WorldWideScience

Sample records for single ion models

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

    International Nuclear Information System (INIS)

    Liu Lei; Yan Shilei

    2005-01-01

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

  2. A generalized Jaynes-Cummings model: The relativistic parametric amplifier and a single trapped ion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-Guillén, D., E-mail: dojedag@ipn.mx [Escuela Superior de Cómputo, Instituto Politécnico Nacional, Av. Juan de Dios Bátiz esq. Av. Miguel Othón de Mendizábal, Col. Lindavista, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico); Mota, R. D. [Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana No. 1000, Col. San Francisco Culhuacán, Delegación Coyoacán, C.P. 04430 Ciudad de México (Mexico); Granados, V. D. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ed. 9, Unidad Profesional Adolfo López Mateos, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico)

    2016-06-15

    We introduce a generalization of the Jaynes-Cummings model and study some of its properties. We obtain the energy spectrum and eigenfunctions of this model by using the tilting transformation and the squeezed number states of the one-dimensional harmonic oscillator. As physical applications, we connect this new model to two important and novelty problems: the relativistic parametric amplifier and the quantum simulation of a single trapped ion.

  3. Fully differential cross sections for the single ionization of helium by fast ions: Classical model calculations

    Science.gov (United States)

    Sarkadi, L.

    2018-04-01

    Fully differential cross sections (FDCSs) have been calculated for the single ionization of helium by 1- and 3-MeV proton and 100-MeV/u C6 + ion impact using the classical trajectory Monte Carlo (CTMC) method in the nonrelativistic, three-body approximation. The calculations were made employing a Wigner-type model in which the quantum-mechanical position distribution of the electron is approximated by a weighted integral of the microcanonical distribution over a range of the binding energy of the electron. In the scattering plane, the model satisfactorily reproduces the observed shape of the binary peak. In the region of the peak the calculated FDCSs agree well with the results of continuum-distorted-wave calculations for all the investigated collisions. For 1-MeV proton impact the experimentally observed shift of the binary peak with respect to the first Born approximation is compared with the shifts obtained by different higher-order quantum-mechanical theories and the present CTMC method. The best result was achieved by CTMC, but still a large part of the shift remained unexplained. Furthermore, it was found that the classical theory failed to reproduce the shape of the recoil peak observed in the experiments, it predicts a much narrower peak. This indicates that the formation of the recoil peak is dominated by quantum-mechanical effects. For 100-MeV/u C6 + ion impact the present CTMC calculations confirmed the existence of the "double-peak" structure of the angular distribution of the electron in the plane perpendicular to the momentum transfer, in accordance with the observation, the prediction of an incoherent semiclassical model, and previous CTMC results. This finding together with wave-packet calculations suggests that the "C6 + puzzle" may be solved by considering the loss of the projectile coherence. Experiments to be conducted using ion beams of anisotropic coherence are proposed for a more differential investigation of the ionization dynamics.

  4. Single Cathode Ion Thruster

    Data.gov (United States)

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

  5. CDW-EIS model for single-electron capture in ion-atom collisions involving multielectronic targets

    International Nuclear Information System (INIS)

    Abufager, P N; MartInez, A E; Rivarola, R D; Fainstein, P D

    2004-01-01

    A generalization of the continuum distorted wave eikonal initial state (CDW-EIS) approximation, for the description of single-electron capture in ion-atom collisions involving multielectronic targets is presented. This approximation is developed within the framework of the independent electron model taking particular care of the representation of the bound and continuum target states. Total cross sections for single-electron capture from the K-shell of He, Ne and Ar noble gases by impact of bare ions are calculated. Present results are compared to previous CDW-EIS ones and to experimental data

  6. Fatigue in isometric contraction in a single muscle fibre: a compartmental calcium ion flow model.

    Science.gov (United States)

    Kothiyal, K P; Ibramsha, M

    1986-01-01

    Fatigue in muscle is a complex biological phenomenon which has so far eluded a definite explanation. Many biochemical and physiological models have been suggested in the literature to account for the decrement in the ability of muscle to sustain a given level of force for a long time. Some of these models have been critically analysed in this paper and are shown to be not able to explain all the experimental observations. A new compartmental model based on the intracellular calcium ion movement in muscle is proposed to study the mechanical responses of a muscle fibre. Computer simulation is performed to obtain model responses in isometric contraction to an impulse and a train of stimuli of long duration. The simulated curves have been compared with experimentally observed mechanical responses of the semitendinosus muscle fibre of Rana pipiens. The comparison of computed and observed responses indicates that the proposed calcium ion model indeed accounts very well for the muscle fatigue.

  7. A permeation theory for single-file ion channels: one- and two-step models.

    Science.gov (United States)

    Nelson, Peter Hugo

    2011-04-28

    How many steps are required to model permeation through ion channels? This question is investigated by comparing one- and two-step models of permeation with experiment and MD simulation for the first time. In recent MD simulations, the observed permeation mechanism was identified as resembling a Hodgkin and Keynes knock-on mechanism with one voltage-dependent rate-determining step [Jensen et al., PNAS 107, 5833 (2010)]. These previously published simulation data are fitted to a one-step knock-on model that successfully explains the highly non-Ohmic current-voltage curve observed in the simulation. However, these predictions (and the simulations upon which they are based) are not representative of real channel behavior, which is typically Ohmic at low voltages. A two-step association/dissociation (A/D) model is then compared with experiment for the first time. This two-parameter model is shown to be remarkably consistent with previously published permeation experiments through the MaxiK potassium channel over a wide range of concentrations and positive voltages. The A/D model also provides a first-order explanation of permeation through the Shaker potassium channel, but it does not explain the asymmetry observed experimentally. To address this, a new asymmetric variant of the A/D model is developed using the present theoretical framework. It includes a third parameter that represents the value of the "permeation coordinate" (fractional electric potential energy) corresponding to the triply occupied state n of the channel. This asymmetric A/D model is fitted to published permeation data through the Shaker potassium channel at physiological concentrations, and it successfully predicts qualitative changes in the negative current-voltage data (including a transition to super-Ohmic behavior) based solely on a fit to positive-voltage data (that appear linear). The A/D model appears to be qualitatively consistent with a large group of published MD simulations, but no

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

    CERN Document Server

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

    2011-01-01

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

  9. Stochastic modelling of a single ion channel: an alternating renewal approach with application to limited time resolution.

    Science.gov (United States)

    Milne, R K; Yeo, G F; Edeson, R O; Madsen, B W

    1988-04-22

    Stochastic models of ion channels have been based largely on Markov theory where individual states and transition rates must be specified, and sojourn-time densities for each state are constrained to be exponential. This study presents an approach based on random-sum methods and alternating-renewal theory, allowing individual states to be grouped into classes provided the successive sojourn times in a given class are independent and identically distributed. Under these conditions Markov models form a special case. The utility of the approach is illustrated by considering the effects of limited time resolution (modelled by using a discrete detection limit, xi) on the properties of observable events, with emphasis on the observed open-time (xi-open-time). The cumulants and Laplace transform for a xi-open-time are derived for a range of Markov and non-Markov models; several useful approximations to the xi-open-time density function are presented. Numerical studies show that the effects of limited time resolution can be extreme, and also highlight the relative importance of the various model parameters. The theory could form a basis for future inferential studies in which parameter estimation takes account of limited time resolution in single channel records. Appendixes include relevant results concerning random sums and a discussion of the role of exponential distributions in Markov models.

  10. Single-ion nonlinear mechanical oscillator

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  11. Development of single cell lithium ion battery model using Scilab/Xcos

    Science.gov (United States)

    Arianto, Sigit; Yunaningsih, Rietje Y.; Astuti, Edi Tri; Hafiz, Samsul

    2016-02-01

    In this research, a lithium battery model, as a component in a simulation environment, was developed and implemented using Scicos/Xcos graphical language programming. Scicos used in this research was actually Xcos that is a variant of Scicos which is embedded in Scilab. The equivalent circuit model used in modeling the battery was Double Polarization (DP) model. DP model consists of one open circuit voltage (VOC), one internal resistance (Ri), and two parallel RC circuits. The parameters of the battery were extracted using Hybrid Power Pulse Characterization (HPPC) testing. In this experiment, the Double Polarization (DP) electrical circuit model was used to describe the lithium battery dynamic behavior. The results of simulation of the model were validated with the experimental results. Using simple error analysis, it was found out that the biggest error was 0.275 Volt. It was occurred mostly at the low end of the state of charge (SOC).

  12. Poisson-Fermi modeling of ion activities in aqueous single and mixed electrolyte solutions at variable temperature

    Science.gov (United States)

    Liu, Jinn-Liang; Eisenberg, Bob

    2018-02-01

    The combinatorial explosion of empirical parameters in tens of thousands presents a tremendous challenge for extended Debye-Hückel models to calculate activity coefficients of aqueous mixtures of the most important salts in chemistry. The explosion of parameters originates from the phenomenological extension of the Debye-Hückel theory that does not take steric and correlation effects of ions and water into account. By contrast, the Poisson-Fermi theory developed in recent years treats ions and water molecules as nonuniform hard spheres of any size with interstitial voids and includes ion-water and ion-ion correlations. We present a Poisson-Fermi model and numerical methods for calculating the individual or mean activity coefficient of electrolyte solutions with any arbitrary number of ionic species in a large range of salt concentrations and temperatures. For each activity-concentration curve, we show that the Poisson-Fermi model requires only three unchanging parameters at most to well fit the corresponding experimental data. The three parameters are associated with the Born radius of the solvation energy of an ion in electrolyte solution that changes with salt concentrations in a highly nonlinear manner.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  14. Ion thruster performance model

    International Nuclear Information System (INIS)

    Brophy, J.R.

    1984-01-01

    A model of ion thruster performance is developed for high flux density cusped magnetic field thruster designs. This model is formulated in terms of the average energy required to produce an ion in the discharge chamber plasma and the fraction of these ions that are extracted to form the beam. The direct loss of high energy (primary) electrons from the plasma to the anode is shown to have a major effect on thruster performance. The model provides simple algebraic equations enabling one to calculate the beam ion energy cost, the average discharge chamber plasma ion energy cost, the primary electron density, the primary-to-Maxwellian electron density ratio and the Maxwellian electron temperature. Experiments indicate that the model correctly predicts the variation in plasma ion energy cost for changes in propellant gas (Ar, Kr, and Xe), grid transparency to neutral atoms, beam extraction area, discharge voltage, and discharge chamber wall temperature

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-28

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

  16. Improved single ion cyclotron resonance mass spectroscopy

    International Nuclear Information System (INIS)

    Boyce, K.R.

    1993-01-01

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

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

    Science.gov (United States)

    Zelenak, A.; Bogomolov, S. L.

    2004-05-01

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

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

    International Nuclear Information System (INIS)

    Zelenak, A.; Bogomolov, S.L.

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    DEFF Research Database (Denmark)

    Legrand, Olivier Philippe Alexandre

    2015-01-01

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

  1. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    International Nuclear Information System (INIS)

    Nyiri, Agnes

    2005-01-01

    The goal of this PhD project was to develop the already existing, but far not complete Multi Module Model, specially focusing on the last module which describes the final stages of a heavy ion collision, as this module was still missing. The major original achievements summarized in this thesis correspond to the freeze out problem and calculation of an important measurable, the anisotropic flow. Summary of results: Freeze out: The importance of freeze out models is that they allow the evaluation of observables, which then can be compared to the experimental results. Therefore, it is crucial to find a realistic freeze out description, which is proved to be a non-trivial task. Recently, several kinetic freeze out models have been developed. Based on the earlier results, we have introduced new ideas and improved models, which may contribute to a more realistic description of the freeze out process. We have investigated the applicability of the Boltzmann Transport Equation (BTE) to describe dynamical freeze out. We have introduced the so-called Modified Boltzmann Transport Equation, which has a form very similar to that of the BTE, but takes into account those characteristics of the FO process which the BTE can not handle, e.g. the rapid change of the phase-space distribution function in the direction normal to the finite FO layer. We have shown that the main features of earlier ad hoc kinetic FO models can be obtained from BTE and MBTE. We have discussed the qualitative differences between the two approaches and presented some quantitative comparison as well. Since the introduced modification of the BTE makes it very difficult to solve the FO problem from the first principles, it is important to work out simplified phenomenological models, which can explain the basic features of the FO process. We have built and discussed such a model. Flow analysis: The other main subject of this thesis has been the collective flow in heavy ion collisions. Collective flow from ultra

  2. Development of pulsation technique for single ion hit system

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

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

    International Nuclear Information System (INIS)

    Maniscalco, S

    2005-01-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

  5. Multiple Quantum Coherences (MQ) NMR and Entanglement Dynamics in the Mixed-Three-Spin XXX Heisenberg Model with Single-Ion Anisotropy

    Science.gov (United States)

    Hamid, Arian Zad

    2016-12-01

    We analytically investigate Multiple Quantum (MQ) NMR dynamics in a mixed-three-spin (1/2,1,1/2) system with XXX Heisenberg model at the front of an external homogeneous magnetic field B. A single-ion anisotropy property ζ is considered for the spin-1. The intensities dependence of MQ NMR coherences on their orders (zeroth and second orders) for two pairs of spins (1,1/2) and (1/2,1/2) of the favorite tripartite system are obtained. It is also investigated dynamics of the pairwise quantum entanglement for the bipartite (sub)systems (1,1/2) and (1/2,1/2) permanently coupled by, respectively, coupling constants J}1 and J}2, by means of concurrence and fidelity. Then, some straightforward comparisons are done between these quantities and the intensities of MQ NMR coherences and ultimately some interesting results are reported. We also show that the time evolution of MQ coherences based on the reduced density matrix of the pair spins (1,1/2) is closely connected with the dynamics of the pairwise entanglement. Finally, we prove that one can introduce MQ coherence of the zeroth order corresponds to the pair spins (1,1/2) as an entanglement witness at some special time intervals.

  6. The field-induced laws of thermodynamic properties in the two-dimensional spin-1 ferromagnetic Heisenberg model with the exchange and single-ion anisotropies

    International Nuclear Information System (INIS)

    Pu Qiurong; Chen Yuan

    2013-01-01

    Green's function method is applied to investigate the two-dimensional spin-1 ferromagnetic Heisenberg model with the exchange and single-ion anisotropies. In the presence of the magnetic field, the effects of the anisotropies and field on the thermodynamic properties are obtained within the random phase approximation combining with Anderson-Callen approximation. The field-induced laws are found for the thermodynamic properties. Field dependences of heights of the susceptibility maximum and specific heat maximum fit well to power laws. The linear increase at high fields is shown for positions of the susceptibility maximum and specific heat maximum. A power law at low fields occurs for the position of the susceptibility maximum. At the positions of the maxima, the magnetization and internal energy display the power-law increase and linear decrease with the field, respectively. The exponents of the power laws are dependent of the anisotropies, as well as the slopes of the linear laws. Our results do not support the 2/3 power law which was obtained by the Landau theory.

  7. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    Energy Technology Data Exchange (ETDEWEB)

    Nyiri, Agnes

    2005-07-01

    The goal of this PhD project was to develop the already existing, but far not complete Multi Module Model, specially focusing on the last module which describes the final stages of a heavy ion collision, as this module was still missing. The major original achievements summarized in this thesis correspond to the freeze out problem and calculation of an important measurable, the anisotropic flow. Summary of results: Freeze out: The importance of freeze out models is that they allow the evaluation of observables, which then can be compared to the experimental results. Therefore, it is crucial to find a realistic freeze out description, which is proved to be a non-trivial task. Recently, several kinetic freeze out models have been developed. Based on the earlier results, we have introduced new ideas and improved models, which may contribute to a more realistic description of the freeze out process. We have investigated the applicability of the Boltzmann Transport Equation (BTE) to describe dynamical freeze out. We have introduced the so-called Modified Boltzmann Transport Equation, which has a form very similar to that of the BTE, but takes into account those characteristics of the FO process which the BTE can not handle, e.g. the rapid change of the phase-space distribution function in the direction normal to the finite FO layer. We have shown that the main features of earlier ad hoc kinetic FO models can be obtained from BTE and MBTE. We have discussed the qualitative differences between the two approaches and presented some quantitative comparison as well. Since the introduced modification of the BTE makes it very difficult to solve the FO problem from the first principles, it is important to work out simplified phenomenological models, which can explain the basic features of the FO process. We have built and discussed such a model. Flow analysis: The other main subject of this thesis has been the collective flow in heavy ion collisions. Collective flow from ultra

  8. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    Energy Technology Data Exchange (ETDEWEB)

    Nyiri, Agnes

    2005-07-01

    The goal of this PhD project was to develop the already existing, but far not complete Multi Module Model, specially focusing on the last module which describes the final stages of a heavy ion collision, as this module was still missing. The major original achievements summarized in this thesis correspond to the freeze out problem and calculation of an important measurable, the anisotropic flow. Summary of results: Freeze out: The importance of freeze out models is that they allow the evaluation of observables, which then can be compared to the experimental results. Therefore, it is crucial to find a realistic freeze out description, which is proved to be a non-trivial task. Recently, several kinetic freeze out models have been developed. Based on the earlier results, we have introduced new ideas and improved models, which may contribute to a more realistic description of the freeze out process. We have investigated the applicability of the Boltzmann Transport Equation (BTE) to describe dynamical freeze out. We have introduced the so-called Modified Boltzmann Transport Equation, which has a form very similar to that of the BTE, but takes into account those characteristics of the FO process which the BTE can not handle, e.g. the rapid change of the phase-space distribution function in the direction normal to the finite FO layer. We have shown that the main features of earlier ad hoc kinetic FO models can be obtained from BTE and MBTE. We have discussed the qualitative differences between the two approaches and presented some quantitative comparison as well. Since the introduced modification of the BTE makes it very difficult to solve the FO problem from the first principles, it is important to work out simplified phenomenological models, which can explain the basic features of the FO process. We have built and discussed such a model. Flow analysis: The other main subject of this thesis has been the collective flow in heavy ion collisions. Collective flow from ultra

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-13

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

  11. Ion implantation of CdTe single crystals

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  13. Plastic flow produced by single ion impacts on metals

    International Nuclear Information System (INIS)

    Birtcher, R. C.

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  16. Probing Surface Electric Field Noise with a Single Ion

    Science.gov (United States)

    2013-07-30

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

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

    Science.gov (United States)

    Morris, Melody; Epps, Thomas H., III

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

  18. Numerical modelling of ion transport in flames

    KAUST Repository

    Han, Jie

    2015-10-20

    This paper presents a modelling framework to compute the diffusivity and mobility of ions in flames. The (n, 6, 4) interaction potential is adopted to model collisions between neutral and charged species. All required parameters in the potential are related to the polarizability of the species pair via semi-empirical formulas, which are derived using the most recently published data or best estimates. The resulting framework permits computation of the transport coefficients of any ion found in a hydrocarbon flame. The accuracy of the proposed method is evaluated by comparing its predictions with experimental data on the mobility of selected ions in single-component neutral gases. Based on this analysis, the value of a model constant available in the literature is modified in order to improve the model\\'s predictions. The newly determined ion transport coefficients are used as part of a previously developed numerical approach to compute the distribution of charged species in a freely propagating premixed lean CH4/O2 flame. Since a significant scatter of polarizability data exists in the literature, the effects of changes in polarizability on ion transport properties and the spatial distribution of ions in flames are explored. Our analysis shows that changes in polarizability propagate with decreasing effect from binary transport coefficients to species number densities. We conclude that the chosen polarizability value has a limited effect on the ion distribution in freely propagating flames. We expect that the modelling framework proposed here will benefit future efforts in modelling the effect of external voltages on flames. Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/13647830.2015.1090018. © 2015 Taylor & Francis.

  19. Modeling the Lithium Ion Battery

    Science.gov (United States)

    Summerfield, John

    2013-01-01

    The lithium ion battery will be a reliable electrical resource for many years to come. A simple model of the lithium ions motion due to changes in concentration and voltage is presented. The battery chosen has LiCoO[subscript 2] as the cathode, LiPF[subscript 6] as the electrolyte, and LiC[subscript 6] as the anode. The concentration gradient and…

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

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

    Science.gov (United States)

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

    2012-04-01

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

  2. SPEEDUPtrademark ion exchange column model

    International Nuclear Information System (INIS)

    Hang, T.

    2000-01-01

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUptrademark software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLigtrademark ion exchange resins, once the experimental data are complete

  3. Ion implantation induced blistering of rutile single crystals

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  4. Single Ion Trapping for the Enriched Xenon Observatory

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-28

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

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

    International Nuclear Information System (INIS)

    Bolle, J.

    1998-06-01

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

  6. Quantifying He-point defect interactions in Fe through coordinated experimental and modeling studies of He-ion implanted single-crystal Fe

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xunxiang, E-mail: xunxianghu@berkeley.edu [Department of Nuclear Engineering, University of California, Berkeley, CA 94720-1730 (United States); Xu, Donghua; Wirth, Brian D. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720-1730 (United States); Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States)

    2013-11-15

    Understanding the effects of helium on the microstructural evolution and mechanical properties of structural materials are among the most challenging issues in fusion materials research. In this work, we combine thermal helium desorption spectroscopy (THDS) with positron annihilation spectroscopy (PAS) and a spatially dependent cluster dynamics model to investigate the energetics of helium-point defect interactions in helium-implanted single-crystal iron. The combination of modeling and thermal desorption measurements allows identification of the binding energies of small He–V clusters, the migration energy of single vacancy and possible mechanisms (e.g., shrinkage of He{sub 3}V{sub 2} clusters) responsible for measured Helium desorption peaks, and the effect of impurities (e.g., carbon) on these values. Furthermore, the model predicts the depth dependence of the helium and helium–vacancy clusters as a function of time and temperature during the thermal desorption measurement. Here, we report the THDS measurement results as a function of He implantation energy from 10 to 40 keV at a fluence level of 1 × 10{sup 15} He/cm{sup 2}, along with selected PAS measurements. The experimental results are compared to the modeling predictions to evaluate the extent to which self-consistent values of the He-point defect binding and interaction energies and diffusivities can explain the data.

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  8. AFM studies on heavy ion irradiated YBCO single crystals

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  9. Sputtering of Au induced by single Xe ion impacts

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  10. Plastic Flow Induced by Single Ion Impacts on Gold

    International Nuclear Information System (INIS)

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

    1996-01-01

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

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

    International Nuclear Information System (INIS)

    Ohdomari, Iwao

    2008-01-01

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

  12. Assessing Model Characterization of Single Source ...

    Science.gov (United States)

    Aircraft measurements made downwind from specific coal fired power plants during the 2013 Southeast Nexus field campaign provide a unique opportunity to evaluate single source photochemical model predictions of both O3 and secondary PM2.5 species. The model did well at predicting downwind plume placement. The model shows similar patterns of an increasing fraction of PM2.5 sulfate ion to the sum of SO2 and PM2.5 sulfate ion by distance from the source compared with ambient based estimates. The model was less consistent in capturing downwind ambient based trends in conversion of NOX to NOY from these sources. Source sensitivity approaches capture near-source O3 titration by fresh NO emissions, in particular subgrid plume treatment. However, capturing this near-source chemical feature did not translate into better downwind peak estimates of single source O3 impacts. The model estimated O3 production from these sources but often was lower than ambient based source production. The downwind transect ambient measurements, in particular secondary PM2.5 and O3, have some level of contribution from other sources which makes direct comparison with model source contribution challenging. Model source attribution results suggest contribution to secondary pollutants from multiple sources even where primary pollutants indicate the presence of a single source. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, deci

  13. Quantum criticality of a spin-1 XY model with easy-plane single-ion anisotropy via a two-time Green function approach avoiding the Anderson-Callen decoupling

    Science.gov (United States)

    Mercaldo, M. T.; Rabuffo, I.; De Cesare, L.; Caramico D'Auria, A.

    2016-04-01

    In this work we study the quantum phase transition, the phase diagram and the quantum criticality induced by the easy-plane single-ion anisotropy in a d-dimensional quantum spin-1 XY model in absence of an external longitudinal magnetic field. We employ the two-time Green function method by avoiding the Anderson-Callen decoupling of spin operators at the same sites which is of doubtful accuracy. Following the original Devlin procedure we treat exactly the higher order single-site anisotropy Green functions and use Tyablikov-like decouplings for the exchange higher order ones. The related self-consistent equations appear suitable for an analysis of the thermodynamic properties at and around second order phase transition points. Remarkably, the equivalence between the microscopic spin model and the continuous O(2) -vector model with transverse-Ising model (TIM)-like dynamics, characterized by a dynamic critical exponent z=1, emerges at low temperatures close to the quantum critical point with the single-ion anisotropy parameter D as the non-thermal control parameter. The zero-temperature critic anisotropy parameter Dc is obtained for dimensionalities d > 1 as a function of the microscopic exchange coupling parameter and the related numerical data for different lattices are found to be in reasonable agreement with those obtained by means of alternative analytical and numerical methods. For d > 2, and in particular for d=3, we determine the finite-temperature critical line ending in the quantum critical point and the related TIM-like shift exponent, consistently with recent renormalization group predictions. The main crossover lines between different asymptotic regimes around the quantum critical point are also estimated providing a global phase diagram and a quantum criticality very similar to the conventional ones.

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

    Science.gov (United States)

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

    2013-09-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. Cavity QED with single trapped Ca+-ions

    International Nuclear Information System (INIS)

    Mundt, A.B.

    2003-02-01

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

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

    International Nuclear Information System (INIS)

    Weis, Christoph D.

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Christoph D.

    2011-10-04

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

  19. Resonator QED experiments with single 40Ca+ ions

    International Nuclear Information System (INIS)

    Lange, B.

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-01

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

  1. Design of a single ion facility and its applications

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  2. Design of a single ion facility and its applications

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  4. Modeling of neutral beam ion loss from CHS plasmas

    International Nuclear Information System (INIS)

    Darrow, D.S.; Isobe, Mitsutaka; Sasao, Mamiko; Kondo, T.

    2000-01-01

    Beam ion loss measurements from Compact Helical System (CHS) plasmas under a variety of conditions show a strong loss of ions in the range of pitch angles corresponding to transition orbits at the probe location. A numerical model has been developed which includes the beam ion orbits, and details of the detector, plasma, vessel, and neutral beam geometry. From this, the expected classical (i.e. collisionless single particle orbit) signal at the detector can be computed. Preliminary comparisons between the experimental data and model predictions indicate that the classical behavior of the orbits and the machine geometry are insufficient to explain the observations. (author)

  5. A theoretical model of a liquid metal ion source

    International Nuclear Information System (INIS)

    Kingham, D.R.; Swanson, L.W.

    1984-01-01

    A model of liquid metal ion source (LMIS) operation has been developed which gives a consistent picture of three different aspects of LMI sources: (i) the shape and size of the ion emitting region; (ii) the mechanism of ion formation; (iii) properties of the ion beam such as angular intensity and energy spread. It was found that the emitting region takes the shape of a jet-like protrusion on the end of a Taylor cone with ion emission from an area only a few tens of A across, in agreement with recent TEM pictures by Sudraud. This is consistent with ion formation predominantly by field evaporation. Calculated angular intensities and current-voltage characteristics based on our fluid dynamic jet-like protrusion model agree well with experiment. The formation of doubly charged ions is attributed to post-ionization of field evaporated singly charged ions and an apex field strength of about 2.0 V A -1 was calculated for a Ga source. The ion energy spread is mainly due to space charge effects, it is known to be reduced for doubly charged ions in agreement with this post-ionization mechanism. (author)

  6. Single ionization of diatomic molecules by bare ion impact

    International Nuclear Information System (INIS)

    Purkait, M; Mandal, C R

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    International Nuclear Information System (INIS)

    Mohan, M.M.; Griffin, A.

    1985-01-01

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

  9. An ion displacement membrame model.

    Science.gov (United States)

    Hladky, S B; Harris, J D

    1967-09-01

    The usual assumption in treating the diffusion of ions in an electric field has been that the movement of each ion is independent of the movement of the others. The resulting equation for diffusion by a succession of spontaneous jumps has been well stated by Parlin and Eyring. This paper will consider one simple case in which a different assumption is reasonable. Diffusion of monovalent positive ions is considered as a series of jumps from one fixed negative site to another. The sites are assumed to be full (electrical neutrality). Interaction occurs by the displacement of one ion by another. An ion leaves a site if and only if another ion, not necessarily of the same species, attempts to occupy the same site. Flux ratios and net fluxes are given as functions of the electrical potential, concentration ratios, and number of sites encountered in crossing the membrane. Quantitative comparisons with observations of Hodgkin and Keynes are presented.

  10. Towards a precise measurement of atomic parity violation in a single Ra+ ion

    International Nuclear Information System (INIS)

    Nuñez Portela, M.; Berg, J. E. van den; Bekker, H.; Böll, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W.

    2013-01-01

    A single trapped Ra  +  (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z 3 . This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba  +  ions as a precursor for radioactive Ra  +  . Online laser spectroscopy of the isotopes 209 − 214 Ra  +  in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra  +  ion could function as a very stable clock.

  11. Towards a precise measurement of atomic parity violation in a single Ra{sup +} ion

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Portela, M., E-mail: nunez@kvi.nl; Berg, J. E. van den; Bekker, H.; Boell, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W. [Kernfysisch Versneller Instituut (KVI) (Netherlands)

    2013-03-15

    A single trapped Ra{sup + } (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z{sup 3}. This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba{sup + } ions as a precursor for radioactive Ra{sup + }. Online laser spectroscopy of the isotopes {sup 209 - 214}Ra{sup + } in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra{sup + } ion could function as a very stable clock.

  12. Broadband Dielectric Spectroscopy and Quasi-Elastic Neutron Scattering on Single-Ion Polymer Conductors

    Science.gov (United States)

    Soles, Christopher; Peng, Hua-Gen; Page, Kirt; Snyder, Chad; Pandy, Ashoutosh; Jeong, Youmi; Runt, James; NIST Collaboration; Pennsylvania Collaboration

    2011-03-01

    The application of solid polymer electrolytes in rechargeable batteries has not been fully realized after decades of research due to its low conductivity. Dramatic increases of the ion conductivity are needed and this progress requires the understanding of conduction mechanism. We address this topic in two fronts, namely, the effect of plasticizer additives and geometric confinement on the charge transfer mechanism. To this end, we combine broadband dielectric spectroscopy (BDS) to characterize the ion mobility and quasi-elastic neutron scattering (QENS) to quantify segmental motion on a single-ion model polymer electrolyte. Deuterated small molecules were used as plasticizers so that the segmental motion of the polymer electrolyte could be monitored by QENS to understand the mechanism behind the increased conductivity. Anodic aluminum oxide (AAO) membranes with well defined channel sizes are used as the matrix to study the transport of ions solvated in a 1D polymer electrolyte.

  13. Interaction of singly and multiply charged ions with a lithium-fluoride surface

    International Nuclear Information System (INIS)

    Wirtz, L.

    2001-10-01

    Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the attraction due to the self-image potential. In a simulation that treats electronic and nuclear dynamics simultaneously, we show that the image attraction dominates over the repulsive force. Backscattering of very slow multiply charged projectiles high above the surface without touching it ('trampoline effect') does not take place. Instead, the projectile ion penetrates into the surface or is reflected due to close binary collision with surface ions. The case of a singly charged ion in front of an LiF surface is within the reach of ab-initio calculations. We use a multi-configuration self consistent field (MCSCF) and a multi-reference configuration interaction (MR-CI) method to calculate adiabatic potential energy curves for a system consisting of the projectile ion and an embedded cluster of surface ions. With increasing cluster size, the energy levels of the embedded cluster converge towards the band structure of the infinitely extended solid. Due to

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  15. Modeling of ion beam surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Stinnett, R W [Quantum Manufacturing Technologies, Inc., Albuquerque, NM (United States); Maenchen, J E; Renk, T J [Sandia National Laboratories, Albuquerque, NM (United States); Struve, K W [Mission Research Corporation, Albuquerque, NM (United States); Campbell, M M [PASTDCO, Albuquerque, NM (United States)

    1997-12-31

    The use of intense pulsed ion beams is providing a new capability for surface engineering based on rapid thermal processing of the top few microns of metal, ceramic, and glass surfaces. The Ion Beam Surface Treatment (IBEST) process has been shown to produce enhancements in the hardness, corrosion, wear, and fatigue properties of surfaces by rapid melt and re-solidification. A new code called IBMOD was created, enabling the modeling of intense ion beam deposition and the resulting rapid thermal cycling of surfaces. This code was used to model the effect of treatment of aluminum, iron, and titanium using different ion species and pulse durations. (author). 3 figs., 4 refs.

  16. Heisenberg magnetic chain with single-ion easy-plane anisotropy: Hubbard operators approach

    International Nuclear Information System (INIS)

    Spirin, D.V.; Fridman, Y.A.

    2003-01-01

    We investigate the gap in excitation spectrum of one-dimensional S=1 ferro- and antiferromagnets with easy-plane single-ion anisotropy. The self-consistent modification of Hubbard operators approach which enables to account single-site term exactly is used. For antiferromagnetic model we found Haldane phase that exists up to point D=4J (where D is anisotropy parameter, J is exchange coupling), while quadrupolar phase realizes at larger values of anisotropy. Our results specify those of Golinelli et al. (Phys. Rev. B. 45 (1992) 9798), where similar model was studied. Besides the method gives gap value closer to numerical estimations than usual spin-wave theories

  17. Single-ion quantum lock-in amplifier.

    Science.gov (United States)

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

    2011-05-05

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Jeffrey C. McCallum

    2012-01-01

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

  20. Anisotropy effect of crater formation on single crystal silicon surface under intense pulsed ion beam irradiation

    Science.gov (United States)

    Shen, Jie; Yu, Xiao; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Liang, Guoying; Yu, Xiang; Huang, Wanying; Shahid, Ijaz; Zhang, Xiaofu; Yan, Sha; Le, Xiaoyun

    2018-04-01

    Due to the induced extremely fast thermal and dynamic process, Intense Pulsed Ion Beam (IPIB) is widely applied in material processing, which can bring enhanced material performance and surface craters as well. To investigate the craters' formation mechanism, a specific model was built with Finite Element Methods (FEM) to simulate the thermal field on irradiated single crystal silicon. The direct evidence for the existence of the simulated 6-fold rotational symmetric thermal distribution was provided by electron microscope images obtained on single crystal silicon. The correlation of the experiment and simulation is of great importance to understand the interaction between IPIB and materials.

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

    KAUST Repository

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2017-05-01

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

  4. Identification and modelling of Lithium ion battery

    International Nuclear Information System (INIS)

    Tsang, K.M.; Sun, L.; Chan, W.L.

    2010-01-01

    A universal battery model for the charging process has been identified for Lithium ion battery working at constant temperature. Mathematical models are fitted to different collected charging profiles using the least squares algorithm. With the removal of the component which is related to the DC resistance of the battery, a universal model can be fitted to predict profiles of different charging rates after time scaling. Experimental results are included to demonstrate the goodness of fit of the model at different charging rates and for batteries of different capacities. Comparison with standard electrical-circuit model is also presented. With the proposed model, it is possible to derive more effective way to monitor the status of Lithium ion batteries, and to develop a universal quick charger for different capacities of batteries to result with a more effective usage of Lithium ion batteries.

  5. Scattering of atomic and molecular ions from single crystal surfaces of Cu, Ag and Fe

    International Nuclear Information System (INIS)

    Zoest, J.M. van.

    1986-01-01

    This thesis deals with analysis of crystal surfaces of Cu, Ag and Fe with Low Energy Ion scattering Spectroscopy (LEIS). Different atomic and molecular ions with fixed energies below 7 keV are scattered by a metal single crystal (with adsorbates). The energy and direction of the scattered particles are analysed for different selected charge states. In that way information can be obtained concerning the composition and atomic and electronic structure of the single crystal surface. Energy spectra contain information on the composition of the surface, while structural atomic information is obtained by direction measurements (photograms). In Ch.1 a description is given of the experimental equipment, in Ch.2 a characterization of the LEIS method. Ch.3 deals with the neutralization of keV-ions in surface scattering. Two different ways of data interpretation are presented. First a model is treated in which the observed directional dependence of neutralization action of the first atom layer of the surface is presented by a laterally varying thickness of the neutralizing layer. Secondly it is shown that the data can be reproduced by a more realistic, physical model based on atomic transition matrix elements. In Ch.4 the low energy hydrogen scattering is described. The study of the dissociation of H 2 + at an Ag surface r0230ted in a model based on electronic dissociation, initialized by electron capture into a repulsive (molecular) state. In Ch.5 finally the method is applied to the investigation of the surface structure of oxidized Fe. (Auth.)

  6. Analysis of model interfaces for Li ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Seemayer, Andreas; Pareek, Aparna; Vogel, Dirk; Rohwerder, Michael; Renner, Frank [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    2010-07-01

    Lithium ion batteries are the most promising power source for future electromobility applications. Therefore a better understanding of the basic processes in Lithium ion batteries is needed. Especially nowadays research projects aim to improve real systems in terms of higher rate capability, cycle life, safety and operating temperature. Following the surface science approach we focus on the investigation of single crystal model systems of possible anode and cathode materials and electrode/solid electrolyte interfaces prepared by electrochemical deposition, molecular beam epitaxy or pulsed laser deposition.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  8. Electronic properties of single Ge/Si quantum dot grown by ion beam sputtering deposition.

    Science.gov (United States)

    Wang, C; Ke, S Y; Yang, J; Hu, W D; Qiu, F; Wang, R F; Yang, Y

    2015-03-13

    The dependence of the electronic properties of a single Ge/Si quantum dot (QD) grown by the ion-beam sputtering deposition technique on growth temperature and QD diameter is investigated by conductive atomic force microscopy (CAFM). The Si-Ge intermixing effect is demonstrated to be important for the current distribution of single QDs. The current staircase induced by the Coulomb blockade effect is observed at higher growth temperatures (>700 °C) due to the formation of an additional barrier between dislocated QDs and Si substrate for the resonant tunneling of holes. According to the proposed single-hole-tunneling model, the fact that the intermixing effect is observed to increase as the incoherent QD size decreases may explain the increase in the starting voltage of the current staircase and the decrease in the current step width.

  9. Ion spectroscopy for improvement of the physical beam model for therapy planning in ion beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Arico, Giulia

    2016-11-23

    Helium and carbon ions enable a more conformal dose distribution, narrower penumbra and higher relative biological effectiveness than photon and proton radiotherapy. However, they may undergo nuclear fragmentation in the patient tissues and the arising secondary fragments affect the delivered biological dose distributions. Currently there is a lack of data regarding ion nuclear fragmentation. One reason is the large size (up to some meters) of the experimental setups required for the investigations. In this thesis a new method is presented, which makes use of versatile pixelated semiconductor detectors (Timepix). This method is based on tracking of single particles and pattern recognition of their signals in the detectors. Measurements were performed at the HIT facility. The mixed radiation field arising from 430 MeV/u carbon ion beams and 221 MeV/u helium ion beams in water and in PMMA targets was investigated. The amounts of primary (carbon or helium) ions detected behind targets with the same water equivalent thickness (WET) were found to be in agreement within the statistical uncertainties. However, more fragments (differences up to 20% in case of H) and narrower lateral particle distributions were measured behind the PMMA than the water targets. The spectra of ions behind tissue surrogates and corresponding water targets with the same WET were analysed. The results obtained with adipose and inner bone surrogates and with the equivalent water phantoms were found to be consistent within the uncertainties. Significant differences in the results were observed in the case of lung and cortical bone surrogates when compared to the water phantoms. The experimental results were compared to FLUKA Monte Carlo simulations. This comparison could contribute to enhance the ion interaction models currently implemented for {sup 12}C and {sup 4}He ion beams.

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

    Directory of Open Access Journals (Sweden)

    Katia eHiersemenzel

    2013-09-01

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

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

    International Nuclear Information System (INIS)

    Ordonez, C.A.

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-24

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

  14. Ionization in matrix-assisted laser desorption/ionization: singly charged molecular ions are the lucky survivors.

    Science.gov (United States)

    Karas, M; Glückmann, M; Schäfer, J

    2000-01-01

    A new model for the ionization processes in UV matrix-assisted laser desorption/ionization (MALDI) which accounts for the major phenomena observed is presented and discussed. The model retains elements of earlier approaches, such as photoionization and photochemical reactions, but it redefines these in the light of new working questions, most importantly why only singly charged ions are detected. Based on experimental evidence, the formation of singly and multiply charged clusters by a deficiency/excess of ions and also by photoionization and subsequent photochemical processes is pointed out to be the major ionization processes, which typically occur in parallel. The generation of electrons and their partial loss into the surrounding vacuum and solid, on the one hand, results in a positively charged ion-neutral plume facilitating a high overall ionization yield. On the other hand, these electrons, and also the large excess of protonated matrix ions in the negative ion mode, induce effective ion reneutralization in the plume. These neutralization processes are most effective for the highly charged cluster ions initially formed. Their fragmentation behaviour is evidenced in fast metastable fragmentation characteristics and agrees well with an electron capture dissociation mechanism and the enthalpy transfer upon neutralization forms the rationale for the prominent fragmentation and intense chemical noise accompanying successful MALDI. Within the course of the paper, cross-correlations with other desorption/ionization techniques and with earlier discussions on their mechanisms are drawn. Copyright 2000 John Wiley & Sons, Ltd.

  15. Live cell imaging combined with high-energy single-ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Na; Du, Guanghua, E-mail: gh-du@impcas.ac.cn; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Guo, Jinlong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Northwest Normal University, Lanzhou (China); Chen, Hao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Institute of Nuclear Science and Technology, University of Lanzhou, Lanzhou (China)

    2016-03-15

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10{sup −3} s{sup −1} and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10{sup −2} s{sup −1}.

  16. Live cell imaging combined with high-energy single-ion microbeam

    International Nuclear Information System (INIS)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe; Guo, Jinlong; Chen, Hao

    2016-01-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10"−"3 s"−"1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10"−"2 s"−"1.

  17. Live cell imaging combined with high-energy single-ion microbeam

    Science.gov (United States)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Guo, Jinlong; Wu, Ruqun; Chen, Hao; Wei, Junzhe

    2016-03-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10-3 s-1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10-2 s-1.

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

    Science.gov (United States)

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

    2018-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2018-03-01

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

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

    Science.gov (United States)

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

    2018-06-01

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

  1. The Acute Toxicity of Major Ion Salts to Ceriodaphnia dubia. III. Mathematical models for mixture toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset concerns the development of models for describing the acute toxicity of major ions to Ceriodaphnia dubia using data from single salt tests and binary...

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

    National Research Council Canada - National Science Library

    Florjanczyk, Zbigniew

    2008-01-01

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

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

    CERN Document Server

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

    2003-01-01

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

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

    CERN Document Server

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  6. Single-tier city logistics model for single product

    Science.gov (United States)

    Saragih, N. I.; Nur Bahagia, S.; Suprayogi; Syabri, I.

    2017-11-01

    This research develops single-tier city logistics model which consists of suppliers, UCCs, and retailers. The problem that will be answered in this research is how to determine the location of UCCs, to allocate retailers to opened UCCs, to assign suppliers to opened UCCs, to control inventory in the three entities involved, and to determine the route of the vehicles from opened UCCs to retailers. This model has never been developed before. All the decisions will be simultaneously optimized. Characteristic of the demand is probabilistic following a normal distribution, and the number of product is single.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  8. Electrostatic ion thrusters - towards predictive modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kalentev, O.; Matyash, K.; Duras, J.; Lueskow, K.F.; Schneider, R. [Ernst-Moritz-Arndt Universitaet Greifswald, D-17489 (Germany); Koch, N. [Technische Hochschule Nuernberg Georg Simon Ohm, Kesslerplatz 12, D-90489 Nuernberg (Germany); Schirra, M. [Thales Electronic Systems GmbH, Soeflinger Strasse 100, D-89077 Ulm (Germany)

    2014-02-15

    The development of electrostatic ion thrusters so far has mainly been based on empirical and qualitative know-how, and on evolutionary iteration steps. This resulted in considerable effort regarding prototype design, construction and testing and therefore in significant development and qualification costs and high time demands. For future developments it is anticipated to implement simulation tools which allow for quantitative prediction of ion thruster performance, long-term behavior and space craft interaction prior to hardware design and construction. Based on integrated numerical models combining self-consistent kinetic plasma models with plasma-wall interaction modules a new quality in the description of electrostatic thrusters can be reached. These open the perspective for predictive modeling in this field. This paper reviews the application of a set of predictive numerical modeling tools on an ion thruster model of the HEMP-T (High Efficiency Multi-stage Plasma Thruster) type patented by Thales Electron Devices GmbH. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Indian Academy of Sciences (India)

    Unknown

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

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

    DEFF Research Database (Denmark)

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

    1996-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

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

    CERN Document Server

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

    2002-01-01

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

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

    Science.gov (United States)

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

    2011-10-05

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

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

    Science.gov (United States)

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

    2014-04-01

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

  20. Asymptotic analysis of an ion extraction model

    International Nuclear Information System (INIS)

    Ben Abdallah, N.; Mas-Gallic, S.; Raviart, P.A.

    1993-01-01

    A simple model for ion extraction from a plasma is analyzed. The order of magnitude of the plasma parameters leads to a singular perturbation problem for a semilinear elliptic equation. We first prove existence of solutions for the perturbed problem and uniqueness under certain conditions. Then we prove the convergence of these solutions, when the parameters go to zero, towards the solution of a Child-Langmuir problem

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. A model for negative ion extraction and comparison of negative ion optics calculations to experimental results

    International Nuclear Information System (INIS)

    Pamela, J.

    1990-10-01

    Negative ion extraction is described by a model which includes electron diffusion across transverse magnetic fields in the sheath. This model allows a 2-Dimensional approximation of the problem. It is used to introduce electron space charge effects in a 2-D particle trajectory code, designed for negative ion optics calculations. Another physical effect, the stripping of negative ions on neutral gas atoms, has also been included in our model; it is found to play an important role in negative ion optics. The comparison with three sets of experimental data from very different negative ion accelerators, show that our model is able of accurate predictions

  3. Extracting Models in Single Molecule Experiments

    Science.gov (United States)

    Presse, Steve

    2013-03-01

    Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

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

    Directory of Open Access Journals (Sweden)

    Masaaki Omichi

    2014-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

  6. The nuclear single particle model

    International Nuclear Information System (INIS)

    Mang, H.

    1985-01-01

    Twenty years ago in December 1963 one half of the Nobel prize in Physics was awarded to Maria Goeppert-Mayer and Johannes Daniel Jensen for their work on the nuclear shell model. They suggested independently that a strong spin-orbit force with the opposite sign of the one known from atomic physics should be added to the shell-model potential. This proved to be the crucial new idea, because then all the bits of and pieces of evidence that had accumulated over the years fell into place. The author begins with the basic assumption: In a nucleus nucleons move almost independently of each other in an average or shell-model potential. He then provides experimental evidence plausibility arguments and mathematical deductions

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

    Science.gov (United States)

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

    2017-08-01

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

  8. Modeling ion exchange in clinoptilolite using the EQ3/6 geochemical modeling code

    International Nuclear Information System (INIS)

    Viani, B.E.; Bruton, C.J.

    1992-06-01

    Assessing the suitability of Yucca Mtn., NV as a potential repository for high-level nuclear waste requires the means to simulate ion-exchange behavior of zeolites. Vanselow and Gapon convention cation-exchange models have been added to geochemical modeling codes EQ3NR/EQ6, allowing exchange to be modeled for up to three exchangers or a single exchanger with three independent sites. Solid-solution models that are numerically equivalent to the ion-exchange models were derived and also implemented in the code. The Gapon model is inconsistent with experimental adsorption isotherms of trace components in clinoptilolite. A one-site Vanselow model can describe adsorption of Cs or Sr on clinoptilolite, but a two-site Vanselow exchange model is necessary to describe K contents of natural clinoptilolites

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

    Science.gov (United States)

    Samaj, Ladislav

    2013-09-01

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

  10. On the calculation of single ion activity coefficients in homogeneous ionic systems by application of the grand canonical ensemble

    DEFF Research Database (Denmark)

    Sloth, Peter

    1993-01-01

    The grand canonical ensemble has been used to study the evaluation of single ion activity coefficients in homogeneous ionic fluids. In this work, the Coulombic interactions are truncated according to the minimum image approximation, and the ions are assumed to be placed in a structureless......, homogeneous dielectric continuum. Grand canonical ensemble Monte Carlo calculation results for two primitive model electrolyte solutions are presented. Also, a formula involving the second moments of the total correlation functions is derived from fluctuation theory, which applies for the derivatives...... of the individual ionic activity coefficients with respect to the total ionic concentration. This formula has previously been proposed on the basis of somewhat different considerations....

  11. Monte Carlo modeling of ion beam induced secondary electrons

    Energy Technology Data Exchange (ETDEWEB)

    Huh, U., E-mail: uhuh@vols.utk.edu [Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840 (United States); Cho, W. [Electrical and Computer Engineering, University of Tennessee, Knoxville, TN 37996-2100 (United States); Joy, D.C. [Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840 (United States); Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2016-09-15

    Ion induced secondary electrons (iSE) can produce high-resolution images ranging from a few eV to 100 keV over a wide range of materials. The interpretation of such images requires knowledge of the secondary electron yields (iSE δ) for each of the elements and materials present and as a function of the incident beam energy. Experimental data for helium ions are currently limited to 40 elements and six compounds while other ions are not well represented. To overcome this limitation, we propose a simple procedure based on the comprehensive work of Berger et al. Here we show that between the energy range of 10–100 keV the Berger et al. data for elements and compounds can be accurately represented by a single universal curve. The agreement between the limited experimental data that is available and the predictive model is good, and has been found to provide reliable yield data for a wide range of elements and compounds. - Highlights: • The Universal ASTAR Yield Curve was derived from data recently published by NIST. • IONiSE incorporated with the Curve will predict iSE yield for elements and compounds. • This approach can also handle other ion beams by changing basic scattering profile.

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

    International Nuclear Information System (INIS)

    Hirao, Toshio

    2007-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  14. Single event simulation for memories using accelerated ions

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2010-06-01

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

  17. Dynamics of a single ion in a perturbed Penning trap: Octupolar perturbation

    International Nuclear Information System (INIS)

    Lara, Martin; Salas, J. Pablo

    2004-01-01

    Imperfections in the design or implementation of Penning traps may give rise to electrostatic perturbations that introduce nonlinearities in the dynamics. In this paper we investigate, from the point of view of classical mechanics, the dynamics of a single ion trapped in a Penning trap perturbed by an octupolar perturbation. Because of the axial symmetry of the problem, the system has two degrees of freedom. Hence, this model is ideal to be managed by numerical techniques like continuation of families of periodic orbits and Poincare surfaces of section. We find that, through the variation of the two parameters controlling the dynamics, several periodic orbits emanate from two fundamental periodic orbits. This process produces important changes (bifurcations) in the phase space structure leading to chaotic behavior

  18. Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

    International Nuclear Information System (INIS)

    Kuznetsov, G.F.

    2006-01-01

    Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

  19. X-ray diffraction patterns of single crystals implanted with high-energy light ions

    International Nuclear Information System (INIS)

    Wieteska, K.

    1998-01-01

    X-ray diffraction patterns of silicon and gallium arsenide single crystals implanted with high-energy protons and α-particles were studied. A various models of lattice parameter changes were analysed. The agreement between the simulation and experiment proves that the lattice parameter depth-distribution can be assumed to be proportional to vacancy distribution obtained by Monte-Carlo method and from the Biersack-Ziegler theory. Most of the X-ray experiments were performed using synchrotron source of X-ray radiation in particular in the case of back-reflection and transmission section topographic methods. The new method of direct determination of the implanted ion ranges was proposed using synchrotron radiation back-reflection section topography. A number of new interference phenomena was revealed and explained. These interferences are important in the applications of diffraction theory in studying of the real structure of implanted layers. (author)

  20. Bisimulation for Single-Agent Plausibility Models

    DEFF Research Database (Denmark)

    Andersen, Mikkel Birkegaard; Bolander, Thomas; van Ditmarsch, H.

    2013-01-01

    define a proper notion of bisimulation, and prove that bisimulation corresponds to logical equivalence on image-finite models. We relate our results to other epistemic notions, such as safe belief and degrees of belief. Our results imply that there are only finitely many non-bisimilar single......-agent epistemic plausibility models on a finite set of propositions. This gives decidability for single-agent epistemic plausibility planning....

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  2. How to resolve microsecond current fluctuations in single ion channels: The power of beta distributions

    Science.gov (United States)

    Schroeder, Indra

    2015-01-01

    Abstract A main ingredient for the understanding of structure/function correlates of ion channels is the quantitative description of single-channel gating and conductance. However, a wealth of information provided from fast current fluctuations beyond the temporal resolution of the recording system is often ignored, even though it is close to the time window accessible to molecular dynamics simulations. This kind of current fluctuations provide a special technical challenge, because individual opening/closing or blocking/unblocking events cannot be resolved, and the resulting averaging over undetected events decreases the single-channel current. Here, I briefly summarize the history of fast-current fluctuation analysis and focus on the so-called “beta distributions.” This tool exploits characteristics of current fluctuation-induced excess noise on the current amplitude histograms to reconstruct the true single-channel current and kinetic parameters. A guideline for the analysis and recent applications demonstrate that a construction of theoretical beta distributions by Markov Model simulations offers maximum flexibility as compared to analytical solutions. PMID:26368656

  3. Thermal properties of the mixed spin-1 and spin-3/2 Ising ferrimagnetic system with two different random single-ion anisotropies

    Science.gov (United States)

    Pereira, J. R. V.; Tunes, T. M.; de Arruda, A. S.; Godoy, M.

    2018-06-01

    In this work, we have performed Monte Carlo simulations to study a mixed spin-1 and spin-3/2 Ising ferrimagnetic system on a square lattice with two different random single-ion anisotropies. This lattice is divided in two interpenetrating sublattices with spins SA = 1 in the sublattice A and SB = 3 / 2 in the sublattice B. The exchange interaction between the spins on the sublattices is antiferromagnetic (J single-ion anisotropies, DiA and DjB , on the sublattices A and B, respectively. We have determined the phase diagram of the model in the critical temperature Tc versus strength of the random single-ion anisotropy D plane and we shown that it exhibits only second-order phase transition lines. We also shown that this system displays compensation temperatures for some cases of the random single-ion distribution.

  4. Heavy ion fusion reactions: comparison among different models

    Energy Technology Data Exchange (ETDEWEB)

    Canto, L F; Carlson, B V; Hussein, M S

    1988-03-01

    A comparison among different ion fusion models is presented. In particular, the multistep aspects of the recently proposed Dinucleus Doorway Model are made explicit and the model is confronted with other compound nucleus limitation models. It is suggested that the latter models provide effective one-step descriptions of heavy ion fusion.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  6. Modeling ion sensing in molecular electronics

    International Nuclear Information System (INIS)

    Chen, Caroline J.; Smeu, Manuel; Ratner, Mark A.

    2014-01-01

    We examine the ability of molecules to sense ions by measuring the change in molecular conductance in the presence of such charged species. The detection of protons (H + ), alkali metal cations (M + ), calcium ions (Ca 2+ ), and hydronium ions (H 3 O + ) is considered. Density functional theory (DFT) is used within the Keldysh non-equilibrium Green's function framework (NEGF) to model electron transport properties of quinolinedithiol (QDT, C 9 H 7 NS 2 ), bridging Al electrodes. The geometry of the transport region is relaxed with DFT. The transport properties of the device are modeled with NEGF-DFT to determine if this device can distinguish among the M + + QDT species containing monovalent cations, where M + = H + , Li + , Na + , or K + . Because of the asymmetry of QDT in between the two electrodes, both positive and negative biases are considered. The electron transmission function and conductance properties are simulated for electrode biases in the range from −0.5 V to 0.5 V at increments of 0.1 V. Scattering state analysis is used to determine the molecular orbitals that are the main contributors to the peaks in the transmission function near the Fermi level of the electrodes, and current-voltage relationships are obtained. The results show that QDT can be used as a proton detector by measuring transport through it and can conceivably act as a pH sensor in solutions. In addition, QDT may be able to distinguish among different monovalent species. This work suggests an approach to design modern molecular electronic conductance sensors with high sensitivity and specificity using well-established quantum chemistry

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

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

  8. Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

    Science.gov (United States)

    Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu; Nakamura, Takashi; Asai, Hiroyuki

    Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO 4) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li xMnO 2) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li xMnO 2 cell had 1.4 mA h g -1 (per 1 g of active material, current density: 3.77 μA cm -2), and the Li/PMS-LiClO 4/Li xMnO 2 cell had 1.6 mA h g -1 (current density: 75.3 μA cm -2).

  9. Luminescent single-ion magnets from Lanthanoid(III) complexes with monodentate ketone ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kanetomo, Takuya; Ishida, Takayuki, E-mail: takayuki.ishida@uec.ac.jp [Department of Engineering Science, The University of Electro-Communications, Tokyo (Japan)

    2016-02-01

    We synthesized [Ln{sup III}(hfac){sub 3}(H{sub 2}O)(L)] (abbreviated as Ln-L; Ln = Gd, Tb, Eu; L = DTBK (di-t-butyl ketone), BP (benzophenone)), in which the carbonyl oxygen atom was coordinated to the Ln ion center, despite of such bulky substituents. Their crystal structures were determined by means of X-ray diffraction study. Gd-DTBK is completely isomorphous to the di-t-butyl nitroxide derivative and accordingly can be regarded as a model with the ligand spin masked. The ac magnetic susceptibility measurements on Tb-DTBK and -BP showed frequency dependence, characteristic of single-ion magnets. They also displayed photoluminescence in the solid state at room temperature. The quantum yields of the luminescence of Tb-DTBK and -BP (λ{sub ex} = 360 nm) were improved to 57 and 35%, respectively, from that of the starting material [TbI{sup III}(hfac){sub 3}(H{sub 2}O){sub 2}] (28% at λ{sub ex} = 370 nm). Similarly, the quantum yields for Eu-DTBK and -BP were 8 and 15%, respectively, with λ{sub ex} = 400 nm, while that of the starting material [EuI{sup III}(hfac){sub 3}(H{sub 2}O){sub 2}] was 4% at λ{sub ex}=400 nm.

  10. Ion beam synthesis of buried single crystal erbium silicide

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-15

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

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

    Science.gov (United States)

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

    2013-03-29

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

  16. Single photons, dileptons and hadrons from relativistic heavy ion ...

    Indian Academy of Sciences (India)

    and the transverse expansion of the interacting system is taken into account. The recent estimates .... This value of the critical temperature is motivated by the ... of the photon self energy using a model where interactions have been included.

  17. Preparation and coherent manipulation of pure quantum states of a single molecular ion

    Science.gov (United States)

    Chou, Chin-Wen; Kurz, Christoph; Hume, David B.; Plessow, Philipp N.; Leibrandt, David R.; Leibfried, Dietrich

    2017-05-01

    Laser cooling and trapping of atoms and atomic ions has led to advances including the observation of exotic phases of matter, the development of precision sensors and state-of-the-art atomic clocks. The same level of control in molecules could also lead to important developments such as controlled chemical reactions and sensitive probes of fundamental theories, but the vibrational and rotational degrees of freedom in molecules pose a challenge for controlling their quantum mechanical states. Here we use quantum-logic spectroscopy, which maps quantum information between two ion species, to prepare and non-destructively detect quantum mechanical states in molecular ions. We develop a general technique for optical pumping and preparation of the molecule into a pure initial state. This enables us to observe high-resolution spectra in a single ion (CaH+) and coherent phenomena such as Rabi flopping and Ramsey fringes. The protocol requires a single, far-off-resonant laser that is not specific to the molecule, so many other molecular ions, including polyatomic species, could be treated using the same methods in the same apparatus by changing the molecular source. Combined with the long interrogation times afforded by ion traps, a broad range of molecular ions could be studied with unprecedented control and precision. Our technique thus represents a critical step towards applications such as precision molecular spectroscopy, stringent tests of fundamental physics, quantum computing and precision control of molecular dynamics.

  18. Poster 29. Modelling of ion exchange processes in ultrapure water

    International Nuclear Information System (INIS)

    Berg, A.; Torstenfelt, B.; Fejes, P.; Foutch, G.L.

    1992-01-01

    The ion exchange process of the Reactor Water Clean-up (RWCU) system has been studied to better use the maximum possible exchange capacity of the ion exchange resin. Laboratory data have been correlated with computer simulations of the ion exchange process. Data were correlated using a mixed-bed ion exchange model for ultralow ionic concentrations developed at Oklahoma State University. Experimental results of the ion exchange column operation in the concentration range of 10 -3 M boric acid is compared with the simulated performance predicted by the computer model. The model is found to agree reasonably well with the data. (author)

  19. WINKLER'S SINGLE-PARAMETER SUBGRADE MODEL FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    Page 1 ... corresponding single-parameter Winkler model presented in this work. Keywords: Heterogeneous subgrade, Reissner's simplified continuum, Shear interaction, Simplified continuum, Winkler ... model in practical applications and its long time familiarity among practical engineers, its usage has endured to this date ...

  20. Feasibility of Observing and Characterizing Single Ion Strikes in Microelectronic Components

    International Nuclear Information System (INIS)

    Dingreville, Remi Philippe Michel; Hattar, Khalid Mikhiel; Bufford, Daniel Charles

    2015-01-01

    The transient degradation of semiconductor device performance under irradiation has long been an issue of concern. A single high-energy charged particle can degrade or permanently destroy the microelectronic component, potentially altering the course or function of the systems. Disruption of the the crystalline structure through the introduction of quasi-stable defect structures can change properties from semiconductor to conductor. Typically, the initial defect formation phase is followed by a recovery phase in which defect-defect or defect-dopant interactions modify the characteristics of the damaged structure. In this LDRD Express, in-situ ion irradiation transmission microscopy (TEM) in-situ TEM experiments combined with atomistic simulations have been conducted to determine the feasibility of imaging and characterizing the defect structure resulting from a single cascade in silicon. In-situ TEM experiments have been conducted to demonstrate that a single ion strike can be observed in Si thin films with nanometer resolution in real time using the in-situ ion irradiation transmission electron microscope (I 3 TEM). Parallel to this experimental effort, ion implantation has been numerically simulated using Molecular Dynamics (MD). This numerical framework provides detailed predictions of the damage and follow the evolution of the damage during the first nanoseconds. The experimental results demonstrate that single ion strike can be observed in prototypical semiconductors.

  1. Xenon gas field ion source from a single-atom tip

    Science.gov (United States)

    Lai, Wei-Chiao; Lin, Chun-Yueh; Chang, Wei-Tse; Li, Po-Chang; Fu, Tsu-Yi; Chang, Chia-Seng; Tsong, T. T.; Hwang, Ing-Shouh

    2017-06-01

    Focused ion beam (FIB) systems have become powerful diagnostic and modification tools for nanoscience and nanotechnology. Gas field ion sources (GFISs) built from atomic-size emitters offer the highest brightness among all ion sources and thus can improve the spatial resolution of FIB systems. Here we show that the Ir/W(111) single-atom tip (SAT) can emit high-brightness Xe+ ion beams with a high current stability. The ion emission current versus extraction voltage was analyzed from 150 K up to 309 K. The optimal emitter temperature for maximum Xe+ ion emission was ˜150 K and the reduced brightness at the Xe gas pressure of 1 × 10-4 torr is two to three orders of magnitude higher than that of a Ga liquid metal ion source, and four to five orders of magnitude higher than that of a Xe inductively coupled plasma ion source. Most surprisingly, the SAT emitter remained stable even when operated at 309 K. Even though the ion current decreased with increasing temperature, the current at room temperature (RT) could still reach over 1 pA when the gas pressure was higher than 1 × 10-3 torr, indicating the feasibility of RT-Xe-GFIS for application to FIB systems. The operation temperature of Xe-SAT-GFIS is considerably higher than the cryogenic temperature required for the helium ion microscope (HIM), which offers great technical advantages because only simple or no cooling schemes can be adopted. Thus, Xe-GFIS-FIB would be easy to implement and may become a powerful tool for nanoscale milling and secondary ion mass spectroscopy.

  2. A study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    Science.gov (United States)

    Wright, Kenneth Herbert, Jr.

    1988-01-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory.

  3. Study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    International Nuclear Information System (INIS)

    Wright, K.H. Jr.

    1988-02-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory

  4. Rational design of single-ion magnets and spin qubits based on mononuclear lanthanoid complexes.

    Science.gov (United States)

    Baldoví, José J; Cardona-Serra, Salvador; Clemente-Juan, Juan M; Coronado, Eugenio; Gaita-Ariño, Alejandro; Palii, Andrew

    2012-11-19

    Here we develop a general approach to calculating the energy spectrum and the wave functions of the low-lying magnetic levels of a lanthanoid ion submitted to the crystal field created by the surrounding ligands. This model allows us to propose general criteria for the rational design of new mononuclear lanthanoid complexes behaving as single-molecule magnets (SMMs) or acting as robust spin qubits. Three typical environments exhibited by these metal complexes are considered, namely, (a) square antiprism, (b) triangular dodecahedron, and (c) trigonal prism. The developed model is used to explain the properties of some representative examples showing these geometries. Key questions in this area, such as the chemical tailoring of the superparamagnetic energy barrier, tunneling gap, or spin relaxation time, are discussed. Finally, in order to take into account delocalization and/or covalent effects of the ligands, this point-charge model is complemented with ab initio calculations, which provide accurate information on the charge distribution around the metal, allowing for an explanation of the SMM behavior displayed by some sandwich-type organometallic compounds.

  5. Electron impact single detachment on the F- ions using the heavy ion storage ring CRYRING: cross-section determination

    International Nuclear Information System (INIS)

    Andersson, K.; Hanstorp, D.; Oesterdahl, F.; Danared, H.; Kaellberg, A.

    2001-01-01

    Electron Impact Single Detachment (EISD) of F - has been studied using the heavy ion storage ring CRYRING at the Manne Siegbahn Laboratory, Stockholm, Sweden. F - ions stored in the ring were merged with an electron beam in one of the ring sections. Neutral F atoms produced in the EISD process were detected in the zero-degree direction using a surface barrier detector. The threshold for the detachment process was found to be around 7.6 eV, thus more than twice the binding energy of F - . The cross-sections increased smoothly up to 55 eV where it reached a maximum of 1.9 x 10 -16 cm 2 . At higher energies a slow decrease of the cross-section was observed, which follows the energy dependence predicted by the Bethe-Born approximation. The experiment showed that CRYRING can be used favourably for studies of anions, and several experiments are forthcoming. (orig.)

  6. Modeling all-solid-state Li-ion batteries

    NARCIS (Netherlands)

    Danilov, D.; Niessen, R.A.H.; Notten, P.H.L.

    2011-01-01

    A mathematical model for all-solid-state Li-ion batteries is presented. The model includes the charge transfer kinetics at the electrode/electrolyte interface, diffusion of lithium in the intercalation electrode, and diffusion and migration of ions in the electrolyte. The model has been applied to

  7. Spin models for the single molecular magnet Mn12-AC

    Science.gov (United States)

    Al-Saqer, Mohamad A.

    2005-11-01

    The single molecular magnet (SMM) Mn12-AC attracted the attention of scientists since the discovery of its magnetic hystereses which are accompanied by sudden jumps in magnetic moments at low temperature. Unlike conventional bulk magnets, hysteresis in SMMs is of molecular origin. This qualifies them as candidates for next generation of high density storage media where a molecule which is at most few nanometers in size can be used to store a bit of information. However, the jumps in these hystereses, due to spin tunneling, can lead to undesired loss of information. Mn12-AC molecule contains twelve magnetic ions antiferromagnetically coupled by exchanges leading to S = 10 ground state manifold. The magnetic ions are surrounded by ligands which isolate them magnetically from neighboring molecules. The lowest state of S = 9 manifold is believed to lie at about 40 K above the ground state. Therefore, at low temperatures, the molecule is considered as a single uncoupled moment of spin S = 10. Such model has been used widely to understand phenomena exhibited by the molecule at low temperatures including the tunneling of its spin, while a little attention has been paid for the multi-spin nature of the molecule. Using the 8-spin model, we demonstrate that in order to understand the phenomena of tunneling, a full spin description of the molecule is required. We utilized a calculation scheme where a fraction of energy levels are used in the calculations and the influence of levels having higher energy is neglected. From the dependence of tunnel splittings on the number of states include, we conclude that models based on restricting the number of energy levels (single-spin and 8-spin models) lead to unreliable results of tunnel splitting calculations. To attack the full 12-spin model, we employed the Davidson algorithm to calculated lowest energy levels produced by exchange interactions and single ion anisotropies. The model reproduces the anisotropy properties at low

  8. Visualization of metallodrugs in single cells by secondary ion mass spectrometry imaging.

    Science.gov (United States)

    Wu, Kui; Jia, Feifei; Zheng, Wei; Luo, Qun; Zhao, Yao; Wang, Fuyi

    2017-07-01

    Secondary ion mass spectrometry, including nanoscale secondary ion mass spectrometry (NanoSIMS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), has emerged as a powerful tool for biological imaging, especially for single cell imaging. SIMS imaging can provide information on subcellular distribution of endogenous and exogenous chemicals, including metallodrugs, from membrane through to cytoplasm and nucleus without labeling, and with high spatial resolution and chemical specificity. In this mini-review, we summarize recent progress in the field of SIMS imaging, particularly in the characterization of the subcellular distribution of metallodrugs. We anticipate that the SIMS imaging method will be widely applied to visualize subcellular distributions of drugs and drug candidates in single cells, exerting significant influence on early drug evaluation and metabolism in medicinal and pharmaceutical chemistry. Recent progress of SIMS applications in characterizing the subcellular distributions of metallodrugs was summarized.

  9. Surface structure modification of single crystal graphite after slow, highly charged ion irradiation

    Science.gov (United States)

    Alzaher, I.; Akcöltekin, S.; Ban-d'Etat, B.; Manil, B.; Dey, K. R.; Been, T.; Boduch, P.; Rothard, H.; Schleberger, M.; Lebius, H.

    2018-04-01

    Single crystal graphite was irradiated by slow, highly charged ions. The modification of the surface structure was studied by means of Low-Energy Electron Diffraction. The observed damage cross section increases with the potential energy, i.e. the charge state of the incident ion, at a constant kinetic energy. The potential energy is more efficient for the damage production than the kinetic energy by more than a factor of twenty. Comparison with earlier results hints to a strong link between early electron creation and later target atom rearrangement. With increasing ion fluence, the initially large-scale single crystal is first transformed into μ m-sized crystals, before complete amorphisation takes place.

  10. Development of noise-suppressed detector for single ion hit system

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

    A noise-suppressed detector for single ion detection has been developed, and combined with the heavy ion microbeam apparatus. This detector consists of a pair of micro channel plates (MCP`s) and a very thin carbon foil. The detection signal is formed by the coincidence of the signals from these MCP`s, so that this detector and the coincidence measurement unit can reduce miscounting in the circuit. The detection efficiency for 15 MeV heavy ions was evaluated to be comparable to that of a silicon surface-barrier detector (SSD) and the miscounting rate was 4 orders lower than the noise rate of a single MCP. The rise time of the detection signal was also estimated. (author)

  11. Heavy doping of CdTe single crystals by Cr ion implantation

    Science.gov (United States)

    Popovych, Volodymyr D.; Böttger, Roman; Heller, Rene; Zhou, Shengqiang; Bester, Mariusz; Cieniek, Bogumil; Mroczka, Robert; Lopucki, Rafal; Sagan, Piotr; Kuzma, Marian

    2018-03-01

    Implantation of bulk CdTe single crystals with high fluences of 500 keV Cr+ ions was performed to achieve Cr concentration above the equilibrium solubility limit of this element in CdTe lattice. The structure and composition of the implanted samples were studied using secondary ion mass spectrometry (SIMS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) to characterize the incorporation of chromium into the host lattice and to investigate irradiation-induced damage build-up. It was found that out-diffusion of Cr atoms and sputtering of the targets alter the depth distribution and limit concentration of the projectile ions in the as-implanted samples. Appearance of crystallographically oriented, metallic α-Cr nanoparticles inside CdTe matrix was found after implantation, as well as a strong disorder at the depth far beyond the projected range of the implanted ions.

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  13. Ion mass dependence for low energy channeling in single-wall nanotubes

    International Nuclear Information System (INIS)

    Zheng Liping; Zhu Zhiyuan; Li Yong; Zhu Dezhang; Xia Huihao

    2008-01-01

    An Monte Carlo (MC) simulation program has been used to study ion mass dependence for the low energy channeling of natural- and pseudo-Ar ions in single-wall nanotubes. The MC simulations show that the channeling critical angle Ψ C obeys the (E) -1/2 and the (M 1 ) -1/2 rules, where E is the incident energy and M 1 is the ion mass. The reason for this may be that the motion of the channeled (or de-channeled) ions should be correlated with both the incident energy E and the incident momentum (2M 1 E) 1/2 , in order to obey the conservation of energy and momentum

  14. Calculating tracer currents through narrow ion channels: Beyond the independent particle model.

    Science.gov (United States)

    Coalson, Rob D; Jasnow, David

    2018-06-01

    Discrete state models of single-file ion permeation through a narrow ion channel pore are employed to analyze the ratio of forward to backward tracer current. Conditions under which the well-known Ussing formula for this ratio hold are explored in systems where ions do not move independently through the channel. Building detailed balance into the rate constants for the model in such a way that under equilibrium conditions (equal rate of forward vs. backward permeation events) the Nernst Equation is satisfied, it is found that in a model where only one ion can occupy the channel at a time, the Ussing formula is always obeyed for any number of binding sites, reservoir concentrations of the ions and electric potential difference across the membrane which the ion channel spans, independent of the internal details of the permeation pathway. However, numerical analysis demonstrates that when multiple ions can occupy the channel at once, the nonequilibrium forward/backward tracer flux ratio deviates from the prediction of the Ussing model. Assuming an appropriate effective potential experienced by ions in the channel, we provide explicit formulae for the rate constants in these models. © 2018 IOP Publishing Ltd.

  15. Dimer self-organization of impurity ytterbium ions in synthetic forsterite single crystals

    Science.gov (United States)

    Tarasov, V. F.; Sukhanov, A. A.; Dudnikova, V. B.; Zharikov, E. V.; Lis, D. A.; Subbotin, K. A.

    2017-07-01

    Paramagnetic centers formed by impurity Yb3+ ions in synthetic forsterite (Mg2SiO4) grown by the Czochralski technique are studied by X-band CW and pulsed EPR spectroscopy. These centers are single ions substituting magnesium in two different crystallographic positions denoted M1 and M2, and dimer associates formed by two Yb3+ ions in nearby positions M1. It is established that there is a pronounced mechanism favoring self-organization of ytterbium ions in dimer associates during the crystal growth, and the mechanism of the spin-spin coupling between ytterbium ions in the associate has predominantly a dipole-dipole character, which makes it possible to control the energy of the spin-spin interaction by changing the orientation of the external magnetic field. The structural computer simulation of cluster ytterbium centers in forsterite crystals is carried out by the method of interatomic potentials using the GULP 4.0.1 code (General Utility Lattice Program). It is established that the formation of dimer associates in the form of a chain parallel to the crystallographic axis consisting of two ytterbium ions with a magnesium vacancy between them is the most energetically favorable for ytterbium ions substituting magnesium in the position M1.

  16. History-dependent dynamics in a generic model of ion channels - an analytic study

    Directory of Open Access Journals (Sweden)

    Daniel Soudry

    2010-04-01

    Full Text Available Recent experiments have demonstrated that the timescale of adaptation of single neurons and ion channel populations to stimuli slows down as the length of stimulation increases; in fact, no upper bound on temporal time-scales seems to exist in such systems. Furthermore, patch clamp experiments on single ion channels have hinted at the existence of large, mostly unobservable, inactivation state spaces within a single ion channel. This raises the question of the relation between this multitude of inactivation states and the observed behavior. In this work we propose a minimal model for ion channel dynamics which does not assume any specific structure of the inactivation state space. The model is simple enough to render an analytical study possible. This leads to a clear and concise explanation of the experimentally observed exponential history-dependent relaxation in sodium channels in a voltage clamp setting, and shows that their recovery rate from slow inactivation must be voltage dependent. Furthermore, we predict that history-dependent relaxation cannot be created by overly sparse spiking activity. While the model was created with ion channel populations in mind, its simplicity and genericalness render it a good starting point for modeling similar effects in other systems, and for scaling up to higher levels such as single neurons which are also known to exhibit multiple time scales.

  17. Graphical models for inferring single molecule dynamics

    Directory of Open Access Journals (Sweden)

    Gonzalez Ruben L

    2010-10-01

    Full Text Available Abstract Background The recent explosion of experimental techniques in single molecule biophysics has generated a variety of novel time series data requiring equally novel computational tools for analysis and inference. This article describes in general terms how graphical modeling may be used to learn from biophysical time series data using the variational Bayesian expectation maximization algorithm (VBEM. The discussion is illustrated by the example of single-molecule fluorescence resonance energy transfer (smFRET versus time data, where the smFRET time series is modeled as a hidden Markov model (HMM with Gaussian observables. A detailed description of smFRET is provided as well. Results The VBEM algorithm returns the model’s evidence and an approximating posterior parameter distribution given the data. The former provides a metric for model selection via maximum evidence (ME, and the latter a description of the model’s parameters learned from the data. ME/VBEM provide several advantages over the more commonly used approach of maximum likelihood (ML optimized by the expectation maximization (EM algorithm, the most important being a natural form of model selection and a well-posed (non-divergent optimization problem. Conclusions The results demonstrate the utility of graphical modeling for inference of dynamic processes in single molecule biophysics.

  18. A collisional model for plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Vahedi, V.; Lieberman, M.A.; Alves, M.V.; Verboncoeur, J.P.; Birdsall, C.K.

    1990-01-01

    In plasma immersion ion implantation, a target is immersed in a plasma and a series of negative short pulses are applied to it to implant the ions. A new analytical model is being developed for the high pressure regimes in which the motion of the ions is highly collisional. The model provides values for ion flux, average ion velocity at the target, and sheath edge motion as a function of time. These values are being compared with those obtained from simulation and show good agreement. A review is also given (for comparison) of the earlier work done at low pressures, where the motion of ions in the sheath is collisionless, also showing good agreement between analysis and simulation. The simulation code is PDP1 which utilizes particle-in-cell techniques plus Monte-Carlo simulation of electron-neutral (elastic, excitation and ionization) and ion-neutral (scattering and charge-exchange) collisions

  19. Reorientation of the crystalline planes in confined single crystal nickel nanorods induced by heavy ion irradiation

    International Nuclear Information System (INIS)

    Misra, Abha; Tyagi, Pawan K.; Rai, Padmnabh; Misra, D. S.; Ghatak, Jay; Satyam, P. V.; Avasthi, D. K.

    2006-01-01

    In a recent letter Tyagi et al. [Appl. Phys. Lett. 86, 253110 (2005)] have reported the special orientation of nickel planes inside multiwalled carbon nanotubes (MWCNTs) with respect to the tube axis. Heavy ion irradiation has been performed with 1.5 MeV Au 2+ and 100 MeV Au 7+ ions on these nickel filled MWCNTs at fluences ranging from 10 12 to 10 15 ions/cm 2 at room temperature. Ion-induced modifications have been studied using high-resolution transmission electron microscopy. The diffraction pattern and the lattice imaging showed the presence of ion-induced planar defects on the tube walls and completely amorphized encapsulated nickel nanorods. The results are discussed in terms of thermal spike model

  20. Long-Distance Single Photon Transmission from a Trapped Ion via Quantum Frequency Conversion

    Science.gov (United States)

    Walker, Thomas; Miyanishi, Koichiro; Ikuta, Rikizo; Takahashi, Hiroki; Vartabi Kashanian, Samir; Tsujimoto, Yoshiaki; Hayasaka, Kazuhiro; Yamamoto, Takashi; Imoto, Nobuyuki; Keller, Matthias

    2018-05-01

    Trapped atomic ions are ideal single photon emitters with long-lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables the efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single 40Ca+ ion coupled to an optical cavity over a 10 km optical fiber via frequency conversion from 866 nm to the telecom C band at 1530 nm. We observe nonclassical photon statistics of the direct cavity emission, the converted photons, and the 10 km transmitted photons, as well as the preservation of the photons' temporal shape throughout. This telecommunication-ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation.

  1. Luminescence model with quantum impact parameter for low energy ions

    CERN Document Server

    Cruz-Galindo, H S; Martínez-Davalos, A; Belmont-Moreno, E; Galindo, S

    2002-01-01

    We have modified an analytical model of induced light production by energetic ions interacting in scintillating materials. The original model is based on the distribution of energy deposited by secondary electrons produced along the ion's track. The range of scattered electrons, and thus the energy distribution, depends on a classical impact parameter between the electron and the ion's track. The only adjustable parameter of the model is the quenching density rho sub q. The modification here presented, consists in proposing a quantum impact parameter that leads to a better fit of the model to the experimental data at low incident ion energies. The light output response of CsI(Tl) detectors to low energy ions (<3 MeV/A) is fitted with the modified model and comparison is made to the original model.

  2. Surface analysis of Li-ion battery model anodes

    Energy Technology Data Exchange (ETDEWEB)

    Seemayer, Andreas; Bach, Philipp; Renner, Frank Uwe [Max Planck Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Duesseldorf (Germany)

    2011-07-01

    Lithium ion batteries are the most promising power source for future electromobility applications. Research on the battery systems aims to achieve higher rate capability, cycle life, or better safety. To achieve necessary further improvements a better understanding of the basic processes is needed. Following a surface science approach we focus on the investigation of simple model systems (like single crystals or thin film electrodes) of relevant anode materials. We report investigations of the electrochemical insertion of lithium in Au, Ag, Al, Mg and Si model surfaces, i.e. alloying and dealloying of lithium alloys. As electrolyte we use the ionic liquid 1-Butyl-1-methylpyrrolidinium bis(trifluoromethanesolfonyl)imide (PYR14TFSI) with 0.3M LiTFSI. The electrochemical characterisation is performed by cyclic voltammetry (CV). The surface and film characterisation regarding its geometrical structure is investigated by means of scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM). The chemical composition is characterised ex-situ by photoelectron spectroscopy (PES) and secondary ion mass spectrometry (SIMS).

  3. Ionoluminescence analysis of glass scintillators and application to single-ion-hit real-time detection

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Akihito, E-mail: yokoyama.akihito@jaea.go.jp [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Kada, Wataru [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Satoh, Takahiro; Koka, Masashi [Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Shimada, Keisuke; Yokoata, Yuya; Miura, Kenta; Hanaizumi, Osamu [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)

    2016-03-15

    In this paper, we propose and test a real-time detection system for single-ion hits using mega-electronvolt (MeV)-heavy ions. The system was constructed using G2000 and G9 glass scintillators, as well as an electron-multiplying charge-coupled device (EMCCD) camera combined with an inverted microscope with a 10× objective lens. Commercially available G2000 and G9 glass scintillators, which have been reported to exhibit strong photoluminescence at 489, 543, 585, and 622 nm as a result of the Tb{sup 3+} f–f transition, were employed for highly accurate ionized particle detection. The EMCCD camera had a resolution of 512 × 512 pixels, each with a size of 16 μm × 16 μm, and a maximum linear gain of 8 × 10{sup 5} electrons. For 260-MeV Ne, 3 ion hits/s were detected by our system. The intensity of the ionoluminescence (IL) peak induced by the heavy ions was 140 times the noise intensity. In contrast, the luminous diameter at the full width at half maximum (FWHM) in both the horizontal and vertical directions was calculated to be approximately 4.5 μm. These results suggest that our detection system can accurately detect single-ion hits with a diameter of the order of 1 μm.

  4. The Fabrication of Arrays of Single Ions in Silicon via Ion Implantation

    Science.gov (United States)

    2014-02-01

    necessary in the pursuit of further refinement of the standard model, like the widely publicised search for the Higgs boson [327]. Much of the initial...Detectors 2004. [327] G Abbiendi. Search for the standard model Higgs boson at LEP. Physics Letters B, 565(0):61 – 75, 2003. [328] James F. Ziegler. Particle

  5. Single and binary adsorption of heavy metal ions from aqueous solutions using sugarcane cellulose-based adsorbent.

    Science.gov (United States)

    Wang, Futao; Pan, Yuanfeng; Cai, Pingxiong; Guo, Tianxiang; Xiao, Huining

    2017-10-01

    A high efficient and eco-friendly sugarcane cellulose-based adsorbent was prepared in an attempt to remove Pb 2+ , Cu 2+ and Zn 2+ from aqueous solutions. The effects of initial concentration of heavy metal ions and temperature on the adsorption capacity of the bioadsorbent were investigated. The adsorption isotherms showed that the adsorption of Pb 2+ , Cu 2+ and Zn 2+ followed the Langmuir model and the maximum adsorptions were as high as 558.9, 446.2 and 363.3mg·g -1 , respectively, in single component system. The binary component system was better described with the competitive Langmuir isotherm model. The three dimensional sorption surface of binary component system demonstrated that the presence of Pb 2+ decreased the sorption of Cu 2+ , but the adsorption amount of other metal ions was not affected. The result from SEM-EDAX revealed that the adsorption of metal ions on bioadsorbent was mainly driven by coordination, ion exchange and electrostatic association. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. A classical statistical model of heavy ion collisions

    International Nuclear Information System (INIS)

    Schmidt, R.; Teichert, J.

    1980-01-01

    The use of the computer code TRAJEC which represents the numerical realization of a classical statistical model for heavy ion collisions is described. The code calculates the results of a classical friction model as well as various multi-differential cross sections for heavy ion collisions. INPUT and OUTPUT information of the code are described. Two examples of data sets are given [ru

  7. THE BERTRAND MODEL OF THE SINGLE MARKET

    Directory of Open Access Journals (Sweden)

    Vadasan Ioana

    2010-12-01

    Full Text Available Starting with the signification of the rationality hypothesis when the agent’s contentment is directly affected by the other agents’ decisions, the theory of games defines solutions for solving different situations of conflict. The economic actors have different behaviours of the Single Market. Oligopoly strategic behaviours were analysed by the Bertrand model. The two types revealed in the work show that strategic interactions are sensitive to the companies’ features, products and markets. Regarding the situation when we have an oligopoly competition, the companies make interdependent decisions in the environment affected by risk and uncertainty of the Single Market. For this reason it is an opportunity to study the structure of oligopoly type of of the Single Market with the aid of non – cooperative games.

  8. Ion transport Modeling in a Bipolar Membrane

    International Nuclear Information System (INIS)

    Kim, Jung Soo; Park, Kwang Heon; Kim, Kwang Wook

    2010-01-01

    The COL(Carbonate-based Oxidative Leaching) process is an environmentally-friendly technique for collecting only uranium from spent fuel with oxidation leaching/ precipitation of carbonate solution. The bipolar membrane used for the electrolyte circulation of the salt used in the COL process is a special form of ion exchange membrane which combines CEM(cation exchange membrane) and AEM(anion exchange membrane). After arranging positive ion exchange layer toward negative terminal and positive ion exchange layer toward positive terminal, then supply electricity, water molecules are decomposed into protons and hydroxyl ions by a strong electric field in the transition region inside bipolar membrane.1) In this study, a theoretical approach to increase the efficiency of Na + and NO3 - ion collecting device using bipolar membrane was taken and simulating using the COMSOL program was tried. The details of results are also discussed

  9. Influence of copper single crystal structures on the reflection of low energy hydrogen and helium ions

    International Nuclear Information System (INIS)

    Feijen, H.H.W.

    1975-01-01

    A theoretical basis for the 'wedge-focussing' phenomenon is outlined. Investigations have been made to check up to what extent proton reflection can be simulated by using H 2 + or H 3 + as incident ions and analysing the reflected protons. The results of an experimental study of the influence of surface semi-channels on the reflection of low energy ( + , H 2 + and He + ions from copper single crystals with attention to the wedge-focussing effect are presented (G.T.H.)

  10. Ion Feedback Suppression Using Inclined MCP Holes in a Single-MCP+Micromegas+Pads Detector

    International Nuclear Information System (INIS)

    Va'vra, J.; Sumiyoshi, T.

    2005-01-01

    We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in a presence of magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (Microchannel) plate, a Micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

  11. Single electron attachment and stripping cross sections for relativistic heavy ions

    International Nuclear Information System (INIS)

    Crawford, H.J.

    1979-06-01

    The results of a Bevalac experiment to measure the single electron attachment and stripping cross sections for relativistic (0.5 1 , and fully stripped, N 0 , ion beams emerging from the targets. Separate counters measured the number of ions in each charge state. The ratios N 1 /N 0 for different target thicknesses were fit to a simple growth curve to yield electron attachment and stripping cross sections. The data are compared to relativistic extrapolations of available theories. Clear evidence for two separate attachment processes, radiative and non-radiative, is found. Data are compared to a recently improved formulation for the stripping cross sections

  12. Modification of mechanical properties of single crystal aluminum oxide by ion beam induced structural changes

    International Nuclear Information System (INIS)

    Ensinger, W.; Nowak, R.; Horino, Y.; Baba, K.

    1993-01-01

    The mechanical behaviour of ceramics is essentially determined by their surface qualities. As a surface modification technique, ion implantation provides the possibility to modify the mechanical properties of ceramics. Highly energetic ions are implanted into the near-surface region of a material and modify its composition and structure. Ions of aluminum, oxygen, nickel and tantalum were implanted into single-crystal α-aluminum oxide. Three-point bending tests showed that an increase in flexural strength of up to 30% could be obtained after implantation of aluminum and oxygen. Nickel and tantalum ion implantation increased the fracture toughness. Indentation tests with Knoop and Vickers diamonds and comparison of the lengths of the developed radial cracks showed that ion implantation leads to a reaction in cracking. The observed effects are assigned to radiation induced structural changes of the ceramic. Ion bombardment leads to radiation damage and formation of compressive stress. In case of tantalum implantation, the implanted near-surface zone becomes amorphous. These effects make the ceramic more resistant to fracture. (orig.)

  13. Engineering of electronic properties of single layer graphene by swift heavy ion irradiation

    Science.gov (United States)

    Kumar, Sunil; Kumar, Ashish; Tripathi, Ambuj; Tyagi, Chetna; Avasthi, D. K.

    2018-04-01

    In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.

  14. The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

    Science.gov (United States)

    Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

    2017-10-01

    Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

  15. Ionization and single electron capture in collision of highly charged Ar16+ ions with helium

    International Nuclear Information System (INIS)

    Wang Fei; Gou Bingcong

    2008-01-01

    This paper uses the two-centre atomic orbital close-coupling method to study the ionization and the single electron capture in collision of highly charged Ar 16+ ions with He atoms in the velocity range of 1.2–1.9 a.u. The relative importance of single ionization (SI) to single capture (SC) is explored. The comparison between the calculation and experimental data shows that the SI/SC cross section ratios from this work are in good agreement with experimental data. The total single electron ionization cross sections and the total single electron capture cross sections are also given for this collision. The investigation of the partial electron capture cross section shows a general tendency of capture to larger n and l with increasing velocity from 1.2 to 1.9 a.u

  16. Modeling the Activity of Single Genes

    Science.gov (United States)

    Mjolsness, Eric; Gibson, Michael

    1999-01-01

    the key questions in gene regulation are: What genes are expressed in a certain cell at a certain time? How does gene expression differ from cell to cell in a multicellular organism? Which proteins act as transcription factors, i.e., are important in regulating gene expression? From questions like these, we hope to understand which genes are important for various macroscopic processes. Nearly all of the cells of a multicellular organism contain the same DNA. Yet this same genetic information yields a large number of different cell types. The fundamental difference between a neuron and a liver cell, for example, is which genes are expressed. Thus understanding gene regulation is an important step in understanding development. Furthermore, understanding the usual genes that are expressed in cells may give important clues about various diseases. Some diseases, such as sickle cell anemia and cystic fibrosis, are caused by defects in single, non-regulatory genes; others, such as certain cancers, are caused when the cellular control circuitry malfunctions - an understanding of these diseases will involve pathways of multiple interacting gene products. There are numerous challenges in the area of understanding and modeling gene regulation. First and foremost, biologists would like to develop a deeper understanding of the processes involved, including which genes and families of genes are important, how they interact, etc. From a computation point of view, there has been embarrassingly little work done. In this chapter there are many areas in which we can phrase meaningful, non-trivial computational questions, but questions that have not been addressed. Some of these are purely computational (what is a good algorithm for dealing with a model of type X) and others are more mathematical (given a system with certain characteristics, what sort of model can one use? How does one find biochemical parameters from system-level behavior using as few experiments as possible?). In

  17. Synthesizing single-phase β-FeSi2 via ion beam irradiations of Fe/Si bilayers

    International Nuclear Information System (INIS)

    Milosavljevic, M.; Dhar, S.; Schaaf, P.; Bibic, N.; Lieb, K.P.

    2001-01-01

    This paper presents results on the direct synthesis of the β-FeSi 2 phase by ion beam mixing of Fe/Si bilayers with Xe ions. The influence of the substrate temperature, ion fluence and energy on the growth of this phase was investigated using Rutherford backscattering (RBS), X-ray diffraction (XRD) and conversion electron Moessbauer spectroscopy (CEMS). Complete growth of single-phase β-FeSi 2 was achieved by 205 keV Xe ion irradiation to a fluence of 2x10 16 ions/cm 2 at 600 deg. C. We propose a two-step reaction mechanism involving thermal and ion beam energy deposition

  18. Spin dynamics in the single-ion magnet [Er(W5O18) 2 ] 9 -

    Science.gov (United States)

    Mariani, M.; Borsa, F.; Graf, M. J.; Sanna, S.; Filibian, M.; Orlando, T.; Sabareesh, K. P. V.; Cardona-Serra, S.; Coronado, E.; Lascialfari, A.

    2018-04-01

    In this work we present a detailed NMR and μ+SR investigation of the spin dynamics in the new hydrated sodium salt containing the single-ion magnet [Er(W5O18) 2 ] 9 -. The 1HNMR absorption spectra at various applied magnetic fields present a line broadening on decreasing temperature which indicates a progressive spin freezing of the single-molecule magnetic moments. The onset of quasistatic local magnetic fields, due to spin freezing, is observed also in the muon relaxation curves at low temperature. Both techniques yield a local field distribution of the order of 0.1-0.2 T, which appears to be of dipolar origin. On decreasing the temperature, a gradual loss of the 1HNMR signal intensity is observed, a phenomenon known as wipe-out effect. The effect is analyzed quantitatively on the basis of a simple model which relies on the enhancement of the NMR spin-spin, T2-1, relaxation rate due to the slowing down of the magnetic fluctuations. Measurements of spin-lattice relaxation rate T1-1 for 1HNMR and of the muon longitudinal relaxation rate λ show an increase as the temperature is lowered. However, while for the NMR case the signal is lost before reaching the very slow fluctuation region, the muon spin-lattice relaxation λ can be followed until very low temperatures and the characteristic maximum, reached when the electronic spin fluctuation frequency becomes of the order of the muon Larmor frequency, can be observed. At high temperatures, the data can be well reproduced with a simple model based on a single correlation time τ =τ0exp (Δ /T ) for the magnetic fluctuations. However, to fit the relaxation data for both NMR and μ+SR over the whole temperature and magnetic field range, one has to use a more detailed model that takes into account spin-phonon transitions among the E r3 + magnetic sublevels. A good agreement for both proton NMR and μ+SR relaxation is obtained, which confirms the validity of the energy level scheme previously calculated from an

  19. [Compared Markov with fractal models by using single-channel experimental and simulation data].

    Science.gov (United States)

    Lan, Tonghan; Wu, Hongxiu; Lin, Jiarui

    2006-10-01

    The gating mechanical kinetical of ion channels has been modeled as a Markov process. In these models it is assumed that the channel protein has a small number of discrete conformational states and kinetic rate constants connecting these states are constant, the transition rate constants among the states is independent both of time and of the previous channel activity. It is assumed in Liebovitch's fractal model that the channel exists in an infinite number of energy states, consequently, transitions from one conductance state to another would be governed by a continuum of rate constants. In this paper, a statistical comparison is presented of Markov and fractal models of ion channel gating, the analysis is based on single-channel data from ion channel voltage-dependence K+ single channel of neuron cell and simulation data from three-states Markov model.

  20. Extending the applicability of an open-ring trap to perform experiments with a single laser-cooled ion

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo, J. M.; Colombano, M.; Doménech, J.; Rodríguez, D., E-mail: danielrodriguez@ugr.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada (Spain); Block, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, 55099 Mainz (Germany); Institut für Kernchemie, University of Mainz, 55099 Mainz (Germany); Delahaye, P. [Grand Accélérateur National d’Ions Lourds, 14000 Caen (France)

    2015-10-15

    A special ion trap was initially built up to perform β-ν correlation experiments with radioactive ions. The trap geometry is also well suited to perform experiments with laser-cooled ions, serving for the development of a new type of Penning trap, in the framework of the project TRAPSENSOR at the University of Granada. The goal of this project is to use a single {sup 40}Ca{sup +} ion as detector for single-ion mass spectrometry. Within this project and without any modification to the initial electrode configuration, it was possible to perform Doppler cooling on {sup 40}Ca{sup +} ions, starting from large clouds and reaching single ion sensitivity. This new feature of the trap might be important also for other experiments with ions produced at radioactive ion beam facilities. In this publication, the trap and the laser system will be described, together with their performance with respect to laser cooling applied to large ion clouds down to a single ion.

  1. Damage evolution in Xe-ion irradiated rutile (TiO2) single crystals

    International Nuclear Information System (INIS)

    Li, F.; Sickafus, K.E.; Evans, C.R.; Nastasi, M.

    1999-01-01

    Rutile (TiO 2 ) single crystals with (110) orientation were irradiated with 360 keV Xe 2+ ions at 300 K to fluences ranging from 2 x 10 19 to 1 x 10 20 Xe/m 2 . Irradiated samples were analyzed using: (1) Rutherford backscattering spectroscopy combined with ion channeling analysis (RBS/C); and (2) cross-sectional transmission electron microscopy (XTEM). Upon irradiation to a fluence of 2 x 10 19 Xe/m 2 , the sample thickness penetrated by the implanted ions was observed to consist of three distinct layers: (1) a defect-free layer at the surface (thickness about 12 nm) exhibiting good crystallinity; (2) a second layer with a low density of relatively large-sized defects; and (3) a third layer consisting of a high concentration of small defects. After the fluence was increased to 7 x 10 19 Xe/m 2 , a buried amorphous layer was visible by XTEM. The thickness of the amorphous layer was found to increase with increasing Xe ion fluence. The location of this buried amorphous layer was found to coincide with the measured peak in the Xe concentration (measured by RBS/C), rather than with the theoretical maximum in the displacement damage profile. This observation suggests the implanted Xe ions may serve as nucleation sites for the amorphization transformation. The total thickness of the damaged microstructure due to ion irradiation was always found to be much greater than the projected range of the Xe ions. This is likely due to point defect migration under the high stresses induced by ion implantation

  2. Re-examining the tetraphenyl-arsonium/tetraphenyl-borate (TATB) hypothesis for single-ion solvation free energies

    Science.gov (United States)

    Pollard, Travis P.; Beck, Thomas L.

    2018-06-01

    Attempts to establish an absolute single-ion hydration free energy scale have followed multiple strategies. Two central themes consist of (1) employing bulk pair thermodynamic data and an underlying interfacial-potential-free model to partition the hydration free energy into individual contributions [Marcus, Latimer, and tetraphenyl-arsonium/tetraphenyl-borate (TATB) methods] or (2) utilizing bulk thermodynamic and cluster data to estimate the free energy to insert a proton into water, including in principle an interfacial potential contribution [the cluster pair approximation (CPA)]. While the results for the hydration free energy of the proton agree remarkably well between the three approaches in the first category, the value differs from the CPA result by roughly +10 kcal/mol, implying a value for the effective electrochemical surface potential of water of -0.4 V. This paper provides a computational re-analysis of the TATB method for single-ion free energies using quasichemical theory. A previous study indicated a significant discrepancy between the free energies of hydration for the TA cation and the TB anion. We show that the main contribution to this large computed difference is an electrostatic artifact arising from modeling interactions in periodic boundaries. No attempt is made here to develop more accurate models for the local ion/solvent interactions that may lead to further small free energy differences between the TA and TB ions, but the results clarify the primary importance of interfacial potential effects for analysis of the various free energy scales. Results are also presented, related to the TATB assumption in the organic solvents dimethyl sulfoxide and 1,2-dichloroethane.

  3. A single quark effective potential model

    International Nuclear Information System (INIS)

    Bodmann, B.E.J.; Vasconcellos, C.A.Z.

    1994-01-01

    In the present work we construct a radial spherical symmetric single quark potential model for the nucleon, consistent with asymptotic freedom and confinement. The quark mass enters as potential parameter and that way induces indirectly an isospin dependence in the interaction. As a consequence, a contribution to the negative charge square radius of the neutron arises an an effect of the quark core, which simulates an isospin symmetry breaking effect in the nucleon due to strong interaction. (author)

  4. A double-layer based model of ion confinement in electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, D., E-mail: davidmascali@lns.infn.it; Neri, L.; Celona, L.; Castro, G.; Gammino, S.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Torrisi, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Università Mediterranea di Reggio Calabria, Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile, Via Graziella, I-89100 Reggio Calabria (Italy); Sorbello, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Ingegneria Elettrica Elettronica ed Informatica, Viale Andrea Doria 6, 95125 Catania (Italy)

    2014-02-15

    The paper proposes a new model of ion confinement in ECRIS, which can be easily generalized to any magnetic configuration characterized by closed magnetic surfaces. Traditionally, ion confinement in B-min configurations is ascribed to a negative potential dip due to superhot electrons, adiabatically confined by the magneto-static field. However, kinetic simulations including RF heating affected by cavity modes structures indicate that high energy electrons populate just a thin slab overlapping the ECR layer, while their density drops down of more than one order of magnitude outside. Ions, instead, diffuse across the electron layer due to their high collisionality. This is the proper physical condition to establish a double-layer (DL) configuration which self-consistently originates a potential barrier; this “barrier” confines the ions inside the plasma core surrounded by the ECR surface. The paper will describe a simplified ion confinement model based on plasma density non-homogeneity and DL formation.

  5. Sustained State-Independent Quantum Contextual Correlations from a Single Ion

    Science.gov (United States)

    Leupold, F. M.; Malinowski, M.; Zhang, C.; Negnevitsky, V.; Alonso, J.; Home, J. P.; Cabello, A.

    2018-05-01

    We use a single trapped-ion qutrit to demonstrate the quantum-state-independent violation of noncontextuality inequalities using a sequence of randomly chosen quantum nondemolition projective measurements. We concatenate 53 ×106 sequential measurements of 13 observables, and unambiguously violate an optimal noncontextual bound. We use the same data set to characterize imperfections including signaling and repeatability of the measurements. The experimental sequence was generated in real time with a quantum random number generator integrated into our control system to select the subsequent observable with a latency below 50 μ s , which can be used to constrain contextual hidden-variable models that might describe our results. The state-recycling experimental procedure is resilient to noise and independent of the qutrit state, substantiating the fact that the contextual nature of quantum physics is connected to measurements and not necessarily to designated states. The use of extended sequences of quantum nondemolition measurements finds applications in the fields of sensing and quantum information.

  6. Single-column ion chromatography with determination of hydrazoic acid produced in spent nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Ma Guilan; Tan Shuping

    2006-01-01

    The reaction of hydrazine and its derivative with ammonium metavanadate may produce hydrazoic acid (HN 3 ). A single-column ion chromatography is used for the determination of HN 3 after neutralizing the rest acid in the sample with sodium hydroxide. Chromatography separation of HN 3 is carried out on a 25 cm x 0.46 cm (inside diameter) stainless steel column packed with Vydac IC302 ion Chromatography packing. The eluent is 1 mmol/L o-phthalic acid, and the ion is detected by conductivity detector. The detection limit in the presence chromatography is 5 μg/mL, the linear range is from 5 to 201 μg/mL, the linear correlation coefficient is 0.9994, respectively. The analysis accuracy is 2% for standard sample, and the detection limit is 51 μg/mL for HN 3 in the real sample. (authors)

  7. Single capture and transfer ionization in collisions of Clq+ projectile ions incident on helium

    International Nuclear Information System (INIS)

    Wong, K.L.; Ben-Itzhak, I.; Cocke, C.L.; Giese, J.P.; Richard, P.

    1995-01-01

    The Kansas State University linac has been used to measure the ratio of the cross sections for the processes of transfer ionization (TI) and single capture (SC) for 2 MeV/amu Cl q+ where q=7, 9, 13, 14, and 15 projectile ions incident on a helium target. The ratio was determined using a helium gas jet target by measuring coincidences between projectile-ion and recoil-ion final charge states. The σ TI /σ SC for Cl q+ were compared to measurements of bare F 9+ and hydrogenlike F 8+ and O 7+ taken at the same velocity. The ratios deviate from a q 2 scaling which is predicted in the perturbative regime. This deviation is attributed to screening by the projectile electrons for low q=7 and 9, and to the collision being non-perturbative for high q. A possible saturation effect in the ratio was observed for q similar 14. (orig.)

  8. The scattering of low energy helium ions and atoms from a copper single crystal, ch. 2

    International Nuclear Information System (INIS)

    Verheij, L.K.; Poelsema, B.; Boers, A.L.

    1976-01-01

    The scattering of 4-10 keV helium ions from a copper surface cannot be completely described with elastic, single collisions. The general behaviour of the measured energy and width of the surface peak can be explained by differences in inelastic energy losses for scattering from an ideal surface and from surface structures (damage). Multiple scattering effects have a minor influence. Additional information about the inelastic processes is obtained from scattering experiments with a primary atom beam. For large angles of incidence, the energy of the reflected ions is reduced about 20 eV if the primary beam consists of atoms instead of ions. An explanation of this effect and an explanation of the different behaviour of small angles is given. In the investigated energy range, the electronic stopping power might depend on the charge state of the primary particles. The experimental results are rather well explained by the Lindhard, Scharff, Schioett theory

  9. A linear ion optics model for extraction from a plasma ion source

    International Nuclear Information System (INIS)

    Dietrich, J.

    1987-01-01

    A linear ion optics model for ion extraction from a plasma ion source is presented, based on the paraxial equations which account for lens effects, space charge and finite source ion temperature. This model is applied to three- and four-electrode extraction systems with circular apertures. The results are compared with experimental data and numerical calculations in the literature. It is shown that the improved calculations of space charge effects and lens effects allow better agreement to be obtained than in earlier linear optics models. A principal result is that the model presented here describes the dependence of the optimum perveance on the aspect ratio in a manner similar to the nonlinear optics theory. (orig.)

  10. Numerical modelling of ion transport in flames

    KAUST Repository

    Han, Jie; Belhi, Memdouh; Bisetti, Fabrizio; Sarathy, Mani

    2015-01-01

    that changes in polarizability propagate with decreasing effect from binary transport coefficients to species number densities. We conclude that the chosen polarizability value has a limited effect on the ion distribution in freely propagating flames. We expect

  11. Sorption of Hg(II and Pb(II Ions on Chitosan-Iron(III from Aqueous Solutions: Single and Binary Systems

    Directory of Open Access Journals (Sweden)

    Byron Lapo

    2018-03-01

    Full Text Available The present work describes the study of mercury Hg(II and lead Pb(II removal in single and binary component systems into easily prepared chitosan-iron(III bio-composite beads. Scanning electron microscopy and energy-dispersive X-ray (SEM-EDX analysis, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA and point of zero charge (pHpzc analysis were carried out. The experimental set covered pH study, single and competitive equilibrium, kinetics, chloride and sulfate effects as well as sorption–desorption cycles. In single systems, the Langmuir nonlinear model fitted the experimental data better than the Freundlich and Sips equations. The sorbent material has more affinity to Hg(II rather than Pb(II ions, the maximum sorption capacities were 1.8 mmol·g−1 and 0.56 mmol·g−1 for Hg(II and Pb(II, respectively. The binary systems data were adjusted with competitive Langmuir isotherm model. The presence of sulfate ions in the multicomponent system [Hg(II-Pb(II] had a lesser impact on the sorption efficiency than did chloride ions, however, the presence of chloride ions improves the selectivity towards Hg(II ions. The bio-based material showed good recovery performance of metal ions along three sorption–desorption cycles.

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

    International Nuclear Information System (INIS)

    Leith, J.T.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Howard, J.

    1982-01-01

    The thoraco-lumbar (T12-L1) region of the spinal cord of rats was exposed to either single or fractionated (four daily exposures) doses of X rays (230 kVp) or heavy ions. The heavy ions used were carbon and neon, and the relative biological effectiveness (RBE) of both the plateau ionization region and the midpeak region of 4-cm spread-out Bragg peaks of each heavy ion were investigated. For single doses of carbon and neon ions in the plateau ionization region, RBE values of 1.45 +/- 0.25 (propagated 95% confidence limits) and 1.46 +/- 0.33, respectively, were obtained. In the spread peak regions for carbon and neon ions, the RBE values were 1.48 +/- 0.18 and 1.86 +/- 0.42, respectively. These values were obtained using the dose needed to produce 50% paralysis in a group of irradiated rats as the isoeffect comparison dose (ED 50 dose). Similarly, in groups of rats receiving four daily exposures, the RBE values for carbon and neon ions in the plateau ionization region were 1.31 +/- 0.27 and 1.80 +/- 0.24, respectively. In the spread peak regions of ionization for carbon and neon ions, the RBE values were 1.95 +/- 0.19 and 2.18 +/- 0.23, respectively. Similar values for RBE were obtained using changes in the activity of enzymes in spinal cord tissue (cyclic nucleotide phosphohydrolase and γ-glutamyl transpeptidase). Also, it was estimated that, for X irradiation, the fractional amount of dose repaired (at the ED 50 dose) was 0.64 +/- 0.10 (95% confidence limits). For carbon and neon ions in the plateau ionization region, the values for the fractional amount of dose repaired were 0.70 +/- 0.27 and 0.48 +/- 0.20, and for carbon and neon ions in the spread peak region of ionization, the fractional repair values were 0.40 +/- 0.10 and 0.52 +/- 0.17. Spinal cord tissue therefore shows a high capacity for subeffective damage repair

  13. Generalized Selectivity Description for Polymeric Ion-Selective Electrodes Based on the Phase Boundary Potential Model.

    Science.gov (United States)

    Bakker, Eric

    2010-02-15

    A generalized description of the response behavior of potentiometric polymer membrane ion-selective electrodes is presented on the basis of ion-exchange equilibrium considerations at the sample-membrane interface. This paper includes and extends on previously reported theoretical advances in a more compact yet more comprehensive form. Specifically, the phase boundary potential model is used to derive the origin of the Nernstian response behavior in a single expression, which is valid for a membrane containing any charge type and complex stoichiometry of ionophore and ion-exchanger. This forms the basis for a generalized expression of the selectivity coefficient, which may be used for the selectivity optimization of ion-selective membranes containing electrically charged and neutral ionophores of any desired stoichiometry. It is shown to reduce to expressions published previously for specialized cases, and may be effectively applied to problems relevant in modern potentiometry. The treatment is extended to mixed ion solutions, offering a comprehensive yet formally compact derivation of the response behavior of ion-selective electrodes to a mixture of ions of any desired charge. It is compared to predictions by the less accurate Nicolsky-Eisenman equation. The influence of ion fluxes or any form of electrochemical excitation is not considered here, but may be readily incorporated if an ion-exchange equilibrium at the interface may be assumed in these cases.

  14. The single-ion anisotropy effects in the mixed-spin ternary-alloy

    Science.gov (United States)

    Albayrak, Erhan

    2018-04-01

    The effect of single-ion anisotropy on the thermal properties of the ternary-alloy in the form of ABpC1-p is investigated on the Bethe lattice (BL) in terms of exact recursion relations. The simulation on the BL consists of placing A atoms (spin-1/2) on the odd shells and randomly placing B (spin-3/2) or C (spin-5/2) atoms with concentrations p and 1 - p, respectively, on the even shells. The phase diagrams are calculated in possible planes spanned by the system parameters: temperature, single-ion anisotropy, concentration and ratio of the bilinear interaction parameters for z = 3 corresponding to the honeycomb lattice. It is found that the crystal field drives the system to the lowest possible state therefore reducing the temperatures of the critical lines in agreement with the literature.

  15. Focused ion beam patterning to dielectrophoretically assemble single nanowire based devices

    International Nuclear Information System (INIS)

    La Ferrara, V; Massera, E; Francia, G Di; Alfano, B

    2010-01-01

    Direct-write processing is increasingly taking place in nanodevice fabrication. In this work, Focused Ion Beam (FIB), a powerful tool in maskless micromachining, is used for electrode patterning onto a silicon/silicon nitride substrate. Then a single palladium nanowire is assembled between electrodes by means of dielectrophoresis (DEP). The nanowire morphology depends on the electrode pattern when DEP conditions are fixed. FIB/DEP combination overcomes the problem of nanowire electrical contamination due to gallium ion bombardment and the as-grown nanowire retains its basic electrical properties. Single nanowire based devices have been fabricated with this novel approach and have been tested as hydrogen sensors, confirming the reliability of this technology.

  16. Ion-ion and ion-solvent interactions in lithium imidazolide electrolytes studied by Raman spectroscopy and DFT models.

    Science.gov (United States)

    Scheers, Johan; Niedzicki, Leszek; Zukowska, Grażyna Z; Johansson, Patrik; Wieczorek, Władysław; Jacobsson, Per

    2011-06-21

    Molecular level interactions are of crucial importance for the transport properties and overall performance of ion conducting electrolytes. In this work we explore ion-ion and ion-solvent interactions in liquid and solid polymer electrolytes of lithium 4,5-dicyano-(2-trifluoromethyl)imidazolide (LiTDI)-a promising salt for lithium battery applications-using Raman spectroscopy and density functional theory calculations. High concentrations of ion associates are found in LiTDI:acetonitrile electrolytes, the vibrational signatures of which are transferable to PEO-based LiTDI electrolytes. The origins of the spectroscopic changes are interpreted by comparing experimental spectra with simulated Raman spectra of model structures. Simple ion pair models in vacuum identify the imidazole nitrogen atom of the TDI anion to be the most important coordination site for Li(+), however, including implicit or explicit solvent effects lead to qualitative changes in the coordination geometry and improved correlation of experimental and simulated Raman spectra. To model larger aggregates, solvent effects are found to be crucial, and we finally suggest possible triplet and dimer ionic structures in the investigated electrolytes. In addition, the effects of introducing water into the electrolytes-via a hydrate form of LiTDI-are discussed.

  17. Phase diagrams of the ternary alloy with a single-ion anisotropy in the mean-field approximation

    International Nuclear Information System (INIS)

    Dely, J.; Bobak, A.

    2006-01-01

    The phase diagram of the AB p C 1-p ternary alloy consisting of Ising spins S A =32, S B =2, and S C =52 is investigated by the use of a mean-field theory based on the Bogoliubov inequality for the Gibbs free energy. The effect of the single-ion anisotropy on the phase diagrams is discussed by changing values of the parameters in the model Hamiltonian and comparison is made with the recently reported finite-temperature phase diagrams for the ternary alloy having spin S B =1

  18. Single and double electron capture in collisions of highly ionized, decelerated Ge ions with Ne

    International Nuclear Information System (INIS)

    Stoehlker, T.; Kozhuharov, C.; Mokler, P.H.; Olson, R.E.; Stachura, Z.; Warczak, A.

    1992-03-01

    Experimental cross-sections for non-radiative single and double electron capture from Ne target into H-like Ge ions at low intermediate collision energies (4-12) MeV/u are presented. The results are compared with theoretical calculations and an empirical scaling rule. Information concerning the impact parameter dependence of electron capture is extracted using classical trajectory Monte Carlo calculations. (orig.)

  19. Impact-parameter dependence of energy loss for 625-keV H+ ions in Si single crystals

    International Nuclear Information System (INIS)

    Dygo, A.; Boshart, M.A.; Seiberling, L.E.; Kabachnik, N.M.

    1994-01-01

    The energy distributions for 625-keV H + ions transmitted through thin Si single crystals are studied for detailed angular scans through the left-angle 110 right-angle and left-angle 100 right-angle axial as well as the {111} and {110} planar channels. Well-resolved structures in the distributions taken near the left-angle 110 right-angle axial direction are observed. The experimental energy-loss distributions are very well reproduced by a Monte Carlo simulation using the semiclassical approximation model for core electrons and the two-component free-electron-gas model for valence electrons. The best fit to the data is obtained if the model energy losses are scaled up for core electrons and down for valence electrons by several percent. The experimental distributions can also be reproduced by assuming the mean excitation energy for distant collisions of the ion with core electrons equal to 1.4 times the binding energy for a given shell. No significant differences between the distributions obtained using the solid-state and free-atom valence electron densities have been found. The evolution of the distributions for the left-angle 110 right-angle axial scan is discussed in terms of ion trajectories and the flux distribution. Also, the azimuthally averaged mean energy loss is studied as a function of tilt angle with respect to the left-angle 110 right-angle axis

  20. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

  1. Experimental study on heavy-ion single event effect on nanometer DDR SRAM

    International Nuclear Information System (INIS)

    Luo Yinhong; Zhang Fengqi; Guo Hongxia; Zhou Hui; Wang Yanping; Zhang Keying

    2013-01-01

    Single event effect experimental study on 90 nm and 65 nm DDR SRAM were carried out, single event upset (SEU) cross section was discussed as a function of several parameters such as feature size, test pattern, incidence angle, supply voltage. Key influence factors and effect rule were analyzed. Feasibility of the current test method was discussed. Results indicate that, SEU cross section reduces as technologies scale down; the influence of test pattern and power supply on SEU cross section is small; tilt angle increases SEU cross section due to multiple upset increasement. The applicability of cosine tilt test method is correlative to ion species and linear energy transfer (LET) values. (authors)

  2. Investigating change of properties in gallium ion irradiation patterned single-layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Dong, Jinyao; Bai, Bing [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Xie, Guoxin [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2016-10-14

    Besides its excellent physical properties, graphene promises to play a significant role in electronics with superior properties, which requires patterning of graphene for device integration. Here, we presented the changes in properties of single-layer graphene before and after patterning using gallium ion beam. Combined with Raman spectra of graphene, the scanning capacitance microscopy (SCM) image confirmed that a metal–insulator transition occurred after large doses of gallium ion irradiation. The changes in work function and Raman spectra of graphene indicated that the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. The patterning width of graphene presented an increasing trend due to the scattering influence of the impurities and the substrate. - Highlights: • The scanning capacitance microscopy image confirmed a metal–insulator transition occurred after large doses of gallium ion irradiation. • The changes indicated the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. • The patterning width of graphene presented a increasing trend due to the scattering influence of the impurities and the substrate.

  3. Single-crate stand-alone CAMAC control system for a negative ion source test facility

    International Nuclear Information System (INIS)

    Juras, R.C.; Ziegler, N.F.

    1979-01-01

    A single-crate CAMAC system was configured to control a negative ion source development facility at ORNL and control software was written for the crate microcomputer. The software uses inputs from a touch panel and a shaft encoder to control the various operating parameters of the test facility and uses the touch panel to display the operating status. Communication to and from the equipment at ion source potential is accomplished over optical fibers from an ORNL-built CAMAC module. A receiver at ion source potential stores the transmitted data and some of these stored values are then used to control discrete parameters of the ion source (i.e., power supply on or off). Other stored values are sent to a multiplexed digital-to-analog converter to provide analog control signals. A transmitter at ion source potential transmits discrete status information and several channels of analog data from an analog-to-digital converter back to the ground-potential receiver where it is stored to be read and displayed by the software

  4. Impact of temperature on single event upset measurement by heavy ions in SRAM devices

    International Nuclear Information System (INIS)

    Liu Tianqi; Geng Chao; Zhang Zhangang; Gu Song; Tong Teng; Xi Kai; Hou Mingdong; Liu Jie; Zhao Fazhan; Liu Gang; Han Zhengsheng

    2014-01-01

    The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12 C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209 Bi and 12 C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12 C ions but keep constant for 209 Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

  5. Quantitative occupational risk model: Single hazard

    International Nuclear Information System (INIS)

    Papazoglou, I.A.; Aneziris, O.N.; Bellamy, L.J.; Ale, B.J.M.; Oh, J.

    2017-01-01

    A model for the quantification of occupational risk of a worker exposed to a single hazard is presented. The model connects the working conditions and worker behaviour to the probability of an accident resulting into one of three types of consequence: recoverable injury, permanent injury and death. Working conditions and safety barriers in place to reduce the likelihood of an accident are included. Logical connections are modelled through an influence diagram. Quantification of the model is based on two sources of information: a) number of accidents observed over a period of time and b) assessment of exposure data of activities and working conditions over the same period of time and the same working population. Effectiveness of risk reducing measures affecting the working conditions, worker behaviour and/or safety barriers can be quantified through the effect of these measures on occupational risk. - Highlights: • Quantification of occupational risk from a single hazard. • Influence diagram connects working conditions, worker behaviour and safety barriers. • Necessary data include the number of accidents and the total exposure of worker • Effectiveness of risk reducing measures is quantified through the impact on the risk • An example illustrates the methodology.

  6. A 1D ion species model for an RF driven negative ion source

    Science.gov (United States)

    Turner, I.; Holmes, A. J. T.

    2017-08-01

    A one-dimensional model for an RF driven negative ion source has been developed based on an inductive discharge. The RF source differs from traditional filament and arc ion sources because there are no primary electrons present, and is simply composed of an antenna region (driver) and a main plasma discharge region. However the model does still make use of the classical plasma transport equations for particle energy and flow, which have previously worked well for modelling DC driven sources. The model has been developed primarily to model the Small Negative Ion Facility (SNIF) ion source at CCFE, but may be easily adapted to model other RF sources. Currently the model considers the hydrogen ion species, and provides a detailed description of the plasma parameters along the source axis, i.e. plasma temperature, density and potential, as well as current densities and species fluxes. The inputs to the model are currently the RF power, the magnetic filter field and the source gas pressure. Results from the model are presented and where possible compared to existing experimental data from SNIF, with varying RF power, source pressure.

  7. Quantum phase transitions in spin-1 X X Z chains with rhombic single-ion anisotropy

    Science.gov (United States)

    Ren, Jie; Wang, Yimin; You, Wen-Long

    2018-04-01

    We explore numerically the inverse participation ratios in the ground state of one-dimensional spin-1 X X Z chains with the rhombic single-ion anisotropy. By employing the techniques of density-matrix renormalization group, effects of the rhombic single-ion anisotropy on various information theoretical measures are investigated, such as the fidelity susceptibility, the quantum coherence, and the entanglement entropy. Their relations with the quantum phase transitions are also analyzed. The phase transitions from the Y -Néel phase to the large-Ex or the Haldane phase can be well characterized by the fidelity susceptibility. The second-order derivative of the ground-state energy indicates all the transitions are of second order. We also find that the quantum coherence, the entanglement entropy, the Schmidt gap, and the inverse participation ratios can be used to detect the critical points of quantum phase transitions. Results drawn from these quantum information observables agree well with each other. Finally we provide a ground-state phase diagram as functions of the exchange anisotropy Δ and the rhombic single-ion anisotropy E .

  8. Towards radiocarbon dating of single foraminifera with a gas ion source

    Science.gov (United States)

    Wacker, L.; Lippold, J.; Molnár, M.; Schulz, H.

    2013-01-01

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 μg for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO2 is liberated from 150 to 1150 μg of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO2 is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 μg (50 μg C) typically gives a 12C- ion source current of 10-15 μA over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 μg Cibicides pseudoungerianus test at 14,030 ± 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  9. Towards radiocarbon dating of single foraminifera with a gas ion source

    International Nuclear Information System (INIS)

    Wacker, L.; Lippold, J.; Molnár, M.; Schulz, H.

    2013-01-01

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 μg for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO 2 is liberated from 150 to 1150 μg of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO 2 is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 μg (50 μg C) typically gives a 12 C − ion source current of 10–15 μA over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 μg Cibicides pseudoungerianus test at 14,030 ± 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  10. Towards radiocarbon dating of single foraminifera with a gas ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, L., E-mail: wacker@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Lippold, J. [Heidelberg Academy of Sciences, 69120 Heidelberg (Germany); Molnar, M. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Schulz, H. [Institute for Geosciencies, University of Tuebingen, 72076 Tuebingen (Germany)

    2013-01-15

    Carbonate shells from foraminifera are often analysed for radiocarbon to determine the age of deep-sea sediments or to assess radiocarbon reservoir ages. However, a single foraminiferal test typically contains only a few micrograms of carbon, while most laboratories require more than 100 {mu}g for radiocarbon dating with an accelerator mass spectrometry (AMS) system. The collection of the required amount of foraminifera for a single analyses is therefore time consuming and not always possible. Here, we present a convenient method to measure the radiocarbon content of foraminifera using an AMS system fitted with a gas ion source. CO{sub 2} is liberated from 150 to 1150 {mu}g of carbonate in septum sealed vials by acid decomposition of the carbonate. The CO{sub 2} is collected on a zeolite trap and subsequently transferred to a syringe from where it is delivered to the ion source. A sample of 400 {mu}g (50 {mu}g C) typically gives a {sup 12}C{sup -} ion source current of 10-15 {mu}A over 20 min, yielding a measurement precision of less than 7 per mil for a modern sample. Using this method, we were able to date a single 560 {mu}g Cibicides pseudoungerianus test at 14,030 {+-} 160 radiocarbon years. Only a minor modification to our existing gas handling system was required and the system is fully automatable to further reduce the effort involved for sample preparation.

  11. Raman spectroscopy and single-photon source in an ion-cavity system

    International Nuclear Information System (INIS)

    Goncalves de Barros, H.

    2010-01-01

    The work presented in this thesis explores the interaction between a single trapped 40Ca+ ion and the electromagnetic field inside a high-finesse optical cavity. The coupling takes place via the use of a vacuum stimulated Raman transition, which transfers atomic population from the S1/2 to the D3/2 manifolds of the calcium ion producing a photon in the cavity. This photon is measured and properties of the system are evaluated. Spectroscopy measurements of the Raman transitions are performed and all possible transitions are identified for different polarizations of both drive laser and cavity fields. The system is also used to deterministically produce single photons. Simulation curves quantitatively match the experimental results within calibration error bars. The single-photon creation efficiency obtained in this work overcomes previous ion-cavity setups and is comparable to state-of-the-art systems composed of a neutral atom and a cavity operating in the strong coupling regime. (author)

  12. Modeling the ion transfer and polarization of ion exchange membranes in bioelectrochemical systems.

    Science.gov (United States)

    Harnisch, Falk; Warmbier, Robert; Schneider, Ralf; Schröder, Uwe

    2009-06-01

    An explicit numerical model for the charge balancing ion transfer across monopolar ion exchange membranes under conditions of bioelectrochemical systems is presented. Diffusion and migration equations have been solved according to the Nernst-Planck Equation and the resulting ion concentrations, pH values and the resistance values of the membrane for different conditions were computed. The modeling results underline the principle limitations of the application of ion exchange membranes in biological fuel cells and electrolyzers, caused by the inherent occurrence of a pH-gradient between anode and cathode compartment, and an increased ohmic membrane resistance at decreasing electrolyte concentrations. Finally, the physical and numerical limitations of the model are discussed.

  13. Use of heavy ions to model radiation damage of metals

    International Nuclear Information System (INIS)

    Shirokov, S.V.; Vyshemirskij, M.P.

    2011-01-01

    The methods for modeling radiation damage of metals using heavy ions are reviewed and the results obtained are analyzed. It is shown that irradiation of metals with heavy ion can simulate neutron exposure with the equivalent dose with adequate accuracy and permits a detailed analysis of radiation damage of metals

  14. Numerical model of electron cyclotron resonance ion source

    Directory of Open Access Journals (Sweden)

    V. Mironov

    2015-12-01

    Full Text Available Important features of the electron cyclotron resonance ion source (ECRIS operation are accurately reproduced with a numerical code. The code uses the particle-in-cell technique to model the dynamics of ions in ECRIS plasma. It is shown that a gas dynamical ion confinement mechanism is sufficient to provide the ion production rates in ECRIS close to the experimentally observed values. Extracted ion currents are calculated and compared to the experiment for a few sources. Changes in the simulated extracted ion currents are obtained with varying the gas flow into the source chamber and the microwave power. Empirical scaling laws for ECRIS design are studied and the underlying physical effects are discussed.

  15. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    International Nuclear Information System (INIS)

    Walker, D.D.

    1999-01-01

    Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R. G. Anthony, Department of Chemical Engineering, Texas A ampersand 038;M University, and Professor S. W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports

  16. 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

  17. Modelling transport in single electron transistor

    International Nuclear Information System (INIS)

    Dinh Sy Hien; Huynh Lam Thu Thao; Le Hoang Minh

    2009-01-01

    We introduce a model of single electron transistor (SET). Simulation programme of SET is used as the exploratory tool in order to gain better understanding of process and device physics. This simulator includes a graphic user interface (GUI) in Matlab. The SET was simulated using GUI in Matlab to get current-voltage (I-V) characteristics. In addition, effects of device capacitance, bias, temperature on the I-V characteristics were obtained. In this work, we review the capabilities of the simulator of the SET. Typical simulations of the obtained I-V characteristics of the SET are presented.

  18. Infrared laser dissociation of single megadalton polymer ions in a gated electrostatic ion trap: the added value of statistical analysis of individual events.

    Science.gov (United States)

    Halim, Mohammad A; Clavier, Christian; Dagany, Xavier; Kerleroux, Michel; Dugourd, Philippe; Dunbar, Robert C; Antoine, Rodolphe

    2018-05-07

    In this study, we report the unimolecular dissociation mechanism of megadalton SO 3 -containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) polymer cations and anions with the aid of infrared multiphoton dissociation coupled to charge detection ion trap mass spectrometry. A gated electrostatic ion trap ("Benner trap") is used to store and detect single gaseous polymer ions generated by positive and negative polarity in an electrospray ionization source. The trapped ions are then fragmented due to the sequential absorption of multiple infrared photons produced from a continuous-wave CO 2 laser. Several fragmentation pathways having distinct signatures are observed. Highly charged parent ions characteristically adopt a distinctive "stair-case" pattern (assigned to the "fission" process) whereas low charge species take on a "funnel like" shape (assigned to the "evaporation" process). Also, the log-log plot of the dissociation rate constants as a function of laser intensity between PAMPS positive and negative ions is significantly different.

  19. Dielectronic recombination experiments with tungsten ions at the test storage ring and development of a single-particle detector at the cryogenic storage ring

    International Nuclear Information System (INIS)

    Spruck, Kaija

    2015-05-01

    This work is about electron-ion collision experiments at the ion storage rings of the Max Planck Institute for Nuclear Physics in Heidelberg. Absolute recombination rate coefficients of highly-charged tungsten ions featuring an open 4-f-shell structure have been measured at the heavy-ion storage ring TSR. The resulting plasma rate coefficients have been used to probe the significance of newly developed theoretical approaches. Plasma rate coefficients of highly-charged tungsten ions are in particular interesting for the development of plasma models for nuclear fusion reactors, since tungsten is a foreseeable impurity in the fusion plasma. In the relevant temperature range, the experimental results exceed the theoretical data used so far by up to a factor of 10, showing the need for more reliable theoretical calculations. Furthermore, based on the design of the detectors which have been used in the experiments at TSR, a movable single-particle detector for electron-ion recombination studies at the cryogenic storage ring CSR has been developed and installed within the scope of this work. The device has been designed specifically to meet the requirements of the CSR regarding low ion energies and cryogenic ambient temperature conditions. In a series of experiments, the detector was carefully characterised and successfully tested for its compatibility with these requirements. The detector was part of the infrastructure used for the room-temperature commissioning of CSR (2014) and is currently operated as a single-particle counter during the first cryogenic operation of CSR in 2015.

  20. Dielectronic recombination experiments with tungsten ions at the test storage ring and development of a single-particle detector at the cryogenic storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Spruck, Kaija

    2015-05-15

    This work is about electron-ion collision experiments at the ion storage rings of the Max Planck Institute for Nuclear Physics in Heidelberg. Absolute recombination rate coefficients of highly-charged tungsten ions featuring an open 4-f-shell structure have been measured at the heavy-ion storage ring TSR. The resulting plasma rate coefficients have been used to probe the significance of newly developed theoretical approaches. Plasma rate coefficients of highly-charged tungsten ions are in particular interesting for the development of plasma models for nuclear fusion reactors, since tungsten is a foreseeable impurity in the fusion plasma. In the relevant temperature range, the experimental results exceed the theoretical data used so far by up to a factor of 10, showing the need for more reliable theoretical calculations. Furthermore, based on the design of the detectors which have been used in the experiments at TSR, a movable single-particle detector for electron-ion recombination studies at the cryogenic storage ring CSR has been developed and installed within the scope of this work. The device has been designed specifically to meet the requirements of the CSR regarding low ion energies and cryogenic ambient temperature conditions. In a series of experiments, the detector was carefully characterised and successfully tested for its compatibility with these requirements. The detector was part of the infrastructure used for the room-temperature commissioning of CSR (2014) and is currently operated as a single-particle counter during the first cryogenic operation of CSR in 2015.

  1. Fluorescence-based high-throughput functional profiling of ligand-gated ion channels at the level of single cells.

    Directory of Open Access Journals (Sweden)

    Sahil Talwar

    Full Text Available Ion channels are involved in many physiological processes and are attractive targets for therapeutic intervention. Their functional properties vary according to their subunit composition, which in turn varies in a developmental and tissue-specific manner and as a consequence of pathophysiological events. Understanding this diversity requires functional analysis of ion channel properties in large numbers of individual cells. Functional characterisation of ligand-gated channels involves quantitating agonist and drug dose-response relationships using electrophysiological or fluorescence-based techniques. Electrophysiology is limited by low throughput and high-throughput fluorescence-based functional evaluation generally does not enable the characterization of the functional properties of each individual cell. Here we describe a fluorescence-based assay that characterizes functional channel properties at single cell resolution in high throughput mode. It is based on progressive receptor activation and iterative fluorescence imaging and delivers >100 dose-responses in a single well of a 384-well plate, using α1-3 homomeric and αβ heteromeric glycine receptor (GlyR chloride channels as a model system. We applied this assay with transiently transfected HEK293 cells co-expressing halide-sensitive yellow fluorescent protein and different GlyR subunit combinations. Glycine EC50 values of different GlyR isoforms were highly correlated with published electrophysiological data and confirm previously reported pharmacological profiles for the GlyR inhibitors, picrotoxin, strychnine and lindane. We show that inter and intra well variability is low and that clustering of functional phenotypes permits identification of drugs with subunit-specific pharmacological profiles. As this method dramatically improves the efficiency with which ion channel populations can be characterized in the context of cellular heterogeneity, it should facilitate systems

  2. Single toxin dose-response models revisited

    Energy Technology Data Exchange (ETDEWEB)

    Demidenko, Eugene, E-mail: eugened@dartmouth.edu [Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, NH03756 (United States); Glaholt, SP, E-mail: sglaholt@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States); Kyker-Snowman, E, E-mail: ek2002@wildcats.unh.edu [Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH03824 (United States); Shaw, JR, E-mail: joeshaw@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Chen, CY, E-mail: Celia.Y.Chen@dartmouth.edu [Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States)

    2017-01-01

    The goal of this paper is to offer a rigorous analysis of the sigmoid shape single toxin dose-response relationship. The toxin efficacy function is introduced and four special points, including maximum toxin efficacy and inflection points, on the dose-response curve are defined. The special points define three phases of the toxin effect on mortality: (1) toxin concentrations smaller than the first inflection point or (2) larger then the second inflection point imply low mortality rate, and (3) concentrations between the first and the second inflection points imply high mortality rate. Probabilistic interpretation and mathematical analysis for each of the four models, Hill, logit, probit, and Weibull is provided. Two general model extensions are introduced: (1) the multi-target hit model that accounts for the existence of several vital receptors affected by the toxin, and (2) model with a nonzero mortality at zero concentration to account for natural mortality. Special attention is given to statistical estimation in the framework of the generalized linear model with the binomial dependent variable as the mortality count in each experiment, contrary to the widespread nonlinear regression treating the mortality rate as continuous variable. The models are illustrated using standard EPA Daphnia acute (48 h) toxicity tests with mortality as a function of NiCl or CuSO{sub 4} toxin. - Highlights: • The paper offers a rigorous study of a sigmoid dose-response relationship. • The concentration with highest mortality rate is rigorously defined. • A table with four special points for five morality curves is presented. • Two new sigmoid dose-response models have been introduced. • The generalized linear model is advocated for estimation of sigmoid dose-response relationship.

  3. Some remarks on the statistical model of heavy ion collisions

    International Nuclear Information System (INIS)

    Koch, V.

    2003-01-01

    This contribution is an attempt to assess what can be learned from the remarkable success of this statistical model in describing ratios of particle abundances in ultra-relativistic heavy ion collisions

  4. The accuracy of heavy ion optical model calculations

    International Nuclear Information System (INIS)

    Kozik, T.

    1980-01-01

    There is investigated in detail the sources and magnitude of numerical errors in heavy ion optical model calculations. It is shown on example of 20 Ne + 24 Mg scattering at Esub(LAB)=100 MeV. (author)

  5. Experimental study of single-electron loss by Ar+ ions in rare-gas atoms

    Science.gov (United States)

    Reyes, P. G.; Castillo, F.; Martínez, H.

    2001-04-01

    Absolute differential and total cross sections for single-electron loss were measured for Ar+ ions on rare-gas atoms in the laboratory energy range of 1.5 to 5.0 keV. The electron loss cross sections for all the targets studied are found to be in the order of magnitude between 10-19 and 10-22 cm2, and show a monotonically increasing behaviour as a function of the incident energy. The behaviour of the total single-electron loss cross sections with the atomic target number, Zt, shows different dependences as the collision energy increases. In all cases the present results display experimental evidence of saturation in the single-electron loss cross section as the atomic number of the target increases.

  6. Experimental determination of electron shock excitation cross sections for a singly charged gadolinium ion

    International Nuclear Information System (INIS)

    Smirnov, Yu.M.

    1995-01-01

    The trends observed in the processes of excitation with simultaneous ionization have received little study. This is particularly so for rare-earth elements having electron shells of complex structure and optical spectra very rich in lines. Among the basic factors responsible for such a situation, we should mention two: the difficulty presented by theoretical analysis of the processes discussed and the absence of factual information about the excitation cross sections with simultaneous ionization for the majority of rare-earth elements. The aim of the present work is to investigate the excitation of a singly charged gadolinium ion in the collisions of monokinetic electrons with gadolinium atoms. Up to the present time, only the excitation cross sections of a gadolinium atom have been measured, where investigation of the electron shock excitation of gadolinium atoms in their free state is associated with overcoming large experimental difficulties. About 160 crosss sections for the excitation of a singly charged gadolinium ion were measured and for a third of the cross sections; the energy dependences were recorded for the change in energy of the elecrons from the excitation threshold up to 200 eV. Included are tables of the wavelength, transistion, internal quantum number, the energy of the lowere and upper levels, and the values of cross sections for the charged gadolinium ion. Diagrams of the transistion energy states of Gd (II) and spectroscopy are presented and explained

  7. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Hun

    1996-02-15

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10{sup -7} m {center_dot} rad and 7.87 x 10{sup -9}A {center_dot} V{sup -3/2}, respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics.

  8. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    International Nuclear Information System (INIS)

    Kim, Su Hun

    1996-02-01

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10 -7 m · rad and 7.87 x 10 -9 A · V -3/2 , respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics

  9. Trapped-ion anomalous diffusion coefficient on the basis of single mode saturation

    International Nuclear Information System (INIS)

    Koshi, Yuji; Hatayama, Akiyoshi; Ogasawara, Masatada.

    1982-03-01

    Expressions of the anomalous diffusion coefficient due to the dissipative trapped ion instability (DTII) are derived for the case with and without the effect of magnetic shear. Derivation is made by taking into account of the single mode saturation of the DTII previously obtained numerically. In the absence of the shear effect, the diffusion coefficient is proportional to #betta#sub(i)a 2 (#betta#sub(i) is the effective collision frequency of the trapped ions and a is the minor radius of a torus) and is much larger than the neoclassical ion heat conductivity. In the presence of the shear effect, the diffusion coefficient is much smaller than the Kadomtsev and Pogutse's value and is the same order of magnitude as the neoclassical ion heat conductivity. Dependences of the diffusion coefficient on the temperature and on the total particle number density are rather complicated due to the additional spectral cut-off, which is introduced to regularize the short wavelength modes in the numerical analysis. (author)

  10. Steady-State Ion Beam Modeling with MICHELLE

    Science.gov (United States)

    Petillo, John

    2003-10-01

    There is a need to efficiently model ion beam physics for ion implantation, chemical vapor deposition, and ion thrusters. Common to all is the need for three-dimensional (3D) simulation of volumetric ion sources, ion acceleration, and optics, with the ability to model charge exchange of the ion beam with a background neutral gas. The two pieces of physics stand out as significant are the modeling of the volumetric source and charge exchange. In the MICHELLE code, the method for modeling the plasma sheath in ion sources assumes that the electron distribution function is a Maxwellian function of electrostatic potential over electron temperature. Charge exchange is the process by which a neutral background gas with a "fast" charged particle streaming through exchanges its electron with the charged particle. An efficient method for capturing this is essential, and the model presented is based on semi-empirical collision cross section functions. This appears to be the first steady-state 3D algorithm of its type to contain multiple generations of charge exchange, work with multiple species and multiple charge state beam/source particles simultaneously, take into account the self-consistent space charge effects, and track the subsequent fast neutral particles. The solution used by MICHELLE is to combine finite element analysis with particle-in-cell (PIC) methods. The basic physics model is based on the equilibrium steady-state application of the electrostatic particle-in-cell (PIC) approximation employing a conformal computational mesh. The foundation stems from the same basic model introduced in codes such as EGUN. Here, Poisson's equation is used to self-consistently include the effects of space charge on the fields, and the relativistic Lorentz equation is used to integrate the particle trajectories through those fields. The presentation will consider the complexity of modeling ion thrusters.

  11. Ion Density Analysis of Single-Stranded DNA in Liquid Crystal

    Science.gov (United States)

    Iwabata, Kazuki; Seki, Yasutaka; Toizumi, Ryota; Shimada, Yuki; Furue, Hirokazu; Sakaguchi, Kengo

    2013-09-01

    With the widespread use of liquid crystals (LCs) in liquid crystal displays, we have looked into the application of liquid crystals in biotechnology. The purpose of the study described here is to investigate the physical properties of DNA using LCs. Synthetic oligonucleotide molecules were dispersed in MLC6884, the sample injected into antiparallel cells, and the amount of mobile ions was measured. The LC cell doped with oligonucleotide molecules showed a sequence-dependent, specific correlation between oligonucleotide concentration and the amount of mobile ions in the LC cells. In the framework of the Stokes model and polyacrylamide gel electrophoresis (PAGE) analysis, we speculate that this result arises from the difference in ion mobility, which is caused by the shape of the oligonucleotide molecule in the LC.

  12. Propensity rules for orientation in singly-charged ion-atom collisions

    International Nuclear Information System (INIS)

    Nielsen, S.E.; Dubois, A.; Hansen, J.P.

    1990-01-01

    Orientation effects for electron capture and excitation in singly-charged ion-atom collisions are analysed using the atomic basis impact parameter method with full inclusion of electron translational factors. We find that the orientation preferences previously predicted for excitation in terms of propensity rules may still be observed when capture is present in ion-atom collisions. Furthermore, in spite of intricate behaviour of the direct capture couplings during the collision, we draw some parallel conclusions for the orientation of the capture states. We illustrate these perturbative predictions by close-coupling calculations for H + -Na(3s) collisions where clear propensity for orientation of the H(2p) capture state is demonstrated in impact parameter and velocity dependences. Finally we predict pronounced orientation effects for H(2s) and H(2p) capture in collisions of H + with initially oriented Na(3p) states. (author)

  13. Quantum sensing of the phase-space-displacement parameters using a single trapped ion

    Science.gov (United States)

    Ivanov, Peter A.; Vitanov, Nikolay V.

    2018-03-01

    We introduce a quantum sensing protocol for detecting the parameters characterizing the phase-space displacement by using a single trapped ion as a quantum probe. We show that, thanks to the laser-induced coupling between the ion's internal states and the motion mode, the estimation of the two conjugated parameters describing the displacement can be efficiently performed by a set of measurements of the atomic state populations. Furthermore, we introduce a three-parameter protocol capable of detecting the magnitude, the transverse direction, and the phase of the displacement. We characterize the uncertainty of the two- and three-parameter problems in terms of the Fisher information and show that state projective measurement saturates the fundamental quantum Cramér-Rao bound.

  14. Raman spectroscopic investigations of swift heavy ion irradiation effects in single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Olejniczak, A.; Skuratov, V.A.; Lukaszewicz, J.P.

    2013-01-01

    In this study, we report the results on swift heavy ion irradiation effects in single-walled carbon nanotubes (SWNTs). Buckypapers, prepared of CVD grown, SWNTs were irradiated at room temperature with 167 MeV Xe ions to fluences in the range of 6×10 11 - 6.5×10 13 cm -2 and investigated using Raman spectroscopy. We observed a rich set of features in the intermediate frequency mode region. Some of them, being defect-induced, resembled fairly well the phonon density of states (DOS) of nanocrystalline glassy carbon. Analysis of the RBM modes has shown that the broader metallic tubes are characterized by higher radiation stability than thinner semiconducting ones. (authors)

  15. Ion feedback suppression using inclined MCP holes in a 'single-MCP+micromegas+pads' detector

    International Nuclear Information System (INIS)

    Va'vra, J.; Sumiyoshi, T.

    2005-01-01

    We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in the presence of a magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (microchannel plate), a micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

  16. Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

    DEFF Research Database (Denmark)

    Henriksen, L.; Johansen, A.; Koch, J.

    1968-01-01

    Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

  17. An efficient single-step scheme for manipulating quantum information of two trapped ions beyond the Lamb-Dicke limit

    International Nuclear Information System (INIS)

    Wei, L.F.; Nori, Franco

    2003-01-01

    Based on the exact conditional quantum dynamics for a two-ion system, we propose an efficient single-step scheme for coherently manipulating quantum information of two trapped cold ions by using a pair of synchronous laser pulses. Neither the auxiliary atomic level nor the Lamb-Dicke approximation are needed

  18. Swift heavy ion induced single event upsets in high density UV-EPROM's

    Energy Technology Data Exchange (ETDEWEB)

    Dahiwale, S.S. [Department of Physics, University of Pune, Pune 7 (India); Shinde, N.S. [Department of Chemical Engineering, Mie University (Japan); Kanjilal, D. [Inter University Accelerator Center, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 7 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 7 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-04-15

    A few high density UV-EPROM's (32Kb x 8) were irradiated with 5.41 MeV energy {alpha}-particles with fluences from 10{sup 4} to 10{sup 8} alphas/cm{sup 2} and 100 MeV nickel, iodine and silver ions for low fluences between 5 x 10{sup 7} and 10{sup 8} ions/cm{sup 2}. The energy and ion species was selected on the basis of predicted threshold values of linear energy transfer (LET) in silicon. The program which was stored in the memory found to be changed from 0 to 1 and 1 to 0 state, respectively. On the basis of changed states, the cross-sections ({sigma}) were calculated to investigate the single event effects/upsets. No upset was observed in case of {alpha}-particle since it has very low LET, but the SEU cross-section found to be more in case of Iodine i.e. 2.29 x 10{sup -3} cm{sup 2} than that of nickel, 2.12 x 10{sup -3} cm{sup 2} and silver, 2.26 x 10{sup -3}. This mainly attributes that LET for iodine is more as compared to silver and nickel ions, which deposits large amount of energy near the sensitive node of memory cell in the form of electron-hole pairs required to change the state. These measured SEU cross-section were also compared with theoretically predicted values along with the Weibull distribution fit to the ion induced experimental SEU data. The theoretical predicted SEU cross-section 3.27 x 10{sup -3} cm{sup 2} found to be in good agreement with the measured SEU cross-section.

  19. Molecular dynamics simulations to examine structure, energetics, and evaporation/condensation dynamics in small charged clusters of water or methanol containing a single monatomic ion.

    Science.gov (United States)

    Daub, Christopher D; Cann, Natalie M

    2012-11-01

    We study small clusters of water or methanol containing a single Ca(2+), Na(+), or Cl(-) ion with classical molecular dynamics simulations, using models that incorporate polarizability via the Drude oscillator framework. Evaporation and condensation of solvent from these clusters is examined in two systems, (1) for isolated clusters initially prepared at different temperatures and (2) those with a surrounding inert (Ar) gas of varying temperature. We examine these clusters over a range of sizes, from almost bare ions up to 40 solvent molecules. We report data on the evaporation and condensation of solvent from the clusters and argue that the observed temperature dependence of evaporation in the smallest clusters demonstrates that the presence of heated gas alone cannot, in most cases, solely account for bare ion production in electrospray ionization (ESI), neglecting the key contribution of the electric field. We also present our findings on the structure and energetics of the clusters as a function of size. Our data agree well with the abundant literature on hydrated ion clusters and offer some novel insight into the structure of methanol and ion clusters, especially those with a Cl(-) anion, where we observe the presence of chain-like structures of methanol molecules. Finally, we provide some data on the reparameterizations necessary to simulate ions in methanol using the separately developed Drude oscillator models for methanol and for ions in water.

  20. Generalized reduced fluid model with finite ion-gyroradius effects

    International Nuclear Information System (INIS)

    Hsu, C.T.; Hazeltine, R.D.; Morrison, P.J.

    1985-04-01

    Reduced fluid models have become important tools for studying the nonlinear dynamics of plasma in a large aspect-ratio tokamak. A self-consistent nonlinear reduced fluid model, with finite ion-gyroradius effects is presented. The model is distinctive in allowing for arbitrary beta and in satisfying an exact, relatively simple energy conservation law

  1. Electrical characterization of single cells using polysilicon wire ion sensor in an isolation window.

    Science.gov (United States)

    Wu, You-Lin; Hsu, Po-Yen; Hsu, Chung-Ping; Wang, Chih-Cheng; Lee, Li-Wen; Lin, Jing-Jenn

    2011-10-01

    A polysilicon wire (PSW) sensor can detect the H(+) ion density (pH value) of the medium coated on its surface, and different cells produce different extracellular acidification and hence different H(+) ion densities. Based on this, we used a PSW sensor in combination with a mold-cast polydimethylsiloxane (PDMS) isolation window to detect the adhesion, apoptosis and extracellular acidification of single normal cells and single cancer cells. Single living human normal cells WI38, MRC5, and BEAS-2B as well as non-small-cell lung cancer (NSCLC) cells A549, H1299, and CH27 were cultivated separately inside the isolation window. The current flowing through the PSW channel was measured. From the PSW channel current change as a function of time, we determined the cell adhesion time by observing the time required for the current change to saturate, since a stable extracellular ion density was established after the cells were completely adhered to the PSW surface. The apoptosis of cells can also be determined when the channel current change drops to zero. We found that all the NSCLC cells had a higher channel current change and hence a lower pH value than the normal cells anytime after they were seeded. The corresponding average pH values were 5.86 for A549, 6.00 for H1299, 6.20 for CH27, 6.90 for BEAS-2B, 6.96for MRC5, and 7.02 for WI38, respectively, after the cells were completely adhered to the PSW surface. Our results show that NSCLC cells have a stronger cell-substrate adhesion and a higher extracellular acidification rate than normal cells.

  2. Subattoampere current induced by single ions in silicon oxide layers of nonvolatile memory cells

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Larcher, L.; Visconti, A.; Bonanomi, M.

    2006-01-01

    A single ion impinging on a thin silicon dioxide layer generates a number of electron/hole pairs proportional to its linear energy transfer coefficient. Defects generated by recombination can act as a conductive path for electrons that cross the oxide barrier, thanks to a multitrap-assisted mechanism. We present data on the dependence of this phenomenon on the oxide thickness by using floating gate memory arrays. The tiny number of excess electrons stored in these devices allows for extremely high sensitivity, impossible with any direct measurement of oxide leakage current. Results are of particular interest for next generation devices

  3. Effects of ion beam heating on Raman spectra of single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Hulman, Martin; Skakalova, Viera; Krasheninnikov, A. V.; Roth, S.

    2009-01-01

    Free standing films of single-wall carbon nanotubes were irradiated with energetic N + and C 4+ ions. The observed changes in the Raman line shape of the radial breathing mode and the G band of the C 4+ irradiated samples were similar to those found for a thermally annealed sample. We ascribe these changes to thermal desorption of volatile dopants from the initially doped nanotubes. A simple geometry of the experiment allows us to estimate the temperature rise by one-dimensional heat conductance equation. The calculation indicates that irradiation-mediated increase in temperature may account for the observed Raman spectra changes

  4. Quantum Heisenberg antiferromagnetic chains with exchange and single-ion anisotropies

    International Nuclear Information System (INIS)

    Peters, D; Selke, W; McCulloch, I P

    2010-01-01

    Using density matrix renormalization group calculations, ground state properties of the spin-1 Heisenberg chain with exchange and quadratic single-ion anisotropies in an external field are studied, for special choices of the two kinds of anisotropies. In particular, the phase diagram includes antiferromagnetic, spin-liquid (or spin-flop), IS2, and supersolid (or biconical) phases. Especially, new features of the spin-liquid and supersolid phases are discussed. Properties of the quantum chains are compared to those of corresponding classical spin chains.

  5. Thermal modeling of cylindrical lithium ion battery during discharge cycle

    International Nuclear Information System (INIS)

    Jeon, Dong Hyup; Baek, Seung Man

    2011-01-01

    Highlights: → Transient and thermo-electric finite element analysis (FEA) of cylindrical lithium ion (Li-ion) battery was presented. → This model provides the thermal behavior of Li-ion battery during discharge cycle. → A LiCoO 2 /C battery at various discharge rates was investigated. → The contribution of heat source due to joule heating was significant at a high discharge rate. → The contribution of heat source due to entropy change was dominant at a low discharge rate. - Abstract: Transient and thermo-electric finite element analysis (FEA) of cylindrical lithium ion (Li-ion) battery was presented. The simplified model by adopting a cylindrical coordinate was employed. This model provides the thermal behavior of Li-ion battery during discharge cycle. The mathematical model solves conservation of energy considering heat generations due to both joule heating and entropy change. A LiCoO 2 /C battery at various discharge rates was investigated. The temperature profile from simulation had similar tendency with experiment. The temperature profile was decomposed with contributions of each heat sources and was presented at several discharge rates. It was found that the contribution of heat source due to joule heating was significant at a high discharge rate, whereas that due to entropy change was dominant at a low discharge rate. Also the effect of cooling condition and the LiNiCoMnO 2 /C battery were analyzed for the purpose of temperature reduction.

  6. Atomistic modeling of ion beam induced amorphization in silicon

    International Nuclear Information System (INIS)

    Pelaz, Lourdes; Marques, Luis A.; Lopez, Pedro; Santos, Ivan; Aboy, Maria; Barbolla, Juan

    2005-01-01

    Ion beam induced amorphization in Si has attracted significant interest since the beginning of the use of ion implantation for the fabrication of Si devices. Nowadays, a renewed interest in the modeling of amorphization mechanisms at atomic level has arisen due to the use of preamorphizing implants and high dopant implantation doses for the fabrication of nanometric-scale Si devices. In this work, we briefly describe the existing phenomenological and defect-based amorphization models. We focus on the atomistic model we have developed to describe ion beam induced amorphization in Si. In our model, the building block for the amorphous phase is the bond defect or IV pair, whose stability increases with the number of surrounding IV pairs. This feature explains the regrowth behavior of different damage topologies and the kinetics of the crystalline to amorphous transition. The model provides excellent quantitative agreement with experimental results

  7. Complex versus simple models: ion-channel cardiac toxicity prediction.

    Science.gov (United States)

    Mistry, Hitesh B

    2018-01-01

    There is growing interest in applying detailed mathematical models of the heart for ion-channel related cardiac toxicity prediction. However, a debate as to whether such complex models are required exists. Here an assessment in the predictive performance between two established large-scale biophysical cardiac models and a simple linear model B net was conducted. Three ion-channel data-sets were extracted from literature. Each compound was designated a cardiac risk category using two different classification schemes based on information within CredibleMeds. The predictive performance of each model within each data-set for each classification scheme was assessed via a leave-one-out cross validation. Overall the B net model performed equally as well as the leading cardiac models in two of the data-sets and outperformed both cardiac models on the latest. These results highlight the importance of benchmarking complex versus simple models but also encourage the development of simple models.

  8. Complex versus simple models: ion-channel cardiac toxicity prediction

    Directory of Open Access Journals (Sweden)

    Hitesh B. Mistry

    2018-02-01

    Full Text Available There is growing interest in applying detailed mathematical models of the heart for ion-channel related cardiac toxicity prediction. However, a debate as to whether such complex models are required exists. Here an assessment in the predictive performance between two established large-scale biophysical cardiac models and a simple linear model Bnet was conducted. Three ion-channel data-sets were extracted from literature. Each compound was designated a cardiac risk category using two different classification schemes based on information within CredibleMeds. The predictive performance of each model within each data-set for each classification scheme was assessed via a leave-one-out cross validation. Overall the Bnet model performed equally as well as the leading cardiac models in two of the data-sets and outperformed both cardiac models on the latest. These results highlight the importance of benchmarking complex versus simple models but also encourage the development of simple models.

  9. Polarization bremsstrahlung of a hydrogen-like ion in a single crystal

    International Nuclear Information System (INIS)

    Astapenko, V. A.

    2009-01-01

    Polarization bremsstrahlung (PB) that arises when a fast hydrogen-like ion is scattered in a single crystal is investigated theoretically. Four types of the process are analyzed that are caused by virtual excitation of electrons of the target and of the incident particle (IP), as well as by a coherent and incoherent interaction between the IP and the single crystal. The spectral, angular, and velocity (of the IP) characteristics of PB are calculated with regard to the spectral function of a photodetector. Optimal observation conditions and regions in which different types of PB are dominant are determined, and the dependence of these regions on the charge of the IP nucleus and of the target atoms is revealed

  10. High-fidelity state detection and tomography of a single-ion Zeeman qubit

    International Nuclear Information System (INIS)

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

    2011-01-01

    We demonstrate high-fidelity Zeeman qubit state detection in a single trapped 88 Sr + ion. Qubit readout is performed by shelving one of the qubit states to a metastable level using a narrow linewidth diode laser at 674 nm, followed by state-selective fluorescence detection. The average fidelity reached for the readout of the qubit state is 0.9989(1). We then measure the fidelity of state tomography, averaged over all possible single-qubit states, which is 0.9979(2). We also fully characterize the detection process using quantum process tomography. This readout fidelity is compatible with recent estimates of the detection error threshold required for fault-tolerant computation, whereas high-fidelity state tomography opens the way for high-precision quantum process tomography.

  11. High-fidelity state detection and tomography of a single-ion Zeeman qubit

    Energy Technology Data Exchange (ETDEWEB)

    Keselman, A; Glickman, Y; Akerman, N; Kotler, S; Ozeri, R, E-mail: ozeri@weizmann.ac.il [Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2011-07-15

    We demonstrate high-fidelity Zeeman qubit state detection in a single trapped {sup 88}Sr{sup +} ion. Qubit readout is performed by shelving one of the qubit states to a metastable level using a narrow linewidth diode laser at 674 nm, followed by state-selective fluorescence detection. The average fidelity reached for the readout of the qubit state is 0.9989(1). We then measure the fidelity of state tomography, averaged over all possible single-qubit states, which is 0.9979(2). We also fully characterize the detection process using quantum process tomography. This readout fidelity is compatible with recent estimates of the detection error threshold required for fault-tolerant computation, whereas high-fidelity state tomography opens the way for high-precision quantum process tomography.

  12. Experimental Verification of a Jarzynski-Related Information-Theoretic Equality by a Single Trapped Ion.

    Science.gov (United States)

    Xiong, T P; Yan, L L; Zhou, F; Rehan, K; Liang, D F; Chen, L; Yang, W L; Ma, Z H; Feng, M; Vedral, V

    2018-01-05

    Most nonequilibrium processes in thermodynamics are quantified only by inequalities; however, the Jarzynski relation presents a remarkably simple and general equality relating nonequilibrium quantities with the equilibrium free energy, and this equality holds in both the classical and quantum regimes. We report a single-spin test and confirmation of the Jarzynski relation in the quantum regime using a single ultracold ^{40}Ca^{+} ion trapped in a harmonic potential, based on a general information-theoretic equality for a temporal evolution of the system sandwiched between two projective measurements. By considering both initially pure and mixed states, respectively, we verify, in an exact and fundamental fashion, the nonequilibrium quantum thermodynamics relevant to the mutual information and Jarzynski equality.

  13. Temporal Evolution of Ion Spectral Structures During a Geomagnetic Storm: Observations and Modeling

    Science.gov (United States)

    Ferradas, C. P.; Zhang, J.-C.; Spence, H. E.; Kistler, L. M.; Larsen, B. A.; Reeves, G. D.; Skoug, R. M.; Funsten, H. O.

    2018-01-01

    Using the Van Allen Probes/Helium, Oxygen, Proton, and Electron mass spectrometer, we perform a case study of the temporal evolution of ion spectral structures observed in the energy range of 1 to 50 keV throughout the geomagnetic storm of 2 October 2013. The ion spectral features are observed near the inner edge of the plasma sheet and are signatures of fresh transport from the plasma sheet into the inner magnetosphere. We find that the characteristics of the ion structures are determined by the intensity of the convection electric field. Prior to the beginning of the storm, the plasma sheet inner edge exhibits narrow nose spectral structures that vary little in energy across L values. Ion access to the inner magnetosphere during these times is limited to the nose energy bands. As convection is enhanced and large amounts of plasma are injected from the plasma sheet during the main phase of the storm, ion access occurs at a wide energy range, as no nose structures are observed. As the magnetosphere recovers from the storm, single noses and then multiple noses are observed once again. We use a model of ion drift and losses due to charge exchange to simulate the ion spectra and gain insight into the main observed features.

  14. Electron paramagnetic resonance and optical absorption of uranium ions diluted in CdF2 single crystals

    International Nuclear Information System (INIS)

    Pereira, J.J.C.R.

    1976-08-01

    The electron paramagnetic resonance (EPR) has been studied in conection with the optical absortion spectra of Uranium ions diluted in CdF 2 single crystals. Analyses of the EPR and optical absorption spectra obtained experimentally, and a comparison with known results in the isomorfic CaF 2 , SrF 2 and BaF 2 , allowed the identification of two paramagnetic centers associated with Uranium ions. These are the U(2+) ion in cubic symmetry having the triplet γ 5 as ground state, and the U(3+) ion in cubic symmetry having the dublet γ 6 as ground state. (Author) [pt

  15. Realistic modeling of chamber transport for heavy-ion fusion

    International Nuclear Information System (INIS)

    Sharp, W.M.; Grote, D.P.; Callahan, D.A.; Tabak, M.; Henestroza, E.; Yu, S.S.; Peterson, P.F.; Welch, D.R.; Rose, D.V.

    2003-01-01

    Transport of intense heavy-ion beams to an inertial-fusion target after final focus is simulated here using a realistic computer model. It is found that passing the beam through a rarefied plasma layer before it enters the fusion chamber can largely neutralize the beam space charge and lead to a usable focal spot for a range of ion species and input conditions

  16. Development of the IFJ single ion hit facility for cells irradiation

    International Nuclear Information System (INIS)

    Veselov, O.; Polak, W.; Ugenskiene, R.; Hajduk, R.; Lebed, K.; Lekki, J.; Horwacik, T.; Dutkiewicz, E.M.; Maranda, S.; Pieprzyca, T.; Sarnecki, C.; Stachura, Z.; Szklarz, Z.; Styczen, J.

    2005-12-01

    In recent years a single ion hit facility (SIHF) has been constructed at the IFJ ion microprobe. The setup is used for the precise irradiations of living cells by a controlled number of ions. The facility allows investigations in various aspects of biomedical research, such as adaptive response, bystander effect, inverse dose-rate effect, low-dose hypersensitivity, etc. Those investigations have two very important requirements: (i) cells must be examined in their natural state and environment, i.e. without previously being killed, and preferentially, neither fixed nor stained, and (ii) a possibility of automatic irradiation of large number of cells with a computer recognition of their positions must be provided. This work presents some of the crucial features of the off-line and on-line optical systems, including self-developed software responsible for the automatic cell recognition. We also show several tests carried out to determine the efficiency of the whole setup and some segments. In conclusion, the results of our first irradiation measurements performed with living cells are demonstrated. (author)

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  18. Nanomechanical investigation of ion implanted single crystals - Challenges, possibilities and pitfall traps related to nanoindentation

    Science.gov (United States)

    Kurpaska, Lukasz

    2017-10-01

    Nanoindentation technique have developed considerably over last thirty years. Nowadays, commercially available systems offer very precise measurement in nano- and microscale, environmental noise cancelling (or at least noise suppressing), in situ high temperature indentation in controlled atmosphere and vacuum conditions and different additional options, among them dedicated indentation is one of the most popular. Due to its high precision, and ability to measure mechanical properties from very small depths (tens of nm), this technique become quite popular in the nuclear society. It is known that ion implantation (to some extent) can simulate the influence of neutron flux. However, depth of the material damage is very limited resulting in creation of thin layer of modified material over unmodified bulk. Therefore, only very precise technique, offering possibility to control depth of the measurement can be used to study functional properties of the material. For this reason, nanoindentation technique seems to be a perfect tool to investigate mechanical properties of ion implanted specimens. However, conducting correct nanomechanical experiment and extracting valuable mechanical parameters is not an easy task. In this paper a discussion about the nanoindentation tests performed on ion irradiated YSZ single crystal is presented. The goal of this paper is to discuss possible traps when studying mechanical properties of such materials and thin coatings.

  19. Complete momentum balance for single ionization of helium by fast ion impact: I. Experiment

    International Nuclear Information System (INIS)

    Moshammer, R.; Kollmus, H.; Unverzagt, M.; Schmidt-Boecking, H.; Wood, C.J.; Olson, R.E.

    1997-02-01

    The collision dynamics of He single ionization by 3.6 MeV/u Se 28+ impact was explored using the GSI-reaction microscope, a high resolution integrated multi electron - recoil-ion momentum spectrometer. The complete three particle final state momentum distribution (9 cartesian components p i ) was imaged with a resolution of Δp i ∼ ±0.1 a.u. by measuring the three momentum components of the emitted electron and the recoiling target-ion in coincidence. The projectile energy loss has been determined on a level of ΔE p /E p ∼ 10 -7 and projectile scattering angles as small as Δθ ∼ 10 -7 rad became accessible. The experimental data which are compared with results of classical trajectory Monte-Carlo (CTMC) calculations reveal an unprecedented insight into the details of the electron emission and the collision dynamics for ionization of helium by fast heavy-ion impact. (orig.)

  20. Complete momentum balance for single ionization of helium by fast ion impact: I. Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Moshammer, R.; Kollmus, H.; Unverzagt, M.; Schmidt-Boecking, H. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik; Ullrich, J.; Schmitt, W. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Wood, C.J.; Olson, R.E. [Missouri Univ., Rolla, MO (United States). Dept. of Physics

    1997-02-01

    The collision dynamics of He single ionization by 3.6 MeV/u Se{sup 28+} impact was explored using the GSI-reaction microscope, a high resolution integrated multi electron - recoil-ion momentum spectrometer. The complete three particle final state momentum distribution (9 cartesian components p{sub i}) was imaged with a resolution of {Delta}p{sub i} {approx} {+-}0.1 a.u. by measuring the three momentum components of the emitted electron and the recoiling target-ion in coincidence. The projectile energy loss has been determined on a level of {Delta}E{sub p}/E{sub p} {approx} 10{sup -7} and projectile scattering angles as small as {Delta}{theta} {approx} 10{sup -7}rad became accessible. The experimental data which are compared with results of classical trajectory Monte-Carlo (CTMC) calculations reveal an unprecedented insight into the details of the electron emission and the collision dynamics for ionization of helium by fast heavy-ion impact. (orig.)

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

    KAUST Repository

    Tu, Zhengyuan

    2017-09-21

    Substrates able to rectify transport of ions based on charge and/or size are ubiquitous in biological systems. Electrolytes and interphases that selectively transport electrochemically active ions are likewise of broad interest in all electrical energy storage technologies. In lithium-ion batteries, electrolytes with single- or near-single-ion conductivity reduce losses caused by ion polarization. In emergent lithium or sodium metal batteries, they maintain high conductivity at the anode and stabilize metal deposition by fundamental mechanisms. We report that 20- to 300-nm-thick, single-ion-conducting membranes deposited at the anode enable electrolytes with the highest combination of cation transference number, ionic conductivity, and electrochemical stability reported. By means of direct visualization we find that single-ion membranes also reduce dendritic deposition of Li in liquids. Galvanostatic measurements further show that the electrolytes facilitate long (3 mAh) recharge of full Li/LiNi0.8Co0.15Al0.05O2 (NCA) cells with high cathode loadings (3 mAh cm−2/19.9 mg cm−2) and at high current densities (3 mA cm−2).

  2. Investigation of the lithium ion mobility in cyclic model compounds and their ion conduction properties

    Energy Technology Data Exchange (ETDEWEB)

    Thielen, Joerg

    2011-07-27

    In view of both, energy density and energy drain, rechargeable lithium ion batteries outperform other present accumulator systems. However, despite great efforts over the last decades, the ideal electrolyte in terms of key characteristics such as capacity, cycle life, and most important reliable safety, has not yet been identified. Steps ahead in lithium ion battery technology require a fundamental understanding of lithium ion transport, salt association, and ion solvation within the electrolyte. Indeed, well defined model compounds allow for systematic studies of molecular ion transport. Thus, in the present work, based on the concept of immobilizing ion solvents, three main series with a cyclotriphosphazene (CTP), hexaphenylbenzene (HBP), and tetramethylcyclotetrasiloxane (TMS) scaffold were prepared. Lithium ion solvents, among others ethylene carbonate (EC), which has proven to fulfill together with propylene carbonate safety and market concerns in commercial lithium ion batteries, were attached to the different cores via alkyl spacers of variable length. All model compounds were fully characterized, pure and thermally stable up to at least 235 C, covering the requested broad range of glass transition temperatures from -78.1 C up to +6.2 C. While the CTP models tend to rearrange at elevated temperatures over time, which questions the general stability of alkoxide related (poly)phosphazenes, both, the HPB and CTP based models show no evidence of core stacking. In particular the CTP derivatives represent good solvents for various lithium salts, exhibiting no significant differences in the ionic conductivity {sigma}{sub dc} and thus indicating comparable salt dissociation and rather independent motion of cations and ions. In general, temperature-dependent bulk ionic conductivities investigated via impedance spectroscopy follow a William-Landel-Ferry (WLF) type behavior. Modifications of the alkyl spacer length were shown to influence ionic conductivities only in

  3. Single and binary adsorption of Cd (Ⅱ) and Zn (Ⅱ) ions from aqueous solutions onto bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Sukpreabprom, Hatairat; Arqueropanyo, Orn-anong; Naksata, Wimol; Janhom, Sorapong [Chiang Mai University, Chiang Mai (Thailand); Sooksamiti, Ponlayuth [The Office of Primary Industries and Mines Region 3, Chiang Mai (Thailand)

    2015-05-15

    Bottom ash, a waste obtained from coal-burning power plant, was used as a low cost adsorbent for the removal of Cd (Ⅱ) and Zn (Ⅱ) ions from single and binary systems in batch experiments. The results of adsorption capacity showed that bottom ash could be considered as a potential adsorbent. The uptake of Zn (Ⅱ) ion was greater than that of Cd (Ⅱ) ion. For single adsorption, based on the correlation coefficient (R{sup 2}) values, both Langmuir and Freundlich isotherms suitably described the adsorption equilibrium data in the initial metal ion concentration range of 10-50 mg/L. The multicomponent isotherms, including the extended Langmuir and IAST-Freundlich isotherms, were used to predict the binary adsorption of Cd (Ⅱ) and Zn (Ⅱ) ions. Furthermore, the appropriate multicomponent isotherm was investigated by minimizing the average relative error (ARE) function. It should be confirmed that the extended Langmuir isotherm fitted the binary adsorption equilibrium data satisfactorily.

  4. Mathematical Model of Ion Transport in Electrodialysis Process

    Directory of Open Access Journals (Sweden)

    F.S. Rohman

    2010-10-01

    Full Text Available Mathematical models of ion transport in electrodialysis process is reviewed and their basics concept is discussed. Three scales of ion transport reviewed are: 1 ion transport in the membrane, where two approaches are used, the irreversible thermodynamics and modeling of the membrane material; 2 ion transport in a three-layer system composed of a membrane with two adjoining diffusion layers; and 3 coupling with hydraulic flow system in an electrodialysis 2D and 3D cell, where the differential equation of convectivediffusion is used. Most of the work carried out in the past implemented NP equations since relatively easily coupled with other equations describing hydrodynamic conditions and ion transport in the surrounding solutions, chemical reactions in the solutions and the membrane, boundary and other conditions. However, it is limited to point ionic transport in homogenous and uniformly - grainy phases of structure. © 2008 BCREC UNDIP. All rights reserved.[Received: 21 January 2008, Accepted: 10 March 2008][How to Cite: F.S. Rohman, N. Aziz (2008. Mathematical Model of Ion Transport in Electrodialysis Process. Bulletin of Chemical Reaction Engineering and Catalysis, 3(1-3: 3-8. doi:10.9767/bcrec.3.1-3.7122.3-8][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.3.1-3.7122.3-8 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/7122 ] 

  5. Computational stochastic model of ions implantation

    Energy Technology Data Exchange (ETDEWEB)

    Zmievskaya, Galina I., E-mail: zmi@gmail.ru; Bondareva, Anna L., E-mail: bal310775@yandex.ru [M.V. Keldysh Institute of Applied Mathematics RAS, 4,Miusskaya sq., 125047 Moscow (Russian Federation); Levchenko, Tatiana V., E-mail: tatlevchenko@mail.ru [VNII Geosystem Russian Federal Center, Varshavskoye roadway, 8, Moscow (Russian Federation); Maino, Giuseppe, E-mail: giuseppe.maino@enea.it [Scuola di Lettere e BeniCulturali, University di Bologna, sede di Ravenna, via Mariani 5, 48100 Ravenna (Italy)

    2015-03-10

    Implantation flux ions into crystal leads to phase transition /PT/ 1-st kind. Damaging lattice is associated with processes clustering vacancies and gaseous bubbles as well their brownian motion. System of stochastic differential equations /SDEs/ Ito for evolution stochastic dynamical variables corresponds to the superposition Wiener processes. The kinetic equations in partial derivatives /KE/, Kolmogorov-Feller and Einstein-Smolukhovskii, were formulated for nucleation into lattice of weakly soluble gases. According theory, coefficients of stochastic and kinetic equations uniquely related. Radiation stimulated phase transition are characterized by kinetic distribution functions /DFs/ of implanted clusters versus their sizes and depth of gas penetration into lattice. Macroscopic parameters of kinetics such as the porosity and stress calculated in thin layers metal/dielectric due to Xe{sup ++} irradiation are attracted as example. Predictions of porosity, important for validation accumulation stresses in surfaces, can be applied at restoring of objects the cultural heritage.

  6. Ion implantation effects in single crystal Si investigated by Raman spectroscopy

    International Nuclear Information System (INIS)

    Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

    2009-01-01

    A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

  7. Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate

    International Nuclear Information System (INIS)

    Sun Xiaoguang; Hou Jun; Kerr, John B.

    2005-01-01

    Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li + salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE 8 -co-E 3 SO 3 Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE 8 -g-E n SO 3 Li, n = 2, 3). The highest conductivity at 25 deg. C of 2.0 x 10 -7 S cm -1 was obtained for the PAE 8 -co-E 3 SO 3 Li with a salt concentration of EO/Li = 40. The conductivity of PAE 8 -g-E 3 SO 3 Li is lower than that of PAE 8 -co-E 3 SO 3 Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li + . The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE 8 -g-E 2 SO 3 Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 μA cm -2 at 85 deg. C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer

  8. Bistable dynamics underlying excitability of ion homeostasis in neuron models.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    2014-05-01

    Full Text Available When neurons fire action potentials, dissipation of free energy is usually not directly considered, because the change in free energy is often negligible compared to the immense reservoir stored in neural transmembrane ion gradients and the long-term energy requirements are met through chemical energy, i.e., metabolism. However, these gradients can temporarily nearly vanish in neurological diseases, such as migraine and stroke, and in traumatic brain injury from concussions to severe injuries. We study biophysical neuron models based on the Hodgkin-Huxley (HH formalism extended to include time-dependent ion concentrations inside and outside the cell and metabolic energy-driven pumps. We reveal the basic mechanism of a state of free energy-starvation (FES with bifurcation analyses showing that ion dynamics is for a large range of pump rates bistable without contact to an ion bath. This is interpreted as a threshold reduction of a new fundamental mechanism of ionic excitability that causes a long-lasting but transient FES as observed in pathological states. We can in particular conclude that a coupling of extracellular ion concentrations to a large glial-vascular bath can take a role as an inhibitory mechanism crucial in ion homeostasis, while the Na⁺/K⁺ pumps alone are insufficient to recover from FES. Our results provide the missing link between the HH formalism and activator-inhibitor models that have been successfully used for modeling migraine phenotypes, and therefore will allow us to validate the hypothesis that migraine symptoms are explained by disturbed function in ion channel subunits, Na⁺/K⁺ pumps, and other proteins that regulate ion homeostasis.

  9. Hydrodynamic modelling for relativistic heavy-ion collisions at RHIC ...

    Indian Academy of Sciences (India)

    model, to describe the microscopic evolution and decoupling of the hadronic ... progress on hydrodynamic modelling, investigation on the flow data and the ... and to describe and predict the soft particle physics in relativistic heavy-ion collisions [4]. It is based on the conservation laws of energy, momentum and net charge ...

  10. Modeling of Jupiter's electron an ion radiation belts

    International Nuclear Information System (INIS)

    Sicard, Angelica

    2004-01-01

    In the Fifties, James Van Allen showed the existence of regions of the terrestrial magnetosphere consisted of energetic particles, trapped by the magnetic field: the radiation belts. The radiation belts of the Earth were the subject of many modeling works and are studied since several years at the Departement Environnement Spatial (DESP) of ONERA. In 1998, the DESP decided to adapt the radiation belts model of the Earth, Salammbo, to radiation environment of Jupiter. A first thesis was thus carried out on the subject and a first radiation belts model of electrons of Jupiter was developed [Santos-Costa, 2001]. The aim of this second thesis is to develop a radiation belts model for protons and heavy ions. In order to validate the developed model, the comparisons between Salammbo results and observations are essential. However, the validation is difficult in the case of protons and heavy ions because in-situ measurements of the probes are very few and most of the time contaminated by very energetic electrons. To solve this problem, a very good model of electrons radiation belts is essential to confirm or cancel the contamination of protons and heavy ions measurements. Thus, in parallel to the development of the protons and heavy ions radiation belts model, the electrons models, already existing, has been improved. Then Salammbo results have been compared to the different observations available (in-situ measurements, radio-astronomical observations). The different comparisons show a very good agreement between Salammbo results and observations. (author) [fr

  11. Multi-shell model of ion-induced nucleic acid condensation

    Energy Technology Data Exchange (ETDEWEB)

    Tolokh, Igor S. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061 (United States); Drozdetski, Aleksander V. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Pollack, Lois [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853-3501 (United States); Baker, Nathan A. [Advanced Computing, Mathematics, and Data Division, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912 (United States); Onufriev, Alexey V. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061 (United States); Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2016-04-21

    We present a semi-quantitative model of condensation of short nucleic acid (NA) duplexes induced by trivalent cobalt(III) hexammine (CoHex) ions. The model is based on partitioning of bound counterion distribution around single NA duplex into “external” and “internal” ion binding shells distinguished by the proximity to duplex helical axis. In the aggregated phase the shells overlap, which leads to significantly increased attraction of CoHex ions in these overlaps with the neighboring duplexes. The duplex aggregation free energy is decomposed into attractive and repulsive components in such a way that they can be represented by simple analytical expressions with parameters derived from molecular dynamic simulations and numerical solutions of Poisson equation. The attractive term depends on the fractions of bound ions in the overlapping shells and affinity of CoHex to the “external” shell of nearly neutralized duplex. The repulsive components of the free energy are duplex configurational entropy loss upon the aggregation and the electrostatic repulsion of the duplexes that remains after neutralization by bound CoHex ions. The estimates of the aggregation free energy are consistent with the experimental range of NA duplex condensation propensities, including the unusually poor condensation of RNA structures and subtle sequence effects upon DNA condensation. The model predicts that, in contrast to DNA, RNA duplexes may condense into tighter packed aggregates with a higher degree of duplex neutralization. An appreciable CoHex mediated RNA-RNA attraction requires closer inter-duplex separation to engage CoHex ions (bound mostly in the “internal” shell of RNA) into short-range attractive interactions. The model also predicts that longer NA fragments will condense more readily than shorter ones. The ability of this model to explain experimentally observed trends in NA condensation lends support to proposed NA condensation picture based on the multivalent “ion

  12. Modeling space charge in beams for heavy-ion fusion

    International Nuclear Information System (INIS)

    Sharp, W.M.

    1995-01-01

    A new analytic model is presented which accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy-ion beam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well to exact solutions of Poisson's equation. Field values are shown for several simple beam profiles and are compared with values obtained from simpler models

  13. The complex formation-partition and partition-association models of solvent extraction of ions

    International Nuclear Information System (INIS)

    Siekierski, S.

    1976-01-01

    Two models of the extraction process have been proposed. In the first model it is assumed that the partitioning neutral species is at first formed in the aqueous phase and then transferred into the organic phase. The second model is based on the assumption that equivalent amounts of cations are at first transferred from the aqueous into the organic phase and then associated to form a neutral molecule. The role of the solubility parameter in extraction and the relation between the solubility of liquid organic substances in water and the partition of complexes have been discussed. The extraction of simple complexes and complexes with organic ligands has been discussed using the first model. Partition coefficients have been calculated theoretically and compared with experimental values in some very simple cases. The extraction of ion pairs has been discussed using the partition-association model and the concept of single-ion partition coefficients. (author)

  14. Modeling of Jovian Auroral Polar Ion and Proton Precipitation

    Science.gov (United States)

    Houston, S. J.; Ozak, N. O.; Cravens, T.; Schultz, D. R.; Mauk, B.; Haggerty, D. K.; Young, J. T.

    2017-12-01

    Auroral particle precipitation dominates the chemical and physical environment of the upper atmospheres and ionospheres of the outer planets. Precipitation of energetic electrons from the middle magnetosphere is responsible for the main auroral oval at Jupiter, but energetic electron, proton, and ion precipitation take place in the polar caps. At least some of the ion precipitation is associated with soft X-ray emission with about 1 GW of power. Theoretical modeling has demonstrated that the incident sulfur and oxygen ion energies must exceed about 0.5 MeV/nucleon (u) in order to produce the measured X-ray emission. In this work we present a model of the transport of magnetospheric oxygen ions as they precipitate into Jupiter's polar atmosphere. We have revised and updated the hybrid Monte Carlo model originally developed by Ozak et al., 2010 to model the Jovian X-ray aurora. We now simulate a wider range of incident oxygen ion energies (10 keV/u - 5 MeV/u) and update the collision cross-sections to model the ionization of the atmospheric neutrals. The polar cap location of the emission and magnetosphere-ionosphere coupling both indicate the associated field-aligned currents must originate near the magnetopause or perhaps the distant tail. Secondary electrons produced in the upper atmosphere by ion precipitation could be accelerated upward to relativistic energies due to the same field-aligned potentials responsible for the downward ion acceleration. To further explore this, we simulate the effect of the secondary electrons generated from the heavy ion precipitation. We use a two-stream transport model that computes the secondary electron fluxes, their escape from the atmosphere, and characterization of the H2 Lyman-Werner band emission, including a predicted observable spectrum with the associated color ratio. Our model predicts that escaping electrons have an energy range from 1 eV to 6 keV, H2 band emission rates produced are on the order of 75 kR for an input

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  16. Analytic model of Applied-B ion diode impedance behavior

    International Nuclear Information System (INIS)

    Miller, P.A.; Mendel, C.W. Jr.

    1987-01-01

    An empirical analysis of impedance data from Applied-B ion diodes used in seven inertial confinement fusion research experiments was published recently. The diodes all operated with impedance values well below the Child's-law value. The analysis uncovered an unusual unifying relationship among data from the different experiments. The analysis suggested that closure of the anode-cathode gap by electrode plasma was not a dominant factor in the experiments, but was not able to elaborate the underlying physics. Here we present a new analytic model of Applied-B ion diodes coupled to accelerators. A critical feature of the diode model is based on magnetic insulation theory. The model successfully describes impedance behavior of these diodes and supports stimulating new viewpoints of the physics of Applied-B ion diode operation

  17. Statistical 3D damage accumulation model for ion implant simulators

    CERN Document Server

    Hernandez-Mangas, J M; Enriquez, L E; Bailon, L; Barbolla, J; Jaraiz, M

    2003-01-01

    A statistical 3D damage accumulation model, based on the modified Kinchin-Pease formula, for ion implant simulation has been included in our physically based ion implantation code. It has only one fitting parameter for electronic stopping and uses 3D electron density distributions for different types of targets including compound semiconductors. Also, a statistical noise reduction mechanism based on the dose division is used. The model has been adapted to be run under parallel execution in order to speed up the calculation in 3D structures. Sequential ion implantation has been modelled including previous damage profiles. It can also simulate the implantation of molecular and cluster projectiles. Comparisons of simulated doping profiles with experimental SIMS profiles are presented. Also comparisons between simulated amorphization and experimental RBS profiles are shown. An analysis of sequential versus parallel processing is provided.

  18. Statistical 3D damage accumulation model for ion implant simulators

    International Nuclear Information System (INIS)

    Hernandez-Mangas, J.M.; Lazaro, J.; Enriquez, L.; Bailon, L.; Barbolla, J.; Jaraiz, M.

    2003-01-01

    A statistical 3D damage accumulation model, based on the modified Kinchin-Pease formula, for ion implant simulation has been included in our physically based ion implantation code. It has only one fitting parameter for electronic stopping and uses 3D electron density distributions for different types of targets including compound semiconductors. Also, a statistical noise reduction mechanism based on the dose division is used. The model has been adapted to be run under parallel execution in order to speed up the calculation in 3D structures. Sequential ion implantation has been modelled including previous damage profiles. It can also simulate the implantation of molecular and cluster projectiles. Comparisons of simulated doping profiles with experimental SIMS profiles are presented. Also comparisons between simulated amorphization and experimental RBS profiles are shown. An analysis of sequential versus parallel processing is provided

  19. Wave Model Development in Multi-Ion Plasmas

    Directory of Open Access Journals (Sweden)

    Sung-Hee Song

    1999-06-01

    Full Text Available Near-earth space is composed of plasmas which embed a number of plasma waves. Space plasmas consist of electrons and multi-ion that determine local wave propagation characteristics. In multi-ion plasmas, it is di cult to find out analytic solution from the dispersion relation in general. In this work, we have developed a model with an arbitrary magnetic field and density as well as multi-ion plasmas. This model allows us to investigate how plasma waves behave when they propagate along realistic magnetic field lines, which are assumed by IGRF(International Geomagnetic Reference Field. The results are found to be useful for the analysis of the in situ observational data in space. For instance, if waves are assumed to propagate into the polar region, from the equatorial region, our model quantitatively shows how polarization is altered along earth travel path.

  20. Analog quantum simulation of generalized Dicke models in trapped ions

    Science.gov (United States)

    Aedo, Ibai; Lamata, Lucas

    2018-04-01

    We propose the analog quantum simulation of generalized Dicke models in trapped ions. By combining bicromatic laser interactions on multiple ions we can generate all regimes of light-matter coupling in these models, where here the light mode is mimicked by a motional mode. We present numerical simulations of the three-qubit Dicke model both in the weak field (WF) regime, where the Jaynes-Cummings behavior arises, and the ultrastrong coupling (USC) regime, where a rotating-wave approximation cannot be considered. We also simulate the two-qubit biased Dicke model in the WF and USC regimes and the two-qubit anisotropic Dicke model in the USC regime and the deep-strong coupling regime. The agreement between the mathematical models and the ion system convinces us that these quantum simulations can be implemented in the laboratory with current or near-future technology. This formalism establishes an avenue for the quantum simulation of many-spin Dicke models in trapped ions.

  1. Realistic modelling of jets in heavy-ion collisions

    International Nuclear Information System (INIS)

    Young, Clint; Schenke, Björn; Jeon, Sangyong; Gale, Charles

    2013-01-01

    The reconstruction of jets in heavy-ion collisions provides insight into the dynamics of hard partons in media. Unlike the spectrum of single hadrons, the spectrum of jets is highly sensitive to q -hat ⊥ , as well as being sensitive to partonic energy loss and radiative processes. We use martini, an event generator, to study how finite-temperature processes at leading order affect dijets

  2. Effective tuning of the ratio of red to green emission of Ho"3"+ ions in single LiLuF_4 microparticle via codoping Ce"3"+ ions

    International Nuclear Information System (INIS)

    Gao, Wei; Dong, Jun; Liu, Jihong; Yan, Xuewen

    2016-01-01

    Yb"3"+/Ho"3"+ codoped LiLuF_4 microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF_4 microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF_4: Yb"3"+/Ho"3"+ microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce"3"+ ion concentrations of 12%, the ratio of red to green emission of the Ho"3"+ ions of single LiLuF_4 microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho"3"+ and Ce"3"+ ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho"3"+ in single LiLuF_4 microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

  3. Features of produced flows of multiply charged ions at interaction of laser radiation with single-component solids

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Bedilov, R.M.; Beysembaeva, H.B.; Sabitov, M.S.; Kamalova, J.O.

    2006-01-01

    Full text: The results of study features of formation multiply charged ions spectra of single-component solids depending on a target element composition in an interval of laser radiation power density q = 10 7 / 10 12 W/cm 2 with using of the laser multiply charged mass spectrometer [1] are given in this work. As single-component targets are used Be, B, C, Al, Ti, Fe, Co, Ni, Cu, Ag, Ta, W, Pt, Au as tablets in diameter of 10 mm and thickness of 3-5 mm. Analysis of the obtained mass-charge and energy spectra of multiply charged ions depending on a target element composition has allowed us to find features of formation spectra and escape multiply charged ions of a single-component targets. These features consist in characteristic changes: a threshold produced of ions; formation of mass-charge and energy spectra of multiply charged ions; nonlinear dependence of maximal charge number (Z max ) of ions from power density (q) of the laser; etc. Experimentally it was found that, with target atomic weight increase, threshold power of ions occurrence, nonlinearity ionization target structure, and intensity of ions, and energy spectra of ions increase. Let's note that, in case of targets Be, B, C, Al by laser radiation it is completely ionized and multiply charged ions and nuclei Be 4+ , B 5+ , C 6+ , Al 13+ are formed. The major level of ionization is attained in case of targets from Ti (Ti 17+ ) and Co (Co 18+ ). It is peculiar that structure formation and escape of multiply charged ion flows with Z max and nuclei depending on target element composition corresponds to various maximal values q of the laser. Increase of the maximal charge number of ions (atoms) observed with increase q of the laser for all investigated targets has nonlinear dependence in various levels that is especially shown beginning from q≥ 10 11 W/cm 2 . It is found that depending on target element composition multiply charged ions have a wide energy range with a maximum of allocation. With increase

  4. Rank-based model selection for multiple ions quantum tomography

    International Nuclear Information System (INIS)

    Guţă, Mădălin; Kypraios, Theodore; Dryden, Ian

    2012-01-01

    The statistical analysis of measurement data has become a key component of many quantum engineering experiments. As standard full state tomography becomes unfeasible for large dimensional quantum systems, one needs to exploit prior information and the ‘sparsity’ properties of the experimental state in order to reduce the dimensionality of the estimation problem. In this paper we propose model selection as a general principle for finding the simplest, or most parsimonious explanation of the data, by fitting different models and choosing the estimator with the best trade-off between likelihood fit and model complexity. We apply two well established model selection methods—the Akaike information criterion (AIC) and the Bayesian information criterion (BIC)—two models consisting of states of fixed rank and datasets such as are currently produced in multiple ions experiments. We test the performance of AIC and BIC on randomly chosen low rank states of four ions, and study the dependence of the selected rank with the number of measurement repetitions for one ion states. We then apply the methods to real data from a four ions experiment aimed at creating a Smolin state of rank 4. By applying the two methods together with the Pearson χ 2 test we conclude that the data can be suitably described with a model whose rank is between 7 and 9. Additionally we find that the mean square error of the maximum likelihood estimator for pure states is close to that of the optimal over all possible measurements. (paper)

  5. Hopping models for ion conduction in noncrystals

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Schrøder, Thomas

    2007-01-01

    semiconductors). These universalities are subject of much current interest, for instance interpreted in the context of simple hopping models. In the present paper we first discuss the temperature dependence of the dc conductivity in hopping models and the importance of the percolation phenomenon. Next......, the experimental (quasi)universality of the ac conductivity is discussed. It is shown that hopping models are able to reproduce the experimental finding that the response obeys time-temperature superposition, while at the same time a broad range of activation energies is involved in the conduction process. Again...

  6. Modelling of ion implantation in SiC crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chakarov, Ivan [SILVACO International, 4701 Patrick Henry Drive, Building 2, Santa Clara, CA 95054 (United States)]. E-mail: ivan.chakarov@silvaco.com; Temkin, Misha [SILVACO International, 4701 Patrick Henry Drive, Building 2, Santa Clara, CA 95054 (United States)

    2006-01-15

    An advanced electronic stopping model for ion implantation in SiC has been implemented within the binary collision approximation. The model has been thoroughly tested and validated for Al implantation into 4H-, 6H-SiC under different initial implant conditions. A very good agreement between calculated and experimental profiles has been achieved. The model has been integrated in an industrial technology CAD process simulator.

  7. Modelling of ion implantation in SiC crystals

    International Nuclear Information System (INIS)

    Chakarov, Ivan; Temkin, Misha

    2006-01-01

    An advanced electronic stopping model for ion implantation in SiC has been implemented within the binary collision approximation. The model has been thoroughly tested and validated for Al implantation into 4H-, 6H-SiC under different initial implant conditions. A very good agreement between calculated and experimental profiles has been achieved. The model has been integrated in an industrial technology CAD process simulator

  8. The multistring model VENUS for ultrarelativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Werner, K.

    1988-02-01

    The event generator VENUS is based on a multistring model for heavy ion collisions at ultrarelativistic energies. The model is a straightforward extension of a successful model for soft proton-proton scattering, the latter one being consistent with e/sup /plus//e/sup /minus// annihilation and deep inelastic lepton scattering. Comparisons of VENUS results with pA and recent AA data alow some statements about intranuclear cascading. 18 refs., 7 figs

  9. Single impacts of keV fullerene ions on free standing graphene: Emission of ions and electrons from confined volume

    Energy Technology Data Exchange (ETDEWEB)

    Verkhoturov, Stanislav V.; Geng, Sheng; Schweikert, Emile A., E-mail: schweikert@chem.tamu.edu [Department of Chemistry, Texas A& M University, College Station, Texas 77843-3144 (United States); Czerwinski, Bartlomiej [Institute of Condensed Matter and Nanosciences–Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium); Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå (Sweden); Young, Amanda E. [Materials Characterization Facility, Texas A& M University, College Station, Texas 77843-3122 (United States); Delcorte, Arnaud [Institute of Condensed Matter and Nanosciences–Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium)

    2015-10-28

    We present the first data from individual C{sub 60} impacting one to four layer graphene at 25 and 50 keV. Negative secondary ions and electrons emitted in transmission were recorded separately from each impact. The yields for C{sub n}{sup −} clusters are above 10% for n ≤ 4, they oscillate with electron affinities and decrease exponentially with n. The result can be explained with the aid of MD simulation as a post-collision process where sufficient vibrational energy is accumulated around the rim of the impact hole for sputtering of carbon clusters. The ionization probability can be estimated by comparing experimental yields of C{sub n}{sup −} with those of C{sub n}{sup 0} from MD simulation, where it increases exponentially with n. The ionization probability can be approximated with ejecta from a thermally excited (3700 K) rim damped by cluster fragmentation and electron detachment. The experimental electron probability distributions are Poisson-like. On average, three electrons of thermal energies are emitted per impact. The thermal excitation model invoked for C{sub n}{sup −} emission can also explain the emission of electrons. The interaction of C{sub 60} with graphene is fundamentally different from impacts on 3D targets. A key characteristic is the high degree of ionization of the ejecta.

  10. [Application of classical isothermal adsorption models in heavy metal ions/ diatomite system and related problems].

    Science.gov (United States)

    Zhu, Jian; Wu, Qing-Ding; Wang, Ping; Li, Ke-Lin; Lei, Ming-Jing; Zhang, Wei-Li

    2013-11-01

    In order to fully understand adsorption nature of Cu2+, Zn2+, Pb2+, Cd2+, Mn2+, Fe3+ onto natural diatomite, and to find problems of classical isothermal adsorption models' application in liquid/solid system, a series of isothermal adsorption tests were conducted. As results indicate, the most suitable isotherm models for describing adsorption of Pb2+, Cd2+, Cu2+, Zn2+, Mn2+, Fe3+ onto natural diatomite are Tenkin, Tenkin, Langmuir, Tenkin, Freundlich and Freundlich, respectively, the adsorption of each ion onto natural diatomite is mainly a physical process, and the adsorption reaction is favorable. It also can be found that, when using classical isothermal adsorption models to fit the experimental data in liquid/solid system, the equilibrium adsorption amount q(e) is not a single function of ion equilibrium concentration c(e), while is a function of two variables, namely c(e) and the adsorbent concentration W0, q(e) only depends on c(e)/W(0). Results also show that the classical isothermal adsorption models have a significant adsorbent effect, and their parameter values are unstable, the simulation values of parameter differ greatly from the measured values, which is unhelpful for practical use. The tests prove that four-adsorption-components model can be used for describing adsorption behavior of single ion in nature diatomite-liquid system, its parameters k and q(m) have constant values, which is favorable for practical quantitative calculation in a given system.

  11. Full characterization of laser-accelerated ion beams using Faraday cup, silicon carbide, and single-crystal diamond detectors

    Science.gov (United States)

    Margarone, D.; Krása, J.; Giuffrida, L.; Picciotto, A.; Torrisi, L.; Nowak, T.; Musumeci, P.; Velyhan, A.; Prokůpek, J.; Láska, L.; Mocek, T.; Ullschmied, J.; Rus, B.

    2011-05-01

    Multi-MeV beams of light ions have been produced using the 300 picosecond, kJ-class iodine laser, operating at the Prague Asterix Laser System facility in Prague. Real-time ion diagnostics have been performed by the use of various time-of-flight (TOF) detectors: ion collectors (ICs) with and without absorber thin films, new prototypes of single-crystal diamond and silicon carbide detectors, and an electrostatic ion mass spectrometer (IEA). In order to suppress the long photopeak induced by soft X-rays and to avoid the overlap with the signal from ultrafast particles, the ICs have been shielded with Al foil filters. The application of large-bandgap semiconductor detectors (>3 eV) ensured cutting of the plasma-emitted visible and soft-UV radiation and enhancing the sensitivity to the very fast proton/ion beams. Employing the IEA spectrometer, various ion species and charge states in the expanding laser-plasma have been determined. Processing of the experimental data based on the TOF technique, including estimation of the plasma fast proton maximum and peak energy, ion beam currents and total charge, total number of fast protons, as well as deconvolution processes, ion stopping power, and ion/photon transmission calculations for the different metallic filters used, are reported.

  12. Angle-resolved imaging of single-crystal materials with MeV helium ions

    Energy Technology Data Exchange (ETDEWEB)

    Strathman, M D; Baumann, S [Charles Evans and Associates, Redwood City, CA (United States)

    1992-02-01

    The simplest form of angle-resolved mapping for single-crystal materials is the creation of a channeling angular scan. Several laboratories have expanded this simple procedure to include mapping as a function of two independent tilts. These angle-resolved images are particularly suited to the assessment of crystal parameters including disorder, lattice location of impurities, and lattice stress. This paper will describe the use of the Charles Evans and Associates RBS-400 scattering chamber for acquisition, display, and analysis of angle-resolved images obtained from backscattered helium ions. Typical data acquisition times are 20 min for a {+-}2deg X-Y tilt scan with 2500 pixels (8/100deg resolution), and 10 nC per pixel. In addition, we will present a method for automatically aligning crystals for channeling measurements based on this imaging technology. (orig.).

  13. Focused ion beam milling of nanocavities in single colloidal particles and self-assembled opals

    International Nuclear Information System (INIS)

    Woldering, Leon A; Otter, A M; Husken, Bart H; Vos, Willem L

    2006-01-01

    We present a new method of realizing single nanocavities in individual colloidal particles on the surface of silicon dioxide artificial opals using a focused ion beam milling technique. We show that both the radius and the position of the nanocavity can be controlled with nanometre precision, to radii as small as 40 nm. The relation between the defect size and the milling time has been established. We confirmed that milling not only occurs on the surface of the spheres, but into and through them as well. We also show that an array of nanocavities can be fashioned. Structurally modified colloids have interesting potential applications in nanolithography, as well as in chemical sensing and solar cells, and as photonic crystal cavities

  14. Single Ion transient-IBIC analyses of semiconductor devices using a cryogenic temperature stage

    International Nuclear Information System (INIS)

    Laird, J.S.; Bardos, R.; Legge, G.J.F.; Jagadish, C.

    1998-01-01

    A new Transient - IBIC data acquisition and analysis system at MARC is described. A discussion on the need for single ion control and temperature control is also given. The recorded signal is used as the trigger for beam pulsing. The new cryostatic temperature control stage is introduced. Data is presented on line profiles across the edge of a Au-Si junction collected over the temperature range of 25-300K using a developed C-V and I-V variable temperature stage incorporating a liquid helium cryostat. It demonstrates the potential improvements in spatial resolution in materials of long lifetime by mapping on timing windows around the prompt charge component in the charge transient

  15. Electron capture to the continuum manifestation in fully differential cross sections for ion impact single ionization

    Science.gov (United States)

    Ciappina, M. F.; Fojón, O. A.; Rivarola, R. D.

    2018-04-01

    We present theoretical calculations of single ionization of He atoms by protons and multiply charged ions. The kinematical conditions are deliberately chosen in such a way that the ejected electron velocity matches the projectile impact velocity. The computed fully differential cross sections (FDCS) in the scattering plane using the continuum-distorted wave-eikonal initial state show a distinct peaked structure for a polar electron emission angle θ k = 0°. This element is absent when a first order theory is employed. Consequently, we can argue that this peak is a clear manifestation of a three-body effect, not observed before in FDCS. We discuss a possible interpretation of this new feature.

  16. A single lithium-ion battery protection circuit with high reliability and low power consumption

    International Nuclear Information System (INIS)

    Jiang Jinguang; Li Sen

    2014-01-01

    A single lithium-ion battery protection circuit with high reliability and low power consumption is proposed. The protection circuit has high reliability because the voltage and current of the battery are controlled in a safe range. The protection circuit can immediately activate a protective function when the voltage and current of the battery are beyond the safe range. In order to reduce the circuit's power consumption, a sleep state control circuit is developed. Additionally, the output frequency of the ring oscillation can be adjusted continuously and precisely by the charging capacitors and the constant-current source. The proposed protection circuit is fabricated in a 0.5 μm mixed-signal CMOS process. The measured reference voltage is 1.19 V, the overvoltage is 4.2 V and the undervoltage is 2.2 V. The total power is about 9 μW. (semiconductor integrated circuits)

  17. Angle-resolved imaging of single-crystal materials with MeV helium ions

    International Nuclear Information System (INIS)

    Strathman, M.D.; Baumann, S.

    1992-01-01

    The simplest form of angle-resolved mapping for single-crystal materials is the creation of a channeling angular scan. Several laboratories have expanded this simple procedure to include mapping as a function of two independent tilts. These angle-resolved images are particularly suited to the assessment of crystal parameters including disorder, lattice location of impurities, and lattice stress. This paper will describe the use of the Charles Evans and Associates RBS-400 scattering chamber for acquisition, display, and analysis of angle-resolved images obtained from backscattered helium ions. Typical data acquisition times are 20 min for a ±2deg X-Y tilt scan with 2500 pixels (8/100deg resolution), and 10 nC per pixel. In addition, we will present a method for automatically aligning crystals for channeling measurements based on this imaging technology. (orig.)

  18. Luminescence of Bi3+ ions in Y3Al5O12:Bi single crystalline films

    International Nuclear Information System (INIS)

    Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Vistovsky, V.; Nedilko, S.; Nikl, M.

    2007-01-01

    The absorption and cathodoluminescence spectra of single crystalline films (SCF) of Y 3 Al 5 O 12 :Bi garnet depending on Bi concentration were analyzed. For consideration of the nature of the UV and visible Bi-related emission bands the time-resolved luminescence of Bi 3+ (ns 2 ) ions in YAG:Bi SCF was studied at 10 K under excitation by synchrotron radiation. The difference in the excitation spectra and emission decay of the UV and visible bands has been explained via radiative relaxation from the 3 P 1,0 excited states to the 1 S 0 ground state of the isolated and pair/clustered Bi 3+ emission centers in the garnet lattice, respectively

  19. Study of clean and ion bombardment damaged silver single crystal surfaces by work function measurements

    International Nuclear Information System (INIS)

    Chelvayohan, N.

    1982-06-01

    Work function values of the (110), (100) and (111) faces of silver single crystal were measured by the photoelectric emission method and found to be 4.14 +- 0.04 eV, 4.22 +-0.04 eV and 4.46 +- 0.02 eV respectively. Oxygen adsorption on the faces were studied by surface potential measurement. Strong oxygen adsorption was observed on (110) and (100) faces, whereas the (111) face was found to be inert for oxygen adsorption. Oxygen adsorption on the (111) face damaged by argon ion bombardment was also investigated. The above results were compared with those of early reported work function and oxygen adsorption values. (U.K.)

  20. Energy levels of the single excited states in NaI and Na-like ions

    International Nuclear Information System (INIS)

    El-Sherbini, T.M.; Wahby, A.S.

    1987-08-01

    Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

  1. Study on relations between heavy ions single event upset cross sections and γ accumulated doses

    International Nuclear Information System (INIS)

    He Chaohui; Geng Bin; Wang Yanping; Peng Honglun; Yang Hailiang; Chen Xiaohua; Li Guozheng

    2002-01-01

    Experiments were done under 252 Cf and 60 Co γ source to study the relation between heavy ion Single Event Upset (SEU) cross sections and γ accumulated doses. There was no obvious rule and little influence of γ accumulated doses on SEU cross sections when Static Random Access Memories were in power off mode and static power on mode. In active measuring mode, the SEU cross section increased as the accumulated doses increasing when same data were written in memory cells. If reverse data, such as '55' and 'AA', were written in memory cells during the experiment, the SEU cross sections decreased to the level when memories were not irradiated under 60 Co γ source, even more small. It implied that the influence of γ accumulated doses on SEU cross sections can be set off by this method

  2. The effect of Cu{sup II} ions in L-asparagine single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Ricardo C., E-mail: santana@ufg.br; Gontijo, Henrique O.; Menezes, Arthur F.; Martins, José A.; Carvalho, Jesiel F., E-mail: carvalho@ufg.br

    2016-11-15

    We report the synthesis, crystal growth, and spectroscopic characterization of L-asparagine monohydrate (LAM) single crystals doped with CuII. The crystals were successfully grown by slow cooling from a supersaturated aqueous solution up to size of 16×12×2 mm{sup 3};the effect of copper impurities in the crystals morphology was discussed. Electron Paramagnetic Resonance (EPR) was used to calculate the g and hyperfine coupling (A) tensors of the CuII ions (g{sub 1}=2.044, g{sub 2}=2.105, g{sub 3}=2.383and A{sub 1}≈0, A{sub 2}=35, A{sub 3}=108 Gauss). The EPR spectra for certain orientations of the magnetic field suggest that CuII ions are coordinated to two {sup 14}N atoms. Correlating the EPR and optical absorption results, the crystal field and the Cu{sup II} orbital bond parameters were calculated. The results indicate that the paramagnetic center occupies interstitial rhombic distorted site and the ground orbital state for the unpaired electron is the d(x{sup 2}-y{sup 2}).

  3. Significantly enhanced visible light response in single TiO2 nanowire by nitrogen ion implantation

    Science.gov (United States)

    Wu, Pengcheng; Song, Xianyin; Si, Shuyao; Ke, Zunjian; Cheng, Li; Li, Wenqing; Xiao, Xiangheng; Jiang, Changzhong

    2018-05-01

    The metal-oxide semiconductor TiO2 shows enormous potential in the field of photoelectric detection; however, UV-light absorption only restricts its widespread application. It is considered that nitrogen doping can improve the visible light absorption of TiO2, but the effect of traditional chemical doping is far from being used for visible light detection. Herein, we dramatically broadened the absorption spectrum of the TiO2 nanowire (NW) by nitrogen ion implantation and apply the N-doped single TiO2 NW to visible light detection for the first time. Moreover, this novel strategy effectively modifies the surface states and thus regulates the height of Schottky barriers at the metal/semiconductor interface, which is crucial to realizing high responsivity and a fast response rate. Under the illumination of a laser with a wavelength of 457 nm, our fabricated photodetector exhibits favorable responsivity (8 A W-1) and a short response time (0.5 s). These results indicate that ion implantation is a promising method in exploring the visible light detection of TiO2.

  4. Fabrication of hydrogel-coated single conical nanochannels exhibiting controllable ion rectification characteristics.

    Science.gov (United States)

    Wang, Linlin; Zhang, Huacheng; Yang, Zhe; Zhou, Jianjun; Wen, Liping; Li, Lin; Jiang, Lei

    2015-03-07

    Heterogeneous nanochannel materials that endow new functionalities different to the intrinsic properties of two original nanoporous materials have wide potential applications in nanofluidics, energy conversion, and biosensors. Herein, we report novel, interesting hydrogel-composited nanochannel devices with regulatable ion rectification characteristics. The heterogeneous nanochannel devices were constructed by selectively coating the tip side, base side, or both sides of a single conical nanochannel membrane with thin agar hydrogel layers. The tunable ion current rectification of the nanochannels in the three different coating states was systematically demonstrated by current-voltage (I-V) curves. The asymmetric ionic transport property of the conical nanochannel was further strengthened in the tip-coating state and weakened in the base-coating state, whereas the conical nanochannel showed nearly symmetric ionic transport in the dual-coating state. Repeated experiments presented insight into the good stability and reversibility of the three coating states of the hydrogel-nanochannel-integrated systems. This work, as an example, may provide a new strategy to further design and develop multifunctional gel-nanochannel heterogeneous smart porous nanomaterials.

  5. Origins of low resistivity in Al ion-implanted ZnO bulk single crystals

    Science.gov (United States)

    Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

    2011-06-01

    The origins of low resistivity in Al ion-implanted ZnO bulk single crystals are studied by combining Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), photoluminescence (PL), and Van der Pauw methods. The Al-ion implantation (peak concentration: 2.6 × 1020cm-3) into ZnO is performed using a multiple-step energy. The resistivity decreases from ˜104 Ω cm for un-implanted ZnO to 1.4 × 10-1 Ω cm for as-implanted, and reaches 6.0 × 10-4 Ω cm for samples annealed at 1000 °C. RBS and NRA measurements for as-implanted ZnO suggest the existence of the lattice displacement of Zn (Zni) and O (Oi), respectively. After annealing at 1000 °C, the Zni related defects remain and the Oi related defects disappear. The origin of the low resistivity in the as-implanted sample is attributed to the Zni (˜30 meV [Look et al., Phys. Rev. Lett. 82, 2552 (1999)]). In contrast, the origin of the low resistivity in the sample annealed at 1000 °C is assigned to both of the Zni related defects and the electrically activated Al donor. A new PL emission appears at around 3.32 eV after annealing at 1000 °C, suggesting electrically activated Al donors.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  7. Lithium-ion Battery Electrothermal Model, Parameter Estimation, and Simulation Environment

    Directory of Open Access Journals (Sweden)

    Simone Orcioni

    2017-03-01

    Full Text Available The market for lithium-ion batteries is growing exponentially. The performance of battery cells is growing due to improving production technology, but market request is growing even more rapidly. Modeling and characterization of single cells and an efficient simulation environment is fundamental for the development of an efficient battery management system. The present work is devoted to defining a novel lumped electrothermal circuit of a single battery cell, the extraction procedure of the parameters of the single cell from experiments, and a simulation environment in SystemC-WMS for the simulation of a battery pack. The electrothermal model of the cell was validated against experimental measurements obtained in a climatic chamber. The model is then used to simulate a 48-cell battery, allowing statistical variations among parameters. The different behaviors of the cells in terms of state of charge, current, voltage, or heat flow rate can be observed in the results of the simulation environment.

  8. Considerations for the Thermal Modeling of Lithium-Ion Cells for Battery Analysis

    DEFF Research Database (Denmark)

    Rickman, Steven L.; Christie, Robert J.; White, Ralph E.

    Recent well-publicized events involving lithium-ion batteries in laptops, electric cars, commercial aircraft and even hover boards have raised concerns regarding thermal runaway -- a phenomenon in which stored energy in a cell is rapidly released as heat along with vented effluents. If not properly...... managed, testing has shown that thermal runaway in a single cell can propagate to other cells in a battery and may lead to a potentially catastrophic event. Lithium-ion batteries are becoming more widely used in a number of human-rated extravehicular activity (EVA) space applications on the International...... Space Station. Thermal modeling in support of thermal runaway propagation mitigation in the Lithium-ion Rechargeable EVA Battery Assembly (LREBA) and the Lithium-on Pistol Grip Tool (LPGT) was pursued to inform design decisions and to understand the results of extensive development testing with the goal...

  9. Review of Parameter Determination for Thermal Modeling of Lithium Ion Batteries

    DEFF Research Database (Denmark)

    Saeed Madani, Seyed; Schaltz, Erik; Kær, Søren Knudsen

    2018-01-01

    This paper reviews different methods for determination of thermal parameters of lithium ion batteries. Lithium ion batteries are extensively employed for various applications owing to their low memory effect, high specific energy, and power density. One of the problems in the expansion of hybrid...... on the lifetime of lithium ion battery cells. Thermal management is critical in electric vehicles (EVs) and good thermal battery models are necessary to design proper heating and cooling systems. Consequently, it is necessary to determine thermal parameters of a single cell, such as internal resistance, specific...... and electric vehicle technology is the management and control of operation temperatures and heat generation. Successful battery thermal management designs can lead to better reliability and performance of hybrid and electric vehicles. Thermal cycling and temperature gradients could have a considerable impact...

  10. Review of Parameter Determination for Thermal Modeling of Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Seyed Saeed Madani

    2018-04-01

    Full Text Available This paper reviews different methods for determination of thermal parameters of lithium ion batteries. Lithium ion batteries are extensively employed for various applications owing to their low memory effect, high specific energy, and power density. One of the problems in the expansion of hybrid and electric vehicle technology is the management and control of operation temperatures and heat generation. Successful battery thermal management designs can lead to better reliability and performance of hybrid and electric vehicles. Thermal cycling and temperature gradients could have a considerable impact on the lifetime of lithium ion battery cells. Thermal management is critical in electric vehicles (EVs and good thermal battery models are necessary to design proper heating and cooling systems. Consequently, it is necessary to determine thermal parameters of a single cell, such as internal resistance, specific heat capacity, entropic heat coefficient, and thermal conductivity in order to design suitable thermal management system.

  11. Ion-atom collisions with laser-prepared target: High resolution study of single charge exchange process

    International Nuclear Information System (INIS)

    Leredde, Arnaud

    2012-01-01

    Single charge transfer in low-energy Na"++"8"7Rb(5s,5p) collisions is investigated using magneto-optically trapped Rb atoms and high-resolution recoil-ion momentum spectroscopy. The three-dimensional reconstruction of the recoil-ion momentum provides accurate relative cross-sections for the active channels and the projectile scattering angle distributions. Thanks to the high experimental resolution, scattering structures such as diffraction-like oscillations in angular distributions are clearly observed. The measurements are compared with molecular close-coupling calculations and an excellent agreement is found. To go further in the test of the theory, the target is prepared in an oriented state. It is the first time that such collision experiments with oriented target is performed with such a high resolution. The right-left asymmetry expected for the scattering angle distribution is evidenced. The agreement between MOCC calculations and experiments is very good. Simple models developed for collisions with oriented target are also discussed. (author) [fr

  12. A Simple Analytical Model for Predicting the Detectable Ion Current in Ion Mobility Spectrometry Using Corona Discharge Ionization Sources

    Science.gov (United States)

    Kirk, Ansgar Thomas; Kobelt, Tim; Spehlbrink, Hauke; Zimmermann, Stefan

    2018-05-01

    Corona discharge ionization sources are often used in ion mobility spectrometers (IMS) when a non-radioactive ion source with high ion currents is required. Typically, the corona discharge is followed by a reaction region where analyte ions are formed from the reactant ions. In this work, we present a simple yet sufficiently accurate model for predicting the ion current available at the end of this reaction region when operating at reduced pressure as in High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) or most IMS-MS instruments. It yields excellent qualitative agreement with measurement results and is even able to calculate the ion current within an error of 15%. Additional interesting findings of this model are the ion current at the end of the reaction region being independent from the ion current generated by the corona discharge and the ion current in High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) growing quadratically when scaling down the length of the reaction region. [Figure not available: see fulltext.

  13. Transferability of polarizable models for ion-water electrostatic interaction

    International Nuclear Information System (INIS)

    Masia, Marco

    2009-01-01

    Studies of ion-water systems at condensed phase and at interfaces have pointed out that molecular and ionic polarization plays an important role for many phenomena ranging from hydrogen bond dynamics to water interfaces' structure. Classical and ab initio Molecular Dynamics simulations reveal that induced dipole moments at interfaces (e.g. air-water and water-protein) are usually high, hinting that polarizable models to be implemented in classical force fields should be very accurate in reproducing the electrostatic properties of the system. In this paper the electrostatic properties of three classical polarizable models for ion-water interaction are compared with ab initio results both at gas and condensed phase. For Li + - water and Cl - -water dimers the reproducibility of total dipole moments obtained with high level quantum chemical calculations is studied; for the same ions in liquid water, Car-Parrinello Molecular Dynamics simulations are used to compute the time evolution of ionic and molecular dipole moments, which are compared with the classical models. The PD2-H2O model developed by the author and coworkers [Masia et al. J. Chem. Phys. 2004, 121, 7362] together with the gaussian intermolecular damping for ion-water interaction [Masia et al. J. Chem. Phys. 2005, 123, 164505] showed to be the fittest in reproducing the ab initio results from gas to condensed phase, allowing for force field transferability.

  14. Influence of strong single-ion anisotropy on phase states of 3D and 2D frustrated magnets

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Kosmachev, O.A.; Matunin, D.A.; Gorelikov, G.A.; Klevets, Ph.N.

    2010-01-01

    We investigated the influence of strong single-ion anisotropy, exceeding exchange interaction, and frustrated exchange interaction on spin-wave excitation spectra and phase states using the Hubbard operators' technique, allowing the exact account of single-ion anisotropy. The results show that both the homogeneous phases (ferromagnetic and quadrupolar) and the spatially inhomogeneous phase (spiral structure) are possible in the 3D magnetic crystal. The region of existence of the spiral structure is considerably smaller than that in the analogues system, but with weak single-ion anisotropy. The situation is more complex in the 2D system; another spatially inhomogeneous state (the domain structure) can be realized in addition to the spiral magnetic structure. The phase diagrams for both the 3D and 2D systems were plotted.

  15. Self-supporting film method of silicon single crystal by ion implantation and it`s application

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kazuo; Nakao, Setsuo; Niwa, Hiroaki; Miyagawa, Soji [National Industrial Research Inst. of Nagoya (Japan)

    1996-12-01

    A few {mu}m of thickness of self-supporting film of silicon single crystal was produced by the ion implantation and the selective etching. This materials are distinguished by a uniform film thickness, good controllability, crystallization and the mechanical strength. For applying it to device, the detailed process has to be established, because there are some improved problems such as pinhole and morphology on the surface. This materials are very useful to the basic experiment of the base for epitaxial growth under irradiation of ion beams and the ion beam analysis in the atmosphere. (S.Y.)

  16. Investigation of the alpha cluster model and the density matrix expansion in ion-ion collision

    International Nuclear Information System (INIS)

    Rashdan, M.B.M.

    1986-01-01

    This thesis deals with the investigation of the alpha cluster model (ACM) of brink and studies of the accuracy of the density matrix expansion (DME) approximation in deriving the real part of the ion-ion optical potential. the ACM is applied to calculate the inelastic 0 1 + →2 1 + charge form factor for electron scattering by 12 C to investigate the validity of this model for 12 C nucleus. it is found that the experimental curve can be fitted over the entire range of the momentum transfer by a generator - coordinate state for the 2 1 + state that consist of a superposition of two triangular ACM states with two different cluster separations and the same oscillator parameter

  17. A lattice-gas model of the ion current across the solid interface: fast-ion conductor - intercalate

    International Nuclear Information System (INIS)

    Nachev, I.; Balkanski, M.

    1994-12-01

    The transport of Lithium ions across the material interface: fast-ion conducting glass - intercalate is simulated by a non-trivial lattice-gas model. The model takes explicitly into account the influence of the Coulomb correlations, the site-blocking effect and the boundary conditions on the ion kinetics. Potential device applications of the model are pointed out by computing the current density of Lithium ions for material parameters of the real interface: doped ternary borate glass - Indium Selenide, which constitute the electrolyte and the cathode, respectively, of a thin-film microbattery with improved performance. (author). 10 refs, 4 figs

  18. Predictive Models of Li-ion Battery Lifetime (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G.; Shi, Y.; Pesaran, A.

    2014-09-01

    Predictive models of Li-ion battery reliability must consider a multiplicity of electrochemical, thermal and mechanical degradation modes experienced by batteries in application environments. Complicating matters, Li-ion batteries can experience several path dependent degradation trajectories dependent on storage and cycling history of the application environment. Rates of degradation are controlled by factors such as temperature history, electrochemical operating window, and charge/discharge rate. Lacking accurate models and tests, lifetime uncertainty must be absorbed by overdesign and warranty costs. Degradation models are needed that predict lifetime more accurately and with less test data. Models should also provide engineering feedback for next generation battery designs. This presentation reviews both multi-dimensional physical models and simpler, lumped surrogate models of battery electrochemical and mechanical degradation. Models are compared with cell- and pack-level aging data from commercial Li-ion chemistries. The analysis elucidates the relative importance of electrochemical and mechanical stress-induced degradation mechanisms in real-world operating environments. Opportunities for extending the lifetime of commercial battery systems are explored.

  19. Ion-reversibility studies in amorphous solids using the two-atom scattering model

    International Nuclear Information System (INIS)

    Oen, O.S.

    1981-06-01

    An analytical two-atom scattering model has been developed to treat the recent discovery of the enhancement near 180 0 of Rutherford backscattering yields from disordered solids. In contrast to conventional calculations of Rutherford backscattering that treat scattering from a single atom only (the backscattering atom), the present model includes the interaction of a second atom lying between the target surface and the backscattering plane. The projectile ion makes a glancing collision with this second atom both before and after it is backscattered. The model predicts an enhancement effect whose physical origin arises from the tolerance of path for those ions whose inward and outward trajectories lie in the vicinity of the critical impact parameter. Results using Moliere scattering show how the yield enhancement depends on ion energy, backscattering depth, exit angle, scattering potential, atomic numbers of the projectile and target, and target density. In the model the critical impact parameter and critical angle play important roles. It is shown that these quantities depend on a single dimensionless parameter and analytical expressions for them are given which are accurate to better than 1%

  20. Ion mobilities in diatomic gases: measurement versus prediction with non-specular scattering models.

    Science.gov (United States)

    Larriba, Carlos; Hogan, Christopher J

    2013-05-16

    compact to highly linear, and singly charged tetraalkylammonium cations. It was found that both non-specular, inelastic scattering rules lead to excellent agreement between predictions and experimental mobility measurements (within 5% of each other) and that polarization potentials must be considered to make correct predictions for high-mobility particles/ions. Conversely, traditional specular, elastic scattering models were found to substantially overestimate the mobilities of both types of ions.

  1. Homogenized modeling methodology for 18650 lithium-ion battery module under large deformation

    Science.gov (United States)

    Tang, Liang; Cheng, Pengle

    2017-01-01

    Effective lithium-ion battery module modeling has become a bottleneck for full-size electric vehicle crash safety numerical simulation. Modeling every single cell in detail would be costly. However, computational accuracy could be lost if the module is modeled by using a simple bulk material or rigid body. To solve this critical engineering problem, a general method to establish a computational homogenized model for the cylindrical battery module is proposed. A single battery cell model is developed and validated through radial compression and bending experiments. To analyze the homogenized mechanical properties of the module, a representative unit cell (RUC) is extracted with the periodic boundary condition applied on it. An elastic–plastic constitutive model is established to describe the computational homogenized model for the module. Two typical packing modes, i.e., cubic dense packing and hexagonal packing for the homogenized equivalent battery module (EBM) model, are targeted for validation compression tests, as well as the models with detailed single cell description. Further, the homogenized EBM model is confirmed to agree reasonably well with the detailed battery module (DBM) model for different packing modes with a length scale of up to 15 × 15 cells and 12% deformation where the short circuit takes place. The suggested homogenized model for battery module makes way for battery module and pack safety evaluation for full-size electric vehicle crashworthiness analysis. PMID:28746390

  2. Homogenized modeling methodology for 18650 lithium-ion battery module under large deformation.

    Directory of Open Access Journals (Sweden)

    Liang Tang

    Full Text Available Effective lithium-ion battery module modeling has become a bottleneck for full-size electric vehicle crash safety numerical simulation. Modeling every single cell in detail would be costly. However, computational accuracy could be lost if the module is modeled by using a simple bulk material or rigid body. To solve this critical engineering problem, a general method to establish a computational homogenized model for the cylindrical battery module is proposed. A single battery cell model is developed and validated through radial compression and bending experiments. To analyze the homogenized mechanical properties of the module, a representative unit cell (RUC is extracted with the periodic boundary condition applied on it. An elastic-plastic constitutive model is established to describe the computational homogenized model for the module. Two typical packing modes, i.e., cubic dense packing and hexagonal packing for the homogenized equivalent battery module (EBM model, are targeted for validation compression tests, as well as the models with detailed single cell description. Further, the homogenized EBM model is confirmed to agree reasonably well with the detailed battery module (DBM model for different packing modes with a length scale of up to 15 × 15 cells and 12% deformation where the short circuit takes place. The suggested homogenized model for battery module makes way for battery module and pack safety evaluation for full-size electric vehicle crashworthiness analysis.

  3. Characterization and modeling of the thermal mechanics of lithium-ion battery cells

    International Nuclear Information System (INIS)

    Oh, Ki-Yong; Epureanu, Bogdan I.

    2016-01-01

    Highlights: • Thermal swelling shape is different than Li-ion intercalation swelling shape. • Nonuniform temperature and gap creation leads to a convex shape at free conditions. • Important parameters of thermal mechanics are estimated through experiments. • A coupled thermal-structural analysis accurately predicts thermal swelling shape. • Nonuniform temperature still plays a critical role at pack conditions. - Abstract: The thermal mechanics of Lithium-ion (Li-ion) batteries is explored with a focus on thermal swelling. Experiments show for the first time that the swelling shape of prismatic battery cells due to temperature variations is significantly different from that due to Li-ion intercalation in unconstrained conditions. In contrast to uniform and orthotropic Li-ion intercalation swelling in a direction perpendicular to electrodes, the nonuniform temperature distribution in the jellyroll and the gaps/voids between electrodes result in distinguishable different swelling shapes. A unique coupled thermal-structural analysis with a simple, but efficient 3-D finite numerical model is proposed to investigate the impact of temperature variations on the thermal behaviors of battery cells. Anisotropic heat conduction and temperature dependency of the coefficient of thermal expansion are taken into account and found to have an impact on temperature distribution and thermal expansion. Experimental validation of the proposed model clearly demonstrates that the coupled thermal-structural analysis with the proposed model can predict accurately the thermal swelling at unconstrained conditions. The solution at pack (constrained) conditions shows that the nonuniform temperature distribution of the jellyroll still plays a critical role for the thermal swelling shape, although the gaps/voids do not occur because of the constraints from spacers in the pack, suggesting that the estimation of core temperature is important. Such an accurate model, able to estimate cell

  4. Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Mohd F., E-mail: faisalt@petronas.com.my; Shaharun, Maizatul S. [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia); Shuib, Anis Suhaila, E-mail: anisuha@petronas.com.my; Borhan, Azry [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia)

    2014-10-24

    An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m{sup 2}/g and 0.17 cm{sup 2}/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution were carried out at a fixed initial concentration of metal ion (150 ppm) with variation amount of adsorbent (rice husk-based activated carbon) as a function of varied contact time at room temperature. The concentration of each metal ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Isotherm and kinetic model analyses suggested that the experimental data of adsorption studies fitted well with Langmuir, Freundlich and second-order kinetic models.

  5. Particle modeling of transport of α-ray generated ion clusters in air

    International Nuclear Information System (INIS)

    Tong, Lizhu; Nanbu, Kenichi; Hirata, Yosuke; Izumi, Mikio; Miyamoto, Yasuaki; Yamaguchi, Hiromi

    2006-01-01

    A particle model is developed using the test-particle Monte Carlo method to study the transport properties of α-ray generated ion clusters in a flow of air. An efficient ion-molecule collision model is proposed to simulate the collisions between ion and air molecule. The simulations are performed for a steady state of ion transport in a circular pipe. In the steady state, generation of ions is balanced with such losses of ions as absorption of the measuring sensor or pipe wall and disappearance by positive-negative ion recombination. The calculated ion current to the measuring sensor agrees well with the previous measured data. (author)

  6. Fractional Poisson-Nernst-Planck Model for Ion Channels I: Basic Formulations and Algorithms.

    Science.gov (United States)

    Chen, Duan

    2017-11-01

    In this work, we propose a fractional Poisson-Nernst-Planck model to describe ion permeation in gated ion channels. Due to the intrinsic conformational changes, crowdedness in narrow channel pores, binding and trapping introduced by functioning units of channel proteins, ionic transport in the channel exhibits a power-law-like anomalous diffusion dynamics. We start from continuous-time random walk model for a single ion and use a long-tailed density distribution function for the particle jump waiting time, to derive the fractional Fokker-Planck equation. Then, it is generalized to the macroscopic fractional Poisson-Nernst-Planck model for ionic concentrations. Necessary computational algorithms are designed to implement numerical simulations for the proposed model, and the dynamics of gating current is investigated. Numerical simulations show that the fractional PNP model provides a more qualitatively reasonable match to the profile of gating currents from experimental observations. Meanwhile, the proposed model motivates new challenges in terms of mathematical modeling and computations.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

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

  9. An induction Linac driven heavy-ion fusion systems model

    International Nuclear Information System (INIS)

    Zuckerman, D.S.; Driemeyer, D.E.; Waganer, L.M.; Dudziak, D.J.

    1988-01-01

    A computerized systems model of a heavy-ion fusion (HIF) reactor power plant is presented. The model can be used to analyze the behavior and projected costs of a commercial power plant using an induction linear accelerator (Linac) as a driver. Each major component of the model (targets, reactor cavity, Linac, beam transport, power flow, balance of plant, and costing) is discussed. Various target, reactor cavity, Linac, and beam transport schemes are examined and compared. The preferred operating regime for such a power plant is also examined. The results show that HIF power plants can compete with other advanced energy concepts at the 1000-MW (electric) power level [cost of electricity (COE) -- 50 mill/kW . h] provided that the cost savings predicted for Linacs using higher charge-state ions (+3) can be realized

  10. Softening the ultra-stiff: Controlled variation of Young’s modulus in single-crystal diamond by ion implantation

    International Nuclear Information System (INIS)

    Battiato, A.; Lorusso, M.; Bernardi, E.; Picollo, F.; Bosia, F.; Ugues, D.; Zelferino, A.; Damin, A.; Baima, J.

    2016-01-01

    A combined experimental and numerical study on the variation of the elastic properties of defective single-crystal diamond is presented for the first time, by comparing nano-indentation measurements on MeV-ion-implanted samples with multi-scale modeling consisting of both ab initio atomistic calculations and meso-scale Finite Element Method (FEM) simulations. It is found that by locally introducing defects in the 2 × 10 18 –5 × 10 21  cm −3 density range, a significant reduction of Young’s modulus, as well as of density, can be induced in the diamond crystal structure without incurring in the graphitization of the material. Ab initio atomistic simulations confirm the experimental findings with a good degree of confidence. FEM simulations are further employed to verify the consistency of measured deformations with a stiffness reduction, and to derive strain and stress levels in the implanted region. Combining these experimental and numerical results, we also provide insight into the mechanism responsible for the depth dependence of the graphitization threshold in diamond. This work prospects the possibility of achieving accurate tunability of the mechanical properties of single-crystal diamond through defect engineering, with significant technological applications, e.g. the fabrication and control of the resonant frequency of diamond-based micromechanical resonators.

  11. Control oriented 1D electrochemical model of lithium ion battery

    International Nuclear Information System (INIS)

    Smith, Kandler A.; Rahn, Christopher D.; Wang, Chao-Yang

    2007-01-01

    Lithium ion (Li-ion) batteries provide high energy and power density energy storage for diverse applications ranging from cell phones to hybrid electric vehicles (HEVs). For efficient and reliable systems integration, low order dynamic battery models are needed. This paper introduces a general method to generate numerically a fully observable/controllable state variable model from electrochemical kinetic, species and charge partial differential equations that govern the discharge/charge behavior of a Li-ion battery. Validated against a 313th order nonlinear CFD model of a 6 Ah HEV cell, a 12th order state variable model predicts terminal voltage to within 1% for pulse and constant current profiles at rates up to 50 C. The state equation is constructed in modal form with constant negative real eigenvalues distributed in frequency space from 0 to 10 Hz. Open circuit potential, electrode surface concentration/reaction distribution coupling and electrolyte concentration/ionic conductivity nonlinearities are explicitly approximated in the model output equation on a local, electrode-averaged and distributed basis, respectively. The balanced realization controllability/observability gramian indicates that the fast electrode surface concentration dynamics are more observable/controllable than the electrode bulk concentration dynamics (i.e. state of charge)

  12. Irradiation of zinc single crystal with 500 keV singly-charged carbon ions: surface morphology, structure, hardness, and chemical modifications

    Science.gov (United States)

    Waqas Khaliq, M.; Butt, M. Z.; Saleem, Murtaza

    2017-07-01

    Cylindrical specimens of (1 0 4) oriented zinc single crystal (diameter  =  6 mm and length  =  5 mm) were irradiated with 500 keV C+1 ions with the help of a Pelletron accelerator. Six specimens were irradiated in an ultra-high vacuum (~10‒8 Torr) with different ion doses, namely 3.94  ×  1014, 3.24  ×  1015, 5.33  ×  1015, 7.52  ×  1015, 1.06  ×  1016, and 1.30  ×  1016 ions cm-2. A field emission scanning electron microscope (FESEM) was utilized for the morphological study of the irradiated specimens. Formation of nano- and sub-micron size rods, clusters, flower- and fork-like structures, etc, was observed. Surface roughness of the irradiated specimens showed an increasing trend with the ions dose. Energy dispersive x-ray spectroscopy (EDX) helped to determine chemical modifications in the specimens. It was found that carbon content varied in the range 22.86-31.20 wt.% and that oxygen content was almost constant, with an average value of 10.16 wt.%. The balance content was zinc. Structural parameters, i.e. crystallite size and lattice strain, were determined by Williamson-Hall analysis using x-ray diffraction (XRD) patterns of the irradiated specimens. Both crystallite size and lattice strain showed a decreasing trend with the increasing ions dose. A good linear relationship between crystallite size and lattice strain was observed. Surface hardness depicted a decreasing trend with the ions dose and followed an inverse Hall-Petch relation. FTIR spectra of the specimens revealed that absorption bands gradually diminish as the dose of singly-charged carbon ions is increased from 3.94  ×  1014 ions cm-1 to 1.30  ×  1016 ions cm-1. This indicates progressive deterioration of chemical bonds with the increase in ion dose.

  13. Development of the balance equations model for calculation of ion charge-state distribution in ECR ion sources

    International Nuclear Information System (INIS)

    Filippov, A.V.; Shirkov, G.D.; Consoli, F.; Gammino, S.; Ciavola, G.; Celona, L.; Barbarino, S.

    2008-01-01

    The investigation of the widespread model for the calculation of ion charge-state distributions (CSD) in electron cyclotron-resonance ion source based on the set of balance equations is given. The modification of this model that allows one to describe the confinement and accumulation processes of highly charged ions in ECR plasma for gas mixing case more precisely is discussed. The new approach for the time confinement calculation (ions and electrons) based on the theory of Pastukhov is offered, viz. - calculation of confinement times during two step minimization of special type functionals. The results obtained by this approach have been compared with available experimental data

  14. A single product perishing inventory model with demand interaction

    African Journals Online (AJOL)

    The paper describes a single perishing product inventory model in which ... continuous review inventory models have been studied recently by Yadavalli et al ...... stochastic inventory system with lost sales, Stochastic Analysis and Applications ...

  15. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Borràs, S. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Kaufmann, A., E-mail: anton.kaufmann@klzh.ch [Official Food Control Authority, Fehrenstrasse 15, 8032 Zürich (Switzerland); Companyó, R. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain)

    2013-04-15

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed.

  16. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    International Nuclear Information System (INIS)

    Borràs, S.; Kaufmann, A.; Companyó, R.

    2013-01-01

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed

  17. Synchrotron Topographic and Diffractometer Studies of Buried Layered Structures Obtained by Implantation with Swift Heavy Ions in Silicon Single Crystals

    International Nuclear Information System (INIS)

    Wierzchowski, W.; Wieteska, K.; Zymierska, D.; Graeff, W.; Czosnyka, T.; Choinski, J.

    2006-01-01

    A distribution of crystallographic defects and deformation in silicon crystals subjected to deep implantation (20-50 μm) with ions of the energy of a few MeV/amu is studied. Three different buried layered structures (single layer, binary buried structure and triple buried structure) were obtained by implantation of silicon single crystals with 184 MeV argon ions, 29.7 MeV boron ions, and 140 MeV argon ions, each implantation at a fluency of 1x10 14 ions cm -2 . The implanted samples were examined by means of white beam X-ray section and projection topography, monochromatic beam topography and by recording local rocking curves with the beam restricted to 50 x 50 μm 2 . The experiment pointed to a very low level of implantation-induced strain (below 10 -5 ). The white beam Bragg case section experiment revealed a layer producing district black contrast located at a depth of the expected mean ion range. The presence of these buried layered structures in studied silicon crystals strongly affected the fringe pattern caused by curvature of the samples. In case of white beam projection and monochromatic beam topographs the implanted areas were revealed as darker regions with a very tiny grain like structure. One may interpret these results as the effect of considerable heating causing annihilation of point defects and formation of dislocation loops connected with point defect clusters. (author)

  18. Electron impact ionization of B-like ion N2+. Resonance enhancement of the single-channel cross section

    International Nuclear Information System (INIS)

    Li Guohe; Qian Xingzhong; Pan Soufu

    1998-01-01

    The electron impact ionization cross sections of B-like ion N 2+ are calculated in the Coulomb-Born no exchange approximation by using R-matrix method, and the single differential cross section is given. The calculated results exhibit the Rydberg series of resonances. The resonance enhancement of the single-channel cross section is significantly greater than direct ionization cross section. It is agreement with that of Chidichimo

  19. Single-cluster dynamics for the random-cluster model

    NARCIS (Netherlands)

    Deng, Y.; Qian, X.; Blöte, H.W.J.

    2009-01-01

    We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to noninteger values q>1. Its results for static quantities are in a satisfactory agreement with those

  20. An Online SOC and SOH Estimation Model for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Shyh-Chin Huang

    2017-04-01

    Full Text Available The monitoring and prognosis of cell degradation in lithium-ion (Li-ion batteries are essential for assuring the reliability and safety of electric and hybrid vehicles. This paper aims to develop a reliable and accurate model for online, simultaneous state-of-charge (SOC and state-of-health (SOH estimations of Li-ion batteries. Through the analysis of battery cycle-life test data, the instantaneous discharging voltage (V and its unit time voltage drop, V′, are proposed as the model parameters for the SOC equation. The SOH equation is found to have a linear relationship with 1/V′ times the modification factor, which is a function of SOC. Four batteries are tested in the laboratory, and the data are regressed for the model coefficients. The results show that the model built upon the data from one single cell is able to estimate the SOC and SOH of the three other cells within a 5% error bound. The derived model is also proven to be robust. A random sampling test to simulate the online real-time SOC and SOH estimation proves that this model is accurate and can be potentially used in an electric vehicle battery management system (BMS.

  1. The nature of single-ion activity coefficients calculated from potentiometric measurements on cells with liquid junctions

    Energy Technology Data Exchange (ETDEWEB)

    Zarubin, Dmitri P., E-mail: dmitri.zarubin@mtu-net.ru [Department of Physical and Collod Chemistry, Moscow State University of Technology and Management, 73 Zemlyanoi Val, Moscow 109803 (Russian Federation)

    2011-08-15

    Highlights: > Problem of ionic activity coefficients, determined by potentiometry, is reconsidered. > They are found to be functions of mean activity coefficients and transport numbers of ions. > The finding is verified by calculations and comparing the results with reported data. > Calculations are performed for systems with single electrolytes and binary mixtures. - Abstract: Potentiometric measurements on cells with liquid junctions are sometimes used for calculations of single-ion activity coefficients in electrolyte solutions, the incidence of this being increased recently. As surmised by Guggenheim in the 1930s, such coefficients (of ions i), {gamma}{sub i}, are actually complicated functions of mean ionic activity coefficients, {gamma}{sub {+-}}, and transport numbers of ions, t{sub i}. In the present paper specific functions {gamma}{sub i}({gamma}{sub {+-}}, t{sub i}) are derived for a number of cell types with an arbitrary mixture of strong electrolytes in a one-component solvent in the liquid-junction system. The cell types include cells with (i) identical electrodes, (ii) dissimilar electrodes reversible to the same ions, (iii) dissimilar electrodes reversible to ions of opposite charge signs, (iv) dissimilar electrodes reversible to different ions of the same charge sign, and (v) identical reference electrodes and an ion-selective membrane permeable to ions of only one type. Pairs of functions for oppositely charged ions are found to be consistent with the mean ionic activity coefficients as would be expected for pairs of the proper {gamma}{sub i} quantities by definition of {gamma}{sub {+-}}. The functions are tested numerically on some of the reported {gamma}{sub i} datasets that are the more tractable. A generally good agreement is found with data reported for cells with single electrolytes HCl and KCl in solutions, and with binary mixtures in the liquid-junction systems of KCl from the reference solutions and NaCl and HCl from the test solutions. It

  2. Monte Carlo simulation of boron-ion implantation into single-crystal silicon

    International Nuclear Information System (INIS)

    Klein, K.M.

    1991-01-01

    A physically based Monte Carlo boron implantation model developed comprehends previously neglected but important implant parameters such as native oxide layers, wafer temperature, beam divergence, tilt angle, rotation (twist) angle, and dose, in addition to energy. This model uses as its foundation the MARLOWE Monte Carlo simulation code developed at Oak Ridge National Laboratory for the analysis of radiation effects in materials. This code was carefully adapted for the simulation of ion implantation, and a number of significant improvements have been made, including the addition of atomic pair specific interatomic potentials, the implementation of a newly developed local electron concentration dependent electronic stopping model, and the implementation of a newly developed cumulative damage model. This improved version of the code, known as UT-MARLOWE, allows boron implantation profiles to be accurately predicted as a function of energy, tilt angle, rotation angle, and dose. This code has also been used in the development and implementation of an accurate and efficient two-dimensional boron implantation model

  3. Mechanical characterization of magnesium aluminate MgO·nAl2O3 spinel single crystals irradiated with Cu- ions

    International Nuclear Information System (INIS)

    Ohmura, Takahito; Lee, Chi-Gyu; Kishimoto, Naoki

    2003-01-01

    Ion-irradiation response of spinel single crystals was investigated using a nanoindentation technique. Specimens of stoichiometric (n=1) and non-stoichiometric (n=2.4) single crystals of MgO n(Al 2 O 3 ) spinel were irradiated with 60 keV Cu - ion at room temperature. Dose rate ranged from 1 to 100 μA/cm 2 , and a total dose was kept constant at 3x10 16 ions/cm 2 . Both plastic hardness and elastic modulus of all the irradiated specimens were softened. Radiation-induced swelling simultaneously occurred. Rutherford back scattering spectroscopy detected disordering of spinel crystalline structure. Accordingly, the radiation-induced softening and swelling are ascribed to accumulation of point defects associated with the disordering. In comparison between the stoichiometric and the non-stoichiometric specimens, the radiation-induced softening is suppressed in the non-stoichiometric composition. (author)

  4. Modelling interaction cross sections for intermediate and low energy ions

    International Nuclear Information System (INIS)

    Toburen, L.H.; Shinpaugh, J.L.; Justiniano, E.L.B.

    2002-01-01

    When charged particles slow in tissue they undergo electron capture and loss processes than can have profound effects on subsequent interaction cross sections. Although a large amount of data exists for the interaction of bare charged particles with atoms and molecules, few experiments have been reported for these 'dressed' particles. Projectile electrons contribute to an impact-parameter-dependent screening of the projectile charge that precludes straightforward scaling of energy loss cross sections from those of bare charged particles. The objective of this work is to develop an analytical model for the energy-loss-dependent effects of screening on differential ionisation cross sections that can be used in track structure calculations for high LET ions. As a first step a model of differential ionisation cross sections for bare ions has been combined with a simple screening model to explore cross sections for intermediate and low energy dressed ions in collisions with atomic and molecular gas targets. The model is described briefly and preliminary results compared to measured electron energy spectra. (author)

  5. Luminescence properties of Tm3+ ions single-doped YF3 materials in an unconventional excitation region.

    Science.gov (United States)

    Chen, Yuan; Liu, Qing; Lin, Han; Yan, Xiaohong

    2018-05-01

    According to the spectral distribution of solar radiation at the earth's surface, under the excitation region of 1150 to 1350 nm, the up-conversion luminescence of Tm 3+ ions was investigated. The emission bands were matched well with the spectral response region of silicon solar cells, achieved by Tm 3+ ions single-doped yttrium fluoride (YF 3 ) phosphor, which was different from the conventional Tm 3+ /Yb 3+ ion couple co-doped materials. Additionally, the similar emission bands of Tm 3+ ions were achieved under excitation in the ultraviolet region. It is expected that via up-conversion and down-conversion routes, Tm 3+ -sensitized materials could convert photons to the desired wavelengths in order to reduce the energy loss of silicon solar cells, thereby enhancing the photovoltaic efficiency. Copyright © 2018 John Wiley & Sons, Ltd.

  6. Collisions of singly and doubly charged ions with oxygen molecules in the energy range 1 - 1800 (3600) eV

    International Nuclear Information System (INIS)

    Kuen, I.; Howorka, F.

    1983-01-01

    Absolute cross sections for the excitation of optically emitting states in collisions of He + , Ne + , Ar + , Kr + , B + , He ++ , Ne ++ and Ar ++ with oxygen molecules are measured, the energy range of the ion being1 - 1800 eV Lab for the singly charged and 1 - 3600 eV for the doubly charged ions. Seven important processes can be distinguished: charge exchange excitation of O 2 + band, O I, O II, X I and X II lines (X + , X ++ being the primary ion), direct excitation of X II and double charge exchange excitations. The energy dependences of the excitation cross sections are remarkably different for different processes but similar for one process with different ions. The sum total of all cross sections together for excitations which lead to light emission is on the order of a few square angstroms at 1000 eV c.m. energy. The results are of interest for surface investigations, plasma diagnostics and laser work. (Author)

  7. Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

    International Nuclear Information System (INIS)

    Sakamoto, Y.; Ishii, Y.; Kawasaki, S.

    2016-01-01

    Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

  8. Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Y.; Ishii, Y.; Kawasaki, S., E-mail: kawasaki.shinji@nitech.ac.jp [Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi (Japan)

    2016-07-06

    Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

  9. Effects of ion strength and ion pairing on (plant-wide) modelling of anaerobic digestion processes

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Mbamba, Christian Kazadi; Solon, Kimberly

    2014-01-01

    the effects that an improved physico-chemical description will have on the predicted effluent quality (EQI) and operational cost (OCI) indices. The acid-base equilibria implemented in the Anaerobic Digestion Model No.1 (ADM1) are modified to account for non-ideal aqueous-phase chemistry. The model corrects......The objective of this study is to show the influence of ionic strength (as activity corrections) andion pairing on (plant-wide) modelling of anaerobic digestion processes in wastewater treatment plants(WWTPs). Using the Benchmark Simulation Model No. 2 (BSM2) as a case study, this paper presents...... for ionic strength via the Davies approach to consider chemical activities instead of molar concentrations. Also, a speciation sub-routine based on a multi-dimensional Newton-Raphson iteration method accounts for the formation of some of the ion pairs playing an important role in wastewater treatment...

  10. Colour rope model for extreme relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Biro, T.S.; Nielsen, H.B.; Knoll, J.

    1984-04-01

    Our goal is to investigate the possible cumulative effects of the colour fields of the observable meson multiplicity distribution in the central rapidity region in extreme relativistic heavy ion collisions. In the first Chapter we overview the space-time picture of the string formation in a central heavy ion collision. We take into account trivial geometrical factors in a straight line geometry. In the second Chapter we consider the colour chargation process of heavy ions as a random walk. We calculate the expectation value and the relative standard deviation of the total effective charge square. In the third Chapter we consider the stochastic decay of a K-fold string-rope to mesons by the Schwinger-mechanism. We calculate the expected lifetime of a K-fold string and the time for the first quark antiquark pair creation. In the fourth Chapter we deal with the meson production of a K-fold rope relative to that of a single string and hence we look for a scaling between A + A and p + p collisions. (orig./HSI)

  11. Artificial neural network modelling in heavy ion collisions

    International Nuclear Information System (INIS)

    El-dahshan, E.; Radi, A.; El-Bakry, M.Y.; El Mashad, M.

    2008-01-01

    The neural network (NN) model and parton two fireball model (PTFM) have been used to study the pseudo-rapidity distribution of the shower particles for C 12, O 16, Si 28 and S 32 on nuclear emulsion. The trained NN shows a better fitting with experimental data than the PTFM calculations. The NN is then used to predict the distributions that are not present in the training set and matched them effectively. The NN simulation results prove a strong presence modeling in heavy ion collisions

  12. The WARP Code: Modeling High Intensity Ion Beams

    International Nuclear Information System (INIS)

    Grote, David P.; Friedman, Alex; Vay, Jean-Luc; Haber, Irving

    2005-01-01

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand

  13. The WARP Code: Modeling High Intensity Ion Beams

    International Nuclear Information System (INIS)

    Grote, D P; Friedman, A; Vay, J L; Haber, I

    2004-01-01

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand. Additional information can be found on the web page http://hif.lbl.gov/theory/WARP( ) summary.html

  14. Single-layer model for surface roughness.

    Science.gov (United States)

    Carniglia, C K; Jensen, D G

    2002-06-01

    Random roughness of an optical surface reduces its specular reflectance and transmittance by the scattering of light. The reduction in reflectance can be modeled by a homogeneous layer on the surface if the refractive index of the layer is intermediate to the indices of the media on either side of the surface. Such a layer predicts an increase in the transmittance of the surface and therefore does not provide a valid model for the effects of scatter on the transmittance. Adding a small amount of absorption to the layer provides a model that predicts a reduction in both reflectance and transmittance. The absorbing layer model agrees with the predictions of a scalar scattering theory for a layer with a thickness that is twice the rms roughness of the surface. The extinction coefficient k for the layer is proportional to the thickness of the layer.

  15. A model for high-energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Myers, W.D.

    1978-01-01

    A model is developed for high-energy heavy-ion collisions that treats the variation across the overlap region of the target and projectile in the amount of energy and momentum that is deposited. The expression for calculating any observable takes the form of a sum over a series of terms, each one of which consists of a geometric, a kinematic, and a statistical factor. The geometrical factors for a number of target projectile systems are tabulated. (Auth.)

  16. Comparison of models of high energy heavy ion collision

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1977-01-01

    Some of the main theoretical developments on heavy ion collisions at energies (0.1 to 2.0) GeV/nuc are reviewed. The fireball, firestreak, hydrodynamic (1-fluid, 2-fluids), ''row on row'', hard sphere and intranuclear cascades, and classical equations of motion models are discussed in detail. Results are compared to each other and to measured Ne + U → p + X reactions

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-15

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

  18. Monte Carlo modeling of ion chamber performance using MCNP.

    Science.gov (United States)

    Wallace, J D

    2012-12-01

    Ion Chambers have a generally flat energy response with some deviations at very low (2 MeV) energies. Some improvements in the low energy response can be achieved through use of high atomic number gases, such as argon and xenon, and higher chamber pressures. This work looks at the energy response of high pressure xenon-filled ion chambers using the MCNP Monte Carlo package to develop geometric models of a commercially available high pressure ion chamber (HPIC). The use of the F6 tally as an estimator of the energy deposited in a region of interest per unit mass, and the underlying assumptions associated with its use are described. The effect of gas composition, chamber gas pressure, chamber wall thickness, and chamber holder wall thicknesses on energy response are investigated and reported. The predicted energy response curve for the HPIC was found to be similar to that reported by other investigators. These investigations indicate that improvements to flatten the overall energy response of the HPIC down to 70 keV could be achieved through use of 3 mm-thick stainless steel walls for the ion chamber.

  19. Electron excitation relaxation in wide-gap single crystal insulators under swift heavy-ion irradiation

    International Nuclear Information System (INIS)

    Yavlinskii, Yu.N.

    2000-01-01

    A heavy, multicharged ion moving in a solid interacts with nuclei and electrons of the matter atoms. If the projectile velocity exceeds the typical orbital velocity of the target electrons, the main process is excitation of the electronic subsystem, i.e., excitation and ionization of bound electrons. Initially, relaxation of the electron excitations results from electronic processes alone, and energy transfer from electrons to lattice happens later. Since free charge carriers are absent in insulators before irradiation, the motion of the excited electrons is possible only together with holes. Due to inner pressure of the electron-hole plasma the expansion takes place. The velocity of the expansion is determined by the heat velocity of electron-hole pairs. As the excitation region expands, the density of the electron-hole pairs decreases, the average distance between pairs increases, and excitons are produced. The expansion can be terminated in the time t≅10 -13 s, when, due to the electron-phonon interaction, self-trapped holes (and excitons) are formed. The annihilation of the trapped excitons gives rise to Frenkel defects. The set of equations comprising the continuity equation, the Euler equation and energy conservation is considered. The analytic dependence on time of the electron temperature and the radius of the excitation region is derived. The observation of projectile traces in a target is discussed in the single projectile regime

  20. Two-particle versus three-particle interactions in single ionization of helium by ion impact

    International Nuclear Information System (INIS)

    Schulz, M; Moshammer, R; Fischer, D; Ullrich, J

    2004-01-01

    We have performed kinematically complete experiments on single ionization of He by 100 MeV amu -1 C 6+ and 3.6 MeV amu -1 Au 24,53+ impact. By analysing doubly differential cross sections (DDCS) as a function of the momenta of all two-particle sub-systems we studied the importance of two-particle interactions. Furthermore, presenting the squared momenta of all three collision fragments simultaneously in a Dalitz plot, we evaluated the role of three-particle interactions. Finally, both for the DDCS and the Dalitz plots the corresponding correlation function was analysed. While the absolute cross sections confirm that ionization predominantly leads to a momentum exchange between the electron and the recoil-ion, the correlation function reveals strong correlations between the particles of any two-particle sub-system. Three-particle correlations, which are not accounted for by perturbative calculations, are quite significant as well, at least for certain kinematic conditions

  1. Single-color, in situ photolithography marking of individual CdTe/ZnTe quantum dots containing a single Mn{sup 2+} ion

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, K.; Malinowski, F. K.; Gałkowski, K.; Jakubczyk, T.; Kossacki, P.; Pacuski, W.; Suffczyński, J., E-mail: Jan.Suffczynski@fuw.edu.pl [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., PL-02-093 Warsaw (Poland)

    2015-01-05

    A simple, single-color method for permanent marking of the position of individual self-assembled semiconductor Quantum Dots (QDs) at cryogenic temperatures is reported. The method combines in situ photolithography with standard micro-photoluminescence spectroscopy. Its utility is proven by a systematic magnetooptical study of a single CdTe/ZnTe QD containing a Mn{sup 2+} ion, where a magnetic field of up to 10 T in two orthogonal, Faraday and Voigt, configurations is applied to the same QD. The presented approach can be applied to a wide range of solid state nanoemitters.

  2. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  3. Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions

    CERN Document Server

    Hou Ming Dong; LiuJie; Wang Zhi Guang; Jin Yun Fan; Zhu Zhi Yong; Zhen Hong Lou; Liu Chang Long; Chen Xiao Xi; Wei Xin Guo; Zhang Li; Fan You Cheng; Zhu Zhou Rong; Zhang Yiting

    2002-01-01

    Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions in different batches of 32k x 8 bits static random access memory are studied. The incident angle dependences of the cross sections for single event upset and single event latch up are presented. The SEE cross sections are plotted versus energy loss instead of linear energy transfer value in sensitive region. The depth of sensitive volume and thickness of 'dead' layer above the sensitive volume are estimated

  4. Heavy-ion interactions in relativistic mean-field models

    International Nuclear Information System (INIS)

    Rashdan, M.

    1996-01-01

    The interaction potential between spherical nuclei and the elastic scattering cross section are calculated within relativistic mean-field (linear and non-linear) models, using a generalized relativistic local density approximation. The nuclear densities are calculated self-consistently from the solution of the relativistic mean-field equations. It is found that both the linear and non-linear models predict the characteristic switching-over phenomenon of the heavy-ion nuclear potential, where the potential gets attraction with increasing energy up to some value where it reverses this behaviour. The non-linear NLC model predicts a deeper potential than the linear LW model. The elastic scattering cross section calculated within the non-linear NLC model is in better agreement with experiments than that calculated within the linear LW model. (orig.)

  5. Electrodiffusive model for astrocytic and neuronal ion concentration dynamics.

    Directory of Open Access Journals (Sweden)

    Geir Halnes

    Full Text Available The cable equation is a proper framework for modeling electrical neural signalling that takes place at a timescale at which the ionic concentrations vary little. However, in neural tissue there are also key dynamic processes that occur at longer timescales. For example, endured periods of intense neural signaling may cause the local extracellular K(+-concentration to increase by several millimolars. The clearance of this excess K(+ depends partly on diffusion in the extracellular space, partly on local uptake by astrocytes, and partly on intracellular transport (spatial buffering within astrocytes. These processes, that take place at the time scale of seconds, demand a mathematical description able to account for the spatiotemporal variations in ion concentrations as well as the subsequent effects of these variations on the membrane potential. Here, we present a general electrodiffusive formalism for modeling of ion concentration dynamics in a one-dimensional geometry, including both the intra- and extracellular domains. Based on the Nernst-Planck equations, this formalism ensures that the membrane potential and ion concentrations are in consistency, it ensures global particle/charge conservation and it accounts for diffusion and concentration dependent variations in resistivity. We apply the formalism to a model of astrocytes exchanging ions with the extracellular space. The simulations show that K(+-removal from high-concentration regions is driven by a local depolarization of the astrocyte membrane, which concertedly (i increases the local astrocytic uptake of K(+, (ii suppresses extracellular transport of K(+, (iii increases axial transport of K(+ within astrocytes, and (iv facilitates astrocytic relase of K(+ in regions where the extracellular concentration is low. Together, these mechanisms seem to provide a robust regulatory scheme for shielding the extracellular space from excess K(+.

  6. Adaptive thermal modeling of Li-ion batteries

    International Nuclear Information System (INIS)

    Shadman Rad, M.; Danilov, D.L.; Baghalha, M.; Kazemeini, M.; Notten, P.H.L.

    2013-01-01

    Highlights: • A simple, accurate and adaptive thermal model is proposed for Li-ion batteries. • Equilibrium voltages, overpotentials and entropy changes are quantified from experimental results. • Entropy changes are highly dependent on the battery State-of-Charge. • Good agreement between simulated and measured heat development is obtained under all conditions. • Radiation contributes to about 50% of heat dissipation at elevated temperatures. -- Abstract: An accurate thermal model to predict the heat generation in rechargeable batteries is an essential tool for advanced thermal management in high power applications, such as electric vehicles. For such applications, the battery materials’ details and cell design are normally not provided. In this work a simple, though accurate, thermal model for batteries has been developed, considering the temperature- and current-dependent overpotential heat generation and State-of-Charge dependent entropy contributions. High power rechargeable Li-ion (7.5 Ah) batteries have been experimentally investigated and the results are used for model verification. It is shown that the State-of-Charge dependent entropy is a significant heat source and is therefore essential to correctly predict the thermal behavior of Li-ion batteries under a wide variety of operating conditions. An adaptive model is introduced to obtain these entropy values. A temperature-dependent equation for heat transfer to the environment is also taken into account. Good agreement between the simulations and measurements is obtained in all cases. The parameters for both the heat generation and heat transfer processes can be applied to the thermal design of advanced battery packs. The proposed methodology is generic and independent on the cell chemistry and battery design. The parameters for the adaptive model can be determined by performing simple cell potential/current and temperature measurements for a limited number of charge/discharge cycles

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

    Science.gov (United States)

    Sohrabi, Mehdi

    2017-11-01

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

  8. Testing ion structure models with x-ray Thomson scattering

    Directory of Open Access Journals (Sweden)

    Wünsch K.

    2013-11-01

    Full Text Available We investigate the influence of various ionic structure models on the interpretation of the X-ray Thomson scattering signal. For the calculation of the ion structure, classical hypernetted chain equations are used applying different effective inter-particle potentials. It is shown that the different models lead to significant discrepancies in the theoretically predicted weight of the Rayleigh peak, in particular for small k-values where correlation effects are important. Here, we propose conditions which might allow for an experimental verification of the theories under consideration of experimental constraints of k-vector blurring.

  9. A quantal toy model for heavy-ion collisions

    International Nuclear Information System (INIS)

    Cassing, W.

    1987-01-01

    A one-dimensional toy model of moving finite boxes is analysed with respect to quantal phenomena associated with heavy-ion dynamics at low and intermediate energies. Special attention is payed to the relation between energy and momentum of the nucleons inside and outside the time-dependent mean field. A Wigner transformation of the one-body density matrix in space and time allows for a unique comparison with classical phase-space dynamics. It is found that high momentum components of the nuclear groundstate wave function approximately become on-shell during the heavy-ion reaction. This leads to the emission of energetic nucleons which do not appear classically. It is furthermore shown, that the low lying eigenstates of the dinuclear system for fixed time are only partly occupied throughout the reaction at intermediate energies. This opens up final phase space for nucleons after producing e.g. a pion or energetic photon. Through the present model does not allow for a reliable calculation of double differential nucleon spectra, pion or photon cross sections, it transparently shows the peculiar features of quantum dynamics in heavy-ion collisions. (orig.)

  10. Strong coupling between a single nitrogen-vacancy spin and the rotational mode of diamonds levitating in an ion trap

    Science.gov (United States)

    Delord, T.; Nicolas, L.; Chassagneux, Y.; Hétet, G.

    2017-12-01

    A scheme for strong coupling between a single atomic spin and the rotational mode of levitating nanoparticles is proposed. The idea is based on spin readout of nitrogen-vacancy centers embedded in aspherical nanodiamonds levitating in an ion trap. We show that the asymmetry of the diamond induces a rotational confinement in the ion trap. Using a weak homogeneous magnetic field and a strong microwave driving we then demonstrate that the spin of the nitrogen-vacancy center can be strongly coupled to the rotational mode of the diamond.

  11. Effects of tube diameter and chirality on the stability of single-walled carbon nanotubes under ion irradiation

    International Nuclear Information System (INIS)

    Xu Zijian; Zhang Wei; Zhu Zhiyuan; Ren Cuilan; Li Yong; Huai Ping

    2009-01-01

    Using molecular dynamics method, we investigated the influence of tube diameter and chirality on the stability of single-walled carbon nanotubes (CNTs) under ion irradiation. We found that in the energy range below 1 keV, the dependence of CNT stability on the tube diameter is no longer monotonic under C ion irradiation, and the thinner (5, 5) CNT may be more stable than the thicker (7, 7) CNT, while under Ar irradiation, the CNT stability increases still monotonically with the CNT diameter. This stability behavior was further verified by the calculations of the threshold ion energies to produce displacement damage in CNTs. The abnormal stability of thin CNTs is related to their resistance to the instantaneous deformation in the wall induced by ion pushing, the high self-healing capacity, as well as the different interaction properties of C and Ar ions with CNT atoms. We also found that under ion irradiation the stability of a zigzag CNT is better than that of an armchair CNT with the same diameter. This is because of the bonding structure difference between the armchair and the zigzag CNTs with respect to the orientations of graphitic networks as well as the self-healing capacity difference.

  12. Radiation Environment Model of Protons and Heavier Ions at Jupiter

    Science.gov (United States)

    Sierra, Luz Maria Martinez; Garrett, Henry B.; Jun, Insoo

    2015-01-01

    We performed an in depth study of the methods used to review the geometric factors (GF) and sensitivity to charge particles of the Energetic Particle Detector instrument on board the Galileo Spacecraft. Monte Carlo simulations were performed to understand the interactions of electrons and ions (i. e., protons and alphas) with the sensitive regions of the instrument. The DC0 and B0 channels were studied with the intention of using them to update the jovian proton radiation model. The results proved that the B0 is a clean proton chanel without any concerns for contamination by heavier ions and electrons. In contrast, DC0 was found to be contaminated by electrons. Furthermore, we also found out that the B2 channel is a clean alpha particle channel (in other words, no contamination by electrons and/or protons).

  13. Thermal Environmental Testing of NSTAR Engineering Model Ion Thrusters

    Science.gov (United States)

    Rawlin, Vincent K.; Patterson, Michael J.; Becker, Raymond A.

    1999-01-01

    NASA's New Millenium program will fly a xenon ion propulsion system on the Deep Space 1 Mission. Tests were conducted under NASA's Solar Electric Propulsion Technology Applications Readiness (NSTAR) Program with 3 different engineering model ion thrusters to determine thruster thermal characteristics over the NSTAR operating range in a variety of thermal environments. A liquid nitrogen-cooled shroud was used to cold-soak the thruster to -120 C. Initial tests were performed prior to a mature spacecraft design. Those results and the final, severe, requirements mandated by the spacecraft led to several changes to the basic thermal design. These changes were incorporated into a final design and tested over a wide range of environmental conditions.

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

    Science.gov (United States)

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

    2017-10-01

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

  15. Factors affecting GEBV accuracy with single-step Bayesian models.

    Science.gov (United States)

    Zhou, Lei; Mrode, Raphael; Zhang, Shengli; Zhang, Qin; Li, Bugao; Liu, Jian-Feng

    2018-01-01

    A single-step approach to obtain genomic prediction was first proposed in 2009. Many studies have investigated the components of GEBV accuracy in genomic selection. However, it is still unclear how the population structure and the relationships between training and validation populations influence GEBV accuracy in terms of single-step analysis. Here, we explored the components of GEBV accuracy in single-step Bayesian analysis with a simulation study. Three scenarios with various numbers of QTL (5, 50, and 500) were simulated. Three models were implemented to analyze the simulated data: single-step genomic best linear unbiased prediction (GBLUP; SSGBLUP), single-step BayesA (SS-BayesA), and single-step BayesB (SS-BayesB). According to our results, GEBV accuracy was influenced by the relationships between the training and validation populations more significantly for ungenotyped animals than for genotyped animals. SS-BayesA/BayesB showed an obvious advantage over SSGBLUP with the scenarios of 5 and 50 QTL. SS-BayesB model obtained the lowest accuracy with the 500 QTL in the simulation. SS-BayesA model was the most efficient and robust considering all QTL scenarios. Generally, both the relationships between training and validation populations and LD between markers and QTL contributed to GEBV accuracy in the single-step analysis, and the advantages of single-step Bayesian models were more apparent when the trait is controlled by fewer QTL.

  16. A single grain approach applied to modelling recrystallization kinetics in a single-phase metal

    NARCIS (Netherlands)

    Chen, S.P.; Zwaag, van der S.

    2004-01-01

    A comprehensive model for the recrystallization kinetics is proposed which incorporates both microstructure and the textural components in the deformed state. The model is based on the single-grain approach proposed previously. The influence of the as-deformed grain orientation, which affects the

  17. Single potential electrodeposition of nanostructured battery materials for lithium-ion batteries

    Science.gov (United States)

    Mosby, James Matthew

    The increasing reliance on portable electronics is continuing to fuel research in the area of low power lithium-ion batteries, while a new surge in research for high power lithium-ion batteries has been sparked by the demand for plug-in hybrid electric vehicles (PHEV) and plug-in electric vehicles (PEV). To compete with current lead-acid battery chemistry, a few of the shortcomings of lithium-ion battery chemistry need to be addressed. The three main drawbacks of lithium-ion batteries for this application are: (1) low power density, (2) safety, and (3) the high cost of manufacturing. This dissertation covers the development of a low cost fabrication technique for an alternative anode material with high surface area geometries. The anode material is safer than the conventional anode material in lithium-ion batteries and the high surface area geometries permit higher power densities to be achieved. Electrodeposition is an inexpensive alternative method for synthesizing materials for electronics, energy conversion and energy storage applications relative to traditional solid state techniques. These techniques led to expensive device fabrication. Unlike most solid state synthesis routes, electrodeposition can usually be performed from common solutions and at moderate conditions. Three other benefits of using electrodeposition are: (1) it allows precise control of composition and crystallinity, (2) it provides the ability to deposit on complex shapes, and (3) it can deposit materials with nanoscale dimensions. The use of electrodeposition for alternative anode materials results in the deposition of the material directly onto the current collector that is used for the battery testing and applications without the need of additional binders and with excellent electrical contact. While this improves the characterization of the material and lowers the weight of the non-active materials within a battery, it also allows the anode to be deposited onto current collectors with

  18. Modeling injected interstitial effects on void swelling in self-ion irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Short, M.P., E-mail: hereiam@mit.edu [Dept. of Nuclear Science and Engineering, Massachusetts Institute of Technology (United States); Gaston, D.R. [Idaho National Laboratory (United States); Jin, M. [Dept. of Nuclear Science and Engineering, Massachusetts Institute of Technology (United States); Shao, L. [Dept. of Nuclear Engineering, Texas A& M University (United States); Garner, F.A. [Radiation Effects Consulting, LLC (United States)

    2016-04-01

    Heavy ion irradiations at high dose rates are often used to simulate slow and expensive neutron irradiation experiments. However, many differences in the resultant modes of damage arise due to unique aspects of heavy ion irradiation. One such difference was recently shown in pure iron to manifest itself as a double peak in void swelling, with both peaks located away from the region of highest displacement damage. In other cases involving a variety of ferritic alloys there is often only a single peak in swelling vs. depth that is located very near the ion-incident surface. We show that these behaviors arise due to a combination of two separate effects: 1) suppression of void swelling due to injected interstitials, and 2) preferential sinking of interstitials to the ion-incident surface, which are very sensitive to the irradiation temperature and displacement rate. Care should therefore be used in collection and interpretation of data from the depth range outside the Bragg peak of ion irradiation experiments, as it is shown to be more complex than previously envisioned. - Highlights: • A model of the spatially dependent point defect kinetics equations with injected interstitials has been implemented. • The results predict a double peak in the void nucleation rate, helping to explain a recent experiment. • The double peak is predicted to be evident within a narrow (+/− 30 °C) temperature window for self-irradiation of pure iron. • The ballistic damage profile may not match the resultant void swelling profile from ion irradiation experiments.

  19. Tests of the single-pion exchange model

    International Nuclear Information System (INIS)

    Treiman, S.B.; Yang, C.N.

    1983-01-01

    The single-pion exchange model (SPEM) of high-energy particle reactions provides an attractively simple picture of seemingly complex processes and has accordingly been much discussed in recent times. The purpose of this note is to call attention to the possibility of subjecting the model to certain tests precisely in the domain where the model stands the best chance of making sense

  20. Modeling of calcination of single kaolinitic clay particle

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    The present work aims at modeling of the calcination (dehydroxylation) process of clay particles, specifically kaolinite, and its thermal transformation. For such purpose, 1D single particle calcination model was developed based on the concept of shrinking core model to assess the dehydroxylation...

  1. Measuring kinetics of complex single ion channel data using mean-variance histograms.

    Science.gov (United States)

    Patlak, J B

    1993-07-01

    The measurement of single ion channel kinetics is difficult when those channels exhibit subconductance events. When the kinetics are fast, and when the current magnitudes are small, as is the case for Na+, Ca2+, and some K+ channels, these difficulties can lead to serious errors in the estimation of channel kinetics. I present here a method, based on the construction and analysis of mean-variance histograms, that can overcome these problems. A mean-variance histogram is constructed by calculating the mean current and the current variance within a brief "window" (a set of N consecutive data samples) superimposed on the digitized raw channel data. Systematic movement of this window over the data produces large numbers of mean-variance pairs which can be assembled into a two-dimensional histogram. Defined current levels (open, closed, or sublevel) appear in such plots as low variance regions. The total number of events in such low variance regions is estimated by curve fitting and plotted as a function of window width. This function decreases with the same time constants as the original dwell time probability distribution for each of the regions. The method can therefore be used: 1) to present a qualitative summary of the single channel data from which the signal-to-noise ratio, open channel noise, steadiness of the baseline, and number of conductance levels can be quickly determined; 2) to quantify the dwell time distribution in each of the levels exhibited. In this paper I present the analysis of a Na+ channel recording that had a number of complexities. The signal-to-noise ratio was only about 8 for the main open state, open channel noise, and fast flickers to other states were present, as were a substantial number of subconductance states. "Standard" half-amplitude threshold analysis of these data produce open and closed time histograms that were well fitted by the sum of two exponentials, but with apparently erroneous time constants, whereas the mean

  2. Mixture of Regression Models with Single-Index

    OpenAIRE

    Xiang, Sijia; Yao, Weixin

    2016-01-01

    In this article, we propose a class of semiparametric mixture regression models with single-index. We argue that many recently proposed semiparametric/nonparametric mixture regression models can be considered special cases of the proposed model. However, unlike existing semiparametric mixture regression models, the new pro- posed model can easily incorporate multivariate predictors into the nonparametric components. Backfitting estimates and the corresponding algorithms have been proposed for...

  3. Modeling of charge transport in ion bipolar junction transistors.

    Science.gov (United States)

    Volkov, Anton V; Tybrandt, Klas; Berggren, Magnus; Zozoulenko, Igor V

    2014-06-17

    Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters.

  4. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions.

    Science.gov (United States)

    Yigit, Cemil; Heyda, Jan; Dzubiella, Joachim

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  5. Modelling heavy-ion energy deposition in extended media

    International Nuclear Information System (INIS)

    Mishustin, I.; Pshenichnov, I.; Greiner, W.; Mishustin, I.; Pshenichnov, I.

    2010-01-01

    We present recent developments of the Monte Carlo model for heavy-ion therapy (MCHIT), which is currently based on the Geant4 tool-kit of version 9.2. The major advancement of the model concerns the modelling of violent fragmentation reactions by means of the Fermi break-up model, which is used to simulate decays of hot fragments created after the first stage of nucleus-nucleus collisions. By means of MCHIT we study the dose distributions from therapeutic beams of carbon nuclei in tissue-like materials, like water and PMMA. The contributions to the total dose from primary beam nuclei and from charged secondary fragments produced in nuclear fragmentation reactions are calculated. The build-up of secondary fragments along the beam axis is calculated and compared with available experimental data. Finally, we demonstrate the impact of violent multifragment decays on energy distributions of secondary neutrons produced by carbon nuclei in water. (authors)

  6. Modelling heavy-ion energy deposition in extended media

    Energy Technology Data Exchange (ETDEWEB)

    Mishustin, I.; Pshenichnov, I.; Greiner, W. [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, Frankfurt am Main (Germany); Mishustin, I. [Kurchatov Institute, Russian Research Center, Moscow (Russian Federation); Pshenichnov, I. [Institute for Nuclear Research, Russian Academy of Science, Moscow (Russian Federation)

    2010-10-15

    We present recent developments of the Monte Carlo model for heavy-ion therapy (MCHIT), which is currently based on the Geant4 tool-kit of version 9.2. The major advancement of the model concerns the modelling of violent fragmentation reactions by means of the Fermi break-up model, which is used to simulate decays of hot fragments created after the first stage of nucleus-nucleus collisions. By means of MCHIT we study the dose distributions from therapeutic beams of carbon nuclei in tissue-like materials, like water and PMMA. The contributions to the total dose from primary beam nuclei and from charged secondary fragments produced in nuclear fragmentation reactions are calculated. The build-up of secondary fragments along the beam axis is calculated and compared with available experimental data. Finally, we demonstrate the impact of violent multifragment decays on energy distributions of secondary neutrons produced by carbon nuclei in water. (authors)

  7. A Simple Model of Wings in Heavy-Ion Collisions

    CERN Document Server

    Parikh, Aditya

    2015-01-01

    We create a simple model of heavy ion collisions independent of any generators as a way of investigating a possible source of the wings seen in data. As a first test, we reproduce a standard correlations plot to verify the integrity of the model. We then proceed to test whether an η dependent v2 could be a source of the wings and take projections along multiple Δφ intervals and compare with data. Other variations of the model are tested by having dN/dφ and v2 depend on η as well as including pions and protons into the model to make it more realistic. Comparisons with data seem to indicate that an η dependent v2 is not the main source of the wings.

  8. Exactly solved mixed spin-(1,1/2) Ising–Heisenberg diamond chain with a single-ion anisotropy

    International Nuclear Information System (INIS)

    Lisnyi, Bohdan; Strečka, Jozef

    2015-01-01

    The mixed spin-(1,1/2) Ising–Heisenberg diamond chain with a single-ion anisotropy is exactly solved through the generalized decoration–iteration transformation and the transfer-matrix method. The decoration–iteration transformation is first used for establishing a rigorous mapping equivalence with the corresponding spin-1 Blume–Emery–Griffiths chain, which is subsequently exactly treated within the transfer-matrix technique. Apart from three classical ground states the model exhibits three striking quantum ground states in which a singlet-dimer state of the interstitial Heisenberg spins is accompanied either with a frustrated state or a polarized state or a non-magnetic state of the nodal Ising spins. It is evidenced that two magnetization plateaus at zero and/or one-half of the saturation magnetization may appear in low-temperature magnetization curves. The specific heat may display remarkable temperature dependences with up to three and four distinct round maxima in a zero and non-zero magnetic field, respectively. - Highlights: • Mixed spin-(1,1/2) Ising–Heisenberg diamond chain is exactly solved. • Quantum ground states with a singlet-dimer state of the Heisenberg spins are found. • Magnetization curve displays intermediate plateaus at zero and half of full magnetization. • Thermal dependences of specific heat may display up to four distinct peaks

  9. Early Stage of Deformation under Nanoindenter Tip of Ion-irradiated Single Crystals

    International Nuclear Information System (INIS)

    Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun

    2010-01-01

    Ion irradiation has been used for almost 40 years to emulate the effect of neutrons. Ion irradiation has a number of advantages in terms of time and expenses compared to neutron irradiation. Ion irradiation is expected to greatly contribute to the development of Fusion and Gen IV materials. Ions have short penetration depth, and they induce continuously varying dose rate over the penetration depth. Although it depends on the energy and species of incident ions, the depth of ion-irradiated region is in general on the order of a few micron meters. Depth controlled probing technique is required to measure the mechanical properties of ion-irradiated layer, and nanoindentation is widely used. During nanoindentation, a hard tip with known properties is pressed into a material which has unknown properties. The depth of penetration and load on the indenter are recorded during loading and unloading. The initial Loading depth curve follows the Hertzian elastic solution, and at a certain load, a sudden displacement excursion occurs in indenter depth and then hardening follows. This is called 'Pop-in' event, and since residual impression can be found only after pop-ins, the pop-in is regarded as the onset of plasticity. The objectives of this research are to investigate the effects of ion irradiation on popins, and to examine dislocation nucleation and propagation at the onset of plasticity by using MD simulations

  10. Early Stage of Deformation under Nanoindenter Tip of Ion-irradiated Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    Ion irradiation has been used for almost 40 years to emulate the effect of neutrons. Ion irradiation has a number of advantages in terms of time and expenses compared to neutron irradiation. Ion irradiation is expected to greatly contribute to the development of Fusion and Gen IV materials. Ions have short penetration depth, and they induce continuously varying dose rate over the penetration depth. Although it depends on the energy and species of incident ions, the depth of ion-irradiated region is in general on the order of a few micron meters. Depth controlled probing technique is required to measure the mechanical properties of ion-irradiated layer, and nanoindentation is widely used. During nanoindentation, a hard tip with known properties is pressed into a material which has unknown properties. The depth of penetration and load on the indenter are recorded during loading and unloading. The initial Loading depth curve follows the Hertzian elastic solution, and at a certain load, a sudden displacement excursion occurs in indenter depth and then hardening follows. This is called 'Pop-in' event, and since residual impression can be found only after pop-ins, the pop-in is regarded as the onset of plasticity. The objectives of this research are to investigate the effects of ion irradiation on popins, and to examine dislocation nucleation and propagation at the onset of plasticity by using MD simulations

  11. Cationized phenylalanine conformations characterized by IRMPD and computation for singly and doubly charged ions

    NARCIS (Netherlands)

    Dunbar, R.C.; Steill, J.D.; Oomens, J.

    2010-01-01

    Electrospray ionization produces phenylalanine (Phe) complexes of the alkali metal ion series, plus Ag+ and Ba2+. Infrared multiple photon dissociation (IRMPD) spectroscopy using the FELIX free electron laser light source is used to characterize the conformations of the ions, in conjunction with

  12. Potent neutralization of influenza A virus by a single-domain antibody blocking M2 ion channel protein.

    Directory of Open Access Journals (Sweden)

    Guowei Wei

    Full Text Available Influenza A virus poses serious health threat to humans. Neutralizing antibodies against the highly conserved M2 ion channel is thought to offer broad protection against influenza A viruses. Here, we screened synthetic Camel single-domain antibody (VHH libraries against native M2 ion channel protein. One of the isolated VHHs, M2-7A, specifically bound to M2-expressed cell membrane as well as influenza A virion, inhibited replication of both amantadine-sensitive and resistant influenza A viruses in vitro, and protected mice from a lethal influenza virus challenge. Moreover, M2-7A showed blocking activity for proton influx through M2 ion channel. These pieces of evidence collectively demonstrate for the first time that a neutralizing antibody against M2 with broad specificity is achievable, and M2-7A may have potential for cross protection against a number of variants and subtypes of influenza A viruses.

  13. Ion beam modification of thermal stress resistance of MgO single crystals with different crystallographic faces

    International Nuclear Information System (INIS)

    Gurarie, V.N.; Otsuka, P.H.; Williams, J.S.; Conway, M.J.

    2000-01-01

    Ion beam modification of thermal shock stress resistance of MgO single crystals with various crystallographic faces is investigated. The most stable crystal faces in terms of stress and damage resistance are established. Ion implantation is shown to reduce the temperature threshold of fracture for all crystal faces tested. The (111) face is demonstrated to be of highest stability compared to (110) and (100) faces in both implanted and unimplanted crystals. At the same time ion implantation substantially increases the microcrack density for all the faces tested and reduces the degree of fracture damage following thermal shock. The theoretical resistance parameters for various crystal faces are calculated using the continuum mechanics approach. The results are discussed on the basis of fracture mechanics principles and the effect of the implantation-induced lattice damage on crack nucleation

  14. Ion beam modification of thermal stress resistance of MgO single crystals with different crystallographic faces

    International Nuclear Information System (INIS)

    Gurarie, V.N.; Otsuka, P.H.; Jamieson, D.N.; Williams, J.S.; Conway, M.

    1999-01-01

    Ion beam modification of thermal shock stress and damage resistance of MgO single crystals with various crystallographic faces is investigated. The most stable crystal faces in terms of stress and damage resistance are established. Ion implantation is shown to reduce the temperature threshold of fracture for all crystal faces tested. The (111) face is demonstrated to be of highest stability compared to (110) and (100) faces in both implanted and unimplanted crystals. At the same time ion implantation substantially increases the microcrack density for the faces tested and reduces the degree of fracture damage following thermal shock. The microcrack density is found to be highest in the crystals with (110) face in comparison with the (001) and (111) faces. The effect is analysed using fracture mechanics principles and discussed in terms of the implantation-induced lattice damage

  15. Carrier transfer and magneto-transport in single modulation-doped V-grooved quantum wire modified by ion implantation

    International Nuclear Information System (INIS)

    Huang, S.H.; Chen Zhanghai; Wang, F.Z.; Shen, S.C.; Tan, H.H.; Fu, L.; Fraser, M.; Jagadish, C.

    2006-01-01

    A single Al 0.5 Ga 0.5 As/GaAs V-grooved quantum wire modified by selective ion implantation and rapid thermal annealing was investigated by using spatially resolved micro-photoluminescence spectroscopy and magneto-resistance measurements. The results of spatially resolved photoluminescence indicate that the ion-implantation-induced quantum well intermixing significantly raises the electronic sub-band energies in the side quantum wells (SQWs) and vertical quantum wells, and a more efficient accumulation of electrons in the quantum wires is achieved. Processes of real space carrier transfer from the SQW to the quantum wire was experimentally observed, and showed the blocking effect of carrier transfer due to the existence of the necking quantum well region. Furthermore, magneto-transport investigation on the ion-implanted quantum wire samples shows the quasi-one-dimensional intrinsic motion of electrons, which is important for the design and the optimization of one-dimensional electronic devices

  16. Development of a dual ion beam system with single accelerator for materials studies

    International Nuclear Information System (INIS)

    Suzuki, Kazumichi; Nishimura, Eiichi; Hashimoto, Tsuneyuki

    1986-01-01

    The dual ion beam accelerator system has been developed for simulation studies of neutron radiation damage of structural materials for nuclear fusion and fission reactors. One accelerator is used to accelerate two different kinds of ions, which are generated in the ion source simultaneously. One of these ions is selected alternatively by switching the magnetic field of the analyzing magnet, and is then accelerated to the desired energy value. The system is controlled by a microcomputer. The accelerator used in the system is a conventional 400 kV Cockcroft-Walton accelerator. The performance test by the acceleration of He + and Ar + shows that the system is capable of accelerating two ions alternatively with a switching time of less than 22 s. The beam current obtained with the microcomputer control is more than 98% of the current obtained by manual operation. (orig.)

  17. Experiments and modeling of single plastic particle conversion in suspension

    DEFF Research Database (Denmark)

    Nakhaei, Mohammadhadi; Wu, Hao; Grévain, Damien

    2018-01-01

    Conversion of single high density polyethylene (PE) particles has been studied by experiments and modeling. The experiments were carried out in a single particle combustor for five different shapes and masses of particles at temperature conditions of 900 and 1100°C. Each experiment was recorded...... against the experiments as well as literature data. Furthermore, a simplified isothermal model appropriate for CFD applications was developed, in order to model the combustion of plastic particles in cement calciners. By comparing predictions with the isothermal and the non–isothermal models under typical...

  18. Introduction to fluid model for RHIC heavy ion collisions

    International Nuclear Information System (INIS)

    Muraya, Shin

    2007-01-01

    An introductory review of the fluid model which has been looked upon as the promising phenomenological model for the heavy ion scattering experiments at RHIC is presented here. Subjects are especially focused on the fundamental assumptions of the model and the decision process of the phenomenological parameters considering newcomers to hadron physics. Introduction of thermodynamical quantities, 1+1 dimension model, time-space evolution of fluid, correspondence of fluid to particles, initial condition, boundary condition and comparison of the equation of state of fluid model and that of hadron model are described. Limitation of fluid picture and the validity of the model are discussed finally. It is summarized that the present fluid model does not predict much about results in advance but gives interpretation after the event, nevertheless it reproduces much of the experimental results in natural form. It is expected that the parameter of the fluid model is to be used as the intermediate theory to relate experimental results with theory. (S. Funahashi)

  19. The Formation of High-Coercivity, Oriented, Nanophase Cobalt Precipitates in Al2O3 single cyrstals by ion implantation

    International Nuclear Information System (INIS)

    Honda, S.; Modine, F.A.; Haynes, T.E.; Meldrum, A.; Budai, J.D.; SOng, K.J.; Thompson, J.R.; Boatner, L.A.

    1999-01-01

    Ion-implantation and thermal-processing methods have been used to form nanophase magnetic precipitates of metallic cobalt that are embedded in the near-surface region of single crystals of Al 2 O 3 . The Co precipitates are isolated, single-crystal particles that are crystallographically oriented with respect to the host Al 2 O 3 lattice. Embedded nanophase Co precipitates were formed by the implantation of Co+ at an energy of 140 keV and a dose of 8 x l0 16 ions/cm 2 followed by annealing in a reducing atmosphere. The implanted/annealed Co depth profile, particle size distributions and shapes, and the orientational relationship between the nanophase precipitates and the host crystal lattice were determined using RBS/channeling, transmission electron microscopy, and x-ray diffraction

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

    Science.gov (United States)

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

    2017-12-01

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

  1. Junctionless Diode Enabled by Self-Bias Effect of Ion Gel in Single-Layer MoS2 Device.

    Science.gov (United States)

    Khan, Muhammad Atif; Rathi, Servin; Park, Jinwoo; Lim, Dongsuk; Lee, Yoontae; Yun, Sun Jin; Youn, Doo-Hyeb; Kim, Gil-Ho

    2017-08-16

    The self-biasing effects of ion gel from source and drain electrodes on electrical characteristics of single layer and few layer molybdenum disulfide (MoS 2 ) field-effect transistor (FET) have been studied. The self-biasing effect of ion gel is tested for two different configurations, covered and open, where ion gel is in contact with either one or both, source and drain electrodes, respectively. In open configuration, the linear output characteristics of the pristine device becomes nonlinear and on-off ratio drops by 3 orders of magnitude due to the increase in "off" current for both single and few layer MoS 2 FETs. However, the covered configuration results in a highly asymmetric output characteristics with a rectification of around 10 3 and an ideality factor of 1.9. This diode like behavior has been attributed to the reduction of Schottky barrier width by the electric field of self-biased ion gel, which enables an efficient injection of electrons by tunneling at metal-MoS 2 interface. Finally, finite element method based simulations are carried out and the simulated results matches well in principle with the experimental analysis. These self-biased diodes can perform a crucial role in the development of high-frequency optoelectronic and valleytronic devices.

  2. Phase transitions and multicritical points in the mixed spin-32 and spin-2 Ising system with a single-ion anisotropy

    International Nuclear Information System (INIS)

    Bobak, A.; Dely, J.

    2007-01-01

    The effect of a single-ion anisotropy on the phase diagram of the mixed spin-32 and spin-2 Ising system is investigated by the use of a mean-field theory based on the Bogoliubov inequality for the free energy. Topologically different kinds of phase diagrams are achieved by changing values of the parameter in the model Hamiltonian. Besides second-order transitions, lines of first-order transitions terminating either at a tricritical point or an isolated critical point, are found

  3. A simple model for low energy ion-solid interactions

    International Nuclear Information System (INIS)

    Mohajerzadeh, S.; Selvakumar, C.R.

    1997-01-01

    A simple analytical model for ion-solid interactions, suitable for low energy beam depositions, is reported. An approximation for the nuclear stopping power is used to obtain the analytic solution for the deposited energy in the solid. The ratio of the deposited energy in the bulk to the energy deposited in the surface yields a ceiling for the beam energy above which more defects are generated in the bulk resulting in defective films. The numerical evaluations agree with the existing results in the literature. copyright 1997 American Institute of Physics

  4. Variance Function Partially Linear Single-Index Models1.

    Science.gov (United States)

    Lian, Heng; Liang, Hua; Carroll, Raymond J

    2015-01-01

    We consider heteroscedastic regression models where the mean function is a partially linear single index model and the variance function depends upon a generalized partially linear single index model. We do not insist that the variance function depend only upon the mean function, as happens in the classical generalized partially linear single index model. We develop efficient and practical estimation methods for the variance function and for the mean function. Asymptotic theory for the parametric and nonparametric parts of the model is developed. Simulations illustrate the results. An empirical example involving ozone levels is used to further illustrate the results, and is shown to be a case where the variance function does not depend upon the mean function.

  5. Investigations on heavy ion induced Single-Event Transients (SETs) in highly-scaled FinFETs

    Energy Technology Data Exchange (ETDEWEB)

    Gaillardin, M., E-mail: marc.gaillardin@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Raine, M.; Paillet, P. [CEA, DAM, DIF, F-91297 Arpajon (France); Adell, P.C. [Jet Propulsion Laboratory, Pasadena, CA 91101 (United States); Girard, S. [Université de Saint-Etienne, Laboratoire H. Curien, UMR-5516, 42000 Saint-Etienne (France); Duhamel, O. [CEA, DAM, DIF, F-91297 Arpajon (France); Andrieu, F.; Barraud, S.; Faynot, O. [CEA, LETI-Minatec, 17 avenue des Martyrs, 38000 Grenoble (France)

    2015-12-15

    We investigate Single-Event Transients (SET) in different designs of multiple-gate devices made of FinFETs with various geometries. Heavy ion experimental results are explained by using a thorough charge collection analysis of fast transients measured on dedicated test structures. Multi-level simulations are performed to get new insights into the charge collection mechanisms in multiple-gate devices. Implications for multiple-gate device design hardening are finally discussed.

  6. Liquid-drop model applied to heavy ions irradiation

    International Nuclear Information System (INIS)

    De Cicco, Hernan; Alurralde, Martin A.; Saint-Martin, Maria L. G.; Bernaola, Omar A.

    1999-01-01

    Liquid-drop model is used, previously applied in the study of radiation damage in metals, in an energy range not covered by molecular dynamics, in order to understand experimental data of particle tracks in an organic material (Makrofol E), which cannot be accurately described by the existing theoretical methods. The nuclear and electronic energy depositions are considered for each ion considered and the evolution of the thermal explosion is evaluated. The experimental observation of particle tracks in a region previously considered as 'prohibited' are justified. Although the model used has free parameters and some discrepancies with the experimental diametrical values exist, the agreement obtained is highly superior than that of other existing models. (author)

  7. The fusion of heavy ions in an interaction potential model

    International Nuclear Information System (INIS)

    Zipper, W.

    1980-01-01

    The paper contains the problems connected with fusion processes in heavy ions collision. Results of experimental fusion data for reactions: 9 Be + 12 C, 6 Li + 28 Si, 9 Be + 28 Si, 12 C + 28 Si, 12 C + 16 O and 16 O + 16 O are presented. Comparison of measured fusion cross sections with predictions of the fusion potential model have been made. The validity of this model for both light systems, like 9 Be + 12 C and heavy systems, like 35 Cl + 62 Ni, have been discussed. In conclusion, it should be stated that fusion cross sections could be correctly predicted by the potential model with a potential describing the elastic scattering data. (author)

  8. RF Plasma modeling of the Linac4 H− ion source

    CERN Document Server

    Mattei, S; Hatayama, A; Lettry, J; Kawamura, Y; Yasumoto, M; Schmitzer, C

    2013-01-01

    This study focuses on the modelling of the ICP RF-plasma in the Linac4 H− ion source currently being constructed at CERN. A self-consistent model of the plasma dynamics with the RF electromagnetic field has been developed by a PIC-MCC method. In this paper, the model is applied to the analysis of a low density plasma discharge initiation, with particular interest on the effect of the external magnetic field on the plasma properties, such as wall loss, electron density and electron energy. The use of a multi-cusp magnetic field effectively limits the wall losses, particularly in the radial direction. Preliminary results however indicate that a reduced heating efficiency results in such a configuration. The effect is possibly due to trapping of electrons in the multi-cusp magnetic field, preventing their continuous acceleration in the azimuthal direction.

  9. Kinetic modelling for zinc (II) ions biosorption onto Luffa cylindrica

    International Nuclear Information System (INIS)

    Oboh, I.; Aluyor, E.; Audu, T.

    2015-01-01

    The biosorption of Zinc (II) ions onto a biomaterial - Luffa cylindrica has been studied. This biomaterial was characterized by elemental analysis, surface area, pore size distribution, scanning electron microscopy, and the biomaterial before and after sorption, was characterized by Fourier Transform Infra Red (FTIR) spectrometer. The kinetic nonlinear models fitted were Pseudo-first order, Pseudo-second order and Intra-particle diffusion. A comparison of non-linear regression method in selecting the kinetic model was made. Four error functions, namely coefficient of determination (R 2 ), hybrid fractional error function (HYBRID), average relative error (ARE), and sum of the errors squared (ERRSQ), were used to predict the parameters of the kinetic models. The strength of this study is that a biomaterial with wide distribution particularly in the tropical world and which occurs as waste material could be put into effective utilization as a biosorbent to address a crucial environmental problem

  10. Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

    Science.gov (United States)

    Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

    2016-07-01

    The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

  11. Tumor induction in mice after local irradiation with single doses of either carbon-ion beams or gamma rays.

    Science.gov (United States)

    Ando, Koichi; Koike, Sachiko; Ohmachi, Yasushi; Ando, Yutaka; Kobashi, Gen

    2014-12-01

    To determine the dose-dependent relative biological effectiveness (RBE) for tumor prevalence in mice receiving single localized doses to their right leg of either carbon ions (15, 45 or 75 keV/μm) or 137Cs gamma rays. A total of 1647 female C3H mice were irradiated to their hind legs with a localized dose of either reference gamma rays or 15, 45 or 75 keV/μm carbon-ion beams. Irradiated mice were evaluated for tumors twice a month during their three-year life span, and the dimensions of any tumors found were measured with a caliper. The tumor induction frequency was calculated by Kaplan-Meier analysis. The incidence of tumors from 50 Gy of 45 keV/μm carbon ions was marginally higher than those from 50 Gy of gamma rays. However, 60 Gy of 15 keV/μm carbon ions induced significantly fewer tumors than did gamma rays. RBE values of 0.87 + 0.12, 1.29 + 0.08 or 2.06 + 0.39 for lifetime tumorigenesis were calculated for 15, 45 or 75 keV/μm carbon-ion beams, respectively. Fibrosarcoma predominated, with no Linear Energy Transfer (LET)-dependent differences in the tumor histology. Experiments measuring the late effect of leg skin shrinkage suggested that the carcinogenic damage of 15 keV/μm carbon ions would be less than that of gamma rays. We conclude that patients receiving radiation doses to their normal tissues would face less risk of secondary tumor induction by carbon ions of intermediate LET values compared to equivalent doses of photons.

  12. A detailed physical model for ion implant induced damage in silicon

    International Nuclear Information System (INIS)

    Tian, S.; Morris, M.F.; Morris, S.J.; Obradovic, B.; Wang, G.; Tasch, A.F.

    1998-01-01

    A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF 2 , and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model has been incorporated in the UT-MARLOWE ion implantation simulator, and has been developed primarily for use in engineering workstations. This damage model is the most physical model in the literature to date within the framework of the binary collision approximation (BCA), and provides the required, accurate as-implanted impurity profiles and damage profiles for transient enhanced diffusion (TED) simulation

  13. Comparison of collisionless macroscopic models and application to the ion-electron instability

    International Nuclear Information System (INIS)

    Ahedo, E.; Lapuerta, V.

    2001-01-01

    In a first part, different macroscopic models of linear Landau damping are compared using a concise one-dimensional (1-D) collisionless formulation. The three-moment model of Chang and Callen (CC) [Phys. Fluids B 4, 1167 (1992)] with two closure relations (complex in the Fourier space) for the viscous stress and the heat conduction is found to be equivalent to the two-moment model of Stubbe-Sukhorukov (SS) [Phys. Plasmas 6, 2976 (1999)], which uses a single (complex) closure relation for the pressure. The comparison of the respective closure relations favors clearly the SS pressure law, which associates an anomalous resistivity to the Landau damping. In a second part, a macroscopic interpretation, with the SS model, of the ion-electron instability shows its resistive character for low and intermediate drift velocities, and the transition to the reactive Buneman limit. The pressure law for the electrons is found to verify a simple law, whereas approximate laws are discussed for the ion pressure. These laws are used to close a macroscopic model for stability analyses of nonhomogeneous plasma structures, where SS and CC models are not applicable easily

  14. Manipulating Ion Migration for Highly Stable Light-Emitting Diodes with Single-Crystalline Organometal Halide Perovskite Microplatelets.

    Science.gov (United States)

    Chen, Mingming; Shan, Xin; Geske, Thomas; Li, Junqiang; Yu, Zhibin

    2017-06-27

    Ion migration has been commonly observed as a detrimental phenomenon in organometal halide perovskite semiconductors, causing the measurement hysteresis in solar cells and ultrashort operation lifetimes in light-emitting diodes. In this work, ion migration is utilized for the formation of a p-i-n junction at ambient temperature in single-crystalline organometal halide perovskites. The junction is subsequently stabilized by quenching the ionic movement at a low temperature. Such a strategy of manipulating the ion migration has led to efficient single-crystalline light-emitting diodes that emit 2.3 eV photons starting at 1.8 V and sustain a continuous operation for 54 h at ∼5000 cd m -2 without degradation of brightness. In addition, a whispering-gallery-mode cavity and exciton-exciton interaction in the perovskite microplatelets have both been observed that can be potentially useful for achieving electrically driven laser diodes based on single-crystalline organometal halide perovskite semiconductors.

  15. A novel aptasensor based on single-molecule force spectroscopy for highly sensitive detection of mercury ions.

    Science.gov (United States)

    Li, Qing; Michaelis, Monika; Wei, Gang; Colombi Ciacchi, Lucio

    2015-08-07

    We have developed a novel aptasensor based on single-molecule force spectroscopy (SMFS) capable of detecting mercury ions (Hg(2+)) with sub-nM sensitivity. The single-strand (ss) DNA aptamer used in this work is rich in thymine (T) and readily forms T-Hg(2+)-T complexes in the presence of Hg(2+). The aptamer was conjugated to an atomic force microscope (AFM) probe, and the adhesion force between the probe and a flat graphite surface was measured by single-molecule force spectroscopy (SMFS). The presence of Hg(2+) ions above a concentration threshold corresponding to the affinity constant of the ions for the aptamer (about 5 × 10(9) M(-1)) could be easily detected by a change of the measured adhesion force. With our chosen aptamer, we could reach an Hg(2+) detection limit of 100 pM, which is well below the maximum allowable level of Hg(2+) in drinking water. In addition, this aptasensor presents a very high selectivity for Hg(2+) over other metal cations, such as K(+), Ca(2+), Zn(2+), Fe(2+), and Cd(2+). Furthermore, the effects of the ionic strength and loading rate on the Hg(2+) detection were evaluated. Its simplicity, reproducibility, high selectivity and sensitivity make our SMFS-based aptasensor advantageous with respect to other current Hg(2+) sensing methods. It is expected that our strategy can be exploited for monitoring the pollution of water environments and the safety of potentially contaminated food.

  16. Quantum phase transitions driven by rhombic-type single-ion anisotropy in the S =1 Haldane chain

    Science.gov (United States)

    Tzeng, Yu-Chin; Onishi, Hiroaki; Okubo, Tsuyoshi; Kao, Ying-Jer

    2017-08-01

    The spin-1 Haldane chain is an example of the symmetry-protected-topological (SPT) phase in one dimension. Experimental realization of the spin chain materials usually involves both the uniaxial-type, D (Sz)2 , and the rhombic-type, E [(Sx)2-(Sy)2] , single-ion anisotropies. Here, we provide a precise ground-state phase diagram for a spin-1 Haldane chain with these single-ion anisotropies. Using quantum numbers, we find that the Z2 symmetry breaking phase can be characterized by double degeneracy in the entanglement spectrum. Topological quantum phase transitions take place on particular paths in the phase diagram, from the Haldane phase to the large-Ex, large-Ey, or large-D phases. The topological critical points are determined by the level spectroscopy method with a newly developed parity technique in the density matrix renormalization group [Phys. Rev. B 86, 024403 (2012), 10.1103/PhysRevB.86.024403], and the Haldane-large-D critical point is obtained with an unprecedented precision, (D/J ) c=0.9684713 (1 ) . Close to this critical point, a small rhombic single-ion anisotropy |E |/J ≪1 can destroy the Haldane phase and bring the system into a y -Néel phase. We propose that the compound [Ni (HF2) (3-Clpy ) 4] BF4 is a candidate system to search for the y -Néel phase.

  17. EPR and optical absorption studies of paramagnetic molecular ion (VO2+) in Lithium Sodium Acid Phthalate single crystal

    Science.gov (United States)

    Subbulakshmi, N.; Kumar, M. Saravana; Sheela, K. Juliet; Krishnan, S. Radha; Shanmugam, V. M.; Subramanian, P.

    2017-12-01

    Electron Paramagnetic Resonance (EPR) spectroscopic studies of VO2+ ions as paramagnetic impurity in Lithium Sodium Acid Phthalate (LiNaP) single crystal have been done at room temperature on X-Band microwave frequency. The lattice parameter values are obtained for the chosen system from Single crystal X-ray diffraction study. Among the number of hyperfine lines in the EPR spectra only two sets are reported from EPR data. The principal values of g and A tensors are evaluated for the two different VO2+ sites I and II. They possess the crystalline field around the VO2+ as orthorhombic. Site II VO2+ ion is identified as substitutional in place of Na1 location and the other site I is identified as interstitial location. For both sites in LiNaP, VO2+ are identified in octahedral coordination with tetragonal distortion as seen from the spin Hamiltonian parameter values. The ground state of vanadyl ion in the LiNaP single crystal is dxy. Using optical absorption data the octahedral and tetragonal parameters are calculated. By correlating EPR and optical data, the molecular orbital bonding parameters have been discussed for both sites.

  18. Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

    Science.gov (United States)

    Nelson, Peter Hugo

    2003-12-01

    The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

  19. Thermal stability and modeling of lithium ion batteries

    Science.gov (United States)

    Botte, Gerardine Gabriela

    2000-10-01

    First-principles mathematical models were developed to examine the effect of the lithium-lithium ion interactions inside the anode particles on the performance of a lithium foil cell. Two different models were developed: the chemical potential model (CPM) that includes the lithium-lithium ion interactions inside the anode particles and the diffusion model (DIM) that does not include the interactions. Significant differences in the thermal and electrochemical performance of the cell were observed between the two approaches. The temperature of the cell predicted by the DFM is higher than the one predicted by the CPM at a given capacity. The discharge time of the cell predicted by the DFM is shorter than the one predicted by the CPM. The results indicate that the cell needs to be modeled using the CPM approach especially at high discharge rates. An evaluation of the numerical techniques, control volume formulation (CVF) and finite difference method (FDM), used for the models was performed. It is shown that the truncation error is the same for both methods when the boundary conditions are of the Dirichlet type, the system of equations are linear and represented in Cartesian coordinates. A new technique to analyze the accuracy of the methods is presented. The only disadvantage of the FDM is that it failed to conserve mass for a small number of nodes when both boundary conditions include a derivative term whereas the CVF did conserve mass for these cases. However, for a large number of nodes the FDM provides mass conservation. It is important to note that the CVF has only (DeltaX) order of accuracy for a Neumann type boundary condition whereas the FDM has (DeltaX) 2 order. The second topic of this dissertation presents a study of the thermal stability of LiPF6 EC:EMC electrolyte for lithium ion batteries. A differential scanning calorimeter (DSC) was used to perform the study of the electrolyte. For first time, the effect of different variables on its thermal stability

  20. A collisional radiative model of hydrogen plasmas developed for diagnostic purposes of negative ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Iordanova, Snejana, E-mail: snejana@phys.uni-sofia.bg; Paunska, Tsvetelina [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria)

    2016-02-15

    A collisional radiative model of low-pressure hydrogen plasmas is elaborated and applied in optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The model accounts for the main processes determining both the population densities of the first ten states of the hydrogen atom and the densities of the positive hydrogen ions H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +}. In the calculations, the electron density and electron temperature are varied whereas the atomic and molecular temperatures are included as experimentally obtained external parameters. The ratio of the H{sub α} to H{sub β} line intensities is calculated from the numerical results for the excited state population densities, obtained as a solution of the set of the steady-state rate balance equations. The comparison of measured and theoretically obtained ratios of line intensities yields the values of the electron density and temperature as well as of the degree of dissociation, i.e., of the parameters which have a crucial role for the volume production of the negative ions.

  1. Comparison of string models for heavy ion collisions

    International Nuclear Information System (INIS)

    Werner, K.

    1990-01-01

    An important method to explore new domains in physics is to compare new results with extrapolations from known areas. For heavy ion collision this can be done with string models, which extrapolate from light to heavy systems and which also may be used to extrapolate to higher energies. That does not mean that these string models are only background models, one may easily implement new ideas on top of the known aspects, providing much more reliable models than those formed from scratch. All the models to be considered in this paper have in common that they consist of three independent building blocks: (a) geometry, (b) string formation and (c) string fragmentation. The geometry aspect is treated quite similar in all models: nucleons are distributed inside each nucleus according to some standard parameterization of nuclear densities. The nuclei move through each other on a straight line trajectory, with all the nucleon positions being fixed. Whenever a projectile and a target nucleon come close, they interact. Such an interaction results in string formation. In the last step these strings decay into observable hadrons according to some string fragmentation procedure. The three building blocks are independent, so one can combine different methods in an arbitrary manner. Therefore rather than treating the models one after the other, the author discusses the procedures for string formation and string fragmentation as used by the models. He considers string models in a very general sense, so he includes models where the authors never use the word string, but which may be most naturally interpreted as string models and show strong similarities with real string models. Although very important he does not discuss - for time and space reasons - recent developments concerning secondary scattering

  2. SPICE Modeling of Single-Grain Si TFTs using BSIMSOI

    NARCIS (Netherlands)

    Baiano, A.; Ishihara, R.; Saputra, N.; Long, J.; Karaki, N.; Inoue, S.; Metselaar, W.; Beenakker, C.I.M.

    2007-01-01

    Single Grain Thin-film transistors (SG-TFTs) fabricated inside a location-controlled grain by µ-Czochralski process have as high as SOI performance. To model them, BSIMSOI with a proper modification of the mobility is proposed. The model has been verified for n- and p-channel DC and low frequency AC

  3. Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

    International Nuclear Information System (INIS)

    King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T.; Tuna, Floriana; McInnes, Eric J.L.

    2013-01-01

    Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). [de

  4. Self-consistent modeling of electron cyclotron resonance ion sources

    International Nuclear Information System (INIS)

    Girard, A.; Hitz, D.; Melin, G.; Serebrennikov, K.; Lecot, C.

    2004-01-01

    In order to predict the performances of electron cyclotron resonance ion source (ECRIS), it is necessary to perfectly model the different parts of these sources: (i) magnetic configuration; (ii) plasma characteristics; (iii) extraction system. The magnetic configuration is easily calculated via commercial codes; different codes also simulate the ion extraction, either in two dimension, or even in three dimension (to take into account the shape of the plasma at the extraction influenced by the hexapole). However the characteristics of the plasma are not always mastered. This article describes the self-consistent modeling of ECRIS: we have developed a code which takes into account the most important construction parameters: the size of the plasma (length, diameter), the mirror ratio and axial magnetic profile, whether a biased probe is installed or not. These input parameters are used to feed a self-consistent code, which calculates the characteristics of the plasma: electron density and energy, charge state distribution, plasma potential. The code is briefly described, and some of its most interesting results are presented. Comparisons are made between the calculations and the results obtained experimentally

  5. Self-consistent modeling of electron cyclotron resonance ion sources

    Science.gov (United States)

    Girard, A.; Hitz, D.; Melin, G.; Serebrennikov, K.; Lécot, C.

    2004-05-01

    In order to predict the performances of electron cyclotron resonance ion source (ECRIS), it is necessary to perfectly model the different parts of these sources: (i) magnetic configuration; (ii) plasma characteristics; (iii) extraction system. The magnetic configuration is easily calculated via commercial codes; different codes also simulate the ion extraction, either in two dimension, or even in three dimension (to take into account the shape of the plasma at the extraction influenced by the hexapole). However the characteristics of the plasma are not always mastered. This article describes the self-consistent modeling of ECRIS: we have developed a code which takes into account the most important construction parameters: the size of the plasma (length, diameter), the mirror ratio and axial magnetic profile, whether a biased probe is installed or not. These input parameters are used to feed a self-consistent code, which calculates the characteristics of the plasma: electron density and energy, charge state distribution, plasma potential. The code is briefly described, and some of its most interesting results are presented. Comparisons are made between the calculations and the results obtained experimentally.

  6. Simulating discrete models of pattern formation by ion beam sputtering

    International Nuclear Information System (INIS)

    Hartmann, Alexander K; Kree, Reiner; Yasseri, Taha

    2009-01-01

    A class of simple, (2+1)-dimensional, discrete models is reviewed, which allow us to study the evolution of surface patterns on solid substrates during ion beam sputtering (IBS). The models are based on the same assumptions about the erosion process as the existing continuum theories. Several distinct physical mechanisms of surface diffusion are added, which allow us to study the interplay of erosion-driven and diffusion-driven pattern formation. We present results from our own work on evolution scenarios of ripple patterns, especially for longer timescales, where nonlinear effects become important. Furthermore we review kinetic phase diagrams, both with and without sample rotation, which depict the systematic dependence of surface patterns on the shape of energy depositing collision cascades after ion impact. Finally, we discuss some results from more recent work on surface diffusion with Ehrlich-Schwoebel barriers as the driving force for pattern formation during IBS and on Monte Carlo simulations of IBS with codeposition of surfactant atoms.

  7. Nanometer-size surface modification produced by single, low energy, highly charged ions

    International Nuclear Information System (INIS)

    Stockli, M.P.

    1994-01-01

    Atomically flat surfaces of insulators have been bombarded with low energy, highly charged ions to search for nanometer-size surface modifications. It is expected that the high electron deficiency of highly charged ions will capture and/or remove many of the insulator's localized electrons when impacting on an insulating surface. The resulting local electron deficiency is expected to locally disintegrate the insulator through a open-quotes Coulomb explosionclose quotes forming nanometer-size craters. Xe ions with charge states between 10+ and 45+ and kinetic energies between 0 and 10 keV/q were obtained from the KSU-CRYEBIS, a CRYogenic Electron Beam Ion Source and directed onto various insulating materials. Mica was favored as target material as atomically flat surfaces can be obtained reliably through cleaving. However, the authors observations with an atomic force microscope have shown that mica tends to defoliate locally rather than disintegrate, most likely due to the small binding forces between adjacent layers. So far the authors measurements indicate that each ion produces one blister if the charge state is sufficiently high. The blistering does not seem to depend very much on the kinetic energy of the ions

  8. Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model

    Science.gov (United States)

    Strigari, L.; Torriani, F.; Manganaro, L.; Inaniwa, T.; Dalmasso, F.; Cirio, R.; Attili, A.

    2018-03-01

    Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

  9. 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.

  10. AC impedance electrochemical modeling of lithium-ion positive electrodes

    International Nuclear Information System (INIS)

    Dees, D.; Gunen, E.; Abraham, D.; Jansen, A.; Prakash, J.

    2004-01-01

    Under Department of Energy's Advanced Technology Development Program,various analytical diagnostic studies are being carried out to examine the lithium-ion battery technology for hybrid electric vehicle applications, and a series of electrochemical studies are being conducted to examine the performance of these batteries. An electrochemical model was developed to associate changes that were observed in the post-test analytical diagnostic studies with the electrochemical performance loss during testing of lithium ion batteries. While both electrodes in the lithium-ion cell have been studied using a similar electrochemical model, the discussion here is limited to modeling of the positive electrode. The positive electrode under study has a composite structure made of a layered nickel oxide (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) active material, a carbon black and graphite additive for distributing current, and a PVDF binder all on an aluminum current collector. The electrolyte is 1.2M LiPF 6 dissolved in a mixture of EC and EMC and a Celgard micro-porous membrane is used as the separator. Planar test cells (positive/separator/negative) were constructed with a special fixture and two separator membranes that allowed the placement of a micro-reference electrode between the separator membranes (1). Electrochemical studies including AC impedance spectroscopy were then conducted on the individual electrodes to examine the performance and ageing effects in the cell. The model was developed by following the work of Professor Newman at Berkeley (2). The solid electrolyte interface (SEI) region, based on post-test analytical results, was assumed to be a film on the oxide and an oxide layer at the surface of the oxide. A double layer capacity was added in parallel with the Butler-Volmer kinetic expression. The pertinent reaction, thermodynamic, and transport equations were linearized for a small sinusoidal perturbation (3). The resulting system of differential equations was solved

  11. Heavy ion collision evolution modeling with ECHO-QGP

    Science.gov (United States)

    Rolando, V.; Inghirami, G.; Beraudo, A.; Del Zanna, L.; Becattini, F.; Chandra, V.; De Pace, A.; Nardi, M.

    2014-11-01

    We present a numerical code modeling the evolution of the medium formed in relativistic heavy ion collisions, ECHO-QGP. The code solves relativistic hydrodynamics in (3 + 1)D, with dissipative terms included within the framework of Israel-Stewart theory; it can work both in Minkowskian and in Bjorken coordinates. Initial conditions are provided through an implementation of the Glauber model (both Optical and Monte Carlo), while freezeout and particle generation are based on the Cooper-Frye prescription. The code is validated against several test problems and shows remarkable stability and accuracy with the combination of a conservative (shock-capturing) approach and the high-order methods employed. In particular it beautifully agrees with the semi-analytic solution known as Gubser flow, both in the ideal and in the viscous Israel-Stewart case, up to very large times and without any ad hoc tuning of the algorithm.

  12. Biological effectiveness and application of heavy ions in radiation therapy described by a physical and biological model

    International Nuclear Information System (INIS)

    Olsen, K.J.; Hansen, J.W.

    1982-12-01

    A description is given of the physical basis for applying track structure theory in the determination of the effectiveness of heavy-ion irradiation of single- and multi-hit target systems. It will be shown that for applying the theory to biological systems the effectiveness of heavy-ion irradiation is inadequately described by an RBE-factor, whereas the complete formulation of the probability of survival must be used, as survival depends on both radiation quality and dose. The theoretical model of track structure can be used in dose-effect calculations for neutron-, high-LET, and low-LET radiation applied simultaneously in therapy. (author)

  13. Ground-state phase diagram of an (S, S') = (1, 2) spin-alternating chain with competing single-ion anisotropies

    International Nuclear Information System (INIS)

    Tonegawa, T; Okamoto, K; Sakai, T; Kaburagi, M

    2009-01-01

    Employing various numerical methods, we determine the ground-state phase diagram of an (S, S') = (1, 2) spin-alternating chain with antiferromagnetic nearest-neighboring exchange interactions and uniaxial single-ion anisotropies. The resulting phase diagram consists of eight kinds of phases including two phases which accompany the spontaneous breaking of the translational symmetry and a ferrimagnetic phase in which the ground-state magnetization varies continuously with the uniaxial single-ion anisotropy constants for the S=1 and S =2 spins. The appearance of these three phases is attributed to the competition between the uniaxial single-ion anisotropies of both spins.

  14. Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

    Energy Technology Data Exchange (ETDEWEB)

    King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Tuna, Floriana; McInnes, Eric J.L. [School of Chemistry and Photon Science Institute, University of Manchester (United Kingdom)

    2013-04-26

    Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

    International Nuclear Information System (INIS)

    King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T.; Tuna, Floriana; McInnes, Eric J.L.

    2013-01-01

    Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Crystal Growth and Spectroscopic characterization of chloride and bromide single crystals doped with rare earth ions for the mid infrared amplification

    International Nuclear Information System (INIS)

    Ferrier, A.

    2007-12-01

    This work is devoted to the study of low phonon energy crystals doped with rare earth ions for the realisation of diode-pumped solid state laser sources emitting in the middle infrared. For that purpose, pure and (Er 3+ or Pr 3+ ) doped single crystals of KPb 2 Cl 5 and Tl 3 PbX 5 (X=Cl, Br) have been elaborated by using the Bridgman-Stockbarger method. These non-hygroscopic and congruent melting materials have been found to exhibit phase transitions during the cooling process but which do not limit the elaboration of centimeter-size single crystals. The spectroscopic study of the Er 3+ doped compounds has been performed both at high and low temperatures. It thus appears that these systems present long fluorescence lifetimes and relatively large gain cross sections favorable for a laser emission around 4.5μm. It has been demonstrated further that the up-conversion processes resulting from excited-state absorptions of the Er 3+ ions around the pumping wavelength as well as the energy transfer processes between the Er 3+ ions do not lead to significant optical losses for the laser system. The derived parameters then have been used to build a model and simulate the laser operation of the system following diode pumping around 800 nm. In the end, the spectroscopic study of the Pr 3+ ion in various materials has allowed us to evidence large emission cross sections associated with long fluorescence lifetimes, now favorable to a laser emission around 5μm. (author)

  17. Characteristics and properties of nano-LiCoO2 synthesized by pre-organized single source precursors: Li-ion diffusivity, electrochemistry and biological assessment.

    Science.gov (United States)

    Brog, Jean-Pierre; Crochet, Aurélien; Seydoux, Joël; Clift, Martin J D; Baichette, Benoît; Maharajan, Sivarajakumar; Barosova, Hana; Brodard, Pierre; Spodaryk, Mariana; Züttel, Andreas; Rothen-Rutishauser, Barbara; Kwon, Nam Hee; Fromm, Katharina M

    2017-08-22

    LiCoO 2 is one of the most used cathode materials in Li-ion batteries. Its conventional synthesis requires high temperature (>800 °C) and long heating time (>24 h) to obtain the micronscale rhombohedral layered high-temperature phase of LiCoO 2 (HT-LCO). Nanoscale HT-LCO is of interest to improve the battery performance as the lithium (Li + ) ion pathway is expected to be shorter in nanoparticles as compared to micron sized ones. Since batteries typically get recycled, the exposure to nanoparticles during this process needs to be evaluated. Several new single source precursors containing lithium (Li + ) and cobalt (Co 2+ ) ions, based on alkoxides and aryloxides have been structurally characterized and were thermally transformed into nanoscale HT-LCO at 450 °C within few hours. The size of the nanoparticles depends on the precursor, determining the electrochemical performance. The Li-ion diffusion coefficients of our LiCoO 2 nanoparticles improved at least by a factor of 10 compared to commercial one, while showing good reversibility upon charging and discharging. The hazard of occupational exposure to nanoparticles during battery recycling was investigated with an in vitro multicellular lung model. Our heterobimetallic single source precursors allow to dramatically reduce the production temperature and time for HT-LCO. The obtained nanoparticles of LiCoO 2 have faster kinetics for Li + insertion/extraction compared to microparticles. Overall, nano-sized LiCoO 2 particles indicate a lower cytotoxic and (pro-)inflammogenic potential in vitro compared to their micron-sized counterparts. However, nanoparticles aggregate in air and behave partially like microparticles.

  18. MATHEMATICAL MODELING OF ELECTROCHEMICAL PROCESSES IN LITHIUM-ION BATTERIES POTENTIALLY STREAMING METHOD

    Directory of Open Access Journals (Sweden)

    S. P. Halutin

    2014-01-01

    Full Text Available Mathematical models in the electrical parameters of physico-chemical processes in lithium-ion batteries are developed. The developed model parameters (discharge mode are identified out of family of discharging curve. By using of the parameters of this model we get the numerically model of lithium-ion battery.

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  20. Experimental study of single-electron loss by Ar{sup +} ions in rare-gas atoms

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, P.G. [Facultad de Ciencias, UNAM, Coyoacan (Mexico); Castillo, F. [Instituto de Ciencias Nucleares, UNAM, Coyoacan (Mexico); Martinez, H. [Centro de Ciencias Fisicas, UNAM, Cuernavaca, Morelos (Mexico)]. E-mail: hm@fis.unam.mx

    2001-04-28

    Absolute differential and total cross sections for single-electron loss were measured for Ar{sup +} ions on rare-gas atoms in the laboratory energy range of 1.5 to 5.0 keV. The electron loss cross sections for all the targets studied are found to be in the order of magnitude between 10{sup -19} and 10{sup -22} cm{sup 2}, and show a monotonically increasing behaviour as a function of the incident energy. The behaviour of the total single-electron loss cross sections with the atomic target number, Z{sub t}, shows different dependences as the collision energy increases. In all cases the present results display experimental evidence of saturation in the single-electron loss cross section as the atomic number of the target increases. (author)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  2. Modeling of interstitial diffusion of ion-implanted boron

    International Nuclear Information System (INIS)

    Velichko, O.I.; Knyazheva, N.V.

    2009-01-01

    A model of the interstitial diffusion of ion-implanted boron during rapid thermal annealing of silicon layers previously amorphized by implantation of germanium has been proposed. It is supposed that the boron interstitials are created continuously during annealing due to generation, dissolution, or rearrangement of the clusters of impurity atoms which are formed in the ion-implanted layers with impurity concentration above the solubility limit. The local elastic stresses arising due to the difference of boron atomic radius and atomic radius of silicon also contribute to the generation of boron interstitials. A simulation of boron redistribution during thermal annealing for 60 s at a temperature of 850 C has been carried out. The calculated profile agrees well with the experimental data. A number of the parameters of interstitial diffusion have been derived. In particular, the average migration length of nonequilibrium boron interstitials is equal to 12 nm. It was also obtained that approximately 1.94% of boron atoms were converted to the interstitial sites, participated in the fast interstitial migration, and then became immobile again transferring into a substitutional position or forming the electrically inactive complexes with crystal lattice defects. (authors)

  3. Single-ion triblock copolymer electrolytes based on poly(ethylene oxide) and methacrylic sulfonamide blocks for lithium metal batteries

    Science.gov (United States)

    Porcarelli, Luca; Aboudzadeh, M. Ali; Rubatat, Laurent; Nair, Jijeesh R.; Shaplov, Alexander S.; Gerbaldi, Claudio; Mecerreyes, David

    2017-10-01

    Single-ion conducting polymer electrolytes represent the ideal solution to reduce concentration polarization in lithium metal batteries (LMBs). This paper reports on the synthesis and characterization of single-ion ABA triblock copolymer electrolytes comprising PEO and poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) blocks, poly(LiMTFSI). Block copolymers are prepared by reversible addition-fragmentation chain transfer polymerization, showing low glass transition temperature (-55 to 7 °C) and degree of crystallinity (51-0%). Comparatively high values of ionic conductivity are obtained (up to ≈ 10-4 S cm-1 at 70 °C), combined with a lithium-ion transference number close to unity (tLi+ ≈ 0.91) and a 4 V electrochemical stability window. In addition to these promising features, solid polymer electrolytes are successfully tested in lithium metal cells at 70 °C providing long lifetime up to 300 cycles, and stable charge/discharge cycling at C/2 (≈100 mAh g-1).

  4. A Nanophase-Separated, Quasi-Solid-State Polymeric Single-Ion Conductor: Polysulfide Exclusion for Lithium–Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jinhong; Song, Jongchan; Lee, Hongkyung; Noh, Hyungjun; Kim, Yun-Jung; Kwon, Sung Hyun; Lee, Seung Geol; Kim, Hee-Tak

    2017-04-19

    Formation of soluble polysulfide (PS), which is a key feature of lithium sulfur (Li–S) batteries, provides a fast redox kinetic based on a liquid–solid mechanism; however, it imposes the critical problem of PS shuttle. Here, we address the dilemma by exploiting a solvent-swollen polymeric single-ion conductor (SPSIC) as the electrolyte medium of the Li–S battery. The SPSIC consisting of a polymeric single-ion conductor and lithium salt-free organic solvents provides Li ion hopping by forming a nanoscale conducting channel and suppresses PS shuttle according to the Donnan exclusion principle when being employed for Li–S batteries. The organic solvents at the interface of the sulfur/carbon composite and SPSIC eliminate the poor interfacial contact and function as a soluble PS reservoir for maintaining the liquid–solid mechanism. Furthermore, the quasi-solid-state SPSIC allows the fabrication of a bipolar-type stack, which promises the realization of a high-voltage and energy-dense Li–S battery.

  5. Analysis of trace inorganic anions in weak acid salts by single pump cycling-column-switching ion chromatography.

    Science.gov (United States)

    Huang, Zhongping; Ni, Chengzhu; Zhu, Zhuyi; Pan, Zaifa; Wang, Lili; Zhu, Yan

    2015-05-01

    The application of ion chromatography with the single pump cycling-column-switching technique was described for the analysis of trace inorganic anions in weak acid salts within a single run. Due to the hydrogen ions provided by an anion suppressor electrolyzing water, weak acid anions could be transformed into weak acids, existing as molecules, after passing through the suppressor. Therefore, an anion suppressor and ion-exclusion column were adopted to achieve on-line matrix elimination of weak acid anions with high concentration for the analysis of trace inorganic anions in weak acid salts. A series of standard solutions consisting of target anions of various concentrations from 0.005 to 10 mg/L were analyzed, with correlation coefficients r ≥ 0.9990. The limits of detection were in the range of 0.67 to 1.51 μg/L, based on the signal-to-noise ratio of 3 and a 25 μL injection volume. Relative standard deviations for retention time, peak area, and peak height were all less than 2.01%. A spiking study was performed with satisfactory recoveries between 90.3 and 104.4% for all anions. The chromatographic system was successfully applied to the analysis of trace inorganic anions in five weak acid salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Single-Event Effects in Power MOSFETs During Heavy Ion Irradiations Performed After Gamma-Ray Degradation

    Science.gov (United States)

    Busatto, G.; De Luca, V.; Iannuzzo, F.; Sanseverino, A.; Velardi, F.

    2013-10-01

    The robustness of commercial power metal-oxide semiconductor field-effect transistors to combined gamma-heavy ion irradiation has been investigated, evidence that the degradation of the gate oxide caused by the γ irradiation can severely corrupt the robustness to single-event effects and drastically modify the physical behavior of the device under test after the impact of a heavy ion. A decrease of the critical voltages at which destructive burnouts and gate ruptures for heavy ion impact appear, has been detected in the devices under test, which were previously irradiated with γ rays. In addition, the amount of critical voltage reduction is strictly related to the amount of the absorbed γ-ray dose. Furthermore, at the failure voltage, the behavior of the device is affected by the conduction of a current through the gate oxide. Moreover, the single-event gate rupture” of the device appears at lower voltages because of the reduction of the Fowler-Nordheim limit in the γ-irradiated devices.

  7. Simulation of ion reflection from a single crystal at grazing angles

    International Nuclear Information System (INIS)

    Karpuzov, D.S.; Armour, D.G.; Evdoimov, I.N.

    1979-01-01

    Features of ion scattering for small angles of incidence, up to about 10 0 from the surface, have been examined for 6 keV Ar + ions in a plane of incidence parallel to the direction in the nickel (110) surface. Ions scattered between the surface layer atoms, either above the surface, or slightly below the surface in the semi-channel make a significant contribution to the reflected beam. The angular dependence of experimentally measured energy spectra can be explained when these scattering events are taken into account. In this region of small elastic energy loss and long path lengths close to the surface, inelastic energy losses assume an important role in determining the energy distribution of the scattered particles. (author)

  8. Ion-beam-driven amorphization of Ca2La8(SiO4)6O2 single crystals

    International Nuclear Information System (INIS)

    Weber, W.J.; Hess, N.J.; Wang, L.M.

    1993-11-01

    Single crystals of Ca 2 La 8 (SiO 4 ) 6 O 2 , with 1% Nd substituted for La, were irradiated with 0.8 MeV Ne + and 1.5 MeV Kr + ions from 15 to 773 K. The irradiations were carried out using the HVEM-Tandem Facility at Argonne National Laboratory. The structural changes and the ion fluence for complete amorphization were determined by in situ transmission electron microscopy. The ion fluence for complete amorphization increased with temperature in two stages associated with defect annealing processes. The critical temperature for amorphization increased from ∼360 K for 0.8 MeV Ne + to ∼710 K for 1.5 MeV Kr + . During in situ annealing studies, irradiation-enhanced recrystallization was observed at 923 K. Spatially-resolved fluorescence spectra of the Nd ion excited with 488.0 mn laser excitation showed marked line-broadening toward the center of the amorphous regions. Initial measurements indicate the subtle shifts of the 9 I 9/2 groundstate energy levels can be measured by pumping directly into the excited state 4 F 3/2 manifold suggesting that the line broadening observed originates from a distribution of geometrically distorted Nd sites

  9. A single optical sensor with high sensitivity for detection of Fe{sup 3+} and CN{sup −} ions

    Energy Technology Data Exchange (ETDEWEB)

    Afshani, Jafar [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Badiei, Alireza, E-mail: abadiei@khayam.ut.ac.ir [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Nanobiomedicine Center of Excellence, Nanoscience and Nanotechnology Research Center, University of Tehran, Tehran (Iran, Islamic Republic of); Jafari, Maryam; Shayesteh, Alireza; Karimi, Mehdi; Lashgari, Negar [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Mohammadi Ziarani, Ghodsi [Department of Chemistry, Alzahra University, Tehran (Iran, Islamic Republic of)

    2016-11-15

    1,2-Bis(2-hydroxymethylphenoxy)ethane was synthesized and characterized by FT-IR and {sup 1}H NMR spectroscopy, and single crystal X-ray diffraction method. The sensing ability of the sensor was studied in the presence of different cations and anions. Following the excitation wavelengths at 275 nm in EtOH/H{sub 2}O (1:9, v/v) and 310 nm in MeCN/H{sub 2}O (1:9, v/v), two distinct emissions at 305 and 356 nm were obtained, respectively. Fe{sup 3+} and CN{sup −} ions were successfully detected in EtOH/H{sub 2}O and MeCN/H{sub 2}O mixtures, respectively. While the fluorescence intensity of the sensor quenched considerably in the presence of Fe{sup 3+} cation at 305 nm, it enhanced in the presence of CN{sup −} anion at 356 nm. Selectivity of the sensor toward these ions was verified in the presence of a variety of common interfering ions. The detection limits of Fe{sup 3+} and CN{sup −} were calculated as 5.4 × 10{sup −9} mol L{sup −1} and 1.9 × 10{sup −8} mol L{sup −1}, respectively which shows the high sensitivity of the sensor toward the target ions. Finally, the interaction of the sensor and CN{sup −} anion was determined by computational studies.

  10. Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

    Energy Technology Data Exchange (ETDEWEB)

    King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry; Tuna, Floriana; McInnes, Eric J.L. [Manchester Univ. (United Kingdom). School of Chemistry

    2013-04-26

    Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). [German] Die direkte Oxidation eines Triamidoamin-Uran(III)-Komplexes mit Trimethyl-N-oxid liefert einen terminalen Uran(V)-Mono(oxo)komplex, der das erste gesicherte Beispiel eines Uran(V)-Einzelmolekuelmagnets ist. Dieser monometallische Komplex zeigt eindeutig, dass ein starkes axiales und somit anisotropes Ligandenfeld die begrenzte magnetische Anisotropie von Uran(V) beseitigen kann.

  11. Simulation study of a rectifying bipolar ion channel: Detailed model versus reduced model

    Directory of Open Access Journals (Sweden)

    Z. Ható

    2016-02-01

    Full Text Available We study a rectifying mutant of the OmpF porin ion channel using both all-atom and reduced models. The mutant was created by Miedema et al. [Nano Lett., 2007, 7, 2886] on the basis of the NP semiconductor diode, in which an NP junction is formed. The mutant contains a pore region with positive amino acids on the left-hand side and negative amino acids on the right-hand side. Experiments show that this mutant rectifies. Although we do not know the structure of this mutant, we can build an all-atom model for it on the basis of the structure of the wild type channel. Interestingly, molecular dynamics simulations for this all-atom model do not produce rectification. A reduced model that contains only the important degrees of freedom (the positive and negative amino acids and free ions in an implicit solvent, on the other hand, exhibits rectification. Our calculations for the reduced model (using the Nernst-Planck equation coupled to Local Equilibrium Monte Carlo simulations reveal a rectification mechanism that is different from that seen for semiconductor diodes. The basic reason is that the ions are different in nature from electrons and holes (they do not recombine. We provide explanations for the failure of the all-atom model including the effect of all the other atoms in the system as a noise that inhibits the response of ions (that would be necessary for rectification to the polarizing external field.

  12. Positron bound states on hydride ions in thermochemically reduced MgO single crystals

    International Nuclear Information System (INIS)

    Monge, M.A.; Pareja, R.; Gonzalez, R.; Chen, Y.

    1996-01-01

    Positron-lifetime and Doppler-broadening techniques were used to unambiguously identify positronium hydrides in thermochemically reduced MgO crystals at low temperatures. Positrons trapped at H - ions, forming PsH, yield a lifetime of (640±40) ps, independent of temperature. Complementary evidence for this identification was provided by Doppler-broadening experiments, in which positrons were trapped at H 2- sites at low temperatures. The H 2- ions were formed via H - +e - →H 2- by the capturing of an electron released from Fe + impurity under blue-light stimulation. copyright 1996 The American Physical Society

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  14. Structural properties of as-grown and reduced Pr2CuO4 single crystals investigated by ion channeling

    International Nuclear Information System (INIS)

    Haga, T.; Abe, Y.

    1996-01-01

    Ion channeling is very sensitive to atomic arrangements and small atomic displacements in real space. Thus, in order to clarify a role of reduction for Pr 2 CuO 4 , ion channeling properties for the materials have been measured in detail. Anomalous increases of dechanneling fractions of Cu and O atoms in the reduced samples have been found. These results could not be explained by the apical oxygen model but probably suggest that O atoms in Cu-O planes are removed by reduction. Taking these results into account, correlation between lattice instability and superconductivity in the material will be discussed. (orig.)

  15. Lithium-ion battery models: a comparative study and a model-based powerline communication

    Directory of Open Access Journals (Sweden)

    F. Saidani

    2017-09-01

    Full Text Available In this work, various Lithium-ion (Li-ion battery models are evaluated according to their accuracy, complexity and physical interpretability. An initial classification into physical, empirical and abstract models is introduced. Also known as white, black and grey boxes, respectively, the nature and characteristics of these model types are compared. Since the Li-ion battery cell is a thermo-electro-chemical system, the models are either in the thermal or in the electrochemical state-space. Physical models attempt to capture key features of the physical process inside the cell. Empirical models describe the system with empirical parameters offering poor analytical, whereas abstract models provide an alternative representation. In addition, a model selection guideline is proposed based on applications and design requirements. A complex model with a detailed analytical insight is of use for battery designers but impractical for real-time applications and in situ diagnosis. In automotive applications, an abstract model reproducing the battery behavior in an equivalent but more practical form, mainly as an equivalent circuit diagram, is recommended for the purpose of battery management. As a general rule, a trade-off should be reached between the high fidelity and the computational feasibility. Especially if the model is embedded in a real-time monitoring unit such as a microprocessor or a FPGA, the calculation time and memory requirements rise dramatically with a higher number of parameters. Moreover, examples of equivalent circuit models of Lithium-ion batteries are covered. Equivalent circuit topologies are introduced and compared according to the previously introduced criteria. An experimental sequence to model a 20 Ah cell is presented and the results are used for the purposes of powerline communication.

  16. The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

    International Nuclear Information System (INIS)

    Islam, Z.

    1999-01-01

    This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi 2 Ge 2 (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi 2 Ge 2 compounds. Generalized susceptibility, χ 0 (q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi 2 Ge 2 , and the commensurate structure in EuNi 2 Ge 2 . A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T N in EuNi 2 Ge 2 than that in GdNi 2 Ge 2 is also explained. Next, all the metamagnetic phases in TbNi 2 Ge 2 with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation

  17. The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Z.

    1999-05-10

    This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi{sub 2}Ge{sub 2} (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi{sub 2}Ge{sub 2} compounds. Generalized susceptibility, {chi}{sub 0}(q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi{sub 2}Ge{sub 2}, and the commensurate structure in EuNi{sub 2}Ge{sub 2}. A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T{sub N} in EuNi{sub 2}Ge{sub 2} than that in GdNi{sub 2}Ge{sub 2} is also explained. Next, all the metamagnetic phases in TbNi{sub 2}Ge{sub 2} with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation.

  18. A high-gain, low ion-backflow double micro-mesh gaseous structure for single electron detection

    Science.gov (United States)

    Zhang, Zhiyong; Qi, Binbin; Liu, Chengming; Feng, Jianxin; Liu, Jianbei; Shao, Ming; Zhou, Yi; Hong, Daojin; Lv, You; Song, Guofeng; Wang, Xu; You, Wenhao

    2018-05-01

    Application of micro-pattern gaseous detectors to gaseous photomultiplier tubes has been widely investigated over the past two decades. In this paper, we present a double micro-mesh gaseous structure that has been designed and fabricated for this application. Tests with X-rays and UV laser light indicate that this structure exhibits an excellent gas gain of > 7 × 104 and good energy resolution of 19% (full width at half maximum) for 5.9 keV X-rays. The gas gain can reach up to 106 for single electrons while maintaining a very low ion-backflow ratio down to 0.0005. This structure has good potential for other applications requiring a very low level of ion backflow.

  19. Single-crystalline LiFePO4 nanosheets for high-rate Li-ion batteries.

    Science.gov (United States)

    Zhao, Yu; Peng, Lele; Liu, Borui; Yu, Guihua

    2014-05-14

    The lithiation/delithiation in LiFePO4 is highly anisotropic with lithium-ion diffusion being mainly confined to channels along the b-axis. Controlling the orientation of LiFePO4 crystals therefore plays an important role for efficient mass transport within this material. We report here the preparation of single crystalline LiFePO4 nanosheets with a large percentage of highly oriented {010} facets, which provide the highest pore density for lithium-ion insertion/extraction. The LiFePO4 nanosheets show a high specific capacity at low charge/discharge rates and retain significant capacities at high C-rates, which may benefit the development of lithium batteries with both favorable energy and power density.

  20. Modelling early stages of relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Ruggieri M.

    2016-01-01

    Full Text Available In this study we model early time dynamics of relativistic heavy ion collisions by an initial color-electric field which then decays to a plasma by the Schwinger mechanism. The dynamics of the many particles system produced by the decay is described by relativistic kinetic theory, taking into account the backreaction on the color field by solving self-consistently the kinetic and the field equations. Our main results concern isotropization and thermalization for a 1+1D expanding geometry. In case of small η/s (η/s ≲ 0.3 we find τisotropization ≈ 0.8 fm/c and τthermalization ≈ 1 fm/c in agreement with the common lore of hydrodynamics.

  1. Application of Ann for Prediction of Co2+, Cd2+ and Zn2+ Ions Uptake by R. Squarrosus Biomass in Single and Binary Mixtures

    Directory of Open Access Journals (Sweden)

    Nemeček Peter

    2014-06-01

    Full Text Available Discharge of heavy metals into aquatic ecosystems has become a matter of concern over the last few decades. The search for new technologies involving the removal of toxic metals from wastewaters has directed the attention to biosorption, based on metal binding capacities of various biological materials. Degree of sorbent affinity for the sorbate determines its distribution between the solid and liquid phases and this behavior can be described by adsorption isotherm models (Freundlich and Langmuir isotherm models representing the classical approach. In this study, an artificial neural network (ANN was proposed to predict the sorption efficiency in single and binary component solutions of Cd2+, Zn2+ and Co2+ ions by biosorbent prepared from biomass of moss Rhytidiadelphus squarrosus. Calculated non-linear ANN models presented in this paper are advantageous for its capability of successful prediction, which can be problematic in the case of classical isotherm approach. Quality of prediction was proved by strong agreement between calculated and measured data, expressed by the coefficient of determination in both, single and binary metal systems (R2= 0.996 and R2= 0.987, respectively. Another important benefit of these models is necessity of significantly smaller amount of data (about 50% for the model calculation. Also, it is possible to calculate Qeq for all studied metals by one combined ANN model, which totally overcomes a classical isotherm approach

  2. Imaging of single cells and tissue using MeV ions

    International Nuclear Information System (INIS)

    Watt, F.; Bettiol, A.A.; Kan, J.A. van; Ynsa, M.D.; Ren Minqin; Rajendran, R.; Cui Huifang; Sheu, F.-S.; Jenner, A.M.

    2009-01-01

    With the attainment of sub-100 nm high energy (MeV) ion beams, comes the opportunity to image cells and tissue at nano-dimensions. The advantage of MeV ion imaging is that the ions will penetrate whole cells, or relatively thick tissue sections, without any significant loss of resolution. In this paper, we demonstrate that whole cells (cultured N2A neuroblastoma cells ATCC) and tissue sections (rabbit pancreas tissue) can be imaged at sub-100 nm resolutions using scanning transmission ion microscopy (STIM), and that sub-cellular structural details can be identified. In addition to STIM imaging we have also demonstrated for the first time, that sub-cellular proton induced fluorescence imaging (on cultured N2A neuroblastoma cells ATCC) can also be carried out at resolutions of 200 nm, compared with 300-400 nm resolutions achieved by conventional optical fluorescence imaging. The combination of both techniques offers a potentially powerful tool in the quest for elucidating cell function, particularly when it should be possible in the near future to image down to sub-50 nm.

  3. Picomolar selective detection of mercuric ion (Hg{sup 2+}) using a functionalized single plasmonic gold nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hyeon Don; Choi, Inhee; Yang, Young In; Hong, Surin; Lee, Suseung; Yi, Jongheop [School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 151-742 (Korea, Republic of); Kang, Taewook, E-mail: xinly601@snu.ac.kr, E-mail: iniini79@snu.ac.kr, E-mail: netmo00@snu.ac.kr, E-mail: pell2004@snu.ac.kr, E-mail: jazz1863@snu.ac.kr, E-mail: twkang@sogang.ac.kr, E-mail: jyi@snu.ac.kr [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 121-742 (Korea, Republic of)

    2010-04-09

    A highly sensitive method for the selective detection and quantification of mercuric ions (Hg{sup 2+}) using single plasmonic gold nanoparticle (GNP)-based dark-field microspectroscopy (DFMS) is demonstrated. The method is based on the scattering property of a single GNP that is functionalized with thiolated molecules, which is altered when analytes bind to the functionalized GNP. The spectral resolution of the system is 0.26 nm and a linear response to Hg{sup 2+} was found in the dynamic range of 100 pM-10 {mu}M. The method permits Hg{sup 2+} to be detected at the picomolar level, which is a remarkable reduction in the detection limit, considering the currently proscribed Environmental Protection Agency regulation level (10 nM, or 2 ppb) and the detection limits of other optical methods for detecting Hg{sup 2+} (recently approx. 1-10 nM). In addition, Hg{sup 2+} can be sensitively detected in the presence of Cd{sup 2+}, Pb{sup 2+}, Cu{sup 2+}, Zn{sup 2+} and Ni{sup 2+}, which do not interfere with the analysis. Based on the findings reported herein, it is likely that single-nanoparticle-based metal ion sensing can be extended to the development of other chemo- and biosensors for the direct detection of specific targets in an intracellular environment as well as in environmental monitoring.

  4. Luminescence and Tb3+-Ce3+-Eu3+ ion energy transfer in single-crystalline films of Tb3Al5O12:Ce,Eu garnet

    International Nuclear Information System (INIS)

    Zorenko, Y.; Gorbenko, V.; Voznyak, T.; Batentschuk, M.; Osvet, A.; Winnacker, A.

    2008-01-01

    The paper is devoted to investigation of the processes of excitation energy transfer between the host cations (Tb 3+ ions) and the activators (Ce 3+ and Eu 3+ ions) in single-crystalline films of Tb 3 Al 5 O 12 :Ce,Eu (TbAG:Ce,Eu) garnet which is considered as a promising luminescent material for the conversion of LED's radiation. The cascade process of excitation energy transfer is shown to be realized in TbAG:Ce,Eu: (i) from Tb 3+ ions to Ce 3+ and Eu 3+ ions; (ii) from Ce 3+ ions to Eu 3+ ions by means of dipole-dipole interaction and through Tb 3+ ion sublattice

  5. On the Predictiveness of Single-Field Inflationary Models

    CERN Document Server

    Burgess, C.P.; Trott, Michael

    2014-01-01

    We re-examine the predictiveness of single-field inflationary models and discuss how an unknown UV completion can complicate determining inflationary model parameters from observations, even from precision measurements. Besides the usual naturalness issues associated with having a shallow inflationary potential, we describe another issue for inflation, namely, unknown UV physics modifies the running of Standard Model (SM) parameters and thereby introduces uncertainty into the potential inflationary predictions. We illustrate this point using the minimal Higgs Inflationary scenario, which is arguably the most predictive single-field model on the market, because its predictions for $A_s$, $r$ and $n_s$ are made using only one new free parameter beyond those measured in particle physics experiments, and run up to the inflationary regime. We find that this issue can already have observable effects. At the same time, this UV-parameter dependence in the Renormalization Group allows Higgs Inflation to occur (in prin...

  6. A three-scale model for ionic solute transport in swelling clays incorporating ion-ion correlation effects

    Science.gov (United States)

    Le, Tien Dung; Moyne, Christian; Murad, Marcio A.

    2015-01-01

    A new three-scale model is proposed to describe the movement of ionic species of different valences in swelling clays characterized by three separate length scales (nano, micro, and macro) and two levels of porosity (nano- and micropores). At the finest (nano) scale the medium is treated as charged clay particles saturated by aqueous electrolyte solution containing monovalent and divalent ions forming the electrical double layer. A new constitutive law is constructed for the disjoining pressure based on the numerical resolution of non-local problem at the nanoscale which, in contrast to the Poisson-Boltzmann theory for point charge ions, is capable of capturing the short-range interactions between the ions due to their finite size. At the intermediate scale (microscale), the two-phase homogenized particle/electrolyte solution system is represented by swollen clay clusters (or aggregates) with the nanoscale disjoining pressure incorporated in a modified form of Terzaghi's effective principle. At the macroscale, the electro-chemical-mechanical couplings within clay clusters is homogenized with the ion transport in the bulk fluid lying in the micro pores. The resultant macroscopic picture is governed by a three-scale model wherein ion transport takes place in the bulk solution strongly coupled with the mechanics of the clay clusters which play the role of sources/sinks of mass to the bulk fluid associated with ion adsorption/desorption in the electrical double layer at the nanoscale. Within the context of the quasi-steady version of the multiscale model, wherein the electrolyte solution in the nanopores is assumed at instantaneous thermodynamic equilibrium with the bulk fluid in the micropores, we build-up numerically the ion-adsorption isotherms along with the constitutive law of the retardation coefficients of monovalent and divalent ions. In addition, the constitutive law for the macroscopic swelling pressure is reconstructed numerically showing patterns of

  7. ModFossa: A library for modeling ion channels using Python.

    Science.gov (United States)

    Ferneyhough, Gareth B; Thibealut, Corey M; Dascalu, Sergiu M; Harris, Frederick C

    2016-06-01

    The creation and simulation of ion channel models using continuous-time Markov processes is a powerful and well-used tool in the field of electrophysiology and ion channel research. While several software packages exist for the purpose of ion channel modeling, most are GUI based, and none are available as a Python library. In an attempt to provide an easy-to-use, yet powerful Markov model-based ion channel simulator, we have developed ModFossa, a Python library supporting easy model creation and stimulus definition, complete with a fast numerical solver, and attractive vector graphics plotting.

  8. Radiation-induced effects in MgO single crystal by 200 keV and 1 MeV Ni ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Nakai, Yoshihiro; Hamaguchi, Dai [Kyoto Inst. of Tech. (Japan); and others

    1997-03-01

    MgO(100) single crystals were implanted with 1.0 MeV and 200 keV Ni ions between 10{sup 15} and 10{sup 17} ions/cm{sup 2} at room temperature. Before and after thermal annealing the radiation damage and the lattice location of implanted Ni ions were analyzed by using Rutherford backscattering spectrometry with channeling and optical absorption measurements. For 1.0 MeV Ni ions, the disorder of Mg atoms increased slowly with ion dose near surface region, while it increased sharply and saturated with ion dose from 2x10{sup 16} ions/cm{sup 2} near ion range. The radiation damage was recovered and implanted Ni ions diffused to the whole of crystal and occupied substitutional positions after 1400degC annealing. For 200 keV Ni ions, the disorder of Mg atoms increased with dose near ion range and had a maximum at about 5x10{sup 16} ions/cm{sup 2}. This tendency agrees with the behavior of color centers obtained from optical measurements. For thermal annealing the radiation damage did not change during 500degC annealing, but the aggregate centers appeared after 300degC annealing. (author)

  9. Ion current prediction model considering columnar recombination in alpha radioactivity measurement using ionized air transportation

    International Nuclear Information System (INIS)

    Naito, Susumu; Hirata, Yosuke; Izumi, Mikio; Sano, Akira; Miyamoto, Yasuaki; Aoyama, Yoshio; Yamaguchi, Hiromi

    2007-01-01

    We present a reinforced ion current prediction model in alpha radioactivity measurement using ionized air transportation. Although our previous model explained the qualitative trend of the measured ion current values, the absolute values of the theoretical curves were about two times as large as the measured values. In order to accurately predict the measured values, we reinforced our model by considering columnar recombination and turbulent diffusion, which affects columnar recombination. Our new model explained the considerable ion loss in the early stage of ion diffusion and narrowed the gap between the theoretical and measured values. The model also predicted suppression of ion loss due to columnar recombination by spraying a high-speed air flow near a contaminated surface. This suppression was experimentally investigated and confirmed. In conclusion, we quantitatively clarified the theoretical relation between alpha radioactivity and ion current in laminar flow and turbulent pipe flow. (author)

  10. Modelling the many-body dynamics of heavy ion collisions. Present status and future perspective

    International Nuclear Information System (INIS)

    Hartnack, Ch.; Puri, R.K.; Aichelin, J.; Konopka, J.; Bass, S.A.; Stoecker, H.; Greiner, W.

    1996-01-01

    Basic problems of the semiclassical microscopic modelling of strongly interacting systems are discussed within the framework of Quantum Molecular Dynamics (QMD). It is shown that the same predictions can be obtained with several - numerically completely different and independently written -programs as far as the same model parameters are employed and the same basic approximations are made. Some of the physical results, however, depend also on rather technical parameters like the preparation of the initial configuration in phase space. This crucial problem is connected with the description of the ground state of single nuclei, which differs among the various approaches. An outlook to an improved molecular dynamics scheme for heavy ion collisions is given. (author)

  11. Modelling the many-body dynamics of heavy ion collisions. Present status and future perspective

    Energy Technology Data Exchange (ETDEWEB)

    Hartnack, Ch.; Puri, R.K.; Aichelin, J. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Physique Subatomique et des Technologies Associees; Konopka, J.; Bass, S.A.; Stoecker, H.; Greiner, W. [Johann Wolfgang Goethe Univ., Frankfurt am Main (Germany). Inst. fuer Theoretische Physik

    1996-12-31

    Basic problems of the semiclassical microscopic modelling of strongly interacting systems are discussed within the framework of Quantum Molecular Dynamics (QMD). It is shown that the same predictions can be obtained with several - numerically completely different and independently written -programs as far as the same model parameters are employed and the same basic approximations are made. Some of the physical results, however, depend also on rather technical parameters like the preparation of the initial configuration in phase space. This crucial problem is connected with the description of the ground state of single nuclei, which differs among the various approaches. An outlook to an improved molecular dynamics scheme for heavy ion collisions is given. (author). 86 refs.

  12. Single-particle spectral density of the Hubbard model

    NARCIS (Netherlands)

    Mehlig, B.; Eskes, H.; Hayn, R.; Meinders, M.B.J.

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  13. SINGLE-PARTICLE SPECTRAL DENSITY OF THE HUBBARD-MODEL

    NARCIS (Netherlands)

    MEHLIG, B; ESKES, H; HAYN, R; MEINDERS, MBJ

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  14. Modeling single cell antibody excretion on a biosensor

    NARCIS (Netherlands)

    Stojanovic, Ivan; Baumgartner, W.; van der Velden, T.J.G.; Terstappen, Leonardus Wendelinus Mathias Marie; Schasfoort, Richardus B.M.

    2016-01-01

    We simulated, using Comsol Multiphysics, the excretion of antibodies by single hybridoma cells and their subsequent binding on a surface plasmon resonance imaging (SPRi) sensor. The purpose was to confirm that SPRi is suitable to accurately quantify antibody (anti-EpCAM) excretion. The model showed

  15. Single-Index Additive Vector Autoregressive Time Series Models

    KAUST Repository

    LI, YEHUA; GENTON, MARC G.

    2009-01-01

    We study a new class of nonlinear autoregressive models for vector time series, where the current vector depends on single-indexes defined on the past lags and the effects of different lags have an additive form. A sufficient condition is provided

  16. Modeling single versus multiple systems in implicit and explicit memory.

    Science.gov (United States)

    Starns, Jeffrey J; Ratcliff, Roger; McKoon, Gail

    2012-04-01

    It is currently controversial whether priming on implicit tasks and discrimination on explicit recognition tests are supported by a single memory system or by multiple, independent systems. In a Psychological Review article, Berry and colleagues used mathematical modeling to address this question and provide compelling evidence against the independent-systems approach. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Interpolation solution of the single-impurity Anderson model

    International Nuclear Information System (INIS)

    Kuzemsky, A.L.

    1990-10-01

    The dynamical properties of the single-impurity Anderson model (SIAM) is studied using a novel Irreducible Green's Function method (IGF). The new solution for one-particle GF interpolating between the strong and weak correlation limits is obtained. The unified concept of relevant mean-field renormalizations is indispensable for strong correlation limit. (author). 21 refs

  18. Discrete dislocation plasticity modeling of short cracks in single crystals

    NARCIS (Netherlands)

    Deshpande, VS; Needleman, A; Van der Giessen, E

    2003-01-01

    The mode-I crack growth behavior of geometrically similar edge-cracked single crystal specimens of varying size subject to both monotonic and cyclic axial loading is analyzed using discrete dislocation dynamics. Plastic deformation is modeled through the motion of edge dislocations in an elastic

  19. Effective single scattering albedo estimation using regional climate model

    CSIR Research Space (South Africa)

    Tesfaye, M

    2011-09-01

    Full Text Available In this study, by modifying the optical parameterization of Regional Climate model (RegCM), the authors have computed and compared the Effective Single-Scattering Albedo (ESSA) which is a representative of VIS spectral region. The arid, semi...

  20. Crystal-field analysis of U3+ ions in K2LaX5 (X=Cl, Br or I) single crystals

    Science.gov (United States)

    Karbowiak, M.; Edelstein, N.; Gajek, Z.; Drożdżyński, J.

    1998-11-01

    An analysis of low temperature absorption spectra of U3+ ions doped in K2LaX5 (X=Cl, Br or I) single crystals is reported. The energy levels of the U3+ ion in the single crystals were assigned and fitted to a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions at the Cs symmetry site. An analysis of the nephelauxetic effect and crystal-field splittings in the series of compounds is also reported.