlichster Technologien wurden Prototypen eines neuen Geraetes gefertigt und getestet. (orig.)

  9. Investigation of the interference effect in the case of low energy electron emission from O2 in collisions with fast bare C-ions

    Science.gov (United States)

    Nandi, Saikat; Agnihotri, A. N.; Tachino, C. A.; Rivarola, R. D.; Martín, F.; Tribedi, Lokesh C.

    2012-11-01

    We have measured the double differential cross sections (DDCSs) for low energy electron emission from O2 under the impact of 51 MeV bare carbon ions. This study is aimed at investigating the Young-type interference in electron emission from a multi-electronic diatomic molecule. The DDCS spectra, differential in emission energy and angle, are compared with state-of-the-art continuum distorted wave-eikonal initial state (CDW-EIS) calculations. The DDCS ratios (i.e. O2/2O) do not produce any oscillatory behaviour due to the interference effect unlike that observed in the case of H2. The forward-backward angular asymmetry parameter, deduced from the measured DDCS values, is found to be a monotonically increasing function of electron velocity and does not show any oscillation. These observations are in qualitative agreement with the prediction of the molecular CDW-EIS model which uses a linear combination of atomic orbitals. The apparent absence of the oscillation in the spectra is qualitatively explained in terms of cancellation of contributions arising from different molecular orbitals.

  10. Investigation of the interference effect in the case of low energy electron emission from O2 in collisions with fast bare C-ions

    International Nuclear Information System (INIS)

    Nandi, Saikat; Agnihotri, A N; Tribedi, Lokesh C; Tachino, C A; Rivarola, R D; Martín, F

    2012-01-01

    We have measured the double differential cross sections (DDCSs) for low energy electron emission from O 2 under the impact of 51 MeV bare carbon ions. This study is aimed at investigating the Young-type interference in electron emission from a multi-electronic diatomic molecule. The DDCS spectra, differential in emission energy and angle, are compared with state-of-the-art continuum distorted wave-eikonal initial state (CDW-EIS) calculations. The DDCS ratios (i.e. O 2 /2O) do not produce any oscillatory behaviour due to the interference effect unlike that observed in the case of H 2 . The forward-backward angular asymmetry parameter, deduced from the measured DDCS values, is found to be a monotonically increasing function of electron velocity and does not show any oscillation. These observations are in qualitative agreement with the prediction of the molecular CDW-EIS model which uses a linear combination of atomic orbitals. The apparent absence of the oscillation in the spectra is qualitatively explained in terms of cancellation of contributions arising from different molecular orbitals.

  11. Ion-Exchange Sample Displacement Chromatography as a Method for Fast and Simple Isolation of Low- and High-Abundance Proteins from Complex Biological Mixtures

    Directory of Open Access Journals (Sweden)

    Martina Srajer Gajdosik

    2014-01-01

    Full Text Available Sample displacement chromatography (SDC in reversed phase and ion-exchange modes was introduced at the end of 1980s. This chromatographic method was first used for preparative purification of synthetic peptides, and subsequently adapted for protein fractionation, mainly in anion-exchange mode. In the past few years, SDC has been successfully used for enrichment of low- and medium-abundance proteins from complex biological fluids on both monolithic and bulk chromatographic supports. If aqueous mobile phase is used with the application of mild chromatographic conditions, isolated proteins are not denatured and can also keep their biological activity. In this paper, the use of SDC in anion-exchange mode on a high-capacity chromatographic resin for separation of proteins from complex biological mixtures such as human plasma is demonstrated. By use of three and more columns coupled in series during sample application, and subsequent parallel elution of detached columns, additional separation of bound proteins was achieved. Highly enriched human serum albumin fraction and a number of physiologically active medium- and low-abundance proteins could be fractionated and detected by electrospray ionization tandem mass spectrometry (ESI-MS/MS and matrix assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS. The use of the aforementioned columns that can be sanitized with 1 M sodium hydroxide for further application of SDC in biotechnology and food technology was discussed.

  12. Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)

    2007-09-15

    Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  13. HEAVY ION FUSION SCIENCE VIRTUAL NATIONAL LABORATORY 1ST QUARTER 2010 MILESTONE REPORT: Simulations of fast correction of chromatic aberrations to establish physics specifications for implementation on NDCX-1 and NDCX-2

    International Nuclear Information System (INIS)

    Lidia, S.M.; Lund, S.M.; Seidl, P.A.

    2010-01-01

    This milestone has been accomplished. The Heavy Ion Fusion Science Virtual National Laboratory has completed simulations of a fast correction scheme to compensate for chromatic and time-dependent defocusing effects in the transport of ion beams to the target plane in the NDCX-1 facility. Physics specifications for implementation in NDCX-1 and NDCX-2 have been established. This milestone has been accomplished. The Heavy Ion Fusion Science Virtual National Laboratory has completed simulations of a fast correction scheme to compensate for chromatic and time-dependent defocusing effects in the transport of ion beams to the target plane in the NDCX-1 facility. Physics specifications for implementation in NDCX-1 and NDCX-2 have been established. Focal spot differences at the target plane between the compressed and uncompressed regions of the beam pulse have been modeled and measured on NDCX-1. Time-dependent focusing and energy sweep from the induction bunching module are seen to increase the compressed pulse spot size at the target plane by factors of two or more, with corresponding scaled reduction in the peak intensity and fluence on target. A time-varying beam envelope correction lens has been suggested to remove the time-varying aberration. An Einzel (axisymmetric electric) lens system has been analyzed and optimized for general transport lines, and as a candidate correction element for NDCX-1. Attainable high-voltage holdoff and temporal variations of the lens driving waveform are seen to effect significant changes on the beam envelope angle over the duration of interest, thus confirming the utility of such an element on NDCX-1. Modeling of the beam dynamics in NDCX-1 was performed using a time-dependent (slice) envelope code and with the 3-D, self-consistent, particle-in-cell code WARP. Proof of concept was established with the slice envelope model such that the spread in beam waist positions relative to the target plane can be minimized with a carefully designed

  14. Solid-State Modulators for RF and Fast Kickers

    CERN Document Server

    Cook, Edward; Brooksby, Craig A; Cassel, Richard; De Lamare, Jeffrey E; Gower, Edward J; Hawkins, Steven; Hickman, Bradley C; Nguyen, Minh N; Pappas, Chris

    2005-01-01

    As the capabilities of solid-state devices increase, these devices are being incorporated into modulator designs for high voltage accelerator applications. Solid-state modulators based on inductive adder circuit topology have demonstrated great versatility with regard to pulse width and pulse repetition rate while maintaining fast pulse rise and fall times. Additionally, these modulators are capable of being scaled to higher output voltage and power levels. An explanation of the basic circuit operation will be presented as well as test data of several different hardware systems.

  15. Operator care and eco-concerned development of a fast, facile and economical assay for basic nitrogenous drugs based on simplified ion-pair mini-scale extraction using safer solvent combined with drop-based spectrophotometry.

    Science.gov (United States)

    Plianwong, Samarwadee; Sripattanaporn, Areerut; Waewsa-nga, Kwanrutai; Buacheen, Parin; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak

    2012-08-30

    A fast, facile, and economical assay for basic nitrogenous drugs has been developed based on the mini-scale extraction of the drug-dye ion pair complex combined with the use of safe-for-analyst and eco-friendlier organic extractant and drop-based micro-spectrophotometry. Instead of using large volume devices, the extraction was simply carried out in typical 1.5 mL microcentrifuge tubes along with the use of micropipettes for accurate transfer of liquids, vortex mixer for efficient partitioning of solutes and benchtop centrifuge for rapid phase separation. In the last step, back-extraction was performed by using the microvolume of acidic solution in order to concentrate the colored species into a confined aqueous microdrop and to keep the analyst away from unwanted contact and inhalation of organic solvents during the quantitation step which was achieved by using cuvetteless UV-vis micro-spectrophotometry without any prior dilutions. Using chlorpheniramine maleate as a representative analyte and n-butyl acetate as a less toxic and non-ozone depleting extractant, the miniaturized method was less laborious and much faster. It was accurate, precise and insensitive to the interferences from common excipients. Notably, it gave the assay results of drug in tablets and oral solution comparable to the large-scale pharmacopeial method while the consumption of organic solvents and the release of wastes were lowered by 200-400 folds. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Simultaneous Qualitative and Quantitative Analysis of Multiple Chemical Constituents in YiQiFuMai Injection by Ultra-Fast Liquid Chromatography Coupled with Ion Trap Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Chunhua Liu

    2016-05-01

    Full Text Available YiQiFuMai injection (YQFM is a modern lyophilized powder preparation derived from the traditional Chinese medicine Sheng-mai san (SMS used for treating cardiovascular diseases, such as chronic heart failure. However, its chemical composition has not been fully elucidated, particularly for the preparation derived from Ophiopogon japonicus. This study aimed to establish a systematic and reliable method to quickly and simultaneously analyze the chemical constituents in YQFM by ultra-fast liquid chromatography coupled with ion trap time-of-flight mass spectrometry (UFLC-IT-TOF/MS. Sixty-five compounds in YQFM were tentatively identified by comparison with reference substances or literature data. Furthermore, twenty-one compounds, including three ophiopogonins, fifteen ginsenosides and three lignans were quantified by UFLC-IT-TOF/MS. Notably, this is the first determination of steroidal saponins from O. japonicus in YQFM. The relative standard deviations (RSDs of intra- and inter-day precision, reproducibility and stability were <4.9% and all analytes showed good linearity (R2 ≥ 0.9952 and acceptable recovery of 91.8%–104.2% (RSD ≤ 5.4%, indicating that the methods were reliable. These methods were successfully applied to quantitative analysis of ten batches of YQFM. The developed approach can provide useful and comprehensive information for quality control, further mechanistic studies in vivo and clinical application of YQFM.

  17. Collisionless ion acoustic shocks in a negative-ion plasma

    International Nuclear Information System (INIS)

    Sheridan, T.E.

    1999-01-01

    Plasmas containing positive ions and electrons together with an additional negative component (e.g. negative ions or particulates) are of interest in subfields of plasma physics ranging from basic plasma physics (solitons and shocks, dusty plasmas) to ionospheric and space plasmas to plasma processing (electronegative discharges and particulate contamination). Such plasmas support two modes of the ion acoustic wave, a 'slow' mode where positive ions, negative ions and electrons oscillate in phase, and a 'fast' mode where negative ions oscillate out of phase with the other two components. When nonlinear steepening is considered, the fast wave may form a negative-potential solitary wave (NPSW), which, with the addition of dissipation (e.g. ion reflection, collisions, turbulence, electron Landau damping), will either disperse, or, more interestingly, form a shock. Recently, two experiments on the formation of shocks in a Q-machine plasma with negative ions have been reported. A low-temperature, negative-ion component was created when electrons attached to added SF 6 molecules. In such a plasma, the electron and positive ion temperatures are comparable (∼ 0.2 eV), so that when the negative ion concentration is small (< 50%), ion waves are strongly Landau damped since their phase velocity is comparable to the positive ion thermal velocity. However, a large negative ion concentration increases the phase velocity to a point where damping is weak. Conditions are then right for the formation of a shock. We have simulated shock formation in such a plasma

  18. Ion optics of RHIC EBIS

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y.; Kuznetsov, G.

    2011-09-10

    RHIC EBIS has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

  19. Test fast kicker pulser

    International Nuclear Information System (INIS)

    Zhang, W.; Soukas, A.V.; Zhanf, S.Y.; Frey, W.W.; Bunicci, J.

    1989-01-01

    In this paper, a test pulser of the Brookhaven AGS Booster extraction fast kicker is described. The pulser is projected for both proton and heavy ion operation. A load of total inductance 2.15 μH is used for the test pulser. The PFN voltage is required to be below 40 kV for operation in air. Rise time of the pulse for proton extraction operation is about 120ns up to 97% of full current (1000A), and, for heavy ion extraction, 160ns up to 98% of full current (1615A). R-C compensation networks are used for pulse front edge sharpening. The flexibility of operation is obtained basically by switching an energy dumping resistor to match or mismatch the PFN impedance. Some comments on stray capacitance and stray inductance effects are included. 3 refs., 10 figs., 2 tabs

  20. FAST scan

    DEFF Research Database (Denmark)

    Müller, Anna

    FAST-skanning er en metode, der har til formål at hurtigt diagnosticere fri væske i bughulen hos traumapatienter og andre akutte patienter. Denne skanningsteknik blev først introduceret til hunde i 2004, og omfatter ultralydsskanning af specifikke punkter i bughulen, hvor der er stor chance....../sorte) områder. I dag bruges FAST-skanning meget hyppigt indenfor human og veterinær akutmedicin. Det kan ses som et værktøj for dyrlæger som ikke arbejder med ultralyd til daglig. FAST-skanning har mange fordele; proceduren er effektiv og kan tage under 3 minutter, men har alligevel høj diagnostisk værdi. Det...... nødvendigt. Det skal dog understreges, at de abdominale organer ikke undersøges specifikt. Det kan være svært at skelne mellem væske i peritonealhulen og i det retroperitoneale rum. Man kan heller ikke karakterisere væsken og derved skelne mellem f.eks. blod, pus eller urin. Siden FAST-skanning blev...

  1. Fast ejendom

    DEFF Research Database (Denmark)

    Pagh, Peter

    Bogen omfatter en gennemgang af lovgivning, praksis og teori vedrørende køb af fast ejendom og offentligretlig og privatretlig regulering. Bogen belyser bl.a. de privatretlige emner: købers misligholdelsesbeføjelser, servitutter, naboret, hævd og erstatningsansvar for miljøskader samt den...

  2. ITER Fast Ion Collective Thomson Scattering

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Meo, Fernando; Korsholm, Søren Bang

    for measurements of the confined fusion alpha particles in ITER set by the ITER team. Then we outline the considerations, which enter into the selection and evaluation of CTS systems. System definition includes choice of probe frequency, geometry of probe and receiver beam patterns and probe power, but ultimately...

  3. FISICO: Fast Image SegmentatIon COrrection.

    Directory of Open Access Journals (Sweden)

    Waldo Valenzuela

    Full Text Available In clinical diagnosis, medical image segmentation plays a key role in the analysis of pathological regions. Despite advances in automatic and semi-automatic segmentation techniques, time-effective correction tools are commonly needed to improve segmentation results. Therefore, these tools must provide faster corrections with a lower number of interactions, and a user-independent solution to reduce the time frame between image acquisition and diagnosis.We present a new interactive method for correcting image segmentations. Our method provides 3D shape corrections through 2D interactions. This approach enables an intuitive and natural corrections of 3D segmentation results. The developed method has been implemented into a software tool and has been evaluated for the task of lumbar muscle and knee joint segmentations from MR images.Experimental results show that full segmentation corrections could be performed within an average correction time of 5.5±3.3 minutes and an average of 56.5±33.1 user interactions, while maintaining the quality of the final segmentation result within an average Dice coefficient of 0.92±0.02 for both anatomies. In addition, for users with different levels of expertise, our method yields a correction time and number of interaction decrease from 38±19.2 minutes to 6.4±4.3 minutes, and 339±157.1 to 67.7±39.6 interactions, respectively.

  4. FISICO: Fast Image SegmentatIon COrrection.

    Science.gov (United States)

    Valenzuela, Waldo; Ferguson, Stephen J; Ignasiak, Dominika; Diserens, Gaëlle; Häni, Levin; Wiest, Roland; Vermathen, Peter; Boesch, Chris; Reyes, Mauricio

    2016-01-01

    In clinical diagnosis, medical image segmentation plays a key role in the analysis of pathological regions. Despite advances in automatic and semi-automatic segmentation techniques, time-effective correction tools are commonly needed to improve segmentation results. Therefore, these tools must provide faster corrections with a lower number of interactions, and a user-independent solution to reduce the time frame between image acquisition and diagnosis. We present a new interactive method for correcting image segmentations. Our method provides 3D shape corrections through 2D interactions. This approach enables an intuitive and natural corrections of 3D segmentation results. The developed method has been implemented into a software tool and has been evaluated for the task of lumbar muscle and knee joint segmentations from MR images. Experimental results show that full segmentation corrections could be performed within an average correction time of 5.5±3.3 minutes and an average of 56.5±33.1 user interactions, while maintaining the quality of the final segmentation result within an average Dice coefficient of 0.92±0.02 for both anatomies. In addition, for users with different levels of expertise, our method yields a correction time and number of interaction decrease from 38±19.2 minutes to 6.4±4.3 minutes, and 339±157.1 to 67.7±39.6 interactions, respectively.

  5. Fast-scintillator measurements

    International Nuclear Information System (INIS)

    Graves, W.R.; Slaughter, D.R.; Lerche, R.A.

    1985-01-01

    The authors are investigating scintillators because their fast timing properties may be applied to the development of neutron diagnostics. Measuring the history of a target burn by direct observation of DT neutrons requires a time resolution of 20 ps. An instrument designed to measure the plasma ion temperature by neutron time of flight, when the flight path is less than or equal to 1m, requires a detector system with resolution of 60 to 100 ps. Fast plastic scintillators like NE111, BC-422, and SG180 typically have decay constants of about 1400 ps. With quenching, the decay constant can be decreased to about 700 ps - still to slow for the instruments that they would like to build. One yet-unexploited property of fast scintillators is their rise time. In 1984, they began experiments designed to measure scintillator rise times. For our application - the measurement of target burn histories - they are especially concerned with the temporal width of the sample excitation pulse, the temporal resolution of our measurement system, and the need to characterize the excitation pulse and the scintillator output simultaneously. Application of plastic scintillators to a neutron streak camera is described

  6. Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath. II. Towards a first principles theory

    Science.gov (United States)

    Auluck, S. K. H.

    2017-11-01

    This paper continues earlier discussion [S. K. H. Auluck, Phys. Plasmas 21, 102515 (2014)] concerning the formulation of conservation laws of mass, momentum, and energy in a local curvilinear coordinate system in the dense plasma focus. This formulation makes use of the revised Gratton-Vargas snowplow model [S. K. H. Auluck, Phys. Plasmas 20, 112501 (2013)], which provides an analytically defined imaginary surface in three dimensions which resembles the experimentally determined shape of the plasma. Unit vectors along the local tangent to this surface, along the azimuth, and along the local normal define a right-handed orthogonal local curvilinear coordinate system. The simplifying assumption that physical quantities have significant variation only along the normal enables writing laws of conservation of mass, momentum, and energy in the form of effectively one-dimensional hyperbolic conservation law equations using expressions for various differential operators derived for this coordinate system. This formulation demonstrates the highly non-trivial result that the axial magnetic field and toroidally streaming fast ions, experimentally observed by multiple prestigious laboratories, are natural consequences of conservation of mass, momentum, and energy in the curved geometry of the dense plasma focus current sheath. The present paper continues the discussion in the context of a 3-region shock structure similar to the one experimentally observed: an unperturbed region followed by a hydrodynamic shock containing some current followed by a magnetic piston. Rankine-Hugoniot conditions are derived, and expressions are obtained for the specific volumes and pressures using the mass-flux between the hydrodynamic shock and the magnetic piston and current fraction in the hydrodynamic shock as unknown parameters. For the special case of a magnetic piston that remains continuously in contact with the fluid being pushed, the theory gives closed form algebraic results for the

  7. A review of recoil ion physics

    International Nuclear Information System (INIS)

    Gray, T.D.; Cocke, C.L.

    1983-01-01

    A review of recoil ion physics is presented. A brief history on the subject is introduced. The production of low velocity highly-charged recoil ions by fast heavy ion beams is discussed. Experiments which utilize the LEHQ beams to measure charge exchange cross sections and energy gain spectroscopy are discussed

  8. The mean excitation energy of atomic ions

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Oddershede, Jens; Sabin, John R.

    2015-01-01

    A method for calculation of the mean excitation energies of atomic ions is presented, making the calculation of the energy deposition of fast ions to plasmas, warm, dense matter, and complex biological systems possible. Results are reported to all ions of helium, lithium, carbon, neon, aluminum...

  9. Secondary ion emission from surface and volume with high and low energy ions

    International Nuclear Information System (INIS)

    Deprun, C.; Della-Negra, S.; Le Beyec, Y.

    1987-01-01

    Secondary ion emission from fast ion impact (Cf252 fission fragments) of Langmuir-Blodgett films consisting of superposed two molecule layers with similar structure and mass (Cd stereate and Cd arachidate) was analyzed. Emission of deproton secondary ions of stereate and arachidate acids was studied for various target configurations. Results show that under the influence of high energy ions, secondary ion ejection comes from a conical volume of 200A depth [fr

  10. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, O. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D. [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  11. Resonance Ionization Laser Ion Sources

    CERN Document Server

    Marsh, B

    2013-01-01

    The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

  12. Fast self-diffusion of ions in CH 3 NH 3 PbI 3 : the interstiticaly mechanism versus vacancy-assisted mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ji-Hui; Yin, Wan-Jian; Park, Ji-Sang; Wei, Su-Huai

    2016-01-01

    The stability of organic-inorganic halide perovskites is a major challenge for their applications and has been extensively studied. Among the possible underlying reasons, ion self-diffusion has been inferred to play important roles. While theoretical studies congruously support that iodine is more mobile, experimental studies only observe the direct diffusion of the MA ion and possible diffusion of iodine. The discrepancy may result from the incomplete understanding of ion diffusion mechanisms. With the help of first-principles calculations, we studied ion diffusion in CH3NH3PbI3 (MAPbI3) through not only the vacancy-assisted mechanisms presumed in previous theoretical studies, but also the neglected interstiticaly mechanisms. We found that compared to the diffusion through the vacancy-assisted mechanism, MA ion diffusion through the interstiticaly mechanism has a much smaller barrier which could explain experimental observations. For iodine diffusion, both mechanisms can yield relatively small barriers. Depending on the growth conditions, defect densities of vacancies and interstitials can vary and so do the diffusion species as well as diffusion mechanisms. Our work thus supports that both MA and iodine ion diffusion could contribute to the performance instability of MAPbI3. While being congruous with experimental results, our work fills the research gap by providing a full understanding of ion diffusion in halide perovskites.

  13. Some fast beam kicker magnet systems at SLAC

    International Nuclear Information System (INIS)

    Bulos, F.; Cassel, R.L.; Donaldson, A.R.

    1987-01-01

    The Stanford Linear Collider requires very fast rise and fall times from its kicker magnets. The damping rings and positron source need either one or two bunches deflected from two or three that are separated in time by about 59 ns. The final focus region kicker magnets need a rise time of less than 700 ns and each one deflects only one bunch. This paper discusses the design and characteristics of a thyratron-switched, castor-oil-filled, coaxial, Blumlein line used for one bunch kicking. It discharges a 118 ns (at the base), 50 kV, 3 kA pulse into a 33 cm long, ferrite-loaded, kicker magnet of rectangular coaxial-line geometry, which in turn is terminated by a matched load. Reference is made to a Fermilab (FNAL) designed magnet and a dual-thyratron pulsar that will deflect two serial bunches in or out of the electron ring. Also, a brief description of the final focus magnet is given. Work is continuing on the various subsystem components to decrease the pulse rise and fall time, flattop ripple and jitter and to reduce some of the sources of noise and hv breakdown

  14. Fast Convolution Module (Fast Convolution Module)

    National Research Council Canada - National Science Library

    Bierens, L

    1997-01-01

    This report describes the design and realisation of a real-time range azimuth compression module, the so-called 'Fast Convolution Module', based on the fast convolution algorithm developed at TNO-FEL...

  15. Laser-Cooling for Light Ion Accumulation

    CERN Document Server

    Madsen, N

    2000-01-01

    The ALICE Experiment to be installed at the Large Hadron Collider (LHC) will initially look at Pb82+-Pb82+ collisions. In a later stage, collisions of lighter ions are also foreseen. For lead ions, fast electron cooling will be used in the accumulation process at low energy to reach the beam brightness necessary for the experiment. For lighter ions, electron cooling becomes less efficient as the ratio Q2/A decreases (Q and A are respectively charge state and mass number of the ion). For this reason, a study has been made of the possibility to use the maturing technology of laser-cooling of fast ion beams to reach the desired emittances for lighter ions. The main problems encountered are the availability of useful ion species, the availability of corresponding laser systems, and the efficiency with which the transverse emittance can be reduced by the laser-cooling mechanism (which works mainly in the longitudinal plane).

  16. Low-altitude ion heating with downflowing and upflowing ions

    Science.gov (United States)

    Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; James, G.; Miles, D.; Cogger, L. L.; Perry, G. W.

    2017-12-01

    Mechanisms that energize ions at the initial stage of ion upflow are still not well understood. We statistically investigate ionospheric ion energization and field-aligned motion at very low altitudes (330-730 km) using simultaneous plasma, magnetic field, wave electric field and optical data from the e-POP satellite. The high-time-resolution (10 ms) dataset enables us to study the micro-structures of ion heating and field-aligned ion motion. The ion temperature and field-aligned bulk flow velocity are derived from 2-D ion distribution functions measured by the SEI instrument. From March 2015 to March 2016, we've found 17 orbits (in total 24 ion heating periods) with clear ion heating signatures passing across the dayside cleft or the nightside auroral regions. Most of these events have consistent ion heating and flow velocity characteristics observed from both the SEI and IRM instruments. The perpendicular ion temperature goes up to 4.5 eV within a 2 km-wide region in some cases, in which the Radio Receiver Instrument (RRI) sees broadband extremely low frequency (BBELF) waves, demonstrating significant wave-ion heating down to as low as 350 km. The e-POP Fast Auroral Imager (FAI) and Magnetic Field (MGF) instruments show that many events are associated with active aurora and are within downward current regions. Contrary to what would be expected from mirror-force acceleration of heated ions, the majority of these heating events (17 out of 24) are associated with the core ion downflow rather than upflow. These statistical results provide us with new sights into ion heating and field-aligned flow processes at very low altitudes.

  17. High power fast ramping power supplies

    Energy Technology Data Exchange (ETDEWEB)

    Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.

    2009-05-04

    Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.

  18. Enhanced Model for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Rodney J. [Research Applications Corporation, Los Alamos, NM (United States)

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  19. 2010 ion run: completed!

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    After a very fast switchover from protons to lead ions, the LHC has achieved performances that allowed the machine to exceed both peak and integrated luminosity by a factor of three. Thanks to this, experiments have been able to produce high-profile results on ion physics almost immediately, confirming that the LHC was able to keep its promises for ions as well as for protons.   First direct observation of jet quenching. A seminar on 2 December was the opportunity for the ALICE, ATLAS and CMS collaborations to present their first results on ion physics in front of a packed auditorium. These results are important and are already having a major impact on the understanding of the physics processes that involve the basic constituents of matter at high energies. In the ion-ion collisions, the temperature is so high that partons (quarks and gluons), which are usually constrained inside the nucleons, are deconfined to form a highly dense and hot soup known as quark-gluon plasma (QGP). The existence of ...

  20. Structural characterization and complex impedance studies on fast ...

    Indian Academy of Sciences (India)

    This paper deals with preparation and physico-chemical characterization of a new mixed system, (SbI3)–(Ag2CrO4)1− (0.1 ≤ ≤ 0.9), undertaken with a view to evaluate silver ion transport properties and identify those fast ion conducting compositions. Polycrystalline samples of various compositions were synthesized ...

  1. Ion energy distributions and sidewall profiles in reactive ion etching

    International Nuclear Information System (INIS)

    May, P.W.; Field, D.; Klemperer, D.F.; Song, Y.P.

    1993-01-01

    We present a brief resume of modelling of ion trajectories in radio frequency discharges of interest in reactive ion etching of semiconductors. The procedures for calculating the energies and angles at which ions strike the substrate surface are described. Examples of ion energy distributions (IEDs) and angular distributions (IADs) are given both for low pressure, collisionless-sheath plasmas, and for higher pressure conditions, where collisions significantly modify ion trajectories. Fast neutral particles formed in the sheath by collision processes are also considered. Computer modelling of the evolution of sidewall profiles during etch processes is discussed, and examples are given of profiles calculated using IED and IAD data both at low and high pressures. (orig.)

  2. Application of solvent-assisted dispersive solid phase extraction as a new, fast, simple and reliable preconcentration and trace detection of lead and cadmium ions in fruit and water samples.

    Science.gov (United States)

    Behbahani, Mohammad; Ghareh Hassanlou, Parmoon; Amini, Mostafa M; Omidi, Fariborz; Esrafili, Ali; Farzadkia, Mehdi; Bagheri, Akbar

    2015-11-15

    In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SA-DSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by flame atomic absorption spectrophotometer. Under the optimized conditions, the detection limit for lead and cadmium ions was 1.2 μg L(-1) and 0.2 μg L(-1), respectively. Furthermore, the preconcentration factor was 299.3 and 137.1 for cadmium and lead ions, respectively. SA-DSPE was successfully applied for trace determination of lead and cadmium in fruit (Citrus limetta, Kiwi and pomegranate) and water samples. Finally, the introduced sample preparation method can be used as a simple, rapid, reliable, selective and sensitive method for flame atomic absorption spectrophotometric determination of trace levels of lead and cadmium ions in fruit and water samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The AGS accelerator complex with the new fast extraction system

    International Nuclear Information System (INIS)

    Tanaka, M.; Bleser, E.J.; Glenn, J.W.; Lee, Y.Y.; Soukas, A.

    1995-01-01

    The delivery of a beam with characteristics appropriate for the g-2 muon storage ring and the filling of the RHIC heavy ion collider from the AGS main ring requires a new fast extracted beam (FEB) system. The new FEB system will be capable of performing both one-turn fast extraction and single bunch multiple extraction of either a heavy ion beam or a high intensity proton beam at a rate of 30 Hz up to 12 times per AGS cycle. The new system consists of a fast multi-pulsing kicker and an ejector septum magnet with local extraction orbit bumps

  4. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  5. Acid-fast stain

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003766.htm Acid-fast stain To use the sharing features on this page, please enable JavaScript. The acid-fast stain is a laboratory test that determines ...

  6. Fast food (image)

    Science.gov (United States)

    Fast foods are quick, reasonably priced, and readily available alternatives to home cooking. While convenient and economical for a busy lifestyle, fast foods are typically high in calories, fat, saturated fat, ...

  7. Fast food tips (image)

    Science.gov (United States)

    ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ...

  8. Dosimetry and radiobiology of negative pions and heavy ions

    International Nuclear Information System (INIS)

    Raju, M.R.

    1978-01-01

    The depth dose distribution of pion beams has not been found superior to protons. Pion radiation quality at the plateau region is comparable to conventional low-LET radiations, and radiobiology results also indicate RBE values close to unity. In the pion stopping region, the radiation quality increases considerably. Radiobiology data for negative pions at the Bragg peak position clearly indicate the increase in RBE and the reduction in OER. Even at the Bragg peak position, compared to fast neutrons, the average LET of negative pions is lower. Pion radiobiology data have indicated lower RBE values and higher OER values compared to fast neutrons. The radiation quality of fast neutrons is in between that of carbon and neon ions at the peak region and that of neon ions at the plateau is lower than for fast neutrons. The mean LET value for helium ions, even at the distal end of the peak, is lower than for fast neutrons. Dose localization of heavy ions has been found to decrease slowly with increasing charge of the heavy ion. The intercellular contact that protects cells after exposure to low-LET radiations is not detected after exposure to heavy ions. Single and fractionated doses of heavy ions produce dose-response curves for heavy ions having reduced shoulders but similar slopes when compared to gamma rays. Fractionated treatments of heavy ions produce an enhanced effect in the peak region compared to the plateau region and could lead to a substantial gain in therapeutic ratio. The OER for protons was similar to that for x rays. The OER values for negative pions, helium ions, and carbon ions were larger, for neon ions similar, and for argon ions smaller when compared to fast neutrons.Negative pions, helium ions, and carbon ions may be very effective clinically because the radiation quality of these beams is similar to that of the mixed scheme of neutrons and x rays

  9. Physiology of Ramadan fasting

    OpenAIRE

    Shokoufeh Bonakdaran

    2016-01-01

    Considering the emphasis of Islam on the importance of fasting, Muslims attempt to fast from dawn until sunset during the holy month of Ramadan. Fasting is associated with several benefits for normal and healthy individuals. However, it could pose high risks to the health of diabetic patients due to certain physiological changes. This study aimed to compare the physiological changes associated with fasting in healthy individuals and diabetic patients during Ramadan. Furthermore, we reviewed t...

  10. Ramadan, fasting and pregnancy

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery...

  11. Development of a thermal ionizer as ion catcher

    NARCIS (Netherlands)

    Traykov, E.; Dammalapati, U.; De, S.; Dermois, O. C.; Huisman, L.; Jungmann, K.; Kruithof, W.; Mol, A. J.; Onderwater, C. J. G.; Rogachevskiy, A.; da Silva e Silva, M.; Sohani, M.; Versolato, O.; Willmann, L.; Wilschut, H. W.

    2008-01-01

    An effective ion catcher is all important part of a radioactive beam Facility that is based on in-flight production. The catcher stops fast radioactive products and emits them as singly charged slow ions. Current ion catchers are based on stopping in He and H-2 gas. However, with increasing

  12. Ramadan, faste og graviditet

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery......, but there are reports of decreased foetal movements. Furthermore, the fasting may have long-term health consequences for the offspring, especially when they reach their middle age. According to Islam and the interpretation, pregnant and breast-feeding women are allowed to postpone the fasting of the month of Ramadan...

  13. Ion colliders

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  14. Ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  15. A measurement of the response to fast neutrons of several materials dosemeters

    International Nuclear Information System (INIS)

    Jones, L.T.; Kitching, S.J.; Lewis, T.A.; Playle, T.S.

    1986-07-01

    The response to fast neutrons was measured for three types of materials testing dosemeters: fast neutron dosimetry silicon diodes; beryllia, alumina and calcium fluoride TLDs; graphite walled ionisation chambers. The calibrations were made using a 3MW positive ion accelerator. The arrangement of the target, beam monitor and devices is described, and the measured fast neutron sensitivities are presented. (UK)

  16. An Aqueous Ca-Ion Battery.

    Science.gov (United States)

    Gheytani, Saman; Liang, Yanliang; Wu, Feilong; Jing, Yan; Dong, Hui; Rao, Karun K; Chi, Xiaowei; Fang, Fang; Yao, Yan

    2017-12-01

    Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anode and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.

  17. Design of a Solid-State Fast Voltage Compensator for klystron modulators requiring constant AC power consumption

    CERN Document Server

    Aguglia, Davide; Viarouge, Philippe; Cros, Jerome

    2014-01-01

    This paper proposes a novel topological solution for klystron modulators integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This kind of solution is mandatory for the CLIC project under study, which requires several hundreds of synchronously operated klystron modulators for a total pulsed power of 39 GW. The topology is optimized for the challenging CLIC specifications, which require a very precise output voltage flat-top as well as fast rise and fall times (3µs). The Fast Voltage Compensator is integrated in the modulator such that it only has to manage the capacitor charger current and a fraction of the charging voltage. Consequently, its dimensioning power and cost is minimized.

  18. ion irradiation

    Indian Academy of Sciences (India)

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in ...

  19. A Simple Defined Medium for the Production of True Diketopiperazines in Xylella fastidiosa and Their Identification by Ultra-Fast Liquid Chromatography-Electrospray Ionization Ion Trap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Michelli Massaroli da Silva

    2017-06-01

    Full Text Available Diketopiperazines can be generated by non-enzymatic cyclization of linear dipeptides at extreme temperature or pH, and the complex medium used to culture bacteria and fungi including phytone peptone and trypticase peptone, can also produce cyclic peptides by heat sterilization. As a result, it is not always clear if many diketopiperazines reported in the literature are artifacts formed by the different complex media used in microorganism growth. An ideal method for analysis of these compounds should identify whether they are either synthesized de novo from the products of primary metabolism and deliver true diketopiperazines. A simple defined medium (X. fastidiosa medium or XFM containing a single carbon source and no preformed amino acids has emerged as a method with a particularly high potential for the grown of X. fastidiosa and to produce genuine natural products. In this work, we identified a range of diketopiperazines from X. fastidiosa 9a5c growth in XFM, using Ultra-Fast Liquid Chromatography coupled with mass spectrometry. Diketopiperazines are reported for the first time from X. fastidiosa, which is responsible for citrus variegated chlorosis. We also report here fatty acids from X. fastidiosa, which were not biologically active as diffusible signals, and the role of diketopiperazines in signal transduction still remains unknown.

  20. A Simple Defined Medium for the Production of True Diketopiperazines in Xylella fastidiosa and Their Identification by Ultra-Fast Liquid Chromatography-Electrospray Ionization Ion Trap Mass Spectrometry.

    Science.gov (United States)

    Silva, Michelli Massaroli da; Andrade, Moacir Dos Santos; Bauermeister, Anelize; Merfa, Marcus Vinícius; Forim, Moacir Rossi; Fernandes, João Batista; Vieira, Paulo Cezar; Silva, Maria Fátima das Graças Fernandes da; Lopes, Norberto Peporine; Machado, Marcos Antônio; Souza, Alessandra Alves de

    2017-06-13

    Diketopiperazines can be generated by non-enzymatic cyclization of linear dipeptides at extreme temperature or pH, and the complex medium used to culture bacteria and fungi including phytone peptone and trypticase peptone, can also produce cyclic peptides by heat sterilization. As a result, it is not always clear if many diketopiperazines reported in the literature are artifacts formed by the different complex media used in microorganism growth. An ideal method for analysis of these compounds should identify whether they are either synthesized de novo from the products of primary metabolism and deliver true diketopiperazines. A simple defined medium ( X. fastidiosa medium or XFM) containing a single carbon source and no preformed amino acids has emerged as a method with a particularly high potential for the grown of X. fastidiosa and to produce genuine natural products. In this work, we identified a range of diketopiperazines from X. fastidiosa 9a5c growth in XFM, using Ultra-Fast Liquid Chromatography coupled with mass spectrometry. Diketopiperazines are reported for the first time from X. fastidiosa , which is responsible for citrus variegated chlorosis. We also report here fatty acids from X. fastidiosa , which were not biologically active as diffusible signals, and the role of diketopiperazines in signal transduction still remains unknown.

  1. The fast breeder reactor

    International Nuclear Information System (INIS)

    Collier, J.

    1990-01-01

    The arguments for and against the fast breeder reactor are debated. The case for the fast reactor is that the world energy demand will increase due to increasing population over the next forty years and that the damage to the global environment from burning fossil fuels which contribute to the greenhouse effect. Nuclear fission is the only large scale energy source which can achieve a cut in the use of carbon based fuels although energy conservation and renewable sources will also be important. Fast reactors produce more energy from uranium than other types of (thermal) reactors such as AGRs and PWRs. Fast reactors would be important from about 2020 onwards especially as by then many thermal reactors will need to be replaced. Fast reactors are also safer than normal reactors. The arguments against fast reactors are largely economic. The cost, especially the capital cost is very high. The viability of the technology is also questioned. (UK)

  2. Fast breeder reactors

    International Nuclear Information System (INIS)

    Heinzel, V.

    1975-01-01

    The author gives a survey of 'fast breeder reactors'. In detail the process of breeding, the reasons for the development of fast breeders, the possible breeder reactors, the design criteria, fuels, cladding, coolant, and safety aspects are reported on. Design data of some experimental reactors already in operation are summarized in stabular form. 300 MWe Prototype-Reactors SNR-300 and PFR are explained in detail and data of KWU helium-cooled fast breeder reactors are given. (HR) [de

  3. Double-differential cross sections for ionization of H2O by fast bare O ions: Comparison with continuum-distorted-wave eikonal-initial-state calculations in prior and post forms

    Science.gov (United States)

    Nandi, S.; Biswas, S.; Khan, A.; Monti, J. M.; Tachino, C. A.; Rivarola, R. D.; Misra, D.; Tribedi, L. C.

    2013-05-01

    We have measured the double-differential cross sections (DDCS) for electron emission in ionization of H2O molecules under the impact of 4.5-MeV/u O8+ ions. The data were collected between 1 and 600 eV, in an angular range of 20∘-150∘ by using an electrostatic hemispherical analyzer. In the experiment we used the H2O vapor in a static gas condition which allowed us to deduce the absolute value of the cross sections. The single-differential cross sections (SDCS) and the total cross sections have also been obtained. The DDCS as well as the SDCS spectra are compared with the continuum-distorted-wave eikonal-initial-state (CDW-EIS) calculations for both the prior as well as the post forms of the scattering matrix. The initial state is represented within the complete neglect of differential overlap approximation, where the molecular orbitals are expressed in terms of atomic orbitals of the atomic constituents. The overall agreement with the CDW-EIS model is quite good as far as the energy dependence is concerned. The prior form of the model is found to provide a better understanding of the data compared to the post version. In particular, excellent agreement between the theory and experiment has been observed for the angular distribution data at forward angles.

  4. Islamic fasting and health.

    Science.gov (United States)

    Azizi, Fereidoun

    2010-01-01

    Muslims fast from sunrise to sunset during the month of Ramadan, the 9th lunar month. The duration of fasting varies from 13 to 18 h/day. Fasting includes avoidance of drinking liquids and eating foods. The aim of this article is to review health-related aspects of Ramadan fasting. Related abstracts from 1960 to 2009 were obtained from Medline and local journals in Islamic countries. One hundred and thirteen articles meeting the criteria for paper selection were reviewed in depth to identify details of related materials. During the fasting days of Ramadan glucose homeostasis is maintained by meals taken before dawn and by liver glycogen stores. Changes in serum lipids are variable and depend on the quality and quantity of food consumption and changes in weight. Compliant, well-controlled type 2 diabetics may observe Ramadan fasting, but fasting is not recommended for type 1, noncompliant, poorly controlled and pregnant diabetics. There are no adverse effects of Ramadan fasting on the heart, lung, liver, kidney, eyes, hematologic profile, endocrine and neuropsychiatric functions. Although Ramadan fasting is safe for all healthy individuals, those with various diseases should consult their physicians and follow scientific recommendations.

  5. Fast Extraction Kicker for the Accelerator Test Facility

    International Nuclear Information System (INIS)

    De Santis, Stefano; Urakawa, Junji; Naito, Takashi

    2007-01-01

    We present the results of a study for the design of a fast extraction kicker to be installed in the Accelerator Test Facility ring at KEK. This activity is carried on in the framework of the ATF2 project, which will be built on the KEK Tsukuba campus as an extension of the existing ATF, taking advantage of the worlds smallest normalized emittance achieved there. ATF2's primary goal is to operate as a test facility and establish the hardware and beam handling technologies envisaged for the International Linear Collider. In particular, the fast extraction kicker object of the present paper is an important component of the ILC damping rings, since its rise and fall time define the minimum distance between bunches and ultimately the damping rings length itself. Building on the initial results presented at EPAC '06, we report on the present status of the kicker design and define the minimum characteristics for pulsers and other subsystems. In addition to the original scheme with multiple stripline modules producing a total deflection of 5 mrad, we also investigated a scheme with a single kicker module for a reduced deflection of 1 mrad placed inside a closed orbit bump, which takes the electron closer to the extraction septum

  6. One-dimensional fossil-like γ-Fe2O3@carbon nanostructure: preparation, structural characterization and application as adsorbent for fast and selective recovery of gold ions from aqueous solution

    Science.gov (United States)

    Gunawan, Poernomo; Xiao, Wen; Hao Chua, Marcus Wen; Poh-Choo Tan, Cheryl; Ding, Jun; Zhong, Ziyi

    2016-10-01

    One-dimensional (1D) magnetic nanostructures with high thermal stability have important industrial applications, but their fabrication remains a big challenge. Herein we demonstrate a scalable approach for the preparation of stable 1D γ-Fe2O3@carbon, which is also applicable for other metal oxide-core and carbon-shell nanostructures, such as 1D TiO2@carbon. One-dimensional ferric oxyhydroxide (α-FeO(OH)) was initially prepared by a hydrothermal method, followed by carbon coating through hydrothermal treatment of the resulting metal oxide in glucose solution. After calcination in N2 gas at 500 °C and subsequent exposure to air, the initial carbon-coated 1D α-Fe2O3 was converted to 1D γ-Fe2O3@carbon, which was very stable without any observed changes even after 1.5 years of storage under ambient conditions. The materials were then used as adsorbents and found to be highly selective towards Au (III) adsorption, of which the maximum adsorption capacity is about 600 mg Au/g sorbent (1132 mg Au/g carbon). The spent sorbent containing Au after adsorption can be readily collected by applying a magnetic field due to the presence of the magnetic core, and the adsorbed Au particles are subsequently recovered after the combustion and dissolution of the sorbent. This work demonstrates not only a facile approach to the fabrication of robust 1D magnetic materials with a stable carbon shell, but also a possible cyanide-free process for the fast and selective recovery of gold from electronic waste and industrial water.

  7. A Synthesis and Crystal Chemical Study of the Fast Ion Conductor Li7–3xGaxLa3 Zr2O12 with x = 0.08 to 0.84

    Science.gov (United States)

    2014-01-01

    Fast-conducting phase-pure cubic Ga-bearing Li7La3Zr2O12 was obtained using solid-state synthesis methods with 0.08 to 0.52 Ga3+ pfu in the garnet. An upper limit of 0.72 Ga3+ pfu in garnet was obtained, but the synthesis was accompanied by small amounts of La2Zr2O12 and LiGaO3. The synthetic products were characterized by X-ray powder diffraction, electron microprobe and SEM analyses, ICP-OES measurements, and 71Ga MAS NMR spectroscopy. The unit-cell parameter, a0, of the various garnets does not vary significantly as a function of Ga3+ content, with a value of about 12.984(4) Å. Full chemical analyses for the solid solutions were obtained giving: Li7.08Ga0.06La2.93Zr2.02O12, Li6.50Ga0.15La2.96Zr2.05O12, Li6.48Ga0.23La2.93Zr2.04O12, Li5.93Ga0.36La2.94Zr2.01O12, Li5.38Ga0.53La2.96Zr1.99O12, Li4.82Ga0.60La2.96Zr2.00O12, and Li4.53Ga0.72La2.94Zr1.98O12. The NMR spectra are interpreted as indicating that Ga3+ mainly occurs in a distorted 4-fold coordinated environment that probably corresponds to the general 96h crystallographic site of garnet. PMID:24874559

  8. Emission characteristics and stability of laser ion sources

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Velyhan, Andriy; Krouský, Eduard; Láska, Leoš; Rohlena, Karel; Jungwirth, Karel; Ullschmied, Jiří; Lorusso, A.; Velardi, L.; Nassisi, V.; Czarnecka, A.; Ryc, L.; Parys, P.; Wolowski, J.

    2010-01-01

    Roč. 85, č. 5 (2010), s. 617-621 ISSN 0042-207X R&D Projects: GA AV ČR IAA100100715 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser ion sources * ion emission reproducibility * thermal and fast ions * ion temperature * centre-of-mass velocity Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.048, year: 2010

  9. Coherent Control of a Single Trapped Rydberg Ion

    Science.gov (United States)

    Higgins, Gerard; Pokorny, Fabian; Zhang, Chi; Bodart, Quentin; Hennrich, Markus

    2017-12-01

    Trapped Rydberg ions are a promising novel approach to quantum computing and simulations. They are envisaged to combine the exquisite control of trapped ion qubits with the fast two-qubit Rydberg gates already demonstrated in neutral atom experiments. Coherent Rydberg excitation is a key requirement for these gates. Here, we carry out the first coherent Rydberg excitation of an ion and perform a single-qubit Rydberg gate, thus demonstrating basic elements of a trapped Rydberg ion quantum computer.

  10. Electrical studies of D%AgI-(100-D)%[0.667Ag2O- 0.333{(0.4)B2O3-(0.6)TeO2}] fast ion conducting glasses

    Science.gov (United States)

    Kumar, E. Ramesh; Nageswar Rao, P.; Appa Rao, B.

    2016-09-01

    Super ion conducting glasses of composition D%AgI-(100-D)%[MAg2O-F{(F1)B2O3- (F2)TeO2}]; D=10.0 to 60.0 in steps of 10.0 for a fixed values of F1 (0.4), F2 (0.6) which are glass network formers, fixed values of modifier M(0.667), F (0.333) and D is dopant salt which was varied. These glasses were prepared by melt quenching technique. XRD spectra taken for all the samples. Electrical characterization was done in terms of AC and DC conductivities. DC and AC conductivities at room temperature increased from 10-5 to 10-1 scm-1 and DC activation energy (Edc) found to decrease from 0.36 to 0.19eV with increase in D% ratio. Measurements are performed over the frequency range 1 kHz to 3 MHz at different temperatures. From the impedance spectroscopy real and imaginary parts of impedances (Z', Z"), conductivities were calculated and plotted, and equivalent R-C circuit parameters were obtained from Cole-Cole plots. With the increase in D%, AC conductivity is observed to increase whereas the AC activation energy (Eac) is observed to decrease from 0.23 to 0.14 eV. The quantitative analysis of these results indicates that the electrical conductivity of silver borate glasses is enhanced with increase in D% ratio. Based on conductivity values these glasses are ionic conductors, in which conduction is by hopping mechanism. An attempt is made to understand the charge transportation process.

  11. Interaction of supra-thermal ions with turbulence in a magnetized toroidal plasma

    International Nuclear Information System (INIS)

    Plyushchev, G.

    2009-01-01

    This thesis addresses the interaction of a supra-thermal ion beam with turbulence in the simple magnetized toroidal plasma of TORPEX. The first part of the Thesis deals with the ohmic assisted discharges on TORPEX. The aim of these discharges is the investigation of the open to closed magnetic field line transition. The relevant magnetic diagnostics were developed. Ohmic assisted discharges with a maximum plasma current up to 1 kA are routinely obtained. The equilibrium conditions on the vacuum magnetic field configuration were investigated. In the second part of the Thesis, the design of the fast ion source and detector are discussed. The accelerating electric field needed for the fast ion source was optimized. The fast ion source was constructed and commissioned. To detect the fast ions a specially designed gridded energy analyzer was used. The electron energy distribution function was obtained to demonstrate the efficiency of the detector. The experiments with the fast ion beam were conducted in different plasma regions of TORPEX. In the third part of the Thesis, numerical simulations are used to interpret the measured fast ion beam behavior. It is shown that a simple single particle equation of motion explains the beam behavior in the experiments in the absence of plasma. To explain the fast ion beam experiments with the plasma a turbulent electric field must be used. The model that takes into account this turbulent electrical field qualitatively explains the shape of the fast ion current density profile in the different plasma regions of TORPEX. The vertically elongated fast ion current density profiles are explained by a spread in the fast ion velocity distribution. The theoretically predicted radial fast ion beam spreading due to the turbulent electric field was observed in the experiment. (author)

  12. Turbulent ion heating in TCV Tokamak plasmas

    International Nuclear Information System (INIS)

    Schlatter, Ch.

    2009-08-01

    The Tokamak à configuration variable (TCV) features the highest electron cyclotron wave power density available to resonantly heat (ECRH) the electrons and to drive noninductive currents in a fusion grade plasma (ECCD). In more than 15 years of exploitation, much effort has been expended on real and velocity space engineering of the plasma electron energy distribution function and thus making electron physics a major research contribution of TCV. When a plasma was first subjected to ECCD, a surprising energisation of the ions, perpendicular to the confining magnetic field, was observed on the charge exchange spectrum measured with the vertical neutral particle analyser (VNPA). It was soon concluded that the ion acceleration was not due to power equipartition between electrons and ions, which, due to the absence of direct ion heating on TCV, has thus far been considered as the only mechanism heating the ions. However, although observed for more than ten years, little attention was paid to this phenomenon, whose cause has remained unexplained to date. The key subject of this thesis is the experimental study of this anomalous ion acceleration, the characterisation in terms of relevant parameters and the presentation of a model simulation of the potential process responsible for the appearance of fast ions. The installation of a new compact neutral particle analyser (CNPA) with an extended high energy range (≥ 50 keV) greatly improved the fast ion properties diagnosis. The CNPA was commissioned and the information derived from its measurement (ion temperature and density, isotopic plasma composition) was validated against other ion diagnostics, namely the active carbon charge exchange recombination spectroscopy system (CXRS) and a neutron counter. In ohmic plasmas, where the ion heating agrees with classical theory, the radial ion temperature profile was successfully reconstructed by vertically displacing the plasma across the horizontal CNPA line of sight. Active

  13. Islamic Fasting and Diabetes

    Directory of Open Access Journals (Sweden)

    Fereidoun Azizi

    2013-07-01

    Full Text Available The aim of this article is to review health-related aspects of Ramadan fasting in normal individuals and diabetics. During fasting days of Ramadan, glucose homeostasis is maintained by meal taken bepore dawn and by liver glycogen stores. Changes in serum lipids are variable and defend on the quality and quantity of food consumption and changes in weight. Compliant, well controlled type 2 diabetics may observe Ramadan fasting; but fasting is not recommended for type 1, non complaint, poorly controlled and pregnant diabetics. Although Ramadan fasting is safe for all healthy individuals and well controlled diabetics, those with uncontrolled diabetics and diabetics with complications should consult physicians and follow scientific recommendations.

  14. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  15. Fast ejendom III

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    Bogen er det tredje bind af tre planlagte bind om fast ejendom: I Overdragelsen, II Bolighandlen og III Ejerbeføjelsen. Fremstillingens giver et grundigt overblik over centrale områder af en omfattende regulering af fast ejendom, med angivelse af litteratur, hvor læseren kan søge yderligere...... oplysning. En ejer af fast ejendom er på særdeles mange områder begrænset i sin råden sammenlignet med ejeren af et formuegode i almindelighed. Fremstillingen tager udgangspunkt i ejerens perspektiv (fremfor samfundets eller myndighedernes). Både den privatretlige og offentligretlige regulering behandles......, eksempelvis ejendomsdannelsen, servitutter, naboretten, hævd, zoneinddelingen, den fysiske planlægning, beskyttelse af natur, beskyttelse af kultur, forurening fra fast ejendom, erstatning for forurening, jordforurening, ekspropriation, byggeri og adgang til fast ejendom....

  16. Phase-space resolved measurement of 2nd harmonic ion cyclotron heating using FIDA tomography at the ASDEX Upgrade tokamak

    DEFF Research Database (Denmark)

    Weiland, M.; Bilato, R.; Geiger, B.

    2017-01-01

    Recent upgrades to the FIDA (fast-ion D-alpha) diagnostic at ASDEX Upgrade allow to reconstruct the fast-ion phase space at several radial positions with decent energy and pitch resolution. These new diagnostic capabilities are applied to study the physics of 2nd harmonic ion cyclotron heating...

  17. Prompt loss of beam ions in KSTAR plasmas

    Directory of Open Access Journals (Sweden)

    Jun Young Kim

    2016-10-01

    Full Text Available For a toroidal plasma facility to realize fusion energy, researching the transport of fast ions is important not only due to its close relation to the heating and current drive efficiencies but also to determine the heat load on the plasma-facing components. We present a theoretical analysis and orbit simulation for the origin of lost fast-ions during neutral beam injection (NBI heating in Korea Superconducting Tokamak Advanced Research (KSTAR device. We adopted a two-dimensional phase diagram of the toroidal momentum and magnetic moment and describe detectable momentums at the fast-ion loss detector (FILD position as a quadratic line. This simple method was used to model birth ions deposited by NBI and drawn as points in the momentum phase space. A Lorentz orbit code was used to calculate the fast-ion orbits and present the prompt loss characteristics of the KSTAR NBI. The scrape-off layer deposition of fast ions produces a significant prompt loss, and the model and experimental results closely agreed on the pitch-angle range of the NBI prompt loss. Our approach can provide wall load information from the fast ion loss.

  18. Centrifugal instability in the regime of fast rotation

    Science.gov (United States)

    Gueroult, R.; Rax, J. M.; Fisch, N. J.

    2017-08-01

    Centrifugal instability, which stems from a difference between the azimuthal angular drift velocity of ions and electrons, is studied in the limit of fast rotation for which ions can rotate up to twice as fast as electrons. As the angular velocity approaches the so-called Brillouin limit, the growth rate for the centrifugal instability in a collisionless solid-body rotating plasma increases markedly and is proportional to the azimuthal mode number. For large wavenumbers, electron inertia effects set in and lead to a cut-off. Interestingly, conditions for the onset of this instability appear to overlap with the operating conditions envisioned for plasma mass separation devices.

  19. Li fast ion conductive La0.56Li0.33TiO3 inlaid LiFePO4/C microspheres with enhanced high-rate performance as cathode materials

    International Nuclear Information System (INIS)

    Shu, Hongbo; Chen, Manfang; Wen, Fang; Fu, Yanqing; Liang, Qianqian; Yang, Xiukang; Shen, Yongqiang; Liu, Li; Wang, Xianyou

    2015-01-01

    the transfer kinetics of both the lithium ions and electrons

  20. ORBIT modelling of fast particle redistribution induced by sawtooth instability

    Science.gov (United States)

    Kim, Doohyun; Podestà, Mario; Poli, Francesca; Princeton Plasma Physics Laboratory Team

    2017-10-01

    Initial tests on NSTX-U show that introducing energy selectivity for sawtooth (ST) induced fast ion redistribution improves the agreement between experimental and simulated quantities, e.g. neutron rate. Thus, it is expected that a proper description of the fast particle redistribution due to ST can improve the modelling of ST instability and interpretation of experiments using a transport code. In this work, we use ORBIT code to characterise the redistribution of fast particles. In order to simulate a ST crash, a spatial and temporal displacement is implemented as ξ (ρ , t , θ , ϕ) = ∑ξmn (ρ , t) cos (mθ + nϕ) to produce perturbed magnetic fields from the equilibrium field B-> , δB-> = ∇ × (ξ-> × B->) , which affect the fast particle distribution. From ORBIT simulations, we find suitable amplitudes of ξ for each ST crash to reproduce the experimental results. The comparison of the simulation and the experimental results will be discussed as well as the dependence of fast ion redistribution on fast ion phase space variables (i.e. energy, magnetic moment and toroidal angular momentum). Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

  1. Structural characterization and complex impedance studies on fast ...

    Indian Academy of Sciences (India)

    Abstract. This paper deals with preparation and physico-chemical characterization of a new mixed system,. (SbI3)x–(Ag2CrO4)1−x (0·1 ≤ x ≤ 0·9), undertaken with a view to evaluate silver ion transport properties and iden- tify those fast ion conducting compositions. Polycrystalline samples of various compositions were ...

  2. Fast track-hoftealloplastik

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Gromov, Kirill; Kristensen, Billy B

    2017-01-01

    Fast-track surgery implies a coordinated perioperative approach aimed at reducing surgical stress and facilitating post-operative recovery. The fast-track programme has reduced post-operative length of stay and has led to shorter convalescence with more rapid functional recovery and decreased...... morbidity and mortality in total hip arthroplasty. It should now be a standard total hip arthroplasty patient pathway, but fine tuning of the multiple factors in the fast-track pathway is still needed in patients with special needs or high comorbidity burden....

  3. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  4. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  5. Fast and pure

    Science.gov (United States)

    De Franceschi, Silvano

    2018-02-01

    Removing nuclear spins by means of isotopically purified silicon, and introducing magnetic field gradients by means of microfabricated ferromagnets yields electron spin qubits with enhanced fidelity and fast electrical control.

  6. Fast neutrons dosimetry

    International Nuclear Information System (INIS)

    Rzyski, B.M.

    1977-01-01

    A proton recoil technique has been developed for inducing thermoluminescence with incident fast neutrons. CaF 2 was used as the TL phosphor, and cane sugar and polyethylene were used as proton radiators. The phosphor and the hydrogeneous material powders were well mixed, encapsulated in glass tubes and exposed to Am-Be sources, resulting in recoils from incident fast neutrons of energy between 0,25 and 11,25 MeV. The intrinsic response of pure CaF 2 to fast neutrons without a hydrogeneous radiator was checked by using LiF (TLD-700). Glow curves were recorded from room temperature up to 350 0 C after different doses of neutrons and gamma rays of 60 Co. First collision dose due to fast neutrons in tissue like materials such as cane sugar and polyethylene was also calculated [pt

  7. Fast Optimal Motion Planning

    Data.gov (United States)

    National Aeronautics and Space Administration — Computationally-efficient, fast and real-time, and provably-optimal motion planner for systems with highly nonlinear dynamics that can be extended for cooperative...

  8. CMS Fast Facts

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS has developed a new quick reference statistical summary on annual CMS program and financial data. CMS Fast Facts includes summary information on total program...

  9. Brug af faste vendinger

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Bjærge, Esben

    Ordbogen indelholder tekstproduktionsangivelser til ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger. Det drejer sig bl.a. om angivelser til betydningen, grammatik, kollokationer, eksempler, synonymer og antonymer.......Ordbogen indelholder tekstproduktionsangivelser til ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger. Det drejer sig bl.a. om angivelser til betydningen, grammatik, kollokationer, eksempler, synonymer og antonymer....

  10. Fast focus field calculations

    OpenAIRE

    Leutenegger, M.; Rao, R.; Leitgeb, R. A.; Lasser, T.

    2006-01-01

    We present a fast calculation of the electromagnetic field near the focus of an objective with a high numerical aperture (NA). Instead of direct integration, the vectorial Debye diffraction integral is evaluated with the fast Fourier transform for calculating the electromagnetic field in the entire focal region. We generalize this concept with the chirp z transform for obtaining a flexible sampling grid and an additional gain in computation speed. Under ...

  11. Fasting and Urinary Stones

    Directory of Open Access Journals (Sweden)

    Ali Shamsa

    2013-11-01

    Full Text Available Introduction: Fasting is considered as one of the most important practices of Islam, and according to Prophet Mohammad, fasting is obligatory upon Muslims. The aim of this study is to evaluate the effects of fasting on urinary stones. Materials and Methods: Very few studies have been carried out on urinary stones and the effect of Ramadan fasting. The sources of the present study are Medline and articles presented by local and Muslim researchers. Meanwhile, since we are acquainted with three well-known researchers in the field of urology, we contacted them via email and asked for their professional opinions. Results: The results of studies about the relationship of urinary stones and their incidence in Ramadan are not alike, and are even sometimes contradictory. Some believe that increased incidence of urinary stones in Ramadan is related not to fasting, but to the rise of weather temperature in hot months, and an increase in humidity. Conclusion: Numerous biological and behavioral changes occur in people who fast in Ramadan and some researchers believe that urinary stone increases during this month.

  12. Ion source

    International Nuclear Information System (INIS)

    1979-01-01

    The ion source comprises a cylindrically shaped chamber with a longitudinal outlet slot formed therein and two uniform anode wires which extend along the length of the chamber in the middle region thereof and which are symmetrically introduced with respect to the length axis of the chamber and the outlet groove, characterised in that at each outer end of the outlet groove at a nearly null potential or direct potential is introduced a mask, whereby the lowest distance between the inner and outer ends of the mask is equivalent to the breadth of the ion beam emitted from the source. (G.C.)

  13. Microsecond pulsed hydrogen/deuterium exchange of electrosprayed ubiquitin ions stored in a linear ion trap.

    Science.gov (United States)

    Rajabi, Khadijeh

    2015-02-07

    A pulse of D2O vapour on the order of microseconds is allowed to react with the +6 to +9 charge states of ubiquitin confined in a linear ion trap (LIT). Two envelopes of peaks are detected for the ions of ubiquitin, corresponding to the ions that exchange more quickly and more slowly. The deuterium uptake of the protonated sites on ubiquitin ions accounts for the ion population with the fast exchange. The hydrogen/deuterium exchange (HDX) kinetics of ubiquitin ions trapped in the LIT for 200 ms showed comparable structural transitions to those trapped for 300 ms. When ions are trapped for longer, i.e. up to 2000 ms, mainly the slow exchanging ion population is detected. In all experiments the +7 ions exchange the most, suggesting a short distance between the surface protonated sites and nearby charged sites, and concomitantly high accessibility of surface protonated sites towards D2O. The +6 ions are more compact than the +7 ions but have one fewer protonated site, therefore fewer surface availabilities for D2O attack. The data suggest that the +6 ions keep most of their solution-phase contacts intact while the hydrophobic core is slightly interrupted in the +7 ions, possibly due to the exposure of charged His68 that is normally buried in the hydrophobic pocket. The +8 and +9 ions have more protonated sites but are less compact than the +7 ions because of Coulombic repulsion, resulting in a larger distance between the protonated sites and the basic sites. The data indicate that the HDX mechanism of ions with the slower exchange corresponding to the second envelope of peaks is primarily governed via a relay mechanism. The results suggest that the pulsed HDX MS method is sampling a population of ubiquitin ions with a similar backbone fold to the solution.

  14. Studies on fast electron transport in the context of fast ignition

    International Nuclear Information System (INIS)

    Batani, D.

    2011-01-01

    This paper deals with the problem of fast electron propagation in plasmas, in the context of the fast ignition (FI) approach to inertial confinement fusion (ICF). In FI, a short-pulse high-intensity laser beam should generate a beam of relativistic electrons, which propagate into the compressed pellet, depositing energy and igniting the fuel. The study of electron propagation in dense matter is hence essential to the success of this scheme. The propagation of relativistic electrons in dense matter is determined by collisions of fast electrons with ions and electrons in the material, which can be described in terms of stopping power, but it also depends on self-generated magnetic and electric fields, which play a major, or even dominant role. In this paper we will show the importance of such collective effects by discussing several experimental examples. (author)

  15. The use and development of ion dispensers for laser-cooled atomic ion experiments

    Science.gov (United States)

    Hucul, David; Christensen, Justin E.; Hudson, Eric R.; Campbell, Wesley C.

    2017-04-01

    Fast, reliable, efficient loading of ions in ion traps is important for laser cooled ion trapping experiments. We utilize a simple surface ionization technique where ions are directly emitted from a platinum surface upon sublimation. This technique of direct ion production has wide applicability to ion trapping experiments and should apply to the direct production of positively charged atomic and molecular species as well as molecular anions. We experimentally demonstrate the ease and flexibility of this technique by directly producing calcium, strontium, cesium, barium, and potassium ions from a heated platinum surface. In addition, this technique is useful for loading rare isotopes into an ion trap. We experimentally demonstrate this by loading large numbers barium ions into an ion trap and distilling rare, isotopically pure ion chains through voltage control and laser heating and cooling. These techniques are directly applicable to the loading of 133Ba+ ions, a candidate qubit that combines the favorable atomic structure of 171Yb+, long-lived metastable states to ensure high fidelity detection, and visible optical transitions to leverage existing optical technologies.

  16. Design and simulation of fast pulsed kicker/bumper units for the positron accumulator ring at APS

    International Nuclear Information System (INIS)

    Wang, Ju; Volk, G.J.

    1991-01-01

    In the design of fast pulsed kicker/burner units for a positron accumulator ring (PAR) at APS, different pulse forming networks (PFN) are considered and different structures for the magnet are studied and simulated. Three fast pulsed kicker/bumper magnets are required in PAR for the beam injection and/or extraction at 450 MeV. These magnets have the same design because they have identical specifications and are expected to produce identical magnetic fields. Each kicker/bumper magnet is required to generate a magnetic field of 0.06 T with rise-time of 80 ns, a flat-top of 80 ns and a fall-time of 80 ns. This paper describes some design considerations and computer simulation results of different designs

  17. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  18. Second-harmonic ion cyclotron resonance heating scenarios of ...

    Indian Academy of Sciences (India)

    Abstract. Plasma heating with the fast magnetosonic waves in the ion cyclotron range of fre- quencies (ICRF) is one of the auxiliary heating schemes of Aditya tokamak. Numerical simulation of second-harmonic resonance heating scenarios in low-temperature, low-density Aditya plasma has been carried out for fast ...

  19. Fast breeder reactors

    International Nuclear Information System (INIS)

    Waltar, A.E.; Reynolds, A.B.

    1981-01-01

    This book describes the major design features of fast breeder reactors and the methods used for their design and analysis. The foremost objective of this book is to fulfill the need for a textbook on Fast Breeder Reactor (FBR) technology at the graduate level or the advanced undergraduate level. It is assumed that the reader has an introductory understanding of reactor theory, heat transfer, and fluid mechanics. The book is expected to be used most widely for a one-semester general course on fast breeder reactors, with the extent of material covered to vary according to the interest of the instructor. The book could also be used effectively for a two-quarter or a two-semester course. In addition, the book could serve as a text for a course on fast reactor safety since many topics other than those appearing in the safety chapters relate to FBR safety. Methodology in fast reactor design and analysis, together with physical descriptions of systems, is emphasized in this text more than numerical results. Analytical and design results continue to change with the ongoing evolution of FBR design whereas many design methods have remained fundamentally unchanged for a considerable time

  20. Fast reactor programme

    International Nuclear Information System (INIS)

    Plakman, J.C.

    1982-01-01

    This progress report summarizes the fast reactor research carried out by ECN during the period covering the year 1980. This research is mainly concerned with the cores of sodium-cooled breeders, in particular the SNR-300, and its related safety aspects. It comprises six items: A programme to determine relevant nuclear data of fission- and corrosion-products; A fuel performance programme comprising in-pile cladding failure experiments and a study of the consequences of loss-of-cooling and overpower; Basic research on fuel; Investigation of the changes in the mechanical properties of austenitic stainless steel DIN 1.4948 due to fast neutron doses, this material has been used in the manufacture of the reactor vessel and its internal components; Study of aerosols which could be formed at the time of a fast reactor accident and their progressive behaviour on leaking through cracks in the concrete containment; Studies on heat transfer in a sodium-cooled fast reactor core. As fast breeders operate at high power densities, an accurate knowledge of the heat transfer phenomena under single-phase and two-phase conditions is sought. (Auth.)

  1. Fast thermal nanoimprint lithography by a stamp with integrated heater

    DEFF Research Database (Denmark)

    Tormen, Massimo; Malureanu, Radu; Pedersen, Rasmus Haugstrup

    2008-01-01

    We propose fast nanoimprinting lithography (NIL) process based on the use of stamps with integrated heater. The latter consists of heavily ion implantation n-type doped silicon layer buried below the microstructured surface of the stamp. The stamp is heated by Joule effect, by 50 μs 25 Hz...

  2. Advances in fast-atom-bombardment mass spectroscopy

    International Nuclear Information System (INIS)

    Hemling, M.E.

    1986-01-01

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

  3. Energy loss of fast H2+ molecules in solids

    International Nuclear Information System (INIS)

    Steinbeck, J.; Dettmann, K.

    1978-01-01

    The electronic energy loss of fast H 2 + ions in thin solids is investigated. The energy loss is influenced by the correlated propagation of the protons which act coherently on the target electrons through a pure Coulomb potential. This influence increases with increasing velocity and decreasing target thickness. The model proposed does not involve the so called 'wake potential'. (author)

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

    Science.gov (United States)

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

    1989-01-01

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

  5. Production of fast neutrons from deuteron beams in view of producing radioactive heavy ions beams; Etude de la production de neutrons rapides a partir de faisceaux de deutons en vue de la mise en oeuvre de faisceaux d'ions lourds radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N

    2000-11-01

    This thesis is part of two research and development programmes for the study of neutron rich radioactive nuclear beam production. The technique is based on the ISOL method and can be summarized as follows. Fast neutrons are generated by the break-up of deuterons in a thick target. These neutrons irradiate a fissionable {sup 238}U target. The resulting fission products are extracted from the target, ionised, mass selected and post-accelerated. The aim of the thesis is to study the neutron angular and energetic distributions. After a bibliographical research to justify the choice of deuterons as the best projectile, we developed more specifically three points: - the extension of the activation detector method for neutron spectroscopy to a wide energy range (1 to 150 MeV), - the experimental measurement of neutron angular and energetic distributions produced by deuterons on thick targets. The deuteron energy ranges from 17 to 200 MeV and the thick targets were Be, C and U, - the realization of a code based on Serber's theory to predict the neutron distribution for any couple (deuteron energy-thick target). We conclude that for our application the most suitable target is C and the best deuteron energy is about 100 MeV. (author)

  6. Design and Testing of a Fast, 50 kV Solid-State Kicker Pulser

    International Nuclear Information System (INIS)

    Cook, E G; Hickman, B C; Lee, B S; Hawkins, S A; Gower, E J; Allen, F V; Walstrom, P L

    2002-01-01

    The ability to extract particle beam bunches from a ring accelerator in arbitrary order can greatly extend an accelerator's capabilities and applications. A prototype solid-state kicker pulser capable of generating asynchronous bursts of 50 kV pulses has been designed and tested into a 50(Omega) load. The pulser features fast rise and fall times and is capable of generating an arbitrary pattern of pulses with a maximum burst frequency exceeding 5 MHz If required, the pulse-width of each pulse in the burst is independently adjustable. This kicker modulator uses multiple solid-state modules stacked in an inductive-adder configuration where the energy is switched into each section of the adder by a parallel array of MOSFETs. Test data, capabilities, and limitations of the prototype pulser are described

  7. Theoretical model of fast electron emission from surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold, C.; Burgdoerfer, J. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Laboratory, TN (United States)

    1993-05-01

    Electron emission in glancing-angle ion-surface collisions has become a focus of ion-surface interactions. Electron spectra can provide detailed information on the above surface neutralization dynamics of multiply charged ions, the electronic structure of the surface (surface density of states), and the long-ranged image interactions near the surface. Recent experiments have found that the convoy peak, well known from ion-atom and ion-solid collisions, is dramatically altered. The peak is broadened and shifted in energy which has been attributed to dynamical image interactions. We present a microscopic model for the emission of fast electrons in glancing-angle surface collisions. A classical trajectory Monte Carlo approach is utilized to calculate the evolution of electrons in the presence of their self image, the projectile Coulomb field and the image potential induced by the projectile. The excitation of collective surface modes is also incorporated.

  8. The fast code

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, L.N.; Wilson, R.E. [Oregon State Univ., Dept. of Mechanical Engineering, Corvallis, OR (United States)

    1996-09-01

    The FAST Code which is capable of determining structural loads on a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees of freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting, occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good. (au)

  9. Adopting preoperative fasting guidelines.

    Science.gov (United States)

    Anderson, Megan; Comrie, Rhonda

    2009-07-01

    In 1999, the American Society of Anesthesiologists adopted preoperative fasting guidelines to enhance the quality and efficiency of patient care. Guidelines suggest that healthy, non-pregnant patients should fast six hours from solids and two hours from liquids. Although these guidelines are in place, studies suggest that providers are still using the blanket statement "NPO after midnight" without regard to patient characteristics, the procedure, or the time of the procedure. Using theory to help change provider's beliefs may help make change more successful. Rogers' Theory of Diffusion of Innovations can assist in changing long-time practice by laying the groundwork for an analysis of the benefits and disadvantages of proposed changes, such as changes to fasting orders, while helping initiate local protocols instead of additional national guidelines.

  10. Ion dynamics in cationic lipid bilayer systems in saline solutions

    DEFF Research Database (Denmark)

    Miettinen, Markus S; Gurtovenko, Andrey A; Vattulainen, Ilpo

    2009-01-01

    at the water-membrane interface to differ qualitatively. Cl(-) ions have well-defined characteristic residence times of nanosecond scale. In contrast, the binding of Na(+) ions to the carbonyl region appears to lack a characteristic time scale, as the residence time distributions displayed power-law features....... As to lateral dynamics, the diffusion of Na(+) ions within the water-membrane interface consists of two qualitatively different modes of motion: very slow diffusion when ions are bound to DMPC, punctuated by fast rapid jumps when detached from the lipids. Overall, the prolonged dynamics of the Na(+) ions...

  11. Some fast beam kicker magnet systems at SLAC

    International Nuclear Information System (INIS)

    Bulos, F.; Cassel, R.L.; Donaldson, A.R.; Genova, L.F.; Grant, J.A.; Mihalka, A.M.; Sukiennicki, B.A.; Tomlin, W.T.; Veldhuizen, F.T.; Walz, D.R.

    1987-01-01

    The Stanford Linear Collider requires very fast rise and fall times from its kicker magnets. The damping rings and positron source need either one or two bunches deflected from two or three that are separated in time by about 59 ns. The final focus region kicker magnets need a rise time of less than 700 ns and each one deflects only one bunch. This paper discusses the design and characteristics of a thyratron-switched, castor-oil-filled, coaxial, Blumlein line used for one bunch kicking. It discharges a 118 ns (at the base), 50 kV, 3 kA pulse into a 33 cm long, ferrite-loaded, kicker magnet of rectangular coaxial-line geometry, which in turn is terminated by a matched load. Reference is made to a Fermilab (FNAL) designed magnet and a dual-thyratron pulser that deflects two serial bunches in or out of the electron ring. Also, a brief description of the final focus magnet is given

  12. Proton Fast Ignition

    International Nuclear Information System (INIS)

    Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

    2006-04-01

    Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

  13. A Fast Hermite Transform.

    Science.gov (United States)

    Leibon, Gregory; Rockmore, Daniel N; Park, Wooram; Taintor, Robert; Chirikjian, Gregory S

    2008-12-17

    We present algorithms for fast and stable approximation of the Hermite transform of a compactly supported function on the real line, attainable via an application of a fast algebraic algorithm for computing sums associated with a three-term relation. Trade-offs between approximation in bandlimit (in the Hermite sense) and size of the support region are addressed. Numerical experiments are presented that show the feasibility and utility of our approach. Generalizations to any family of orthogonal polynomials are outlined. Applications to various problems in tomographic reconstruction, including the determination of protein structure, are discussed.

  14. Fast breeder project (PSB)

    International Nuclear Information System (INIS)

    1976-07-01

    Activities performed during the 1st quarter of 1976 at or on behalf of the Gesellschaft fuer Kernforschung mbH, Karlsruhe, within the framework of the Fast Breeder Project are given a survey. The following project subdivisions are dealt with: Fuel rod development; materials testing and developments; corrosion studies and coolant analyses; physical experiments; reactor theory; safety of fast breeders; instrumentation and signal processing for core monitoring; effects on the environment; sodium technology tests; thermodynamic and fluid flow tests in gas. (HR) [de

  15. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1993-01-01

    Research concentrated on three major areas during the last twelve months: (1) investigations of energy fluence and absorbed dose measurements using crystalline and hot pressed TLD materials exposes to ultrasoft beams of photons, (2) fast neutron kerma factor measurements for several important elements as well as NE-213 scintillation material response function determinations at the intense ''white'' source available at the WNR facility at LAMPF, and (3) kerma factor ratio determinations for carbon and oxygen to A-150 tissue equivalent plastic at the clinical fast neutron radiation facility at Harper Hospital, Detroit, MI. Progress summary reports of these efforts are given in this report

  16. Moms og fast ejendom

    DEFF Research Database (Denmark)

    Edlund, Hans Henrik

    1999-01-01

    I artiklen gives et overblik over, hvorledes fast ejendom behandles momsmæssigt. Derfor findes en kort skitsering af reglerne for moms på byggearbejder, afgrænsningen mellem momspligtig og momsfri udlejning, muligheden for frivillig registrering af udlejning samt opgørelse af reguleringsforpligte......I artiklen gives et overblik over, hvorledes fast ejendom behandles momsmæssigt. Derfor findes en kort skitsering af reglerne for moms på byggearbejder, afgrænsningen mellem momspligtig og momsfri udlejning, muligheden for frivillig registrering af udlejning samt opgørelse af...

  17. Fast ejendom II

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    Fremstillingen påviser, at lov om forbrugerbeskyttelse ved erhvervelse af fast ejendom mv. lider af en række svagheder og at ankenævnspraksis bevæger sig væk fra retspraksis på en række områder.......Fremstillingen påviser, at lov om forbrugerbeskyttelse ved erhvervelse af fast ejendom mv. lider af en række svagheder og at ankenævnspraksis bevæger sig væk fra retspraksis på en række områder....

  18. ION VATAMANU

    Directory of Open Access Journals (Sweden)

    l. Povar

    2012-12-01

    Full Text Available Ion Vatamanu was a chemist, writer and public figure. He was equally passionate about both his chosen fields of activity: chemistry and poetry. Chemistry, with its perfect equilibrium of logic and precision, provided inspiration for lyrical creativity, whereas poetry writing enlivened his imagination and passion for chemistry. He loved his parents. He adored his wife Elena, whom he often gifted a sea of flowers. He loved his daughters Mihaela, Mariana, and Leontina. He loved life, and he loved people.

  19. Ion source

    International Nuclear Information System (INIS)

    Saito, Fusao; Okuyama, Toshihisa; Suzuki, Yasuo.

    1996-01-01

    In a negative ion source having magnetic filters, bisecting magnetic fields are formed using electromagnets disposed at the outside of a plasma source. The position of the electromagnets is made adjustable and removable to optimize a negative ion generation efficiency. Further, a plurality of electromagnets are disposed in longitudinal direction of the plasma source, and the intensity of the magnetic fields of the filters in the longitudinal direction is made adjustable to control a beam distribution. Since uniform magnetic fields which bisect the plasma source can be formed by the electromagnets, and magnetomotive force of the electromagnets can be increased easily compared with that of permanent magnets, the magnetomotive force is changed to obtain appropriate filter magnetic fields easily. Then, optimum magnetic fields corresponding to the state of source plasmas can be generated by the control of the power source of the electromagnets, which also increases the negative ion drawing current density, thereby enabling to reduce the drawing area and size of the plasma source. (N.H.)

  20. Microwave Receivers for Fast-Ion Detection in Fusion Plasmas

    DEFF Research Database (Denmark)

    Furtula, Vedran

    collective Thomson scattering (CTS). The Danish CTS group has been involved in fusion plasma experiments for more than 10 years and the future plans will most probably include the International Thermonuclear Experimental Reactor (ITER). Current CTS systems designed by the Danish group are specified...... are assessed. For the ITER HFS receiver we have designed and measured the quasioptical components that form a transmission link between the plasma and the radio frequency (RF) electronics. This HFS receiver is required to resolve the near parallel velocity components created by the alpha particles. Secondly...... have measured and analyzed all the receiver components starting from the two notch filters to the fifty square-law detector diodes. The receiver sensitivity is calculated from the system measurements and compared with the expected sensitivity based on the individual component measurements. Besides...

  1. Progress on Bayesian Inference of the Fast Ion Distribution Function

    DEFF Research Database (Denmark)

    Stagner, L.; Heidbrink, W.W,; Chen, X.

    2013-01-01

    . However, when theory and experiment disagree (for one or more diagnostics), it is unclear how to proceed. Bayesian statistics provides a framework to infer the DF, quantify errors, and reconcile discrepant diagnostic measurements. Diagnostic errors and weight functions that describe the phase space...... sensitivity of the measurements are incorporated into Bayesian likelihood probabilities. Prior probabilities describe physical constraints. This poster will show reconstructions of classically described, low-power, MHD-quiescent distribution functions from actual FIDA measurements. A description of the full...

  2. Towards Bayesian Inference of the Fast-Ion Distribution Function

    DEFF Research Database (Denmark)

    Stagner, L.; Heidbrink, W.W.; Salewski, Mirko

    2012-01-01

    sensitivity of the measurements are incorporated into Bayesian likelihood probabilities, while prior probabilities enforce physical constraints. As an initial step, this poster uses Bayesian statistics to infer the DIII-D electron density profile from multiple diagnostic measurements. Likelihood functions....... However, when theory and experiment disagree (for one or more diagnostics), it is unclear how to proceed. Bayesian statistics provides a framework to infer the DF, quantify errors, and reconcile discrepant diagnostic measurements. Diagnostic errors and ``weight functions" that describe the phase space...

  3. Ion induced high energy electron emission from copper

    International Nuclear Information System (INIS)

    Ruano, G.; Ferron, J.

    2008-01-01

    We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He + , Ne + and Ar + ) and Li + ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

  4. Neutral Particle Analyzer Measurements of Ion Behavior in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley; R.E. Bell; D.S. Darrow; A.L. Roquemore

    2002-02-06

    Initial results obtained with the Neutral Particle Analyzer (NPA) diagnostic on the National Spherical Torus Experiment (NSTX) are presented. Magnetohydrodynamic activity and reconnection events cause depletion of the deuterium energetic ion distribution created by neutral-beam injection. Adding High Harmonic Fast Wave Heating to neutral-beam-heated discharges results in the generation of an energetic ion tail above the beam injection energy. NPA measurements of the residual hydrogen ion temperature are in good agreement with those from recombination spectroscopy.

  5. Initial use of the positive-ion injector of ATLAS

    International Nuclear Information System (INIS)

    Bollinger, L.M.; Billquist, P.J.; Bogaty, J.M.; Clifft, B.E.; Den Hartog, P.K.; Munson, F.H. Jr.; Pardo, R.C.; Shepard, K.W.; Zinkann, G.P.

    1989-01-01

    The positive-ion injector of ATLAS consists of an ECR heavy-ion source coupled to a 12-MV superconducting injector linac. The ECR source and a 3-MV version of the partially completed linac have been used to accelerate successfully several species of heavy ions. The operating experience is summarized, with emphasis on the excellent beam quality of beams from the new injector. Two new fast-timing detectors are described. 9 refs., 5 figs., 1 tab

  6. Ion Beam Extraction by Discrete Ion Focusing

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (900) and methods are disclosed for ion beam extraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fraction...... of the generated ions. The ion extractor is surrounded by a space charge (810) formed at least in part by the extracted ions. The ion extractor includes a biased electrode (806) forming an interface with an insulator (808). The interface is customized to form a strongly curved potential distribution (812......) in the space-charge surrounding the ion extractor. The strongly curved potential distribution focuses the extracted ions towards an opening (814) on a surface of the biased electrode thereby resulting in an ion beam....

  7. Positive ion irradiation facility

    International Nuclear Information System (INIS)

    Braby, L.A.

    1985-01-01

    Many questions about the mechanisms of the response of cells to ionizing radiation can best be investigated using monoenergetic heavy charged particle beams. Questions of the role of different types of damage in the LET effect, for example, are being answered by comparing repair kinetics for damage induced by electrons with that produced by helium ions. However, as the models become more sophicated, the differences between models can be detected only with more precise measurements, or by combining high- and low-LET irradiations in split-dose experiments. The design of the authors present cell irradiation beam line has limited the authors to irradiating cells in a partial vacuum. A new way to mount the dishes and bring the beam to the cells was required. Several means of irradiating cells in mylar-bottom dishes have been used at other laboratories. For example at the RARAF Facility, the dual ion experiments are done with the dish bottom serving as the beam exit window but the cells are in a partial vacuum to prevent breaking the window. These researchers have chosen instead to use the dish bottom as the beam window and to irradiate the entire dish in a single exposure. A special, very fast pumping system will be installed at the end of the beam line. This system will make it possible to irradiate cells within two minutes of installing them in the irradiation chamber. In this way, the interaction of electron and ion-induced damage in Chlamydomonas can be studied with time between doses as short as 5 minutes

  8. CMS Fast Simulation

    CERN Document Server

    Rahmat, Rahmat

    2012-01-01

    A framework for Fast Simulation of particle interactions in the CMS detector has been developed and implemented in the overall simulation, reconstruction and analysis framework of CMS. It produces data samples in the same format as the one used by the Geant4-based (henceforth Full) Simulation and Reconstruction chain; the output of the Fast Simulation of CMS can therefore be used in the analysis in the same way as other ones. The Fast Simulation has been used already for several physics analyses in CMS, in particular those requiring a generation of many samples to scan an extended parameter space of the physics model (e.g. SUSY). Other use cases dealt with by the Fast Simulation of CMS are those involving the generation of large cross-section backgrounds, and samples of manageable size can only be produced by events skimming based on the final reconstructed objects, or those for which in general a large computation time is foreseen. An important issue, related with the high luminosity achieved by the LHC acce...

  9. FAST compiler user's guide

    NARCIS (Netherlands)

    Hartel, Pieter H.; Glaser, Hugh; Wild, John

    1993-01-01

    The FAST compiler is a backend for compilers of lazy functional languages. There are two versions of the compiler: one that takes a rather simple lazy functional language as input and a second that accepts a language similar to Miranda. On output the compiler produces a set of macro calls that are

  10. Parallel Fast Legendre Transform

    NARCIS (Netherlands)

    Alves de Inda, M.; Bisseling, R.H.; Maslen, D.K.

    1998-01-01

    We discuss a parallel implementation of a fast algorithm for the discrete polynomial Legendre transform We give an introduction to the DriscollHealy algorithm using polynomial arithmetic and present experimental results on the eciency and accuracy of our implementation The algorithms were

  11. ATLAS fast physics monitoring

    Indian Academy of Sciences (India)

    The ATLAS experiment at the Large Hadron Collider is recording data from proton–proton collisions at a centre-of-mass energy of 7 TeV since the spring of 2010. The integrated luminosity has grown nearly exponentially since then and continues to rise fast. The ATLAS Collaboration has set up a framework to automatically ...

  12. ATLAS fast physics monitoring

    Indian Academy of Sciences (India)

    The ATLAS Collaboration has set up a framework to automatically process the rapidly growing dataset and produce performance and physics plots for the most interesting analyses. The system is designed to give fast feedback. The histograms are produced within hours of data reconstruction (2–3 days after data taking).

  13. [Preoperative fasting. An update].

    Science.gov (United States)

    Spies, C D; Breuer, J P; Gust, R; Wichmann, M; Adolph, M; Senkal, M; Kampa, U; Weissauer, W; Schleppers, A; Soreide, E; Martin, E; Kaisers, U; Falke, K J; Haas, N; Kox, W J

    2003-11-01

    In Germany the predominant standard of preoperative care for elective surgery is fasting after midnight, with the aim of reducing the risk of pulmonary aspiration. However, for the past several years the scientific evidence supporting such a practice has been challenged. Experimental and clinical studies prove a reliable gastric emptying within 2 h suggesting that, particularly for limited intake of clear fluids up to 2 h preoperatively, there would be no increased risk for the patient. In addition, the general incidence of pulmonary aspiration during general anaesthesia (before induction, during surgery and during recovery) is extremely low, has a good prognosis and is more a consequence of insufficient airway protection and/or inadequate anaesthetic depth rather than due to the patient's fasting state. Therefore, primarily to decrease perioperative discomfort for patients, several national anaesthesia societies have changed their guidelines for preoperative fasting. They recommend a more liberal policy regarding per os intake of both liquid and solid food, with consideration of certain conditions and contraindications. The following article reviews the literature and gives an overview of the scientific background on which the national guidelines are based. The intention of this review is to propose recommendations for preoperative fasting regarding clear fluids for Germany as well.

  14. Integral Fast Reactor Program

    International Nuclear Information System (INIS)

    Chang, Y.I.; Walters, L.C.; Laidler, J.J.; Pedersen, D.R.; Wade, D.C.; Lineberry, M.J.

    1993-06-01

    This report summarizes highlights of the technical progress made in the Integral Fast Reactor (IFR) Program in FY 1992. Technical accomplishments are presented in the following areas of the IFR technology development activities: (1) metal fuel performance, (2) pyroprocess development, (3) safety experiments and analyses, (4) core design development, (5) fuel cycle demonstration, and (6) LMR technology R ampersand D

  15. Handel med fast ejendom

    DEFF Research Database (Denmark)

    Edlund, Hans Henrik

    Bogen tilstræber at give et overblik over nogle af de vigtigste generelle problemområder på markedet for ejendomshandel, der jo bliver mere og mere kompliceret. Værket er opdelt i følgende hovedafsnit: Ejendomsbegrebet. Indgåelse af aftale om salg af fast ejendom. Begrænsninger i adgangen til...

  16. Fast ejendom, I

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    , værdiforringende forhold, der ligger uden for ejendommen og andre særlige tilfælde. Bogen uddyber andre emner omtalt i 1. udgave, eksempelvis erhvervelsesbetingelser, købsoptioner, ansvarsfraskrivelse, licitationssalg mv. Bogen er det første af tre planlagte bind om fast ejendom: I Overdragelsen, II Bolighandlen...

  17. Fast Harmonic Chirp Summation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom

    2017-01-01

    -robust to noise, or very computationally inten- sive. In this paper, we propose a fast algorithm for the harmonic chirp summation method which has been demonstrated in the liter- ature to be accurate and robust to noise. The proposed algorithm is orders of magnitudes faster than previous algorithms which is also...

  18. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Lineberry, M.J.

    1990-01-01

    Argonne National Laboratory, since 1984, has been developing the Integral Fast Reactor (IFR). This paper will describe the way in which this new reactor concept came about; the technical, public acceptance, and environmental issues that are addressed by the IFR; the technical progress that has been made; and our expectations for this program in the near term. 5 refs., 3 figs

  19. Integral Fast Reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path.

  20. Integral Fast Reactor concept

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path

  1. Calorie count - fast food

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Calorie count - fast food URL of this page: //medlineplus.gov/ency/patientinstructions/ ...

  2. Fast Air Temperature Sensors

    DEFF Research Database (Denmark)

    Hendricks, Elbert

    1998-01-01

    The note documents briefly work done on a newly developed sensor for making fast temperature measurements on the air flow in the intake ports of an SI engine and in the EGR input line. The work reviewed has been carried out in close cooperation with Civ. Ing. Michael Føns, the author (IAU...

  3. Fast Fourier orthogonalization

    NARCIS (Netherlands)

    L. Ducas (Léo); T. Prest; S.A. Abramov; E.V. Zima; X-S. Gao

    2016-01-01

    htmlabstractThe classical fast Fourier transform (FFT) allows to compute in quasi-linear time the product of two polynomials, in the {\\em circular convolution ring} R[x]/(x^d−1) --- a task that naively requires quadratic time. Equivalently, it allows to accelerate matrix-vector products when the

  4. Medical heavy ion accelerator proposals

    International Nuclear Information System (INIS)

    Gough, R.A.

    1985-05-01

    For several decades, accelerators designed primarily for research in nuclear and high energy physics have been adapted for biomedical research including radiotherapeutic treatment of human diseases such as pituitary disorders, cancer, and more recently, arteriovascular malformations. The particles used in these treatments include pions, protons and heavier ions such as carbon, neon, silicon and argon. Maximum beam energies must be available to penetrate into an equivalent of about 30 cm of water, requiring treatment beams of 250 to 1000 MeV/nucleon. Certain special treatments of superficial melanoma, however, require that beam energies as low as 70 MeV/nucleon also be available. Intensities must be adequate to complete a 100 rad treatment fraction in about 1 minute. For most heavy ion treatments, this corresponds to 10 7 -10 9 ions/second at the patient. Because this research is best conducted in a dedicated, hospital-based facility, and because of the clinical need for ultra-high reliability, the construction of new and dedicated facilities has been proposed. Heavy ion accelerators can provide a variety of ions and energies, permitting treatment plans that exploit the properties of the ion best suited to each individual treatment, and that employ radioactive beams (such as 11 C and 19 Ne) to precisely confirm the dose localization. The favored technical approach in these proposals utilizes a conventional, strong-focusing synchrotron capable of fast switching between ions and energies, and servicing multiple treatment rooms. Specialized techniques for shaping the dose to conform to irregularly-shaped target volumes, while simultaneously sparing surrounding, healthy tissue and critical structures, are employed in each treatment room, together with the sophisticated dosimetry necessary for verification, monitoring, and patient safety. 3 refs., 8 figs

  5. Characterization of fast pyrolysis products generated from several western USA woody species

    Science.gov (United States)

    Jacqueline M. Jarvis; Deborah S. Page-Dumroese; Nathaniel M. Anderson; Yuri Corilo; Ryan P. Rodgers

    2014-01-01

    Woody biomass has the potential to be utilized at an alternative fuel source through its pyrolytic conversion. Here, fast pyrolysis bio-oils derived from several western USA woody species are characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to determine molecular-level composition. The...

  6. Sources of polarized negative ions: progress and prospects

    International Nuclear Information System (INIS)

    Haeberli, W.

    1980-01-01

    A summary of recent progress in the art of producing beams of polarized ions is given. In all sources of polarized ions, one first produces (or selects) neutral atoms which are polarized in electron spin. Those types of sources which use a beam of thermal polarized hydrogen atoms are discussed. Progress made in the preparation of the atomic beam and the methods used to convert the neutral atoms to polarized ions is summarized. The second type of source discussed is based on fast (keV) polarized hydrogen atoms. Conversion to negative ions is very simple because one only needs to pass the fast atoms through a suitable charge exchange medium (gas or vapor). However, the production of the polarized atoms is more difficult in this case. The proposal to employ polarized alkali vapor to form a beam of polarized fast H atoms, where the polarized alkali atoms are produced either by an atomic beam apparatus or by optical pumping is discussed

  7. Hemispherical Capsule Implosions for Fast Ignition*

    Science.gov (United States)

    Hanson, D. L.; Vesey, R. A.; Sinars, D. B.; Adams, R. G.; Cuneo, M. E.; Porter, J. L.; Slutz, S. A.; Johnston, R. R.; Wenger, D. F.; Schroen, D. G.

    2003-10-01

    The fast ignitor approach to ICF ignition separates the fuel assembly and fast heating processes. After compressing the fuel with the main driver, the fuel is ignited using a focused electron or ion beam generated by a fast, ultra-high power laser pulse. This significantly relaxes the drive symmetry, energy, and shock timing requirements compared to hot spot ignition. A hemispherical capsule target is a fast ignitor geometry well-adapted to symmetric fuel compression by a single-ended z-pinch radiation drive. The hemispherical capsule implodes radially, constrained at its equator by a flat high-density surface (a special case of the spherical capsule "cone-focus" geometry). This glide plane is mounted on a hollow pedestal that provides a plasma-free, short-pulse laser path to the compressed fuel core region. In experiments on the Z accelerator at Sandia, we are studying implosions of 2.0-mm-diameter, 60-micron-thick hemispherical capsules in cylindrical secondary hohlraums heated to 90-100 eV from one end by a 120 TW wire-array z-pinch. Analysis of ZBL 6.7 keV point-projection backlighter images of pole-hot implosions in a tall secondary and 6.18 keV monochromatic crystal backlighter images of more symmetric implosions in a short secondary will be presented. We will also discuss progress on the development of a cryogenic liquid fuel target for this fast ignitor compression geometry. * Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  8. Fast Molecular Cloud Destruction Requires Fast Cloud Formation

    Energy Technology Data Exchange (ETDEWEB)

    Mac Low, Mordecai-Mark [American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States); Burkert, Andreas [Universitäts Sternwarte München, Ludwigs-Maximilian-Universität, D-81679 München (Germany); Ibáñez-Mejía, Juan C., E-mail: mordecai@amnh.org, E-mail: burkert@usm.lmu.de, E-mail: ibanez@ph1.uni-koeln.de [Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching bei München (Germany)

    2017-09-20

    A large fraction of the gas in the Galaxy is cold, dense, and molecular. If all this gas collapsed under the influence of gravity and formed stars in a local free-fall time, the star formation rate in the Galaxy would exceed that observed by more than an order of magnitude. Other star-forming galaxies behave similarly. Yet, observations and simulations both suggest that the molecular gas is indeed gravitationally collapsing, albeit hierarchically. Prompt stellar feedback offers a potential solution to the low observed star formation rate if it quickly disrupts star-forming clouds during gravitational collapse. However, this requires that molecular clouds must be short-lived objects, raising the question of how so much gas can be observed in the molecular phase. This can occur only if molecular clouds form as quickly as they are destroyed, maintaining a global equilibrium fraction of dense gas. We therefore examine cloud formation timescales. We first demonstrate that supernova and superbubble sweeping cannot produce dense gas at the rate required to match the cloud destruction rate. On the other hand, Toomre gravitational instability can reach the required production rate. We thus argue that, although dense, star-forming gas may last only around a single global free-fall time; the dense gas in star-forming galaxies can globally exist in a state of dynamic equilibrium between formation by gravitational instability and disruption by stellar feedback. At redshift z ≳ 2, the Toomre instability timescale decreases, resulting in a prediction of higher molecular gas fractions at early times, in agreement with the observations.

  9. Heavy ions

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  10. Heavy ions

    CERN Multimedia

    CERN. Geneva; Antinori, Federico

    2001-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  11. ION GUN

    Science.gov (United States)

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  12. Fast timing discriminator

    International Nuclear Information System (INIS)

    Lo, C.C.

    1977-01-01

    The processing of pulses with very fast risetimes for timing purposes involves many problems because of the large equivalent bandwidths involved. For pulses with risetimes in the 150 ps range (and full widths at half maximum (FWHM) of 400 ps) bandwidths in excess of 1GHz are required. Furthermore, these very narrow pulses with current amplitudes as small as 1 mA carry very small charges ( -12 coulomb), therefore, requiring very sensitive trigger circuits. The difficulty increases when timing characteristics in the picosecond range are sought especially when a wide input signal amplitude range causes a time-walk problem. The fast timing discriminator described has a time-walk of approximately +-75 ps over the input signal range from 80 mV to 3V. A schematic of the discriminator is included, and operation and performance are discussed

  13. Fast radiographic systems

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1984-08-01

    Industrial radiography can be performed with shorter exposure times, when instead of X-ray film with lead intensifying screens the radiographic paper with fluorescent screen is used. With paper radiography one can obtain lower material, equipment, and labor costs, shorter exposure and processing times, and easier radiation protection. The speed of the radiographic inspection can also be increased by the use of fluorometallic intensifying screens together with a special brand of X-ray film. Before accepting either of the two fast radiographic systems one must be sure that they can produce radiographs of adequate image quality. Therefore an investigation was performed on that subject using ISO wire IQI's and ASTM penetrameters. The radiographic image quality was tested for aluminium and steel up to 30 mm thick using various brands of radiographic paper and X-ray film with fluorometallic screens and comparing them with fast X-ray films with lead screens. Both systems give satisfactory results. (author)

  14. PHENIX Fast TOF

    Energy Technology Data Exchange (ETDEWEB)

    Soha, Aria [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chiu, Mickey [Brookhaven National Lab. (BNL), Upton, NY (United States); Mannel, Eric [Brookhaven National Lab. (BNL), Upton, NY (United States); Stoll, Sean [Brookhaven National Lab. (BNL), Upton, NY (United States); Lynch, Don [Brookhaven National Lab. (BNL), Upton, NY (United States); Boose, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States); Northacker, Dave [Brookhaven National Lab. (BNL), Upton, NY (United States); Alfred, Marcus [Howard Univ., Washington, DC (United States); Lindesay, James [Howard Univ., Washington, DC (United States); Chujo, Tatsuya [Univ. of Tsukuba (Japan); Inaba, Motoi [Univ. of Tsukuba (Japan); Nonaka, Toshihiro [Univ. of Tsukuba (Japan); Sato, Wataru [Univ. of Tsukuba (Japan); Sakatani, Ikumi [Univ. of Tsukuba (Japan); Hirano, Masahiro [Univ. of Tsukuba (Japan); Choi, Ihnjea [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2014-01-15

    This is a technical scope of work (TSW) between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of PHENIX Fast TOF group who have committed to participate in beam tests to be carried out during the FY2014 Fermilab Test Beam Facility program. The goals for this test beam experiment are to verify the timing performance of the two types of time-of-flight detector prototypes.

  15. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    Chang, Y.I.

    1988-01-01

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics. 3 refs., 4 figs., 1 tab

  16. Generalized rate-equation analysis of excitation exchange between silicon nanoclusters and erbium ions

    International Nuclear Information System (INIS)

    Kenyon, A. J.; Wojdak, M.; Ahmad, I.; Loh, W. H.; Oton, C. J.

    2008-01-01

    We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters

  17. Fast Light Optical Gyroscopes

    Science.gov (United States)

    Smith, David D.

    2015-01-01

    Next-generation space missions are currently constrained by existing spacecraft navigation systems which are not fully autonomous. These systems suffer from accumulated dead-reckoning errors and must therefore rely on periodic corrections provided by supplementary technologies that depend on line-of-sight signals from Earth, satellites, or other celestial bodies for absolute attitude and position determination, which can be spoofed, incorrectly identified, occluded, obscured, attenuated, or insufficiently available. These dead-reckoning errors originate in the ring laser gyros themselves, which constitute inertial measurement units. Increasing the time for standalone spacecraft navigation therefore requires fundamental improvements in gyroscope technologies. One promising solution to enhance gyro sensitivity is to place an anomalous dispersion or fast light material inside the gyro cavity. The fast light essentially provides a positive feedback to the gyro response, resulting in a larger measured beat frequency for a given rotation rate as shown in figure 1. Game Changing Development has been investing in this idea through the Fast Light Optical Gyros (FLOG) project, a collaborative effort which began in FY 2013 between NASA Marshall Space Flight Center (MSFC), the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), and Northwestern University. MSFC and AMRDEC are working on the development of a passive FLOG (PFLOG), while Northwestern is developing an active FLOG (AFLOG). The project has demonstrated new benchmarks in the state of the art for scale factor sensitivity enhancement. Recent results show cavity scale factor enhancements of approx.100 for passive cavities.

  18. ADT fast losses MD

    CERN Document Server

    Priebe, A; Dehning, B; Redaelli, S; Salvachua Ferrando, BM; Sapinski, M; Solfaroli Camillocci, M; Valuch, D

    2013-01-01

    The fast beam losses in the order of 1 ms are expected to be a potential major luminosity limitation for higher beam energies after the LHC long shutdown (LS1). Therefore a Quench Test is planned in the winter 2013 to estimate the quench limit in this timescale and revise the current models. This experiment was devoted to determination the LHC Transverse Damper (ADT) as a system for fast losses induction. A non-standard operation of the ADT was used to develop the beam oscillation instead of suppressing them. The sign flip method had allowed us to create the fast losses within several LHC turns at 450 GeV during the previous test (26th March 2012). Thus, the ADT could be potentially used for the studies of the UFO ("Unidentied Falling Object") impact on the cold magnets. Verification of the system capability and investigations of the disturbed beam properties were the main objectives of this MD. During the experiment, the pilot bunches of proton beam were excited independently in the horizontal and vertical ...

  19. Metabolic Effects of Intermittent Fasting.

    Science.gov (United States)

    Patterson, Ruth E; Sears, Dorothy D

    2017-08-21

    The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

  20. Neighborhood fast food availability and fast food consumption

    Science.gov (United States)

    Oexle, Nathalie; Barnes, Timothy L; Blake, Christine E; Bell, Bethany A; Liese, Angela D

    2015-01-01

    Recent nutritional and public health research has focused on how the availability of various types of food in a person’s immediate area or neighborhood influences his or her food choices and eating habits. It has been theorized that people living in areas with a wealth of unhealthy fast-food options may show higher levels of fast-food consumption, a factor that often coincides with being overweight or obese. However, measuring food availability in a particular area is difficult to achieve consistently: there may be differences in the strict physical locations of food options as compared to how individuals perceive their personal food availability, and various studies may use either one or both of these measures. The aim of this study was to evaluate the association between weekly fast-food consumption and both a person’s perceived availability of fast-food and an objective measure of fast-food presence—Geographic Information Systems (GIS)—within that person’s neighborhood. A randomly selected population-based sample of eight counties in South Carolina was used to conduct a cross-sectional telephone survey assessing self-report fast-food consumption and perceived availability of fast food. GIS was used to determine the actual number of fast-food outlets within each participant’s neighborhood. Using multinomial logistic regression analyses, we found that neither perceived availability nor GIS-based presence of fast-food was significantly associated with weekly fast-food consumption. Our findings indicate that availability might not be the dominant factor influencing fast-food consumption. We recommend using subjective availability measures and considering individual characteristics that could influence both perceived availability of fast food and its impact on fast-food consumption. If replicated, our findings suggest that interventions aimed at reducing fast-food consumption by limiting neighborhood fast-food availability might not be completely