International Nuclear Information System (INIS)
Davidson, Ronald C.; Efthimion, Philip C.; Gilson, Erik; Majeski, Richard; Qin, Hong
2002-01-01
The Paul Trap Simulator Experiment (PTSX) is under construction at the Princeton Plasma Physics Laboratory to simulate intense beam propagation through a periodic quadrupole magnetic field. In the Paul trap configuration, a long nonneutral plasma column is confined axially by dc voltages on end cylinders at z=+L and z=-L, and transverse confinement is provided by segmented cylindrical electrodes with applied oscillatory voltages ±V 0 (t) over 90 deg. segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the Paul trap configuration offers the possibility of simulating intense beam propagation in a compact laboratory facility. The experimental layout is described, together with the planned experiments to study beam mismatch, envelope instabilities, halo particle production, and collective wave excitations
Davidson, Ronald C.; Efthimion, Philip C.; Gilson, Erik; Majeski, Richard; Qin, Hong
2002-01-01
The Paul Trap Simulator Experiment (PTSX) is under construction at the Princeton Plasma Physics Laboratory to simulate intense beam propagation through a periodic quadrupole magnetic field. In the Paul trap configuration, a long nonneutral plasma column is confined axially by dc voltages on end cylinders at z=+L and z=-L, and transverse confinement is provided by segmented cylindrical electrodes with applied oscillatory voltages ±V0(t) over 90° segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the Paul trap configuration offers the possibility of simulating intense beam propagation in a compact laboratory facility. The experimental layout is described, together with the planned experiments to study beam mismatch, envelope instabilities, halo particle production, and collective wave excitations.
Simulating the Long-Distance Propagation of Intense Beams in the Paul Trap Simulator Experiment
Gilson, Erik P; Davidson, Ronald C; Efthimion, Philip; Majeski, Richard; Startsev, Edward
2005-01-01
The Paul Trap Simulator Experiment (PTSX) makes use of a compact Paul trap configuration with quadrupolar oscillating wall voltages to simulate the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient transport systems. The simulation is possible because of the similarity between the transverse dynamics of particles in the two systems. One-component pure cesium ion plasmas have been trapped that correspond to normalized intensity parameters s < 0.8, where s is the ratio of the square of the plasma frequency to twice the square of the average transverse focusing frequency. The PTSX device confines the plasma for hundreds of milliseconds, which is equivalent to beam propagation over tens of kilometers. Results are presented for experiments in which the amplitude of the oscillating confining voltage waveform has been modified as a function of time. A comparison is made between abrupt changes in amplitude and adiabatic changes in amplitude. T...
Simulation of ion behavior in an open three-dimensional Paul trap using a power series method
Energy Technology Data Exchange (ETDEWEB)
Herbane, Mustapha Said, E-mail: mherbane@hotmail.com [King Khalid University, Faculty of Science, Department of Physics, P.O. Box 9004, Abha (Saudi Arabia); Berriche, Hamid [King Khalid University, Faculty of Science, Department of Physics, P.O. Box 9004, Abha (Saudi Arabia); Laboratoire des Interfaces et Matériaux Avancés, Physics Department, College of Science, University of Monastir, 5019 Monastir (Tunisia); Abd El-hady, Alaa [King Khalid University, Faculty of Science, Department of Physics, P.O. Box 9004, Abha (Saudi Arabia); Department of Physics, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Al Shahrani, Ghadah [King Khalid University, Faculty of Science, Department of Physics, P.O. Box 9004, Abha (Saudi Arabia); Ban, Gilles; Fléchard, Xavier; Liénard, Etienne [LPC CAEN-ENSICAEN, 6 Boulevard du Marechal Juin, 14050 Caen Cedex (France)
2014-07-01
Simulations of the dynamics of ions trapped in a Paul trap with terms in the potential up to the order 10 have been carried out. The power series method is used to solve numerically the equations of motion of the ions. The stability diagram has been studied and the buffer gas cooling has been implemented by a Monte Carlo method. The dipole excitation was also included. The method has been applied to an existing trap and it has shown good agreement with the experimental results and previous simulations using other methods. - Highlights: • Paul trap with potentials up to the order 10. • Series solution of the ions equations of motion. • Hard sphere model for the simulation of the buffer gas cooling and simulation of the dipolar excitation.
Development of Laser-Induced Fluorescence Diagnostic for the Paul Trap Simulator Experiment
Chung, Moses; Efthimion, Philip; Gilson, Erik P; Majeski, Richard; Startsev, Edward
2005-01-01
The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. For the in-situ measurement of the transverse ion density profile in the PTSX device, which is essential for the study of beam mismatch and halo particle production, a laser-induced fluorescence diagnostic system is being developed. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. The installation of the barium ion source and the characterization of the tunable dye laser system are discussed. The design of the collection optics with an intensified CCD camera system is also discussed. Finally, initial test results using the laser-induced fluorescence diagnostic will be presented.
Investigation of two-frequency Paul traps for antihydrogen production
Energy Technology Data Exchange (ETDEWEB)
Leefer, Nathan; Krimmel, Kai, E-mail: kkrimmel@students.uni-mainz.de [Helmholtz-Institut Mainz (Germany); Bertsche, William [University of Manchester (United Kingdom); Budker, Dmitry [Helmholtz-Institut Mainz (Germany); Fajans, Joel [University of California at Berkeley, Department of Physics (United States); Folman, Ron [Ben-Gurion University of the Negev, Department of Physics (Israel); Häffner, Hartmut [University of California at Berkeley, Department of Physics (United States); Schmidt-Kaler, Ferdinand [Helmholtz-Institut Mainz (Germany)
2017-11-15
Radio-frequency (rf) Paul traps operated with multifrequency rf trapping potentials provide the ability to independently confine charged particle species with widely different charge-to-mass ratios. In particular, these traps may find use in the field of antihydrogen recombination, allowing antiproton and positron clouds to be trapped and confined in the same volume without the use of large superconducting magnets. We explore the stability regions of two-frequency Paul traps and perform numerical simulations of small samples of multispecies charged-particle mixtures of up to twelve particles that indicate the promise of these traps for antihydrogen recombination.
Laser-Induced Fluorescence diagnostic of barium ion plasmas in the Paul Trap Simulator Experiment
International Nuclear Information System (INIS)
Chung, Moses; Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.
2005-01-01
The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. To investigate the ion plasma microstate in PTSX, including the ion density profile and the ion velocity distribution function, a laser-induced fluorescence diagnostic system is being developed as a nondestructive diagnostic. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. A feasibility study of the laser-induced fluorescence diagnostic using barium ions is presented with the characterization of a tunable dye laser. The installation of the barium ion source and the development of the laser-induced fluorescence diagnostic system are also discussed
Recent advances in the physics of collective excitations in the Paul trap simulator experiment
International Nuclear Information System (INIS)
Gilson, E.P.; Chung, M.; Davidson, R.C.; Dorf, M.; Efthimion, P.C.; Godbehere, A.B.; Majeski, R.
2009-01-01
The Paul trap simulator experiment (PTSX) is a compact laboratory linear Paul trap that simulates the transverse dynamics of a long charged-particle bunch propagating through a magnetic alternating-gradient (AG) transport system. The transverse dynamics of particles in the AG system in the beam's frame-of-reference and those of particles in PTSX are described by the same sets of equations, including all nonlinear space-charge effects. Initial experimental results are presented in which the collective transverse symmetric mode (m=0) and quadrupole mode (m=2) have been observed in pure-barium-ion plasmas in PTSX, with a depressed-tune ν/ν 0 ∼0.9, with the intent of identifying collective modes whose signature will serve as a robust diagnostic for key properties of the beam, such as line density and transverse emittance. The results of particle-in-cell simulations performed with the WARP code are compared to the experimental data.
Simulation of long-distance beam propagation in the Paul trap simulator experiment
International Nuclear Information System (INIS)
Gilson, Erik P.; Chung, Moses; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.
2005-01-01
The Paul Trap Simulator Experiment (PTSX) simulates the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient (AG) transport systems by making use of the similarity between the transverse dynamics of particles in the two systems. One-component pure ion plasmas have been trapped that correspond to normalized intensity parameter s-coret=ω p 2 (0)/2ω q 2 = p (r) is the plasma frequency and ω q is the average transverse focusing frequency in the smooth-focusing approximation. The PTSX device confines one-component cesium ion plasmas for hundreds of milliseconds, which is equivalent to beam propagation over 10km. Results are presented for experiments in which the amplitude of the confining voltage waveform has been modified as a function of time. Recent modifications to the device are described, and both the change from a cesium ion source to a barium ion source, and the development of a laser-induced fluorescence diagnostic system are discussed
Davidson, R C; Majeski, R; Qin, H; Shvets, G
2001-01-01
This paper describes the design concept for a compact Paul trap experimental configuration that fully simulates the collective processes and nonlinear transverse dynamics of an intense charged particle beam that propagates over large distances through a periodic quadrupole magnetic field. To summarize, a long nonneutral plasma column (L>=r sub p) is confined axially by applied DC voltages V[circ]=const. on end cylinders at z=+-L, and transverse confinement is provided by segmented cylindrical electrodes (at radius r sub w) with applied oscillatory voltages +-V sub 0 (t) over 90 deg. segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the Paul trap configuration offers the possibility of simulating intense beam propagation in a compact experimental facility. The nominal operating parameters in the experimental design are: barium ions (A=137); plasma column length 2L=2 m; wall radius r sub w =10...
Stable Trapping of Multielectron Helium Bubbles in a Paul Trap
Joseph, E. M.; Vadakkumbatt, V.; Pal, A.; Ghosh, A.
2017-06-01
In a recent experiment, we have used a linear Paul trap to store and study multielectron bubbles (MEBs) in liquid helium. MEBs have a charge-to-mass ratio (between 10^{-4} and 10^{-2} C/kg) which is several orders of magnitude smaller than ions (between 10^6 and 10^8 C/kg) studied in traditional ion traps. In addition, MEBs experience significant drag force while moving through the liquid. As a result, the experimental parameters for stable trapping of MEBs, such as magnitude and frequency of the applied electric fields, are very different from those used in typical ion trap experiments. The purpose of this paper is to model the motion of MEBs inside a linear Paul trap in liquid helium, determine the range of working parameters of the trap, and compare the results with experiments.
Microfabricated linear Paul-Straubel ion trap
Mangan, Michael A [Albuquerque, NM; Blain, Matthew G [Albuquerque, NM; Tigges, Chris P [Albuquerque, NM; Linker, Kevin L [Albuquerque, NM
2011-04-19
An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.
Cold highly charged ions in a cryogenic Paul trap
Energy Technology Data Exchange (ETDEWEB)
Versolato, O. O., E-mail: oscar.versolato@mpi-hd.mpg.de; Schwarz, M.; Windberger, A.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik (Germany); Schmidt, P. O. [Physikalisch-Technische Bundesanstalt (Germany); Drewsen, M. [University of Aarhus, Department of Physics and Astronomy (Denmark); Crespo Lopez-Urrutia, J. R. [Max-Planck-Institut fuer Kernphysik (Germany)
2013-03-15
Narrow optical transitions in highly charged ions (HCIs) are of particular interest for metrology and fundamental physics, exploiting the high sensitivity of HCIs to new physics. The highest sensitivity for a changing fine structure constant ever predicted for a stable atomic system is found in Ir{sup 17 + }. However, laser spectroscopy of HCIs is hindered by the large ({approx} 10{sup 6} K) temperatures at which they are produced and trapped. An unprecedented improvement in such laser spectroscopy can be obtained when HCIs are cooled down to the mK range in a linear Paul trap. We have developed a cryogenic linear Paul trap in which HCIs will be sympathetically cooled by {sup 9}Be{sup + } ions. Optimized optical access for laser light is provided while maintaining excellent UHV conditions. The Paul trap will be connected to an electron beam ion trap (EBIT) which is able to produce a wide range of HCIs. This EBIT will also provide the first experimental input needed for the determination of the transition energies in Ir{sup 17 + }, enabling further laser-spectroscopic investigations of this promising HCI.
Sympathetic cooling and crystallization of ions in a linear Paul trap
International Nuclear Information System (INIS)
Drewsen, M.; Bowe, P.; Hornekaer, L.; Brodersen, C.; Schiffer, J.P.; Hangst, J.S.; Schiffer, J.P.
1999-01-01
Coulomb crystals, containing up to a few hundred ions of which more than 50% were cooled sympathetically by the Coulomb interaction with laser cooled Mg + ions, have been produced in a linear Paul trap. By controlling the balance of the radiation pressure from the two cooling lasers, the Coulomb crystals could be segregated according to ion species. Previous studies of ion crystals and molecular dynamics simulations suggest that the temperature may be around 10 mK or lower. The obtained results indicate that a wide range of atomic and molecular ions, which due to their internal structures are not amenable to direct laser cooling, can be effectively cooled and localized (crystallized) in linear Paul traps. For high resolution spectroscopy of such ions this may turn out to be very useful. copyright 1999 American Institute of Physics
International Nuclear Information System (INIS)
Gilson, Erik P.; Chung, Moses; Davidson, Ronald C.; Dorf, Mikhail; Efthimion, Philip C.; Grote, David P.; Majeski, Richard; Startsev, Edward A.
2007-01-01
The Paul Trap Simulator Experiment (PTSX) is a compact laboratory Paul trap that simulates propagation of a long, thin charged-particle bunch coasting through a multi-kilometer-long magnetic alternating-gradient (AG) transport system by putting the physicist in the frame-of-reference of the beam. The transverse dynamics of particles in both systems are described by the same sets of equations-including all nonlinear space-charge effects. The time-dependent quadrupolar voltages applied to the PTSX confinement electrodes correspond to the axially dependent magnetic fields applied in the AG system. This paper presents the results of experiments in which the amplitude of the applied confining voltage is changed over the course of the experiment in order to transversely compress a beam with an initial depressed tune ν/ν 0 ∼0.9. Both instantaneous and smooth changes are considered. Particular emphasis is placed on determining the conditions that minimize the emittance growth and, generally, the number of particles that are found at large radius (so-called halo particles) after the beam compression. The experimental data are also compared with the results of particle-in-cell (PIC) simulations performed with the WARP code
Temperature measurement of {sup 6}He{sup + } ions confined in a transparent Paul trap
Energy Technology Data Exchange (ETDEWEB)
Flechard, X., E-mail: flechard@lpccaen.in2p3.fr; Ban, G.; Durand, D.; Lienard, E.; Mauger, F. [Universite de Caen, LPC Caen, ENSICAEN (France); Mery, A. [Universite de Caen, CIMAP, CEA/CNRS/ENSICAEN (France); Naviliat-Cuncic, O. [Universite de Caen, LPC Caen, ENSICAEN (France); Rodriguez, D. [Universitad de Granada, Departamento de Fisica Atomica, Molecular y Nuclear (Spain); Velten, P. [Universite de Caen, LPC Caen, ENSICAEN (France)
2011-07-15
The LPCTrap setup is a transparent Paul trap dedicated to the measurement of the {beta}-{nu} correlation coefficient a{sub {beta}{nu}} in the {beta} decay of trapped radioactive nuclides. In a first experiment, the system has been used to record {approx}10{sup 5} coincidences between the {beta} particles and recoiling ions emitted from the decay of {sup 6}He{sup + } ions. The analysis of the collected data has already shown that the size of the {sup 6}He{sup + } ion cloud confined in the Paul trap is a critical parameter, potentially limiting the accuracy on the a{sub {beta}{nu}} measurement. We report here the precise determination of the trapped ion cloud temperature and size. This was performed by extracting the trapped ions toward a position sensitive micro channel plate detector at different phases of the RF driving field. We find a temperature T{sub exp} = 0.107(7) eV, consistent with the temperature values inferred using two other observables but 20% higher than the temperature T{sub sim} = 0.09 eV predicted by realistic simulations of the ions interacting with the H{sub 2} buffer gas.
Experimental study of resonance crossing with a Paul trap
Directory of Open Access Journals (Sweden)
H. Takeuchi
2012-07-01
Full Text Available The effect of resonance crossing on beam stability is studied systematically by employing a novel tabletop experimental tool and a multiparticle simulation code. A large number of ions are confined in a compact linear Paul trap to reproduce the collective beam behavior. We can prove that the ion plasma in the trap is physically equivalent to a charged-particle beam propagating through a strong focusing channel. The plasma confinement force is quickly ramped such that the trap operating point traverses linear and nonlinear resonance stop bands. Assuming a nonscaling fixed field alternating gradient accelerator composed of many identical FODO cells, we measure how much ion losses occur under diverse conditions. It is experimentally and numerically demonstrated that too slow resonance crossing leads to significant ion losses as expected. Particular attention must be paid to the linear coherent resonance excited at a quarter-integer tune. When the beam intensity is high, this type of linear stop band can seriously affect the beam quality even for rather fast resonance crossing. A scaling law is given of the emittance growth caused by the quarter-integer resonance crossing.
The LPCTrap facility: A novel transparent Paul trap for high-precision experiments
International Nuclear Information System (INIS)
Rodriguez, D.; Mery, A.; Ban, G.; Bregeault, J.; Darius, G.; Durand, D.; Flechard, X.; Herbane, M.; Labalme, M.; Lienard, E.; Mauger, F.; Merrer, Y.; Naviliat-Cuncic, O.; Thomas, J.C.; Vandamme, C.
2006-01-01
A trap system has been built to perform high-precision β-decay experiments. The system is coupled to the low-energy beam line of the SPIRAL source at GANIL. The continuous ion beam from SPIRAL with energies between 10 and 20keV is slowed down by means of a buffer-gas-filled RFQ trap and ejected thereafter as short ion bunches into a novel transparent Paul trap. Two pulsed cavities located downstream from the RFQ reduce the energy of the ion bunch down to about a hundred eV for an efficient capture in the Paul trap. We describe here the complete system along with the first results obtained with stable He+4, Cl+35 and Ar+36,40 ions from the SPIRAL ECR source. An overall efficiency of 8.7(8)x10 -4 is achieved for 4 He + ions under specific conditions
Stability of Coulomb crystals in a linear Paul trap with storage-ring-like confinement
DEFF Research Database (Denmark)
Kjærgaard, Niels; Mølhave, Kristian; Drewsen, Michael
2002-01-01
We report experiments on the stability of ion Coulomb crystals in a linear Paul trap with storage-ring-like confinement. The transverse dynamics of charged particles in a trap of this type is analogous to that of a fast beam traveling through a channel with periodic, magnetic alternating gradient...... confinement. The experimentally observed stability conditions for stationary crystals comply remarkably well with current theory of crystalline plasmas and beams.......We report experiments on the stability of ion Coulomb crystals in a linear Paul trap with storage-ring-like confinement. The transverse dynamics of charged particles in a trap of this type is analogous to that of a fast beam traveling through a channel with periodic, magnetic alternating gradient...
Experimental simulations of beam propagation over large distances in a compact linear Paul trap
International Nuclear Information System (INIS)
Gilson, Erik P.; Chung, Moses; Davidson, Ronald C.; Dorf, Mikhail; Efthimion, Philip C.; Majeski, Richard
2006-01-01
The Paul Trap Simulator Experiment (PTSX) is a compact laboratory experiment that places the physicist in the frame of reference of a long, charged-particle bunch coasting through a kilometers-long magnetic alternating-gradient (AG) transport system. The transverse dynamics of particles in both systems are described by similar equations, including nonlinear space-charge effects. The time-dependent voltages applied to the PTSX quadrupole electrodes are equivalent to the axially oscillating magnetic fields applied in the AG system. Experiments concerning the quiescent propagation of intense beams over large distances can then be performed in a compact and flexible facility. An understanding and characterization of the conditions required for quiescent beam transport, minimum halo particle generation, and precise beam compression and manipulation techniques, are essential, as accelerators and transport systems demand that ever-increasing amounts of space charge be transported. Application areas include ion-beam-driven high energy density physics, high energy and nuclear physics accelerator systems, etc. One-component cesium plasmas have been trapped in PTSX that correspond to normalized beam intensities, s=ω p 2 (0)/2ω q 2 , up to 80% of the space-charge limit where self-electric forces balance the applied focusing force. Here, ω p (0)=[n b (0)e b 2 /m b ε 0 ] 1/2 is the on-axis plasma frequency, and ω q is the smooth-focusing frequency associated with the applied focusing field. Plasmas in PTSX with values of s that are 20% of the limit have been trapped for times corresponding to equivalent beam propagation over 10 km. Results are presented for experiments in which the amplitude of the quadrupole focusing lattice is modified as a function of time. It is found that instantaneous changes in lattice amplitude can be detrimental to transverse confinement of the charge bunch
Designing of a Quadrupole Paul Ion Trap
Kiyani, Abouzar; Abdollahzadeh, M.; Sadat Kiai, S. M.; Zirak, A. R.
2011-08-01
The ion motion equation in a Paul ion trap known as Mathieu differential equation has been solved for the first time by using Runge-Kutta methods with 4th, 6th, and 8th orders. The first stability regions in az - qz plane and the corresponding qmax values were determined and compared. Also, the first stability regions of , , , ions in the Vdc - Vac plane were drown, and the threshold voltages for the ion separation was investigated.
Ultrafast state detection and 2D ion crystals in a Paul trap
Ip, Michael; Ransford, Anthony; Campbell, Wesley
2016-05-01
Projective readout of quantum information stored in atomic qubits typically uses state-dependent CW laser-induced fluorescence. This method requires an often sophisticated imaging system to spatially filter out the background CW laser light. We present an alternative approach that instead uses simple pulse sequences from a mode-locked laser to affect the same state-dependent excitations in less than 1 ns. The resulting atomic fluorescence occurs in the dark, allowing the placement of non-imaging detectors right next to the atom to improve the qubit state detection efficiency and speed. We also study 2D Coulomb crystals of atomic ions in an oblate Paul trap. We find that crystals with hundreds of ions can be held in the trap, potentially offering an alternative to the use of Penning traps for the quantum simulation of 2D lattice spin models. We discuss the classical physics of these crystals and the metastable states that are supported in 2D. This work is supported by the US Army Research Office.
The β-decay Paul trap: A radiofrequency-quadrupole ion trap for precision β-decay studies
International Nuclear Information System (INIS)
Scielzo, N.D.; Li, G.; Sternberg, M.G.; Savard, G.; Bertone, P.F.; Buchinger, F.; Caldwell, S.; Clark, J.A.; Crawford, J.; Deibel, C.M.; Fallis, J.; Greene, J.P.
2012-01-01
The β-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision β-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following β decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of β-decay angular correlations in the decay of 8 Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup α particles. Many other β-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.
The {beta}-decay Paul trap: A radiofrequency-quadrupole ion trap for precision {beta}-decay studies
Energy Technology Data Exchange (ETDEWEB)
Scielzo, N.D., E-mail: scielzo1@llnl.gov [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Li, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Sternberg, M.G.; Savard, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Bertone, P.F. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Buchinger, F. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Caldwell, S. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Clark, J.A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Crawford, J. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Deibel, C.M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824 (United States); Fallis, J. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); Greene, J.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); and others
2012-07-21
The {beta}-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision {beta}-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following {beta} decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of {beta}-decay angular correlations in the decay of {sup 8}Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup {alpha} particles. Many other {beta}-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.
McAneny, M.; Freericks, J. K.
2014-11-01
The Coulomb repulsion between ions in a linear Paul trap gives rise to anharmonic terms in the potential energy when expanded about the equilibrium positions. We examine the effect of these anharmonic terms on the accuracy of a quantum simulator made from trapped ions. To be concrete, we consider a linear chain of Yb171+ ions stabilized close to the zigzag transition. We find that for typical experimental temperatures, frequencies change by no more than a factor of 0.01 % due to the anharmonic couplings. Furthermore, shifts in the effective spin-spin interactions (driven by a spin-dependent optical dipole force) are also, in general, less than 0.01 % for detunings to the blue of the transverse center-of-mass frequency. However, detuning the spin interactions near other frequencies can lead to non-negligible anharmonic contributions to the effective spin-spin interactions. We also examine an odd behavior exhibited by the harmonic spin-spin interactions for a range of intermediate detunings, where nearest-neighbor spins with a larger spatial separation on the ion chain interact more strongly than nearest neighbors with a smaller spatial separation.
Measurements of β - ν angular correlations using a transparent Paul trap
International Nuclear Information System (INIS)
Ban, G.; Delahaye, P.; Le Brun, Ch.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Szerypo, J.; Tamain, B.
1999-06-01
The potentiality to search for physics beyond the Standard Model by means of precision measurements of β - ν angular correlations in nuclear β-decay is discussed. The possibility to reveal unexpected time reversal invariant tensor type contributions is investigated and the pure Gamow-Teller decay of 6 He is considered as a possible candidate. A new experimental method is proposed which is based on the use of a transparent Paul trap surrounded by detectors to directly record β-ion coincidences in an event-by-event mode. The experiment requires intense beams of radioactive nuclei like those which will become available at the Low Energy Facility near SPIRAL at GANIL. Such beams should preferably be efficiently cooled and bunched prior to their injection into the Paul trap. Estimates of the transmission figure required for the cooling and bunching system and of the measuring time to achieve a first step are presented. (author)
Measurement of Secular Motion Frequency in Miniature Paul Trap to Ascertain the Stability Parameters
International Nuclear Information System (INIS)
Bin, Guo; Hua, Guan; Qu, Liu; Yao, Huang; Xue-Ren, Huang; Ke-Lin, Gao
2010-01-01
40 Ca + ions are trapped and laser cooled in a miniature Paul trap. The secular motion was observed by the radio-frequency resonance of the ion cloud and Zeeman profile sidebands of a single ion experimentally. The trap stability parameters a and q are determined with an uncertainty under 1 % by the secular motion frequency measurement. The trap efficiency is 0.75. A practicable suggestion is given for the benefits of a new trap design. (atomic and molecular physics)
Energy Technology Data Exchange (ETDEWEB)
Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.; Wang, Hua [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Koppell, Stewart [University of Texas at Austin, Austin, Texas 78712 (United States); Talley, Matthew [Brigham Young University, Provo, Utah 84602 (United States)
2013-05-15
Transverse dipole and quadrupole modes have been excited in a one-component cesium ion plasma trapped in the Paul Trap Simulator Experiment (PTSX) in order to characterize their properties and understand the effect of their excitation on equivalent long-distance beam propagation. The PTSX device is a compact laboratory Paul trap that simulates the transverse dynamics of a long, intense charge bunch propagating through an alternating-gradient transport system by putting the physicist in the beam's frame of reference. A pair of arbitrary function generators was used to apply trapping voltage waveform perturbations with a range of frequencies and, by changing which electrodes were driven with the perturbation, with either a dipole or quadrupole spatial structure. The results presented in this paper explore the dependence of the perturbation voltage's effect on the perturbation duration and amplitude. Perturbations were also applied that simulate the effect of random lattice errors that exist in an accelerator with quadrupole magnets that are misaligned or have variance in their field strength. The experimental results quantify the growth in the equivalent transverse beam emittance that occurs due to the applied noise and demonstrate that the random lattice errors interact with the trapped plasma through the plasma's internal collective modes. Coherent periodic perturbations were applied to simulate the effects of magnet errors in circular machines such as storage rings. The trapped one component plasma is strongly affected when the perturbation frequency is commensurate with a plasma mode frequency. The experimental results, which help to understand the physics of quiescent intense beam propagation over large distances, are compared with analytic models.
Paul Ion Trap as a Diagnostic for Plasma Focus
Sadat Kiai, S. M.; Adlparvar, S.; Zirak, A.; Alhooie, Samira; Elahi, M.; Sheibani, S.; Safarien, A.; Farhangi, S.; Dabirzadeh, A. A.; Khalaj, M. M.; Mahlooji, M. S.; KaKaei, S.; Talaei, A.; Kashani, A.; Tajik Ahmadi, H.; Zahedi, F.
2010-02-01
The plasma discharge contamination by high and low Z Impurities affect the rate of nuclear fusion reaction products, specially when light particles have to be confined. These impurities should be analyzed and can be fairly controlled. This paper reports on the development of a Paul ion trap with ion sources by impact electron ionization as a diagnostic for the 10 kJ Iranian sunshine plasma focus device. Preliminary results of the residual gas are analyzed and presented.
The LPCTrap facility for in-trap decay experiments
International Nuclear Information System (INIS)
Rodriguez, D.; Ban, G.; Durand, D.; Duval, F.; Flechard, X.; Herbane, M.; Lienard, E.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Thomas, J.-C.
2007-01-01
The LPCTrap facility is coupled to the low-energy beam line LIRAT of the SPIRAL source at GANIL (France). The facility comprises an RFQ trap for beam preparation and a transparent Paul trap for in-trap decay studies. The system has been tested for several ion species. The Paul trap has been fully characterized for 6 Li + and 23 Na + ions. This characterization together with GEANT4 simulations of the in-trap decay setup (Paul trap and detection system) has permitted to predict the effect of the size of the ion cloud on the decay study of 6 He + .
Preliminary Tests of a Paul ion Trap as an Ion Source
Sadat Kiai, S. M.; Zirak, A. R.; Elahi, M.; Adlparvar, S.; Mortazavi, B. N.; Safarien, A.; Farhangi, S.; Sheibani, S.; Alhooie, S.; Khalaj, M. M. A.; Dabirzadeh, A. A.; Ruzbehani, M.; Zahedi, F.
2010-10-01
The paper reports on the design and construction of a Paul ion trap as an ion source by using an impact electron ionization technique. Ions are produced in the trap and confined for the specific time which is then extracted and detected by a Faraday cup. Especial electronic configurations are employed between the end caps, ring electrodes, electron gun and a negative voltage for the detector. This configuration allows a constant low level of pure ion source between the pulsed confined ion sources. The present experimental results are based on the production and confinement of Argon ions with good stability and repeatability, but in principle, the technique can be used for various Argon like ions.
A very large Paul trap system for in-line capture of high-energy DC radioactive ion beams
International Nuclear Information System (INIS)
Dezfuli, A.M. Ghalambor; Moore, R.B.; Varfalvy, P.; Schwarz, S.
2002-01-01
A very large Paul trap (VLPTRAP) has built to test in-flight collection of DC ion beams. An iterative design process led to a Paul trap that was basically a cylindrical electrode of internal diameter 120 mm with two symmetrically placed coaxial end electrodes that approximated hyperboloids of revolution separated by 106 mm. The trap was operated at up to 20 kV pp at 1 MHz on the ring cylindrical electrode relative to the end electrodes with buffer gas pressures up to 40 mPa. Ions were delivered to the trap from a 60 keV + Cs ion gun and electrostatically decelerated to about 100 eV for entrance. After a cooling time of the order of 1 ms, the ions were extracted by biasing the end electrodes. Beam pulses of less than 1 s could be extracted, at repetition rates down to 1 Hz. An overall bunching efficiency of about 0.4% was obtained, resulting from a collection efficiency of 2% and an extraction efficiency of 20%. The trap could hold up to 10 7 ions at a temperature of 1000 K
Energy Technology Data Exchange (ETDEWEB)
Kaufmann, Delia
2012-02-03
Strings of laser cooled ions stored in microstructured Paul traps (microtraps) have promising potential for quantum information science. They provide a system which can be screened from a decohering environment, accurately prepared, manipulated and state selectively detected with efficiency close to unity. Magnetic field gradients allow for addressing trapped ions in frequency space. Furthermore, coupling of the ions' motional and spin states and long range spin-spin coupling of the ions' internal states are induced by such a gradient. This method is called Magnetic Gradient Induced Coupling, MAGIC. In this thesis, the design, construction and first characterization of a novel microtrap with an integrated solenoid is reported. The solenoid is designed to create a high magnetic field gradient per dissipated heat. The microtrap consists of three layers stacked onto each other. The outer layers provide a trapping potential, while the inner layer creates the switchable magnetic field gradient. Another specialty of this trap is the 33 pairs of DC-electrodes, allowing to move the ions along the trap axis and to adjust the range and the strength of the ions' spin-spin interactions. The microtrap is fixed on top of a ceramic block that provides the necessary electrical connections via thick film printed wires, a technique adopted in the context of microtraps for the first time, and in addition acts as a vacuum interface. The volume of the vacuum chamber is quite small, allowing for pressures in the low 10{sup -11} mbar range. In this microtrap, {sup 172}Yb{sup +}-ions are trapped, cooled and shuttled over a distance of about 2 mm. Trapped ions are used as magnetic field gradient probes, with a relative magnetic field precision of {delta}B/B{sub 0}=7.10{sup -6}. The addressing of two ions with the MAGIC method in the solenoid's magnetic field gradient is demonstrated.
Measurement Of The β-ν Correlation In 6He Using A Transparent Paul Trap
International Nuclear Information System (INIS)
Lienard, E.; Ban, G.; Darius, G.; Durand, D.; Flechard, X.; Herbane, M.; Labalme, M.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.
2006-01-01
The angular correlation between the electron and the neutrino in nuclear β-decay constitutes a sensitive observable to search for the existence of exotic couplings in the weak interaction. In this contribution, we describe the progress of the LPCTrap experiment, devoted to measure the β-ν angular correlation in the pure Gamow-Teller (GT) decay of 6He using a transparent Paul trap. We present a first coincidence spectrum, obtained during the commissioning run, which is the first β-recoil coincidence measurement obtained from any ion trap
Positioning of the rf potential minimum line of a linear Paul trap with micrometer precision
DEFF Research Database (Denmark)
Herskind, Peter Fønss; Dantan, Aurélien; Albert, Magnus
2009-01-01
We demonstrate a general technique to achieve a precise radial displacement of the nodal line of the radiofrequency (rf) field in a linear Paul trap. The technique relies on the selective adjustment of the load capacitance of the trap electrodes, achieved through the addition of capacitors...... to the basic resonant rf circuit used to drive the trap. Displacements of up to ~100 µm with micrometer precision are measured using a combination of fluorescence images of ion Coulomb crystals and coherent coupling of such crystals to a mode of an optical cavity. The displacements are made without measurable...
Paul Trapping of Radioactive 6He+ Ions and Direct Observation of Their β Decay
International Nuclear Information System (INIS)
Flechard, X.; Lienard, E.; Mery, A.; Rodriguez, D.; Ban, G.; Durand, D.; Duval, F.; Herbane, M.; Labalme, M.; Mauger, F.; Naviliat-Cuncic, O.; Velten, Ph.; Thomas, J. C.
2008-01-01
We demonstrate that abundant quantities of short-lived β unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6 He + (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then decelerated, cooled, and bunched by means of the buffer gas cooling technique. More than 10 8 ions have been stored over a measuring period of six days, and about 10 5 decay coincidences between the beta particles and the 6 Li ++ recoiling ions have been recorded. The technique can be extended to other short-lived species, opening new possibilities for trap assisted decay experiments
Experimental investigation of the stability diagram for Paul traps in the case of praseodymium ions
International Nuclear Information System (INIS)
Koczorowski, W.; Szawiola, G.; Walaszyk, A.; Buczek, A.; Stefanska, D.; Stachowska, E.
2006-01-01
The present paper describes an investigation of non-linear resonances of praseodymium ion clouds stored in a Paul trap as a function of the storage parameters. These have been observed in traps with different ring electrode diameters. In these different traps the resonances occur for different values of the operating parameters. Discrepancies with the approximation model for one ion have been found. The intensity of the fluorescence signal and the Doppler half width have been recorded as a function of one of the storage parameters: q. We use our results to optimize the fluorescence signal of the stored ions, which is especially useful in the case of the double-resonance method.
The ion circus: A novel circular Paul trap to resolve isobaric contamination
Energy Technology Data Exchange (ETDEWEB)
Ramirez, E. Minaya [CSNSM-IN2P3/CNRS, Bat. 108, Universite de Paris Sud, 91405 Orsay (France)], E-mail: minaya@csnsm.in2p3.fr; Cabaret, S.; Lunney, D. [CSNSM-IN2P3/CNRS, Bat. 108, Universite de Paris Sud, 91405 Orsay (France)
2008-10-15
The ion circus is a miniature storage ring formed by a segmented radiofrequency mass filter bent into a circle. The primary goal of this unique device is to perform high-resolution mass separation with small transmission loss since the resolving power is increased while the orbiting ions cool in the ring. Contrary to its linear brother, this circular Paul trap is designed to cool and mass separate the ions over a much longer flight path, thus requiring lower buffer gas pressure. Ions can be accumulated in the ring and extracted either in tangential or perpendicular directions. This way, the trap also serves as a versatile beam distribution device. Design principles are presented and the prototype instrument, under test in Orsay, is described.
Observation of a structural transition for coulomb crystals in a linear Paul trap
DEFF Research Database (Denmark)
Kjærgaard, N.; Drewsen, M.
2003-01-01
A structural transition for laser cooled ion Coulomb crystals in a linear Paul trap just above the stability limit of parametrically resonant excitation of bulk plasma modes has been observed. In contrast to the usual spheroidal shell structures present below the stability limit, the ions arrange...... in a "string-of-disks" configuration. The spheroidal envelopes of the string-of-disks structures are in agreement with results from cold fluid theory usually valid for ion Coulomb crystals if the ion systems are assumed to be rotating collectively....
Observation of a structural transition for Coulomb crystals in a linear Paul trap
International Nuclear Information System (INIS)
Kjaergaard, Niels; Drewsen, Michael
2003-01-01
A structural transition for laser cooled ion Coulomb crystals in a linear Paul trap just above the stability limit of parametrically resonant excitation of bulk plasma modes has been observed. In contrast to the usual spheroidal shell structures present below the stability limit, the ions arrange in a 'string-of-disks' configuration. The spheroidal envelopes of the string-of-disks structures are in agreement with results from cold fluid theory usually valid for ion Coulomb crystals if the ion systems are assumed to be rotating collectively
Energy Technology Data Exchange (ETDEWEB)
Hirsh, T. Y.; Perez Galvan, A.; Burkey, M.; Aprahamian, A.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Gallant, A.; Heckmaier, E.; Levand, A. F.; Savard, G.
2018-04-01
This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy.
International Nuclear Information System (INIS)
Gilson, Erik P.; Davidson, Ronald C.; Dorf, Mikhail; Efthimion, Philip C.; Majeski, Richard; Chung, Moses; Gutierrez, Michael S.; Kabcenell, Aaron N.
2010-01-01
The Paul Trap Simulator Experiment (PTSX) is a compact laboratory experiment that places the physicist in the frame-of-reference of a long, charged-particle bunch coasting through a kilometers-long magnetic alternating-gradient (AG) transport system. The transverse dynamics of particles in both systems are described by the same set of equations, including nonlinear space-charge effects. The time-dependent voltages applied to the PTSX quadrupole electrodes in the laboratory frame are equivalent to the spatially periodic magnetic fields applied in the AG system. The transverse emittance of the charge bunch, which is a measure of the area in the transverse phase space that the beam distribution occupies, is an important metric of beam quality. Maintaining low emittance is an important goal when defining AG system tolerances and when designing AG systems to perform beam manipulations such as transverse beam compression. Results are reviewed from experiments in which white noise and colored noise of various amplitudes and durations have been applied to the PTSX electrodes. This noise is observed to drive continuous emittance growth and increase in root-mean-square beam radius over hundreds of lattice periods. Additional results are reviewed from experiments that determine the conditions necessary to adiabatically reduce the charge bunch's transverse size and simultaneously maintain high beam quality. During adiabatic transitions, there is no change in the transverse emittance. The transverse compression can be achieved either by a gradual change in the PTSX voltage waveform amplitude or frequency. Results are presented from experiments in which low emittance is achieved by using focusing-off-defocusing-off waveforms.
Precise positioning of an ion in an integrated Paul trap-cavity system using radiofrequency signals
Kassa, Ezra; Takahashi, Hiroki; Christoforou, Costas; Keller, Matthias
2018-03-01
We report a novel miniature Paul ion trap design with an integrated optical fibre cavity which can serve as a building block for a fibre-linked quantum network. In such cavity quantum electrodynamic set-ups, the optimal coupling of the ions to the cavity mode is of vital importance and this is achieved by moving the ion relative to the cavity mode. The trap presented herein features an endcap-style design complemented with extra electrodes on which additional radiofrequency voltages are applied to fully control the pseudopotential minimum in three dimensions. This method lifts the need to use three-dimensional translation stages for moving the fibre cavity with respect to the ion and achieves high integrability, mechanical rigidity and scalability. Not based on modifying the capacitive load of the trap, this method leads to precise control of the pseudopotential minimum allowing the ion to be moved with precisions limited only by the ion's position spread. We demonstrate this by coupling the ion to the fibre cavity and probing the cavity mode profile.
Energy Technology Data Exchange (ETDEWEB)
Delahaye, P
2002-03-01
The subject of this thesis is the preparation of a measurement of the {beta} - {nu} angular correlation coefficient, in {sup 6}He nuclear {beta} - decay, using a Paul trap. Its principle consists in studying the decay of radioactive ions trapped in a small volume, practically at rest in the center of a transparent electric trap. The trajectories of the particles emitted in the decay are weakly disturbed. The detection in coincidence of the electron and the recoil ion in each decay allows the measurement of 3 observables: the energies of the particles and their relative angle. The {beta} - {nu} angular correlation parameter deduced from the coincidence spectrum is sensitive to the existence of exotic interactions excluded by the V - A theory of the weak interactions. In the case of {sup 6}He decay a deviation observed on the predicted value would imply the existence of tensor type interactions, which might be due to the exchange of leptoquarks. These are gauge bosons present in many extensions of the Standard Model. The work presented here concerns the tests of a transparent Paul trap. The performance of the trap has been tested with ions created in a laser plasma source (Mo{sup +}, Fe{sup +}, Al{sup +}), and also with ions delivered by an ionization source ({sup 4}He{sup +} ions). These experiments were carried out in parallel with their simulations which required the development of a computer code of the electrical potential in various geometries, and of a code of ions transport in the associated fields. These simulations showed a good agreement with the experiment. A Monte Carlo simulation of the experimental setup, for the {beta} - {nu} angular correlation measurement, was then carried out. The distortions of the spectra associated with the varying electric fields in the vicinity of the trap and with the ion cloud size were estimated for various geometries. The statistical needs for the experiment were evaluated in order to reach the required precision. (author)
Digital quantum simulation, Schrödinger cat state spectroscopy and setting up a linear ion trap
International Nuclear Information System (INIS)
Hempel, C.
2014-01-01
This PhD thesis reports on two experiments in the field of quantum information processing using trapped calcium ions. In addition, the text covers the setup and characterization of a new linear Paul trap accompanied by a novel implementation of single-ion addressing using an acousto-optic deflector. The first of the two experiments is concerned with the proof-of-principle implementation of digital quantum simulations using up to 6 ions and 100 gate operations. It investigates the scaling behavior of simulations of elementary models of magnetism in terms of the number of involved spins and the complexity of their mutual interactions. The second experiment introduces the application of a Schroedinger cat state in the indirect detection of photon scattering events on a broad electronic transition. The method is shown to have a sensitivity down to the single photon level in a proof-of-principle demonstration using a mixed-isotope crystal of 40Ca+ and 44Ca+. A brief outlook towards future experiments and extensions of the experimental setup concludes the manuscript.(author) [de
Optimization and simulation of MEMS rectilinear ion trap
Directory of Open Access Journals (Sweden)
Huang Gang
2015-04-01
Full Text Available In this paper, the design of a MEMS rectilinear ion trap was optimized under simulated conditions. The size range of the MEMS rectilinear ion trap’s electrodes studied in this paper is measured at micron scale. SIMION software was used to simulate the MEMS rectilinear ion trap with different sizes and different radio-frequency signals. The ion-trapping efficiencies of the ion trap under these different simulation conditions were obtained. The ion-trapping efficiencies were compared to determine the performance of the MEMS rectilinear ion trap in different conditions and to find the optimum conditions. The simulation results show that for the ion trap at micron scale or smaller, the optimized length–width ratio was 0.8, and a higher frequency of radio-frequency signal is necessary to obtain a higher ion-trapping efficiency. These results have a guiding role in the process of developing MEMS rectilinear ion traps, and great application prospects in the research fields of the MEMS rectilinear ion trap and the MEMS mass spectrometer.
Energy Technology Data Exchange (ETDEWEB)
Mihalcea, Bogdan M., E-mail: bogdan.mihalcea@inflpr.ro; Vişan, Gina T.; Ganciu, Mihai [National Institute for Laser, Plasma and Radiation Physics (INFLPR), Atomiştilor Str. Nr. 409, 077125 Măgurele, Ilfov (Romania); Giurgiu, Liviu C. [University of Bucharest, Faculty of Physics, Atomistilor Str. Nr. 405, 077125 Măgurele (Romania); Stan, Cristina [Department of Physics, Politehnica University, 313 Splaiul Independenţei, RO-060042 Bucharest (Romania); Filinov, Vladimir; Lapitsky, Dmitry, E-mail: dmitrucho@yandex.ru; Deputatova, Lidiya; Syrovatka, Roman [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya Str. 13, Bd. 2, 125412 Moscow (Russian Federation)
2016-03-21
Trapping of microparticles and aerosols is of great interest for physics and chemistry. We report microparticle trapping in case of multipole linear Paul trap geometries, operating under standard ambient temperature and pressure conditions. An 8- and 12-electrode linear trap geometries have been designed and tested with an aim to achieve trapping for larger number of particles and to study microparticle dynamical stability in electrodynamic fields. We report emergence of planar and volume ordered structures of microparticles, depending on the a.c. trapping frequency and particle specific charge ratio. The electric potential within the trap is mapped using the electrolytic tank method. Particle dynamics is simulated using a stochastic Langevin equation. We emphasize extended regions of stable trapping with respect to quadrupole traps, as well as good agreement between experiment and numerical simulations.
International Nuclear Information System (INIS)
Mihalcea, Bogdan M.; Vişan, Gina T.; Ganciu, Mihai; Giurgiu, Liviu C.; Stan, Cristina; Filinov, Vladimir; Lapitsky, Dmitry; Deputatova, Lidiya; Syrovatka, Roman
2016-01-01
Trapping of microparticles and aerosols is of great interest for physics and chemistry. We report microparticle trapping in case of multipole linear Paul trap geometries, operating under standard ambient temperature and pressure conditions. An 8- and 12-electrode linear trap geometries have been designed and tested with an aim to achieve trapping for larger number of particles and to study microparticle dynamical stability in electrodynamic fields. We report emergence of planar and volume ordered structures of microparticles, depending on the a.c. trapping frequency and particle specific charge ratio. The electric potential within the trap is mapped using the electrolytic tank method. Particle dynamics is simulated using a stochastic Langevin equation. We emphasize extended regions of stable trapping with respect to quadrupole traps, as well as good agreement between experiment and numerical simulations.
Energy Technology Data Exchange (ETDEWEB)
Mery, A
2007-07-15
The central topic of this work is the study of the properties and the implementation of a Paul trap used for the measurement of the beta-neutrino angular correlation parameter in the decay of {sup 6}He. This coefficient provides a signature of the nature of the interactions involved in the weak interaction. The value of this coefficient can be deduced from the kinematical distribution of the decay events. An electromagnetic trap is used for the trapping of {sup 6}He{sup +} ions in a small volume. This trap has an open geometry that enables the detection in coincidence of the electron and the recoil ion emitted in the beta decay. A dedicated detection set up is used for the measurement of the electron energy, the ion time of flight and the position of the two particles for each event. A general description of the LPCTrap facility and of its performances is presented and shows that this set up is able to fulfill the proposed measurement. Especially, a comparison is made between the characteristics of the ion cloud obtained from Monte Carlo simulations and the experimental measurements with a good agreement. More than 100 000 coincident events have been recorded during the first experiment. A preliminary analysis of these results is shown. It includes a description of the different observables as well as a comparison between the experimental time of flight spectrum and the simulated spectrum. These data will allow a measurement of the angular correlation parameter with a statistical error smaller than 2 %. (author)
International Nuclear Information System (INIS)
Lienard, E.; Ban, G.; Blieck, J.; Durand, D.; Duval, F.; Flechard, X.; Herbane, M.; Labalme, M.; Lemiere, Y.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.; Thomas, J. C.
2006-01-01
We report on the status of the LPCTrap experiment, devoted to measure the β-ν angular correlation in the pure Gamow-Teller decay of 6 He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The 6 He ions are confined in a novel transparent Paul trap. The β particles and the recoil ions are detected in coincidence to deduce the angular correlation parameter. The commissioning run performed in 2005 has given the proof of principle of this experiment. Up to 10 5 coincidences were recorded during a second run in 2006.
Modes of oscillation in radiofrequency Paul traps
DEFF Research Database (Denmark)
Landa, H.; Reznik, B.; Drewsen, M.
2012-01-01
We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general threedimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We analytically derive the micromotion amplitude of the ions...
Experimental simulations of beam propagation over large distances in a compact linear Paul trapa)
Gilson, Erik P.; Chung, Moses; Davidson, Ronald C.; Dorf, Mikhail; Efthimion, Philip C.; Majeski, Richard
2006-05-01
The Paul Trap Simulator Experiment (PTSX) is a compact laboratory experiment that places the physicist in the frame of reference of a long, charged-particle bunch coasting through a kilometers-long magnetic alternating-gradient (AG) transport system. The transverse dynamics of particles in both systems are described by similar equations, including nonlinear space-charge effects. The time-dependent voltages applied to the PTSX quadrupole electrodes are equivalent to the axially oscillating magnetic fields applied in the AG system. Experiments concerning the quiescent propagation of intense beams over large distances can then be performed in a compact and flexible facility. An understanding and characterization of the conditions required for quiescent beam transport, minimum halo particle generation, and precise beam compression and manipulation techniques, are essential, as accelerators and transport systems demand that ever-increasing amounts of space charge be transported. Application areas include ion-beam-driven high energy density physics, high energy and nuclear physics accelerator systems, etc. One-component cesium plasmas have been trapped in PTSX that correspond to normalized beam intensities, ŝ=ωp2(0)/2ωq2, up to 80% of the space-charge limit where self-electric forces balance the applied focusing force. Here, ωp(0)=[nb(0)eb2/mbɛ0]1/2 is the on-axis plasma frequency, and ωq is the smooth-focusing frequency associated with the applied focusing field. Plasmas in PTSX with values of ŝ that are 20% of the limit have been trapped for times corresponding to equivalent beam propagation over 10km. Results are presented for experiments in which the amplitude of the quadrupole focusing lattice is modified as a function of time. It is found that instantaneous changes in lattice amplitude can be detrimental to transverse confinement of the charge bunch.
2011-12-01
variations of ion traps, including (1) the cylindrically symmetric 3D ring trap; (2) the linear trap with a combination of cavity QED; (#) the symmetric...concepts of quantum information. The major demonstration has been the test of a Bell inequality as demonstrated by Rowe et al. [50] and a decoherence...famous physics experiment [62]. Wolfgang Paul demonstrated a similar apparatus during his Nobel Prize speech [63]. This device is hyperbolic- parabolic
Characterization of ion Coulomb crystals in a linear Paul trap
International Nuclear Information System (INIS)
Okada, K.; Takayanagi, T.; Wada, M.; Ohtani, S.; Schuessler, H. A.
2010-01-01
We describe a simple and fast method for simulating observed images of ion Coulomb crystals. In doing so, cold elastic collisions between Coulomb crystals and virtual very light atoms are implemented in a molecular dynamics (MD) simulation code. Such an approach reproduces the observed images of Coulomb crystals by obtaining density plots of the statistics of existence of each ion. The simple method has the advantage of short computing time in comparison with previous calculation methods. As a demonstration of the simulation, the formation of a planar Coulomb crystal with a small number of ions has been investigated in detail in a linear ion trap both experimentally and by simulation. However, also large Coulomb crystals including up to 1400 ions have been photographed and simulated to extract the secular temperature and the number of ions. For medium-sized crystals, a comparison between experiments and calculations has been performed. Moreover, an MD simulation of the sympathetic cooling of small molecular ions was performed in order to test the possibility of extracting the temperature and the number of refrigerated molecular ions from crystal images of laser-cooled ions. Such information is basic to studying ultracold ion-molecule reactions using ion Coulomb crystals including sympathetically cooled molecular ions.
International Nuclear Information System (INIS)
Leuthner, Heiko
2011-01-01
Paul-traps are a widely used tool in scientific research and play an important role in atomic physics and mass spectrometry. (1) From the earth-alkaline ions only spectroscopic data of Ra + are lacking. Those are important for the test of theoretical models and for a future atomic parity violation experiment. The first part of this work describes the setting up of a Paul-trap based Laser-experiment for measuring the lifetime of the 6D 3/2 state of 226 Ra + . Basic tests with 138 Ba + ions are presented. (2) Damping and space charge effects on resonances in the stability region strongly affect the use of Paul-traps in mass spectrometry and analysis of reaction products. The second part of this work presents detailed investigations on the storage of big, buffer-gas-cooled ion clouds in two different Paul-trap experiments; the first of them uses 138 Ba + ions detected continuously by electronic and optical detection systems, the second one uses N 2 + molecular ions and an automated destructive time-of-flight-detection method. A high precision measurement with N 2 + of the first stability region of the trap not only gives the possibility of direct comparison of experimental and theoretical resonances but also provides absolute ion numbers over the whole region for the first time. Unlike previous measurements, the investigations on nonlinear resonances where done on the superimposed stability regions of 4 simultaneously stored ion species. The nonlinear resonances were studied by varying buffer gas pressure and ion number and showed collective resonances without external excitation. By varying the buffer gas pressure the spatial distribution of a Ba + -ion cloud was investigated as well as the change of the optimal storing parameters using N 2 + -ions. Optimum Pressures for catching and trapping of ions turned out to be unequal. Shape and position of externally excited collective and individual resonances were studied under variation of ion number, buffer-gas pressure
Electron spin resonance from NV centers in diamonds levitating in an ion trap
International Nuclear Information System (INIS)
Delord, T; Nicolas, L; Schwab, L; Hétet, G
2017-01-01
We report observations of the electron spin resonance (ESR) of nitrogen vacancy centers in diamonds that are levitating in an ion trap. Using a needle Paul trap operating under ambient conditions, we demonstrate efficient microwave driving of the electronic spin and show that the spin properties of deposited diamond particles measured by the ESR are retained in the Paul trap. We also exploit the ESR signal to show angle stability of single trapped mono-crystals, a necessary step towards spin-controlled levitating macroscopic objects. (paper)
Kluge, Heinz-Jürgen
2004-01-01
Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.
International Nuclear Information System (INIS)
Kluge, H.-J.; Blaum, K.
2004-01-01
Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning
Random-walk simulation of diffusion-controlled processes among static traps
International Nuclear Information System (INIS)
Lee, S.B.; Kim, I.C.; Miller, C.A.; Torquato, S.; Department of Mechanical and Aerospace Engineering and Department of Chemical Engineering, North Carolina State University, Raleigh, North Carolina 27695-7910)
1989-01-01
We present computer-simulation results for the trapping rate (rate constant) k associated with diffusion-controlled reactions among identical, static spherical traps distributed with an arbitrary degree of impenetrability using a Pearson random-walk algorithm. We specifically consider the penetrable-concentric-shell model in which each trap of diameter σ is composed of a mutually impenetrable core of diameter λσ, encompassed by a perfectly penetrable shell of thickness (1-λ)σ/2: λ=0 corresponding to randomly centered or ''fully penetrable'' traps and λ=1 corresponding to totally impenetrable traps. Trapping rates are calculated accurately from the random-walk algorithm at the extreme limits of λ (λ=0 and 1) and at an intermediate value (λ=0.8), for a wide range of trap densities. Our simulation procedure has a relatively fast execution time. It is found that k increases with increasing impenetrability at fixed trap concentration. These ''exact'' data are compared with previous theories for the trapping rate. Although a good approximate theory exists for the fully-penetrable-trap case, there are no currently available theories that can provide good estimates of the trapping rate for a moderate to high density of traps with nonzero hard cores (λ>0)
Active stabilization of ion trap radiofrequency potentials
Energy Technology Data Exchange (ETDEWEB)
Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C. [Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742 (United States)
2016-05-15
We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.
Winter School on Physics with Trapped Charged Particles - Abstracts and slides
International Nuclear Information System (INIS)
Pedersen, T.S.; Thompson, R.C.; Madsen, N.; Champenois, C.; Anderegg, F.; Fajans, J.; Knoop, M.; Scott Hangst, J.; Hilico, L.; Ulmer, S.; Blaum, K.; Drewsen, M.; Roos, C.; Schmidt, P.
2016-01-01
This winter school covered various topics of the physics of trapped charged particles. Lectures covered basic trap physics and recent developments in Penning traps, Paul traps..., collective behavior and non-neutral plasmas, as well as applications for fundamental physics, laser cooling, precision spectroscopy and quantum information. This document gathers a booklet of abstracts and the available slides of the presentations
Quantum information processing with trapped ions
International Nuclear Information System (INIS)
Haeffner, H.; Haensel, W.; Rapol, U.; Koerber, T.; Benhelm, J.; Riebe, M.; Chek-al-Kar, D.; Schmidt-Kaler, F.; Becher, C.; Roos, C.; Blatt, R.
2005-01-01
Single Ca + ions and crystals of Ca + ions are confined in a linear Paul trap and are investigated for quantum information processing. Here we report on recent experimental advancements towards a quantum computer with such a system. Laser-cooled trapped ions are ideally suited systems for the investigation and implementation of quantum information processing as one can gain almost complete control over their internal and external degrees of freedom. The combination of a Paul type ion trap with laser cooling leads to unique properties of trapped cold ions, such as control of the motional state down to the zero-point of the trapping potential, a high degree of isolation from the environment and thus a very long time available for manipulations and interactions at the quantum level. The very same properties make single trapped atoms and ions well suited for storing quantum information in long lived internal states, e.g. by encoding a quantum bit (qubit) of information within the coherent superposition of the S 1/2 ground state and the metastable D 5/2 excited state of Ca + . Recently we have achieved the implementation of simple algorithms with up to 3 qubits on an ion-trap quantum computer. We will report on methods to implement single qubit rotations, the realization of a two-qubit universal quantum gate (Cirac-Zoller CNOT-gate), the deterministic generation of multi-particle entangled states (GHZ- and W-states), their full tomographic reconstruction, the realization of deterministic quantum teleportation, its quantum process tomography and the encoding of quantum information in decoherence-free subspaces with coherence times exceeding 20 seconds. (author)
Energy Technology Data Exchange (ETDEWEB)
Velten, Ph., E-mail: velten@lpccaen.in2p3.fr; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.; Thomas, J. C. [Universite de Caen, LPC Caen, ENSICAEN (France)
2011-07-15
The LPCTrap experiment is devoted to the precise measurement of the {beta}-{nu} angular correlation parameter, a{sub {beta}{nu}}, in the pure Gamow-Teller decay of {sup 6}He{sup +}. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined in a transparent Paul trap installed at LIRAT, the low energy beam line of the SPIRAL facility. The {beta}-{nu} correlation is studied by measuring the time of flight of the recoil ions detected in coincidence with the {beta} particles. During the last experiment, a total of 4 Multiplication-Sign 10{sup 6} coincidence events have been recorded which would enable to determine the coefficient with a statistical uncertainty of 0.5%. The status of the analysis is presented in this contribution.
Charged particle traps II applications
Werth, Günther; Major, Fouad G
2009-01-01
This, the second volume of Charged Particle Traps, is devoted to applications, complementing the first volume’s comprehensive treatment of the theory and practice of charged particle traps, their many variants and refinements. In recent years, applications of far reaching importance have emerged ranging from the ultra-precise mass determinations of elementary particles and their antiparticles and short-lived isotopes, to high-resolution Zeeman spectroscopy on multiply-charged ions, to microwave and optical spectroscopy, some involving "forbidden" transitions from metastable states of such high resolution that optical frequency standards are realized by locking lasers to them. Further the potential application of trapped ions to quantum computing is explored, based on the extraordinary quantum state coherence made possible by the particle isolation. Consideration is given to the Paul and Penning traps as potential quantum information processors.
Warburton, Bruce; Gormley, Andrew M
2015-01-01
Internationally, invasive vertebrate species pose a significant threat to biodiversity, agricultural production and human health. To manage these species a wide range of tools, including traps, are used. In New Zealand, brushtail possums (Trichosurus vulpecula), stoats (Mustela ermine), and ship rats (Rattus rattus) are invasive and there is an ongoing demand for cost-effective non-toxic methods for controlling these pests. Recently, traps with multiple-capture capability have been developed which, because they do not require regular operator-checking, are purported to be more cost-effective than traditional single-capture traps. However, when pest populations are being maintained at low densities (as is typical of orchestrated pest management programmes) it remains uncertain if it is more cost-effective to use fewer multiple-capture traps or more single-capture traps. To address this uncertainty, we used an individual-based spatially explicit modelling approach to determine the likely maximum animal-captures per trap, given stated pest densities and defined times traps are left between checks. In the simulation, single- or multiple-capture traps were spaced according to best practice pest-control guidelines. For possums with maintenance densities set at the lowest level (i.e. 0.5/ha), 98% of all simulated possums were captured with only a single capacity trap set at each site. When possum density was increased to moderate levels of 3/ha, having a capacity of three captures per trap caught 97% of all simulated possums. Results were similar for stoats, although only two potential captures per site were sufficient to capture 99% of simulated stoats. For rats, which were simulated at their typically higher densities, even a six-capture capacity per trap site only resulted in 80% kill. Depending on target species, prevailing density and extent of immigration, the most cost-effective strategy for pest control in New Zealand might be to deploy several single
Experimental quantum simulations of many-body physics with trapped ions.
Schneider, Ch; Porras, Diego; Schaetz, Tobias
2012-02-01
Direct experimental access to some of the most intriguing quantum phenomena is not granted due to the lack of precise control of the relevant parameters in their naturally intricate environment. Their simulation on conventional computers is impossible, since quantum behaviour arising with superposition states or entanglement is not efficiently translatable into the classical language. However, one could gain deeper insight into complex quantum dynamics by experimentally simulating the quantum behaviour of interest in another quantum system, where the relevant parameters and interactions can be controlled and robust effects detected sufficiently well. Systems of trapped ions provide unique control of both the internal (electronic) and external (motional) degrees of freedom. The mutual Coulomb interaction between the ions allows for large interaction strengths at comparatively large mutual ion distances enabling individual control and readout. Systems of trapped ions therefore exhibit a prominent system in several physical disciplines, for example, quantum information processing or metrology. Here, we will give an overview of different trapping techniques of ions as well as implementations for coherent manipulation of their quantum states and discuss the related theoretical basics. We then report on the experimental and theoretical progress in simulating quantum many-body physics with trapped ions and present current approaches for scaling up to more ions and more-dimensional systems.
Effect of Single-Electron Interface Trapping in Decanano MOSFETs: A 3D Atomistic Simulation Study
Asenov, Asen; Balasubramaniam, R.; Brown, A. R.; Davies, J. H.
2000-01-01
We study the effect of trapping/detrapping of a single-electron in interface states in the channel of n-type MOSFETs with decanano dimensions using 3D atomistic simulation techniques. In order to highlight the basic dependencies, the simulations are carried out initially assuming continuous doping charge, and discrete localized charge only for the trapped electron. The dependence of the random telegraph signal (RTS) amplitudes on the device dimensions and on the position of the trapped charge in the channel are studied in detail. Later, in full-scale, atomistic simulations assuming discrete charge for both randomly placed dopants and the trapped electron, we highlight the importance of current percolation and of traps with strategic position where the trapped electron blocks a dominant current path.
Gas Bubble Migration and Trapping in Porous Media: Pore-Scale Simulation
Mahabadi, Nariman; Zheng, Xianglei; Yun, Tae Sup; van Paassen, Leon; Jang, Jaewon
2018-02-01
Gas bubbles can be naturally generated or intentionally introduced in sediments. Gas bubble migration and trapping affect the rate of gas emission into the atmosphere or modify the sediment properties such as hydraulic and mechanical properties. In this study, the migration and trapping of gas bubbles are simulated using the pore-network model extracted from the 3D X-ray image of in situ sediment. Two types of bubble size distribution (mono-sized and distributed-sized cases) are used in the simulation. The spatial and statistical bubble size distribution, residual gas saturation, and hydraulic conductivity reduction due to the bubble trapping are investigated. The results show that the bubble size distribution becomes wider during the gas bubble migration due to bubble coalescence for both mono-sized and distributed-sized cases. And the trapped bubble fraction and the residual gas saturation increase as the bubble size increases. The hydraulic conductivity is reduced as a result of the gas bubble trapping. The reduction in hydraulic conductivity is apparently observed as bubble size and the number of nucleation points increase.
International Nuclear Information System (INIS)
Neidherr, D.; Blaum, K.; Block, M.; Ferrer, R.; Herfurth, F.; Ketelaer, J.; Nagy, Sz.; Weber, C.
2008-01-01
Penning traps are ideal tools to perform high-precision mass measurements. For this purpose the cyclotron frequency of the stored charged particles is measured. In case of on-line mass measurements of short-lived nuclides produced at radioactive beam facilities the ions get in general first prepared and cooled by buffer-gas collisions in a preparation trap to reduce their motional amplitudes and are then transported to a precision trap for the cyclotron frequency determination. In modern Penning trap mass spectrometers both traps are placed in the homogeneous region of one superconducting magnet to optimize the transport efficiency. Because the gas pressure inside the precision trap has to be very low in order to minimize the damping of the ion motion caused by collisions with rest gas molecules during the frequency determination, a pumping barrier is installed between both traps. To predict the pressure difference between the two traps in the region of molecular gas flow the motion of each particle can be simulated without consideration of the other particles. Thus, it is possible to calculate the transit probability through a tube of a given geometry. The results are compared with experimentally obtained pressure differences.
Analog quantum simulation of generalized Dicke models in trapped ions
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.
Trapping hydrogen atoms from a neon-gas matrix: a theoretical simulation.
Bovino, S; Zhang, P; Kharchenko, V; Dalgarno, A
2009-08-07
Hydrogen is of critical importance in atomic and molecular physics and the development of a simple and efficient technique for trapping cold and ultracold hydrogen atoms would be a significant advance. In this study we simulate a recently proposed trap-loading mechanism for trapping hydrogen atoms released from a neon matrix. Accurate ab initio quantum calculations are reported of the neon-hydrogen interaction potential and the energy- and angular-dependent elastic scattering cross sections that control the energy transfer of initially cold atoms are obtained. They are then used to construct the Boltzmann kinetic equation, describing the energy relaxation process. Numerical solutions of the Boltzmann equation predict the time evolution of the hydrogen energy distribution function. Based on the simulations we discuss the prospects of the technique.
Simulating quantum effects of cosmological expansion using a static ion trap
Menicucci, Nicolas C.; Olson, S. Jay; Milburn, Gerard J.
2010-09-01
We propose a new experimental test bed that uses ions in the collective ground state of a static trap to study the analogue of quantum-field effects in cosmological spacetimes, including the Gibbons-Hawking effect for a single detector in de Sitter spacetime, as well as the possibility of modeling inflationary structure formation and the entanglement signature of de Sitter spacetime. To date, proposals for using trapped ions in analogue gravity experiments have simulated the effect of gravity on the field modes by directly manipulating the ions' motion. In contrast, by associating laboratory time with conformal time in the simulated universe, we can encode the full effect of curvature in the modulation of the laser used to couple the ions' vibrational motion and electronic states. This model simplifies the experimental requirements for modeling the analogue of an expanding universe using trapped ions, and it enlarges the validity of the ion-trap analogy to a wide range of interesting cases.
. Cory, and J. Newcomb. 2009. Renewable Energy Project Financing: Impacts of the Financial Crisis and Schwabe Photo of Paul Schwabe Paul Schwabe Project Manager IV-Research Paul.Schwabe@nrel.gov | 303 . Cory, K. and P. Schwabe. 2009. Wind Levelized Cost of Energy: A Comparison of Technical and Financing
Nonlinear PIC simulation in a Penning trap
International Nuclear Information System (INIS)
Lapenta, G.; Delzanno, G.L.; Finn, J. M.
2002-01-01
We study the nonlinear dynamics of a Penning trap plasma, including the effect of the finite length and end curvature of the plasma column. A new cylindrical PIC code, called KANDINSKY, has been implemented by using a new interpolation scheme. The principal idea is to calculate the volume of each cell from a particle volume, in the same manner as it is done for the cell charge. With this new method, the density is conserved along streamlines and artificial sources of compressibility are avoided. The code has been validated with a reference Eulerian fluid code. We compare the dynamics of three different models: a model with compression effects, the standard Euler model and a geophysical fluid dynamics model. The results of our investigation prove that Penning traps can really be used to simulate geophysical fluids
Thermometry of levitated nanoparticles in a hybrid electro-optical trap
Aranas, E. B.; Fonseca, P. Z. G.; Barker, P. F.; Monteiro, T. S.
2017-03-01
There have been recent rapid developments in stable trapping of levitated nanoparticles in high vacuum. Cooling of nanoparticles, from phonon occupancies of 107 down to ≃ 100{--}1000 phonons, have already been achieved by several groups. Prospects for quantum ground-state cooling seem extremely promising. Cavity-cooling without added stabilisation by feedback cooling remains challenging, but trapping at high vacuum in a cavity is now possible through the addition of a Paul trap. However, the Paul trap has been found to qualitatively modify the cavity output spectrum, with the latter acquiring an atypical ‘split-sideband’ structure, of different form from the displacement spectrum, and which depends on N, the optical well at which the particle localises. In the present work we investigate the N-dependence of the dynamics, in particular with respect to thermometry: we show that in strong cooling regions N≳ 100, the temperature may still be reliably inferred from the cavity output spectra. We also explain the N-dependence of the mechanical frequencies and optomechanical coupling showing that these may be accurately estimated. We present a simple ‘fast-cavity’ model for the cavity output and test all our findings against full numerical solutions of the nonlinear stochastic equations of motion for the system.
Quantum simulation of spin models on an arbitrary lattice with trapped ions
International Nuclear Information System (INIS)
Korenblit, S; Kafri, D; Campbell, W C; Islam, R; Edwards, E E; Monroe, C; Gong, Z-X; Lin, G-D; Duan, L-M; Kim, J; Kim, K
2012-01-01
A collection of trapped atomic ions represents one of the most attractive platforms for the quantum simulation of interacting spin networks and quantum magnetism. Spin-dependent optical dipole forces applied to an ion crystal create long-range effective spin–spin interactions and allow the simulation of spin Hamiltonians that possess nontrivial phases and dynamics. Here we show how the appropriate design of laser fields can provide for arbitrary multidimensional spin–spin interaction graphs even for the case of a linear spatial array of ions. This scheme uses currently available trap technology and is scalable to levels where the classical methods of simulation are intractable. (paper)
Ejection of Coulomb Crystals from a Linear Paul Ion Trap for Ion-Molecule Reaction Studies.
Meyer, K A E; Pollum, L L; Petralia, L S; Tauschinsky, A; Rennick, C J; Softley, T P; Heazlewood, B R
2015-12-17
Coulomb crystals are being increasingly employed as a highly localized source of cold ions for the study of ion-molecule chemical reactions. To extend the scope of reactions that can be studied in Coulomb crystals-from simple reactions involving laser-cooled atomic ions, to more complex systems where molecular reactants give rise to multiple product channels-sensitive product detection methodologies are required. The use of a digital ion trap (DIT) and a new damped cosine trap (DCT) are described, which facilitate the ejection of Coulomb-crystallized ions onto an external detector for the recording of time-of-flight (TOF) mass spectra. This enables the examination of reaction dynamics and kinetics between Coulomb-crystallized ions and neutral molecules: ionic products are typically cotrapped, thus ejecting the crystal onto an external detector reveals the masses, identities, and quantities of all ionic species at a selected point in the reaction. Two reaction systems are examined: the reaction of Ca(+) with deuterated isotopologues of water, and the charge exchange between cotrapped Xe(+) with deuterated isotopologues of ammonia. These reactions are examples of two distinct types of experiment, the first involving direct reaction of the laser-cooled ions, and the second involving reaction of sympathetically-cooled heavy ions to form a mixture of light product ions. Extensive simulations are conducted to interpret experimental results and calculate optimal operating parameters, facilitating a comparison between the DIT and DCT approaches. The simulations also demonstrate a correlation between crystal shape and image shape on the detector, suggesting a possible means for determining crystal geometry for nonfluorescing ions.
International Nuclear Information System (INIS)
Yeo, Yee Ngee; Wang Yingqian; Samanta, Santanu Kumar; Yoo, Won Jong; Samudra, Ganesh; Gao, Dongyue; Chong, Chee Ching
2006-01-01
We investigated the trapping properties of high κ material as the charge storage layer in non-volatile flash memory devices using a two-dimensional device simulator, Medici. The high κ material is sandwiched between two silicon oxide layers, resulting in the Silicon-Oxide-High κ-Oxide-Silicon (SOHOS) structure. The trap energy levels of the bulk electron traps in high κ material were determined. The programming and erasing voltage and time using Fowler Nordheim tunneling were estimated by simulation. The effect of deep level traps on erasing was investigated. Also, the effect of bulk traps density, thickness of block oxide and thickness of high κ material on the threshold voltage of the device was simulated
Energy Technology Data Exchange (ETDEWEB)
Steiner, P.
1994-01-01
The contribution reflects an interview with the nuclear physicist Prof. Dr. Wolfgang Paul, to whom the Nobel prize has been awarded for the electro-magnetic trap for loaded and unloaded particles named after him. The centre of the discussion is the professional development with regard to main fields of research. (BWI)
Electrostatic ion trap and Fourier transform measurements for high-resolution mass spectrometry
International Nuclear Information System (INIS)
Bhushan, K. G.; Gadkari, S. C.; Yakhmi, J. V.; Sahni, V. C.
2007-01-01
We report on the development of an electrostatic ion trap for high-resolution mass spectrometry. The trap works on purely electrostatic fields and hence trapping and storing of ions is not mass restrictive, unlike other techniques based on Penning, Paul, or radio frequency quadrupole ion traps. It allows simultaneous trapping and studying of multiple mass species over a large mass range. Mass spectra were recorded in ''dispersive'' and ''self-bunching'' modes of ions. Storage lifetimes of about 100 ms and mass resolving power of about 20 000 could be achieved from the fifth harmonic Fourier transform spectrum of Xe ions recorded in the self-bunching mode
Trapped ion simulation of molecular spectrum
Shen, Yangchao; Lu, Yao; Zhang, Kuan; Zhang, Shuaining; Huh, Joonsuk; Kim, Kihwan
2016-05-01
Boson sampling had been suggested as a classically intractable and quantum mechanically manageable problem via computational complexity theory arguments. Recently, Huh and co-workers proposed theoretically a modified version of boson sampling, which is designed to simulate a molecular problem, as a practical application. Here, we report the experimental implementation of the theoretical proposal with a trapped ion system. As a first demonstration, we perform the quantum simulation of molecular vibronic profile of SO2, which incorporates squeezing, rotation and coherent displacements operations, and the collective projection measurement on phonon modes. This work was supported by the National Basic Research Program of China 11CBA00300, 2011CBA00301, National Natural Science Foundation of China 11374178, 11574002. Basic Science Research Program of Korea NRF-2015R1A6A3A04059773.
Sognenavne, Aarhus Kommune (57 artikler). trap.dk
DEFF Research Database (Denmark)
Kællerød, Lars-Jakob Harding
2019-01-01
, Mejlby, Møllevang, Mårslet, Mårslev, Ormslev, Ravnsbjerg, Risskov, Sabro, Sankt Johannes, Sankt Lukas, Sankt Markus, Sankt Paul, Skejby, Skelager, Skjoldhøj, Skæring, Skødstrup, Skåde, Spørring, Sønder Årslev, Tilst, Tiset, Todbjerg, Tranbjerg, Trige, Tulstrup, Vejlby, Viby, Vitved, Vor Frue Sogn, Ølsted......Artikler til Trap Danmarks netpublikation trap.dk Sognenavnene Astrup, Beder, Borum, Brabrand, Christians Sogn, Egå, Elev, Ellevang, Elsted, Framlev, Fredens Sogn, Fårup, Gellerup, Hasle, Harlev, Helligånds Sogn, Hjortshøj, Holme, Hvilsted, Kasted, Kolt, Langenæs, Lisbjerg, Lyngby, Lystrup, Malling...
Calculation of the transport processes in an ambipolar trap by direct statistic simulation
International Nuclear Information System (INIS)
Lysyanskij, P.B.; Tiunov, M.A.; Fomel', B.M.
1982-01-01
Plasma of an open magnetic trap is simulated with a set of test particles. Transverse drift movement of particles in axial-asymmetric magnetic fields is described with the method of finite transformations. Effects of collisions are simulated with arbitrary changes of velocity vectors of test particles which corresponds to their scattering with ''background'' plasma. The model takes account of longitudinal and transverse losses as well as atomic beam injection. The simulation permitted to obtain values and characteristics of longitudinal and transverse loss flows, ion temperature and radial profile of ma density in the central part of the ''AMBALplas'' ambipolar trap
Electrodynamically trapped Yb+ ions for quantum information processing
International Nuclear Information System (INIS)
Balzer, Chr.; Braun, A.; Hannemann, T.; Wunderlich, Chr.; Paape, Chr.; Ettler, M.; Neuhauser, W.
2006-01-01
Highly efficient, nearly deterministic, and isotope selective generation of Yb + ions by one- and two-color photoionization is demonstrated. State preparation and state selective detection of hyperfine states in 171 Yb + is investigated in order to optimize the purity of the prepared state and to time-optimize the detection process. Linear laser-cooled Yb + ion crystals confined in a Paul trap are demonstrated. Advantageous features of different previous ion trap experiments are combined, while at the same time the number of possible error sources is reduced by using a comparatively simple experimental apparatus. This opens a new path toward quantum state manipulation of individual trapped ions, and in particular, to scalable quantum computing
Directory of Open Access Journals (Sweden)
Henrique Silva Furtado
2009-09-01
Full Text Available Numerical simulation of solute trapping during solidification, using two phase-field model for dilute binary alloys developed by Kim et al. [Phys. Rev. E, 60, 7186 (1999] and Ramirez et al. [Phys. Rev. E, 69, 05167 (2004] is presented here. The simulations on dilute Cu-Ni alloy are in good agreement with one dimensional analytic solution of sharp interface model. Simulation conducted under small solidification velocity using solid-liquid interface thickness (2λ of 8 nanometers reproduced the solute (Cu equilibrium partition coefficient. The spurious numerical solute trapping in solid phase, due to the interface thickness was negligible. A parameter used in analytical solute trapping model was determined by isothermal phase-field simulation of Ni-Cu alloy. Its application to Si-As and Si-Bi alloys reproduced results that agree reasonably well with experimental data. A comparison between the three models of solute trapping (Aziz, Sobolev and Galenko [Phys. Rev. E, 76, 031606 (2007] was performed. It resulted in large differences in predicting the solidification velocity for partition-less solidification, indicating the necessity for new and more acute experimental data.
Sink strength simulations using the Monte Carlo method: Applied to spherical traps
Ahlgren, T.; Bukonte, L.
2017-12-01
The sink strength is an important parameter for the mean-field rate equations to simulate temporal changes in the micro-structure of materials. However, there are noteworthy discrepancies between sink strengths obtained by the Monte Carlo and analytical methods. In this study, we show the reasons for these differences. We present the equations to estimate the statistical error for sink strength calculations and show the way to determine the sink strengths for multiple traps. We develop a novel, very fast Monte Carlo method to obtain sink strengths. The results show that, in addition to the well-known sink strength dependence of the trap concentration, trap radius and the total sink strength, the sink strength also depends on the defect diffusion jump length and the total trap volume fraction. Taking these factors into account, allows us to obtain a very accurate analytic expression for the sink strength of spherical traps.
Li, Jing; Wu, Xiaoping
2011-10-10
In this paper a model of the trapping force on nanowires is built by three dimensional finite-difference time-domain (FDTD) and Maxwell stress tensor methods, and the tightly focused laser beam is expressed by spherical vector wave functions (VSWFs). The trapping capacities on nanoscale-diameter nanowires are discussed in terms of a strongly focused linearly polarized beam and radially polarized beam. Simulation results demonstrate that the radially polarized beam has higher trapping efficiency on nanowires with higher refractive indices than linearly polarized beam.
International Nuclear Information System (INIS)
Ristic, G.F.; Jaksic, A.B.; Pejovic, M.M.
1999-01-01
The paper presents new experimental evidence of the latent interface-trap buildup during annealing of gamma-ray irradiated power VDMOSFETs. We try to reveal the nature of this still ill-understood phenomenon by isothermal annealing, switching temperature annealing and switching bias annealing experiments. The results of numerical simulation of interface-trap kinetics during annealing are also shown. (authors)
International Nuclear Information System (INIS)
Allcock, D T C; Sherman, J A; Stacey, D N; Burrell, A H; Curtis, M J; Imreh, G; Linke, N M; Szwer, D J; Webster, S C; Steane, A M; Lucas, D M
2010-01-01
We describe a new electrode design for a surface-electrode Paul trap, which allows rotation of the normal modes out of the trap plane, and a technique for micromotion compensation in all directions using a two-photon process, which avoids the need for an ultraviolet laser directed to the trap plane. The fabrication and characterization of the trap are described, as well as its implementation for the trapping and cooling of single Ca + ions. We also propose a repumping scheme that increases ion fluorescence and simplifies heating rate measurements obtained by time-resolved ion fluorescence during Doppler cooling.
Allcock, D. T. C.; Sherman, J. A.; Stacey, D. N.; Burrell, A. H.; Curtis, M. J.; Imreh, G.; Linke, N. M.; Szwer, D. J.; Webster, S. C.; Steane, A. M.; Lucas, D. M.
2010-05-01
We describe a new electrode design for a surface-electrode Paul trap, which allows rotation of the normal modes out of the trap plane, and a technique for micromotion compensation in all directions using a two-photon process, which avoids the need for an ultraviolet laser directed to the trap plane. The fabrication and characterization of the trap are described, as well as its implementation for the trapping and cooling of single Ca+ ions. We also propose a repumping scheme that increases ion fluorescence and simplifies heating rate measurements obtained by time-resolved ion fluorescence during Doppler cooling.
Integrated fiber-mirror ion trap for strong ion-cavity coupling
International Nuclear Information System (INIS)
Brandstätter, B.; Schüppert, K.; Casabone, B.; Friebe, K.; Stute, A.; Northup, T. E.; McClung, A.; Schmidt, P. O.; Deutsch, C.; Reichel, J.; Blatt, R.
2013-01-01
We present and characterize fiber mirrors and a miniaturized ion-trap design developed to integrate a fiber-based Fabry-Perot cavity (FFPC) with a linear Paul trap for use in cavity-QED experiments with trapped ions. Our fiber-mirror fabrication process not only enables the construction of FFPCs with small mode volumes, but also allows us to minimize the influence of the dielectric fiber mirrors on the trapped-ion pseudopotential. We discuss the effect of clipping losses for long FFPCs and the effect of angular and lateral displacements on the coupling efficiencies between cavity and fiber. Optical profilometry allows us to determine the radii of curvature and ellipticities of the fiber mirrors. From finesse measurements, we infer a single-atom cooperativity of up to 12 for FFPCs longer than 200 μm in length; comparison to cavities constructed with reference substrate mirrors produced in the same coating run indicates that our FFPCs have similar scattering losses. We characterize the birefringence of our fiber mirrors, finding that careful fiber-mirror selection enables us to construct FFPCs with degenerate polarization modes. As FFPCs are novel devices, we describe procedures developed for handling, aligning, and cleaning them. We discuss experiments to anneal fiber mirrors and explore the influence of the atmosphere under which annealing occurs on coating losses, finding that annealing under vacuum increases the losses for our reference substrate mirrors. X-ray photoelectron spectroscopy measurements indicate that these losses may be attributable to oxygen depletion in the mirror coating. Special design considerations enable us to introduce a FFPC into a trapped ion setup. Our unique linear Paul trap design provides clearance for such a cavity and is miniaturized to shield trapped ions from the dielectric fiber mirrors. We numerically calculate the trap potential in the absence of fibers. In the experiment additional electrodes can be used to compensate
Simulating tritium retention in tungsten with a multiple trap model in the TMAP code
International Nuclear Information System (INIS)
Merrill, Brad J.; Shimada, Masashi; Humrickhouse, Paul W.
2013-01-01
Accurately predicting the quantity of tritium retained in plasma facing components is a key safety issue for licensing future fusion power reactors. Retention of tritium in the lattice damage caused when high energy neutrons collide with atoms in the structural material of the reactor's plasma facing components (PFCs) is an area of ongoing experimental research at the Idaho National Laboratory (INL) under the US/Japan TITAN collaboration. Recent experiments with the Tritium Plasma Experiment (TPE), located in the INL's Safety and Tritium Applied Research (STAR) facility, demonstrate that this damage can only be simulated by computer codes like the Tritium Migration Analysis Program (TMAP) if one assumes that the lattice damage produced by these neutrons results in multiple types of hydrogen traps (energy wells) within the material, each possessing a different trap energy and density. Previous attempts to simulate the quantity of deuterium released from neutron irradiated TPE tungsten targets indicated that at least six different traps are required by TMAP to model this release. In this paper we describe a recent extension of the TMAP trap site model to include as many traps as required by the user to simulate retention of tritium in neutron damaged tungsten. This model has been applied to data obtained for tungsten irradiated to a damage level of 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) after exposure to a plasma in TPE. (author)
[Lea Kõiv. Paul Johansen und das Stadtarchiv Reval/Tallinn] / Paul Kaegbein
Kaegbein, Paul
2008-01-01
Arvustus: Lea Kõiv. Paul Johansen und das Stadtarchiv Reval/Tallinn. - Nordosteuropa als Geschichtsregion. Helsinki : Aue-Stiftung; Lübeck : Schmict-Röhmild, 2006. Lk. 45-59. Artiklis on kasutatud seni avalikkusele vähetuntud materjale ja osaliselt käsitletud avalikke vaidlusi, kuhu olid segatud nii Paul Johansen kui järgmine linnaarhivaar Rudolf Kenkmaa
Trapped-Particle Instability Leading to Bursting in Stimulated Raman Scattering Simulations
International Nuclear Information System (INIS)
Brunner, S.; Valeo, E.
2001-01-01
Nonlinear, kinetic simulations of Stimulated Raman Scattering (SRS) for laser-fusion-relevant conditions present a bursting behavior. Different explanations for this regime has been given in previous studies: Saturation of SRS by increased nonlinear Landau damping [K. Estabrook et al., Phys. Fluids B 1 (1989) 1282] and detuning due to the nonlinear frequency shift of the plasma wave [H.X. Vu et al., Phys. Rev. Lett. 86 (2001) 4306]. Another mechanism, also assigning a key role to the trapped electrons, is proposed here: The break-up of the plasma wave through the trapped-particle instability
Karjas on ohutum elada / Toomas Paul
Paul, Toomas, 1939-
2003-01-01
Vt. ka Paul, Toomas. "Löö esimesena, Freddy!". Eesti Päevaleht, 8. mai 2003. Inimesest kui karjaloomast, inimloomusest ja sallivusest. Ilm. ka: Paul, Toomas. Ole salliv, Bob // Pastishsh & popurrii : ilmavaatlusi / Paul, Toomas. - [Tallinn] : Oomen, 2007. - Lk. 54-58
Injection into electron plasma traps
International Nuclear Information System (INIS)
Gorgadze, Vladimir; Pasquini, Thomas A.; Fajans, Joel; Wurtele, Jonathan S.
2003-01-01
Computational studies and experimental measurements of plasma injection into a Malmberg-Penning trap reveal that the number of trapped particles can be an order of magnitude higher than predicted by a simple estimates based on a ballistic trapping model. Enhanced trapping is associated with a rich nonlinear dynamics generated by the space-charge forces of the evolving trapped electron density. A particle-in-cell simulation is used to identify the physical mechanisms that lead to the increase in trapped electrons. The simulations initially show strong two-stream interactions between the electrons emitted from the cathode and those reflected off the end plug of the trap. This is followed by virtual cathode oscillations near the injection region. As electrons are trapped, the initially hollow longitudinal phase-space is filled, and the transverse radial density profile evolves so that the plasma potential matches that of the cathode. Simple theoretical arguments are given that describe the different dynamical regimes. Good agreement is found between simulation and theory
Fromm, Steven
2017-09-01
In an effort to study and improve the optical trapping efficiency of the 225Ra Electric Dipole Moment experiment, a fully parallelized Monte Carlo simulation of the laser cooling and trapping apparatus was created at Argonne National Laboratory and now maintained and upgraded at Michigan State University. The simulation allows us to study optimizations and upgrades without having to use limited quantities of 225Ra (15 day half-life) in experiment's apparatus. It predicts a trapping efficiency that differs from the observed value in the experiment by approximately a factor of thirty. The effects of varying oven geometry, background gas interactions, laboratory magnetic fields, MOT laser beam configurations and laser frequency noise were studied and ruled out as causes of the discrepancy between measured and predicted values of the overall trapping efficiency. Presently, the simulation is being used to help optimize a planned blue slower laser upgrade in the experiment's apparatus, which will increase the overall trapping efficiency by up to two orders of magnitude. This work is supported by Michigan State University, the Director's Research Scholars Program at the National Superconducting Cyclotron Laboratory, and the U.S. DOE, Office of Science, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.
Development of a radiofrequency linear ion trap for {beta} decay study
Energy Technology Data Exchange (ETDEWEB)
Li, G. [McGill Univ., Montreal, Quebec (Canada); Argonne National Laboratory, Argonne, Illinois (United States); Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, California (United States); Segel, R.E. [Northwestern Univ., Illinois (United States); and others
2010-07-01
A Beta decay Paul Trap (BPT) has been constructed at Argonne National Laboratory for the precise measurement of beta decay. We have demonstrated the capability of producing and transferring a low-energy, bunched, and isotopically pure ions beam. In BPT the ions are cooled to sub-eV energies, and confined in a volume of less than 1 mm{sup 3}. The trap has an open geometry which allows four sets of radiation detectors covering a substantial potion of solid angle. In combination with versatile detectors, BPT is able to precisely determine the entire decay kinematics of many isotopes. (author)
Dynamic analysis of trapping and escaping in dual beam optical trap
Li, Wenqiang; Hu, Huizhu; Su, Heming; Li, Zhenggang; Shen, Yu
2016-10-01
In this paper, we simulate the dynamic movement of a dielectric sphere in optical trap. This dynamic analysis can be used to calibrate optical forces, increase trapping efficiency and measure viscous coefficient of surrounding medium. Since an accurate dynamic analysis is based on a detailed force calculation, we calculate all forces a sphere receives. We get the forces of dual-beam gradient radiation pressure on a micron-sized dielectric sphere in the ray optics regime and utilize Einstein-Ornstein-Uhlenbeck to deal with its Brownian motion forces. Hydrodynamic viscous force also exists when the sphere moves in liquid. Forces from buoyance and gravity are also taken into consideration. Then we simulate trajectory of a sphere when it is subject to all these forces in a dual optical trap. From our dynamic analysis, the sphere can be trapped at an equilibrium point in static water, although it permanently fluctuates around the equilibrium point due to thermal effects. We go a step further to analyze the effects of misalignment of two optical traps. Trapping and escaping phenomena of the sphere in flowing water are also simulated. In flowing water, the sphere is dragged away from the equilibrium point. This dragging distance increases with the decrease of optical power, which results in escaping of the sphere with optical power below a threshold. In both trapping and escaping process we calculate the forces and position of the sphere. Finally, we analyze a trapping region in dual optical tweezers.
Graded-index fiber tip optical tweezers: numerical simulation and trapping experiment.
Gong, Yuan; Ye, Ai-Yan; Wu, Yu; Rao, Yun-Jiang; Yao, Yao; Xiao, Song
2013-07-01
Optical fiber tweezers based on a graded-index multimode fiber (GIMMF) tip is proposed. Light propagation characteristics and gradient force distribution near the GIMMF tip are numerically investigated, which are further compared with that of optical fiber tips based on conventional single mode fibers. The simulated results indicated that by selecting optimal GIMMF length, the gradient force of the GIMMF tip tweezers is about 4 times higher than that of the SMF tip tweezers with a same shape. To prove the feasibility of such a new concept, optical trapping of yeast cells with a diameter of ~5 μm using the chemically-etched GIMMF tip is experimentally demonstrated and the trapping force is also calculated.
Ra+ ion trapping : toward an atomic parity violation measurement and an optical clock
Portela, M. Nunez; Dijck, E. A.; Mohanty, A.; Bekker, H.; van den Berg, Joost E.; Giri, G. S.; Hoekstra, S.; Onderwater, C. J. G.; Schlesser, S.; Timmermans, R.G.E.; Versolato, O. O.; Willmann, L.; Wilschut, H. W.; Jungmann, K.
2014-01-01
A single Ra+ ion stored in a Paul radio frequency ion trap has excellent potential for a precision measurement of the electroweak mixing angle at low momentum transfer and as the most stable optical clock. The effective transport and cooling of singly charged ions of the isotopes Ra-209 to Ra-214 in
Deuterium trapping in tungsten
Poon, Michael
Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation. Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation. The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D2 molecules inside the void with a trap energy of 1.2 eV. Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D
Deuterium trapping in tungsten
International Nuclear Information System (INIS)
Poon, M.
2004-01-01
Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. . Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D 2 molecules inside the void with a trap energy of 1.2 eV. . Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D
Deuterium trapping in tungsten
Energy Technology Data Exchange (ETDEWEB)
Poon, M
2004-07-01
Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. . Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D{sub 2} molecules inside the void with a trap energy of 1.2 eV. . Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D
Epistemologi Anarkhis Paul Feyerabend dan Implikasinya terhadap Pemikiran Islam
Directory of Open Access Journals (Sweden)
Abdul Aziz Faradi
2014-11-01
Full Text Available Nowadays, Islamic thought is trapped on the stagnancy of ideas. Such condition happens because the function of Islam changes, from an instrument for freedom to a rigid system of ideology. The similar pattern of change identified by Feyerabend also exists in the modern science. The similarity of the pattern inspired the writer to elaborate the concept of anarchy epistemology of Paul Feyerabend and its implication to the Islamic thought. This article uses philosophical hermeneutic approach by Gadamer in investigating meaningful sense of Feyerabend thought. The conclusion of the study ends up with the importance of returning Islamic thought to the pluralistic environment because Islam itself was not burn in a single thought but at least there are three epistemic patrons; Bayani, Burhani, and ‘Irfani.
CERN Bulletin
2010-01-01
When a group of physicists entered the Main Auditorium, during the evening of 29 June, they felt they had opened a time portal. Paul Dirac in front of a blackboard showing his formula. ©Sandra Hoogeboom An attentive audience, dressed in early 1900 costumes, were watching a lecture by the elusive Paul Dirac, presenting for the first time his famous formula on the blackboard. Paul Adrien Maurice Dirac (1902-1984) was a British mathematical physicist at Cambridge, and one of the "fathers" of quantum mechanics. When he first wrote it, in 1928, Dirac was not sure what his formula really meant. As demonstrated by Andersson four year later, what Dirac had written on the blackboard was the first definition of a positron, hence he is credited with having anticipated the existence of antimatter. The actor John Kohl performs as Paul Dirac. ©Sandra Hoogeboom What the group of puzzled physicists were really observing when they entered the CERN Auditorium was the shoo...
Improvements in the injection system of the Canadian Penning trap mass spectrometer
Clark, J; Boudreau, C; Buchinger, F; Crawford, J E; Gulick, S; Hardy, J C; Heinz, A; Lee, J K P; Moore, R B; Savard, G; Seweryniak, D; Sharma, K S; Sprouse, G; Vaz, J; Wang, J C; Zhou, Z
2003-01-01
The Canadian Penning Trap (CPT) mass spectrometer is designed to make precise mass measurements on a variety of stable and short-lived isotopes. Modifications to the injection system of the CPT have been implemented in recent months, the purpose being to more efficiently collect and transfer weakly-produced reaction products from the target to the Penning trap. These include a magnetic triplet situated after the target chamber to increase the acceptance of the Enge spectrograph, a velocity filter to more effectively separate the beam from the reaction products and the replacement of the Paul trap with a linear trap resulting in more efficient capture and accumulation of ions from the ion cooler. This paper will discuss these recent modifications and how they have increased our ability in making mass measurements on isotopes of low abundance, including those from a sup 2 sup 5 sup 2 Cf fission source.
Pais, Abraham; Jacob, Maurice; Olive, David I.; Atiyah, Michael F.
2005-09-01
Preface Peter Goddard; Dirac memorial address Stephen Hawking; 1. Paul Dirac: aspects of his life and work Abraham Pais; 2. Antimatter Maurice Jacob; 3. The monopole David Olive; 4. The Dirac equation and geometry Michael F. Atiyah.
In Conversation with Paul Richards
Holman, Andrew
2013-01-01
Paul Richards is one of those individuals who make a difference and is as far from institutional as one can be. The author met up with him at the Learning Disability Today conference in London to talk more about his work and life. Paul coordinates the service user involvement across Southdown Housing Association, based in Sussex.
Molecular dynamics simulation of electron trapping in the sapphire lattice
International Nuclear Information System (INIS)
Rambaut, C.; Oh, K.H.; Fayeulle, S.; Kohanoff, J.
1995-10-01
Energy storage and release in dielectric materials can be described on the basis of the charge trapping mechanism. Most phenomenological aspects have been recently rationalized in terms of the space charge mode. Dynamical aspects are studied here by performing Molecular Dynamics simulations. We show that an excess electron introduced into the sapphire lattice (α -Al 2 O 3 ) can be trapped only at a limited number of sites. The energy gained by allowing the electron to localize in these sites is of the order of 4-5 eV, in good agreement with the results of the space charge model. Displacements of the neighboring ions due to the implanted charge are shown to be localized in a small region of about 5 A. Detrapping is observed at 250 K. The ionic displacements turn out to play an important role in modifying the potential landscape by lowering, in a dynamical way, the barriers that cause localization at low temperature. (author). 18 refs, 7 figs, 2 tabs
Ära pabista, Sam! / Toomas Paul
Paul, Toomas, 1939-
2003-01-01
Inimese võimest leida lohutust täieliku lootusetuse olukorras ja võimetusest ette näha, milliste tulemusteni tema tegevus lõpuks viib. Ilm. ka: Paul, Toomas. Riskiveski krigin // Pastishsh & popurrii : ilmavaatlusi / Paul, Toomas. - [Tallinn] : Oomen, 2007. - Lk. 133-139
2012-01-01
Mr Paul Levaux, a long-standing member of the Belgian delegation to the Finance Committee and Council, passed away on 3 December 2012. Paul Levaux first attended the CERN Council and Finance Committee in June 1970 as an Advisor, although his association with CERN goes back to the 1960s. From October 1970 until December 2007 he represented Belgium in the capacity of Council and Finance Committee delegate. He was Finance Committee Chairman from 1971 to 1973 and President of Council from 1975 to June 1978. He also served as Vice-President of Council from January 1978 until December 1980 with a second term from January 1994 to December 1997. In addition to holding these important offices, Paul Levaux participated in an extensive number of CERN working groups. In particular, he was a member of the Working Group on Procedures for Payment of Member States' Contributions (2000-2001) and Working Group on the Review of the Tasks and Working Methods of CERN's Governing Bodies and Commi...
2012-01-01
Paul joined the Radiation Group at CERN's Laboratory II in March 1972. He carried out tests on materials and components that were used in the construction of the SPS. Following the commissioning of the SPS in 1975 and when the two laboratories were merged into one, Paul became a member of the Radiation Protection group. There, he had two roles: the first as a radiation protection officer in the underground areas, where access and personnel protection issues were of crucial importance; and the second testing the radioresistance of many different types of materials. Thanks to his detailed analyses and shrewd interpretation of the results, he became a recognised expert in the field - a recognition that extended far beyond the boundaries of CERN. He wrote many reports and co-authored several volumes of the CERN "yellow reports" issued as a catalogue on the radioresistance of materials and which continue to serve as reference works today. In July 1988 Paul ha...
Fukuda, Koichi; Asai, Hidehiro; Hattori, Junichi; Shimizu, Mitsuaki; Hashizume, Tamotsu
2018-04-01
In this study, GaN MOS capacitance-voltage device simulations considering various interface and bulk traps are performed in the transient mode. The simulations explain various features of capacitance-voltage curves, such as plateau, hysteresis, and frequency dispersions, which are commonly observed in measurements of GaN MOS capacitors and arise from complicated combinations of interface and bulk deep-level traps. The objective of the present study is to provide a good theoretical tool to understand the physics of various nonideal measured curves.
Paul Garrin / Paul Garrin ; interv. Tilman Baumgärtel
Garrin, Paul
2006-01-01
1997. a. New York Citys tehtud intervjuu ameerika kunstniku, firma pgMedia rajaja ja omaniku Paul Garriniga (sünd. 1952). P. Garrini videotest, pikemalt videost "Free Society", Internetiga tegelemisest, projektist "Mediafilter", interaktiivsetest installatsioonidest, domeeninimede registreerimise projektist "name.space"
Engineering Vibrationally Assisted Energy Transfer in a Trapped-Ion Quantum Simulator
Gorman, Dylan J.; Hemmerling, Boerge; Megidish, Eli; Moeller, Soenke A.; Schindler, Philipp; Sarovar, Mohan; Haeffner, Hartmut
2018-01-01
Many important chemical and biochemical processes in the condensed phase are notoriously difficult to simulate numerically. Often, this difficulty arises from the complexity of simulating dynamics resulting from coupling to structured, mesoscopic baths, for which no separation of time scales exists and statistical treatments fail. A prime example of such a process is vibrationally assisted charge or energy transfer. A quantum simulator, capable of implementing a realistic model of the system of interest, could provide insight into these processes in regimes where numerical treatments fail. We take a first step towards modeling such transfer processes using an ion-trap quantum simulator. By implementing a minimal model, we observe vibrationally assisted energy transport between the electronic states of a donor and an acceptor ion augmented by coupling the donor ion to its vibration. We tune our simulator into several parameter regimes and, in particular, investigate the transfer dynamics in the nonperturbative regime often found in biochemical situations.
Interview : Paul Paulus on group creativity
Harms, Rainer; Van Der Zee, Karen
Paul Paulus is Distinguished Professor of Psychology at the Department of Psychology, University of Texas at Arlington. Paul Paulus's research interests revolve around Group Creativity: On the one hand, creative processes are often conceptualized as individual-level phenomena. On the other hand,
Interview: Paul Paulus on group creativity
Harms, Rainer; van der Zee, Karen
2013-01-01
Paul Paulus is Distinguished Professor of Psychology at the Department of Psychology, University of Texas at Arlington. Paul Paulus's research interests revolve around Group Creativity: On the one hand, creative processes are often conceptualized as individual-level phenomena. On the other hand,
Trapped Electron Instability of Electron Plasma Waves: Vlasov simulations and theory
Berger, Richard; Chapman, Thomas; Brunner, Stephan
2013-10-01
The growth of sidebands of a large-amplitude electron plasma wave is studied with Vlasov simulations for a range of amplitudes (. 001 vph = +/-ωbe , where vph =ω0 /k0 and ωbe is the bounce frequency of a deeply trapped electron. In 2D simulations, we find that the instability persists and co-exists with the filamentation instability. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the Laboratory Research and Development Program at LLNL under project tracking code 12-ERD.
Kaegbein, Paul
2008-01-01
Arvustus: Heinz von zur Mühlen. Paul Johansen und die Sogenannten Undeutschen in Reval/Tallinn. - Nordosteuropa als Geschichtsregion. Helsinki : Aue-Stiftung :; Lübeck : Schmidt-Römhild, 2006. lk. 103-111. Paul Johanseni lähim töökaaslane kirjeldab teose "Deutsch und Undeutsch im mittelalterlichen und frühneuzeitlichen Reval" valmimist
Paul Callaghan luminous moments
Callaghan, Paul
2013-01-01
Acknowledged internationally for his ground-breaking scientific research in the field of magnetic resonance, Sir Paul Callaghan was a scientist and visionary with a rare gift for promoting science to a wide audience. He was named New Zealander of the Year in 2011. His death in early 2012 robbed New Zealand of an inspirational leader. Paul Callaghan: Luminous Moments brings together some of his most significant writing. Whether he describes his childhood in Wanganui, reflects on discovering the beauty of science, sets out New Zealand's future potential or discusses the experience of fa
A highly miniaturized vacuum package for a trapped ion atomic clock
Energy Technology Data Exchange (ETDEWEB)
Schwindt, Peter D. D., E-mail: pschwin@sandia.gov; Jau, Yuan-Yu; Partner, Heather; Casias, Adrian; Wagner, Adrian R.; Moorman, Matthew; Manginell, Ronald P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Kellogg, James R.; Prestage, John D. [Jet Propulsion Laboratory, Pasadena, California 91109 (United States)
2016-05-15
We report on the development of a highly miniaturized vacuum package for use in an atomic clock utilizing trapped ytterbium-171 ions. The vacuum package is approximately 1 cm{sup 3} in size and contains a linear quadrupole RF Paul ion trap, miniature neutral Yb sources, and a non-evaporable getter pump. We describe the fabrication process for making the Yb sources and assembling the vacuum package. To prepare the vacuum package for ion trapping, it was evacuated, baked at a high temperature, and then back filled with a helium buffer gas. Once appropriate vacuum conditions were achieved in the package, it was sealed with a copper pinch-off and was subsequently pumped only by the non-evaporable getter. We demonstrated ion trapping in this vacuum package and the operation of an atomic clock, stabilizing a local oscillator to the 12.6 GHz hyperfine transition of {sup 171}Y b{sup +}. The fractional frequency stability of the clock was measured to be 2 × 10{sup −11}/τ{sup 1/2}.
Light effect in photoionization of traps in GaN MESFETs
Directory of Open Access Journals (Sweden)
H. Arabshahi
2009-09-01
Full Text Available Trapping of hot electron behavior by trap centers located in buffer layer of a wurtzite phase GaN MESFET has been simulated using an ensemble Monte Carlo simulation. The results of the simulation show that the trap centers are responsible for current collapse in GaN MESFET at low temperatures. These electrical traps degrade the performance of the device at low temperature. On the opposite, a light-induced increase in the trap-limited drain current, results from the photoionization of trapped carriers and their return to the channel under the influence of the built in electric field associated with the trapped charge distribution. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible, and the predicted drain current and other electrical characteristics for the simulated device including trapping center effects show close agreement with the available experimental data.
Beta Neutrino Correlation Measurement with Trapped Radioactive Ions
International Nuclear Information System (INIS)
Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Mery, A.; Rodriguez, D.; Thomas, J.-C.
2010-01-01
The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6 He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.
James Peacock, Understanding Paul Auster
Directory of Open Access Journals (Sweden)
Chrysavgi Papayianni
2011-10-01
Full Text Available Paul Auster’s impressive gamut of work continues to incite fascination and controversy. Indeed, his compelling storytelling style taken together with his mixing of crime fiction and absurdism has made his readers and critics vacillate between praise and condemnation. James Peacock’s Understanding Paul Auster, sheds new light to otherwise obscure aspects of Auster’s novels, films, and other works undermining in this way the negative criticism of the past and thus creating a new appreciation fo...
Novel Ion Trap Design for Strong Ion-Cavity Coupling
Directory of Open Access Journals (Sweden)
Alejandro Márquez Seco
2016-04-01
Full Text Available We present a novel ion trap design which facilitates the integration of an optical fiber cavity into the trap structure. The optical fibers are confined inside hollow electrodes in such a way that tight shielding and free movement of the fibers are simultaneously achievable. The latter enables in situ optimization of the overlap between the trapped ions and the cavity field. Through numerical simulations, we systematically analyze the effects of the electrode geometry on the trapping characteristics such as trap depths, secular frequencies and the optical access angle. Additionally, we simulate the effects of the presence of the fibers and confirm the robustness of the trapping potential. Based on these simulations and other technical considerations, we devise a practical trap configuration that isviable to achieve strong coupling of a single ion.
International Nuclear Information System (INIS)
Holder, J.P.; Church, D.A.; Gruber, L.; DeWitt, H.E.; Beck, B.R.; Schneider, D.
2000-01-01
Molecular dynamics simulations are used to help design new experiments by modeling the cooling of small numbers of trapped multiply charged ions by Coulomb interactions with laser-cooled Be + ions. A Verlet algorithm is used to integrate the equations of motion of two species of point ions interacting in an ideal Penning trap. We use a time step short enough to follow the cyclotron motion of the ions. Axial and radial temperatures for each species are saved periodically. Direct heating and cooling of each species in the simulation can be performed by periodically rescaling velocities. Of interest are Fe 11+ due to a EUV-optical double resonance for imaging and manipulating the ions, and Ca 14+ since a ground state fine structure transition has a convenient wavelength in the tunable laser range
The intermediate state in Paul
Directory of Open Access Journals (Sweden)
N. S. L. Fryer
1987-01-01
Full Text Available The point of view taken in this paper is that the apostle Paul envisions, between death and the resurrection of the body at the Parousia, an interim period during which the disembodied soul is in the immediate presence of Christ, though in a state of 'nakedness'. The background of Paul's view lies neither in contemporary Hellenistic religious-philosophical speculations nor in 'late-Judaism'. Two crucial 'forces' in particular moulded his perspective, viz the teachings of Jesus and His own rapture to 'Paradise'.
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)
Quantum Simulation of a Lattice Schwinger Model in a Chain of Trapped Ions
Directory of Open Access Journals (Sweden)
P. Hauke
2013-11-01
Full Text Available We discuss how a lattice Schwinger model can be realized in a linear ion trap, allowing a detailed study of the physics of Abelian lattice gauge theories related to one-dimensional quantum electrodynamics. Relying on the rich quantum-simulation toolbox available in state-of-the-art trapped-ion experiments, we show how one can engineer an effectively gauge-invariant dynamics by imposing energetic constraints, provided by strong Ising-like interactions. Applying exact diagonalization to ground-state and time-dependent properties, we study the underlying microscopic model and discuss undesired interaction terms and other imperfections. As our analysis shows, the proposed scheme allows for the observation in realistic setups of spontaneous parity- and charge-symmetry breaking, as well as false-vacuum decay. Besides an implementation aimed at larger ion chains, we also discuss a minimal setting, consisting of only four ions in a simpler experimental setup, which enables us to probe basic physical phenomena related to the full many-body problem. The proposal opens a new route for analog quantum simulation of high-energy and condensed-matter models where gauge symmetries play a prominent role.
Quantum simulation of the integer factorization problem: Bell states in a Penning trap
Rosales, Jose Luis; Martin, Vicente
2018-03-01
The arithmetic problem of factoring an integer N can be translated into the physics of a quantum device, a result that supports Pólya's and Hilbert's conjecture to demonstrate Riemann's hypothesis. The energies of this system, being univocally related to the factors of N , are the eigenvalues of a bounded Hamiltonian. Here we solve the quantum conditions and show that the histogram of the discrete energies, provided by the spectrum of the system, should be interpreted in number theory as the relative probability for a prime to be a factor candidate of N . This is equivalent to a quantum sieve that is shown to require only o (ln√{N}) 3 energy measurements to solve the problem, recovering Shor's complexity result. Hence the outcome can be seen as a probability map that a pair of primes solve the given factorization problem. Furthermore, we show that a possible embodiment of this quantum simulator corresponds to two entangled particles in a Penning trap. The possibility to build the simulator experimentally is studied in detail. The results show that factoring numbers, many orders of magnitude larger than those computed with experimentally available quantum computers, is achievable using typical parameters in Penning traps.
Nallatamby, Jean-Christophe; Abdelhadi, Khaled; Jacquet, Jean-Claude; Prigent, Michel; Floriot, Didier; Delage, Sylvain; Obregon, Juan
2013-03-01
Commercially available simulators present considerable advantages in performing accurate DC, AC and transient simulations of semiconductor devices, including many fundamental and parasitic effects which are not generally taken into account in house-made simulators. Nevertheless, while the TCAD simulators of the public domain we have tested give accurate results for the simulation of diffusion noise, none of the tested simulators perform trap-assisted GR noise accurately. In order to overcome the aforementioned problem we propose a robust solution to accurately simulate GR noise due to traps. It is based on numerical processing of the output data of one of the simulators available in the public-domain, namely SENTAURUS (from Synopsys). We have linked together, through a dedicated Data Access Component (DAC), the deterministic output data available from SENTAURUS and a powerful, customizable post-processing tool developed on the mathematical SCILAB software package. Thus, robust simulations of GR noise in semiconductor devices can be performed by using GR Langevin sources associated to the scalar Green functions responses of the device. Our method takes advantage of the accuracy of the deterministic simulations of electronic devices obtained with SENTAURUS. A Comparison between 2-D simulations and measurements of low frequency noise on InGaP-GaAs heterojunctions, at low as well as high injection levels, demonstrates the validity of the proposed simulation tool.
2001-01-01
Paul Falk-Vairant died on 9 March 2001, a few weeks before his eightieth birthday. A physicist with dual Swiss and French nationality, he left his mark on particle physics in France and had a great impact on the development of CERN. Educated at the Swiss Federal Polytechnic at Zürich, Paul Falk-Vairant arrived in France in 1947 to study for a thesis at the Radium Institute in Paris. Up until 1973, he was employed successively by the French CNRS, CEA and the University of Paris. During the same period, he came to lead the first experiment at CERN run by physicists from outside institutes at the PS. In 1971, he chaired the ECFA (European Committee for Future Accelerators) working group on SPS physics. It was therefore natural for CERN in 1972 to invite him to take over its research policy. From 1973 to 1976, he occupied the position of Director of Physics I Department at CERN before becoming Research Director for the whole of CERN until 1978. At the same time Paul Falk-Vairant guided the experimental...
International Nuclear Information System (INIS)
Broda, E.
1982-01-01
This is a short biography about Paul Ehrenfest, a famous austrian physicist and student of Ludwig Boltzmann. Ehrenfest contributed important work to thermodynamics and quantum mechanics (a.o. adiabatic invariants, and the Ehrenfest theorem). Broda describes not only his scientific research but also his interaction and relation to other famous physicist of his time, like Erwin Schrödinger, Albert Einstein and others. (nowak)
Energy Technology Data Exchange (ETDEWEB)
1975-09-01
The El Paso Paul Kayser, the world's largest LNG carrier, demonstrates not only the sophistication and skills of French shipbuilding technology but also the financial perils of the LNG game. Ordered along with 2 sister ships to transport LNG from Algeria to the US, the ship must now await the start-up of the new Kikda LNG plant, which has been delayed for an estimated 18 months. The Paul Kayser has a cargo capacity of 4.4 million cu ft, measures 922 ft overall, and has a deadweight of some 59,000 tons. The tanks were constructed according to the Gaz Transport technique using a double hull with Invar membranes. Labor involved with construction of the LNG tanks is estimated at 580,000 man-hr.
Asthenospheric percolation of alkaline melts beneath the St. Paul region (Central Atlantic Ocean)
Brunelli, Daniele; Seyler, Monique
2010-01-01
Two peridotite suites collected by submersible in the equatorial Atlantic Ocean (Hekinian et al., 2000) were studied for textures, modes, and in situ major and trace element compositions in pyroxenes. Dive SP12 runs along the immersed flank of the St. Peter and Paul Rocks islets where amphibole-bearing, ultramafic mylonites enriched in alkalies and incompatible elements are exposed (Roden et al., 1984), whereas dive SP03 sampled a small intra-transform spreading centre situated about 370 km east of the St. Peter and Paul Rocks. Both suites are characterized by undeformed, coarse-grained granular textures typical of abyssal peridotites, derived from residual mantle after ˜ 15% melting of a DMM source, starting in the garnet stability field. Trace element modelling, textures and lack of mineral zoning indicate that the residual peridotites were percolated, reacted and refertilized by ˜ 2.6% partially aggregated melts in the uppermost level of the melting region. This relatively large amount of refertilization is in agreement with the cold and thick lithosphere inferred by previous studies. Freezing of trapped melts occurred as the peridotite entered the conductive layer, resulting in late-stage crystallization of olivine, clinopyroxene, spinel, ± plagioclase. Chondrite-normalized REE patterns in clinopyroxenes from SP03 indicate that they last equilibrated with (ultra-) depleted partial melts. In contrast, REE concentrations in clinopyroxenes from SP12 display U and S shaped LREE-enriched patterns and the calculated compositions of the impregnating melts span the compositional range of the regional basalts, which vary from normal MORB to alkali basalt sometimes modified by chromatographic fractionation with no, or very limited, mineral reaction. Thus the mylonitic band forming the St. Peter and St. Paul Rocks ridge is not a fragment of subcontinental lithospheric mantle left behind during the opening of the Central Atlantic, nor the source of the alkaline basalts
Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap
Energy Technology Data Exchange (ETDEWEB)
Schulz, Stephan A; Poschinger, Ulrich; Ziesel, Frank; Schmidt-Kaler, Ferdinand [Universitaet Ulm, Institut fuer Quanteninformationsverarbeitung, Albert-Einstein-Allee 11, D-89069 Ulm (Germany)], E-mail: stephan.schulz@uni-ulm.de
2008-04-15
Miniaturized ion trap arrays with many trap segments present a promising architecture for scalable quantum information processing. The miniaturization of segmented linear Paul traps allows partitioning the microtrap into different storage and processing zones. The individual position control of many ions-each of them carrying qubit information in its long-lived electronic levels-by the external trap control voltages is important for the implementation of next generation large-scale quantum algorithms. We present a novel scalable microchip multi-segmented ion trap with two different adjacent zones, one for the storage and another dedicated to the processing of quantum information using single ions and linear ion crystals. A pair of radio-frequency-driven electrodes and 62 independently controlled dc electrodes allows shuttling of single ions or linear ion crystals with numerically designed axial potentials at axial and radial trap frequencies of a few megahertz. We characterize and optimize the microtrap using sideband spectroscopy on the narrow S{sub 1/2}{r_reversible}D{sub 5/2} qubit transition of the {sup 40}Ca{sup +} ion, and demonstrate coherent single-qubit Rabi rotations and optical cooling methods. We determine the heating rate using sideband cooling measurements to the vibrational ground state, which is necessary for subsequent two-qubit quantum logic operations. The applicability for scalable quantum information processing is proved.
Paul Krugman : (presque un Nobel de géographie Paul Krugman: A Nobel Prize in geography?
Directory of Open Access Journals (Sweden)
Olivier Walther
2011-09-01
Full Text Available Paul Krugman a reçu le Prix Nobel d’économie pour son analyse des modèles du commerce mondial et de la localisation de l’activité économique. Voilà une nouvelle qui devrait réjouir certains géographes.Paul Krugman recently won Nobel Economics Prize for his work on trade patterns and location of economic activities. This sounds like good news for (some geographers.
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education. Paul S Follansbee. Articles written in Resonance – Journal of Science Education. Volume 11 Issue 6 June 2006 pp 8-25 General Article. Dr Smith goes to Los Alamos - Cyril Stanley Smith, Plutonium Metallurgy, and the Manhattan Project · Srivilliputhur G ...
International Nuclear Information System (INIS)
Waltz, R. E.; Candy, J.; Fahey, M.
2007-01-01
Electron temperature gradient (ETG) transport is conventionally defined as the electron energy transport at high wave number (high-k) where ions are adiabatic and there can be no ion energy or plasma transport. Previous gyrokinetic simulations have assumed adiabatic ions (ETG-ai) and work on the small electron gyroradius scale. However such ETG-ai simulations with trapped electrons often do not have well behaved nonlinear saturation unless fully kinetic ions (ki) and proper ion scale zonal flow modes are included. Electron energy transport is separated into ETG-ki at high-k and ion temperature gradient-trapped electron mode (ITG/TEM) at low-k. Expensive (more computer-intensive), high-resolution, large-ion-scale flux-tube simulations coupling ITG/TEM and ETG-ki turbulence are presented. These require a high effective Reynolds number R≡[k(max)/k(min)] 2 =μ 2 , where μ=[ρ si /ρ si ] is the ratio of ion to electron gyroradii. Compute times scale faster than μ 3 . By comparing the coupled expensive simulations with (1) much cheaper (less compute-intensive), uncoupled, high-resolution, small, flux-tube ETG-ki and with (2) uncoupled low-resolution, large, flux-tube ITG/TEM simulations, and also by artificially turning ''off'' the low-k or high-k drives, it appears that ITG/TEM and ETG-ki transport are not strongly coupled so long as ETG-ki can access some nonadiabatic ion scale zonal flows and both high-k and low-k are linearly unstable. However expensive coupled simulations are required for physically accurate k-spectra of the transport and turbulence. Simulations with μ≥30 appear to represent the physical range μ>40. ETG-ki transport measured in ion gyro-Bohm units is weakly dependent on μ. For the mid-radius core tokamak plasma parameters studied, ETG-ki is about 10% of the electron energy transport, which in turn is about 30% of the total energy transport (with negligible ExB shear). However at large ExB shear sufficient to quench the low-k ITG
Obituary: Paul Barr, 1955-2005
Parmar, Arvind
2007-12-01
Paul Barr, an extragalactic astronomer and spacecraft mission planner, died on 19 October 2005 at his home in Noordwijk, the Netherlands, at the age of 50. Although his scientific interests ranged from AGN to X-ray binaries, he will perhaps best be remembered for his mission planning skills on EXOSAT, ISO, and Integral. Many hundreds of observers have benefited from his ability to juggle seemingly impossible observing constraints and arrive at the optimum observing program. A rare talent. Barr was born in Sunderland, England, on 28 July 1995. After attending Saint Aidans Grammar School, where his father was the headmaster, he obtained his Bachelors Degree in astronomy from the University of London (June 1976) before moving to the Mullard Space Science Laboratory. There he obtained his Doctorate in X-ray astronomy in February 1980, using data from the Ariel V and Copernicus satellites. After a Post-Doctoral position at London University, where he did research into ultra-violet emission from AGN and X-ray binaries using IUE, Paul joined ESA in 1983. He worked on a wide range of missions including EXOSAT, ISO, and Integral. These observatories spanned the wavelength range from the Infra-red to the gamma-ray, giving insight into Paul's flexibility and ability to contribute in many areas. On ISO, Paul oversaw the scientific development and use of the very successful observation scheduling system — this topic became his specialty. As ISO operations became routine, he took up the challenge of space-borne gamma-ray astronomy and moved in 1997 to Integral where he worked in the Science Operation Centre (ISOC), at ESTEC in the Netherlands, as senior mission planner. He worked with the gamma-ray imager (IBIS) instrument team to ensure that operations of their instrument were properly supported by ESA and supported preparations of announcements of opportunity. In early 2005 the ISOC moved to Europe's Space Astronomy Centre (ESAC) just outside Madrid, Spain. Paul, however
Illusoorne autentsus / Toomas Paul
Paul, Toomas, 1939-
2000-01-01
Arvustus: Taylor, Charles. Autentsuse eetika / inglise k. tlk. Märt Väljataga. Tallinn : Hortus Litterarum, 2000. (Avatud Eesti raamat). Ilmunud ka kogumikus: Paul, Toomas. Kirik keset küla. Tartu : Ilmamaa, 2003, lk. 311-317
2000-01-01
28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ئ Marko Heinmäe, Hendrik Karm.
African Journals Online (AJOL)
Test
2011-06-07
Jun 7, 2011 ... The relationship between Saint Paul and the continent of Africa has never been a significant point of ... It consists of a constructive dialogue between a biblical original culture, .... John Walter Gregory to a continuous geological crack. (valley) of ...... As Stanley E. Porter concludes in his study on 2 Corinthians.
Directory of Open Access Journals (Sweden)
Eckhart Schnabel
2013-04-01
Full Text Available This Article is an attempt to shed light on a few texts of the acts of the Apostles and of the epistles which are viewed as sources documenting the life and activity of Saint Paul. The author attempts to settle a number of questions regarding the authenticity of sources illustrating the life of Saint Paul. Similar questions are often raised by those who write and publish guides and textbooks for the teaching of the Pauline corpus. The author agrees with the overwhelming positive judgment of the academic world regarding the authenticity of the pastoral epistles, but at the same time he notes a number of objections to their authenticity proposed by the same forum: inconsistencies within the vocabulary of the texts themselves, their linguistic style, and their theological argumentation. The author concludes that these objections are inconclusive and the features enumerated by those who object constitute in reality only minor exceptions, inconsequential when taking into account the entire Pauline corpus. The author also examines the authenticity and historical accuracy of the account of the life of Saint Paul as given in the Acts of the Apostles. A few Biblicists claim that the account in Acts is merely legendary and is to be regarded as a type of early Christian folklore. The author disagrees with this opinion, backing up his position with the evidence that both the Acts of the Apostles and the Pastoral Epistles agree in historical detail and background. The author concludes with a further consideration regarding the correct method guiding biblical research on Saint Paul. He opines that such research must view the biblical texts in a correct historical perspective
Vasks: Cantabile per archi, Paul Mägi / Bernhard Uske
Uske, Bernhard
1994-01-01
Uuest heliplaadist "Vasks: Cantabile per archi; Botschaft: Musica Dolorosa, Sinfonie für Streicher (Stimmen). Latvijas Nicionalais Simfoniskais Orkestris, Latvijas Filharmonijas Kamerorkestris. Pauls Megi [Paul Mägi]", Tovijs Lifsics. Wergo CD 6220-2
Paul Pinna avab Estonia Talveaias omanimelise baari / Christel Karits
Karits, Christel, 1966-
2006-01-01
Rahvusooper Estonia sajanda sünnipäeva puhul etendub 12. ja 13. septembril Estonia Talveaias lavastus "Paul Pinnat otsimas". Tekst on 95% osas Paul Pinna ja Karl August Hindrey sulest, dramatiseeris ja lavastas Heidi Sarapuu
Paul D. Sturkie: Avian cardiac physiologist.
Bello, Nicholas T; Cohick, Wendie S; McKeever, Kenneth H; Malinowski, Karyn
2018-06-01
Sturkie's Avian Physiology is a highly regarded textbook for the study of comparative poultry physiology. Less well known, however, is the contribution of Paul D. Sturkie (1909-2002) as a pioneer in the experimental physiology of avian species. His seminal research on the cardiovascular and hemodynamic controls of chickens and egg-laying hens had a notable impact on the poultry industry and breeding practices of farmers. The purpose of this article is to highlight the contributions and practical insights of Paul D. Sturkie to the field of poultry science.
Diffusion to finite-size traps
International Nuclear Information System (INIS)
Richards, P.M.
1986-01-01
The survival probability of a random-walking particle is derived for hopping in a random distribution of traps of arbitrary radius and concentration. The single-center approximation is shown to be valid for times of physical interest even when the fraction of volume occupied by traps approaches unity. The theory is based on computation of the number of different potential trap regions sampled in a random walk and is confirmed by simulations on a simple-cubic lattice
Major Additions to the Linus Pauling Canon
Davenport, Derek A.
2002-08-01
The National Library of Medicine has also just posted a Web site on Linus Pauling in its Profiles of Science series. While by no means as rich as the various Oregon State University sites, it is well worth visiting. There are texts of various speeches (including his Nobel address), many downloadable photographs, correspondence (including a poignant letter to James Watson and Francis Crick concerning their "rival" structures for DNA), and much else besides. There is a certain irony in Linus Pauling being honored by the National Library of Medicine. Ever since his 1949 presidential address to the American Chemical Society, and perhaps earlier, Pauling had been at loggerheads, sometimes acrimoniously so, with the medical establishment. It is easy to imagine him somewhere in the timeless infinitude of the empyrean sporting his characteristic ear-to-ear grin.
A Configurable Surface-Electrode Ion Trap Design for Quantum Information Processing
International Nuclear Information System (INIS)
Liu Wei; Chen Shu-Ming; Chen Ping-Xing; Wu Wei
2013-01-01
We propose a configurable surface-electrode ion trap design to alleviate the poor reusability of the existing traps. It can architecturally and electrically support 5 mainstream modes by design reuse, thus enhancing the trap reusability and reducing the experiment setup overhead. We also develop a corresponding simulation suite which can optimize trap geometries and calculate trap parameters to control the trapped ion's classic motion. According to our analytical and simulated results, the configurable design can serve as a unified platform for basic research of large-scale quantum information processing
Fluctuation theorem for an optically trapped tracer in dense colloids. A simulation study
Directory of Open Access Journals (Sweden)
Puertas Antonio M.
2013-03-01
Full Text Available The work supplied by an external parabolic potential that traps one tracer in a colloidal system is studied in this work by computer simulations. The density of the bath is changed from zero up to values close to the glass transition, and the velocity varies over several decades from the linear behaviour in the low Peclet limit to the high Peclet limit. The work distributions are analyzed using the model for the isolated Brownian partice, where the friction coefficient and temperature of the medium have been fitted to reproduce the position distribution of the tracer in the trap. The overall agreement is good but not perfect. The region of negative works is studied in more detail using the predictions of the fluctuation theorem, finding good qualitative agreement with the model of the isolated Brownian particle. The present results indicate that the fluctuation theorem is of application in cases where the tracer dynamics is complex, as predicted by theoretical works.
A 2D Array of 100's of Ions for Quantum Simulation and Many-Body Physics in a Penning Trap
Bohnet, Justin; Sawyer, Brian; Britton, Joseph; Bollinger, John
2015-05-01
Quantum simulations promise to reveal new materials and phenomena for experimental study, but few systems have demonstrated the capability to control ensembles in which quantum effects cannot be directly computed. One possible platform for intractable quantum simulations may be a system of 100's of 9Be+ ions in a Penning trap, where the valence electron spins are coupled with an effective Ising interaction in a 2D geometry. Here we report on results from a new Penning trap designed for 2D quantum simulations. We characterize the ion crystal stability and describe progress towards bench-marking quantum effects of the spin-spin coupling using a spin-squeezing witness. We also report on the successful photodissociation of BeH+ contaminant molecular ions that impede the use of such crystals for quantum simulation. This work lays the foundation for future experiments such as the observation of spin dynamics under the quantum Ising Hamiltonian with a transverse field. Supported by a NIST-NRC Research Associateship.
Ion trap architectures and new directions
Siverns, James D.; Quraishi, Qudsia
2017-12-01
Trapped ion technology has seen advances in performance, robustness and versatility over the last decade. With increasing numbers of trapped ion groups worldwide, a myriad of trap architectures are currently in use. Applications of trapped ions include: quantum simulation, computing and networking, time standards and fundamental studies in quantum dynamics. Design of such traps is driven by these various research aims, but some universally desirable properties have lead to the development of ion trap foundries. Additionally, the excellent control achievable with trapped ions and the ability to do photonic readout has allowed progress on quantum networking using entanglement between remotely situated ion-based nodes. Here, we present a selection of trap architectures currently in use by the community and present their most salient characteristics, identifying features particularly suited for quantum networking. We also discuss our own in-house research efforts aimed at long-distance trapped ion networking.
Energy Technology Data Exchange (ETDEWEB)
Santos, Ludovic; Vaeck, Nathalie [Laboratoire de Chimie Quantique et Photophysique, CP 160/09 Université Libre de Bruxelles, B-1050 Brussels (Belgium); Justum, Yves [Laboratoire de Chimie Physique, UMR 8000 and CNRS, Université Paris-Sud, F-91405 Orsay (France); Desouter-Lecomte, M. [Laboratoire de Chimie Physique, UMR 8000 and CNRS, Université Paris-Sud, F-91405 Orsay (France); Département de Chimie, Université de Liège, Bât B6c, Sart Tilman B-4000, Liège (Belgium)
2015-04-07
Following a recent proposal of L. Wang and D. Babikov [J. Chem. Phys. 137, 064301 (2012)], we theoretically illustrate the possibility of using the motional states of a Cd{sup +} ion trapped in a slightly anharmonic potential to simulate the single-particle time-dependent Schrödinger equation. The simulated wave packet is discretized on a spatial grid and the grid points are mapped on the ion motional states which define the qubit network. The localization probability at each grid point is obtained from the population in the corresponding motional state. The quantum gate is the elementary evolution operator corresponding to the time-dependent Schrödinger equation of the simulated system. The corresponding matrix can be estimated by any numerical algorithm. The radio-frequency field which is able to drive this unitary transformation among the qubit states of the ion is obtained by multi-target optimal control theory. The ion is assumed to be cooled in the ground motional state, and the preliminary step consists in initializing the qubits with the amplitudes of the initial simulated wave packet. The time evolution of the localization probability at the grids points is then obtained by successive applications of the gate and reading out the motional state population. The gate field is always identical for a given simulated potential, only the field preparing the initial wave packet has to be optimized for different simulations. We check the stability of the simulation against decoherence due to fluctuating electric fields in the trap electrodes by applying dissipative Lindblad dynamics.
Space-charge effects in Penning ion traps
Porobić, T.; Beck, M.; Breitenfeldt, M.; Couratin, C.; Finlay, P.; Knecht, A.; Fabian, X.; Friedag, P.; Fléchard, X.; Liénard, E.; Ban, G.; Zákoucký, D.; Soti, G.; Van Gorp, S.; Weinheimer, Ch.; Wursten, E.; Severijns, N.
2015-06-01
The influence of space-charge on ion cyclotron resonances and magnetron eigenfrequency in a gas-filled Penning ion trap has been investigated. Off-line measurements with K39+ using the cooling trap of the WITCH retardation spectrometer-based setup at ISOLDE/CERN were performed. Experimental ion cyclotron resonances were compared with ab initio Coulomb simulations and found to be in agreement. As an important systematic effect of the WITCH experiment, the magnetron eigenfrequency of the ion cloud was studied under increasing space-charge conditions. Finally, the helium buffer gas pressure in the Penning trap was determined by comparing experimental cooling rates with simulations.
Globaalne Paul Goble : " Lähituleviku suhtes olen pessimist" / Paul A. Goble ; interv. Teet Korsten
Goble, Paul Alan, 1949-
2004-01-01
Ilmunud ka: Severnoje Poberezhje, 18. sept. 2004, lk. 5. Kõrgetes USA valitsusametites teeninud sovetoloog Paul Goble, kes asus alaliselt elama Tartusse, räägib sidemetest Eestiga, huvist sovetoloogia vastu, endast. Vt. samas: 13 küsimust
Was Paul among the contemplatives?
Directory of Open Access Journals (Sweden)
James Panaggio
2016-09-01
Full Text Available This article offers a critique of the contemporary Contemplative Tradition’s view of spiritual transformation from the lens of the universally accepted letters of Paul. The article argues that contemporary contemplatives, especially Dallas Willard and Richard Foster, differ from Paul in three principle areas. Firstly, whereas Paul’s concept of transformation is based largely on objective realities, representatives of the Contemplative Tradition tend to focus on subjective realities. Secondly, contemporary contemplatives view transformation as coming as one imitates the life of Christ, his daily disciplines and activities, whereas Paul’s view centres on the death of Christ as foundational to the Christian’s identity and thus vital to the way they live out their faith. Finally, the cornerstone of the contemporary Contemplative Tradition’s view of spiritual transformation is the belief that the essential means by which transformation takes place is engagement in the spiritual disciplines. It is argued that many of the activities that are denominated as ‘spiritual disciplines’ are not in fact ‘transformative’ activities, and thus do not fit the category of spiritual disciplines. Furthermore, this study insists that Paul seldom links the practice of the disciplines with the means of transformation, offering instead five examples of specific means of transformation that flow out of Paul’s accepted letters.
Paul Krugman: välisvaluuta külge klammerdumine pole jätkusuutlik / Paul Krugman
Krugman, Paul, 1953-
2009-01-01
Valik 2008. aasta Nobeli majanduspreemia laureaadi Paul Krugmani vastuseid New Yorgi välisajakirjanike pressikeskuse briifingul "Kas depressioonimajandus tuleb tagasi?" esitatud Slovakkia, Lõuna-Aafrika, Austraalia ja Austria ajakirjanike küsimustele
Exhibition: Linus Pauling and the Twentieth Century
2003-01-01
On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opened at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for audience of all ages, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one...
Exhibition: Linus Pauling and the Twentieth Century
2003-01-01
On April 28 the exhibit Linus Pauling and the Twentieth Century organised by UNIDIR (United Nations Institute for Disarmament Research) and SGI (Soka Gakkai International) as well as with the contributions of CERN and the University of Geneva, opens at the United Nations Office of Geneva. Linus Pauling is the only person to date to have won two unshared Nobel Prizes: Chemistry in 1954 and Peace in 1962. The first was awarded for his landmark research on the nature of the chemical bond and its application in understanding the structure of complex substances. The second one acknowledged his courageous protest against atmospheric nuclear testing and his championship of international peace. The exhibit, for all ages' audiences, traces seven decades of Linus Pauling's life and influence on the 20th century. Before starting its European tour at the UNESCO headquarters in Paris, the exhibit opened in 1998 in San Francisco and then travelled within the United-States and to Japan with an attendance of more than one m...
Quantum optics including noise reduction, trapped ions, quantum trajectories, and decoherence
Orszag, Miguel
2016-01-01
This new edition gives a unique and broad coverage of basic laser-related phenomena that allow graduate students, scientists and engineers to carry out research in quantum optics and laser physics. It covers quantization of the electromagnetic field, quantum theory of coherence, atom-field interaction models, resonance fluorescence, quantum theory of damping, laser theory using both the master equation and the Langevin theory, the correlated emission laser, input-output theory with applications to non-linear optics, quantum trajectories, quantum non-demolition measurements and generation of non-classical vibrational states of ions in a Paul trap. In this third edition, there is an enlarged chapter on trapped ions, as well as new sections on quantum computing and quantum bits with applications. There is also additional material included for quantum processing and entanglement. These topics are presented in a unified and didactic manner, each chapter is accompanied by specific problems and hints to solutions to...
Simbuca, using a graphics card to simulate Coulomb interactions in a penning trap
Van Gorp, S; Friedag, P; De Leebeeck, V; Tandecki, M; Weinheimer, C; Breitenfeldt, M; Traykov, E; Severijn, N; Mader, J; Soti, G; Iitaka, T; Herlert, A; Wauters, F; Zakoucky, D; Kozlov, V; Roccia, S
2011-01-01
In almost all cases, N-body simulations are limited by the computation time available. Coulomb interaction calculations scale with O(N(2)) with N the number of particles. Approximation methods exist already to reduce the computation time to O(NlogN) although calculating the interaction still dominates the total simulation time. We present Simbuca, a simulation package for thousands of ions moving in a Penning trap which will be applied for the WITCH experiment. Simbuca uses the output of the Cunbody-1 library, which calculates the gravitational interaction between entities on a graphics card, and adapts it for Coulomb calculations. Furthermore the program incorporates three realistic buffer gas models, the possibility of importing realistic electric and magnetic fieldmaps and different order integrators with adaptive step size and error control. The software is released under the GNU General Public License and free for use. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
Hermeneutics in identity formation: Paul's use of Genesis in ...
African Journals Online (AJOL)
Paul's hermeneutics, in dealing with the scriptures and traditions of Israel and his concern for a specific identity for the communities he interacted with, require attention for the reciprocal, interrelationship between hermeneutics and identity in his letters. Paul's quotations from and allusions to the scriptures of Israel but also ...
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)
Simulation of the formation of antihydrogen in a nested Penning trap: effect of positron density
International Nuclear Information System (INIS)
Jonsell, S; Werf, D P van der; Charlton, M; Robicheaux, F
2009-01-01
Detailed simulations of antihydrogen formation have been performed under the conditions of the ATHENA experiment, using several densities of the positron plasma in the range n e = 5 x 10 13 m -3 to 10 15 m -3 . The simulations include only collisional effects, typically resulting in the formation of weakly bound antihydrogen via the three-body process, e + + e + + p-bar → H-bar + e + . (Radiative processes, which are much slower than collisional effects, are neglected.) The properties of these weakly bound anti-atoms are affected not only by further collisions in the plasma but also by the inherent electric fields. The role of field ionization in influencing the distribution of binding energies of the antihydrogen is clarified and the mechanism for this process in the strong B-field nested Penning trap used in the experiment is elucidated. The fate of antihydrogen is explained and the properties of the population detected after having reached the wall of the Penning trap electrodes, as well as those field ionized, are recorded. We find that the yield of detected antihydrogen varies with positron density roughly as n 1.7 e , rather than the n 2 e expected from the underlying formation process. As n e is increased, antihydrogen formation is sufficiently rapid that epithermal effects begin to play an important role. In general, the simulated timescales for antihydrogen formation are much shorter than those found from the experiment.
Hmong Political Involvement in St. Paul, Minnesota and Fresno, California
Directory of Open Access Journals (Sweden)
Yang Lor
2010-01-01
Full Text Available Over the past several years, Hmong in the United States have gained prominence for their increasing involvement in politics. Most of the attention has understandably focused on Fresno, California and St. Paul, Minnesota, home to the two largest Hmong populations in this country. While the Hmong communities in both cities are similar in size and have made significant political progress as evidenced by the election of Hmong candidates, the Hmong community in St. Paul has made greater inroads in the political realm. In addition to the elections of two Hmong candidates to the Minnesota State Legislature and two to the St. Paul School Board, the Hmong community in St. Paul has been able to engage local and state governments in Minnesotato address issues that affect the Hmong community. Through interviews, census data, and newspaper coverage of political campaigns, I show that Hmong in St. Paul have achieved greaterrepresentation in local and state governments and received greater support from government officials than Hmong in Fresno because Minnesota offers a social, economic, and politicalcontext that is favorable to fostering Hmong political involvement. Compared to Hmong in Fresno, Hmong in St. Paul have higher levels of socioeconomic resources and are more visible given their large size relative to other minority groups. They live in a region with consistently high levels of political participation and have political candidates who devote resources to mobilizing the Hmong community. Moreover, the Hmong vote has been critical to the success of Hmong candidates in St. Paul, an indication of the increasing political clout of the Hmong community there and a major reason why politicians in Minnesota are more willing to respond toissues that affect the Hmong community. Overall, this study highlights the importance of local and regional context in understanding the political incorporation of immigrants.
On social justice: Comparing Paul with Plato, Aristotle and the Stoics
Directory of Open Access Journals (Sweden)
Johan Strijdom
2007-05-01
Full Text Available n “In search of Paul” (2004 Crossan and Reed argue that Paul’s vision and program were essentially in continuity with Jesus’: both opposed, be it in Galilean villages or Roman cities, an unjust imperial system by means of an alternative project of egalitarian, distributive justice. Although Crossan elsewhere demonstrates the deep roots of this concern in the Jewish tradition, he tends to downplay the importance of Greek contributions in this regard. The purpose of this essay will be to offer, in constant dialogue with Crossan (and Reed, a more refined comparison of social justice in Paul on the one hand and Plato, Aristotle and the Stoics on the other. If Paul tried to establish egalitarian and sharing Christian communities under the Roman empire, how do this vision and program compare and contrast with Plato's hierarchical but communal concept of justice, Aristotle’s distributive notion according to merit, and most importantly the Stoics’ argument of “oikeiosis” (i.e., other-concern by concentrical familiarization with the other? Imagine, say Crossan and Reed (CR hereafter in their recent book on Paul, the following dialogue between ourselves and Paul: Do you think, Paul, that all men are created equal and endowed by their Creator with certain inalienable rights? I am not speaking about all men, but about all Christians. But do you think, Paul, that all people should be Christians? Yes, of course,. And do you think, Paul, that all Christians should be equal with one another?Yes, of course. Then do you think, Paul, that it is God’s will for all people to be equal with one another? Well, let me think about that one for a while and, in the meantime, you think about equality in Christ. (CR 2004:234
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1949 Honorary. Pauling, Prof. Linus Carl Nobel Laureate (Chemistry) - 1954; Peace - 1962. Date of birth: 28 February 1901. Date of death: 19 August 1994. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th ...
Magnetohydrodynamics and the earth's core selected works by Paul Roberts
Soward, Andrew M
2003-01-01
Paul Roberts'' research contributions are remarkable in their diversity, depth and international appeal. Papers from the Paul Roberts'' Anniversary meeting at the University of Exeter are presented in this volume. Topics include geomagnetism and dynamos, fluid mechanics and MHD, superfluidity, mixed phase regions, mean field electrodynamics and the Earth''s inner core. An incisive commentary of the papers puts the work of Paul Roberts into historical context. Magnetohydrodynamics and the Earth''s Core provides a valuable source of reference for graduates and researchers working in this area of geoscience.
International Nuclear Information System (INIS)
Cho, Joung-min; Akiyama, Yuto; Kakinuma, Tomoyuki; Mori, Takehiko
2013-01-01
We have investigated trap density of states (trap DOS) in n-channel organic field-effect transistors based on N,N ’-bis(cyclohexyl)naphthalene diimide (Cy-NDI) and dimethyldicyanoquinonediimine (DMDCNQI). A new method is proposed to extract trap DOS from the Arrhenius plot of the temperature-dependent transconductance. Double exponential trap DOS are observed, in which Cy-NDI has considerable deep states, by contrast, DMDCNQI has substantial tail states. In addition, numerical simulation of the transistor characteristics has been conducted by assuming an exponential trap distribution and the interface approximation. Temperature dependence of transfer characteristics are well reproduced only using several parameters, and the trap DOS obtained from the simulated characteristics are in good agreement with the assumed trap DOS, indicating that our analysis is self-consistent. Although the experimentally obtained Meyer-Neldel temperature is related to the trap distribution width, the simulation satisfies the Meyer-Neldel rule only very phenomenologically. The simulation also reveals that the subthreshold swing is not always a good indicator of the total trap amount, because it also largely depends on the trap distribution width. Finally, band transport is explored from the simulation having a small number of traps. A crossing point of the transfer curves and negative activation energy above a certain gate voltage are observed in the simulated characteristics, where the critical V G above which band transport is realized is determined by the sum of the trapped and free charge states below the conduction band edge
Kritik Nalar Hermeneutika Paul Ricoeur
Directory of Open Access Journals (Sweden)
Daden Robi Rahman
2016-03-01
Full Text Available Hermeneutics was born and developed in the West, specifically in response to the theological problem of Christianity, and always claimed to be an effective solution to the interpretation of Scripture. With existence of various schools, hermeneutics has also various shades and resulted different interpretations. Such as Schleiermacher, followed by Wilhelm Dilthey and Emilio Betti as initiators of hermeneutics methodology. Martin Heidegger and Gadamer followed with their ontological hermeneutics, and continued by Habermas with his critical hermeneutics. After that, the critical ontological hermeneutics initiated by either Paul Ricoeur, or Rudolf Bultman with his theological hermeneutics, and Derrida with his deconstructive hermeneutics. Among those schools, the writers interested in reviewing the hermeneutics of Paul Ricoeur which represents a distinctive theory of interpretation. His idea considered to be a bridge of the fierce debate between methodological traditions and philosophical traditions represented by Emilio Betti and Hans Georg Gadamer. The thought of Ricoeur was also claimed as a mediator between the positions of the romantic tradition of Schleiermacher and Dilthey with philosophy hermeneutic by Martin Heidegger. In another side, he was placed as a combination between the two great philosophical tradition, that’s German phenomenology and France structuralism. Furthermore, the thought of Ricoeur is a revision to the thought of Dilthey about explanation (erklären and understanding (verstehen. Through this paper, the writer will attempt to unravel the thought of Paul Ricoeur, and in the end, will clearly known the position of Ricoeur among other hermeneutics initiators.
Meandering Musings by Linus Pauling: "American Scientists and the Spirit of the Frontier".
Bause, George S
2016-04-01
Hoping to raise funds in 1975 for his namesake institute, Linus Pauling submitted to Esquire magazine a 32-page handwritten manuscript, "American Scientists and the Spirit of the Frontier." Angered when his submission for publication was declined, Pauling eventually gifted the original manuscript in 1986 to his friend, Linus Pauling Institute fundraiser Stephen Maddox, who would sell it in 2004 to the Wood Library-Museum of Anesthesiology. Published accurately here for the first time, the manuscript captures not only Pauling's sweeping metaphor of scientists as frontiersmen but also the creative process by which Pauling formulated his hydrate microcrystal theory of general anesthesia. Copyright © 2015 Elsevier Inc. All rights reserved.
Sodium hydride precipitation in sodium cold traps
International Nuclear Information System (INIS)
McPheeters, C.C.; Raue, D.J.
1979-10-01
A series of experiments have been performed to test a calculational model for precipitation of NaH in sodium cold traps. The calculational model, called ACTMODEL, is a computer simulation that uses the system geometry and operating conditions as input to calculate a mass transfer coefficient and the distribution of NaH in a cold trap. The ACTMODEL was tested using an analytical cold trap (ACT) that is simple and essentially one-dimensional. The ACT flow and temperature profile may be controlled at any desired condition. The ACT was analyzed destructively after each test to measure the actual NaH distribution. Excellent agreement was obtained between the ACTMODEL simulations and the experiments
An Experimental Analysis of Social Traps
Brechner, Kevin C.
1977-01-01
Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. Alaboratory analog was devised to simulate conditions that produce social traps. The intent was to cause an immediate positive…
Fueling profile sensitivities of trapped particle mode transport to TNS
International Nuclear Information System (INIS)
Mense, A.T.; Attenberger, S.E.; Houlberg, W.A.
1977-01-01
A key factor in the plasma thermal behavior is the anticipated existence of dissipative trapped particle modes. A possible scheme for controlling the strength of these modes was found. The scheme involves varying the cold fueling profile. A one dimensional multifluid transport code was used to simulate plasma behavior. A multiregime model for particle and energy transport was incorporated based on pseudoclassical, trapped electron, and trapped ion regimes used elsewhere in simulation of large tokamaks. Fueling profiles peaked toward the plasma edge may provide a means for reducing density-gradient-driven trapped particle modes, thus reducing diffusion and conduction losses
Paul Feyerabend: Science and the Anarchist.
Science, 1979
1979-01-01
Presents comments on the arguments of Paul Feyerabend toward progression science. The positions held by this philosopher of science are given with accompanying remarks from other philosophers and historians. (SA)
Eestis meenutati Paul Kerest / Kalev Vilgats
Vilgats, Kalev
2011-01-01
Paul Kerese 95. sünniaastapäeva puhul viibisid Tallinnas male eksmaailmameister Anatoli Karpov ja teised malemaailma tipud. President Toomas Hendrik Ilves kohtus male suurkujudega Kadriorus 6. jaan. 2011
Sodium hydride precipitation in sodium cold traps
International Nuclear Information System (INIS)
McPheeters, C.C.; Raue, D.J.
1980-06-01
A series of experiments have been performed to test a calculational model for precipitation of NaH in sodium cold traps. The calculational model, called ACTMODEL, is a computer simulation that uses the system geometry and operating conditions as input to calculate a mass-transfer coefficient and the distribution of NaH in a cold trap. The ACTMODEL was tested using an analytical cold trap (ACT) that is simple and essentially one-dimensional. The ACT flow and temperature profile can be controlled at any desired condition. The ACT was analyzed destructively after each test to measure the actual NaH distribution. Excellent agreement was obtained between the ACTMODEL simulations and the experiments. Mass-transfer coefficients ranging upward from 6 x 10 -5 m/s were measured in both packless and packed traps. As much as a fourfold increase in precipitation surface area was observed with increasing amount of NaH deposited. 11 figures, 2 tables
Reframing Paul's sibling language in light of Jewish epistolary forms ...
African Journals Online (AJOL)
However, Jewish dimensions (particularly ethnic dimensions) of Paul's sibling language still remain unexplored in current scholarship. Furthermore, scholars have not drawn much attention to how Jewish letter writers use sibling terms in their letters. This article offers a new interpretation on Paul's sibling language in light of ...
Magnetic trapping of Rydberg atoms
Niestadt, D.; Naber, J.; Kokkelmans, S.J.J.M.F.; Spreeuw, R.J.C.
2016-01-01
Magnetic trapping is a well-established technique for ground state atoms. We seek to extend this concept to Rydberg atoms. Rydberg atoms are important for current visions of quantum simulators that will be used in the near future to simulate and analyse quantum problems. Current efforts in Amsterdam
Quantum Simulation of the Quantum Rabi Model in a Trapped Ion
Lv, Dingshun; An, Shuoming; Liu, Zhenyu; Zhang, Jing-Ning; Pedernales, Julen S.; Lamata, Lucas; Solano, Enrique; Kim, Kihwan
2018-04-01
The quantum Rabi model, involving a two-level system and a bosonic field mode, is arguably the simplest and most fundamental model describing quantum light-matter interactions. Historically, due to the restricted parameter regimes of natural light-matter processes, the richness of this model has been elusive in the lab. Here, we experimentally realize a quantum simulation of the quantum Rabi model in a single trapped ion, where the coupling strength between the simulated light mode and atom can be tuned at will. The versatility of the demonstrated quantum simulator enables us to experimentally explore the quantum Rabi model in detail, including a wide range of otherwise unaccessible phenomena, as those happening in the ultrastrong and deep strong-coupling regimes. In this sense, we are able to adiabatically generate the ground state of the quantum Rabi model in the deep strong-coupling regime, where we are able to detect the nontrivial entanglement between the bosonic field mode and the two-level system. Moreover, we observe the breakdown of the rotating-wave approximation when the coupling strength is increased, and the generation of phonon wave packets that bounce back and forth when the coupling reaches the deep strong-coupling regime. Finally, we also measure the energy spectrum of the quantum Rabi model in the ultrastrong-coupling regime.
Quantum Simulation of the Quantum Rabi Model in a Trapped Ion
Directory of Open Access Journals (Sweden)
Dingshun Lv
2018-04-01
Full Text Available The quantum Rabi model, involving a two-level system and a bosonic field mode, is arguably the simplest and most fundamental model describing quantum light-matter interactions. Historically, due to the restricted parameter regimes of natural light-matter processes, the richness of this model has been elusive in the lab. Here, we experimentally realize a quantum simulation of the quantum Rabi model in a single trapped ion, where the coupling strength between the simulated light mode and atom can be tuned at will. The versatility of the demonstrated quantum simulator enables us to experimentally explore the quantum Rabi model in detail, including a wide range of otherwise unaccessible phenomena, as those happening in the ultrastrong and deep strong-coupling regimes. In this sense, we are able to adiabatically generate the ground state of the quantum Rabi model in the deep strong-coupling regime, where we are able to detect the nontrivial entanglement between the bosonic field mode and the two-level system. Moreover, we observe the breakdown of the rotating-wave approximation when the coupling strength is increased, and the generation of phonon wave packets that bounce back and forth when the coupling reaches the deep strong-coupling regime. Finally, we also measure the energy spectrum of the quantum Rabi model in the ultrastrong-coupling regime.
Numerical simulation of injection and resistive trapping of ion rings
International Nuclear Information System (INIS)
Mankofsky, A.; Friedman, A.; Sudan, R.N.
1981-01-01
Numerical studies of the injection and resistive trapping efficiency of ion rings, using an improved algorithm are presented. Trapping efficiency is found to be strongly dependent upon the number of particles injected and upon mirror ratios in the system. Wall resistivity and beam divergence affect the process to a lesser extent. (author)
On-chip particle trapping and manipulation
Leake, Kaelyn Danielle
The ability to control and manipulate the world around us is human nature. Humans and our ancestors have used tools for millions of years. Only in recent years have we been able to control objects at such small levels. In order to understand the world around us it is frequently necessary to interact with the biological world. Optical trapping and manipulation offer a non-invasive way to move, sort and interact with particles and cells to see how they react to the world around them. Optical tweezers are ideal in their abilities but they require large, non-portable, and expensive setups limiting how and where we can use them. A cheap portable platform is required in order to have optical manipulation reach its full potential. On-chip technology offers a great solution to this challenge. We focused on the Liquid-Core Anti-Resonant Reflecting Optical Waveguide (liquid-core ARROW) for our work. The ARROW is an ideal platform, which has anti-resonant layers which allow light to be guided in liquids, allowing for particles to easily be manipulated. It is manufactured using standard silicon manufacturing techniques making it easy to produce. The planner design makes it easy to integrate with other technologies. Initially I worked to improve the ARROW chip by reducing the intersection losses and by reducing the fluorescence and background on the ARROW chip. The ARROW chip has already been used to trap and push particles along its channel but here I introduce several new methods of particle trapping and manipulation on the ARROW chip. Traditional two beam traps use two counter propagating beams. A trapping scheme that uses two orthogonal beams which counter to first instinct allow for trapping at their intersection is introduced. This scheme is thoroughly predicted and analyzed using realistic conditions. Simulations of this method were done using a program which looks at both the fluidics and optical sources to model complex situations. These simulations were also used to
Andresen, G B; Bray, C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Gill, D R; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jørgensen, L V; Kerrigan, S J; Keller, J; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki, Y
2009-01-01
In many antihydrogen trapping schemes, antiprotons held in a short-well Penning–Malmberg trap are released into a longer well. This process necessarily causes the bounce-averaged rotation frequency $\\overline{\\Omega}_r$ of the antiprotons around the trap axis to pass through zero. In the presence of a transverse magnetic multipole, experiments and simulations show that many antiprotons (over 30% in some cases) can be lost to a hitherto unidentified bounce-resonant process when $\\overline{\\Omega}_r$ is close to zero.
2012-01-01
It is with great sorrow that we announce the sudden passing of our former colleague and friend, Paul Bouchardy, on Friday 17 February. An outstanding travel agent, well-respected and active within his profession (he was in charge of apprenticeships for the Association of Geneva Travel Agencies - AGAV), Paul was director of the Carlson Wagonlit agency at CERN for many years. He knew the world like the back of his hand, and many people have benefited from his vast knowledge and expert tourist advice. Key figure in the Laboratory since the 1970’s, he retired in 2002 after 38 years with Carlson Wagonlit, including more than 30 years of on-site service to the CERN community. In these difficult days, our thoughts are with his wife and children and grandchildren, the family he cherished above all else and who accompanied him until embarking on his final journey. His friends and former colleagues at CERN
Neutron radiography at the Paul Scherrer Institute
International Nuclear Information System (INIS)
Pleinert, H.; Lehmann, E.; Hammer, J.
1994-01-01
Neutron radiography provides an efficient tool of measurement for many applications in fundamental research as well as in industrial non-destructive testing (NDT). A neutron radiography program has been initiated at the Paul Scherrer Institute and implemented since 1992. From the beginning of 1992 until the end of 1993, a neutron facility has been in operation at the SAPHIR research reactor. Several applications have been tested and programs on two main fields of application have been established, focusing on the study of porous materials, especially concrete and granitic rock. The investigations on concrete and other building materials are carried out in cooperation with the Swiss Federal Institute of Technology in Zurich. The experimental activities are currently carried out at the Atominstitute of the Austrian Universities in Vienna, in the framework of a cooperation program with the Atominstitute. The continuation of the activities on a new radiography facility at the spallation source SINQ is planned at the Paul Scherrer Institute. In the following an overview of the method, of the actual and potential applications of neutron radiography at the Paul Scherrer Institute is given. (author) 6 figs., 1 tab., 3 refs
Optical Forces on Non-Spherical Nanoparticles Trapped by Optical Waveguides
Hasan Ahmed, Dewan; Sung, Hyung Jin
2011-07-01
Numerical simulations of a solid-core polymer waveguide structure were performed to calculate the trapping efficiencies of particles with nanoscale dimensions smaller than the wavelength of the trapping beam. A three-dimensional (3-D) finite element method was employed to calculate the electromagnetic field. The inlet and outlet boundary conditions were obtained using an eigenvalue solver to determine the guided and evanescent mode profiles. The Maxwell stress tensor was considered for the calculation of the transverse and downward trapping efficiencies. A particle at the center of the waveguide showed minimal transverse trapping efficiency and maximal downward trapping efficiency. This trend gradually reversed as the particle moved away from the center of the waveguide. Particles with larger surface areas exhibited higher trapping efficiencies and tended to be trapped near the waveguide. Particles displaced from the wave input tended to be trapped at the waveguide surface. Simulation of an ellipsoidal particle showed that the orientation of the major axis along the waveguide's lateral z-coordinate significantly influenced the trapping efficiency. The particle dimensions along the z-coordinate were more critical than the gap distance (vertical displacement from the floor of the waveguide) between the ellipsoid particle and the waveguide. The present model was validated using the available results reported in the literature for different trapping efficiencies.
Interview med professor Paul du Gay om bureaukratiets værdi
DEFF Research Database (Denmark)
Pors, Anja Svejgaard
2013-01-01
Paul du Gay er sociolog og globaliseringsprofessor ved Institut for Organisation på Copenhagen Business School. I hans forskning interesserer han sig blandt andet for bureaukratiet som styreform. Gennem årtier har bureaukratiet været genstand for omfattende kritik for dets langsommelighed......, inhumanitet og manglende fleksibilitet. Paul du Gay har taget til genmæle og forsvarer bureaukratiet som en styreform, der understøtter demokrati. I arbejdet med administration som praksis og faglighed har vi interviewet Paul du Gay om nogle af de centrale pointer i denne forskning. Samtalen kredser om...
Notes on Paul Kuimet / Pille Epner
Epner, Pille
2011-01-01
Fotograaf Paul Kuimetist, tema loomingust, Tallinnas Hobusepea galeriis toimunud isikunäitusest "In Vicinity" (2010), mis uuris valglinnastumist, kohaspetsiifilisest installatsioonist "Untitled" (2010) ja näitusest "Not Necessarily So" (koos Laura Tootsiga, 2010) Linzis
International Nuclear Information System (INIS)
Charles Doret, S; Amini, Jason M; Wright, Kenneth; Volin, Curtis; Killian, Tyler; Ozakin, Arkadas; Denison, Douglas; Hayden, Harley; Pai, C-S; Slusher, Richart E; Harter, Alexa W
2012-01-01
Recent advances in quantum information processing with trapped ions have demonstrated the need for new ion trap architectures capable of holding and manipulating chains of many (>10) ions. Here we present the design and detailed characterization of a new linear trap, microfabricated with scalable complementary metal-oxide-semiconductor (CMOS) techniques, that is well-suited to this challenge. Forty-four individually controlled dc electrodes provide the many degrees of freedom required to construct anharmonic potential wells, shuttle ions, merge and split ion chains, precisely tune secular mode frequencies, and adjust the orientation of trap axes. Microfabricated capacitors on dc electrodes suppress radio-frequency pickup and excess micromotion, while a top-level ground layer simplifies modeling of electric fields and protects trap structures underneath. A localized aperture in the substrate provides access to the trapping region from an oven below, permitting deterministic loading of particular isotopic/elemental sequences via species-selective photoionization. The shapes of the aperture and radio-frequency electrodes are optimized to minimize perturbation of the trapping pseudopotential. Laboratory experiments verify simulated potentials and characterize trapping lifetimes, stray electric fields, and ion heating rates, while measurement and cancellation of spatially-varying stray electric fields permits the formation of nearly-equally spaced ion chains. (paper)
Paul Dundes Wolfowitz. Aukus sokkidega pistrik nõelub mainet / Arko Olesk
Olesk, Arko, 1981-
2007-01-01
Maailmapanga president Paul Wolfowitz teatas pressikonverentsil, et soovib tööd jätkata. Paul Wolfowitzi karjäärist, päritolust, eraelust ja usalduse kaotamisest korruptsioonihõngulise loo pärast oma sõbratarile Shaha Ali Rizale palgatõusu nõudmisel
Optical system for trapping particles in air.
Kampmann, R; Chall, A K; Kleindienst, R; Sinzinger, S
2014-02-01
An innovative optical system for trapping particles in air is presented. We demonstrate an optical system specifically optimized for high precision positioning of objects with a size of several micrometers within a nanopositioning and nanomeasuring machine (NPMM). Based on a specification sheet, an initial system design was calculated and optimized in an iterative design process. By combining optical design software with optical force simulation tools, a highly efficient optical system was developed. Both components of the system, which include a refractive double axicon and a parabolic ring mirror, were fabricated by ultra-precision turning. The characterization of the optical elements and the whole system, especially the force simulations based on caustic measurements, represent an important interim result for the subsequently performed trapping experiments. The caustic of the trapping beam produced by the system was visualized with the help of image processing techniques. Finally, we demonstrated the unique efficiency of the configuration by reproducibly trapping fused silica spheres with a diameter of 10 μm at a distance of 2.05 mm from the final optical surface.
Control of the conformations of ion Coulomb crystals in a Penning trap
Mavadia, Sandeep; Goodwin, Joseph F.; Stutter, Graham; Bharadia, Shailen; Crick, Daniel R.; Segal, Daniel M.; Thompson, Richard C.
2013-01-01
Laser-cooled atomic ions form ordered structures in radiofrequency ion traps and in Penning traps. Here we demonstrate in a Penning trap the creation and manipulation of a wide variety of ion Coulomb crystals formed from small numbers of ions. The configuration can be changed from a linear string, through intermediate geometries, to a planar structure. The transition from a linear string to a zigzag geometry is observed for the first time in a Penning trap. The conformations of the crystals are set by the applied trap potential and the laser parameters, and agree with simulations. These simulations indicate that the rotation frequency of a small crystal is mainly determined by the laser parameters, independent of the number of ions and the axial confinement strength. This system has potential applications for quantum simulation, quantum information processing and tests of fundamental physics models from quantum field theory to cosmology. PMID:24096901
CrossRef Space-charge effects in Penning ion traps
Porobić, T; Breitenfeldt, M; Couratin, C; Finlay, P; Knecht, A; Fabian, X; Friedag, P; Fléchard, X; Liénard, E; Ban, G; Zákoucký, D; Soti, G; Van Gorp, S; Weinheimer, Ch; Wursten, E; Severijns, N
2015-01-01
The influence of space-charge on ion cyclotron resonances and magnetron eigenfrequency in a gas-filled Penning ion trap has been investigated. Off-line measurements with View the MathML source using the cooling trap of the WITCH retardation spectrometer-based setup at ISOLDE/CERN were performed. Experimental ion cyclotron resonances were compared with ab initio Coulomb simulations and found to be in agreement. As an important systematic effect of the WITCH experiment, the magnetron eigenfrequency of the ion cloud was studied under increasing space-charge conditions. Finally, the helium buffer gas pressure in the Penning trap was determined by comparing experimental cooling rates with simulations.
Dirac, Prof. Paul Adrien Maurice
Indian Academy of Sciences (India)
Home; Fellowship. Fellow Profile. Elected: 1935 Honorary. Dirac, Prof. Paul Adrien Maurice Nobel Laureate (Physics) - 1933. Date of birth: 8 August 1902. Date of death: 20 October 1984. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...
Paul Henning Krogh on Soil Ecotoxicology
DEFF Research Database (Denmark)
Krogh, Paul Henning
2008-01-01
In a recent analysis of data from Essential Science Indicators SM from Thomson Reuters , Dr. Paul Henning Krogh was named a Rising Star in the field of Environment & Ecology. His current record in this field includes 48 papers cited a total of 410 times. Dr. Krogh is a Senior Scientist in the Dep......In a recent analysis of data from Essential Science Indicators SM from Thomson Reuters , Dr. Paul Henning Krogh was named a Rising Star in the field of Environment & Ecology. His current record in this field includes 48 papers cited a total of 410 times. Dr. Krogh is a Senior Scientist...... in the Department of Terrestrial Ecology at the National Environmental Research Institute, part of the University of Aarhus in Silkeborg, Denmark. This month, he talks with ScienceWatch.com correspondent Simon Mitton about his highly cited work. View Article...
Dabbabi, Samar; Ben Nasr, Tarek; Turki Kamoun, Najoua
2018-02-01
Numerical simulation is carried out using the Silvaco ATLAS software to predict the effect of 1-MeV electron and 4-MeV proton irradiation on the performance of a Cu(In, Ga)Se2 (CIGS) solar cell that operates under the air mass zero spectrum (AM0). As a consequence of irradiation, two types of traps are induced including the donor- and acceptor-type traps. Only one of them (the donor-type trap) is found responsible for the degradation of the open-circuit voltage (V OC), fill factor (FF) and efficiency (η), while the short circuit current (J SC) remains essentially unaffected. The modelling simulation validity is verified by comparison with the experimental data. This article shows that CIGS solar cells are suited for space applications.
Meier, Monika
2007-01-01
The German writerJean Paul (Johann Paul Friedrich Richter, 1763-1825) and his friendJohann Bernhard Hermann (1761-1790) became acquainted with the thoughts of late Enlightenment at the University of Leipzig. They particularly appreciated the anthropology of Ernst Platner, who taught philosophy and aesthetics as well as medicine. Their confidential correspondence contains reflections on their respective situation and well being. Both write about feeling ill and label their illness "hypochondria". In the course of the correspondence Jean Paul's understanding of hypochondria evolves from an illness of the entrails as he follows Hermann, who supports the modern concept of hypochondria as an illness of the nerves. Two important themes from this correspondence recur in Jean Paul's novels and tales: firstly, his way of expressing comfort is related to his aesthetics, and secondly, the satirical way of portraying at least certain aspects of illness as imaginary reappears in his first successful novel "The Invisible Lodge" (1793).
2012-01-01
We were greatly saddened to learn of the sudden death of Dr Jean-Paul Diss at his home on 7 June 2012. Jean-Paul studied medicine at the Strasbourg Faculty of Medicine and began his career as an occupational medical practitioner at the Mulhouse potash mines. He then came to CERN in 1965 to set up a Medical Service at the request of the then CERN Director-General, Professor Weisskopf. He was the first person to hold the position of Head of the Medical Service and he invested all his energies to provide the Organization with an occupational healthcare unit worthy of the name. As a pioneer of occupational medicine, he worked tirelessly to improve the working conditions of the members of the personnel and continued to be solicitous about the health of every member of the personnel until his retirement in 1993. Over the past twenty years, he remained active within the CERN Pensioners Association, in particular as the pensioners’ representative on the CERN Health Insuran...
77 FR 68149 - Karen Paul Holley, M.D.; Decision and Order
2012-11-15
... DEPARTMENT OF JUSTICE Drug Enforcement Administration [Docket No. 12-51] Karen Paul Holley, M.D... revoke the DEA Certificate of Registration (COR), Number BH8988339, of Karen Paul Holley, M.D....D., 74 FR 17528, 174529 (2009); John B. Freitas, D.O., 74 FR 17524, 17525 (2009); Roger A. Rodriguez...
"Paul Revere's Ride": Awakening Abolitionists
Lepore, Jill
2011-01-01
Henry Wadsworth Longfellow used to be both the best-known poet in the English-speaking world and the most beloved, adored by the learned and the lowly alike, read by everyone from Nathaniel Hawthorne and Abraham Lincoln to John Ruskin and Queen Victoria--and, just as avidly, by the queen's servants. "Paul Revere's Ride" is Longfellow's best-known…
Contesting history and identity formation in Paul and in South Africa ...
African Journals Online (AJOL)
This study compares dynamics in the contestation of history and identity between Paul to post-1994 white Afrikaners in South Africa. In reference to Paul, I am interested in how the followers of the nascent Hellenistic Gentile Christian movement claimed legitimacy as the true Jews, usurping the monopoly of the identity 'true ...
On social justice: Comparing Paul with Plato, Aristotle and the Stoics
African Journals Online (AJOL)
p1243322
If Paul tried to establish egalitarian and sharing Christian communities under ... study on Paul for the debate on universal human values – except to suggest ... challenge until, at least for many, Caesar's apotheosis meant not ... just the promise, but the start of the world's salvation, redemption, ..... All will be on a par together.
A DOCUMENT PAUL AUSTER’S NEW YORK TRILOGY
Directory of Open Access Journals (Sweden)
Natalia N. Smirnova
2017-03-01
Full Text Available The article deals with the way a literary work “creates” a document out of itself, on the example of Paul Auster’s novels. A document here is the report of a character, a private detective who is watching another character (a writer but also the book of a fictional writer who is writing a story of the detective who is watching him, and eventually the book about this whole story. In this case, the search for the other, watching him, is inevitably associated with the search for oneself, self-observation. Biography becomes autobiography, e.g. a document rather than a narrative based on a document. This story becomes projected on the story of Don Quixote (of which “some” Paul Auster, a fictional writer, is writing an essay. The Other is a landmark in the vast desert of fictional worlds where Paul Auster’s Don Quixote wanders alongside other characters of the trilogy. The author may not return from his endless journey through imaginary worlds; his life does not belong to either real life or fiction. He gives life to his characters while remaining invisible himself. Paul Auster’s The New York Trilogy explores such existential situation where the only evidence of the author’s life is a document left by his character. The author leaves a documentary record of a kind about his own existence. It this sense, literature is a document of life and of the endless search for a reason to the existence of an individual who, being not equal to him- or herself, is always the other and never a type or a template.
A radio frequency quadrupole ion beam buncher for ISOLTRAP
Bollen, G; Dezfuli, A M G; Henry, S; Herfurth, F; Kellerbauer, A G; Kim, T; Kluge, H J; Kohl, A; Lamour, E; Lunney, M D; Moore, R B; Quint, W; Schwarz, S; Varfalvy, P; Vermeeren, L
1998-01-01
ISOLTRAP is a Penning trap spectrometer at the on-line mass separator ISOLDE at CERN for the mass determination of radioisotopes. It consists of three electromagnetic traps in tandem; a Paul trap for ISOLDE beam collection, a Penning trap for cooling and purification and a high-precision Penning trap for the measurement of masses by cyclotron resonance. The Paul trap, which collects radionuclide ions using only electric fields and a noble buffer gas, has been essential for the masses of radionuclides that cannot be surface ionized. The success with this system has led to the present program to increase the collection efficiency by replacing the Paul trap by a radiofrequency quadrupole ion guide operating as a buncher. This system would also provide a DC ISOLDE beam of emittance approaching 1$\\pi$ -mm-mrad. (3 refs).
Comparing simulation of plasma turbulence with experiment
International Nuclear Information System (INIS)
Ross, David W.; Bravenec, Ronald V.; Dorland, William; Beer, Michael A.; Hammett, G. W.; McKee, George R.; Fonck, Raymond J.; Murakami, Masanori; Burrell, Keith H.; Jackson, Gary L.; Staebler, Gary M.
2002-01-01
The direct quantitative correspondence between theoretical predictions and the measured plasma fluctuations and transport is tested by performing nonlinear gyro-Landau-fluid simulations with the GRYFFIN (or ITG) code [W. Dorland and G. W. Hammett, Phys. Fluids B 5, 812 (1993); M. A. Beer and G. W. Hammett, Phys. Plasmas 3, 4046 (1996)]. In an L-mode reference discharge in the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)], which has relatively large fluctuations and transport, the turbulence is dominated by ion temperature gradient (ITG) modes. Trapped electron modes and impurity drift waves also play a role. Density fluctuations are measured by beam emission spectroscopy [R. J. Fonck, P. A. Duperrex, and S. F. Paul, Rev. Sci. Instrum. 61, 3487 (1990)]. Experimental fluxes and corresponding diffusivities are analyzed by the TRANSP code [R. J. Hawryluk, in Physics of Plasmas Close to Thermonuclear Conditions, edited by B. Coppi, G. G. Leotta, D. Pfirsch, R. Pozzoli, and E. Sindoni (Pergamon, Oxford, 1980), Vol. 1, p. 19]. The shape of the simulated wave number spectrum is close to the measured one. The simulated ion thermal transport, corrected for ExB low shear, exceeds the experimental value by a factor of 1.5 to 2.0. The simulation overestimates the density fluctuation level by an even larger factor. On the other hand, the simulation underestimates the electron thermal transport, which may be accounted for by modes that are not accessible to the simulation or to the BES measurement
Thermal and hydraulic analyses of the System 81 cold traps
Energy Technology Data Exchange (ETDEWEB)
Kim, K.
1977-06-15
Thermal and hydraulic analyses of the System 81 Type I and II cold traps were completed except for thermal transients analysis. Results are evaluated, discussed, and reported. Analytical models were developed to determine the physical dimensions of the cold traps and to predict the performance. The FFTF cold trap crystallizer performances were simulated using the thermal model. This simulation shows that the analytical model developed predicts reasonably conservative temperatures. Pressure drop and sodium residence time calculations indicate that the present design will meet the requirements specified in the E-Specification. Steady state temperature data for the critical regions were generated to assess the magnitude of the thermal stress.
Location - Managed Facility - St. Paul District (MVP)
Army Corps of Engineers, Department of the Army, Department of Defense — St. Paul District - US Army Corps of Engineers Managed Facility locations. District headquarters, Natural Resource, Recreation, Lock and Dam, and Regulatory offices...
Experiments with trapped ions and ultrafast laser pulses
Johnson, Kale Gifford
Since the dawn of quantum information science, laser-cooled trapped atomic ions have been one of the most compelling systems for the physical realization of a quantum computer. By applying qubit state dependent forces to the ions, their collective motional modes can be used as a bus to realize entangling quantum gates. Ultrafast state-dependent kicks [1] can provide a universal set of quantum logic operations, in conjunction with ultrafast single qubit rotations [2], which uses only ultrafast laser pulses. This may present a clearer route to scaling a trapped ion processor [3]. In addition to the role that spin-dependent kicks (SDKs) play in quantum computation, their utility in fundamental quantum mechanics research is also apparent. In this thesis, we present a set of experiments which demonstrate some of the principle properties of SDKs including ion motion independence (we demonstrate single ion thermometry from the ground state to near room temperature and the largest Schrodinger cat state ever created in an oscillator), high speed operations (compared with conventional atom-laser interactions), and multi-qubit entanglement operations with speed that is not fundamentally limited by the trap oscillation frequency. We also present a method to provide higher stability in the radial mode ion oscillation frequencies of a linear radiofrequency (rf) Paul trap-a crucial factor when performing operations on the rf-sensitive modes. Finally, we present the highest atomic position sensitivity measurement of an isolated atom to date of 0.5 nm Hz. (-1/2) with a minimum uncertaintyof 1.7 nm using a 0.6 numerical aperature (NA) lens system, along with a method to correct aberrations and a direct position measurement of ion micromotion (the inherent oscillations of an ion trapped in an oscillating rf field). This development could be used to directly image atom motion in the quantum regime, along with sensing forces at the yoctonewton [10. (-24) N)] scale forgravity sensing
Development of flood-inundation maps for the Mississippi River in Saint Paul, Minnesota
Czuba, Christiana R.; Fallon, James D.; Lewis, Corby R.; Cooper, Diane F.
2014-01-01
Digital flood-inundation maps for a 6.3-mile reach of the Mississippi River in Saint Paul, Minnesota, were developed through a multi-agency effort by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers and in collaboration with the National Weather Service. The inundation maps, which can be accessed through the U.S. Geological Survey Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ and the National Weather Service Advanced Hydrologic Prediction Service site at http://water.weather.gov/ahps/inundation.php, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the U.S. Geological Survey streamgage at the Mississippi River at Saint Paul (05331000). The National Weather Service forecasted peak-stage information at the streamgage may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the Mississippi River by means of a one-dimensional step-backwater model. The hydraulic model was calibrated using the most recent stage-discharge relation at the Robert Street location (rating curve number 38.0) of the Mississippi River at Saint Paul (streamgage 05331000), as well as an approximate water-surface elevation-discharge relation at the Mississippi River at South Saint Paul (U.S. Army Corps of Engineers streamgage SSPM5). The model also was verified against observed high-water marks from the recent 2011 flood event and the water-surface profile from existing flood insurance studies. The hydraulic model was then used to determine 25 water-surface profiles for flood stages at 1-foot intervals ranging from approximately bankfull stage to greater than the highest recorded stage at streamgage 05331000. The simulated water-surface profiles were then combined with a geographic information system digital elevation model, derived from high-resolution topography
Ion trap simulations of quantum fields in an expanding universe.
Alsing, Paul M; Dowling, Jonathan P; Milburn, G J
2005-06-10
We propose an experiment in which the phonon excitation of ion(s) in a trap, with a trap frequency exponentially modulated at rate kappa, exhibits a thermal spectrum with an "Unruh" temperature given by k(B)T=Planck kappa. We discuss the similarities of this experiment to the response of detectors in a de Sitter universe and the usual Unruh effect for uniformly accelerated detectors. We demonstrate a new Unruh effect for detectors that respond to antinormally ordered moments using the ion's first blue sideband transition.
Many-body quantum simulation with Rydberg atoms and ions
International Nuclear Information System (INIS)
Mueller, M.
2010-01-01
This thesis presents my work that is located at the interface between the fields of atomic physics, quantum optics and quantum information. The work was performed at the Institute of Theoretical Physics of the University of Innsbruck and the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences under the supervision of Prof. Peter Zoller. The main topic of this thesis is the investigation of new schemes for quantum simulation of interacting many-body systems. The thesis is divided into three parts, which cover my work on i) chains of trapped Rydberg ions ii) quantum information processing and simulation with Rydberg atoms and iii) quantum simulation with ground state ions. The first part of this thesis is concerned with the study of Rydberg ions trapped in a linear Paul trap. The properties of ionic Rydberg states in the presence of the static and time-dependent electric trapping fields are investigated. First it is analyzed under which conditions laser-excited Rydberg ions can be trapped in a stable configuration. Furthermore, it is shown that strong dipole-dipole interactions among the ions can be achieved by microwave dressing fields. These interactions can give rise to dynamics of Rydberg excitations through the ion crystal, which take place on a nanosecond timescale and can be described by effective spin-models. In addition, it is discussed how to achieve fast two-qubit entangling gates between pairs of Rydberg ions. In the second part of this thesis, novel possibilities of using neutral Rydberg atoms for quantum-information processing and quantum simulation are investigated. A new scheme for a multi-atom quantum gate is proposed and theoretically analyzed. This parallelized gate allows one to entangle a mesoscopic ensemble of atoms with a single control atom in a single step, with high fidelity and on a microsecond time scale. The operation relies on strong and long-ranged interactions between Rydberg atoms triggering a
Computer analysis of sodium cold trap design and performance
International Nuclear Information System (INIS)
McPheeters, C.C.; Raue, D.J.
1983-11-01
Normal steam-side corrosion of steam-generator tubes in Liquid Metal Fast Breeder Reactors (LMFBRs) results in liberation of hydrogen, and most of this hydrogen diffuses through the tubes into the heat-transfer sodium and must be removed by the purification system. Cold traps are normally used to purify sodium, and they operate by cooling the sodium to temperatures near the melting point, where soluble impurities including hydrogen and oxygen precipitate as NaH and Na 2 O, respectively. A computer model was developed to simulate the processes that occur in sodium cold traps. The Model for Analyzing Sodium Cold Traps (MASCOT) simulates any desired configuration of mesh arrangements and dimensions and calculates pressure drops and flow distributions, temperature profiles, impurity concentration profiles, and impurity mass distributions
Paul van Ostaijen en het primitivisme
Laan, N.
2010-01-01
Though Paul van Ostaijen has always been put within the context of the historical avant-garde, his relationship to primitivism has never been the subject of study. That is strange, for primitivism is commonly seen as one of the defining characteristics of the avant-garde. Even stranger is that
Classical Sax: Conversation with Paul Brodie.
Row, David W.
1984-01-01
Paul Brodie, the most recorded concert saxophonist in the history of the instrument, talks about a number of topics, including his career, differences among saxophonists, mixing styles of playing, the effectiveness of music schools, and whether it is necessary to understand the structure of the piece being played. (RM)
Rummo, Paul-Eerik, 1942-
2006-01-01
Intervjuus Reformierakonna ühe presidendikandidaadi, rahvastikuminister Paul-Eerik Rummoga käsitletakse presidendi rolli, ülesandeid, rahva ootusi, Eesti ideed Euroopas, EL-i laienemist. Tema hinnangul on võtmeteema haridus, sellest oleneb ka kõige muu õnnestumine, ka rahvuse edasikestmine
International Nuclear Information System (INIS)
Dupre, P.
2011-09-01
The weak equivalence principle, a fundament of Einstein general relativity, states that gravitational mass and inertial mass are equal whatever the body. This equivalence principle has never been directly tested with antimatter. The GBAR (Gravitational Behaviour of Antimatter at Rest) experiment intends to test it by measuring the acceleration of ultra cold anti-hydrogens in free fall. The production of such anti-atoms requires a pulse of about 10 10 positrons in a few tens of nanoseconds. This thesis focuses on the development of a new accumulation technique of positrons in a Penning-Malmberg trap in order to create this pulse. This new method is an improvement of the accumulation technique of Oshima et al.. This technique requires a non-neutral electron plasma to cool down positrons in the trap in order to confine them. A continuous beam delivers positrons and the trapping efficiency is about 0.4%. The new method needs a positron pulsed beam and the method efficiency is estimated at 80%. A part of this thesis was performed at Riken (Tokyo) on the trap of Oshima et al. to study the behavior of non-neutral plasmas in this type of trap and the first accumulation method. A theoretical model was developed to simulate the positron trapping efficiency. The description and the systematic study of the new accumulation technique with a pulsed positron beam are presented. They includes notably the optimization through simulation of the electromagnetic configuration of the trap and of the parameters of the used non-neutral plasmas. (author)
Quantum computation and simulation with trapped ions using dissipation
International Nuclear Information System (INIS)
Schindler, P.
2013-01-01
current quantum systems do not allow for the required level of control. Nevertheless it seems promising to adapt the techniques developed for quantum information processing to build a quantum simulator. Such a device is able to efficiently reproduce the dynamics of any quantum system - a task that is only possible for small systems on existing classical computers. However, the quantum system of interest may be coupled to a classical environment where many examples for such systems can be found in quantum biology and quantum chemistry. These systems are often embedded in a thermal environment and, analogous to classical physics, show non-reversible, or dissipative, dynamics. Thus, also the quantum simulator should be able to reproduce dissipative dynamics which requires an extension of the usual quantum computing toolbox. In the context of quantum computing, such a coupling is usually treated as a noise process that defeats the possible gain from using such a device. Interestingly it has been shown that an environment can be engineered that drives the system towards a state that features entanglement and can serve as a resource for quantum information processing. In this thesis, an extended toolbox that goes beyond coherent operations is introduced in our small-scale ion-trap quantum information processor. This is then used to create an entangled state through dissipative dynamics. In the next step a quantum simulation of a dissipative many-body system is performed, demonstrating the hallmark feature of a novel type of quantum phase transitions. (author) [de
Investigation of SAGD steam trap control in two and three dimensions
Energy Technology Data Exchange (ETDEWEB)
Edmunds, N. R. [Clearwater Engineering, AB (Canada)
1998-12-31
Steam trap production control has been traditionally recommended for steam-assisted gravity drainage (SAGD) operations. This study examines the relationship between producing steam trap subcool settings and related parameters of interest such as fluid level, pressure, production rate, and profitability for a prototype Athabasca reservoir. Study results indicate that the steam trap dynamics are far more complex than hitherto imagined, that 3-D simulations predict significantly lower production rates than 2-D simulations, and that these variations have implications for all aspects of SAGD engineering, including process optimization, production operations and performance analysis. 10 refs., 2 tabs., 15 figs.
Trapped Mode Study in the LHC Rotatable Collimator
Xiao, L; Smith, J C; Caspers, F
2010-01-01
A rotatable collimator is proposed for the LHC phase II collimation upgrade. When the beam crosses the collimator, trapped modes will be excited that result in beam energy loss and collimator power dissipation. Some of the trapped modes can also generate transverse kick on the beam and affect the beam operation. In this paper the parallel eigensolver code Omega3P is used to search for all the trapped modes below 2GHz in the collimator, including longitudinal modes and transverse modes. The loss factors and kick factors of the trapped modes are calculated as function of the jaw positions. The amplitude ratio between transverse and longitudinal trapped mode intensity can be used as a direct measure of the position of the beam. We present simulation results and discuss the results.
Microfabricated Microwave-Integrated Surface Ion Trap
Revelle, Melissa C.; Blain, Matthew G.; Haltli, Raymond A.; Hollowell, Andrew E.; Nordquist, Christopher D.; Maunz, Peter
2017-04-01
Quantum information processing holds the key to solving computational problems that are intractable with classical computers. Trapped ions are a physical realization of a quantum information system in which qubits are encoded in hyperfine energy states. Coupling the qubit states to ion motion, as needed for two-qubit gates, is typically accomplished using Raman laser beams. Alternatively, this coupling can be achieved with strong microwave gradient fields. While microwave radiation is easier to control than a laser, it is challenging to precisely engineer the radiated microwave field. Taking advantage of Sandia's microfabrication techniques, we created a surface ion trap with integrated microwave electrodes with sub-wavelength dimensions. This multi-layered device permits co-location of the microwave antennae and the ion trap electrodes to create localized microwave gradient fields and necessary trapping fields. Here, we characterize the trap design and present simulated microwave performance with progress towards experimental results. This research was funded, in part, by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA).
Sediment Trapping in Estuaries
Burchard, Hans; Schuttelaars, Henk M.; Ralston, David K.
2018-01-01
Estuarine turbidity maxima (ETMs) are generated by a large suite of hydrodynamic and sediment dynamic processes, leading to longitudinal convergence of cross-sectionally integrated and tidally averaged transport of cohesive and noncohesive suspended particulate matter (SPM). The relative importance of these processes for SPM trapping varies substantially among estuaries depending on topography, fluvial and tidal forcing, and SPM composition. The high-frequency dynamics of ETMs are constrained by interactions with the low-frequency dynamics of the bottom pool of easily erodible sediments. Here, we use a transport decomposition to present processes that lead to convergent SPM transport, and review trapping mechanisms that lead to ETMs at the landward limit of the salt intrusion, in the freshwater zone, at topographic transitions, and by lateral processes within the cross section. We use model simulations of example estuaries to demonstrate the complex concurrence of ETM formation mechanisms. We also discuss how changes in SPM trapping mechanisms, often caused by direct human interference, can lead to the generation of hyperturbid estuaries.
Local condensate depletion at trap center under strong interactions
Yukalov, V. I.; Yukalova, E. P.
2018-04-01
Cold trapped Bose-condensed atoms, interacting via hard-sphere repulsive potentials are considered. Simple mean-field approximations show that the condensate distribution inside a harmonic trap always has the shape of a hump with the maximum condensate density occurring at the trap center. However, Monte Carlo simulations at high density and strong interactions display the condensate depletion at the trap center. The explanation of this effect of local condensate depletion at trap center is suggested in the frame of self-consistent theory of Bose-condensed systems. The depletion is shown to be due to the existence of the anomalous average that takes into account pair correlations and appears in systems with broken gauge symmetry.
Strong trapping and slow diffusion of helium in a tungsten grain boundary
Energy Technology Data Exchange (ETDEWEB)
Wang, Xin-Xin [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Niu, Liang-Liang, E-mail: nliangli@umich.edu [Department of Physics, Beihang University, Beijing 100191 (China); Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI 48109 (United States); Wang, Shaoqing [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)
2017-04-15
We have investigated the segregation, trapping and diffusion of He in a ∑3<110>{111} W grain boundary (GB) using combined techniques of ab initio and classical atomistic simulations. We show that, with an average segregation energy of −3.20 eV, the strong He trapping can be attributed to a GB interstitial trapping or a vacancy trapping mechanism, while an average energy barrier of 1.97 eV leads to a slow diffusion of He in the GB plane. We further reveal by molecular dynamics simulations that the He diffusion will be dictated by GB migration through the motion of GB disconnections. Interestingly, we also observe a He-induced GB structural transition in classical simulations. The present work suggests that the GB does not provide fast transport channel for He, providing useful reference for the possible application of polycrystalline W under He irradiation in advanced nuclear fusion reactors.
Ion Motion Stability in Asymmetric Surface Electrode Ion Traps
Shaikh, Fayaz; Ozakin, Arkadas
2010-03-01
Many recently developed designs of the surface electrode ion traps for quantum information processing have asymmetry built into their geometries. The asymmetry helps rotate the trap axes to angles with respect to electrode surface that facilitate laser cooling of ions but introduces a relative angle between the RF and DC fields and invalidates the classical stability analysis of the symmetric case for which the equations of motion are decoupled. For asymmetric case the classical motion of a single ion is given by a coupled, multi-dimensional version of Mathieu's equation. In this poster we discuss the stability diagram of asymmetric surface traps by performing an approximate multiple scale perturbation analysis of the coupled Mathieu equations, and validate the results with numerical simulations. After obtaining the stability diagram for the linear fields, we simulate the motion of an ion in a given asymmetric surface trap, utilizing a method-of-moments calculation of the electrode fields. We obtain the stability diagram and compare it with the ideal case to find the region of validity. Finally, we compare the results of our stability analysis to experiments conducted on a microfabricated asymmetric surface trap.
Dynamic Trap Formation and Elimination in Colloidal Quantum Dots
Voznyy, O.; Thon, S. M.; Ip, A. H.; Sargent, E. H.
2013-01-01
Using first-principles simulations on PbS and CdSe colloidal quantum dots, we find that surface defects form in response to electronic doping and charging of the nanoparticles. We show that electronic trap states in nanocrystals are dynamic entities, in contrast with the conventional picture wherein traps are viewed as stable electronic states that can be filled or emptied, but not created or destroyed. These traps arise from the formation or breaking of atomic dimers at the nanoparticle surface. The dimers' energy levels can reside within the bandgap, in which case a trap is formed. Fortunately, we are also able to identify a number of shallow-electron-affinity cations that stabilize the surface, working to counter dynamic trap formation and allowing for trap-free doping. © 2013 American Chemical Society.
Dynamic Trap Formation and Elimination in Colloidal Quantum Dots
Voznyy, O.
2013-03-21
Using first-principles simulations on PbS and CdSe colloidal quantum dots, we find that surface defects form in response to electronic doping and charging of the nanoparticles. We show that electronic trap states in nanocrystals are dynamic entities, in contrast with the conventional picture wherein traps are viewed as stable electronic states that can be filled or emptied, but not created or destroyed. These traps arise from the formation or breaking of atomic dimers at the nanoparticle surface. The dimers\\' energy levels can reside within the bandgap, in which case a trap is formed. Fortunately, we are also able to identify a number of shallow-electron-affinity cations that stabilize the surface, working to counter dynamic trap formation and allowing for trap-free doping. © 2013 American Chemical Society.
Experiments on cold trap regeneration by NaH decomposition
International Nuclear Information System (INIS)
McPheeters, C.C.; Skladzien, S.B.; Raue, D.J.
1979-10-01
Cold trap regeneration may be very important in future LMFBRs because of the expected high hydrogen source from the steam generators. This hydrogen precipitates as NaH in the cold trap and may fill the trap within one year of operation. Several methods of cold trap regeneration were considered, but the simplest and least expensive appears to be decomposition of NaH under vacuum at elevated temperatures. Experiments were done to assess the feasibility of this method for cold trap regeneration. Small-scale simulated cold traps (SCT) were located with NaH and NaH plus Na 2 O, and were heated both under vacuum and under a sweep gas at 100 kPa. The evolved hydrogen was converted to water by a CuO bed and collected in a weighting tube
Experiments on cold-trap regeneration by NaH decomposition
International Nuclear Information System (INIS)
McPheeters, C.C.; Skladzien, S.B.; Raue, D.J.
1980-06-01
Cold-trap regeneration may be very important in future LMFBRs because of the expected high hydrogen source from the steam generators. This hydrogen precipitates as NaH in the cold trap and may fill the trap within one year of operation. Several methods of cold-trap regeneration were considered, but the simplest and least expensive appears to be decomposition of NaH under vacuum at elevated temperatures. Experiments were done to assess the feasibility of this method for cold-trap regeneration. Small-scale simulated cold traps (SCT) were loaded with NaH and NaH plus Na 2 O, and were heated both under vacuum and under a sweep gas at 100 kPa. The evolved hydrogen was converted to water by a CuO bed and collected in a weighing tube
John Paul College: The Professional Renewal Journey
Directory of Open Access Journals (Sweden)
Pauline Mundie
2014-09-01
Full Text Available John Paul College, a K-12 School in Queensland, Australia, recognises the centrality of classroom teachers to the ongoing improvement of student outcomes. The college has implemented a multi-tiered professional renewal and assessment process. These changes of emphasis are the result of significant research and subsequent/associated professional discussion and were supported during the EBA decision-making in 2012. The professional renewal process at John Paul College guides teachers through a cycle of goal setting (related to any aspect of teacher practice which aims to improve student learning and achievement; ongoing discussion between the teacher and a mentor which determines actions; directed classroom observations (3 per term and associated pre and post reflection/discussion; leading to application of changed practice toward achieving the criteria of the goals. The principles of the professional renewal program are to: enhance development along accepted school-wide, team and department goals; encourage professional pedagogical reflections and conversations with a colleague/mentor; motivate improved performance and highlight the next steps in a teacher’s development. Through the introduction of professional renewal, attestation and exemplary teacher processes, the leadership and teachers of John Paul College have achieved an appropriate and innovative balance between self-directed, peer supported/directed and college-wide, strategic initiatives. Each member of the teaching team, from graduate to senior leaders are actively engaged in personalised programs of professional growth which is specifically aimed at improved learning and outcomes of the college’s students.
The Jesus of Paul: A contribution from the social sciences
Directory of Open Access Journals (Sweden)
Santiago Guijarro
2011-04-01
Determining the relationship between Jesus and Paul is one of the fundamental tasks of those who, like Prof. Andries van Aarde, study the origins of Christianity and the beginnings of Christian theology. The basic question in this regard, at least as it has been formulated recently by David Wenham (1995, is whether Paul was a follower of Jesus or the founder of Christianity (see also Wedderburn [1989] and Barbaglio [2006]. In this brief article, I would like to consider one aspect of this general topic and to offer a few suggestions that might contribute to a better understanding of the peculiar vision of Jesus that we find in the letters of Paul. In them, in fact, the apostle moves from the incarnation to the death and resurrection, leaving in the shadows the activity and teaching of Jesus to which the gospels subsequently give so much importance. This contrast raises some questions concerning the knowledge which Paul had of the Jesus tradition and the value he accorded to it: What did he know about Jesus? Did he know the traditions which the evangelists later collected? Why does he not refer to them in his letters more frequently? By contrast, why does he give so much importance to the death and resurrection of Jesus and to Jesus’ divine condition?
Trapping of Electron Cloud LLC/Cesrta Quadrupole and Sextupole Magnets
International Nuclear Information System (INIS)
Wang, L.
2011-01-01
The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in CESRTA and ILC quadrupole and sextupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with a long lifetime in a quadrupole and sextupole magnet due to the mirror field trapping mechanism. We study the effects of magnet strength, bunch current, ante-chamber effect, bunch spacing effect and secondary emission yield (SEY) in great detail. The development of an electron cloud in magnets is the main concern where a weak solenoid field is not effective. Quadrupole and sextupole magnets have mirror field configurations which may trap electrons by the mirror field trapping mechanism (2). Fig.1 shows the orbit of a trapped electron in a quadrupole magnet. The electron makes gyration motion (called transverse motion) and also moves along the field line (called longitudinal motion). At the mirror point (middle of the field line), there is a maximum longitudinal energy and minimum transverse energy. When the electron moves away from the mirror point, its longitudinal energy reduces and the transverse energy increases as the magnetic field increases. If the magnetic field is strong enough, the longitudinal energy becomes zero at one point and then the electron is turned back by the strong field. Note that the electrons are trapped in the region near the middle of the field lines. Although all quadrupole and sextupole magnets can trap electrons in principle, the
Meet EPA Ecologist Paul Mayer, Ph.D.
EPA ecologist Paul Mayer, Ph.D. works in EPA's Groundwater and Ecosystem Restoration division where he studies riparian zones (the area along rivers and streams where the habitats are influenced by both the land and water) and stream restoration
A Pneumatic Actuated Microfluidic Beads-Trapping Device
Energy Technology Data Exchange (ETDEWEB)
Shao, Guocheng; Cai, Ziliang; Wang, Jun; Wang, Wanjun; Lin, Yuehe
2011-08-20
The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.
Trapped field recovery of bulk superconductor magnets by static field magnetization
Energy Technology Data Exchange (ETDEWEB)
Deng, Z., E-mail: zigang@kaiyodai.ac.jp [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan); Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M. [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan)
2011-11-15
A series of initial trapped fields after ZFC or FC magnetization are used to simulate the attenuated trapped field. It is possible and easy to recover the lost trapped field and regain the best trapped field performance as before. In the re-magnetization process, the initial magnetic flux inside the bulk magnets will help to recover the trapped field. The optimum recovery field is recommended to be 2.5 times the saturation field of the bulk at LN2 temperature. Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa{sub 2}Cu{sub 3}O{sub y} (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.
WHAT HAPPENED TO THE GALATIAN CHRISTIANS? PAUL'S ...
African Journals Online (AJOL)
Paul's Letter to the Galatians points to the influence of his missionary ... of the apostle's name in the first four centuries. .... Acta Theologica Supplementum 19. 2014 .... The author states that they spoke the word in Perge, not implying that they.
Highly charged ion trapping and cooling
International Nuclear Information System (INIS)
Beck, B. R.; Church, D. A.; Gruber, L.; Holder, J. P.; Schneider, D.; Steiger, J.
1998-01-01
In the past few years a cryogenic Penning trap (RETRAP) has been operational at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory. The combination of RETRAP and EBIT provides a unique possibility of producing and re-trapping highly charged ions and cooling them to very low temperatures. Due to the high Coulomb potentials in such an ensemble of cold highly charged ions the Coulomb coupling parameter (the ratio of Coulomb potential to the thermal energy) can easily reach values of 172 and more. To study such systems is not only of interest in astrophysics to simulate White Dwarf star interiors but opens up new possibilities in a variety of areas (e.g. laser spectroscopy), cold highly charged ion beams
XXI sajandi kontuurid / Paul Johnson ; refereerinud Mihkel Mutt
Johnson, Paul
1997-01-01
Washingtonis 14.-16. juunini peetud 'Lääne kirjanduse konverentsil' pidas põhiettekande ameerika ajaloolane ja publitsist Paul Johnson. Refereering tema 'XXI sajandi geopoliitiliste ja kultuuriliste väljavaadete' seisukohtadest
Parameter Screening in Microfluidics Based Hydrodynamic Single-Cell Trapping
Directory of Open Access Journals (Sweden)
B. Deng
2014-01-01
Full Text Available Microfluidic cell-based arraying technology is widely used in the field of single-cell analysis. However, among developed devices, there is a compromise between cellular loading efficiencies and trapped cell densities, which deserves further analysis and optimization. To address this issue, the cell trapping efficiency of a microfluidic device with two parallel micro channels interconnected with cellular trapping sites was studied in this paper. By regulating channel inlet and outlet status, the microfluidic trapping structure can mimic key functioning units of previously reported devices. Numerical simulations were used to model this cellular trapping structure, quantifying the effects of channel on/off status and trapping structure geometries on the cellular trapping efficiency. Furthermore, the microfluidic device was fabricated based on conventional microfabrication and the cellular trapping efficiency was quantified in experiments. Experimental results showed that, besides geometry parameters, cellular travelling velocities and sizes also affected the single-cell trapping efficiency. By fine tuning parameters, more than 95% of trapping sites were taken by individual cells. This study may lay foundation in further studies of single-cell positioning in microfluidics and push forward the study of single-cell analysis.
Obscurity of poetry in Paul Celan
Directory of Open Access Journals (Sweden)
Mauricio Mendonça Cardozo
2012-07-01
Full Text Available Tensioned between variations of the said and the unsaid, and between figures of light and shadow, Paul Celan's work performs a certain confrontation with the condition of silence and obscurity, breaking all at once with a certain way of making poetry and of relating to reality. In this sense, Celan's work can hardly be reduced to a kind of hermeticism, a category too vague to account for its singularity. In his work saying and silencing together articulate the tension that creates the poetic space in which the poem is inscribed. The poet himself tried to refuse the insistence of some critics on labeling his work as obscure. Despite of its fragmentary nature, the recently published manuscripts of his speech project Von der Dunkelheit des Dichterischen constitutes one of Celan’s most extensive discussions of the matter of obscurity in poetry. This paper aims at presenting the fragments of his speech project and pointing out its importance to the discussion of the notion of obscurity in Paul Celan's work.
International Nuclear Information System (INIS)
Fabian, Xavier
2015-01-01
This work belongs to the effort presently deployed to measure the angular correlation parameter a_β_ν in three nuclear beta decays ("6He"+, "3"5Ar"+ and "1"9Ne"+). The V-A structure of the weak interaction implies that a_β_ν = +1 for a pure Fermi transition and a_β_ν = -1/3 for a pure Gamow-Teller transition. A thorough measurement of this parameter to check any deviation from these values may lead to the discovery of possible exotic currents. Furthermore, the measurement of a_β_ν in mirror transitions allows the extraction of V_u_d, the first element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. The LPCTrap apparatus, installed at GANIL, is designed to ready a continuous ion beam for injection in a dedicated Paul trap. This latter device allows to have a quasi-punctual source from which the decay products are detected in coincidence. It is from the study of the recoil ion time-of-flight (TOF) distribution that a_β_ν is withdrawn and, since 2010, the associated Shake-Off (SO) probabilities. This study requires the complete simulation of the LPCTrap experiments. The major part of this work is dedicated to such simulations, especially to the modeling of the trapped ion cloud dynamic. The Clouda program, which takes advantage of graphics processing unit (GPU), was developed in this context and its full characterization is presented here. Three important aspects are addressed: the electromagnetic trapping field, the realistic collisions between the ions and the buffer gas atoms and the space charge effect. The present work shows the importance of these simulations to increase the control of the systematic errors on a_β_ν. (author) [fr
The present day relevance of Paul's advice to the family in the ...
African Journals Online (AJOL)
Many people and organizations have made several efforts to improve and enhance the survival of the family. An example is the advice of Saint Paul, the Apostle to the Christian family in Ephesians 5:22-25 and 6:1-9. This paper examines this advice and its relevance to the society today. Key Words: Paul, Apostle; Advice; ...
International Nuclear Information System (INIS)
Jiang Zhi; Zhuang Yi-Qi; Li Cong; Wang Ping; Liu Yu-Qi
2016-01-01
Trap-assisted tunneling (TAT) has attracted more and more attention, because it seriously affects the sub-threshold characteristic of tunnel field-effect transistor (TFET). In this paper, we assess subthreshold performance of double gate TFET (DG-TFET) through a band-to-band tunneling (BTBT) model, including phonon-assisted scattering and acoustic surface phonons scattering. Interface state density profile (D it ) and the trap level are included in the simulation to analyze their effects on TAT current and the mechanism of gate leakage current. (paper)
Paul Kard and Lorentz-free special relativity
International Nuclear Information System (INIS)
Karlov, L.
1989-01-01
The late Professor Paul Kard of Tartu, Estonia, worked on some interesting derivations of formulae from relativistic kinematics and the dependence of mass on speed. These may prove useful to physics educators as they break the mould of traditional textbook presentations. (UK)
Electron shakeoff following the β+ decay of +19Ne and +35Ar trapped ions
Fabian, X.; Fléchard, X.; Pons, B.; Liénard, E.; Ban, G.; Breitenfeldt, M.; Couratin, C.; Delahaye, P.; Durand, D.; Finlay, P.; Guillon, B.; Lemière, Y.; Mauger, F.; Méry, A.; Naviliat-Cuncic, O.; Porobic, T.; Quéméner, G.; Severijns, N.; Thomas, J.-C.
2018-02-01
The electron shakeoff of 19F and 35Cl atoms resulting from the β+ decay of +19Ne and +35Ar ions has been investigated using a Paul trap coupled to a time of flight recoil-ion spectrometer. The charge-state distributions of the recoiling daughter nuclei were compared to theoretical calculations based on the sudden approximation and accounting for subsequent Auger processes. The excellent agreement obtained for 35Cl is not reproduced in 19F. The shortcoming is attributed to the inaccuracy of the independent particle model employed to calculate the primary shakeoff probabilities in systems with rather low atomic numbers. This calls for more elaborate calculations, including explicitly the electron-electron correlations.
Evidences of trapping in tungsten and implications for plasma-facing components
Longhurst, G. R.; Anderl, R. A.; Holland, D. F.
Trapping effects that include significant delays in permeation saturation, abrupt changes in permeation rate associated with temperature changes, and larger than expected inventories of hydrogen isotopes in the material, were seen in implantation-driven permeation experiments using 25- and 50-micron thick tungsten foils at temperatures of 638 to 825 K. Computer models that simulate permeation transients reproduce the steady-state permeation and reemission behavior of these experiments with expected values of material parameters. However, the transient time characteristics were not successfully simulated without the assumption of traps of substantial trap energy and concentration. An analytical model based on the assumptions of thermodynamic equilibrium between trapped hydrogen atoms and a comparatively low mobile atom concentration successfully accounts for the observed behavior. Using steady-state and transient permeation data from experiments at different temperatures, the effective trap binding energy may be inferred. We analyze a tungsten coated divertor plate design representative of those proposed for ITER and ARIES and consider the implications for tritium permeation and retention if the same trapping we observed was present in that tungsten. Inventory increases of several orders of magnitude may result.
Parallel Narrative Structure in Paul Harding's "Tinkers"
Çirakli, Mustafa Zeki
2014-01-01
The present paper explores the implications of parallel narrative structure in Paul Harding's "Tinkers" (2009). Besides primarily recounting the two sets of parallel narratives, "Tinkers" also comprises of seemingly unrelated fragments such as excerpts from clock repair manuals and diaries. The main stories, however, told…
High-fidelity operations in microfabricated surface ion traps
Maunz, Peter
2017-04-01
Trapped ion systems can be used to implement quantum computation as well as quantum simulation. To scale these systems to the number of qubits required to solve interesting problems in quantum chemistry or solid state physics, the use of large multi-zone ion traps has been proposed. Microfabrication enables the realization of surface electrode ion traps with complex electrode structures. While these traps may enable the scaling of trapped ion quantum information processing (QIP), microfabricated ion traps also pose several technical challenges. Here, we present Sandia's trap fabrication capabilities and characterize trap properties and shuttling operations in our most recent high optical access trap (HOA-2). To demonstrate the viability of Sandia's microfabricated ion traps for QIP we realize robust single and two-qubit gates and characterize them using gate set tomography (GST). In this way we are able to demonstrate the first single qubit gates with a diamond norm of less than 1 . 7 ×10-4 , below a rigorous fault tolerance threshold for general noise of 6 . 7 ×10-4. Furthermore, we realize Mølmer-Sørensen two qubit gates with a process fidelity of 99 . 58(6) % also characterized by GST. These results demonstrate the viability of microfabricated surface traps for state of the art quantum information processing demonstrations. This research was funded, in part, by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA).
Leben mit Estland : Paul-Gerhard von Hoerschelmann zum 80. Geburtstag / Heinrich Wittram
Wittram, Heinrich
2012-01-01
Olles Põhja-Elbe Jutlustajate Seminari direktor alustas Paul-Gerhard von Hoerschelmann koostööd Eesti Evangeelse Luterliku Kirikuga 1988. aastal. Nõmmel sündinud pastori pojana olid tal selle koostöö arendamiseks igati head eeldused. 1997. aastal sai Paul-Gerhard Hoerschelmannist EELK Usuteaduse Instituudi rektor. Aastatel 1996-1998 teenis ta väikesearvulist saksakeelset kogudust Tallinnas. Aastast 2006 EELK' aupraost
Põldma, Vahur-Paul
2008-01-01
Alessandro Baricco teos "Novecento", mida Vahur-Paul Põldma mängib Uue Vana Teatri nime all ühemeheetendusena. Lisaks tutvustus "Kes on Alessandro Baricco?" ja "Vahur-Pauli salaminevik : töö lasteaiakasvatajana"
2010-11-02
... of Attainment by the Applicable Attainment Date for the Hayden, Nogales, Paul Spur/Douglas PM 10... proposes to determine that the Hayden, Nogales, and Paul Spur/Douglas nonattainment areas in Arizona... Hayden, Nogales and Paul Spur/Douglas nonattainment areas are not currently attaining the PM 10 standard...
Leibnitz, L; Werner, L; Schober, W; Brauer, K
1977-04-01
A review is given on the development of the brain research institute of the Karl-Marx-University of Leipzig during the directorates of Paul Flechsig (1883-1920), Richard Arwed Pfeifer (1925-1957), and Wolfgang Wünscher (1957-1971).
Optical waveguide loop for planar trapping of blood cells and microspheres
Ahluwalia, Balpreet S.; Hellesø, Olav G.
2013-09-01
The evanescent field from a waveguide can be used to trap and propel a particle. An optical waveguide loop with an intentional gap at the center is used for planar transport and stable trapping of particles. The waveguide acts as a conveyor belt to trap and deliver spheres towards the gap. At the gap, the counter-diverging light fields hold the sphere at a fixed position. Numerical simulation based on the finite element method was performed in three dimensions using a computer cluster. The field distribution and optical forces for rib and strip waveguide designs are compared and discussed. The optical force on a single particle was computed for various positions of the particle in the gap. Simulation predicted stable trapping of particles in the gap. Depending on the gap separation (2-50 μm) a single or multiple spheres and red blood cells were trapped at the gap. Waveguides were made of tantalum pentaoxide material. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip.
Microwave quantum logic gates for trapped ions.
Ospelkaus, C; Warring, U; Colombe, Y; Brown, K R; Amini, J M; Leibfried, D; Wineland, D J
2011-08-10
Control over physical systems at the quantum level is important in fields as diverse as metrology, information processing, simulation and chemistry. For trapped atomic ions, the quantized motional and internal degrees of freedom can be coherently manipulated with laser light. Similar control is difficult to achieve with radio-frequency or microwave radiation: the essential coupling between internal degrees of freedom and motion requires significant field changes over the extent of the atoms' motion, but such changes are negligible at these frequencies for freely propagating fields. An exception is in the near field of microwave currents in structures smaller than the free-space wavelength, where stronger gradients can be generated. Here we first manipulate coherently (on timescales of 20 nanoseconds) the internal quantum states of ions held in a microfabricated trap. The controlling magnetic fields are generated by microwave currents in electrodes that are integrated into the trap structure. We also generate entanglement between the internal degrees of freedom of two atoms with a gate operation suitable for general quantum computation; the entangled state has a fidelity of 0.76(3), where the uncertainty denotes standard error of the mean. Our approach, which involves integrating the quantum control mechanism into the trapping device in a scalable manner, could be applied to quantum information processing, simulation and spectroscopy.
Ions kinematics in an electrostatic ion beam trap
Energy Technology Data Exchange (ETDEWEB)
Attia, D
2004-06-01
In this study, I have tried to provide a better understanding of the dynamics of ions inside an electrostatic ion beam trap. The electrostatic ion trap allows to store ions moving between two electrostatic mirrors. Although the trap has been developed already seven years ago, no direct measurement of the transversal velocity distribution of the ions has been performed. Such quantity is central for understanding the conditions under which a beam should be produced (mainly emittance) in order to be trapped by such a device. The data I have obtained during the course of this work are based on an experimental technique which relies on the direct imaging of the particles exiting the trap, as well as on numerical simulations of the ion trajectories inside the trap. I have personally been involved in the hardware development of the imaging system, the data acquisition and analysis of the data as well as il all numerical calculations presented here. These results allow us to obtain, for the first time, experimental information on the transverse phase space of the trap, and contribute to the overall understanding of the ion motion in this system. (author)
Trap-nests for stingless bees (Hymenoptera, Meliponini)
Oliveira , Ricardo; Menezes , Cristiano; Soares , Ademilson; Fonseca , Vera
2012-01-01
International audience; Most stingless bee species build their nests inside tree hollows. In this paper, we present trap-nest containers which simulate nesting cavities so as to attract swarms of stingless bees. Although regularly used by stingless bee beekeepers in Brazil, this technique to obtain new colonies has not yet been systematically studied. We used two different types of trap-nests (plastic and cardboard) of four different sizes (0.5, 1.0, 2.0, and 3.0 L) containing propolis extrac...
Paul Lacoste, Portraits sensibles
Laplace-Treyture, Danièle
2013-01-01
Des vignerons indépendants et non pas coopérateurs ; des parcelles accrochées à des versants au lieu d’une vaste plaine viticole ; des vins certifiés bio et un vignoble en biodynamie... C’est autour de Jonquières et d’Aniane (communes situées entre Lodève et Montpellier), que Paul Lacoste a choisi de filmer un nouveau « tournant qualitatif » pris par la viticulture en Languedoc. Le documentaire (un feuilleton en six épisodes) bouscule quelque peu nos représentations collectives de ce Midi vit...
The PAUL Suit(©) : an experience of ageing.
Bennett, Paul; Moore, Malcolm; Wenham, John
2016-04-01
An ageing population worldwide makes it increasingly important that health students understand issues that elderly people face and can provide empathic care to them. This teaching department in an isolated rural setting developed an interprofessional learning session to assist health students to understand issues of functional loss and social isolation that can affect elderly people. The Premature Ageing Unisex Leisure (PAUL) Suit(©) was developed as part of a 1-day learning session for undergraduate health students - including students of medicine, nursing and allied health - attending clinical placement in far-west New South Wales. The suit was developed locally and can be adjusted to simulate a wide range of functional losses in the wearer. Students undertake a range of daily tasks in the community while wearing the suit in the company of a student 'carer'. Over the past 4 years, approximately 140 students have participated in the simulation. Post-simulation evaluations report that students gain a greater understanding of some functional issues associated with ageing, and of the social isolation that can be associated with these. The experiential nature of the activity leads to some powerful insights. This activity is an innovative, experiential tool to deepen students understanding of issues related to ageing This activity is an innovative, experiential tool to deepen students understanding of issues relating to ageing. The interprofessional nature of the activity is an important factor in the success of the day, and produces a wide range of shared insights. The activity also enhances the partnerships between the university, the health service and the local community. Our experience supports the value of simulation in providing a deep learning opportunity in the area of ageing and disability. © 2015 John Wiley & Sons Ltd.
Paul Langerhans: a prilgrim "traveling" from functional histology to marine biology.
Raica, Marius; Cimpean, Anca Maria
2017-06-01
The nineteenth century was the time of a real revolution in science and medicine. A lot of seminal discoveries in medicine and biology were done in this time, and many of them were coincident with the introduction of the compound microscope by Hermann van Deijl and the standard histological technique by Paul Ehrlich. The main tissue types and individual cells were characterized and originally classified more than hundred years ago, although less attention was paid to their basic functions. This was mainly due to the modality of tissue specimen processing that allowed particularly detailed descriptive studies. Even so, we can notice some attempts to correlate the structure with the function. The German scientist Paul Langerhans, well-known for the discovery of Langerhans islets of the pancreas and Langerhans cells from the epidermis, tried to change the conventional fate of morphological studies introducing in his works functional hypothesis based on traditional microscopic observations even from the beginning of his scientific career. Paul Langerhans was a complex personality of the second half of the nineteenth century, not only in medicine, but also in other fields of biology. In the present review, presented is the life and research activity of Paul Langerhans, not only because of the importance of his discoveries, but also for perspectives that were opened by these findings in unexpected fields of medicine and biology.
Observation of Hyperfine Transitions in Trapped Ground-State Antihydrogen
Olin, Arthur
2015-01-01
This paper discusses the first observation of stimulated magnetic resonance transitions between the hyperfine levels of trapped ground state atomic antihydrogen, confirming its presence in the ALPHA apparatus. Our observations show that these transitions are consistent with the values in hydrogen to within 4~parts~in~$10^3$. Simulations of the trapped antiatoms in a microwave field are consistent with our measurements.
Observation of hyperfine transitions in trapped ground-state antihydrogen
Energy Technology Data Exchange (ETDEWEB)
Collaboration: A. Olin for the ALPHA Collaboration
2015-08-15
This paper discusses the first observation of stimulated magnetic resonance transitions between the hyperfine levels of trapped ground state atomic antihydrogen, confirming its presence in the ALPHA apparatus. Our observations show that these transitions are consistent with the values in hydrogen to within 4 parts in 10{sup 3}. Simulations of the trapped antiatoms in a microwave field are consistent with our measurements.
International Nuclear Information System (INIS)
Fujiwara, Shingo; Hasegawa, Shuichi
2005-01-01
It is well known that, in order to build the universal quantum circuit, one only needs one-qubit rotation gate and two-qubit controlled-NOT gate and until now quantum networks have been built from these gates. However, the minimum components of quantum networks in real experiments are not these quantum gates, so we develop a general method for realizing the conditional phase-shift gate in multiqubit ion-trap quantum computation which has the scalability to N qubits (N≥3). The duration of the laser manipulations for the proposed conditional phase-shift gate is almost the same as that for the controlled-NOT gate in ion-trap quantum computation. Moreover, we simulate Grover's algorithm taking into consideration the real laser fluctuations and analyze the effect of decoherence on the practical search
Walking Between Houses, Paul Julien in Sudan
Elsadig Mohamed; Andrea Stultiens
2015-01-01
April 2015 Sudanese photographer Elsadig Mohamed and I tried to relate the photographs that Paul Julien made when traveling through the country in 1933 and 1948 to stories and realities alive in present day Sudan. This initial research was pretty successful and we thought a first presentation of the
Walking between houses, Paul Julien in Sudan
Stultiens, Andrea; Mohamed, Elsadig
2015-01-01
April 2015 Sudanese photographer Elsadig Mohamed and I tried to relate the photographs that Paul Julien made when traveling through the country in 1933 and 1948 to stories and realities alive in present day Sudan. This initial research was pretty successful and we thought a first presentation of the
A versatile electrostatic trap with open optical access
Li, Sheng-Qiang; Yin, Jian-Ping
2018-04-01
A versatile electrostatic trap with open optical access for cold polar molecules in weak-field-seeking state is proposed in this paper. The trap is composed of a pair of disk electrodes and a hexapole. With the help of a finite element software, the spatial distribution of the electrostatic field is calculated. The results indicate that a three-dimensional closed electrostatic trap is formed. Taking ND3 molecules as an example, the dynamic process of loading and trapping is simulated. The results show that when the velocity of the molecular beam is 10 m/s and the loading time is 0.9964 ms, the maximum loading efficiency reaches 94.25% and the temperature of the trapped molecules reaches about 30.3 mK. A single well can be split into two wells, which is of significant importance to the precision measurement and interference of matter waves. This scheme, in addition, can be further miniaturized to construct one-dimensional, two-dimensional, and three-dimensional spatial electrostatic lattices.
Directory of Open Access Journals (Sweden)
A. Wolters
2011-06-01
Full Text Available Since the 1980s there has been a debate among New Testament scholars about the meaning of the Greek word “kephalē” (“head” in the Pauline epistles. Some scholars defend the traditional view that it means “leader”, while others argue that it should be understood to mean “source”. One result of this debate is that it is now clear that both the traditional and the new interpretation of kephalē have very little support in general Greek usage before the New Testament. This article seeks to advance the debate by showing that the phenomenon of “semantic borrowing” can explain why the meaning “source” is effectively limited to one passage in Herodotus,and the meaning “leader” is only found in Greek works written by bilingual Jews. The passage in Herodotus probably reflects a semantic loan from Old Persian *sar while various places in the Septuagint, Philo, Josephus and Paul reflect a semantic loan from Hebrew “ro’sh” (or Aramaic “re’sh”. Because the latter semantic loan (“head” meaning “leader” is embedded in the Greek Bible (both in the Septuagint and Paul,the authority and prestige of the latter can account for the fact that the new meaning of kephalē, though unknown in previous pagan Greek writings, gradually became widespread in postbiblical Greek as Christianity spread.
Kuimet, Paul, 1984-
2016-01-01
Paul Kuimet, Dénes Kalev Farkas ja Laura Kuusk räägivad, kuidas valmisid nende kunstnikuraamatud ja mis oli projekti tõukejõuks. Paul Kuimeti fotoraamat "In Vicinity", Dénes Kalev Farkasi raamatud "Evident in Advance" ja "Credo", Laura Kuuse raamat "Pop-up-book"
Wang, Y.; Porter, W.; Miller, P. A.; Graham, R. W.; Williams, J. W.
2016-12-01
Estimate of megafauna behaviors dynamically under associated environmental factors is important to understand the mechanisms and causes of the late Quaternary megafaunal extinctions. On St. Paul Island, an isolated remnant of the Bering Land Bridge, a late-surviving population of woolly mammoth (Mammuthus primigenius) persisted until 5,600 cal BP, while 37 out of 54 megafauna species in the continent of North America, all herbivores, went extinct at the end of Pleistocene between 13,800 and 11,500 cal BP. Proposed natural drivers of the extinction events include abrupt temperature changes, food resource loss and freshwater shortage. Here we tested these three hypothesized mechanisms, using a physiological model (Niche Mapper) to estimate individual megafauna behaviors from the perspectives of metabolic rate, individual vegetation and freshwater requirement under simulated climates from Community Climate System Model version 3 (CCSM3), vegetation reconstructions based on dynamic LPJ-GUESS model and woolly mammoth and megafauna species trait data reconstructed based on mammal fossils. Preliminary simulations of woolly mammoth on St. Paul Island point to the importance of net vegetation primary productivity and freshwater availability as limits on the carrying capacity of St. Paul for mammoth populations, with a low carrying capacity in the middle Holocene making this population highly vulnerable to extinction. Results also indicate that the abrupt warming based around 14,000 cal BP in Bering land bridge on CCSM3 simulations causes woolly mammoth extinction, by driving metabolic rate high up beyond the active basic metabolic rate. Analysis suggests a positive relationship between temperature and metabolic rate, and woolly mammoth would go extinct when summer temperature is up to 12 °C or higher. However the temperature reconstructed based on regional proxies is relatively stable compared to CCSM3 simulations, and leads to stable metabolic rate of woolly mammoth and
MOS Capacitance—Voltage Characteristics III. Trapping Capacitance from 2-Charge-State Impurities
International Nuclear Information System (INIS)
Jie Binbin; Sah Chihtang
2011-01-01
Low-frequency and high-frequency capacitance—voltage curves of Metal—Oxide—Semiconductor Capacitors are presented to illustrate giant electron and hole trapping capacitances at many simultaneously present two-charge-state and one-trapped-carrier, or one-energy-level impurity species. Models described include a donor electron trap and an acceptor hole trap, both donors, both acceptors, both shallow energy levels, both deep, one shallow and one deep, and the identical donor and acceptor. Device and material parameters are selected to simulate chemically and physically realizable capacitors for fundamental trapping parameter characterizations and for electrical and optical signal processing applications. (invited papers)
Science in culture the life of Paul Dirac
Abbott, A
2000-01-01
The life of Paul Dirac has been used as the theme of a show held underground at the Delphi experiment at CERN. The 'Oracle of Delphi' was created as an outreach project and has been extremely successful (1 p).
Self-driven particles in linear flows and trapped in a harmonic potential
Sandoval, Mario; Hidalgo-Gonzalez, Julio C.; Jimenez-Aquino, Jose I.
2018-03-01
We present analytical expressions for the mean-square displacement of self-driven particles in general linear flows and trapped in a harmonic potential. The general expressions are applied to three types of linear flows, namely, shear flow, solid-body rotation flow, and extensional flow. By using Brownian dynamics simulations, the effect of trapping and external linear flows on the particles' distribution is also elucidated. These simulations also enabled us to validate our theoretical results.
Paul Voosen Receives 2013 David Perlman Award for Excellence in Science Journalism—News: Citation
Zaneski, Cyril T.
2014-01-01
It's my pleasure to nominate Paul Voosen, the former science reporter for Greenwire, for the David Perlman award. Last November, as Superstorm Sandy pounded the East Coast of the United States, Paul found himself stranded for several days in Miami, mourning a recently deceased family member.
Zhi, Jiang; Yi-Qi, Zhuang; Cong, Li; Ping, Wang; Yu-Qi, Liu
2016-02-01
Trap-assisted tunneling (TAT) has attracted more and more attention, because it seriously affects the sub-threshold characteristic of tunnel field-effect transistor (TFET). In this paper, we assess subthreshold performance of double gate TFET (DG-TFET) through a band-to-band tunneling (BTBT) model, including phonon-assisted scattering and acoustic surface phonons scattering. Interface state density profile (Dit) and the trap level are included in the simulation to analyze their effects on TAT current and the mechanism of gate leakage current. Project supported by the National Natural Science Foundation of China (Grant Nos. 61574109 and 61204092).
Quantum Information Experiments with Trapped Ions at NIST
Wilson, Andrew
2015-03-01
We present an overview of recent trapped-ion quantum information experiments at NIST. Advancing beyond few-qubit ``proof-of-principle'' experiments to the many-qubit systems needed for practical quantum simulation and information processing, without compromising on the performance demonstrated with small systems, remains a major challenge. One approach to scalable hardware development is surface-electrode traps. Micro-fabricated planar traps can have a number of useful features, including flexible electrode geometries, integrated microwave delivery, and spatio-temporal tuning of potentials for ion transport and spin-spin interactions. In this talk we report on a number of on-going investigations with surface traps. Experiments feature a multi-zone trap with closely spaced ions in a triangular arrangement (a first step towards 2D arrays of ions with tunable spin-spin interactions), a scheme for smooth transport through a junction in a 2D structure based on switchable RF potentials, and a micro-fabricated photo-detector integrated into a trap. We also give a progress report on our latest efforts to improve the fidelity of both optical and microwave 2-qubit gates. This work was supported by IARPA, ONR and the NIST Quantum Information Program. The 3-ion and switchable-RF-junction traps were developed in collaboration with Sandia National Laboratory.
Information entropy of a time-dependent three-level trapped ion interacting with a laser field
International Nuclear Information System (INIS)
Abdel-Aty, Mahmoud
2005-01-01
Trapped and laser-cooled ions are increasingly used for a variety of modern high-precision experiments, frequency standard applications and quantum information processing. Therefore, in this communication we present a comprehensive analysis of the pattern of information entropy arising in the time evolution of an ion interacting with a laser field. A general analytic approach is proposed for a three-level trapped-ion system in the presence of the time-dependent couplings. By working out an exact analytic solution, we conclusively analyse the general properties of the von Neumann entropy and quantum information entropy. It is shown that the information entropy is affected strongly by the time-dependent coupling and exhibits long time periodic oscillations. This feature attributed to the fact that in the time-dependent region Rabi oscillation is time dependent. Using parameters corresponding to a specific three-level ionic system, a single beryllium ion in a RF-(Paul) trap, we obtain illustrative examples of some novel aspects of this system in the dynamical evolution. Our results establish an explicit relation between the exact information entropy and the entanglement between the multi-level ion and the laser field. We show that different nonclassical effects arise in the dynamics of the ionic population inversion, depending on the initial states of the vibrational motion/field and on the values of Lamb-Dicke parameter η
76 FR 73666 - Notice of Inventory Completion: Paul H. Karshner Memorial Museum, Puyallup, WA
2011-11-29
..., 2011. ADDRESSES: Brian Fox, Director of Instructional Leadership, Puyallup School District, Paul H... American. Pursuant to 25 U.S.C. 3001(2), a relationship of shared group identity cannot be reasonably... criteria in 43 CFR 10.11(c)(1) should contact Brian Fox, Director of Instructional Leadership, Paul H...
International Nuclear Information System (INIS)
Racko, J.; Benko, P.; Grmanova, A.; Harmatha, L.; Breza, J.; Granzner, R.; Schwierz, F.
2013-01-01
The described trap-assisted tunnelling (TAT) model of the metal/GaN/Al_xGaN_1_-_x/GaN structure allows analyzing the effect of deep traps upon I-V and C-V characteristics. The negative charge with magnitude proportional to the molar concentration of aluminium gives rise to a barrier at the first heterojunction, which is higher than the Schottky barrier at the metal/GaN interface. On increasing the reverse bias Va the barrier at the first heterojunction is getting lower. The drop of this barrier causes an exponential increase of the reverse current. The current saturates, when the first heterojunction barrier is lower than the Schottky barrier. The effect of TAT can be observed also on varying the parameters of the band of traps. The shape of the simulated C-V curve is affected by changes in the charge on the second heterojunction. In principle it reflects the decrease of electron concentration in the quantum well on increasing the reverse bias V_a. The space charge region becomes wider and the electron concentration at the second heterojunction falls below the concentration of ionized deep trapping centres, which manifests itself as a noticeable drop in the capacitance of the metal/GaN/Al_xGaN_1_-_x/GaN structure. (authors)
2013-08-02
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. OR13-28-000] St. Paul Park..., 2013, St. Paul Park Refining Co. LLC (Complainant) filed a formal complaint against Enbridge Pipelines... regulatory basis. St. Paul Park Refining Co. LLC certifies that copies of the complaint were served on the...
Trapped charged particles a graduate textbook with problems and solutions
Madsen, Niels; Thompson, Richard C
2016-01-01
At Les Houches in January 2015, experts in the field of particle trapping came together to discuss the fundamental physics of traps and the different types of applications. This textbook collates the lectures delivered there; the Second Winter School on Physics with Trapped Charged Particles. Taken as a whole, the book gives an overview of why traps for charged particles are important, how they work, their special features and limitations, and their application in areas such as precision measurements, mass spectrometry, optical clocks, plasma physics, antihydrogen creation, quantum simulation and quantum information processing. Chapters from various world experts include those on the basic properties of Penning traps, RF traps and particle accelerators, as well as those covering important practical aspects such as vacuum systems, detection techniques, and different types of particle cooling including laser cooling. Finally, individual chapters deal with the different areas of application listed above. Each ...
Modern historical epistemology through the prism of Paul Ricoeur’ transactions
Directory of Open Access Journals (Sweden)
Trubnikova Natalia
2016-01-01
Full Text Available In this article it is carried out the contribution of Paul Ricoeur, the leading theorist of modern humanitarian knowledge, in the elaboration of the modern historical epistemology problems. His diverse works affect all sense fields of history and historical perception. The article shows the place of Paul Ricoeur as a primary guide of philosophical hermeneutic tradition achievements in the sphere of historical research, moreover, as a thinker, who gives a principal possibility to surmount divisions of different historiographical trends and find a methodological consensus in regard to basic orientations of historical scholarship. On the basis of his works the dialectic of a historical objectivity and a personal subjectivity of historian, the interoperability issues of history and historical memory are traced. At the same time this paper touches principals dichotomies, basic for the Paul Ricoeur’s considerations, such as fiction and historical narration, structure and event, history and truth, memory and imagination, scientism and art of interpretation, human action and social constraint. The contents of a current debate on the theory of history, based on the development of the Ricoeur’s “defatalisation” of history concept and utopian future vision are shown.
Alliksaar: rohkem kui legend / Paul-Eerik Rummo
Rummo, Paul-Eerik, 1942-
2010-01-01
Artur Alliksaare avaldusest, mis pärineb tema toimikust (NSVL Justiitsministeeriumi parandusliku töö laagrite režiimi- ja operatiivosakonna toimik nr. 5348). Avalduses annab Artur Alliksaar end üles kui Saksa sõjaväe vabatahtliku. Vt ka Paul-Eerik Rummo artiklit "Artur Alliksaare dokumenteeritud legend" ajakirjas Keel ja Kirjandus, 2003, nr. 4.
Paul W. Kruse (1927-2012), In Memoriam
Reine, Marion B.; Norton, Paul R.; Stelzer, Ernie L.
2013-06-01
During his distinguished 37-year career as a research physicist at the Honeywell Research Center in Minneapolis, Minnesota, Dr. Paul W. Kruse (1927-2012) played leadership roles in two disruptive infrared detector technologies, the narrow-gap semiconductor alloy HgCdTe and the silicon CMOS-based microbolometer array, both of which revolutionized the worldwide infrared detector industry. He served on numerous government advisory boards and panels, including the Army Scientific Advisory Panel and the Army Science Board, for which he received the Outstanding Civilian Service Medal. After retiring for Honeywell in 1993, he remained active in the infrared detector field in several roles: as a successful small-business entrepreneur, as an author of two books, and as a SPIE lecturer. His books, papers and lectures have educated new generations of workers in the infrared detector industry. His career, a model for industrial research physicists, has had major and permanent impacts on the worldwide infrared detector industry. This paper is a summary of the career of Paul W. Kruse, as well as a tribute to that career and its lasting legacy.
1981-09-01
formal consultation process should be initiated. This should be done by writing to the Regional Director, U. S. Fish and Wildlife Service, Federal...16 5 FC.F PIPFRiF G;~IPHFiTIOtl LAYEP THIi>.NE*:7. 12. Ilit HES’ PERCENT LI’THTEP LIfIIT:- OFTfE B:Y WJEIGHT (JE,: I GHT LI. 15 12 wRITE FUAJLT- OIF...Paul to 8 inches in the headwaters. Cold weather nearly halted snow ielt runoff during the latter part of March, allowing many streams to drop below
77 FR 41168 - Marine Mammals; Subsistence Taking of Northern Fur Seals; St. Paul Island
2012-07-12
... Administrative Procedure Act (APA). The Pribilof Island Community of St. Paul Island, Aleut Community of St. Paul... comment on from the resulting list and click on the ``Submit a Comment'' icon on the right of that line... Adobe PDF file formats only. Information related to the request for rulemaking is available on the...
Plasmon assisted optical trapping: fundamentals and biomedical applications
Serafetinides, Alexandros A.; Makropoulou, Mersini; Tsigaridas, Georgios N.; Gousetis, Anastasios
2015-01-01
The field of optical trapping has dramatically grown due to implementation in various arenas including physics, biology, medicine and nanotechnology. Certainly, optical tweezers are an invaluable tool to manipulate a variation of particles, such as small dielectric spheres, cells, bacteria, chromosomes and even genes, by highly focused laser beams through microscope. As the main disadvantage of the conventional optical trapping systems is the diffraction limit of the incident light, plasmon assisted nanotrapping is reported as a suitable technique for trapping sub-wavelength metallic or dielectric particles. In this work, firstly, we report briefly on the basic theory of plasmon excitation, focusing on the interaction of nanoscale metallic structures with laser light. Secondly, experimental and numerical simulation results are also presented, demonstrating enhancement of the trapping efficiency of glass or SiO2 substrates, coated with Au and Ag nanostructures, with or without nanoparticles. The optical forces were calculated by measuring the particle's escape velocity calibration method. Finally, representative applications of plasmon assisted optical trapping are reviewed, from cancer therapeutics to fundamental biology and cell nanosurgery.
International Nuclear Information System (INIS)
Feret, B.; Bartczak, W.M.; Kroh, J.
1991-01-01
The Redi-Hopefield quantum mechanical model of the thermally-assisted electron transfer has been applied to simulate the decay of trapped electrons by tunnelling to electron acceptor molecules added to the glassy matrix. It was assumed that the electron energy levels in donors and acceptors are statistically distributed and the electron excess energy after transfer is dissipated in the medium by the electron-phonon coupling. The electron decay curves were obtained by the method of computer simulation. It was found that for a given medium there exists a certain preferred value of the electronic excess energy which can be effectively converted into the matrix vibrations. If the mismatch of the electron states on the donor and acceptor coincides with the ''resonance'' energy the overall kinetics of electron transfer is accelerated. (author)
Quantitative study of the trapped particle bunching instability in Langmuir waves
International Nuclear Information System (INIS)
Hara, Kentaro; Boyd, Iain D.; Chapman, Thomas; Joseph, Ilon; Berger, Richard L.; Banks, Jeffrey W.; Brunner, Stephan
2015-01-01
The bunching instability of particles trapped in Langmuir waves is studied using Vlasov simulations. A measure of particle bunching is defined and used to extract the growth rate from numerical simulations, which are compared with theory [Dodin et al., Phys. Rev. Lett. 110, 215006 (2013)]. In addition, the general theory of trapped particle instability in 1D is revisited and a more accurate description of the dispersion relation is obtained. Excellent agreement between numerical and theoretical predictions of growth rates of the bunching instability is shown over a range of parameters
Quantitative study of the trapped particle bunching instability in Langmuir waves
Energy Technology Data Exchange (ETDEWEB)
Hara, Kentaro, E-mail: kenhara@umich.edu; Boyd, Iain D. [Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Chapman, Thomas; Joseph, Ilon; Berger, Richard L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Banks, Jeffrey W. [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Brunner, Stephan [Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Ecole Polytechnique Fédérale de Lausanne, CRPP-PPB, CH-1015 Lausanne (Switzerland)
2015-02-15
The bunching instability of particles trapped in Langmuir waves is studied using Vlasov simulations. A measure of particle bunching is defined and used to extract the growth rate from numerical simulations, which are compared with theory [Dodin et al., Phys. Rev. Lett. 110, 215006 (2013)]. In addition, the general theory of trapped particle instability in 1D is revisited and a more accurate description of the dispersion relation is obtained. Excellent agreement between numerical and theoretical predictions of growth rates of the bunching instability is shown over a range of parameters.
International Nuclear Information System (INIS)
Lang, Peter; Rath, Markus; Kozeschnik, Ernst; Rivera-Diaz-del-Castillo, Pedro E.J.
2015-01-01
Hydrogen trapping behaviour is investigated by means of thermokinetic simulations in a martensitic steel. The heat treatment consists of austenitisation followed by quenching and tempering. The model prescribes a minimum in hydrogen trapping at an austenitisation temperature of 1050 °C. Below this temperature, austenite grain boundaries are the prevailing trap, whereas niobium atoms in solid solution are the main traps above 1050 °C. The model describes precisely the experimental results
2013-12-16
... Paul's Tank Cleaning Service Superfund Site, Burlington County, New Jersey AGENCY: Environmental.... (``Settling Party''). The Settling Party is a potentially responsible party, pursuant to Section 107(a) of CERCLA, and thus is potentially liable for response costs incurred at or in connection Paul's Tank...
Design of a high field uniformity electromagnet for Penning trap
International Nuclear Information System (INIS)
Itteera, Janvin; Singh, Kumud; Teotia, Vikas; Ukarde, Priti; Malhotra, Sanjay; Taly, Y.K.; Joshi, Manoj; Rao, Pushpa
2013-01-01
An ion trap (Penning trap) facility is being developed at BARC for spectroscopy studies. This requires the design of an iron core electromagnet capable of generating high magnetic fields (∼1.7T) at the centre of an 88 mm long air gap. This electromagnet provides the requisite dipole magnetic field which when superimposed on the electrostatic quadrupoles ensures a stable trapping of ions. To conduct high precision spectroscopy studies, we need to ensure a high degree of magnetic field uniformity ( 3 volume (Trap zone). Various pole shoe profiles were studied and modelled, FEM simulation of the same were conducted to compute the magnetic field intensity and field uniformity. Owing to the large air gap and requirement of high field intensity in the GFR, the exciting coils need to handle high current densities, which require water cooled systems. Double Pan-Cake coil design is selected for powering the magnet. Electrical, thermal and hydraulic designs of the coils are completed and a prototype double pancake coil was fabricated and tested for verifying the electrical and thermal parameter. The spatial field homogeneity is achieved by shimming the pole tip. Temporal stability of magnet requires a highly stable power supply for exciting the coils and its stability class is derived from FEM simulations. This paper discusses the electromagnetic design and development of the penning trap magnet being developed at BARC. (author)
Kohler, Susanna
2017-10-01
Kraus (University of Exeter) in a recent publication. Kraus and collaborators show that the protoplanetary disk of V1247 Orionis contains a ring-shaped, asymmetric inner disk component, as well as a sharply confined crescent structure. These structures are consistent with the morphologies expected from theoretical models of vortex formation in disks.Kraus and collaborators propose the following picture: an early planet is orbiting at 100 AU within the disk, generating a one-armed spiral arm as material feeds the protoplanet. As the protoplanet orbits, it clears a gap between the ring and the crescent, and it simultaneously triggers two vortices, visible as the crescent and the bright asymmetry in the ring. These vortices are then able to trap millimeter-sized particles.Gas column density of the authors radiation-hydrodynamic simulation of V1247 Orioniss disk. [Kraus et al. 2017]The authors run detailed hydrodynamics simulations of this scenario and compare them (as well as alternative theories) to the ALMA observations of V1247 Orionis. The simulations support their model, producing sample scattered-light images thatmatchwell the one-armed spiral observed in previous scattered-light images of the disk.How can we confirm V1247 Orionis providesan example of dust-trapping vortices? One piece of supporting evidence would be the discovery of the protoplanet that Kraus and collaborators theorize triggered the potential vortices in this disk. Future deeper ALMA imaging may make this possible, helping to confirm our picture of how dust builds into planets.CitationStefan Kraus et al 2017 ApJL 848 L11. doi:10.3847/2041-8213/aa8edc
Hermeneutics in identity formation: Paul's use of Genesis in ...
African Journals Online (AJOL)
Test
2010-08-06
Aug 6, 2010 ... psychological functioning and large-scale social processes .... the Christian's life of service to God as a spiritual battle; however, military terms dominate .... subscribes to Dunn's thesis that Paul's law-polemic addressed Jewish ...
Schemes for loading a Bose-Einstein condensate into a two-dimensional dipole trap
International Nuclear Information System (INIS)
Colombe, Yves; Kadio, Demascoth; Olshanii, Maxim; Mercier, Brigitte; Lorent, Vincent; Perrin, Helene
2003-01-01
We propose two loading mechanisms of a degenerate Bose gas into a surface trap. This trap relies on the dipole potential produced by two evanescent optical waves far detuned from the atomic resonance, yielding a strongly anisotropic trap with typical frequencies 40 Hz x 65 Hz x 30 kHz. We present numerical simulations based on the time-dependent Gross-Pitaevskii equation of the transfer process from a conventional magnetic trap into the surface trap. We show that, despite a large discrepancy between the oscillation frequencies along one direction in the initial and final traps, a loading time of a few tens of milliseconds would lead to an adiabatic transfer. Preliminary experimental results are presented
Biri, S; Hitz, D
1999-01-01
At the Paul Scherrer Institut ( PSI, Switzerland) an experimental program is started to measure the ground state shift and width of pionic hydrogen. To calibrate the crystal spectrometer X-ray transitions in hydrogen-like heavy ions (e.g. Ar17+) produced by ECR ion sources, are necessary. In PSI a superconducting cyclotron trap magnet originally developed for high energy experiments will be transformed into an ECR Ion Trap (ECRIT). The SC-magnet can deliver more than 4 Tesla magnetic fields with a mirror ratio of 2. A careful calculation showed this mirror ratio can be increased upto 10 and the trap can operate with frequencies between 5 and 20 GHz. To form a closed resonance zone a relatively large open structure (LBL-AECRU-type) NdFeB hexapole will be applied. The first tests will be performed with 6.4 GHz. Later higher frequencies (10 or 14.5 GHz) and the 2-frequency heating (6.4+10, 6.4+14.5 or 10+14.5) are planned to be applied to get enough quantity of H-like heavy ions. Since the main goal of this mach...
The Urgency for Peace in Teachings of John Paul II
Directory of Open Access Journals (Sweden)
Jerzy Lewandowski
2014-04-01
Full Text Available Peace has always been a topic of great importance. Its presence is desired by all nations and societies. It brings the world together in unity. John Paul II considered peace to be an integral part in creation of an independent and healthy society. Papal encyclicals and messages, intended to present the response of the teaching Church to problems that arise from time to time, often dwell on the principles that advocate peace. Since freedom and peace are in many cases a privilege for many nations, the mentioned pope commits himself to speak about the cruelty and evilness of wars and national conflicts. Pope John Paul II denounces intolerance as denial of freedom for many people, and consequently a great threat to peace. The pope teaches that peace has its roots in the family. Yet, in many societies, the family is deprived of the utmost importance that it certainly deserves. Without the adequate means for a decent livelihood, families can experience hardship in committing themselves to promote solidarity and a proper social fabric worthy of human dignity. For John Paul II, a nation’s freedom and peace are safeguarded and promoted through particular attention and a much-devoted effort by strong and healthy families.
Paul Goodman Redux: Education as Apprenticed Anarchism
Holowchak, M. Andrew
2010-01-01
When talk of philosophy of pedagogy comes up today, it is common to hear the names of Aristotle, Thomas Jefferson, John Dewey, or Paulo Freire, but the name of Paul Goodman, who campaigned vigorously for pedagogical reform much of his life, is seldom mentioned. In spite of neglect of his work, Goodman had much to say on pedagogical practice that…
Electron Fermi acceleration in collapsing magnetic traps: Computational and analytical models
International Nuclear Information System (INIS)
Gisler, G.; Lemons, D.
1990-01-01
The authors consider the heating and acceleration of electrons trapped on magnetic field lines between approaching magnetic mirrors. Such a collapsing magnetic trap and consequent electron energization can occur whenever a curved (or straight) flux tube drifts into a relatively straight (or curved) perpendicular shock. The relativistic, three-dimensional, collisionless test particle simulations show that an initial thermal electron distribution is bulk heated while a few individual electrons are accelerated to many times their original energy before they escape the trap. Upstream field-aligned beams and downstream pancake distributions perpendicular to the field are predicted. In the appropriate limit the simulation results agree well with a nonrelativistic analytic model of the distribution of escaping electrons which is based on the first adiabatic invariant and energy conservation between collisions with the mirrors. Space science and astrophysical applications are discussed
A Comparative Study of Saint Paul and Fakhri Razi on Faith
Directory of Open Access Journals (Sweden)
Ghorban Elmi
2014-09-01
Full Text Available Faith has a central place in Abrahamic religions. Jewish, Christian and Moslem thinkers have conducted several studies of the notion of faith and offered different ideas. Fakhri Razi and Saint Paul, two thinkers from Islamic and Christian religious traditions, have commented on the matter at length and these comments and ideas are studied in this essay. Paul the Apostle (died 64 AD is the most famous and influential Christian figure and is known as the second founder of Christianity. He has an indispensable role in formulating Christian doctrines. At first, he was a Jew and after the revelation of Jesus, converted to Christianity and dedicated himself to evangelism. The only credible reports and first hand sources about the lives and beliefs of Paul are the Acts of the Apostles and his letters and epistles in the Bible. The background of the debate on faith should be sought for in the Old Testament. In the Old Testament, belief means trusting in God, relying on Him, and recognizing and acknowledging the special relationship that God has established with Israel. In the New Testament, belief has a significant position too. Faith in the New Testament is more epistemic and cognitive and means certain belief and conviction. According to Paul faith is the basic principle of Christianity and outstanding feature of Christians and the main cause of salvation. In the early Christianity, Paul offers the most extensive and most profound exposition of faith. In defining faith, Paul uses Greek word «pistis» which means confidence, faith and trust. In definition of faith, he says: "Faith is the confidence that what we hope will be, and faith is the certainty of what we believe, although we are not able to see them "(Hebrews, 11/1. He mentions Abraham as a distinguished example for introducing true faith and faithful. Faith in Jesus means to trust or have confidence in Jesus Christ. According to Paul, faith is based on hope in things which have
A Comparative Study of Saint Paul and Fakhri Razi on Faith
Directory of Open Access Journals (Sweden)
Hamed Nazarpour najafabadi
2014-08-01
Full Text Available Faith has a central place in Abrahamic religions. Jewish, Christian and Moslem thinkers have conducted several studies of the notion of faith and offered different ideas. Fakhri Razi and Saint Paul, two thinkers from Islamic and Christian religious traditions, have commented on the matter at length and these comments and ideas are studied in this essay. Paul the Apostle (died 64 AD is the most famous and influential Christian figure and is known as the second founder of Christianity. He has an indispensable role in formulating Christian doctrines. At first, he was a Jew and after the revelation of Jesus, converted to Christianity and dedicated himself to evangelism. The only credible reports and first hand sources about the lives and beliefs of Paul are the Acts of the Apostles and his letters and epistles in the Bible. The background of the debate on faith should be sought for in the Old Testament. In the Old Testament, belief means trusting in God, relying on Him, and recognizing and acknowledging the special relationship that God has established with Israel. In the New Testament, belief has a significant position too. Faith in the New Testament is more epistemic and cognitive and means certain belief and conviction. According to Paul faith is the basic principle of Christianity and outstanding feature of Christians and the main cause of salvation. In the early Christianity, Paul offers the most extensive and most profound exposition of faith. In defining faith, Paul uses Greek word «pistis» which means confidence, faith and trust. In definition of faith, he says: "Faith is the confidence that what we hope will be, and faith is the certainty of what we believe, although we are not able to see them "(Hebrews, 11/1. He mentions Abraham as a distinguished example for introducing true faith and faithful. Faith in Jesus means to trust or have confidence in Jesus Christ. According to Paul, faith is based on hope in things which have
Paul Hillieri koor tõi Eestile Grammy / Immo Mihkelson
Mihkelson, Immo, 1959-
2007-01-01
2006. aasta septembris ilmunud plaadifirma Harmonia Mundi heliplaadi Arvo Pärt "Da Pacem", esitab Eesti Filharmoonia Kammerkoor, dirigent Paul Hillier Grammy võidust. Eesti Filharmoonia Kammerkoori koostööst USA plaadirmaga Harmonia Mundi. Grammy võitnud heliplaadist
Influence of local capillary trapping on containment system effectiveness
Energy Technology Data Exchange (ETDEWEB)
Bryant, Steven [University Of Texas At Austin, Austin, TX (United States). Center for Petroleum and Geosystems Engineering
2014-03-31
Immobilization of CO2 injected into deep subsurface storage reservoirs is a critical component of risk assessment for geologic CO2 storage (GCS). Local capillary trapping (LCT) is a recently established mode of immobilization that arises when CO2 migrates due to buoyancy through heterogeneous storage reservoirs. This project sought to assess the amount and extent of LCT expected in storage formations under a range of injection conditions, and to confirm the persistence of LCT if the seal overlying the reservoir were to lose its integrity. Numerical simulation using commercial reservoir simulation software was conducted to assess the influence of injection. Laboratory experiments, modeling and numerical simulation were conducted to assess the effect of compromised seal integrity. Bench-scale (0.6 m by 0.6 m by 0.03 m) experiments with surrogate fluids provided the first empirical confirmation of the key concepts underlying LCT: accumulation of buoyant nonwetting phase at above residual saturations beneath capillary barriers in a variety of structures, which remains immobile under normal capillary pressure gradients. Immobilization of above-residual saturations is a critical distinction between LCT and the more familiar “residual saturation trapping.” To estimate the possible extent of LCT in a storage reservoir an algorithm was developed to identify all potential local traps, given the spatial distribution of capillary entry pressure in the reservoir. The algorithm assumes that the driving force for CO2 migration can be represented as a single value of “critical capillary entry pressure” Pc,entrycrit, such that cells with capillary entry pressure greater/less than Pc,entrycrit act as barriers/potential traps during CO2 migration. At intermediate values of Pc,entrycrit, the barrier regions become more laterally extensive in the reservoir
The LPCTrap for the measurement of the β- ν correlation in 6He
International Nuclear Information System (INIS)
Rodriguez, D.; Mery, A.; Darius, G.; Herbane, M.; Ban, G.; Delahaye, P.; Durand, D.; Flechard, X.; Labalme, M.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.
2005-01-01
The application of traps to precision measurements of the β-ν angular correlation coefficient a in nuclear β-decay is pursued by several laboratories world wide. Various nuclear transitions are addressed and different trap devices are used. At GANIL, a novel transparent Paul trap (LPCTrap) has been built downstream from the SPIRAL source to determine a in the pure Gamow-Teller decay of 6 He. This transition is driven by the axial-vector interaction. The forbidden tensor interaction may be observed through a precise measurement of a. The LPCTrap consists of an RFQ-Buncher, a transparent Paul trap, and the detection system. It is currently the only facility that uses a Paul trap with a novel geometry to perform high-precision nuclear physics experiments. All the elements have been tested and meet the requirements. In this contribution we give a short status report of the project underlining the highlights achieved so far. (orig.)
Feedback-controlled diffusion: From self-trapping to true self-avoiding walks
International Nuclear Information System (INIS)
Schulz, B.M.; Trimper, S.; Schulz, M.
2005-01-01
We study the asymptotic behavior of a Brownian particle under the influence of a dynamical feedback by numerical simulations and analytical considerations. The feedback is controlled by a memory coupling of strength λ. Whereas a negative memory strength yields a true self avoiding walk, a positive memory leads to a self-trapping of the particle. The localization is manifested by a constant mean square displacement in the long time limit which appears after an initial diffusive regime. The probability distribution function of the trapping distance shows an exponential decay. The numerical simulations are compared with an analytical modeling
Simulating the performance of a distance-3 surface code in a linear ion trap
Trout, Colin J.; Li, Muyuan; Gutiérrez, Mauricio; Wu, Yukai; Wang, Sheng-Tao; Duan, Luming; Brown, Kenneth R.
2018-04-01
We explore the feasibility of implementing a small surface code with 9 data qubits and 8 ancilla qubits, commonly referred to as surface-17, using a linear chain of 171Yb+ ions. Two-qubit gates can be performed between any two ions in the chain with gate time increasing linearly with ion distance. Measurement of the ion state by fluorescence requires that the ancilla qubits be physically separated from the data qubits to avoid errors on the data due to scattered photons. We minimize the time required to measure one round of stabilizers by optimizing the mapping of the two-dimensional surface code to the linear chain of ions. We develop a physically motivated Pauli error model that allows for fast simulation and captures the key sources of noise in an ion trap quantum computer including gate imperfections and ion heating. Our simulations showed a consistent requirement of a two-qubit gate fidelity of ≥99.9% for the logical memory to have a better fidelity than physical two-qubit operations. Finally, we perform an analysis of the error subsets from the importance sampling method used to bound the logical error rates to gain insight into which error sources are particularly detrimental to error correction.
Winjum, B. J.; Banks, J. W.; Berger, R. L.; Cohen, B. I.; Chapman, T.; Hittinger, J. A. F.; Rozmus, W.; Strozzi, D. J.; Brunner, S.
2012-10-01
We present results on the kinetic filamentation of finite-width nonlinear electron plasma waves (EPW). Using 2D simulations with the PIC code BEPS, we excite a traveling EPW with a Gaussian transverse profile and a wavenumber k0λDe= 1/3. The transverse wavenumber spectrum broadens during transverse EPW localization for small width (but sufficiently large amplitude) waves, while the spectrum narrows to a dominant k as the initial EPW width increases to the plane-wave limit. For large EPW widths, filaments can grow and destroy the wave coherence before transverse localization destroys the wave; the filaments in turn evolve individually as self-focusing EPWs. Additionally, a transverse electric field develops that affects trapped electrons, and a beam-like distribution of untrapped electrons develops between filaments and on the sides of a localizing EPW. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the Laboratory Research and Development Program at LLNL under project tracking code 12-ERD-061. Supported also under Grants DE-FG52-09NA29552 and NSF-Phy-0904039. Simulations were performed on UCLA's Hoffman2 and NERSC's Hopper.
Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator
Energy Technology Data Exchange (ETDEWEB)
Kirby, Neil; /SLAC
2009-10-30
Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped
Fundamental limit of light trapping in grating structures
Yu, Zongfu
2010-08-11
We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n 2, but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile’s symmetry on the absorption enhancement limit. Numerical simulations are applied to support the theory. Our findings provide general guidance for the design of grating structures for light-trapping solar cells.
Trapping a Knot into Tight Conformations by Intra-Chain Repulsions
Directory of Open Access Journals (Sweden)
Liang Dai
2017-02-01
Full Text Available Knots can occur in biopolymers such as DNA and peptides. In our previous study, we systematically investigated the effects of intra-chain interactions on knots and found that long-range repulsions can surprisingly tighten knots. Here, we use this knowledge to trap a knot into tight conformations in Langevin dynamics simulations. By trapping, we mean that the free energy landscape with respect to the knot size exhibits a potential well around a small knot size in the presence of long-range repulsions, and this potential can well lead to long-lived tight knots when its depth is comparable to or larger than thermal energy. We tune the strength of intra-chain repulsion such that a knot is weakly trapped. Driven by thermal fluctuations, the knot can escape from the trap and is then re-trapped. We find that the knot switches between tight and loose conformations—referred to as “knot breathing”. We use a Yukawa potential to model screened electrostatic interactions to explore the relevance of knot trapping and breathing in charged biopolymers. We determine the minimal screened length and the minimal strength of repulsion for knot trapping. We find that Coulomb-induced knot trapping is possible to occur in single-stranded DNA and peptides for normal ionic strengths.
Directory of Open Access Journals (Sweden)
Catherine Bernard
2006-12-01
Full Text Available Le photographe britannique Paul Graham (1956- ne jouit pas encore en France de la notoriété de son compatriote Martin Parr et on ne peut, par conséquent, que se féliciter de voir l’une de ses plus puissantes séries — American Night — représentée à la Galerie Les Filles du Calvaire.Connu, avec Parr, pour avoir profondément influencé la photo documentaire anglaise en la faisant passer à la couleur avec virulence, Graham a été révélé il y a une vingtaine d’années par une série d’images prises à...
Introduction: Reappraising Paul Feyerabend.
Brown, Matthew J; Kidd, Ian James
2016-06-01
This volume is devoted to a reappraisal of the philosophy of Paul Feyerabend. It has four aims. The first is to reassess his already well-known work from the 1960s and 1970s in light of contemporary developments in the history and philosophy of science. The second is to explore themes in his neglected later work, including recently published and previously unavailable writings. The third is to assess the contributions that Feyerabend can make to contemporary debate, on topics such as perspectivism, realism, and political philosophy of science. The fourth and final aim is to reconsider Feyerabend's place within the history of philosophy of science in the light of new scholarship. Copyright © 2015 Elsevier Ltd. All rights reserved.
Mobile trap algorithm for zinc detection using protein sensors
International Nuclear Information System (INIS)
Inamdar, Munish V.; Lastoskie, Christian M.; Fierke, Carol A.; Sastry, Ann Marie
2007-01-01
We present a mobile trap algorithm to sense zinc ions using protein-based sensors such as carbonic anhydrase (CA). Zinc is an essential biometal required for mammalian cellular functions although its intracellular concentration is reported to be very low. Protein-based sensors like CA molecules are employed to sense rare species like zinc ions. In this study, the zinc ions are mobile targets, which are sought by the mobile traps in the form of sensors. Particle motions are modeled using random walk along with the first passage technique for efficient simulations. The association reaction between sensors and ions is incorporated using a probability (p 1 ) upon an ion-sensor collision. The dissociation reaction of an ion-bound CA molecule is modeled using a second, independent probability (p 2 ). The results of the algorithm are verified against the traditional simulation techniques (e.g., Gillespie's algorithm). This study demonstrates that individual sensor molecules can be characterized using the probability pair (p 1 ,p 2 ), which, in turn, is linked to the system level chemical kinetic constants, k on and k off . Further investigations of CA-Zn reaction using the mobile trap algorithm show that when the diffusivity of zinc ions approaches that of sensor molecules, the reaction data obtained using the static trap assumption differ from the reaction data obtained using the mobile trap formulation. This study also reveals similar behavior when the sensor molecule has higher dissociation constant. In both the cases, the reaction data obtained using the static trap formulation reach equilibrium at a higher number of complex molecules (ion-bound sensor molecules) compared to the reaction data from the mobile trap formulation. With practical limitations on the number sensors that can be inserted/expressed in a cell and stochastic nature of the intracellular ionic concentrations, fluorescence from the number of complex sensor molecules at equilibrium will be the measure
The value of children in the context of the family in Java / by Paul A. Meyer
Meyer, Paul A
1987-01-01
... The value of children in the context of the family in Java [microform] / by Paul A. Meyer. The value of children in the context of the family in Java by Paul A. Meyer. The value of children in the context of the family in Java ...
Influence of modulation method on using LC-traps with single-phase voltage source converters
DEFF Research Database (Denmark)
Wang, Xiongfei; Min, Huang; Bai, Haofeng
2015-01-01
The switching-frequency LC-trap filter has recently been employed with high-order passive filters for Voltage Source Inverters (VSIs). This paper investigates the influence of modulation method on using the LC-traps with single-phase VSIs. Two-level (bipolar) and three-level (unipolar) modulations...... that include phase distortion and alternative phase opposition distortion methods are analyzed. Harmonic filtering performances of four LC-trap-based filters with different locations of LC-traps are compared. It is shown that the use of parallel-LC-traps in series with filter inductors, either grid...... or converter side, has a worse harmonic filtering performance than using series-LC-trap in the shunt branch. Simulations and experimental results are presented for verifications....
Trapping in irradiated p-on-n silicon sensors at fluences anticipated at the HL-LHC outer tracker
Adam, W.; Dragicevic, M.; Friedl, M.; Fruehwirth, R.; Hoch, M.; Hrubec, J.; Krammer, M.; Treberspurg, W.; Waltenberger, W.; Alderweireldt, S.; Beaumont, W.; Janssen, X.; Luyckx, S.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Barria, P.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Grebenyuk, A.; Lenzi, Th.; Leonard, A.; Maerschalk, Th.; Mohammadi, A.; Pernie, L.; Randle-Conde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Zeid, S.Abu; Blekman, F.; De Bruyn, I.; D'Hondt, J.; Daci, N.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels; Olbrechts, A.; Python, Q.; Tavernier, S.; Van Mulders, P.; Van Onsem, G.; Van Parijs, I.; Strom, D.A.; Basegmez, S.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; De Callatay, B.; Delaere, C.; Pree, T.Du; Forthomme, L.; Giammanco, A.; Hollar, J.; Jez, P.; Michotte, D.; Nuttens, C.; Perrini, L.; Pagano, D.; Quertenmont, L.; Selvaggi, M.; Marono, M.Vidal; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G.H.; Harkonen, J.; Lampen, T.; Luukka, P.R.; Maenpaa, T.; Peltola, T.; Tuominen, E.; Tuovinen, E.; Eerola, P.; Tuuva, T.; Beaulieu, G.; Boudoul, G.; Combaret, C.; Contardo, D.; Gallbit, G.; Lumb, N.; Mathez, H.; Mirabito, L.; Perries, S.; Sabes, D.; Vander Donckt, M.; Verdier, P.; Viret, S.; Zoccarato, Y.; Agram, J.L.; Conte, E.; Fontaine, J.Ch.; Andrea, J.; Bloch, D.; Bonnin, C.; Brom, J.M.; Chabert, E.; Charles, L.; Goetzmann, Ch.; Gross, L.; Hosselet, J.; Mathieu, C.; Richer, M.; Skovpen, K.; Pistone, C.; Fluegge, G.; Kuensken, A.; Geisler, M.; Pooth, O.; Stahl, A.; Autermann, C.; Edelhoff, M.; Esser, H.; Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Pierschel, G.; Preuten, M.; Raupach, F.; Sammet, J.; Schael, S.; Schwering, G.; Wittmer, B.; Wlochal, M.; Zhukov, V.; Bartosik, N.; Behr, J.; Burgmeier, A.; Calligaris, L.; Dolinska, G.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Fluke, G.; Garcia, J.Garay; Gizhko, A.; Hansen, K.; Harb, A.; Hauk, J.; Kalogeropoulos, A.; Kleinwort, C.; Korol, I.; Lange, W.; Lohmann, W.; Mankel, R.; Maser, H.; Mittag, G.; Muhl, C.; Mussgiller, A.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Schroeder, M.; Seitz, C.; Spannagel, S.; Zuber, A.; Biskop, H.; Blobel, V.; Buhmann, P.; Centis-Vignali, M.; Draeger, A.R.; Erfle, J.; Garutti, E.; Haller, J.; Hoffmann, M.; Junkes, A.; Lapsien, T.; Mattig, S.; Matysek, M.; Perieanu, A.; Poehlsen, J.; Poehlsen, T.; Scharf, Ch.; Schleper, P.; Schmidt, A.; Sola, V.; Steinbruck, G.; Wellhausen, J.; Barvich, T.; Barth, Ch.; Boegelspacher, F.; De Boer, W.; Butz, E.; Casele, M.; Colombo, F.; Dierlamm, A.; Eber, R.; Freund, B.; Hartmann, F.; Hauth, Th.; Heindl, S.; Hoffmann, K.H.; Husemann, U.; Kornmeyer, A.; Mallows, S.; Muller, Th.; Nuernberg, A.; Printz, M.; Simonis, H.J.; Steck, P.; Weber, M.; Weiler, Th.; Bhardwaj, A.; Kumar, A.; Ranjan, K.; Bakhshiansohl, H.; Behnamian, H.; Khakzad, M.; Naseri, M.; Cariola, P.; De Robertis, G.; Fiore, L.; Franco, M.; Loddo, F.; Sala, G.; Silvestris, L.; Creanza, D.; De Palma, M.; Maggi, G.; My, S.; Selvaggi, G.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Giordano, F.; Di Mattia, A.; Potenza, R.; Saizu, M.A.; Tricomi, A.; Tuve, C.; Barbagli, G.; Brianzi, M.; Ciaranfi, R.; Civinini, C.; Gallo, E.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Ciulli, V.; D'Alessandro, R.; Gonzi, S.; Gori, V.; Focardi, E.; Lenzi, P.; Scarlini, E.; Tropiano, A.; Viliani, L.; Ferro, F.; Robutti, E.; Lo Vetere, M.; Gennai, S.; Malvezzi, S.; Menasce, D.; Moroni, L.; Pedrini, D.; Dinardo, M.; Fiorendi, S.; Manzoni, R.A.; Azzi, P.; Bacchetta, N.; Bisello, D.; Dall'Osso, M.; Dorigo, T.; Giubilato, P.; Pozzobon, N.; Tosi, M.; Zucchetta, A.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Nodari, B.; Re, V.; Traversi, G.; Comotti, D.; Ratti, L.; Bilei, G.M.; Bissi, L.; Checcucci, B.; Magalotti, D.; Menichelli, M.; Saha, A.; Servoli, L.; Storchi, L.; Biasini, M.; Conti, E.; Ciangottini, D.; Fano, L.; Lariccia, P.; Mantovani, G.; Passeri, D.; Placidi, P.; Salvatore, M.; Santocchia, A.; Solestizi, L.A.; Spiezia, A.; Androsov, K.; Azzurri, P.; Arezzini, S.; Bagliesi, G.; Basti, A.; Boccali, T.; Bosi, F.; Castaldi, R.; Ciampa, A.; Ciocci, M.A.; Dell'Orso, R.; Fedi, G.; Giassi, A.; Grippo, M.T.; Lomtadze, T.; Magazzu, G.; Mazzoni, E.; Minuti, M.; Moggi, A.; Moon, C.S.; Morsani, F.; Palla, F.; Palmonari, F.; Raffaelli, F.; Savoy-Navarro, A.; Serban, A.T.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Martini, L.; Messineo, A.; Rizzi, A.; Tonelli, G.; Calzolari, F.; Donato, S.; Fiori, F.; Ligabue, F.; Vernieri, C.; Demaria, N.; Rivetti, A.; Bellan, R.; Casasso, S.; Costa, M.; Covarelli, R.; Migliore, E.; Monteil, E.; Musich, M.; Pacher, L.; Ravera, F.; Romero, A.; Solano, A.; Trapani, P.; Jaramillo Echeverria, R.; Fernandez, M.; Gomez, G.; Moya, D.; F. Gonzalez Sanchez, J.; Munoz Sanchez, F.J.; Vila, I.; Virto, A.L.; Abbaneo, D.; Ahmed, I.; Albert, E.; Auzinger, G.; Berruti, G.; Bianchi, G.; Blanchot, G.; Breuker, H.; Ceresa, D.; Christiansen, J.; Cichy, K.; Daguin, J.; D'Alfonso, M.; D'Auria, A.; Detraz, S.; De Visscher, S.; Deyrail, D.; Faccio, F.; Felici, D.; Frank, N.; Gill, K.; Giordano, D.; Harris, P.; Honma, A.; Kaplon, J.; Kornmayer, A.; Kottelat, L.; Kovacs, M.; Mannelli, M.; Marchioro, A.; Marconi, S.; Martina, S.; Mersi, S.; Michelis, S.; Moll, M.; Onnela, A.; Pakulski, T.; Pavis, S.; Peisert, A.; Pernot, J.F.; Petagna, P.; Petrucciani, G.; Postema, H.; Rose, P.; Rzonca, M.; Stoye, M.; Tropea, P.; Troska, J.; Tsirou, A.; Vasey, F.; Vichoudis, P.; Verlaat, B.; Zwalinski, L.; Bachmair, F.; Becker, R.; Bani, L.; di Calafiori, D.; Casal, B.; Djambazov, L.; Donega, M.; Dunser, M.; Eller, P.; Grab, C.; Hits, D.; Horisberger, U.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Perrozzi, L.; Roeser, U.; Rossini, M.; Starodumov, A.; Takahashi, M.; Wallny, R.; Amsler, C.; Bosiger, K.; Caminada, L.; Canelli, F.; Chiochia, V.; De Cosa, A.; Galloni, C.; Hreus, T.; Kilminster, B.; Lange, C.; Maier, R.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Taroni, S.; Yang, Y.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Kaestli, H.C.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Streuli, S.; Chen, P.H.; Dietz, C.; Grundler, U.; Hou, W.S.; Lu, R.S.; Moya, M.; Wilken, R.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Jacob, J.; El Nasr-Storey, S.Seif; Cole, J.; Hobson, P.; Leggat, D.; Reid, I.D.; Teodorescu, L.; Bainbridge, R.; Dauncey, P.; Fulcher, J.; Hall, G.; Magnan, A.M.; Pesaresi, M.; Raymond, D.M.; Uchida, K.; Coughlan, J.A.; Harder, K.; Ilic, J.; Tomalin, I.R.; Garabedian, A.; Heintz, U.; Narain, M.; Nelson, J.; Sagir, S.; Speer, T.; Swanson, J.; Tersegno, D.; Watson-Daniels, J.; Chertok, M.; Conway, J.; Conway, R.; Flores, C.; Lander, R.; Pellett, D.; Ricci-Tam, F.; Squires, M.; Thomson, J.; Yohay; Burt, K.; Ellison, J.; Hanson, G.; Malberti, M.; Olmedo, M.; Cerati, G.; Sharma, V.; Vartak, A.; Yagil, A.; Della Porta, G.Zevi; Dutta, V.; Gouskos, L.; Incandela, J.; Kyre, S.; McColl, N.; Mullin, S.; White, D.; Cumalat, J.P.; Ford, W.T.; Gaz, A.; Krohn, M.; Stenson, K.; Wagner, S.R.; Baldin, B.; Bolla, G.; Burkett, K.; Butler, J.; Cheung, H.; Chramowicz, J.; Christian, D.; Cooper, W.E.; Deptuch, G.; Derylo, G.; Gingu, C.; Gruenendahl, S.; Hasegawa, S.; Hoff, J.; Howell, J.; Hrycyk, M.; Jindariani, S.; Johnson, M.; Jung, A.; Joshi, U.; Kahlid, F.; Lei, C.M.; Lipton, R.; Liu, T.; Los, S.; Matulik, M.; Merkel, P.; Nahn, S.; Prosser, A.; Rivera, R.; Shenai, A.; Spiegel, L.; Tran, N.; Uplegger, L.; Voirin, E.; Yin, H.; Adams, M.R.; Berry, D.R.; Evdokimov, A.; Evdokimov, O.; Gerber, C.E.; Hofman, D.J.; Kapustka, B.K.; O'Brien, C.; Sandoval Gonzalez, D.I.; Trauger, H.; Turner, P.; Parashar, N.; Stupak, J.; I.I.I.; Bortoletto, D.; Bubna, M.; Hinton, N.; Jones, M.; Miller, D.H.; Shi, X.; Tan, P.; Baringer, P.; Bean, A.; Benelli, G.; Gray, J.; Majumder, D.; Noonan, D.; Sanders, S.; Stringer, R.; Ivanov, A.; Makouski, M.; Skhirtladze, N.; Taylor, R.; Anderson, I.; Fehling, D.; Gritsan, A.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Acosta, J.G.; Cremaldi, L.M.; Oliveros, S.; Perera, L.; Summers, D.; Bloom, K.; Bose, S.; Claes, D.R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Meier, F.; Monroy, J.; Hahn, K.; Sevova, S.; Sung, K.; Trovato, M.; Bartz, E.; Duggan, D.; Halkiadakis, E.; Lath, A.; Park, M.; Schnetzer, S.; Stone, R.; Walker, M.; Malik, S.; Mendez, H.; Ramirez Vargas, J.E.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Kaufman, G.; Mirman, N.; Ryd, A.; Salvati, E.; Skinnari, L.; Thom, J.; Thompson, J.; Tucker, J.; Winstrom, L.; Akgun, B.; Ecklund, K.M.; Nussbaum, T.; Zabel, J.; Betchart, B.; Demina, R.; Hindrichs, O.; Petrillo, G.; Eusebi, R.; Osipenkov, I.; Perloff, A.; Ulmer, K.A.; Delannoy, A.G.; D'Angelo, P.; Johns, W.
2016-04-22
The degradation of signal in silicon sensors is studied under conditions expected at the CERN High-Luminosity LHC. 200 $\\mu$m thick n-type silicon sensors are irradiated with protons of different energies to fluences of up to $3 \\cdot 10^{15}$ neq/cm$^2$. Pulsed red laser light with a wavelength of 672 nm is used to generate electron-hole pairs in the sensors. The induced signals are used to determine the charge collection efficiencies separately for electrons and holes drifting through the sensor. The effective trapping rates are extracted by comparing the results to simulation. The electric field is simulated using Synopsys device simulation assuming two effective defects. The generation and drift of charge carriers are simulated in an independent simulation based on PixelAV. The effective trapping rates are determined from the measured charge collection efficiencies and the simulated and measured time-resolved current pulses are compared. The effective trapping rates determined for both electrons and holes...
Justice John Paul Stevens and the Erotic Boomerang.
Lieberman, Marc
Justice John Paul Stevens of the United States Supreme Court has ruled on obscenity cases in seven instances since his appointment. His rulings reveal that he regards obscenity as a nuisance rather than as a danger threatening to undermine the nation's morality, that he supports a nationwide standard to adjudicate obscenity cases, and that he…
Macroscopic rate equation modeling of trapping/detrapping of hydrogen isotopes in tungsten materials
Energy Technology Data Exchange (ETDEWEB)
Hodille, E.A., E-mail: etienne.hodille@cea.fr [CEA, IRFM, F-13108 Saint Paul lez Durance (France); Bonnin, X. [LSPM-CNRS, Université Paris 13, Sorbonne Paris Cité, F-93430 Villetaneuse (France); Bisson, R.; Angot, T. [Aix-Marseille Université, PIIM, CNRS, UMR 7345, 13397 Marseille (France); Becquart, C.S. [Université Lille I, UMET, UMR 8207, 59655 Villeneuve d’Ascq cédex France (France); Layet, J.M. [Aix-Marseille Université, PIIM, CNRS, UMR 7345, 13397 Marseille (France); Grisolia, C. [CEA, IRFM, F-13108 Saint Paul lez Durance (France)
2015-12-15
Relevant parameters for trapping of Hydrogen Isotopes (HIs) in polycrystalline tungsten are determined with the MHIMS code (Migration of Hydrogen Isotopes in MaterialS) which is used to reproduce Thermal Desorption Spectrometry experiments. Three types of traps are found: two intrinsic traps (detrapping energy of 0.87 eV and 1.00 eV) and one extrinsic trap created by ion irradiation (detrapping energy of 1.50 eV). Then MHIMS is used to simulate HIs retention at different fluences and different implantation temperatures. Simulation results agree well with experimental data. It is shown that at 300 K the retention is limited by diffusion in the bulk. For implantation temperatures above 500 K, the retention is limited by trap creation processes. Above 600 K, the retention drops by two orders of magnitude as compared to the retention at 300 K. With the determined detrapping energies, HIs outgassing at room temperature is predicted. After ions implantation at 300 K, 45% of the initial retention is lost to vacuum in 300 000 s while during this time the remaining trapped HIs diffuse twice as deep into the bulk. - Highlights: • Code development to solve numerically the model equations of diffusion and trapping of hydrogen in metals. • Parametrization of the model trapping parameters (detrapping energies and density): fitting of experimental TDS spectrum. • Confrontation model/experiment: evolution of retention with fluence and implantation temperature. • Investigation of period of rest between implantation and TDS on retention and depth profile.
Effects of oxide traps, interface traps, and ''border traps'' on metal-oxide-semiconductor devices
International Nuclear Information System (INIS)
Fleetwood, D.M.; Winokur, P.S.; Reber, R.A. Jr.; Meisenheimer, T.L.; Schwank, J.R.; Shaneyfelt, M.R.; Riewe, L.C.
1993-01-01
We have identified several features of the 1/f noise and radiation response of metal-oxide-semiconductor (MOS) devices that are difficult to explain with standard defect models. To address this issue, and in response to ambiguities in the literature, we have developed a revised nomenclature for defects in MOS devices that clearly distinguishes the language used to describe the physical location of defects from that used to describe their electrical response. In this nomenclature, ''oxide traps'' are simply defects in the SiO 2 layer of the MOS structure, and ''interface traps'' are defects at the Si/SiO 2 interface. Nothing is presumed about how either type of defect communicates with the underlying Si. Electrically, ''fixed states'' are defined as trap levels that do not communicate with the Si on the time scale of the measurements, but ''switching states'' can exchange charge with the Si. Fixed states presumably are oxide traps in most types of measurements, but switching states can either be interface traps or near-interfacial oxide traps that can communicate with the Si, i.e., ''border traps'' [D. M. Fleetwood, IEEE Trans. Nucl. Sci. NS-39, 269 (1992)]. The effective density of border traps depends on the time scale and bias conditions of the measurements. We show the revised nomenclature can provide focus to discussions of the buildup and annealing of radiation-induced charge in non-radiation-hardened MOS transistors, and to changes in the 1/f noise of MOS devices through irradiation and elevated-temperature annealing
Energy Technology Data Exchange (ETDEWEB)
Brankov, Vladimir [Laboratory for Reactor Physics and Systems Behaviour at the Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Swiss Federal Institute of Technology Lausanne (EPFL), Route Cantonale, 1015 Lausanne (Switzerland); Khvostov, Grigori; Mikityuk, Konstantin [Laboratory for Reactor Physics and Systems Behaviour at the Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Pautz, Andreas [Laboratory for Reactor Physics and Systems Behaviour at the Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Swiss Federal Institute of Technology Lausanne (EPFL), Route Cantonale, 1015 Lausanne (Switzerland); Restani, Renato; Abolhassani, Sousan [Laboratory for Nuclear Materials at the Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Ledergerber, Guido [Kernkraftwerk Leibstadt, 5325 Leibstadt (Switzerland); Wiesenack, Wolfgang [Institutt for Energiteknikk - OECD Halden Reactor Project, Os Allé 5, 1777 Halden (Norway)
2016-08-15
Highlights: • Explanation for the scatter in measured fission gas release in high-BU BWR fuel rods. • Partial fuel-clad bond layer formation in high-BU BWR fuel. • Hypothesis for fission gas trapping facilitated by the pellet-cladding bond layer. • Correlation between burnup asymmetry and the quantity of trapped fission gas. • Implications of the trapped FG in LOCA transient. - Abstract: The first part of the paper presents results of a numerical analysis of the fuel behavior during base irradiation in the Kernkraftwerk Leibstadt Boiling Water Reactor (KKL BWR) using EPRI’s FALCON code coupled to GRSW-A – an advanced model for fuel swelling and fission gas release. Post-irradiation examinations conducted at the Paul Scherrer Institute’s (PSI) hot laboratory gave evidence of a distinct circumferential non-uniformity of local burnup at pellet surfaces. For several fuel samples, intact pellet-cladding bonding areas on the high burnup sides of the pellets at high burnup above ∼70 MWd/kgU were observed. It is hypothesized that a part of the fission gases, which are expected to be released by those areas, can be trapped and do not reach the rod plenum. In this paper, a simple approach to modeling of fission gas trapping is employed which reveals a potential correlation between the position of the rod within the fuel assembly (and therefore the degree of circumferential burnup non-uniformity) and the degree of fission gas trapping. A model is suggested to correlate the amount of locally trapped gas with the integral of the local contact pressure and the degree of circumferential burnup non-uniformity. The model is calibrated with available measurements of FGR from rod puncturing at the level of the plenums. In future work, the hypothesis about the axial distribution of trapped fission gas will be extrapolated to the Loss-Of-Coolant Accident (LOCA) analysis as an attempt to explain the fission gas release observed in some samples fabricated from
Inverse scaling trends for charge-trapping-induced degradation of FinFETs performance
Amoroso, Salvatore Maria; Georgiev, Vihar P.; Gerrer, Louis; Towie, Ewan; Wang, Xingsheng; Riddet, Craig; Brown, Andrew Robert; Asenov, Asen
2014-01-01
In this paper, we investigate the impact of a single discrete charge trapped at the top oxide interface on the performance of scaled nMOS FinFET transistors. The charge-trapping-induced gate voltage shift is simulated as a function of the device scaling and for several regimes of conduction-from subthreshold to ON-state. Contrary to what is expected for planar MOSFETs, we show that the trap impact decreases with scaling down the FinFET size and the applied gate voltage. By comparing drift-dif...
Nonlinear Simulations of Trapped Electron Mode Turbulence in Low Magnetic Shear Stellarators
Faber, B. J.; Pueschel, M. J.; Terry, P. W.; Hegna, C. C.
2017-10-01
Optimized stellarators, like the Helically Symmetric eXperiment (HSX), often operate with small global magnetic shear to avoid low-order rational surfaces and magnetic islands. Nonlinear, flux-tube gyrokinetic simulations of density-gradient-driven Trapped Electron Mode (TEM) turbulence in HSX shows two distinct spectral fluctuation regions: long-wavelength slab-like TEMs localized by global magnetic shear that extend along field lines and short-wavelength TEMs localized by local magnetic shear to a single helical bad curvature region. The slab-like TEMs require computational domains significantly larger than one poloidal turn and are computationally expensive, making turbulent optimization studies challenging. A computationally more efficient, zero-average-magnetic-shear approximation is shown to sufficiently describe the relevant nonlinear physics and replicate finite-shear computations, and can be exploited in quasilinear models based on linear gyrokinetics as a feasible optimization tool. TEM quasilinear heat fluxes are computed with the zero-shear approximation and compared to experimentally-relevant nonlinear gyrokinetic TEM heat fluxes for HSX. Research supported by U.S. DoE Grants DE-FG02-99ER54546, DE-FG02-93ER54222 and DE-FG02-89ER53291.
A model to optimize trap systems used for small mammal (Rodentia, Insectivora density estimates
Directory of Open Access Journals (Sweden)
Damiano Preatoni
1997-12-01
Full Text Available Abstract The environment found in the upper and lower Padane Plain and the adjoining hills isn't very homogeneous. In fact it is impossible to find biotopes extended enough to satisfy the necessary criteria for density estimate of small mammals based on the Removal method. This limitation has been partially overcome by adopting a reduced grid, counting 39 traps whose spacing depends on the studied species. Aim of this work was to verify - and eventually measure - the efficiency of a sampling method based on a "reduced" number of catch points. The efficiency of 18 trapping cycles, realized from 1991 to 1993, was evaluated as percent bias. For each of the trapping cycles, 100 computer simulations were performed, so obtaining a Monte-Carlo estimate of bias in density values. Then later, the efficiency of different trap arrangements was examined by varying the criteria. The numbers of traps ranged from 9 to 49, with trap spacing varying from 5 to 15 m and a trapping period duration from 5 to 9 nights. In this way an optimal grid system was found both for dimensions and time duration. The simulation processes involved, as a whole, 1511 different grid types, for 11347 virtual trapping cycles. Our results indicate that density estimates based on "reduced" grids are affected by an average -16% bias, that is an underestimate, and that an optimally sized grid must consist of 6x6 traps square, with about 8.7 m spacing. and be in operation for 7 nights.
The command to love the neighbour in Paul and the Synoptics
Directory of Open Access Journals (Sweden)
Heinz A. Hiestermann
2016-03-01
Full Text Available When sayings of Jesus are compared between the Pauline letters and the Synoptic Gospels in an attempt to locate parallels, Galatians 5:14 and Romans 13:8�10 have frequently been put forward as possible parallels to the Synoptic renditions of the great commandment of Mark 12:28�34 (Mt 22:34�40; Lk 10:25�28. These Pauline and Synoptic texts all contain the command to love the neighbour, but the Synoptic texts have added the command to love God to the command to love the neighbour. Paul never quoted the great commandment. Consequently, a relationship between the verses is normally rejected. However, not all possibilities have been explored. In the search for parallels between Pauline and Synoptic Jesus traditions it has been overlooked that Paul and Matthew render the command to love the neighbour more than once. Matthew delivers the command to love the neighbour three times. Only once he has connected it to the command to love God. Matthew renders the single command to love the neighbour twice, resembling the Pauline use of the command. Using the criteria for validating parallels between Pauline and Synoptic Jesus traditions, including verbal agreement and the unique use of the command to love the neighbour by Paul and Matthew, it is argued that a connection between Romans 13:9 and Matthew 19:18�19 is likely.Intradisciplinary and/or interdisciplinary implications: The research explores the use of Leviticus 19:18b by the New Testament authors. It is argued that the command to love the neighbour was given high prominence in the early church, as it was used by the Synoptic authors and by Paul to summarise Jesus� ethical teachings.
Simulation of lean NOx trap performance with microkinetic chemistry and without mass transfer.
Energy Technology Data Exchange (ETDEWEB)
Larson, Rich; Daw, C. Stuart (Oak Ridge National Laboratory, Knoxville, TN); Pihl, Josh A. (Oak Ridge National Laboratory, Knoxville, TN); Chakravarthy, V. Kalyana (Oak Ridge National Laboratory, Knoxville, TN)
2011-08-01
A microkinetic chemical reaction mechanism capable of describing both the storage and regeneration processes in a fully formulated lean NO{sub x} trap (LNT) is presented. The mechanism includes steps occurring on the precious metal, barium oxide (NO{sub x} storage), and cerium oxide (oxygen storage) sites of the catalyst. The complete reaction set is used in conjunction with a transient plug flow reactor code to simulate not only conventional storage/regeneration cycles with a CO/H{sub 2} reductant, but also steady flow temperature sweep experiments that were previously analyzed with just a precious metal mechanism and a steady state code. The results show that NO{sub x} storage is not negligible during some of the temperature ramps, necessitating a re-evaluation of the precious metal kinetic parameters. The parameters for the entire mechanism are inferred by finding the best overall fit to the complete set of experiments. Rigorous thermodynamic consistency is enforced for parallel reaction pathways and with respect to known data for all of the gas phase species involved. It is found that, with a few minor exceptions, all of the basic experimental observations can be reproduced with these purely kinetic simulations, i.e., without including mass-transfer limitations. In addition to accounting for normal cycling behavior, the final mechanism should provide a starting point for the description of further LNT phenomena such as desulfation and the role of alternative reductants.
Effect of the interaction among traps on the shape of thermoluminescence glow curves
International Nuclear Information System (INIS)
Marcazzo, J.; Santiago, M.; Spano, F.; Lester, M.; Ortega, F.; Molina, P.; Caselli, E.
2007-01-01
The effect of the interaction among traps on the structure of thermoluminescence glow curves has been investigated by generating numerically simulated glow curves for a wide range of trap parameters. The results reported in this paper provide useful insights which assist in the analysis of experimental glow curves. The most important result shows that it is incorrect to assume beforehand that each peak is related to a specific trapping state. The validity of the quasiequilibrium approximation is briefly discussed
Paul, military imagery and social disadvantage | Punt | Acta ...
African Journals Online (AJOL)
In the past, attention for the social position or standing of the early Jesus followers was overrun by concerns for the theological and religious dimensions of those communities. The role of the Roman Empire and the impact of its military forces on the lives of people have generated even less attention. Paul's use of military ...
Don't think about blue elephants! / Paul Hanley ; interv. Alina Lisina
Hanley, Paul
2005-01-01
"Guerrilla marketing'i" (partisani turundus) - hoolikalt kavandatud ja alternatiivseid kanaleid kasutav ebatraditsiooniline turundustegevus - tutvustus. Lisad: Paul Hanley; GM müüdid; 15 Guerrilla turunduse saladust
Paul Hill d/b/a Alternative Energy Windows and Siding
Paul Hill d/b/a Alternative Energy Windows and Siding (the Company) is located in Concord, New Hampshire. The settlement involves renovation activities conducted at property constructed prior to 1978, located in Concord, New Hampshire.
Trapped Mode Study For A Rotatable Collimator Design For The LHC Upgrade
Energy Technology Data Exchange (ETDEWEB)
Xiao, Liling; Ng, Cho-Kuen; Smith, Jeffery Claiborne; Caspers, Fritz; /SLAC /CERN
2009-06-23
A rotatable collimator is proposed for the LHC phase II collimation upgrade. When the beam crosses the collimator, it will excite trapped modes that can contribute to the beam energy loss and power dissipation on the vacuum chamber wall. Transverse trapped modes can also generate transverse kicks on the beam and may thus affect the beam quality. In this paper, the parallel eigensolver code Omega3P is used to search for all the trapped modes below 2 GHz in two collimator designs, one with rectangular and the other with circular vacuum chamber. It is found that the longitudinal trapped modes in the circular vacuum chamber design may cause excessive heating. Adding ferrite tiles on the circular vacuum chamber wall can strongly damp these trapped modes. We will present and discuss the simulation results.
International Nuclear Information System (INIS)
Svoboda, J.; Mori, G.; Prethaler, A.; Fischer, F.D.
2014-01-01
Highlights: • A modeling study for diffusion of hydrogen with traps is presented. • Introduction of a new chemical diffusion coefficient. • Density of traps and average depth of traps can be determined. • Lattice diffusion and sub-surface concentration of atomic hydrogen can be determined. - Abstract: An improved diffusion theory accounting for trapping effects is applied to evaluation of hydrogen permeation experiments performed for pure iron and pearlitic and martensitic steels. The trapping parameters as molar volume and depth of traps are determined by fitting experiments by simulations based on the theory. The concentration-dependent chemical diffusion coefficient of hydrogen is extracted indicating that the trapping effect on diffusion in pure iron and pearlitic steel is negligible. However, it is significant for martensitic steel, for which the chemical diffusion coefficient cannot be considered as concentration-independent as it is established in current standards
DEFF Research Database (Denmark)
Gambalemoke, Mbalitini; Mukinzi, Itoka; Amundala, Drazo
2008-01-01
We investigated the efficiency of four trap types (pitfall, Sherman LFA, Victor snap and Museum Special snap traps) to capture shrews. This experiment was conducted in five inter-riverine forest blocks in the region of Kisangani. The total trapping effort was 6,300, 9,240, 5,280 and 5,460 trap......, our results indicate that pitfall traps are the most efficient for capturing shrews: not only do they have a higher efficiency (yield), but the taxonomic diversity of shrews is also higher when pitfall traps are used....
Light trapping with plasmonic back contacts in thin-film silicon solar cells
Energy Technology Data Exchange (ETDEWEB)
Paetzold, Ulrich Wilhelm
2013-02-08
Trapping light in silicon solar cells is essential as it allows an increase in the absorption of incident sunlight in optically thin silicon absorber layers. This way, the costs of the solar cells can be reduced by lowering the material consumption and decreasing the physical constraints on the material quality. In this work, plasmonic light trapping with Ag back contacts in thin-film silicon solar cells is studied. Solar cell prototypes with plasmonic back contacts are presented along with optical simulations of these devices and general design considerations of plasmonic back contacts. Based on three-dimensional electromagnetic simulations, the conceptual design of plasmonic nanostructures on Ag back contacts in thin-film silicon solar cells is studied in this work. Optimizations of the nanostructures regarding their ability to scatter incident light at low optical losses into large angles in the silicon absorber layers of the thin-film silicon solar cells are presented. Geometrical parameters as well as the embedding dielectric layer stack of the nanostructures on Ag layers are varied. Periodic as well as isolated hemispherical Ag nanostructures of dimensions above 200 nm are found to scatter incident light at high efficiencies and low optical losses. Hence, these nanostructures are of interest for light trapping in solar cells. In contrast, small Ag nanostructures of dimension below 100 nm are found to induce optical losses. At the surface of randomly textured Ag back contacts small Ag nanostructures exist which induce optical losses. In this work, the relevance of these localized plasmon induced optical losses as well as optical losses caused by propagating plasmons are investigated with regard to the reflectance of the textured back contacts. In state-of-the-art solar cells, the plasmon-induced optical losses are shifted out of the relevant wavelength range by incorporating a ZnO:Al interlayer of low refractive index at the back contact. The additional but
Paul's community formation in 1 Thessalonians: The creation of ...
African Journals Online (AJOL)
2015-06-04
Jun 4, 2015 ... Cho, K., Van Eck, E. & Wepener, ... Read online: .... Paul labels as 'the gospel of God' (1 Thes 2:2, 8–9) and 'the ..... Raymond Collins (1984) .... Van Eck, E., 2011, 'Social memory and identity: Luke 19:12b–24 and 27', Biblical.
Revised Mulliken Electronegativities I. Calculation and Conversion to Pauling Units.
Bratsch, Steven G.
1988-01-01
Discusses a revision and extension of the Mulliken electronegativity scale to consider 50 elements. Describes the calculation of valence-state promotion energies and Mulliken atomic electronegativities and the conversion of Mulliken electronegativities to Pauling units. (CW)
Simulators in the training program for nuclear power plants
International Nuclear Information System (INIS)
Grimm, E.
1988-01-01
The principle simulator of the reactor school of the Paul Scherrer Institute is described. A compact simulator at the nuclear power plant Beznau is used for beginners as well as for refresher courses. Full simulator training cannot be taken in Switzerland. The Swiss nuclear power plants take advantage of the services of foreign nuclear power plants or training centers. The role of the instructor is discussed
From transistor to trapped-ion computers for quantum chemistry.
Yung, M-H; Casanova, J; Mezzacapo, A; McClean, J; Lamata, L; Aspuru-Guzik, A; Solano, E
2014-01-07
Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.
The ability to detect populations of boll weevils, Anthonomus grandis (Boheman), with pheromone traps has contributed significantly in progress toward eradication of the boll weevil. However, new information is needed to aid in the interpretation of trap captures, such as identification of habitats...
Photonic crystals for light trapping in solar cells
Energy Technology Data Exchange (ETDEWEB)
Gjessing, Jo
2012-07-25
under oblique incidence angles can to a large degree be predicted by considering the number of escaping diffraction orders which may easily be found from the grating equation. In addition to the well-known structures mentioned above I also introduce novel light trapping structures. I use these structures to investigate what level of light trapping that may be achieved by freely selecting the unit cell geometry. The best light trapping is achieved for structures with low symmetry in their unit cells. The light confinement of one such structure even exceeds the Lambertian light trapping for normal incident light. Lambertian light trapping assumes total randomization of light inside the absorbing material. From geometric optics considerations such a structure will provide the maximum achievable light trapping within a dielectric slab. The Lambertian limit is independent of incidence angle and is therefore valid for isotropic illumination. To experimentally study light trapping from periodic structures, and moreover to compare with our numerical simulations, we had periodic cylinder arrays fabricated i by photolithography. The samples were divided into small blocks of cylinder arrays where lattice geometries and lattice periods varied between the blocks. The measured reflectances from the different blocks are in qualitative agreement with the numerical simulations. A quantitative comparison, on the other hand, is difficult due to the small size of the structured areas. I have also been a part of a team at IFE investigating fabrication methods which may be better suited than photolithography for low-cost fabrication of photonic crystals for solar cells. These methods comprise nano imprint lithography on very thin Si substrates and self-assembled structures using nanospheres. The work focused mainly on control and understanding of the fabrication methods. My contributions to this work were in transfer of the nano imprinted structures from the resist to the substrate and the
Photonic crystals for light trapping in solar cells
International Nuclear Information System (INIS)
Gjessing, Jo
2012-01-01
under oblique incidence angles can to a large degree be predicted by considering the number of escaping diffraction orders which may easily be found from the grating equation. In addition to the well-known structures mentioned above I also introduce novel light trapping structures. I use these structures to investigate what level of light trapping that may be achieved by freely selecting the unit cell geometry. The best light trapping is achieved for structures with low symmetry in their unit cells. The light confinement of one such structure even exceeds the Lambertian light trapping for normal incident light. Lambertian light trapping assumes total randomization of light inside the absorbing material. From geometric optics considerations such a structure will provide the maximum achievable light trapping within a dielectric slab. The Lambertian limit is independent of incidence angle and is therefore valid for isotropic illumination. To experimentally study light trapping from periodic structures, and moreover to compare with our numerical simulations, we had periodic cylinder arrays fabricated i by photolithography. The samples were divided into small blocks of cylinder arrays where lattice geometries and lattice periods varied between the blocks. The measured reflectances from the different blocks are in qualitative agreement with the numerical simulations. A quantitative comparison, on the other hand, is difficult due to the small size of the structured areas. I have also been a part of a team at IFE investigating fabrication methods which may be better suited than photolithography for low-cost fabrication of photonic crystals for solar cells. These methods comprise nano imprint lithography on very thin Si substrates and self-assembled structures using nanospheres. The work focused mainly on control and understanding of the fabrication methods. My contributions to this work were in transfer of the nano imprinted structures from the resist to the substrate and the
The Personal Tragedy in Paul Hindemith's Mathis de Maler
Directory of Open Access Journals (Sweden)
Sharri K Hall
2018-03-01
Full Text Available Paul Hindemith is hardly remembered for his music prior to the 1940s. During the Nazi occupation of Germany in the early 20th century, Paul Hindemith, reviled for his modernistic styles and relation to his Jewish wife, was forced to emigrate out of the Third Reich for his safety. Hindemith was known for his connections to New Objectivity, Gebrachsmusik, and tonality instability placed him in the wrong realm of composition in the Nazi’s minds. As Hitler rose to power in 1933, Hindemith knew he would need a composition to prove his worth amongst the Nazis. As such, Hindemith attempted to change his tides through the composition of the opera/symphony Mathis der Maler. Mathis featured the strong tonality, German nationalism, and Romantic monumentality the Nazis were hoping for to strengthen their regime and the global understanding of German culture. However, Mathis also illustrated Hindemith’s personal pains and struggles with the Reich.
La conversion de Paul, regards croisés Paul’s conversion. Cross perspectives
Directory of Open Access Journals (Sweden)
Elian Cuvillier
2009-09-01
Full Text Available Au plan historique, les traditions relatives à la conversion de Paul, chutant de son cheval sur le chemin de Damas, confrontent l’exégète à trois problèmes importants : y avait-il un cheval, cela se passait-il sur le chemin de Damas et était-ce bien une conversion ? Entendues avec l’humour et la distance critique nécessaires, ces trois questions constituent les trois chapitres de cet article. Le premier « Y avait-il un cheval ? » s’intéresse à l’histoire de la réception de l’épisode de la conversion de Paul, en particulier dans la peinture et la littérature. Le second « Cela se passait-il sur le chemin de Damas ? » est consacrée au récit que l’auteur du livre des Actes propose de la conversion de Paul, récit qui constitue, bien souvent, la porte d’entrée exclusive pour aborder le thème. Le troisième « Etait-ce bien une conversion ? » analyse les témoignages de l’apôtre lui-même à travers deux passages clés de ses épîtres authentiques.Historically speaking, the traditions concerning the conversion of Paul, falling from his horse on the road to Damascus, confront the exegete with three important problems : was there a horse, did it happen on the road to Damacus and was it really a conversion ? These three questions, considered with humor and critical distance, constitute the three sections of this article. The first part « Was there a horse ? » considers the history of the reception of the episode of the conversion of Paul, particularly in art and literature. The second one « Did it happen on the road to Damascus ? » is devoted to the story of the conversion of Paul proposed by the author of the book of Acts, which is very often the exclusive entrance to the discussion of this theme. The third section « Was it really a conversion ? » analyzes the account given by the apostle himself in two key passages of his authentic epistles.
Trapped field recovery of bulk superconductor magnets by static field magnetization
Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.
2011-11-01
Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa2Cu3Oy (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.
Richard, R. L.; El-Alaoui, M.; Ashour-Abdalla, M.; Walker, R. J.
2009-04-01
We have modeled the entry of solar energetic particles (SEPs) into the magnetosphere during the November 24-25, 2001 magnetic storm and the trapping of particles in the inner magnetosphere. The study used the technique of following many test particles, protons with energies greater than about 100 keV, in the electric and magnetic fields from a global magnetohydrodynamic (MHD) simulation of the magnetosphere during this storm. SEP protons formed a quasi-trapped and trapped population near and within geosynchronous orbit. Preliminary data comparisons show that the simulation does a reasonably good job of predicting the differential flux measured by geosynchronous spacecraft. Particle trapping took place mainly as a result of particles becoming non-adiabatic and crossing onto closed field lines. Particle flux in the inner magnetosphere increased dramatically as an interplanetary shock impacted and compressed the magnetosphere near 0600 UT, but long term trapping (hours) did not become widespread until about an hour later, during a further compression of the magnetosphere. Trapped and quasi-trapped particles were lost during the simulation by motion through the magnetopause and by precipitation, primarily the former. This caused the particle population near and within geosynchronous orbit to gradually decrease later on during the latter part of the interval.
Magnetic traps with a sperical separatrix: Tornado traps
International Nuclear Information System (INIS)
Peregood, B.P.; Lehnert, B.
1979-11-01
A review is given on the features of magnetic traps with a spherical separatrix, with special emphesis on Tornado spiral coil configurations. The confinement and heating of static plasmas in Tornado traps is treated, including the topology of the magnetic field structure, the magneto-mechanical properties of the magnetic coil system, as well as the particle orbits and plasma behaviour in these traps. In additio, the mode of rotating plasma operation by crossed electric and magnetic fields is being described. The results of experiments on static and rotating plasmas are summarized, and conclusions are drawn about future possibilities of Tornado traps for the creation and containment of hot plasmas. (author)
Magnetic traps with a spherical separatrix: Tornado traps
International Nuclear Information System (INIS)
Peregood, B.P.; Lehnert, B.
1981-01-01
A review is given on the features of magnetic traps with a spherical separatrix, with special emphasis on Tornado spiral coil configurations. The confinement and heating of static plasms in Tornado traps is treated, including the topology of the magnetic field structure, the magneto-mechanical properties of the magnetic coil system, as well as the particle orbits and plasma behaviour in these traps. In addition, the mode of rotating plasma operation by crossed electric and magnetic fields is described. The results of experiments on static and rotating plasmas are summarized, and conclusions are drawn about future possibilities of Tornado traps in the creation and containment of hot plasmas. (orig.)
Rhee, Jihyun; Choi, Sungju; Kang, Hara; Kim, Jae-Young; Ko, Daehyun; Ahn, Geumho; Jung, Haesun; Choi, Sung-Jin; Myong Kim, Dong; Kim, Dae Hwan
2018-02-01
Experimental extraction of the electron trap parameters which are associated with charge trapping into gate insulators under the positive bias temperature stress (PBTS) is proposed and demonstrated for the first time in amorphous indium-gallium-zinc-oxide thin-film transistors. This was done by combining the PBTS/recovery time-evolution of the experimentally decomposed threshold voltage shift (ΔVT) and the technology computer-aided design (TCAD)-based charge trapping simulation. The extracted parameters were the trap density (NOT) = 2.6 × 1018 cm-3, the trap energy level (ΔET) = 0.6 eV, and the capture cross section (σ0) = 3 × 10-19 cm2. Furthermore, based on the established TCAD framework, the relationship between the electron trap parameters and the activation energy (Ea) is comprehensively investigated. It is found that Ea increases with an increase in σ0, whereas Ea is independent of NOT. In addition, as ΔET increases, Ea decreases in the electron trapping-dominant regime (low ΔET) and increases again in the Poole-Frenkel (PF) emission/hopping-dominant regime (high ΔET). Moreover, our results suggest that the cross-over ΔET point originates from the complicated temperature-dependent competition between the capture rate and the emission rate. The PBTS bias dependence of the relationship between Ea and ΔET suggests that the electric field dependence of the PF emission-based electron hopping is stronger than that of the thermionic field emission-based electron trapping.
2011-01-11
... of Attainment by the Applicable Attainment Date for the Hayden, Nogales, Paul Spur/Douglas PM 10... making final determinations that the Hayden, Nogales, and Paul Spur/Douglas nonattainment areas in... the Clean Air Act, that three Arizona ``moderate'' PM 10 nonattainment areas (Hayden, Nogales, and...
Spécificité pastorale de la personnalité de Jean-Paul II selon Jean-Marie Lustiger
Directory of Open Access Journals (Sweden)
Ryszard Biernat
2011-04-01
Full Text Available Jean-Marie Lustiger admired John Paul II and he was devoted to him. They both had similar origin. The Cardinal of Paris often accompanied the pope in his pastoral visits. He perceived John Paul II as the man of Providence. He was convinced that God had prepared him to this role. Jean-Marie Lustiger emphasized the attitudes of John Paul II that attracted the attention and admiration of observers. For instance: pray, holiness, attentive pastor and good relation with young people. Jean-Marie Lustiger as an attentive observer also focused his attention on the pastoral methods of John Paul II. In his utterances he often perceived the following methods: each person was important, defense of person’s dignity, the ability to speak with each man, modern language, importance of the pastoral visits and sui generis spiritual pedagogic. Jean-Marie Lustiger noticed radical change of perspective in preaching and in pastoral action of John Paul II. According to him the pope perceived the challenges of the modern times, evaluated needs of the humanity and gave the appropriate answers. For these he did not choose politics, sociology or even anthropology as a re fl ection but addressed to the hurt human who was redeem by Jesus Christ.
Mass-selective isolation of ions stored in a quadrupole ion trap. A simulation study
March, Raymond E.; Londry, Frank A.; Alfred, Roland L.; Franklin, Anthony M.; Todd, John F. J.
1992-01-01
Trajectories of single ions stored in the quadrupole ion trap have been calculated using a simulation program described as the specific program for quadrupolar resonance (SPQR). Previously, the program has been used for the investigation of quadrupolar resonance excitation of ions with a static working point (or co-ordinates) in the stability diagram. The program has been modified to accommodate continuous d.c. and/or r.f. voltage ramps so as to permit calculation of ion trajectories while the working point is being changed. The modified program has been applied to the calculation of ion trajectories during ion isolation, or mass-selective storage, in the ion trap. The quadrupolar resonance excitation aspect of SPQR was not used in this study. Trajectories are displayed as temporal variations of ion kinetic energy, and axial and radial excursions from the centre of the ion trap. The working points of three ion species (m/z 144, 146 and 148), located initially on the qz, axis with qz [approximate] 0.12, were moved to the vicinity of the upper apex by a combination of r.f. and d.c. voltages applied in succession. Stable trajectories were maintained only for the ion species of m/z 146 for which the working point lay within this apex; the other ion species were ejected either radially or axially. The d.c. voltage was then reduced to zero so as to restore the working point of the isolated ion species to the qz axis. The amplitude of the r.f voltage was reduced to its initial value so as to retrieve the initial working point for m/z 146. The process extended over a real time of 2.9 ms, and was collision-free. The trajectory of the isolated ion was stable during this process; the ion species with m/z value lower than that of the target ion, that is, m/z 144, was ejected axially at the [beta]z = 1 boundary, while that with higher m/z value, that is, m/z 148, was ejected radially at the [beta]r = 0 boundary, as expected. The moderating effects of buffer gas were not taken
Evaluation of double-decker traps for emerald ash borer (Coleoptera: Buprestidae).
Poland, Therese M; McCullough, Deborah G; Anulewicz, Andrea C
2011-04-01
Improved detection tools are needed for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive forest insect from Asia that has killed millions of ash (Fraxinus spp.) trees in North America since its discovery in Michigan in 2002. We evaluated attraction of adult A. planipennis to artificial traps incorporating visual (e.g., height, color, silhouette) and olfactory cues (e.g., host volatiles) at field sites in Michigan. We developed a double-decker trap consisting of a 3-m-tall polyvinyl pipe with two purple prisms attached near the top. In 2006, we compared A. planipennis attraction to double-decker traps baited with various combinations of manuka oil (containing sesquiterpenes present in ash bark), a blend of four ash leaf volatiles (leaf blend), and a rough texture to simulate bark. Significantly more A. planipennis were captured per trap when traps without the rough texture were baited with the leaf blend and manuka oil lures than on traps with texture and manuka oil but no leaf blend. In 2007, we also tested single prism traps set 1.5 m above ground and tower traps, similar to double-decker traps but 6 m tall. Double-decker traps baited with the leaf blend and manuka oil, with or without the addition of ash leaf and bark extracts, captured significantly more A. planipennis than similarly baited single prism traps, tower traps, or unbaited double-decker traps. A baited double-decker trap captured A. planipennis at a field site that was not previously known to be infested, representing the first detection event using artificial traps and lures. In 2008, we compared purple or green double-decker traps, single prisms suspended 3-5 m above ground in the ash canopy (canopy traps), and large flat purple traps (billboard traps). Significantly more A. planipennis were captured in purple versus green traps, baited traps versus unbaited traps, and double-decker versus canopy traps, whereas billboard traps were intermediate. At sites
50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.
2010-10-01
... vessels fishing with lobster traps. 697.19 Section 697.19 Wildlife and Fisheries FISHERY CONSERVATION AND... requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish... management area designation certificate or valid limited access American lobster permit specifying one or...
Acoustic rainbow trapping by coiling up space
Ni, Xu
2014-11-13
We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.
Acoustic rainbow trapping by coiling up space
Ni, Xu; Wu, Ying; Chen, Ze-Guo; Zheng, Li-Yang; Xu, Ye-Long; Nayar, Priyanka; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng
2014-01-01
We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.
EnviroAtlas - Minneapolis/St. Paul, MN - Ecosystem Services by Block Group
U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,772 block groups in Minneapolis/St. Paul, Minnesota. Carbon attributes, temperature...
International Nuclear Information System (INIS)
Villard, L.; Allfrey, S.J.; Bottino, A.
2003-01-01
The aim of this paper is to report on recent advances made on global gyrokinetic simulations of Ion Temperature Gradient modes (ITG) and other microinstabilities. The nonlinear development and saturation of ITG modes and the role of E x B zonal flows are studied with a global nonlinear δ f formulation that retains parallel nonlinearity and thus allows for a check of the energy conservation property as a means to verify the quality of the numerical simulation. Due to an optimised loading technique the conservation property is satisfied with an unprecedented quality well into the nonlinear stage. The zonal component of the perturbation establishes a quasi-steady state with regions of ITG suppression, strongly reduced radial energy flux and steepened effective temperature profile alternating with regions of higher ITG mode amplitudes, larger radial energy flux and flattened effective temperature profile. A semi-Lagrangian approach free of statistical noise is proposed as an alternative to the nonlinear δf formulation. An ASDEX-Upgrade experiment with an Internal Transport Barrier (ITB) is analysed with a global gyrokinetic code that includes trapped electron dynamics. The weakly destabilizing effect of trapped electron dynamics on ITG modes in an axisymmetric bumpy configuration modelling W7-X is shown in global linear simulations that retain the full electron dynamics. Finite β effects on microinstabilities are investigated with a linear global spectral electromagnetic gyrokinetic formulation. The radial global structure of electromagnetic modes shows a resonant behaviour with rational q values. (author)
PSI Paul Scherrer Institute; PSI Institut Paul Scherrer
Energy Technology Data Exchange (ETDEWEB)
Lefrancois, M.; Pladys, D
2008-05-15
From research activities focused on civil and military uses of nuclear energy and developed after the second world war, the Paul Scherrer Institute (PSI) has been able to diversify its activities following 2 axis. First, the Gantry proton-therapy that is characterized by a compact equipment and an accurate 3-dimensional treatment of tumors (more than 260 patients have been treated by Gantry from 1996 to 2005). Secondly, new technologies in the fields of energy and transport. Nevertheless, PSI has been able to keep a high of valuation of its staff in nuclear engineering and materials that are the core of its activities. The main equipment of PSI are: -) SLS (Swiss Light Source): a synchrotron radiation source that is both a microscope and an X-ray source; -) SINQ: a neutron source based on spallation reactions; -)S{mu}S: a muon source; and -) the Philips accelerator that is used in radiochemistry and the production of isotopes used for the treatment of eye tumors. PSI has established a large cooperation with French research laboratories on issues like: nuclear reactor safety, synchrotron radiation, the transmutation of nuclear wastes, the design of a source of ultra-cold neutrons, or the development of a hydrogen-fueled light vehicle. The total budget of PSI for 2007 reached 174.2 million euros. (A.C.)
ELECTRON TRAPPING IN WIGGLER AND QUADRUPOLE MAGNETS OF CESRTA
International Nuclear Information System (INIS)
Wang, Lanfa
2010-01-01
The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in the wiggler and quadrupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with long lifetime in a quadrupole magnet due to the mirror field trapping mechanism and photoelectrons produced in the wiggler zero field zone have long lifetime due to their complicated trajectory.
International Nuclear Information System (INIS)
Klimas, A.J.
1990-01-01
Trapping saturation of the bump-on-tail instability is discussed using electron plasma Vlasov simulation results. The role of electrostatic harmonic excitation is considered in detail and shown to play a decisive role in the saturation of the instability. An extensive discussion of the simulation results is given to show that the results are not significantly limited by the finite number of Fourier modes used nor by the discrete distribution of those modes in wave number. It is argued that in the leading edge of Earth's electron foreshock a narrow wave number band of unstable field modes leads to trapping saturation of the bump-on-tail instability while simultaneously exciting electrostatic plasma waves at harmonics of the plasma frequency in simialr narrow bands of shorter wavelengths. The argument is based (1) on the observations of Lacombe et al. (1985), who found intense plasma waves at the leading edge of the foreshock with a spectral distribution sufficiently narrow to trap particles in resonance with the waves, and (2) on numerical simulations of the foreshock electron plasma which indicate that trapping saturation of the bump-on-tail instability leads to phase space vortex formation with consequent excitation of electrostatic harmonics. Thus it is suggested that observations of electrostatic harmonics in the leading edge of the foreshock would strongly implicate trapping as the saturation mechanism for the bump-on-tail instability in that region
Dependence of the shape of graphene nanobubbles on trapped substance
Ghorbanfekr-Kalashami, H.; Vasu, K. S.; Nair, R. R.; Peeters, François M.; Neek-Amal, M.
2017-06-01
Van der Waals (vdW) interaction between two-dimensional crystals (2D) can trap substances in high pressurized (of order 1 GPa) on nanobubbles. Increasing the adhesion between the 2D crystals further enhances the pressure and can lead to a phase transition of the trapped material. We found that the shape of the nanobubble can depend critically on the properties of the trapped substance. In the absence of any residual strain in the top 2D crystal, flat nanobubbles can be formed by trapped long hydrocarbons (that is, hexadecane). For large nanobubbles with radius 130 nm, our atomic force microscopy measurements show nanobubbles filled with hydrocarbons (water) have a cylindrical symmetry (asymmetric) shape which is in good agreement with our molecular dynamics simulations. This study provides insights into the effects of the specific material and the vdW pressure on the microscopic details of graphene bubbles.
Some neutronic studies on flux-trap type moderator
International Nuclear Information System (INIS)
Kiyanagi, Y.; Watanabe, N.
1991-01-01
The neutronic performance of a flux-trap type moderator was studied by computer simulation in connection with the KENS-II target-moderator system. It was confirmed that this system can provide 1.3-1.4 times higher neutron intensity than a traditional wing-geometry moderator system. (author)
Sideband-cooling of trapped ytterbium-ions in the microwave regime
International Nuclear Information System (INIS)
Scharfenberger, Benedikt J.
2012-01-01
Trapped ions in a Paul trap are at present one of the most promising candidates for Quantum Information Processing (QIP). The technique that is used for this purpose in this experiment was introduced in 2001 by F. Mintert and Ch. Wunderlich. The core of this method is the use of atomic transitions in the radio- or microwave region, while a magnetic field gradient along the trap axis (where the ion chain is situated) lifts the degeneracy of the transition frequencies, such that the ions can be distinguished in frequency space; it also serves for the coupling of internal and external degrees of freedom of the ion chain. This method is called MAGIC (MAgnetic Gradient Induced Coupling). The performance of the measurements required that the apparatus of the experiment, which consists of laser sources, lambdameter, vacuum- and microwave system as well as imaging- and detection-units, had to be assembled and tested, which was an important prerequisite for the successful performance of the here described experiments. For the experiments it is advantageous to prepare the ions in an energetic state close to the motional ground state, which contributes to a reduction of the dephasing of the system while manipulating it with microwaves. By using the sideband-cooling technique to the sub-Doppler regime it is taken advantage of the fact, that ions in a linear trap are in good approximation situated in a harmonic oscillator potential and can therefore only populate discrete vibrational energy levels, whose frequency difference is given by the axial trap frequency ω z . If the system is excited by a microwave, which frequency is detuned from resonance to lower energies by a vibrational quantum, the ion looses one such phonon within each cooling-cycle. When this cycle is driven several times, the average phonon number and thus the temperature of the ion can be reduced efficiently and the ion can be initialized in a state close to the motional ground state. As sideband
The Multipole Plasma Trap-PIC Modeling Results
Hicks, Nathaniel; Bowman, Amanda; Godden, Katarina
2017-10-01
A radio-frequency (RF) multipole structure is studied via particle-in-cell computer modeling, to assess the response of quasi-neutral plasma to the imposed RF fields. Several regimes, such as pair plasma, antimatter plasma, and conventional (ion-electron) plasma are considered. In the case of equal charge-to-mass ratio of plasma species, the effects of the multipole field are symmetric between positive and negative particles. In the case of a charge-to-mass disparity, the multipole RF parameters (frequency, voltage, structure size) may be chosen such that the light species (e.g. electrons) is strongly confined, while the heavy species (e.g. positive ions) does not respond to the RF field. In this case, the trapped negative space charge creates a potential well that then traps the positive species. 2D and 3D particle-in-cell simulations of this concept are presented, to assess plasma response and trapping dependences on multipole order, consequences of the formation of an RF plasma sheath, and the effects of an axial magnetic field. The scalings of trapped plasma parameters are explored in each of the mentioned regimes, to guide the design of prospective experiments investigating each. Supported by U.S. NSF/DOE Partnership in Basic Plasma Science and Engineering Grant PHY-1619615.
Axicon-based annular laser trap for studies on sperm activity
Shao, Bing; Vinson, Jaclyn M.; Botvinick, Elliot L.; Esener, Sadik C.; Berns, Michael W.
2005-08-01
As a powerful and noninvasive tool, laser trapping has been widely applied for the confinement and physiological study of biological cells and organelles. Researchers have used the single spot laser trap to hold individual sperm and quantitatively evaluated the motile force generated by a sperm. Early studies revealed the relationship between sperm motility and swimming behavior and helped the investigations in medical aspects of sperm activity. As sperm chemotaxis draws more and more interest in fertilization research, the studies on sperm-egg communication may help to explain male or female infertility and provide exciting new approaches to contraception. However, single spot laser trapping can only be used to investigate an individual target, which has limits in efficiency and throughput. To study the chemotactic response of sperm to eggs and to characterize sperm motility, an annular laser trap with a diameter of several hundred microns is designed, simulated with ray tracing tool, and implemented. An axicon transforms the wavefront such that the laser beam is incident on the microscope objective from all directions while filling the back aperture completely for high efficiency trapping. A trapping experiment with microspheres is carried out to evaluate the system performance. The power requirement for annular sperm trapping is determined experimentally and compared with theoretical calculations. With a chemo-attractant located in the center and sperm approaching from all directions, the annular laser trapping could serve as a speed bump for sperm so that motility characterization and fertility sorting can be performed efficiently.
International Nuclear Information System (INIS)
Yin, L.; Albright, B. J.; Bowers, K. J.; Daughton, W.; Rose, H. A.
2008-01-01
Backward stimulated Raman and Brillouin scattering (SRS and SBS) of laser are examined in the kinetic regime using particle-in-cell simulations. The SRS reflectivity measured as a function of the laser intensity in a single hot spot from two-dimensional (2D) simulations shows a sharp onset at a threshold laser intensity and a saturated level at higher intensities, as obtained previously in Trident experiments [D. S. Montgomery et al., Phys. Plasmas 9, 2311 (2002)]. In these simulations, wavefront bowing of electron plasma waves (ion acoustic waves) due to the trapped particle nonlinear frequency shift, which increases with laser intensity, is observed in the SRS (SBS) regime for the first time. Self-focusing from trapped particle modulational instability (TPMI) [H. A. Rose, Phys. Plasmas 12, 12318 (2005)] is shown to occur in both two- and three-dimensional SRS simulations. The key physics underlying nonlinear saturation of SRS is identified as a combination of wavefront bowing, TPMI, and self-focusing of electron plasma waves. The wavefront bowing marks the beginning of SRS saturation and self-focusing alone is sufficient to terminate the SRS reflectivity, both effects resulting from cancellation of the source term for SRS and from greatly increased dissipation rate of the electron plasm waves. Ion acoustic wave bowing also contributes to the SBS saturation. Velocity diffusion by transverse modes and rapid loss of hot electrons in regions of small transverse extent formed from self-focusing lead to dissipation of the wave energy and an increase in the Landau damping rate in spite of strong electron trapping that reduces Landau damping initially. The ranges of wavelength and growth rate associated with transverse breakup of the electron-plasma wave are also examined in 2D speckle simulations as well as in 2D periodic systems from Bernstein-Greene-Kruskal equilibrium and are compared with theory predictions
2010-11-02
... of Attainment by the Applicable Attainment Date for the Hayden, Nogales, Paul Spur/Douglas PM 10...: EPA has determined that the Hayden, Nogales, and Paul Spur/ Douglas nonattainment areas in Arizona... of a review of more recent ambient monitoring data, EPA has determined that the Hayden, Nogales, and...
International Nuclear Information System (INIS)
Niedermayr, M.
2015-01-01
Microfabricated surface traps are a promising architecture to realize a scalable quantum computer based on trapped ions. In principle, hundreds or thousands of surface traps can be located on a single substrate in order to provide large arrays of interacting ions. To this end, trap designs and fabrication methods are required that provide scalable, stable and reproducible ion traps. This work presents a novel surface-trap design developed for cryogenic applications. Intrinsic silicon is used as the substrate material of the traps. The well-developed microfabrication and structuring methods of silicon are utilized to create simple and reproducible traps. The traps were tested and characterized in a cryogenic setup. Ions could be trapped and their life time and motional heating were investigated. Long ion lifetimes of several hours were observed and the measured heating rates were reproducibly low at around 1 phonon per second at a trap frequency of 1 MHz. (author) [de
Artificial covering on trap nests improves the colonization of trap-nesting wasps
Taki, Hisatomo; Kevan, Peter G.; Viana, Blandina Felipe; Silva, Fabiana O.; Buck, Matthias
2008-01-01
Acesso restrito: Texto completo. p. 225-229 To evaluate the role that a trap-nest cover might have on sampling methodologies, the abundance of each species of trap-nesting Hymenoptera and the parasitism rate in a Canadian forest were compared between artificially covered and uncovered traps. Of trap tubes exposed at eight forest sites in six trap-nest boxes, 531 trap tubes were occupied and 1216 individuals of 12 wasp species of four predatory families, Vespidae (Eumeninae), Crabronidae...
Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap
Amole, C; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Hydomako, R; Kurchaninov, L; Jonsell, S; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S
2012-01-01
Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antipr...
The research contributions of Dr. Paul Van Deusen
Thomas B. Lynch; Francis A. Roesch; John Paul McTague; Jeffrey H. Gove; Gregory A. Reams; Aaron R. Weiskittel
2015-01-01
Dr. Paul Van Deusenâs recent passing concluded a rich 30+-year research career dedicated to development and implementation of quantitative methods for forestry and natural resources. Since the early part of his career as a biometrician with the USDA Forest Service Southern Research Station in the 1980s-1990s and continuing with his later employment at NCASI, Dr. Van...
The decapod and stomatopod Crustacea of St Paul's Rocks
Holthuis, L.B.
1980-01-01
INTRODUCTION Saint Paul's Rocks (Penedos de São Pedro e São Paulo) are a small group of rocky islets on the mid-Atlantic ridge near the equator, occupying an area of roughly 250 by 425 m. There is no vegetation and, apart from birds and invertebrates, the islands are uninhabited. The Cambridge
Mass measurements on radioactive isotopes using the ISOLTRAP spectrometer
Dilling, J; Kluge, H J; Kohl, A; Lamour, E; Marx, G; Schwarz, S C; Bollen, G; Kellerbauer, A G; Moore, R B; Henry, S
2000-01-01
ISOLTRAP is a Penning trap mass spectrometer installed at the on line isotope separator ISOLDE at CERN. Direct measurements of the masses of short lived radio isotopes are performed using the existing triple trap system. This consists of three electromagnetic traps in tandem: a Paul trap to accumulate and bunch the 60 keV dc beam, a Penning trap for cooling and isobar separation, and a precision Penning trap for the determination of the masses by cyclotron resonance. Measurements of masses of unknown mercury isotopes and in the vicinity of doubly magic /sup 208/Pb are presented, all with an accuracy of delta m/m approximately=1*10/sup -7/. Developments to replace the Paul trap by a radiofrequency quadrupole ion guide system to increase the collection efficiency are presently under way and the status is presented. (10 refs).
John Paul II in the face of the reality of Auschwitz
Directory of Open Access Journals (Sweden)
Stanisław Wronka
2014-06-01
Full Text Available In the context of the canonization of John Paul II, the author reflects on his experience of the concentration camp at Auschwitz. It is a difficult experience, therefore it can more reveal the Pope as a man and a pastor, his way of thinking and perceiving reality. Through canonization this way is indicated to us as a pattern. John Paul came often to Auschwitz, where he saw the place of denial of God and man, but also a place of victory of man over contempt, hatred and death through faith in God, which generates love for Him and for man. The symbol of such a victory is St. Maximilian Maria Kolbe, martyr of love that as Christ gave his life for the fellow prisoner Francis Gajowniczek. In this heroic deed – in the opinion of the Pope – Christ himself was present, so the camp at Auschwitz is not only hell on earth, but also the Golgotha of our times, the cemetery of the martyrs, the sanctuary of the patron of difficult century. Pope John Paul II arrived there to pray and make a reflection on the contemporary man’s condition, who in Christ the Redeemer can still conquer evil with good and to build the peace based on respect for the rights of person and nations.
Valuable books from the library of Paul Gore (Identification and/or inventory of sources
Directory of Open Access Journals (Sweden)
Maria Danilov
2013-12-01
Full Text Available Paul Gore (1875-1927 - an outstanding figure of the socio-political, scientific and cultural life of Bessarabia at the beginning of 20th century, was also known among his contemporaries as a keen collector of old and rare books. Undoubtedly, the most valuable part of the library of Paul Gore consisted of books on the history of Bessarabia. Documents from the National Archives of the Republic of Moldova in Chişinău confirm that he inherited a large part of books from his father Gheorghe Gore (1839-1909. A study of the Paul Gore Fund at the National Archives of Romania in Bucharest gave us a lot of documentary evidence of the destiny of this Bessarabian noble library, which later became a property of the King Ferdinand Fund. However, the fate of its most valuable part - books on the history of Bessarabia, consisted of 651 units of the total number of 6456 volumes - is still unknown.
Fast modeling of flux trapping cascaded explosively driven magnetic flux compression generators.
Wang, Yuwei; Zhang, Jiande; Chen, Dongqun; Cao, Shengguang; Li, Da; Liu, Chebo
2013-01-01
To predict the performance of flux trapping cascaded flux compression generators, a calculation model based on an equivalent circuit is investigated. The system circuit is analyzed according to its operation characteristics in different steps. Flux conservation coefficients are added to the driving terms of circuit differential equations to account for intrinsic flux losses. To calculate the currents in the circuit by solving the circuit equations, a simple zero-dimensional model is used to calculate the time-varying inductance and dc resistance of the generator. Then a fast computer code is programmed based on this calculation model. As an example, a two-staged flux trapping generator is simulated by using this computer code. Good agreements are achieved by comparing the simulation results with the measurements. Furthermore, it is obvious that this fast calculation model can be easily applied to predict performances of other flux trapping cascaded flux compression generators with complex structures such as conical stator or conical armature sections and so on for design purpose.
Performing Protest in Cross-Cultural Spaces: Paul Robeson and Othello
Directory of Open Access Journals (Sweden)
Sawyer Robert
2017-09-01
Full Text Available When the famous African-American actor and singer Paul Robeson played the lead in Shakespeare’s Othello in London in 1930, tickets were in high demand during the production’s first week. The critical response, however, was less positive, although the reviews unanimously praised his bass-baritone delivery. When Robeson again played Othello on Broadway thirteen years later, critics praised not only his voice but also his acting, the drama running for 296 performances. My argument concerning Robeson uses elements first noted by Henri Lefebvre in his seminal work, The Production of Space, while I also draw on Paul Connerton’s work on commemorative practices. Using spatial and memorial theories as a backdrop for examining his two portrayals, I suggest that Robeson’s nascent geopolitical awareness following the 1930 production, combined with his already celebrated musical voice, allowed him to perform the role more dramatically in 1943.
2010-11-29
... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [R09-OAR-2010-0718; FRL-9233-1] Determinations of Attainment by the Applicable Attainment Date for the Hayden, Nogales, Paul Spur/Douglas PM10 Nonattainment... November 2, 2010 (75 FR 67220), direct final rule determining that the Hayden, Nogales, and Paul Spur...
Corvol, Pierre
2013-01-01
Cher Collègue, Cher Paul Colonna, Il y a moins de vingt ans est apparue dans le monde une nouvelle chimie, la chimie verte. Cette chimie est une alternative à l’utilisation du carbone fossile et d’autres types d’énergie non renouvelables (gaz, charbon). La chimie traditionnelle à base de pétrole est certes performante, créative, compétitive, et répond bien à nos besoins, mais elle est aussi polluante et épuise les ressources de carbone fossile. La chimie verte se développe à côté de la chimie...
Magnetic monopole search with the MoEDAL test trapping detector
Directory of Open Access Journals (Sweden)
Katre Akshay
2016-01-01
Full Text Available IMoEDAL is designed to search for monopoles produced in high-energy Large Hadron Collider (LHC collisions, based on two complementary techniques: nucleartrack detectors for high-ionisation signatures and other highly ionising avatars of new physics, and trapping volumes for direct magnetic charge measurements with a superconducting magnetometer. The MoEDAL test trapping detector array deployed in 2012, consisting of over 600 aluminium samples, was analysed and found to be consistent with zero trapped magnetic charge. Stopping acceptances are obtained from a simulation of monopole propagation in matter for a range of charges and masses, allowing to set modelindependent and model-dependent limits on monopole production cross sections. Multiples of the fundamental Dirac magnetic charge are probed for the first time at the LHC.
Magnetic monopole search with the MoEDAL test trapping detector
Katre, Akshay
2016-11-01
IMoEDAL is designed to search for monopoles produced in high-energy Large Hadron Collider (LHC) collisions, based on two complementary techniques: nucleartrack detectors for high-ionisation signatures and other highly ionising avatars of new physics, and trapping volumes for direct magnetic charge measurements with a superconducting magnetometer. The MoEDAL test trapping detector array deployed in 2012, consisting of over 600 aluminium samples, was analysed and found to be consistent with zero trapped magnetic charge. Stopping acceptances are obtained from a simulation of monopole propagation in matter for a range of charges and masses, allowing to set modelindependent and model-dependent limits on monopole production cross sections. Multiples of the fundamental Dirac magnetic charge are probed for the first time at the LHC.
Trapping mechanisms in scattering of beams at grazing incidence from crystals
International Nuclear Information System (INIS)
Smith, R.; O'Connor, D.J.; Felsobuki, E.I. von-Nagy
1993-01-01
The trajectories of grazing incidence, 1 keV beams of Si incident on Cu{111} are investigated by means of molecular dynamics (MD) simulations and the conditions under which atoms in the beam can be trapped in the surface binding potential are investigated. The binding potentials for the Cu-Si dimers are calculated using ab initio methods for the neutral, anion and cation. These calculations estimate the binding potential and equilibrium separation for the potential used for the MD calculations. It is found that at 4 o incidence to the Cu{111} face, no trapping occurs for a perfect crystal surface undergoing no thermal vibrations. Trapping can occur for the Si neutral if thermal vibrations are included in the model. Trapping is predicted to occur near steps on the Cu{111} face but these are fairly rare events for the Si - particles. (Author)
Atomistic modeling trap-assisted tunneling in hole tunnel field effect transistors
Long, Pengyu; Huang, Jun Z.; Povolotskyi, Michael; Sarangapani, Prasad; Valencia-Zapata, Gustavo A.; Kubis, Tillmann; Rodwell, Mark J. W.; Klimeck, Gerhard
2018-05-01
Tunnel Field Effect Transistors (FETs) have the potential to achieve steep Subthreshold Swing (S.S.) below 60 mV/dec, but their S.S. could be limited by trap-assisted tunneling (TAT) due to interface traps. In this paper, the effect of trap energy and location on OFF-current (IOFF) of tunnel FETs is evaluated systematically using an atomistic trap level representation in a full quantum transport simulation. Trap energy levels close to band edges cause the highest leakage. Wave function penetration into the surrounding oxide increases the TAT current. To estimate the effects of multiple traps, we assume that the traps themselves do not interact with each other and as a whole do not modify the electrostatic potential dramatically. Within that model limitation, this numerical metrology study points to the critical importance of TAT in the IOFF in tunnel FETs. The model shows that for Dit higher than 1012/(cm2 eV) IO F F is critically increased with a degraded IO N/IO F F ratio of the tunnel FET. In order to have an IO N/IO F F ratio higher than 104, the acceptable Dit near Ev should be controlled to no larger than 1012/(cm2 eV) .
Results from a Test Fixture for button BPM Trapped Mode Measurements
Energy Technology Data Exchange (ETDEWEB)
Cameron,P.; Bacha, B.; Blednykh, A.; Pinayev, I.; Singh, O.
2009-05-04
A variety of measures have been suggested to mitigate the problem of button BPM trapped mode heating. A test fixture, using a combination of commercial-off-the-shelf and custom machined components, was assembled to validate the simulations. We present details of the fixture design, measurement results, and a comparison of the results with the simulations. A brief history of the trapped mode button heating problem and a set of design rules for BPM button optimization are presented elsewhere in these proceedings. Here we present measurements on a test fixture that was assembled to confirm, if possible, a subset of those rules: (1) Minimize the trapped mode impedance and the resulting power deposited in this mode by the beam. (2) Maximize the power re-radiated back into the beampipe. (3) Maximize electrical conductivity of the outer circumference of the button and minimize conductivity of the inner circumference of the shell, to shift power deposition from the button to the shell. The problem is then how to extract useful and relevant information from S-parameter measurements of the test fixture.
Tightly confined atoms in optical dipole traps
International Nuclear Information System (INIS)
Schulz, M.
2002-12-01
trap depth. In a crossed beam geometry with red-detuned laser light, efficient transfer of atoms between the beams is observed. Optimum transfer occurs when the two beams cross at a radial offset, which can be qualitatively understood when the particle energy and geometrical properties of the two-beam trapping potential are considered. Numerical simulations reproduce the general features of the measured transfer efficiency vs. radial beam offset. Atoms have been radially confined in a blue-detuned hollow beam. This configuration is currently extended to a three-dimensionally confining blue-detuned dipole trap. For advanced laser cooling, state manipulation and spectroscopy, a double-diode laser system has been set up which is phase-locked with a difference frequency near 6.834 GHz to drive Raman transitions between the hyperfine-split ground states of Rb-87 atoms. Dark resonances with linewidths below 100-Hz have been observed in a buffer gas loaded rubidium vapour cell. (author)
20 old and rare books from the library of Paul Gore
Directory of Open Access Journals (Sweden)
Liviu Papuc
2014-12-01
Full Text Available As is well known, most of the large library of Paul Gore, nearly 5,000 volumes, as evidenced by preserved inventory list, is currently kept in the “M. Eminescu” Central University Library in Iaşi. Based on dozens of specimens found in the storages and on the notes made by Paul Gore in the inventory-catalog, the paper presents their bibliographic description. It is made in the continuation of a communication that is to be printed in the Magazine of the Museum of the “Al.I. Cuza” University of Iaşi and in order to complete a full catalog of the library of the great scientist, the work on which was begun with great success by other researchers in the field.
STUDI KOMPARASI SAMINISME DENGAN JEAN PAUL SARTRE TENTANG KEBEBASAN (Tinjauan Filsafat Sosial
Directory of Open Access Journals (Sweden)
Restu Trisnova
2016-09-01
Full Text Available The comparative study between Saminism concept and Jean Paul Sartre thought of freedom are: 1 Human freedom, according to Sartre, is an absolute freedom. No other rules which are able to determine human either God or other people; 2 The Saminism concept of freedom is an individual freedom. It means every individual as a subject is able to decide their own choice. Every individual as a subject is independent without any outside order; 3 Saminism freedom conveys individual responsibility. It means every person’s freedom has individual responsibility. Every doer subject can decide everything based on their interest. Therefore, the freedom and responsibility in Saminism actualizes the Jean Paul Sartre thought of freedom.
Quantum-enhanced deliberation of learning agents using trapped ions
Dunjko, V.; Friis, N.; Briegel, H. J.
2015-02-01
A scheme that successfully employs quantum mechanics in the design of autonomous learning agents has recently been reported in the context of the projective simulation (PS) model for artificial intelligence. In that approach, the key feature of a PS agent, a specific type of memory which is explored via random walks, was shown to be amenable to quantization, allowing for a speed-up. In this work we propose an implementation of such classical and quantum agents in systems of trapped ions. We employ a generic construction by which the classical agents are ‘upgraded’ to their quantum counterparts by a nested process of adding coherent control, and we outline how this construction can be realized in ion traps. Our results provide a flexible modular architecture for the design of PS agents. Furthermore, we present numerical simulations of simple PS agents which analyze the robustness of our proposal under certain noise models.
Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces
International Nuclear Information System (INIS)
David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth
2015-01-01
We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape
Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces
Energy Technology Data Exchange (ETDEWEB)
David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth, E-mail: rsignorell@ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland)
2015-04-21
We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.
David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth
2015-04-21
We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.
Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces
David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth
2015-04-01
We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.
International Nuclear Information System (INIS)
Lu Han-Han; Xu Jing-Ping; Liu Lu; Lai Pui-To; Tang Wing-Man
2016-01-01
An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C – V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi–Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. (paper)
Trautmann, N.; Hauke, P.
2018-02-01
The transport of excitations governs fundamental properties of matter. Particularly rich physics emerges in the interplay between disorder and environmental noise, even in small systems such as photosynthetic biomolecules. Counterintuitively, noise can enhance coherent quantum transport, which has been proposed as a mechanism behind the high transport efficiencies observed in photosynthetic complexes. This effect has been called "environment-assisted quantum transport". Here, we propose a quantum simulation of the excitation transport in an open quantum network, taking advantage of the high controllability of current trapped-ion experiments. Our scheme allows for the controlled study of various different aspects of the excitation transfer, ranging from the influence of static disorder and interaction range, over the effect of Markovian and non-Markovian dephasing, to the impact of a continuous insertion of excitations. Our paper discusses experimental error sources and realistic parameters, showing that it can be implemented in state-of-the-art ion-chain experiments.
Surgical management of common bile duct stones at Saint Paul's ...
African Journals Online (AJOL)
Background: This study was aimed at evaluating the trend and outcome of surgical management of choledocholithiasis in St. Paul Teaching Hospital Addis Ababa, Ethiopia. Methods: This was a clinical based retrospective analysis. The operation register was used to identify the cases that were operated for biliary lithiasis.
A School-Based Enterprise: The Saint Pauls, North Carolina Experience.
Paquin, Thomas F.
1991-01-01
The superintendent of Saint Pauls Schools describes how educators, community leaders, businesspersons, and high school students worked together to develop the Way Off Broadway Deli, a successful school-based enterprise providing experiential education in entrepreneurship and small business management, as well as student employment and local…
Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong
2017-01-01
Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.
Truncated RAP-MUSIC (TRAP-MUSIC) for MEG and EEG source localization.
Mäkelä, Niko; Stenroos, Matti; Sarvas, Jukka; Ilmoniemi, Risto J
2018-02-15
Electrically active brain regions can be located applying MUltiple SIgnal Classification (MUSIC) on magneto- or electroencephalographic (MEG; EEG) data. We introduce a new MUSIC method, called truncated recursively-applied-and-projected MUSIC (TRAP-MUSIC). It corrects a hidden deficiency of the conventional RAP-MUSIC algorithm, which prevents estimation of the true number of brain-signal sources accurately. The correction is done by applying a sequential dimension reduction to the signal-subspace projection. We show that TRAP-MUSIC significantly improves the performance of MUSIC-type localization; in particular, it successfully and robustly locates active brain regions and estimates their number. We compare TRAP-MUSIC and RAP-MUSIC in simulations with varying key parameters, e.g., signal-to-noise ratio, correlation between source time-courses, and initial estimate for the dimension of the signal space. In addition, we validate TRAP-MUSIC with measured MEG data. We suggest that with the proposed TRAP-MUSIC method, MUSIC-type localization could become more reliable and suitable for various online and offline MEG and EEG applications. Copyright © 2017 Elsevier Inc. All rights reserved.
Characteristics of trapped electrons and electron traps in single crystals
International Nuclear Information System (INIS)
Budzinski, E.E.; Potter, W.R.; Potienko, G.; Box, H.C.
1979-01-01
Two additional carbohydrates are reported whose crystal structures trap electrons intermolecularly in single crystals x irradiated at low temperature, namely sucrose and rhamnose. Five carbohydrate and polyhydroxy compounds are now known which exhibit this phenomenon. The following characteristics of the phenomenon were investigated: (1) the hyperfine couplings of the electron with protons of the polarized hydroxy groups forming the trap; (2) the distances between these protons and the trapped electron; (3) the spin density of the electron at the protons and (4) the relative stabilities of the electron trapped in various crystal structures
[Rethinking ethics with Paul Ricœur. Nursing: between responsibility, care and justice].
Svandra, Philippe
2016-03-01
In this article, the purpose is less praising Paul Ricoeur's work than enlightening how the reader may actually find some practical, even operative help in this philosophical thought. This is particularly true regarding the fields of medicine and care. Paul Ricœur is now worldwide renowned as a major philosophical figure of the 20th century, and with books such as "Oneself as another", he occupies a very peculiar place at the crossroads of phenomenology and hermeneutics. Through both these philosophical traditions, Paul Ricœur offers some narrative ethics which may greatly sustain caregivers in their reflexion. Yet, the aim of this article is to focus on this philosopher who invites us to inhabit and play a role in this world. The goal is also to bring out the pragmatic ethics that this thinker developed, based on Aristotelian and Kantian traditions. Then, this piece seeks to demonstrate how the three stages of Ricoeur's "petite éthique" (his "small ethics"), which are the self's aim "for the good life with and for others in just institutions" can shed some light on the ethical consideration of politicals and caregivers.
New Technique for Improving Performance of LDPC Codes in the Presence of Trapping Sets
Directory of Open Access Journals (Sweden)
Mohamed Adnan Landolsi
2008-06-01
Full Text Available Trapping sets are considered the primary factor for degrading the performance of low-density parity-check (LDPC codes in the error-floor region. The effect of trapping sets on the performance of an LDPC code becomes worse as the code size decreases. One approach to tackle this problem is to minimize trapping sets during LDPC code design. However, while trapping sets can be reduced, their complete elimination is infeasible due to the presence of cycles in the underlying LDPC code bipartite graph. In this work, we introduce a new technique based on trapping sets neutralization to minimize the negative effect of trapping sets under belief propagation (BP decoding. Simulation results for random, progressive edge growth (PEG and MacKay LDPC codes demonstrate the effectiveness of the proposed technique. The hardware cost of the proposed technique is also shown to be minimal.
Improving Success in Developmental Mathematics: An Interview with Paul Nolting
Boylan, Hunter R.
2011-01-01
This article presents an interview with Dr. Paul Nolting, a national expert in assessing individual math learning problems, developing effective student learning strategies, and assessing institutional variables that affect math success. Since his dissertation in 1986 on improving math success with study skills Dr. Nolting has consulted with over…
The Italian origins of FAO and Paul Otlet
Guarasci, Roberto; Taverniti, Maria
2016-01-01
Nowadays the strategic role of international organizations, which manage and provide information systems and library services in the agricultural domain, is universally recognized. This paper focuses on the origin of the Food and Agriculture Organization of the United Nations (FAO) by presenting a critical edition of the Rapport by Paul Otlet to the marquis Cappelli, pr?sident de l?Institut International d?Agricolture (Otlet, 1911) that includes original documents and outlines the first steps...
Simulations and experiments on RITA-2 at PSI
DEFF Research Database (Denmark)
Klausen, S.N.; Lefmann, K.; McMorrow, D.F.
2002-01-01
The cold-neutron triple-axis spectrometer RITA-2 designed and built at Riso National Laboratory was installed at the neutron source SINQ at Paul Scherrer Institute in April/May 2001. In connection with the installation of RITA-2, computer simulations were performed using the neutron ray...
EnviroAtlas - Minneapolis/St. Paul, MN - BenMAP Results by Block Group
U.S. Environmental Protection Agency — This EnviroAtlas dataset demonstrates the effect of changes in pollution concentration on local populations in 1,772 block groups in Minneapolis/St. Paul, Minnesota....
Quantum-enhanced deliberation of learning agents using trapped ions
International Nuclear Information System (INIS)
Dunjko, V; Friis, N; Briegel, H J
2015-01-01
A scheme that successfully employs quantum mechanics in the design of autonomous learning agents has recently been reported in the context of the projective simulation (PS) model for artificial intelligence. In that approach, the key feature of a PS agent, a specific type of memory which is explored via random walks, was shown to be amenable to quantization, allowing for a speed-up. In this work we propose an implementation of such classical and quantum agents in systems of trapped ions. We employ a generic construction by which the classical agents are ‘upgraded’ to their quantum counterparts by a nested process of adding coherent control, and we outline how this construction can be realized in ion traps. Our results provide a flexible modular architecture for the design of PS agents. Furthermore, we present numerical simulations of simple PS agents which analyze the robustness of our proposal under certain noise models. (paper)
Trap array configuration influences estimates and precision of black bear density and abundance.
Directory of Open Access Journals (Sweden)
Clay M Wilton
Full Text Available Spatial capture-recapture (SCR models have advanced our ability to estimate population density for wide ranging animals by explicitly incorporating individual movement. Though these models are more robust to various spatial sampling designs, few studies have empirically tested different large-scale trap configurations using SCR models. We investigated how extent of trap coverage and trap spacing affects precision and accuracy of SCR parameters, implementing models using the R package secr. We tested two trapping scenarios, one spatially extensive and one intensive, using black bear (Ursus americanus DNA data from hair snare arrays in south-central Missouri, USA. We also examined the influence that adding a second, lower barbed-wire strand to snares had on quantity and spatial distribution of detections. We simulated trapping data to test bias in density estimates of each configuration under a range of density and detection parameter values. Field data showed that using multiple arrays with intensive snare coverage produced more detections of more individuals than extensive coverage. Consequently, density and detection parameters were more precise for the intensive design. Density was estimated as 1.7 bears per 100 km2 and was 5.5 times greater than that under extensive sampling. Abundance was 279 (95% CI = 193-406 bears in the 16,812 km2 study area. Excluding detections from the lower strand resulted in the loss of 35 detections, 14 unique bears, and the largest recorded movement between snares. All simulations showed low bias for density under both configurations. Results demonstrated that in low density populations with non-uniform distribution of population density, optimizing the tradeoff among snare spacing, coverage, and sample size is of critical importance to estimating parameters with high precision and accuracy. With limited resources, allocating available traps to multiple arrays with intensive trap spacing increased the amount of
Configuration analysis and optimization on multipolar Galatea trap
Energy Technology Data Exchange (ETDEWEB)
Tong, W. M., E-mail: dianqi@hit.edu.cn; Tao, B. Q.; Jin, X. J.; Li, Z. W. [Harbin Institute of Technology, School of Electrical Engineering and Automation (China)
2016-10-15
Multipolar Galatea magnetic trap simulation model was established with the finite element simulation software COMSOL Multiphysics. Analyses about the magnetic section configuration show that better magnetic configuration should make more plasma stay in the weak magnetic field rather than the annular magnetic shell field. Then an optimization model was established with axial electromagnetic force, weak magnetic field area and average magnetic mirror ratio as the optimization goals and with the currents of myxines as design variables. Select appropriate weight coefficients and get optimization results by applying genetic algorithm. Results show that the superiority of the target value of typical application parameters, including the average magnetic mirror can reduce more than 5%, the weak magnetic field area can increase at least 65%, at the same time, axial electromagnetic force acting on the outer myxines can be reduced to less than 50 N. Finally, the results were proved by COMSOL Multiphysics and the results proved the optimized magnetic trap configuration with more plasma in the weak magnetic field can reduce the plasma diffusion velocity and is more conducive for the constraint of plasma.
OSL sensitivity changes during single aliquot procedures: Computer simulations
DEFF Research Database (Denmark)
McKeever, S.W.S.; Agersnap Larsen, N.; Bøtter-Jensen, L.
1997-01-01
We present computer simulations of sensitivity changes obtained during single aliquot, regeneration procedures. The simulations indicate that the sensitivity changes are the combined result of shallow trap and deep trap effects. Four separate processes have been identified. Although procedures can...... be suggested to eliminate the shallow trap effects, it appears that the deep trap effects cannot be removed. The character of the sensitivity changes which result from these effects is seen to be dependent upon several external parameters, including the extent of bleaching of the OSL signal, the laboratory...
Cavity Cooling a Single Charged Levitated Nanosphere
Millen, J.; Fonseca, P. Z. G.; Mavrogordatos, T.; Monteiro, T. S.; Barker, P. F.
2015-03-01
Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres.
Trapping, self-trapping and the polaron family
International Nuclear Information System (INIS)
Stoneham, A M; Gavartin, J; Shluger, A L; Kimmel, A V; Ramo, D Munoz; Roennow, H M; Aeppli, G; Renner, C
2007-01-01
The earliest ideas of the polaron recognized that the coupling of an electron to ionic vibrations would affect its apparent mass and could effectively immobilize the carrier (self-trapping). We discuss how these basic ideas have been generalized to recognize new materials and new phenomena. First, there is an interplay between self-trapping and trapping associated with defects or with fluctuations in an amorphous solid. In high dielectric constant oxides, like HfO 2 , this leads to oxygen vacancies having as many as five charge states. In colossal magnetoresistance manganites, this interplay makes possible the scanning tunnelling microscopy (STM) observation of polarons. Second, excitons can self-trap and, by doing so, localize energy in ways that can modify the material properties. Third, new materials introduce new features, with polaron-related ideas emerging for uranium dioxide, gate dielectric oxides, Jahn-Teller systems, semiconducting polymers and biological systems. The phonon modes that initiate self-trapping can be quite different from the longitudinal optic modes usually assumed to dominate. Fourth, there are new phenomena, like possible magnetism in simple oxides, or with the evolution of short-lived polarons, like muons or excitons. The central idea remains that of a particle whose properties are modified by polarizing or deforming its host solid, sometimes profoundly. However, some of the simpler standard assumptions can give a limited, indeed misleading, description of real systems, with qualitative inconsistencies. We discuss representative cases for which theory and experiment can be compared in detail
Reframing Paul's sibling language in light of Jewish epistolary forms ...
African Journals Online (AJOL)
2015-06-17
Jun 17, 2015 ... Reframing Paul's sibling language in light of Jewish epistolary forms of ... believers including Gentiles signals the re-definition of the family of Abraham. Read online: ..... Thirdly, some significant differences are detected between. Jewish ..... Rome (Moxnes 1980:78), and that 'the weak' in faith in. Romans 14 ...
Schuster, Jonathan; Bellotti, Enrico
2013-06-01
We have investigated the quantum effiency in HgCdTe photovoltaic pixel arrays employing a photon-trapping structure realized with a periodic array of pillars intended to provide broadband operation. We have found that the quantum efficiency depends heavily on the passivation of the pillar surface. Pillars passivated with anodicoxide have a large fixed positive charge on the pillar surface. We use our three-dimensional numerical simulation model to study the effect of surface charge and surface recombination velocity on the exterior of the pillars. We then evaluate the quantum efficiency of this structure subject to different surface conditions. We have found that by themselves, the surface charge and surface recombination are detrimental to the quantum efficiency but the quantum efficiency is recovered when both phenomena are present. We will discuss the effects of these phenomena and the trade offs that exist between the two.
Trapping and cooling of rf-dressed atoms in a quadrupole magnetic field
International Nuclear Information System (INIS)
Morizot, O; Alzar, C L Garrido; Pottie, P-E; Lorent, V; Perrin, H
2007-01-01
We observe the spontaneous evaporation of atoms confined in a bubble-like radio frequency (rf)-dressed trap (Zobay and Garraway 2001 Phys. Rev. Lett. 86 1195; 2004 Phys. Rev. A 69 023605). The atoms are confined in a quadrupole magnetic trap and are dressed by a linearly polarized rf field. The evaporation is related to the presence of holes in the trap, at the positions where the rf coupling vanishes, due to its vectorial character. The final temperature results from a competition between residual heating and evaporation efficiency, which is controlled via the height of the holes with respect to the bottom of the trap. The experimental data are modelled by a Monte Carlo simulation predicting a small increase in phase-space density limited by the heating rate. This increase was within the phase-space density determination uncertainty of the experiment
Assimilating to Power in Two Different World-Systems: An Analysis of Paul and Herzl
Directory of Open Access Journals (Sweden)
Khaldoun Samman
2015-08-01
Full Text Available This essay concerns two Jewish men from different historical formations: the Apostle Paul, a Jew living in the Roman Empire in the first century and one of the founding figures of Christianity, and Theodor Herzl, a Jew living in late-nineteenth-century Austria and the founding father of Zionism, a Jewish nationalist movement. My central argument is that both men employed an assimilationist strategy that linked their identity to powerful social forces of their time, strategically restructuring their identity so that they could move into the most powerful centers of their social systemPaul navigating himself towards Rome and Herzl setting his gaze west even while physically moving east. My objective here is to demonstrate how these two Jewish figures used Christianity and Zionism, respectively, to assimilate towards those who hold real power, each of them appropriating the ideology of his movement in order to join the most powerful sector of his world. Yet I also intend to demonstrate that, while they both shared a desire to assimilate to power, the strategies they implemented to reach their goals were radically different: Paul using a universalistic discourse, what I shall call Israel in the spirit, whereas Herzl chose the particularistic discourse of Israel in the flesh. This is due, I argue, to the fact that both of these great historical figures were reacting to the social and political forces of their times, Paul to the centripetal forces of ancient world-empires and Herzl to the centrifugal forces of the modern world-system.
Directory of Open Access Journals (Sweden)
Rosana Costa Ramalho de Castro
2010-01-01
Full Text Available Estudo sobre a Teoria da Forma concebida no início do século XX pelo artista plástico Paul Klee e publicado no livro O Pensamento Criativo (KLEE, 1920. A Teoria da Forma de Paul Klee é uma demonstração do pensamento artístico que adota pressupostos formais, previamente estabelecidos para resultar na prática da representação artística. Klee identificou as relações formais entre a música e as artes visuais, apresentando conexões entre a linha melódica e a linha no desenho; o ritmo e as seqüências de módulos e sub-módulos; os tempos dos compassos e as divisões da pintura; a métrica da música e a modulação da forma e da cor nas artes visuais. Klee também apresentou suas experiências com superposição de cores e texturas para representar visualmente a polifonia. A Teoria da Forma de Paul Klee é um exemplo de estudo que pressupõe modelos formais para a elaboração artística e projetual.Study on the Theory of Form conceived in the early twentieth century by artist Paul Klee and published in the book The Creative Thinking (KLEE, 1920. The Theory of Form of Paul Klee is a demonstration of an artistic thought that adopts the previously established formal prerequisites that result in the practice of artistic representation. Klee identified the formal relationship between music and the visual arts, providing connections between the melodic line and the line in the drawing, rhythm and sequence of modules and sub-modules, the pulses of the measures and the divisions of the painting, metrics in music and the modulation of shape and color in the visual arts. Klee also presented his experiences with overlapping colors and textures to visually represent polyphony. The Theory of Form of Paul Klee is an example of a study that requires formal models for the artistic and design elaboration.
Lonner, Walter J; Draguns, Juris G
2018-01-01
Presents an obituary for Paul B. Pedersen, who passed away on January 11, 2017, in a Minnetonka, Minnesota hospital. In 1973 Pedersen convened a pathfinding APA (Division 9) symposium in Montreal that resulted in the publication in 1976 of Counseling Across Cultures (Pedersen, Lonner, and Draguns, Eds.). The first book of its kind, it became the "Granddaddy" of all subsequent books in that area. The seventh edition, published in 2016 (with Trimble and Scharron-del Rio, co-eds), benefitted from his steadfast encouragement, but his deteriorating health prevented a more active role. His epitaph may well be one of his wisest and oft-quoted sayings: "All interviewing and counseling is multicultural. Each client comes to the session embodying multiple voices from the past." (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Paths to light trapping in thin film GaAs solar cells.
Xiao, Jianling; Fang, Hanlin; Su, Rongbin; Li, Kezheng; Song, Jindong; Krauss, Thomas F; Li, Juntao; Martins, Emiliano R
2018-03-19
It is now well established that light trapping is an essential element of thin film solar cell design. Numerous light trapping geometries have already been applied to thin film cells, especially to silicon-based devices. Less attention has been paid to light trapping in GaAs thin film cells, mainly because light trapping is considered less attractive due to the material's direct bandgap and the fact that GaAs suffers from strong surface recombination, which particularly affects etched nanostructures. Here, we study light trapping structures that are implemented in a high-bandgap material on the back of the GaAs active layer, thereby not perturbing the integrity of the GaAs active layer. We study photonic crystal and quasi-random nanostructures both by simulation and by experiment and find that the photonic crystal structures are superior because they exhibit fewer but stronger resonances that are better matched to the narrow wavelength range where GaAs benefits from light trapping. In fact, we show that a 1500 nm thick cell with photonic crystals achieves the same short circuit current as an unpatterned 4000 nm thick cell. These findings are significant because they afford a sizeable reduction in active layer thickness, and therefore a reduction in expensive epitaxial growth time and cost, yet without compromising performance.
A multidimensional theory for electron trapping by a plasma wake generated in the bubble regime
International Nuclear Information System (INIS)
Kostyukov, I; Nerush, E; Pukhov, A; Seredov, V
2010-01-01
We present a theory for electron self-injection in nonlinear, multidimensional plasma waves excited by a short laser pulse in the bubble regime or by a short electron beam in the blowout regime. In these regimes, which are typical for electron acceleration in the last impressive experiments, the laser radiation pressure or the electron beam charge pushes out plasma electrons from some region, forming a plasma cavity or a bubble with a huge ion charge. The plasma electrons can be trapped in the bubble and accelerated by the plasma wakefields up to a very high energy. We derive the condition of the electron trapping in the bubble. The developed theory predicts the trapping cross section in terms of the bubble radius and the bubble velocity. It is found that the dynamic bubble deformations observed in the three-dimensional (3D) particle-in-cell (PIC) simulations influence the trapping process significantly. The bubble elongation reduces the gamma-factor of the bubble, thereby strongly enhancing self-injection. The obtained analytical results are in good agreement with the 3D PIC simulations.
Recovering Philosophy as the Love of Wisdom: A Contribution of St. John Paul II
Directory of Open Access Journals (Sweden)
Pawel Tarasiewicz
2016-03-01
Full Text Available The article aims at demonstrating that, by his teaching on human person and his action, St. John Paul II (also known as Karol Wojtyła implicitly contributed to a resolution of the most serious problem of contemporary philosophy, which consists in separating wisdom from love and substituting wisdom with understanding or knowledge. The author concludes that John Paul II makes a persuasive contribution to recover philosophy as the love of wisdom by (1 identifying truth in the area of freedom, self-fulfillment and conscience, and (2 appealing to man’s honesty and happiness.
Numerical Analysis of Hydrodynamic Flow in Microfluidic Biochip for Single-Cell Trapping Application
Directory of Open Access Journals (Sweden)
Amelia Ahmad Khalili
2015-11-01
Full Text Available Single-cell analysis has become the interest of a wide range of biological and biomedical engineering research. It could provide precise information on individual cells, leading to important knowledge regarding human diseases. To perform single-cell analysis, it is crucial to isolate the individual cells before further manipulation is carried out. Recently, microfluidic biochips have been widely used for cell trapping and single cell analysis, such as mechanical and electrical detection. This work focuses on developing a finite element simulation model of single-cell trapping system for any types of cells or particles based on the hydrodynamic flow resistance (Rh manipulations in the main channel and trap channel to achieve successful trapping. Analysis is carried out using finite element ABAQUS-FEA™ software. A guideline to design and optimize single-cell trapping model is proposed and the example of a thorough optimization analysis is carried out using a yeast cell model. The results show the finite element model is able to trap a single cell inside the fluidic environment. Fluid’s velocity profile and streamline plots for successful and unsuccessful single yeast cell trapping are presented according to the hydrodynamic concept. The single-cell trapping model can be a significant important guideline in designing a new chip for biomedical applications.
REvISITING PAul'S PARAdIGMATIC, SElf-CRITICAl REMARkS IN 1 ...
African Journals Online (AJOL)
However, in 1 Corinthians 15:8-10 Paul openly admits about being in error in the past ..... Much has been written about the expression e[ktrwma in verse 8. This .... Collins 2008:120- .... The Gospel of John in cultural and rhetorical perspective.
the lukan periplus of paul's third journey with a textual conundrum
African Journals Online (AJOL)
convenience of the few fee-paying passengers. to Jerusalem. Paul does ... starts to warn him of the danger ahead in Jerusalem, which probably occurred in Troas ... conduct business along the way at their nightly ports of call. 2.2 The genre of ...
Tunable potential well for plasmonic trapping of metallic particles by bowtie nano-apertures.
Lu, Yu; Du, Guangqing; Chen, Feng; Yang, Qing; Bian, Hao; Yong, Jiale; Hou, Xun
2016-09-26
In this paper, the tunable optical trapping dependence on wavelength of incident beam is theoretically investigated based on numerical simulations. The Monte Carlo method is taken into account for exploring the trapping characteristics such as average deviation and number distribution histogram of nanoparticles. It is revealed that both the width and the depth of potential well for trapping particles can be flexibly adjusted by tuning the wavelength of the incident beam. In addition, incident wavelengths for the deepest potential well and for the strongest stiffness at bottom are separated. These phenomena are explained as the strong plasmon coupling between tweezers and metallic nanoparticles. In addition, required trapping fluence and particles' distributions show distinctive properties through carefully modifying the incident wavelengths from 1280 nm to 1300 nm. Trapping with lowest laser fluence can be realized with 1280 nm laser and trapping with highest precision can be realized with 1300 nm laser. This work will provide theoretical support for advancing the manipulation of metallic particles and related applications such as single-molecule fluorescence and surface enhanced Raman spectroscopy.
Narrative Refiguration of Social Events: Paul Ricoeur's Contribution to Rethinking the Social
Directory of Open Access Journals (Sweden)
Anna Borisenkova
2010-12-01
Full Text Available The analysis of events has been a central issue for social sciences for a long time. The problem of an event's definition and distinction is still at stake in sociological debates. The purpose of this paper is to demonstrate the contribution of Paul Ricoeur's narrative theory to social events studies. First, this is done through the explication of the concept in the framework of narrative approach. Secondly, the paper highlights the narrative's capacity of 'refiguring' the social by re-describing social events, subordinating their succession to the logic of story-telling and transforming temporal characteristics as well. Apart from some insights, interpretative explanations and illustrations the paper provides critical arguments concerning the limitations of Paul Ricoeur's narrative approach with respect to sociological event-analysis. L'analyse des événements a toujours été une question centrale pour l'histoire et les sciences sociales. Le problème de la définition et de la distinction des événements est encore en jeu dans les débats sociologiques contemporains. L'objectif de cet article est de s'attarder sur la contribution de la théorie de Paul Ricœur aux études des événements sociaux. Après avoir montré les limites d'une conception impersonnelle de l'événement, l'auteur se penche sur la solution narrative proposée par Ricœur, à savoir la capacité du récit à “refigurer” du Social par la re-description des événements sociaux. Il s'agit de soumettre la logique de la succession temporelle à la logique de la narration. Tout en rendant justice à la valeur heuristique de telles analyses (à travers une série d'explicitations et d'illustrations, l'article pointe les limites de l'approche narrative de Paul Ricœur au regard des analyses sociologique des événements.
Effect of trap position on the efficiency of trapping in treelike scale-free networks
International Nuclear Information System (INIS)
Zhang Zhongzhi; Lin Yuan; Ma Youjun
2011-01-01
The conventional wisdom is that the role and impact of nodes on dynamical processes in scale-free networks are not homogenous, because of the presence of highly connected nodes at the tail of their power-law degree distribution. In this paper, we explore the influence of different nodes as traps on the trapping efficiency of the trapping problem taking place on scale-free networks. To this end, we study in detail the trapping problem in two families of deterministically growing scale-free networks with treelike structure: one family is non-fractal, the other is fractal. In the first part of this work, we attack a special case of random walks on the two network families with a perfect trap located at a hub, i.e. node with the highest degree. The second study addresses the case with trap distributed uniformly over all nodes in the networks. For these two cases, we compute analytically the mean trapping time (MTT), a quantitative indicator characterizing the trapping efficiency of the trapping process. We show that in the non-fractal scale-free networks the MTT for both cases follows different scalings with the network order (number of network nodes), implying that trap's position has a significant effect on the trapping efficiency. In contrast, it is presented that for both cases in the fractal scale-free networks, the two leading scalings exhibit the same dependence on the network order, suggesting that the location of trap has no essential impact on the trapping efficiency. We also show that for both cases of the trapping problem, the trapping efficiency is more efficient in the non-fractal scale-free networks than in their fractal counterparts.
Ruspini, L. C.; Farokhpoor, R.; Øren, P. E.
2017-10-01
We present a pore-network model study of capillary trapping in water-wet porous media. The amount and distribution of trapped non-wetting phase is determined by the competition between two trapping mechanisms - snap-off and cooperative pore-body filling. We develop a new model to describe the pore-body filling mechanism in geologically realistic pore-networks. The model accounts for the geometrical characteristics of the pore, the spatial location of the connecting throats and the local fluid topology at the time of the displacement. We validate the model by comparing computed capillary trapping curves with published data for four different water-wet rocks. Computations are performed on pore-networks extracted from micro-CT images and process-based reconstructions of the actual rocks used in the experiments. Compared with commonly used stochastic models, the new model describes more accurately the experimental measurements, especially for well connected porous systems where trapping is controlled by subtleties of the pore structure. The new model successfully predicts relative permeabilities and residual saturation for Bentheimer sandstone using in-situ measured contact angles as input to the simulations. The simulated trapped cluster size distributions are compared with predictions from percolation theory.
Lin, Yuan; Zhang, Zhongzhi
2013-03-07
The trapping process in polymer systems constitutes a fundamental mechanism for various other dynamical processes taking place in these systems. In this paper, we study the trapping problem in two representative polymer networks, Cayley trees and Vicsek fractals, which separately model dendrimers and regular hyperbranched polymers. Our goal is to explore the impact of trap location on the efficiency of trapping in these two important polymer systems, with the efficiency being measured by the average trapping time (ATT) that is the average of source-to-trap mean first-passage time over every staring point in the whole networks. For Cayley trees, we derive an exact analytic formula for the ATT to an arbitrary trap node, based on which we further obtain the explicit expression of ATT for the case that the trap is uniformly distributed. For Vicsek fractals, we provide the closed-form solution for ATT to a peripheral node farthest from the central node, as well as the numerical solutions for the case when the trap is placed on other nodes. Moreover, we derive the exact formula for the ATT corresponding to the trapping problem when the trap has a uniform distribution over all nodes. Our results show that the influence of trap location on the trapping efficiency is completely different for the two polymer networks. In Cayley trees, the leading scaling of ATT increases with the shortest distance between the trap and the central node, implying that trap's position has an essential impact on the trapping efficiency; while in Vicsek fractals, the effect of location of the trap is negligible, since the dominant behavior of ATT is identical, respective of the location where the trap is placed. We also present that for all cases of trapping problems being studied, the trapping process is more efficient in Cayley trees than in Vicsek fractals. We demonstrate that all differences related to trapping in the two polymer systems are rooted in their underlying topological structures.
Jorgensen, L V; Bertsche, W; Boston, A; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hayano, R S; Hydomako, R; Jenkins, M J; Kurchaninov, L; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page, R D; Povilus, A; Robicheaux, F; Sarid, E; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki, Y
2008-01-01
Substantial progress has been made in the last few years in the nascent field of antihydrogen physics. The next big step forward is expected to be the trapping of the formed antihydrogen atoms using a magnetic multipole trap. ALPHA is a new international project that started to take data in 2006 at CERN’s Antiproton Decelerator facility. The primary goal of ALPHA is stable trapping of cold antihydrogen atoms to facilitate measurements of its properties. We discuss the status of the ALPHA project and the prospects for antihydrogen trapping.
Li, Chen; Zhou, Tianwei; Zhai, Yueyang; Xiang, Jinggang; Luan, Tian; Huang, Qi; Yang, Shifeng; Xiong, Wei; Chen, Xuzong
2017-05-01
We report a setup for the deep cooling of atoms in an optical trap. The deep cooling is implemented by eliminating the influence of gravity using specially constructed magnetic coils. Compared to the conventional method of generating a magnetic levitating force, the lower trap frequency achieved in our setup provides a lower limit of temperature and more freedoms to Bose gases with a simpler solution. A final temperature as low as ˜ 6 nK is achieved in the optical trap, and the atomic density is decreased by nearly two orders of magnitude during the second stage of evaporative cooling. This deep cooling of optically trapped atoms holds promise for many applications, such as atomic interferometers, atomic gyroscopes, and magnetometers, as well as many basic scientific research directions, such as quantum simulations and atom optics.
International Nuclear Information System (INIS)
Ho Quang Quy; Mai Van Luu; Hoang Dinh Hai
2010-01-01
In this article the gradient force of optical trap using two counter- propagating pulsed Gaussian beam and the Brownian motion in optical force field are investigated. The influence of the energy and duration time of optical pulsed Gaussian beams on stability of nano-particle in trap is simulated and discussed. (author)
Two-species mixing in a nested Penning trap for antihydrogen trapping
International Nuclear Information System (INIS)
Ordonez, C. A.; Weathers, D. L.
2008-01-01
There exists an international quest to trap neutral antimatter in the form of antihydrogen for scientific study. One method that is being developed for trapping antihydrogen employs a nested Penning trap. Such a trap serves to mix positrons and antiprotons so as to produce low energy antihydrogen atoms. Mixing is achieved when the confinement volumes of the two species overlap one another. In the work presented here, a theoretical understanding of the mixing process is developed by analyzing a mixing scheme that was recently reported [G. Gabrielse et al., Phys. Rev. Lett. 100, 113001 (2008)]. The results indicate that positron space charge or collisions among antiprotons may substantially reduce the fraction of antiprotons that have an energy suitable for antihydrogen trapping
Formation of Antihydrogen Rydberg atoms in strong magnetic field traps
International Nuclear Information System (INIS)
Pohl, T.; Sadeghpour, H. R.
2008-01-01
It is shown that several features of antihydrogen production in nested Penning traps can be described with accurate and efficient Monte Carlo simulations. It is found that cold deeply-bound Rydberg states of antihydrogen (H-bar) are produced in three-body capture in the ATRAP experiments and an additional formation mechanism -Rydberg charge transfer-, particular to the nested Penning trap geometry, is responsible for the observed fast (hot) H-bar atoms. Detailed description of the numerical propagation technique for following extreme close encounters is given. An analytic derivation of the power law behavior of the field ionization spectrum is provided
Lu, Han-Han; Xu, Jing-Ping; Liu, Lu; Lai, Pui-To; Tang, Wing-Man
2016-11-01
An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi-Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. Project supported by the National Natural Science Foundation of China (Grant Nos. 61176100 and 61274112), the University Development Fund of the University of Hong Kong, China (Grant No. 00600009), and the Hong Kong Polytechnic University, China (Grant No. 1-ZVB1).
Dawson, Heather; Jones, Michael L.; Irwin, Brian J.; Johnson, Nicholas; Wagner, Michael C.; Szymanski, Melissa
2016-01-01
We applied a management strategy evaluation (MSE) model to examine the potential cost-effectiveness of using pheromone-baited trapping along with conventional lampricide treatment to manage invasive sea lamprey. Four pheromone-baited trapping strategies were modeled: (1) stream activation wherein pheromone was applied to existing traps to achieve 10−12 mol/L in-stream concentration, (2) stream activation plus two additional traps downstream with pheromone applied at 2.5 mg/hr (reverse-intercept approach), (3) trap activation wherein pheromone was applied at 10 mg/hr to existing traps, and (4) trap activation and reverse-intercept approach. Each new strategy was applied, with remaining funds applied to conventional lampricide control. Simulating deployment of these hybrid strategies on fourteen Lake Michigan streams resulted in increases of 17 and 11% (strategies 1 and 2) and decreases of 4 and 7% (strategies 3 and 4) of the lakewide mean abundance of adult sea lamprey relative to status quo. MSE revealed performance targets for trap efficacy to guide additional research because results indicate that combining lampricides and high efficacy trapping technologies can reduce sea lamprey abundance on average without increasing control costs.
Schmeisser, Gerhard
2014-01-01
Paul Butzer, who is considered the academic father and grandfather of many prominent mathematicians, has established one of the best schools in approximation and sampling theory in the world. He is one of the leading figures in approximation, sampling theory, and harmonic analysis. Although on April 15, 2013, Paul Butzer turned 85 years old, remarkably, he is still an active research mathematician. In celebration of Paul Butzer’s 85th birthday, New Perspectives on Approximation and Sampling Theory is a collection of invited chapters on approximation, sampling, and harmonic analysis written by students, friends, colleagues, and prominent active mathematicians. Topics covered include approximation methods using wavelets, multi-scale analysis, frames, and special functions. New Perspectives on Approximation and Sampling Theory requires basic knowledge of mathematical analysis, but efforts were made to keep the exposition clear and the chapters self-contained. This volume will appeal to researchers and graduate...
Passings to note: Paul Michael Packman, MD; S. Charles Schulz, MD.
Black, Donald W
2018-02-01
One of the keys to the success of Annals of Clinical Psychiatry has always been the tireless efforts of our dedicated Editorial Board. We recently lost 2 longtime Editorial Board members, Drs. Paul Michael Packman and S. Charles Schulz. Both will be greatly missed.
Paul Valery: Un canto de frontera
Directory of Open Access Journals (Sweden)
Eduardo Carranza
1966-09-01
Full Text Available Paul Valery nació en Cette el 30 de octubre de 1871, de padre francés y de madre italiana. Hizo sus primeros estudios en un colegio de su pequeña ciudad natal y realizó luego con sus padres un viaje infantil a París y a Londres. En 1884 siguió los cursos del Colegio de Montpellier. Pasaba sus vacaciones en Génova con los suyos, circunstancia que incorporó a su espíritu una estela de reminiscencias italianas. Siguió luego cursos en la Facultad de Derecho y, ya en el umbral de la primera juventud, vacilaba ante la escogencia de su destino.
Ion trapping within the dust grain plasma sheath
International Nuclear Information System (INIS)
Jovanovic, D.; Shukla, P.K.
2002-01-01
One of the most important and still unresolved problems in the physics of dusty plasmas is the determination of the dust charge. The grains are not directly accessible to measurements and it is necessary to have a reliable theoretical model of the electron and ion dynamics inside the Debye sphere for the interpretation of the relevant experimental data, which include also the effects of the surrounding electron and ion clouds. Recent computer simulations [6] and laboratory experiments [9] indicate that the plasma sheath is dominated by trapped ions, orbiting the grain on closed trajectories at distances smaller than the Debye radius, that cannot be accounted for by the classical theories. We present the first analytical, fully self-consistent, calculations of the electrostatic shielding of a charged dust grain in a collisional plasma. In the regime when the mean free path for the ion-dust collisions is larger than that for the ion-neutral collisions, we solve the kinetic equation for the ions, coupled with Boltzmann distributed electrons and Poisson's equation. The ion velocity distribution function, in the form of a spherically symmetric ion hole, is found to be anisotropic in the presence of charge-exchange collisions. The number of trapped ions and their spatial distribution are determined from the interplay between the collective plasma interaction and the collisional trapping/de-trapping. The stationary state results from the self-tuning of the trapped ion density by the feedback based on the nonlocality of the collisional integral, and on the ion mixing in the radial direction along elongated orbits. Our results confirm the existence of a strong Debye shielding of the dust charge, allowing also the over-population of the trapped ion distribution (ion hump)
Status and outlook of CHIP-TRAP: The Central Michigan University high precision Penning trap
Redshaw, M.; Bryce, R. A.; Hawks, P.; Gamage, N. D.; Hunt, C.; Kandegedara, R. M. E. B.; Ratnayake, I. S.; Sharp, L.
2016-06-01
At Central Michigan University we are developing a high-precision Penning trap mass spectrometer (CHIP-TRAP) that will focus on measurements with long-lived radioactive isotopes. CHIP-TRAP will consist of a pair of hyperbolic precision-measurement Penning traps, and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced by external ion sources, including a laser ablation source, and transported to the capture trap at low energies enabling ions of a given m / q ratio to be selected via their time-of-flight. In the capture trap, contaminant ions will be removed with a mass-selective rf dipole excitation and the ion of interest will be transported to the measurement traps. A phase-sensitive image charge detection technique will be used for simultaneous cyclotron frequency measurements on single ions in the two precision traps, resulting in a reduction in statistical uncertainty due to magnetic field fluctuations.
Evaluation method for acoustic trapping performance by tracking motion of trapped microparticle
Lim, Hae Gyun; Ham Kim, Hyung; Yoon, Changhan
2018-05-01
We report a method to evaluate the performances of a single-beam acoustic tweezer using a high-frequency ultrasound transducer. The motion of a microparticle trapped by a 45-MHz single-element transducer was captured and analyzed to deduce the magnitude of trapping force. In the proposed method, the motion of a trapped microparticle was analyzed from a series of microscopy images to compute trapping force; thus, no additional equipment such as microfluidics is required. The method could be used to estimate the effective trapping force in an acoustic tweezer experiment to assess cell membrane deformability by attaching a microbead to the surface of a cell and tracking the motion of the trapped bead, which is similar to a bead-based assay that uses optical tweezers. The results showed that the trapping force increased with increasing acoustic intensity and duty factor, but the force eventually reached a plateau at a higher acoustic intensity. They demonstrated that this method could be used as a simple tool to evaluate the performance and to optimize the operating conditions of acoustic tweezers.
Ab initio determination of ion traps and the dynamics of silver in silver-doped chalcogenide glass
International Nuclear Information System (INIS)
Chaudhuri, I.; Inam, F.; Drabold, D. A.
2009-01-01
We present a microscopic picture of silver dynamics in GeSe 3 :Ag glass obtained from the ab initio simulation. The dynamics of Ag is explored at two temperatures: 300 and 700 K. In the relaxed network, Ag occupies trapping centers that exist between suitably separated host sites. At 700 K, Ag motion proceeds via a trapping-release dynamics between 'supertraps' or cages consisting of multiple trapping center sites in a small volume. Our work offers a first-principles identification of trapping centers invoked in current theories, with a description of their properties and associated Ag dynamics. We compute the charge state of the Ag in the network and show that it is neutral if weakly bonded and Ag + if in a trapping center
Calibration Laboratory of the Paul Scherrer Institute
International Nuclear Information System (INIS)
Gmuer, K.; Wernli, C.
1994-01-01
Calibration and working checks of radiation protection instruments are carried out at the Calibration Laboratory of the Paul Scherrer Institute. In view of the new radiation protection regulation, the calibration laboratory received an official federal status. The accreditation procedure in cooperation with the Federal Office of Metrology enabled a critical review of the techniques and methods applied. Specifically, personal responsibilities, time intervals for recalibration of standard instruments, maximum permissible errors of verification, traceability and accuracy of the standard instruments, form and content of the certificates were defined, and the traceability of the standards and quality assurance were reconsidered. (orig.) [de
Calcium Atom Trap for Atom Trap Mass Spectrometer
Energy Technology Data Exchange (ETDEWEB)
Ko, Kwang Hoon; Park, Hyun Min; Han, Jae Min; Kim, Taek Soo; Cha, Yong Ho; Lim, Gwon; Jeong, Do Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2012-05-15
Trace isotope analysis has been an important role in science, archaeological dating, geology, biology and nuclear industry. Artificially produced fission products such as Sr-90, Cs-135 and Kr-85 can be released to the environment when nuclear accident occurs and the reprocessing factory operates. Thus, the analysis of them has been of interest in nuclear industry. But it is difficult to detect them due to low natural abundance less then 10-10. The ultra-trace radio isotopes have been analyzed by the radio-chemical method, accelerator mass spectrometer, and laser based method. The radiochemical method has been used in the nuclear industry. But this method has disadvantages of long measurement time for long lived radioisotopes and toxic chemical process for the purification. The accelerator mass spectrometer has high isotope selectivity, but the system is huge and it has the isobar effects. The laser based method, such as RIMS (Resonance Ionization Mass Spectrometry) is a basically isobar-effect free method. Recently, ATTA (Atom Trap Trace Analysis), one of the laser based method, has been successfully demonstrated sufficient isotope selectivity with small system size. It has been applied for the detection of Kr-81 and Kr-85. However, it is not suitable for real sample detection, because it requires steady atomic beam generation during detection and is not allowed simultaneous detection of other isotopes. Therefore, we proposed the coupled method of Atom Trap and Mass Spectrometer. It consists of three parts, neutral atom trap, ionization and mass spectrometer. In this paper, we present the demonstration of the magneto-optical trap of neutral calcium. We discuss the isotope selective characteristics of the MOT (Magneto Optical Trap) of calcium by the fluorescence measurement. In addition, the frequency stabilization of the trap beam will be presented
Paul of Aegina (ca 625-690 ad), Reconstructing Male Gynecomastia.
Tsoucalas, Gregory; Sgantzos, Markos
2017-06-01
Paul of Aegina thrived with his innovative operations, practically creating a kind of a new surgical school. He had deeply believed in human's body perfection introducing a series of cosmetic operations. Among them stood the male's breasts reconstruction in the case of pseudo-gynecomastia. His intervention was replicated by both the western Europeans and the Arabs.
Constancy of character and Paul's understanding of change in his ...
African Journals Online (AJOL)
2010-11-21
Nov 21, 2010 ... Paul's concern for explaining his own change in behaviour as positive and ... of fear of those of the circumcision (Gl 2:11–14), is not justified. ... have been changed by a divine call, and any further change of behaviour dishonours the divine ... Jewish Christians to which Betz appeals, as well as the idea that ...
Hindemith, Paul: "Complete sonatas for Solo Instrument and Piano" / Michel Roubinet
Roubinet, Michel
1997-01-01
Uuest heliplaadist "Hindemith, Paul: "Complete sonatas for Solo Instrument and Piano", vol. 6. Sonate pour trompette et piano. Sonates pour orgue nos 1 a 3. Sonate pour cor et piano. Ensemble Villa Musica: Kalle Randalu (piano)" MDG "Gold" 304 0696-2, distr. Media 7 (CD:160F)
Swiss synchrotron light source at the Paul Scherrer Institute at Villigen
International Nuclear Information System (INIS)
1996-02-01
The brochure describes the Swiss project for a synchrotron light source to be built at the Paul Scherrer Institute at Villigen. According to the project the synchrotron light source shall be realized up to the year 2001 at costs of 165 Million Swiss Francs. figs., tabs
The Paul Scherrer Institute, a multidisciplinary organization opened to the world
International Nuclear Information System (INIS)
Mayer, N.
2008-01-01
At the end of the second world war, the Swiss Federal Military department created a commission for the study of nuclear energy under the presidency of Paul Scherrer. This famous Swiss physicist was particularly interested in this new domain of physics and will be few years later one of the main actor of the creation of CERN, a European organization for nuclear research. Some financial problems and a nuclear accident in 1969 have blown away the dreams of a nuclear reactor entirely made in Switzerland. The Paul Scherrer Institute was born in this context in 1988 near Zurich. Twenty years later it employs about 1300 people with an operating budget of about 175 million euros financed at 85% by the Swiss confederation. This article presents the different domains of research of the institute, its infrastructures (X-ray, neutrons and muons probes), its technology transfer actions and the cooperations with France. (J.S.)
A live-trap and trapping technique for fossorial mammals
African Journals Online (AJOL)
mammals. G.C. Hickman. An effective live-trap was designed for Cryptomys hottentotus .... that there is an animal in the burrow system, and to lessen the likelihood of the .... the further testing and modification of existing trap types. Not only is it ...
Directory of Open Access Journals (Sweden)
Leal, Ivanhoé Albuquerque
2016-01-01
Full Text Available Analisamos uma das teses da teoria narrativa de Paul Ricoeur que concede ao discurso histórico a habilidade de configurar a experiência temporal humana, sempre exposta à trama de perspectivas cruzadas entre a expectativa do futuro, a recepção do passado e a vivência do presente. Face à multiplicidade do tempo, os lineamentos argumentativos ricoeurianos indicam o ato narrativo como a condição tanto de pensar a efetividade das ações humanas e sua reconstrução histórica, quanto de forjar uma unidade plural própria a uma consciência hermenêutica
Matthew, Paul and the origin and nature of the gentile mission: The ...
African Journals Online (AJOL)
p1243322
previous restriction of the mission to Israel alone and demands that the disciples .... The relationship between Matthew and Paul has never been at the forefront of. Matthean studies. For the ..... eat the children's' crumbs”. London: T & T Clark.
The Common Sense Personalism of St. John Paul II (Karol Wojtyła
Directory of Open Access Journals (Sweden)
Pawel Tarasiewicz
2014-12-01
Full Text Available The article aims at showing that the philosophical personalism of Pope John Paul II (Karol Wojtyla stems from the common sense approach to reality. First, it presents Karol Wojtyla as a framer of the Lublin Philosophical School, to which he was affiliated for 24 years before being elected Pope John Paul II; it shows Wojtyla’s role in establishing this original philosophical School by his contribution to its endorsement of Thomism, its way of doing philosophy, and its classically understood personalism. Secondly, it identifies a purpose of Wojtyla’s use of the phenomenological method in his personalism and reconstructs Wojtyla’s possible answer to the question whether there is a link between moral sense and common sense in human experience.
Mr Paul: Masculinity and Paul’s self-presentation (1 Cor 11–13
Directory of Open Access Journals (Sweden)
Jeremy Punt
2016-10-01
Full Text Available Notwithstanding all the corporeal and gendered language in the Pauline letters, the apostle’s bodiliness and masculinity so far has received little attention. In the 1st-century context masculinity reigned by default and provides the contemporary context for teasing out the corporeal and gendered overtones in the Pauline letters, especially in Paul’s self-presentation. Recent and intersecting masculinity studies, body theology and queer theory provide useful tools for engaging Paul as man and his bodily-focussed, gendered approach in his letters. A focus on both Paul as embodied man and his corporeal, gendered approach enable alternative readings of his letters’ concern with corporeality and the related relationships between bodies, power and life in the communities he addressed.
Directory of Open Access Journals (Sweden)
P. G. Tillman
2012-01-01
Full Text Available The brown stink bug, Euschistus servus (Say, can disperse from source habitats, including corn, Zea mays L., and peanut, Arachis hypogaea L., into cotton, Gossypium hirsutum L. Therefore, a 2-year on-farm experiment was conducted to determine the effectiveness of a sorghum (Sorghum bicolor (L. Moench spp. bicolor trap crop, with or without Euschistus spp. pheromone traps, to suppress dispersal of this pest to cotton. In 2004, density of E. servus was lower in cotton fields with sorghum trap crops (with or without pheromone traps compared to control cotton fields. Similarly, in 2006, density of E. servus was lower in cotton fields with sorghum trap crops and pheromone traps compared to control cotton fields. Thus, the combination of the sorghum trap crop and pheromone traps effectively suppressed dispersal of E. servus into cotton. Inclusion of pheromone traps with trap crops potentially offers additional benefits, including: (1 reducing the density of E. servus adults in a trap crop, especially females, to possibly decrease the local population over time and reduce the overwintering population, (2 reducing dispersal of E. servus adults from the trap crop into cotton, and (3 potentially attracting more dispersing E. servus adults into a trap crop during a period of time when preferred food is not prevalent in the landscape.
Angular trap for macroparticles
International Nuclear Information System (INIS)
Aksyonov, D.S.
2013-01-01
Properties of angular macroparticle traps were investigated in this work. These properties are required to design vacuum arc plasma filters. The correlation between trap geometry parameters and its ability to absorb macroparticles were found. Calculations allow one to predict the behaviour of filtering abilities of separators which contain such traps in their design. Recommendations regarding the use of angular traps in filters of different builds are given.
Energy Technology Data Exchange (ETDEWEB)
Butler, E., E-mail: eoin.butler@cern.ch [CERN, Physics Department (Switzerland); Andresen, G. B. [Aarhus University, Department of Physics and Astronomy (Denmark); Ashkezari, M. D. [Simon Fraser University, Department of Physics (Canada); Baquero-Ruiz, M. [University of California, Department of Physics (United States); Bertsche, W. [Swansea University, Department of Physics (United Kingdom); Bowe, P. D. [Aarhus University, Department of Physics and Astronomy (Denmark); Cesar, C. L. [Universidade Federal do Rio de Janeiro, Instituto de Fisica (Brazil); Chapman, S. [University of California, Department of Physics (United States); Charlton, M.; Deller, A.; Eriksson, S. [Swansea University, Department of Physics (United Kingdom); Fajans, J. [University of California, Department of Physics (United States); Friesen, T.; Fujiwara, M. C. [University of Calgary, Department of Physics and Astronomy (Canada); Gill, D. R. [TRIUMF (Canada); Gutierrez, A. [University of British Columbia, Department of Physics and Astronomy (Canada); Hangst, J. S. [Aarhus University, Department of Physics and Astronomy (Denmark); Hardy, W. N. [University of British Columbia, Department of Physics and Astronomy (Canada); Hayden, M. E. [Simon Fraser University, Department of Physics (Canada); Humphries, A. J. [Swansea University, Department of Physics (United Kingdom); Collaboration: ALPHA Collaboration; and others
2012-12-15
Precision spectroscopic comparison of hydrogen and antihydrogen holds the promise of a sensitive test of the Charge-Parity-Time theorem and matter-antimatter equivalence. The clearest path towards realising this goal is to hold a sample of antihydrogen in an atomic trap for interrogation by electromagnetic radiation. Achieving this poses a huge experimental challenge, as state-of-the-art magnetic-minimum atom traps have well depths of only {approx}1 T ({approx}0.5 K for ground state antihydrogen atoms). The atoms annihilate on contact with matter and must be 'born' inside the magnetic trap with low kinetic energies. At the ALPHA experiment, antihydrogen atoms are produced from antiprotons and positrons stored in the form of non-neutral plasmas, where the typical electrostatic potential energy per particle is on the order of electronvolts, more than 10{sup 4} times the maximum trappable kinetic energy. In November 2010, ALPHA published the observation of 38 antiproton annihilations due to antihydrogen atoms that had been trapped for at least 172 ms and then released-the first instance of a purely antimatter atomic system confined for any length of time (Andresen et al., Nature 468:673, 2010). We present a description of the main components of the ALPHA traps and detectors that were key to realising this result. We discuss how the antihydrogen atoms were identified and how they were discriminated from the background processes. Since the results published in Andresen et al. (Nature 468:673, 2010), refinements in the antihydrogen production technique have allowed many more antihydrogen atoms to be trapped, and held for much longer times. We have identified antihydrogen atoms that have been trapped for at least 1,000 s in the apparatus (Andresen et al., Nature Physics 7:558, 2011). This is more than sufficient time to interrogate the atoms spectroscopically, as well as to ensure that they have relaxed to their ground state.
Daamid poolpöördes : Paul Raua naisportreede taustast / Tiina Abel
Abel, Tiina
2008-01-01
Vendade Raudade loomingust sajandivahetusel ja nende erinevatest inspiratsiooniallikatest. Ka muutustest ühiskondlikus elus ja kultuuriteadvuses - pöördumine ühiskondlikult isiklikule ja psühholoogilisele, tegelikkuse ja indiviidi teadvuse ümbermõtestamine, ratsionaalse inimese asendumine tunnete ja instiktide inimesega - see ilmneb Paul Raua psühholoogilistes hingestatud naiseportreedes
The neutron Electric Dipole Moment experiment at the Paul Scherrer Institute
Directory of Open Access Journals (Sweden)
Hélaine V.
2014-06-01
Full Text Available The neutron Electric Dipole Moment (nEDM is a probe for physics beyond the Standard Model. A report on the nEDM measurement performed at the Paul Scherrer Institute (Switzerland is given. A neutron spin analyzer designed to simultaneously detect both neutron spin states is presented.
Goldschmidt, Janice
2017-07-01
During the progression of a pilot nutrition intervention designed to teach cooking skills to young adults with autism spectrum disorder (ASD), one participant-Paul-fell in the parking lot. Prior to the accident, Paul had been making significant gains in the program and had communicated in a number of ways his enthusiasm. After his accident, which resulted in broken and dislocated bones in his ankle, his demeanor was dramatically altered, program gains were lost, and staff noted the appearance of many new challenging behaviors. This article analyzes Paul's behavior in reference to the pain response in autism. For some time, it was believed that many individuals with ASD did not experience pain based on anecdotal reports of how individuals responded to injury with seeming indifference. This view has given way of late to a more nuanced understanding of how atypical sensory processing and stimulus over-selectivity spill over into pain pathways and pain amplification mechanisms. The consequence is not a reduction in pain sensation, but a different expression of pain, determined by that individual's particular communicative, cognitive, or physiological challenges. From this perspective, many of the disruptive and harmful behaviors that emerged after Paul's accident can be seen as a delayed response to the incident. This article concludes by arguing that professionals across all domains of health care need to begin to see behavior as communicative for those with ASD. This is particularly true of changes in behavior, which can be significant indicators of health care problems rather than something to be dismissed as another manifestation of the condition.
Paul Collier : Balancing beams
2009-01-01
As former head of AB Operations, Paul Collier and his group were in the ‘cockpit’ for the LHC’s maiden voyage - piloting the first beam around the ring. But now, as Head of the Beams Department, he will need his feet firmly on the ground in order to balance all the beam activities at CERN. "As Department Head, I’ll have less direct contact with the machines," Collier says with a hint of regret. "I’ll still obviously be very involved, but they won’t actually let me loose in front of the keyboard anymore!" As the new Head of the BE Department, Collier will be in charge of nearly 400 people, and will oversee all the beam activities, including the preparations for the longest period of beam operation in the history of CERN. In the new organization, the BE, TE and EN Departments have been grouped together in the Accelerator and Technology Sector. "‘Partnership’ is a key word for the three departments," says Collier. "The n...
Francese, Joseph A; Rietz, Michael L; Mastro, Victor C
2013-12-01
Field assays were conducted in southeastern and south-central Michigan in 2011 and 2012 to optimize green and purple multifunnel (Lindgren funnel) traps for use as a survey tool for the emerald ash borer, Agrilus planipennis Fairmaire. Larger sized (12- and 16-unit) multifunnel traps caught more beetles than their smaller-sized (4- and 8-unit) counterparts. Green traps coated with untinted (white) fluon caught almost four times as many adult A. planipennis as Rain-X and tinted (green) fluon-coated traps and almost 33 times more beetles than untreated control traps. Purple multifunnel traps generally caught much lower numbers of A. planipennis adults than green traps, and trap catch on them was not affected by differences in the type of coating applied. However, trap coating was necessary as untreated control purple traps caught significantly less beetles than traps treated with Rain-X and untinted or tinted (purple) fluon. Proportions of male beetles captured were generally much higher on green traps than on purple traps, but sex ratios were not affected by trap coating. In 2012, a new shade of purple plastic, based on a better color match to an attractive purple paint than the previously used purple, was used for trapping assays. When multifunnel traps were treated with fluon, green traps caught more A. planipennis adults than both shades of purple and a prism trap that was manufactured based on the same color match. Trap catch was not affected by diluting the fluon concentration applied to traps to 50% (1:1 mixture in water). At 10%, trap catch was significantly lowered.
Energy Technology Data Exchange (ETDEWEB)
Margen, P.; Larsson, K.; Cronholm, L.A.; Marklund, J.E.
1979-08-01
A study was undertaken to determine the feasibility of introducing a large-scale, hot-water, district-heating system for the Minneapolis-St. Paul area. The analysis was based on modern European hot-water district-heating concepts in which cogeneration power plants supply the base-load thermal energy. Heat would be supplied from converted turbines of existing coal-fired power plants in Minneapolis and St. Paul. Toward the end of the 20-year development period, one or two new cogeneration units would be required. Thus, the district-heating system could use low-grade heat from either coal-fired or nuclear cogeneration power stations to replace the space-heating fuels currently used - natural gas and distillate oil. The following conclusions can be drawn: the concept is technically feasible, it has great value for fuel conservation, and with appropriate financing the system is economically viable.
Boundaries - US Army Corps of Engineers - St. Paul District (MVP) Civil Works
Army Corps of Engineers, Department of the Army, Department of Defense — The US Army Corps of Engineers - St. Paul District Civil Works boundary. Boundary is based on 1:24k watershed data and coordination with MVR to determine shared...
Resurrecting Democracies : Secularity Recast in Charles Taylor, Paul Valadier, and Joseph Ratzinger
Ossewaarde-Lowtoo, Roshnee
In this article, the alternative conception of secularity of Charles Taylor, Paul Valadier and Joseph Ratzinger (former Benedict XVI) is explored. A secularized society, which they take as an established condition, does not necessarily exclude religion, Christianity or Christian transcendence, in
Energy Technology Data Exchange (ETDEWEB)
Streubel, Sebastian; Eronen, Tommi; Hoecker, Martin; Ketter, Jochen; Blaum, Klaus [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Van Dyck, Robert S. Jr. [Department of Physics, University of Washington, Seattle, WA (United States)
2013-07-01
THe-Trap (short for Tritium-{sup 3}He Trap) is a Penning-trap setup dedicated to measure the {sup 3}H to {sup 3}He mass-ratio with a relative uncertainty of better than 10{sup -11}. The ratio is of relevance for the KArlsruhe TRItium Neutrino experiment (KATRIN), which aims to measure the electron anti-neutrino mass, by measuring the shape of the β-decay energy spectrum close to its endpoint. An independent measurement of the {sup 3}H to {sup 3}He mass-ratio pins down this endpoint, and thus will help to determine the systematics of KATRIN. The trap setup consists of two Penning-traps: One trap for precision measurements, the other trap for ion storage. Ideally, the trap content will be periodically switched, which reduces the time between the measurements of the two ions' motional frequencies. In 2012, a mass ratio measurement of {sup 12}C{sup 4+} to {sup 14}N{sup 5+} was performed to characterize systematic effects of the traps. This measurement yielded a accuracy of 10{sup -9}. Further investigations revealed that a major reason for the modest accuracy is the large axial amplitude of ∼100 μm, compared to a ideal case of 3 μm at 4 K. In addition, relative magnetic fluctuations at a 3 x 10{sup -10} level on a 10 h timescale need to be significantly improved. In this contribution, the aforementioned findings and further systematic studies will be presented.
Fast Transverse Beam Instability Caused by Electron Cloud Trapped in Combined Function Magnets
Energy Technology Data Exchange (ETDEWEB)
Antipov, Sergey [Univ. of Chicago, IL (United States)
2017-03-01
Electron cloud instabilities affect the performance of many circular high-intensity particle accelerators. They usually have a fast growth rate and might lead to an increase of the transverse emittance and beam loss. A peculiar example of such an instability is observed in the Fermilab Recycler proton storage ring. Although this instability might pose a challenge for future intensity upgrades, its nature had not been completely understood. The phenomena has been studied experimentally by comparing the dynamics of stable and unstable beam, numerically by simulating the build-up of the electron cloud and its interaction with the beam, and analytically by constructing a model of an electron cloud driven instability with the electrons trapped in combined function dipoles. Stabilization of the beam by a clearing bunch reveals that the instability is caused by the electron cloud, trapped in beam optics magnets. Measurements of microwave propagation confirm the presence of the cloud in the combined function dipoles. Numerical simulations show that up to 10$^{-2}$ of the particles can be trapped by their magnetic field. Since the process of electron cloud build-up is exponential, once trapped this amount of electrons significantly increases the density of the cloud on the next revolution. In a combined function dipole this multi-turn accumulation allows the electron cloud reaching final intensities orders of magnitude greater than in a pure dipole. The estimated fast instability growth rate of about 30 revolutions and low mode frequency of 0.4 MHz are consistent with experimental observations and agree with the simulations. The created instability model allows investigating the beam stability for the future intensity upgrades.
Directory of Open Access Journals (Sweden)
Emile Bernard
2009-01-01
Full Text Available Bernard afirma (no final de seu texto ter escrito este artigo em Aix em março de 1904. Na realidade este deve ter tomado sua forma definitiva mais tarde, pois contém importantes citações tiradas das cartas de Cézanne datadas de 12 e 26 de maio. Embora seja conhecido pelos especialistas, este artigo (p. 17 a 30 no número de julho de 1904 do Occident foi algo eclipsado, nos estudos sobre Cézanne, pelos dois textos do Mercure de France que compõem os Souvenirs sur Paul Cézanne... e suas diversas reedições em forma de livro. O artigo do Occident é, em grande medida, consagrado às visões gerais de Bernard sobre a arte, mas, além da famosa compilação das opiniões de Cézanne, oferece citações aparentemente textuais do artista e algumas observações às vezes profundas sobre seus métodos de trabalho e sua evolução como pintor. Os comentários sobre Pissarro e o período de Auvers parecem exatos. Quanto à autenticidade das "opiniões", devemos ter em mente, por um lado, que Bernard se preocupa em assinalar, várias vezes, neste artigo, as ocasiões em que cita as próprias palavras de Cézanne e, por outro lado, que as "opiniões" propriamente ditas são enriquecidas com trechos de cartas, o que permite supor que a seção inteira seria composta de citações autênticas. P. M. DoranBernard claims (in the end of his text to have written this article in Aix in March 1904. Actually, it must have taken its final version later, since it contains important quotes drawn from Cézanne's letters of May 12 and 26. This article (pages 17 to 30 of the issue of July 1904 of Occident, although known among scholars, was somehow eclipsed, in the studies about Cézanne, by the two texts from Mercure de France which constitute the Souvenirs sur Paul Cézanne... and its various re-editions as a book. The article in Occident is mostly dedicated to Bernard's general views on art, but it offers, beyond the famous compilation of Cézanne's opinions
Dokumentaalselt tõestatud: Paul Keresel suleti tee maailmameistri tiitlile / Paavo Kivine
Kivine, Paavo, 1939-
2015-01-01
Miks neli aastakümmet tipus püsinud suurmeister ei tulnud maailmameistriks. Lisatud dokument on pöördumine Venemaa Kommunistliku Partei II sekretäri ülesandeid täitnud Andrei Ždanovi poole ettepanekuga lubada Paul Keresel osaleda 1947. aasta maailmameistrivõistlustel (foto venekeelsest dokumendist ja tõlge)
Sharp Trapping Boundaries in the Random Walk of Interplanetary Magnetic Field Lines
Ruffolo, D.; Chuychai, P.; Meechai, J.; Pongkitiwanichkul, P.; Kimpraphan, N.; Matthaeus, W. H.; Rowlands, G.
2004-05-01
Although magnetic field lines in space are believed to undergo a diffusive random walk in the long-distance limit, observed dropouts of solar energetic particles, as well as computer simulations, indicate sharply defined filaments in which interplanetary magnetic field lines have been temporarily trapped. We identify mechanisms that can explain such sharp boundaries in the framework of 2D+slab turbulence, a model that provides a good explanation of solar wind turbulence spectra and the parallel transport of solar energetic particles. Local trapping boundaries (LTBs) are empirically defined as trajectories of 2D turbulence where the mean 2D field is a local maximum. In computer simulations, the filaments (or ``islands'' in the two dimensions perpendicular to the mean field) that are most resistant to slab diffusion correspond closely to the mathematically defined LTBs, that is, there is a mathematical prescription for defining the trapping regions. Furthermore, we provide computational evidence and a theoretical explanation that strong 2D turbulence can inhibit diffusion due to the slab component. Therefore, while these filaments are basically defined by the small-scale topology of 2D turbulence, there can be sharp trapping boundaries where the 2D field is strongest. This work was supported by the Thailand Research Fund, the Rachadapisek Sompoj Fund of Chulalongkorn University, and NASA Grant NAG5-11603. G.R. thanks Mahidol University for its hospitality and the Thailand Commission for Higher Education for travel support.
Optical trapping of gold aerosols
DEFF Research Database (Denmark)
Schmitt, Regina K.; Pedersen, Liselotte Jauffred; Taheri, S. M.
2015-01-01
Aerosol trapping has proven challenging and was only recently demonstrated.1 This was accomplished by utilizing an air chamber designed to have a minimum of turbulence and a laser beam with a minimum of aberration. Individual gold nano-particles with diameters between 80 nm and 200 nm were trapped...... in air using a 1064 nm laser. The positions visited by the trapped gold nano-particle were quantified using a quadrant photo diode placed in the back focal plane. The time traces were analyzed and the trapping stiffness characterizing gold aerosol trapping determined and compared to aerosol trapping...... of nanometer sized silica and polystyrene particles. Based on our analysis, we concluded that gold nano-particles trap more strongly in air than similarly sized polystyrene and silica particles. We found that, in a certain power range, the trapping strength of polystyrene particles is linearly decreasing...
Trapped modes in a dummy extraction septum for CERN Proton Synchrotron
International Nuclear Information System (INIS)
Persichelli, S.
2014-01-01
The term trapped mode is usually referred to a mode that can not propagate in the beam pipe, but is localized in a particular region inside the device, producing narrow resonances peaks in the coupling impedance. They can be excited by the presence of discontinuities inside different devices of an accelerator, producing unwanted beam instabilities. It is therefore important to identify trapped modes, especially for new elements to be installed in a high-intensity accelerator. We present a recent study of the coupling impedance due to trapped modes in a new extraction septum that will be installed in the CERN Proton Synchrotron in the framework of PS Multi-turn extraction (MTE) commissioning. Simulation and theoretical calculations were performed in order to understand performance limitations of the machine, to find cures to reduce the instabilities, and to evaluate beam-induced heating.
Gas-partitioning tracer test to qualify trapped gas during recharge
Heilweil, Victor M.; Kip, Solomon D.; Perkins, Kim S.; Ellett, Kevin M.
2004-01-01
Dissolved helium and bromide tracers were used to evaluate trapped gas during an infiltration pond experiment. Dissolved helium preferentially partitioned into trapped gas bubbles, or other pore air, because of its low solubility in water. This produced observed helium retardation factors of as much as 12 relative to bromide. Numerical simulations of helium breakthrough with both equilibrium and kinetically limited advection/dispersion/retardation did not match observed helium concentrations. However, better fits were obtained by including a decay term representing the diffusive loss of helium through interconnected, gas-filled pores. Calculations indicate that 7% to more than 26% of the porosity beneath the pond was filled with gas. Measurements of laboratory hydraulic properties indicate that a 10% decrease in saturation would reduce the hydraulic conductivity by at least one order of magnitude in the well-sorted sandstone, but less in the overlying soils. This is consistent with in situ measurements during the experiment, which show steeper hydraulic gradients in sandstone than in soil. Intrinsic permeability of the soil doubled during the first six months of the experiment, likely caused by a combination of dissolution and thermal contraction of trapped gas. Managers of artificial recharge basins may consider minimizing the amount of trapped gas by using wet, rather than dry, tilling to optimize infiltration rates, particularly in well-sorted porous media in which reintroduced trapped gas may cause substantial reductions in permeability. Trapped gas may also inhibit the amount of focused infiltration that occurs naturally during ephemeral flood events along washes and playas.
Gas-partitioning tracer test to quantify trapped gas during recharge
Heilweil, V.M.; Solomon, D.K.; Perkins, K.S.; Ellett, K.M.
2004-01-01
Dissolved helium and bromide tracers were used to evaluate trapped gas during an infiltration pond experiment. Dissolved helium preferentially partitioned into trapped gas bubbles, or other pore air, because of its low solubility in water. This produced observed helium retardation factors of as much as 12 relative to bromide. Numerical simulations of helium breakthrough with both equilibrium and kinetically limited advection/dispersion/retardation did not match observed helium concentrations. However, better fits were obtained by including a decay term representing the diffusive loss of helium through interconnected, gas-filled pores. Calculations indicate that 7% to more than 26% of the porosity beneath the pond was filled with gas. Measurements of laboratory hydraulic properties indicate that a 10% decrease in saturation would reduce the hydraulic conductivity by at least one order of magnitude in the well-sorted sandstone, but less in the overlying soils. This is consistent with in situ measurements during the experiment, which show steeper hydraulic gradients in sandstone than in soil. Intrinsic permeability of the soil doubled during the first six months of the experiment, likely caused by a combination of dissolution and thermal contraction of trapped gas. Managers of artificial recharge basins may consider minimizing the amount of trapped gas by using wet, rather than dry, tilling to optimize infiltration rates, particularly in well-sorted porous media in which reintroduced trapped gas may cause substantial reductions in permeability. Trapped gas may also inhibit the amount of focused infiltration that occurs naturally during ephemeral flood events along washes and playas.
Status of the LPCTrap facility at GANIL
International Nuclear Information System (INIS)
Duval, F.; Mery, A.; Ban, G.; Durand, D.; Flechard, X.; Labalme, M.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Rodriguez-Rubiales, D.; Thomas, J.C.
2008-01-01
The LPCTrap is a device whose central element is a transparent Paul trap for the efficient trapping of low energy radioactive ions produced by the SPIRAL facility at GANIL. The installation comprises a linear RFQ cooler and buncher for the beam preparation, and a decay chamber where the Paul trap is located. The system has been tested with ions having mass-to-charge ratios ranging from 4 to 40. The first run with radioactive 6 He + ions has demonstrated the overall performance of the system. In this contribution we describe the current status of the device, we present in particular the results of a numerical study carried out to determine the properties of the ion cloud inside the trap and provide updated values for the overall efficiency of the system.
Secondary scattering on the intensity dependence of the capture velocity in a magneto-optical trap
International Nuclear Information System (INIS)
Loos, M.R.; Massardo, S.B.; Zanon, R.A. de S; Oliveira, A.L. de
2005-01-01
In this work, we consider a three-dimensional model to simulate the capture velocity behavior in a sample of cold-trapped sodium atoms as a function of the trapping laser intensity. We expand on previous work [V. S. Bagnato, L. G. Marcassa, S. G. Miranda, S. R. Muniz, and A. L. de Oliveira, Phys. Rev. A 62, 013404 (2000)] by calculating the capture velocity over a broad range of light intensities considering the secondary scattering in a magneto-optical trap. Our calculations are in a good agreement with recent measured values [S. R. Muniz et al., Phys. Rev. A 65, 015402 (2001)
Secondary scattering on the intensity dependence of the capture velocity in a magneto-optical trap
Loos, M. R.; Massardo, S. B.; de S. Zanon, R. A.; de Oliveira, A. L.
2005-08-01
In this work, we consider a three-dimensional model to simulate the capture velocity behavior in a sample of cold-trapped sodium atoms as a function of the trapping laser intensity. We expand on previous work [V. S. Bagnato, L. G. Marcassa, S. G. Miranda, S. R. Muniz, and A. L. de Oliveira, Phys. Rev. A 62, 013404 (2000)] by calculating the capture velocity over a broad range of light intensities considering the secondary scattering in a magneto-optical trap. Our calculations are in a good agreement with recent measured values [S. R. Muniz , Phys. Rev. A 65, 015402 (2001)].
Der andere Kisch: der Literaturhistoriker und –kritiker Paul Kisch (1883–1944)
Czech Academy of Sciences Publication Activity Database
Petrbok, Václav
2015-01-01
Roč. 23, 1-2 (2015), s. 79-100 ISSN 1803-456X Institutional support: RVO:68378068 Keywords : Kisch, Paul * literary criticism * Czech-German relationships * intercultural studies Subject RIV: AJ - Letters, Mass-media, Audiovision
Peter Paul Rubens, Galileo Galilei und die Schlacht am Weißen Berg
Czech Academy of Sciences Publication Activity Database
Konečný, Lubomír
2005-01-01
Roč. 26, č. 52 (2005), s. 85-91 ISSN 0391-9064 Institutional research plan: CEZ:AV0Z80330511 Keywords : Peter Paul Rubens * Galileo Galilei * moon Subject RIV: AL - Art, Architecture, Cultural Heritage
International Nuclear Information System (INIS)
Zhu, Zhaohuan; Stone, James M.
2014-01-01
We study particle trapping at the edge of a gap opened by a planet in a protoplanetary disk. In particular, we explore the effects of turbulence driven by the magnetorotational instability on particle trapping, using global three-dimensional magnetohydrodynamic (MHD) simulations including Lagrangian dust particles. We study disks either in the ideal MHD limit or dominated by ambipolar diffusion (AD) which plays an essential role at the outer regions of a protoplanetary disk. With ideal MHD, strong turbulence (the equivalent viscosity parameter α ∼ 10 –2 ) in disks prevents vortex formation at the edge of the gap opened by a 9 M J planet, and most particles (except the particles that drift fastest) pile up at the outer gap edge almost axisymmetrically. When AD is considered, turbulence is significantly suppressed (α ≲ 10 –3 ), and a large vortex forms at the edge of the planet induced gap, which survives ∼1000 orbits. The vortex can efficiently trap dust particles that span 3 orders of magnitude in size within 100 planetary orbits. We have also carried out two-dimensional hydrodynamical (HD) simulations using viscosity as an approximation to MHD turbulence. These HD simulations can reproduce vortex generation at the gap edge as seen in MHD simulations. Finally, we use our simulation results to generate synthetic images for ALMA dust continuum observations on Oph IRS 48 and HD 142527, which show good agreement with existing observations. Predictions for future ALMA cycle 2 observations have been made. We conclude that the asymmetry in ALMA observations can be explained by dust trapping vortices and the existence of vortices could be the evidence that the outer protoplanetary disks are dominated by AD with α < 10 –3 at the disk midplane.
Experimental system design for the integration of trapped-ion and superconducting qubit systems
De Motte, D.; Grounds, A. R.; Rehák, M.; Rodriguez Blanco, A.; Lekitsch, B.; Giri, G. S.; Neilinger, P.; Oelsner, G.; Il'ichev, E.; Grajcar, M.; Hensinger, W. K.
2016-12-01
We present a design for the experimental integration of ion trapping and superconducting qubit systems as a step towards the realization of a quantum hybrid system. The scheme addresses two key difficulties in realizing such a system: a combined microfabricated ion trap and superconducting qubit architecture, and the experimental infrastructure to facilitate both technologies. Developing upon work by Kielpinski et al. (Phys Rev Lett 108(13):130504, 2012. doi: 10.1103/PhysRevLett.108.130504), we describe the design, simulation and fabrication process for a microfabricated ion trap capable of coupling an ion to a superconducting microwave LC circuit with a coupling strength in the tens of kHz. We also describe existing difficulties in combining the experimental infrastructure of an ion trapping set-up into a dilution refrigerator with superconducting qubits and present solutions that can be immediately implemented using current technology.
Simulations and experiments on RITA-2 at PSI
International Nuclear Information System (INIS)
Klausen, S.N.; Lefmann, K.; McMorrow, D.F.; Altorfer, F.; Janssen, S.; Luethy, M.
2002-01-01
The cold-neutron triple-axis spectrometer RITA-2 designed and built at Riso National Laboratory was installed at the neutron source SINQ at Paul Scherrer Institute in April/May 2001. In connection with the installation of RITA-2, computer simulations were performed using the neutron ray-tracing package McStas. The simulation results are compared to real experimental results obtained with a powder sample. Especially, the flux at the sample position and the resolution function of the spectrometer are investigated. (orig.)
Simulations and experiments on RITA-2 at PSI
Klausen, S. N.; Lefmann, K.; McMorrow, D. F.; Altorfer, F.; Janssen, S.; Lüthy, M.
The cold-neutron triple-axis spectrometer RITA-2 designed and built at Riso National Laboratory was installed at the neutron source SINQ at Paul Scherrer Institute in April/May 2001. In connection with the installation of RITA-2, computer simulations were performed using the neutron ray-tracing package McStas. The simulation results are compared to real experimental results obtained with a powder sample. Especially, the flux at the sample position and the resolution function of the spectrometer are investigated.
The history and epidemiology of Cape St Paul wilt disease of ...
African Journals Online (AJOL)
The history of the spread of the Cape St. Paul Wilt (lethal yellowing) disease of coconut in Ghana is presented. Epidemiological studies showed that the disease starts slowly, then progresses (accelerate) rapidly before levelling off. In a farm, the disease first appears randomly on single trees, foci then develop around these ...
O avesso do visível: poética de Paul Klee
Directory of Open Access Journals (Sweden)
Maria Beatriz da Rocha Lagôa
2006-01-01
Full Text Available O artista Paul Klee investiga os processos da forma, conjugando materiais e técnicas que tecem suas próprias relações. O que caracteriza sua obra é a compreensão da Modernidade, as correspondências com outras culturas e demais gêneros de expressão artística. O traço, não mediado pela referência à natureza, atua como instrumento de busca de uma forma mais livre, que se desdobra no tempo e no espaço, e exige a participação do espectador.El artista Paul Klee investiga los procesos de la forma, conjugando materiales y técnicas que tejem sus relaciones próprias. Lo que caracteriza su obra es la compreensión de la Modernidad, las correspondencias con otras culturas y otros géneros de expresión artística. El trazo, sin mediación por la referencia a la naturaleza, actua como instrumento de busca de una forma mas libre, que se desdobla en el tiempo y en el espacio, exigiendo la participación del espectador.Paul Klee investigates the process of form, conjugating materials and techniques that weave their own relations. The artist understands the Modernity, its correspondences with the other cultures and means of artistic expression. The line, non mediated by references to nature, acts as an instrument in the search for a freer form, unfolding through space and time, and demanding the participation of the viewer.
Paule Marshall and the search for the African diaspora
Directory of Open Access Journals (Sweden)
Simon Gikandi
1999-01-01
Full Text Available [First paragraph] The Fiction of Paule Marshall: Reconstructions of History, Culture, and Gender. DOROTHY HAMER DENNISTON. Knoxville: University of Tennesee Press, 1995. xxii + 187 pp. (Paper US$ 15.00 Toward Wholeness in Paule Marshall's Fiction. JOYCE PETTIS. Charlottesville: University of Virginia Press, 1995. xi + 173 pp. (Cloth US$ 29.50 Black and Female: Essays on Writings by Black Women in the Diaspora. BRITA LINDBERG-SEYERSTED. Oslo: Scandinavian University Press, 1994. 164 pp. (Paper n.p. Literary history has not been very kind to Paule Marshall. Even in the early 1980s when literature produced by African-American women was gaining prominence among general readers and drawing the attention of critics, Marshall was still considered to be an enigmatic literary figure, somehow important in the canon but not one of its trend setters. As Mary Helen Washington observed in an influential afterword to Brown Girl, Brownstones, although Marshall had been publishing novels and short stories since the early 1950s, and was indeed the key link between African-American writers of the 1940s and those of the 1960s, she was just being "discovered" in the 1980s. While there has always been a small group of scholars, most notably Kamau Brathwaite, who have called attention to the indispensable role Marshall has played in the shaping of the literary canon of the African Diaspora, and of her profound understanding of the issues that have affected the complex formation and survival of African-derived cultures in the New World, many critics have found it difficult to locate her within the American, African-American, and Caribbean traditions that are the sources of her imagination and the subject of her major works. Marshall has embraced all these cultures in more profound ways than her more famous contemporaries have, but she has not gotten the accolades that have gone to lesser writers like Alice Walker. It is indeed one of the greatest injustices of
Calculation of stationary plasma parameters in an electromagnetic trap
International Nuclear Information System (INIS)
Karpukhin, V.I.; Lavrent'ev, O.A.; Sappa, N.N.
1978-01-01
The model of energy and particle balance is considered and the numerical calculations for stationary plasma parameters, supported by the electron injection, are obtained for a hypothetical electromagnetic trap with linear dimensions, magnetic field strength and energy contribution to plasma of the order of these parameters for the modern tokamak-type traps. The process of limitation of an effective injection current and energy contribution to plasma caused by returning of electrons to the injector due to diffusion in the velocity space is simulated. In approximation of a classical diffusion dependences are obtained of the effective energy contribution to plasma and of the parameters ntausub(E) and Tsub(i) (n is a plasma density; tausub(E)- energetic lifetime; Tsub(i) ion temperature) on electron injection current and power and on the confining magnetic field strength. It had been established that at classical character of diffusion in electromagnetic trap with above parameters one could obtain stationary plasma with ntausub(E)=10 12 cm -3 s and Tsub(i)=1keV, maintaining only by electron injection
Search For Trapped Antihydrogen
Andresen, Gorm B.; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D.; Bray, Crystal C.; Butler, Eoin; Cesar, Claudio L.; Chapman, Steven; Charlton, Michael; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C.; Gill, David R.; Hangst, Jeffrey S.; Hardy, Walter N.; Hayano, Ryugo S.; Hayden, Michael E.; Humphries, Andrew J.; Hydomako, Richard; Jonsell, Svante; Jorgensen, Lars V.; Kurchaninov, Lenoid; Lambo, Ricardo; Madsen, Niels; Menary, Scott; Nolan, Paul; Olchanski, Konstantin; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Nasr, Sarah Seif El; Silveira, Daniel M.; So, Chukman; Storey, James W.; Thompson, Robert I.; van der Werf, Dirk P.; Wilding, Dean; Wurtele, Jonathan S.; Yamazaki, Yasunori
2011-01-01
We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over ~30 ms. After a three-week experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9 positrons to produce 6 10^5 antihydrogen atoms, we have identified six antiproton annihilation events that are consist...
Estima, Camilla C P; Bruening, Meg; Hannan, Peter J; Alvarenga, Marle S; Leal, Greisse V S; Philippi, Sonia T; Neumark-Sztainer, Dianne
2014-01-01
Describe cross-cultural differences in nutrition-related factors among adolescents from São Paulo, Brazil and St Paul-Minneapolis, US. Two large-population-based studies with cross-cultural comparisons. Twelve São Paulo and 10 St Paul-Minneapolis high schools in 2009-2010. A total of 1,148 adolescents from São Paulo and 1,632 adolescents from St Paul-Minneapolis. Meal consumption, family meals, fast-food consumption, and home food availability. Binomial regressions, weighted for age distributions and adjusted for gender, were used to compare identical measures from each sample. Generally, São Paulo adolescents reported healthier nutritional outcomes than St Paul-Minneapolis adolescents. São Paulo adolescents were 7 times less likely to report high fast-food consumption than St Paul-Minneapolis adolescents (P culture. Interventions are needed to encourage youth and their families to maintain these patterns. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.
[Trapping techniques for Solenopsis invicta].
Liang, Xiao-song; Zhang, Qiang; Zhuang, Yiong-lin; Li, Gui-wen; Ji, Lin-peng; Wang, Jian-guo; Dai, Hua-guo
2007-06-01
A field study was made to investigate the trapping effects of different attractants, traps, and wind directions on Solenopsis invicta. The results showed that among the test attractants, TB1 (50 g fishmeal, 40 g peptone, 10 ml 10% sucrose water solution and 20 ml soybean oil) had the best effect, followed by TB2 (ham), TB6 (100 g cornmeal and 20 ml soybean oil) and TB4 (10 ml 10% sucrose water solution, 100 g sugarcane powder and 20 ml soybean oil), with a mean capture efficiency being 77.6, 58.7, 29 and 7.7 individuals per trap, respectively. No S. invicta was trapped with TB3 (10 ml 10% sucrose water solution, 100 g cornmeal and 20 ml soybean oil) and TB5 (honey). Tube trap was superior to dish trap, with a trapping efficiency of 75.2 and 35 individuals per trap, respectively. The attractants had better effects in leeward than in windward.
International Nuclear Information System (INIS)
Zupac, D.; Galloway, K.F.; Khosropour, P.; Anderson, S.R.; Schrimpf, R.D.
1993-01-01
An effective approach to separating the effects of oxide-trapped charge and interface-trapped charge on mobility degradation in irradiated MOSFETs is demonstrated. It is based on analyzing mobility data sets which have different functional relationships between the radiation-induced-oxide-trapped charge and interface-trapped charge. Separation of effects of oxide-trapped charge and interface-trapped charge is possible only if these two trapped charge components are not linearly dependent. A significant contribution of oxide-trapped charge to mobility degradation is demonstrated and quantified
Energy Technology Data Exchange (ETDEWEB)
Andreev, V. V., E-mail: temple18@mail.ru; Novitsky, A. A.; Vinnichenko, L. A.; Umnov, A. M.; Ndong, D. O. [Peoples’ Friendship University of Russia (Russian Federation)
2016-03-15
The parameters of the injector of an axial plasma beam injected into a plasma accelerator operating on the basis of gyroresonance acceleration of electrons in the reverse magnetic field are determined. The trapping of the beam electrons into the regime of gyroresonance acceleration is numerically simulated by the particle- in-cell method. The optimal time of axial injection of the beam into a magnetic mirror trap is determined. The beam parameters satisfying the condition of efficient particle trapping into the gyromagnetic autoresonance regime are found.
On social justice: Comparing Paul with Plato, Aristotle and the Stoics ...
African Journals Online (AJOL)
Although Crossan elsewhere demonstrates the deep roots of this concern in the Jewish tradition, he tends to downplay the importance of Greek contributions in this regard. The purpose of this essay will be to offer, in constant dialogue with. Crossan (and Reed), a more refined comparison of social justice in Paul on the one ...
Trapped-particle instabilities in quasi-isodynamic stellarators
Energy Technology Data Exchange (ETDEWEB)
Proll, Josefine Henriette Elise
2014-01-28
approximately in quasi-isodynamic stellarators, for example Wendelstein 7-X. In such configurations the precessional drift of the trapped particles is in the opposite direction from the direction of propagation of drift waves. Instabilities that are driven by the trapped particles usually rely on a resonance between these two frequencies. Here it is shown analytically by analysing the electrostatic energy transfer between the particles and the instability that, thanks to the absence of the resonance, a particle species draws energy from the mode if the frequency of the mode is well below the characteristic bounce frequency. Due to the low electron mass and the fast bounce motion, electrons are almost always found to be stabilising. Most of the trapped-particle instabilities are therefore predicted to be absent in maximum- J configurations in large parts of parameter space. Analytical theory thus predicts enhanced linear stability of trapped-particle modes in quasi-isodynamic stellarators compared with tokamaks. Moreover, since the electrons are expected to be stabilising, or at least less destabilising, for all instabilities whose frequency lies below the trapped-electron bounce frequency, other modes might benefit from the enhanced stability as well. In reality, however, stellarators are never perfectly quasi-isodynamic, and the question thus arises whether they still benefit from enhanced stability. Here the stability properties of Wendelstein 7-X and a more quasi-isodynamic configuration, QIPC, are investigated numerically and compared with another, non-quasiisodynamic stellarator, the National Compact Stellarator Experiment (NCSX) and a typical tokamak. In gyrokinetic simulations, performed with the gyrokinetic code GENE in the electrostatic and collisionless approximation, several microinstabilities, driven by the density as well as both ion and electron temperature gradients, are studied. Wendelstein 7-X and QIPC exhibit significantly reduced growth rates for all
Trapped-particle instabilities in quasi-isodynamic stellarators
International Nuclear Information System (INIS)
Proll, Josefine Henriette Elise
2014-01-01
approximately in quasi-isodynamic stellarators, for example Wendelstein 7-X. In such configurations the precessional drift of the trapped particles is in the opposite direction from the direction of propagation of drift waves. Instabilities that are driven by the trapped particles usually rely on a resonance between these two frequencies. Here it is shown analytically by analysing the electrostatic energy transfer between the particles and the instability that, thanks to the absence of the resonance, a particle species draws energy from the mode if the frequency of the mode is well below the characteristic bounce frequency. Due to the low electron mass and the fast bounce motion, electrons are almost always found to be stabilising. Most of the trapped-particle instabilities are therefore predicted to be absent in maximum- J configurations in large parts of parameter space. Analytical theory thus predicts enhanced linear stability of trapped-particle modes in quasi-isodynamic stellarators compared with tokamaks. Moreover, since the electrons are expected to be stabilising, or at least less destabilising, for all instabilities whose frequency lies below the trapped-electron bounce frequency, other modes might benefit from the enhanced stability as well. In reality, however, stellarators are never perfectly quasi-isodynamic, and the question thus arises whether they still benefit from enhanced stability. Here the stability properties of Wendelstein 7-X and a more quasi-isodynamic configuration, QIPC, are investigated numerically and compared with another, non-quasiisodynamic stellarator, the National Compact Stellarator Experiment (NCSX) and a typical tokamak. In gyrokinetic simulations, performed with the gyrokinetic code GENE in the electrostatic and collisionless approximation, several microinstabilities, driven by the density as well as both ion and electron temperature gradients, are studied. Wendelstein 7-X and QIPC exhibit significantly reduced growth rates for all
Research at the Paul Scherrer Institut
International Nuclear Information System (INIS)
Walter, H.K.
1996-01-01
The Paul Scherrer Institut (PSI) is a multidisciplinary research institute for natural sciences and technology. In national and international collaboration with universities, other research institutes and industry, PSI is active in elementary particle physics, life sciences, solid-state physics, material sciences, nuclear and non-nuclear energy research, and energy-related ecology. PSI's priorities lie in research fields which are relevant to sustainable development, serve educational needs and are beyond the possibilities of a single university department. PSI develops and operates complex research installations open of the world's most powerful cyclotron, allowing to operate high intensity secondary pion and muon beams, a neutron spallation source and various applications in medicine and materials research. A short review on research at PSI is presented, with special concentration on particle physics experiments. (author)
Directory of Open Access Journals (Sweden)
Keanchuan Lee
2012-06-01
Full Text Available A silver nanoparticles self-assembled monolayer (SAM was incorporated in pentacene field-effect transistor and its effects on the carrier injection and transport were investigated using the current-voltage (I − V and impedance spectroscopy (IS measurements. The I − V results showed that there was a significant negative shift of the threshold voltage, indicating the hole trapping inside the devices with about two orders higher in the contact resistance and an order lower in the effective mobility when a SAM was introduced. The IS measurements with the simulation using a Maxwell-Wagner equivalent circuit model revealed the existence of multiple trapping states for the devices with NPs, while the devices without NPs exhibited only a single trap state.
Literature in focus: Paul Ginsparg
2008-01-01
Paul Ginsparg, professor of physics, computing and information science at Cornell University, is best known as the creator of an online system for distributing scientific research results. Known by scientists around the world as "arXiv.org", the system was designed to distribute electronic copies of the preprints that until 17 years ago were all distributed on paper and shipped in their thousands by the postal services. Ginsparg, at the time based at Los Alamos, carried out this work in his spare time using surplus equipment! It is amusing to look backwards and observe how this new technology was perceived in the beginning: In early 1994 Ginsparg happened to serve on a committee advising the American Physical Society (APS) about putting Physical Review Letters online. He suggested that a Web interface along the lines of the xxx.lanl.gov prototype might be a good way for the APS to disseminate its documents. A response came back from another committee member: "Installing and learni...
Electron traps in semiconducting polymers : Exponential versus Gaussian trap distribution
Nicolai, H. T.; Mandoc, M. M.; Blom, P. W. M.
2011-01-01
The low electron currents in poly(dialkoxy-p-phenylene vinylene) (PPV) derivatives and their steep voltage dependence are generally explained by trap-limited conduction in the presence of an exponential trap distribution. Here we demonstrate that the electron transport of several PPV derivatives can
Electron traps in semiconducting polymers: exponential versus Gaussian trap distribution
Nicolai, H.T.; Mandoc, M.M.; Blom, P.W.M.
2011-01-01
The low electron currents in poly(dialkoxy-p-phenylene vinylene) (PPV) derivatives and their steep voltage dependence are generally explained by trap-limited conduction in the presence of an exponential trap distribution. Here we demonstrate that the electron transport of several PPV derivatives can