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Sample records for cold trapped ions

  1. Quantum simulations with cold trapped ions

    NASA Astrophysics Data System (ADS)

    Blatt, Rainer

    2016-05-01

    The quantum toolbox of the Innsbruck ion-trap quantum computer is applied to simulate the dynamics and to investigate the propagation of entanglement in a quantum many-body system represented by long chains of trapped-ion qubits. Quantum dynamics can be described by particle-like carriers of information that emerge in the collective behavior of the underlying system, the so-called quasiparticles. These elementary excitations are predicted to distribute quantum information in a fashion determined by the system's interactions. First, we observe the entanglement distributed by quasiparticles as they trace out light-cone-like wavefronts. Second, using the ability to tune the interaction range in our system, we observe information propagation in an experimental regime where the effective-lightcone picture does not apply. Moreover, a spectroscopic technique is presented to study artificial quantum matter and use it for characterizing quasiparticles in a many-body system of trapped atomic ions. Our approach is to excite combinations of the system's fundamental quasiparticle eigenmodes, given by delocalized spin waves. By observing the dynamical response to superpositions of such eigenmodes, we extract the system dispersion relation, magnetic order, and even detect signatures of quasiparticle interactions. In the second part of the talk, it will be shown how strings of trapped ions can be used for quantum simulations of a lattice gauge field theory. As an example, we map the real-time evolution of the Schwinger mechanism to a string of trapped ions in a few-qubit quantum computer, simulating the spontaneous creation of electron-positron pairs.

  2. Vibrational Spectroscopy on Trapped Cold Molecular Ions

    NASA Astrophysics Data System (ADS)

    Khanyile, Ncamiso B.; Brown, Kenneth R.

    2014-06-01

    We perform vibrational spectroscopy on the V0←10 overtone of a trapped and sympathetically cooled CaH+ molecular ion using a resonance enhanced two photon dissociation scheme. Our experiments are motivated by theoretical work that proposes comparing the vibrational overtones of CaH^+ with electronic transitions in atoms to detect possible time variation of in the mass ratio of the proton to electron. Due to the nonexistence of experimental data of the transition, we start the search with a broadband femtosecond Ti:Saph laser guided by theoretical calculations. Once the vibrational transition has been identified, we will move to CW lasers to perform rotationally resolved spectroscopy. M. Kajita and Y. Moriwaki, J. Phys. B. At. Mol. Opt.Phys., 42,154022(2009) Private communication

  3. Precision Spectroscopy on Single Cold Trapped Molecular Nitrogen Ions

    NASA Astrophysics Data System (ADS)

    Hegi, Gregor; Najafian, Kaveh; Germann, Matthias; Sergachev, Ilia; Willitsch, Stefan

    2016-06-01

    The ability to precisely control and manipulate single cold trapped particles has enabled spectroscopic studies on narrow transitions of ions at unprecedented levels of precision. This has opened up a wide range of applications, from tests of fundamental physical concepts, e.g., possible time-variations of fundamental constants, to new and improved frequency standards. So far most of these experiments have concentrated on atomic ions. Recently, however, attention has also been focused on molecular species, and molecular nitrogen ions have been identified as promising candidates for testing a possible time-variation of the proton/electron mass ratio. Here, we report progress towards precision-spectroscopic studies on dipole-forbidden vibrational transitions in single trapped N2+ ions. Our approach relies on the state-selective generation of single N2+ ions, subsequent infrared excitation using high intensity, narrow-band quantum-cascade lasers and a quantum-logic scheme for non-destructive state readout. We also characterize processes limiting the state lifetimes in our experiment, which impair the measurement fidelity. P. O. Schmidt et. al., Science 309 (2005), 749. M. Kajita et. al., Phys. Rev. A 89 (2014), 032509 M. Germann , X. Tong, S. Willitsch, Nature Physics 10 (2014), 820. X. Tong, A. Winney, S. Willitsch, Phys. Rev. Lett. 105 (2010), 143001

  4. Vibrational Cooling in A Cold Ion Trap: Vibrationally Resolved Photoelectron Spectroscopy of Cold C60- Anions

    SciTech Connect

    Wang, Xue B.; Woo, Hin-koon; Wang, Lai S.

    2005-08-01

    We demonstrate vibrational cooling of anions via collisions with a background gas in an ion trap attached to a cryogenically controlled cold head (10 ? 400 K). Photoelectron spectra of vibrationally cold C60- anions, produced by electrospray ionization and cooled in the cold ion trap, have been obtained. Relative to spectra taken at room temperature, vibrational hot bands are completely eliminated, yielding well resolved vibrational structures and a more accurate electron affinity for neutral C60. The electron affinity of C60 is measured to be 2.683 ? 0.008 eV. The cold spectra reveal complicated vibrational structures for the transition to the C60 ground state due to the Jahn-Teller effect in the ground state of C60-. Vibrational excitations in the two Ag modes and eight Hg modes are observed, providing ideal data to assess the vibronic couplings in C60-.

  5. COLD TRAPS

    DOEpatents

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  6. Employing trapped cold ions to verify the quantum Jarzynski equality.

    PubMed

    Huber, Gerhard; Schmidt-Kaler, Ferdinand; Deffner, Sebastian; Lutz, Eric

    2008-08-15

    We propose a scheme to investigate the nonequilibrium work distribution of a quantum particle under well controlled transformations of the external potential, exploiting the versatility of a single ion in a segmented linear Paul trap. We describe in detail how the motional quantum state of a single ion can be prepared, manipulated, and finally readout to fully determine the free energy difference in both harmonic and anharmonic potentials. Uniquely to our system, we show how an ion may be immersed in an engineered laser-field reservoir. Trapped ions therefore represent an ideal tool for investigating the Jarzynski equality in open and closed quantum systems.

  7. COLD TRAP

    DOEpatents

    Milleron, N.

    1963-03-12

    An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

  8. Formation of molecular ions by radiative association of cold trapped atoms and ions

    NASA Astrophysics Data System (ADS)

    Dulieu, Olivier; da Silva, Humberto, Jr.; Aymar, Mireille; Raoult, Maurice

    2015-05-01

    Radiative emission during cold collisions between trapped laser-cooled Rb atoms and alkaline-earth ions (Ca+ , Sr+ , Ba+) and Yb+ are studied theoretically, using accurate effective-core-potential based quantum chemistry calculations of potential energy curves and transition dipole moments of the related molecular ions. Radiative association of molecular ions is predicted to occur for all systems with a cross section two to ten times larger than the radiative charge transfer one. Partial and total rate constants are also calculated and compared to available experiments. Narrow shape resonances are expected, which could be detectable at low temperature with an experimental resolution at the limit of the present standards. Vibrational distributions show that the final molecular ions are not created in their ground state level. Supported by the Marie-Curie ITN ``COMIQ: Cold Molecular Ions at the Quantum limit'' of the EU (#607491).

  9. Description of ion motion in a Paul trap immersed in a cold atomic gas

    NASA Astrophysics Data System (ADS)

    Krych, Michał; Idziaszek, Zbigniew

    2015-02-01

    We investigate the problem of a single ion in a radio-frequency trap immersed in an ultracold Bose gas in either a condensed or a noncondensed phase. We develop a master-equation formalism describing the sympathetic cooling, and we determine the cooling rates of ions. We show that the cold atomic reservoir modifies the stability diagram of the ion in the Paul trap, creating regions where the ion is either cooled or heated due to the energy quanta exchanged with the time-dependent potential.

  10. Measurement of the temperature of cold highly charged ions produced in an electron beam ion trap

    SciTech Connect

    Beiersdorfer, P.; Decaux, V.; Widmann, K.

    1994-09-14

    The temperature of highly charged titanium ions produced and trapped in an electron beam ion trap was determined by precisely measuring the broadening of the emission line profile caused by the thermal Doppler motion. The measured temperature ranges from about 700 eV for deeply trapped ions to about 70 eV for ions in a shallow trap. The latter value represents the lowest temperature at which the x-ray emission of collisonally excited heliumlike Ti{sup 20}+ ions has ever been recorded, and the measured transitions represent the narrowest x-ray lines observed from highly charged titanium ions.

  11. Bound-Free and Bound-Bound Spectroscopy of Cold Trapped Molecular Ions

    NASA Astrophysics Data System (ADS)

    Wester, Roland

    2016-06-01

    Cryogenic radiofrequency ion traps have become a versatile tool to study the spectroscopy and state-selected collision dynamics of molecular ions. Different types of action spectroscopy have been developed to obtain a precise and sensitive spectroscopic signature. In this talk I will give an introduction to molecular ion spectroscopy in multipole traps. Then I will present recent experimental and theoretical investigations from our group on photodetachment spectroscopy and state-selected collisions of cold OH- anions colliding with helium and hydrogen. Based on these results we performed high resolution terahertz spectroscopy on the two lowest rotational transitions of OD-. Work is in progress to extend the rotational spectroscopy to polyatomic molecular anions.

  12. Decoherence bounds on the capabilities of cold trapped ion quantum computers

    SciTech Connect

    James, D.F.V.; Hughes, R.J.; Knill, E.H.

    1997-05-01

    Using simple physical arguments we investigate the capabilities of a quantum computer based on cold trapped ions of the type recently proposed by Cirac and Zoller. From the limitations imposed on such a device by decoherence due to spontaneous decay, laser phase coherence times, ion heating and other possible sources of error, we derive bounds on the number of laser interactions and on the number of ions that may be used. As a quantitative measure of the possible performance of these devices, the largest number which may be factored using Shor`s quantum factoring algorithm is determined for a variety of species of ion.

  13. Liquid metal cold trap

    DOEpatents

    Hundal, Rolv

    1976-01-01

    A cold trap assembly for removing impurities from a liquid metal being provided with a hole between the incoming impure liquid metal and purified outgoing liquid metal which acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly.

  14. Dynamics of a Cold Trapped Ion in a Bose-Einstein Condensate

    SciTech Connect

    Schmid, Stefan; Haerter, Arne; Denschlag, Johannes Hecker

    2010-09-24

    We investigate the interaction of a laser-cooled trapped ion (Ba{sup +} or Rb{sup +}) with an optically confined {sup 87}Rb Bose-Einstein condensate. The system features interesting dynamics of the ion and the atom cloud as determined by their collisions and their motion in their respective traps. Elastic as well as inelastic processes are observed and their respective cross sections are determined. We demonstrate that a single ion can be used to probe the density profile of an ultracold atom cloud.

  15. Radial cold trap

    DOEpatents

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  16. Radial cold trap

    DOEpatents

    Grundy, Brian R.

    1981-01-01

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

  17. New Method for Double-Resonance Spectroscopy in a Cold Quadrupole Ion Trap and Its Application to UV-UV Hole-Burning Spectroscopy of Protonated Adenine Dimer.

    PubMed

    Kang, Hyuk; Féraud, Géraldine; Dedonder-Lardeux, Claude; Jouvet, Christophe

    2014-08-01

    A novel method for double-resonance spectroscopy in a cold quadrupole ion trap is presented, which utilizes dipolar resonant excitation of fragment ions in the quadrupole ion trap. Photofragments by a burn laser are removed by applying an auxiliary RF to the trap, and a probe laser detects the depletion of photofragments by the burn laser. By scanning the wavelength of the burn laser, conformation-specific UV spectrum of a cold ion is obtained. This simple and powerful method is applicable to any type of double-resonance spectroscopy in a cold quadrupole ion trap and was applied to UV-UV hole-burning spectroscopy of protonated adenine dimer. It was found that protonated adenine dimer has multiple conformers/tautomers, each with multiple excited states with drastically different excited state dynamics.

  18. Effect of Coulomb interaction on time of flight of cold antiprotons launched from an ion trap

    NASA Technical Reports Server (NTRS)

    Camp, J. B.; Witteborn, F. C.

    1993-01-01

    Time-of-flight spectra for Maxwell-Boltzman (MB) distributions of antiprotons initially held in an ion trap and detected after being launched through a 50-cm-long shielding drift tube have been calculated. The distributions used are of temperature 0.4-40 K, cubic length 0.003-3.0 cm, and number 10-100 particles. The mutual Coulomb repulsion of the particles causes a reduction in the number of late arrival particles expected from the MB velocity distribution. The Coulomb energy is not equally divided among the particles during the expansion. The energy is transferred preferentially to the outer particles so that the reduction in the number of slow particles is not necessarily large. The reduction factor is found to be greater than unity when the potential energy of the trapped ions is greater than about 5 percent of the ions' kinetic energy and is about 2 for the launch parameters of the Los Alamos antiproton gravity experiment.

  19. Cold Highly Charged Ions in a Penning Trap: Experiment and Simulation

    SciTech Connect

    Holder, J P; Gruber, L; Church, D A; Schneider, D

    2001-08-18

    Using the LLNL EBIT/RETRAP system non-neutral plasmas of highly charged ions were produced and cooled to temperatures around one Kelvin. These strongly coupled plasmas can model white dwarf astrophysical plasmas in the laboratory. These systems may also have potential application to quantum computation. The experimental results from the last operations of the trap at Livermore are discussed. Molecular dynamics simulation results are discussed as a guide to past and future experiments. The status and future plans for RETRAP at LBNL's 88 inch Cyclotron are discussed.

  20. Microfabricated ion trap array

    DOEpatents

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  1. Cold Strontium Ion Source for Ion Interferometry

    NASA Astrophysics Data System (ADS)

    Jackson, Jarom; Durfee, Dallin

    2015-05-01

    We are working on a cold source of Sr Ions to be used in an ion interferometer. The beam will be generated from a magneto-optical trap (MOT) of Sr atoms by optically ionizing atoms leaking out a carefully prepared hole in the MOT. A single laser cooling on the resonant transition (461 nm) in Sr should be sufficient for trapping, as we've calculated that losses to the atom beam will outweigh losses to dark states. Another laser (405 nm), together with light from the trapping laser, will drive a two photon transition in the atom beam to an autoionizing state. Supported by NSF Award No. 1205736.

  2. Trapping radioactive ions

    NASA Astrophysics Data System (ADS)

    Kluge, H.-J.; Blaum, K.

    2004-12-01

    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.

  3. Microfabricated cylindrical ion trap

    DOEpatents

    Blain, Matthew G.

    2005-03-22

    A microscale cylindrical ion trap, having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale cylindrical ion trap to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The microscale CIT has a reduced ion mean free path, allowing operation at higher pressures with less expensive and less bulky vacuum pumping system, and with lower battery power than conventional- and miniature-sized ion traps. The reduced electrode voltage enables integration of the microscale cylindrical ion trap with on-chip integrated circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of microscale cylindrical ion traps can be realized in truly field portable, handheld microanalysis systems.

  4. Ion trap device

    DOEpatents

    Ibrahim, Yehia M.; Smith, Richard D.

    2016-01-26

    An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

  5. Nonlinear integrable ion traps

    SciTech Connect

    Nagaitsev, S.; Danilov, V.; /SNS Project, Oak Ridge

    2011-10-01

    Quadrupole ion traps can be transformed into nonlinear traps with integrable motion by adding special electrostatic potentials. This can be done with both stationary potentials (electrostatic plus a uniform magnetic field) and with time-dependent electric potentials. These potentials are chosen such that the single particle Hamilton-Jacobi equations of motion are separable in some coordinate systems. The electrostatic potentials have several free adjustable parameters allowing for a quadrupole trap to be transformed into, for example, a double-well or a toroidal-well system. The particle motion remains regular, non-chaotic, integrable in quadratures, and stable for a wide range of parameters. We present two examples of how to realize such a system in case of a time-independent (the Penning trap) as well as a time-dependent (the Paul trap) configuration.

  6. Asymmetric ion trap

    DOEpatents

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  7. Asymmetric ion trap

    DOEpatents

    Barlow, S.E.; Alexander, M.L.; Follansbee, J.C.

    1997-12-02

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode is disclosed. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity. 4 figs.

  8. Ion trap in a semiconductor chip

    NASA Astrophysics Data System (ADS)

    Stick, D.; Hensinger, W. K.; Olmschenk, S.; Madsen, M. J.; Schwab, K.; Monroe, C.

    2006-01-01

    The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ions. Work on miniaturizing electromagnetic traps to the micrometre scale promises even higher levels of control and reliability. Compared with `chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass-spectrometer arrays, compact atomic clocks and, most notably, large-scale quantum information processors. Here we report the operation of a micrometre-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium-arsenide heterostructure.

  9. Computing rotational energy transfers of OD-/OH- in collisions with Rb: isotopic effects and inelastic rates at cold ion-trap conditions

    NASA Astrophysics Data System (ADS)

    González-Sánchez, L.; Gianturco, F. A.; Carelli, F.; Wester, R.

    2015-12-01

    We report close-coupling (CC) quantum dynamics calculations for collisional excitation/de-excitation of the lowest four rotational levels of OD- and of OH- interacting with Rb atoms in a cold ion trap. The calculations are carried out over a range of energies capable of yielding the corresponding rates for state-changing events over a rather broad interval of temperatures which cover those reached in earlier cold trap experiments. They involved sympathetic cooling of the molecular anion through a cloud of laser-cooled Rb atoms, an experiment which is currently being run again through a Heidelberg-Innsbruck collaboration. The significance of isotopic effects is analysed by comparing both systems and the range of temperatures examined in the calculations is extended up to 400 K, starting from a few mK. Both cross sections and rates are found to be markedly larger than in the case of OD-/OH- interacting the He atoms under the same conditions, and the isotopic effects are also seen to be rather significant at the energies examined in the present study. Such findings are discussed in the light of the observed trap losses of molecular anions.

  10. Rydberg Excitation of a Single Trapped Ion.

    PubMed

    Feldker, T; Bachor, P; Stappel, M; Kolbe, D; Gerritsma, R; Walz, J; Schmidt-Kaler, F

    2015-10-23

    We demonstrate excitation of a single trapped cold (40)Ca(+) ion to Rydberg levels by laser radiation in the vacuum ultraviolet at a wavelength of 122 nm. Observed resonances are identified as 3d(2)D(3/2) to 51F, 52F and 3d(2)D(5/2) to 64F. We model the line shape and our results imply a large state-dependent coupling to the trapping potential. Rydberg ions are of great interest for future applications in quantum computing and simulation, in which large dipolar interactions are combined with the superb experimental control offered by Paul traps. PMID:26551109

  11. Modeling and Optimizing RF Multipole Ion Traps

    NASA Astrophysics Data System (ADS)

    Fanghaenel, Sven; Asvany, Oskar; Schlemmer, Stephan

    2016-06-01

    Radio frequency (rf) ion traps are very well suited for spectroscopy experiments thanks to the long time storage of the species of interest in a well defined volume. The electrical potential of the ion trap is determined by the geometry of its electrodes and the applied voltages. In order to understand the behavior of trapped ions in realistic multipole traps it is necessary to characterize these trapping potentials. Commercial programs like SIMION or COMSOL, employing the finite difference and/or finite element method, are often used to model the electrical fields of the trap in order to design traps for various purposes, e.g. introducing light from a laser into the trap volume. For a controlled trapping of ions, e.g. for low temperature trapping, the time dependent electrical fields need to be known to high accuracy especially at the minimum of the effective (mechanical) potential. The commercial programs are not optimized for these applications and suffer from a number of limitations. Therefore, in our approach the boundary element method (BEM) has been employed in home-built programs to generate numerical solutions of real trap geometries, e.g. from CAD drawings. In addition the resulting fields are described by appropriate multipole expansions. As a consequence, the quality of a trap can be characterized by a small set of multipole parameters which are used to optimize the trap design. In this presentation a few example calculations will be discussed. In particular the accuracy of the method and the benefits of describing the trapping potentials via multipole expansions will be illustrated. As one important application heating effects of cold ions arising from non-ideal multipole fields can now be understood as a consequence of imperfect field configurations.

  12. Cold atoms in videotape micro-traps

    NASA Astrophysics Data System (ADS)

    Sinclair, C. D. J.; Retter, J. A.; Curtis, E. A.; Hall, B. V.; Llorente Garcia, I.; Eriksson, S.; Sauer, B. E.; Hinds, E. A.

    2005-08-01

    We describe an array of microscopic atom traps formed by a pattern of magnetisation on a piece of videotape. We describe the way in which cold atoms are loaded into one of these micro-traps and how the trapped atom cloud is used to explore the properties of the trap. Evaporative cooling in the micro-trap down to a temperature of 1~μK allows us to probe the smoothness of the trapping potential and reveals some inhomogeneity produced by the magnetic film. We discuss future prospects for atom chips based on microscopic permanent-magnet structures.

  13. Modeling the Stability of Volatile Deposits in Lunar Cold Traps

    NASA Technical Reports Server (NTRS)

    Crider, D. H.; Vondrak, R. R.

    2002-01-01

    There are several mechanisms acting at the cold traps that can alter the inventory of volatiles there. Primarily, the lunar surface is bombarded by meteoroids which impact, melt, process, and redistribute the regolith. Further, solar wind and magnetospheric ion fluxes are allowed limited access onto the regions in permanent shadow. Also, although cold traps are in the permanent shadow of the Sun, there is a small flux of radiation incident on the regions from interstellar sources. We investigate the effects of these space weathering processes on a deposit of volatiles in a lunar cold trap through simulations. We simulate the development of a column of material near the surface of the Moon resulting from space weathering. This simulation treats a column of material at a lunar cold trap and focuses on the hydrogen content of the column. We model space weathering processes on several time and spatial scales to simulate the constant rain of micrometeoroids as well as sporadic larger impactors occurring near the cold traps to determine the retention efficiency of the cold traps. We perform the Monte Carlo simulation over many columns of material to determine the expectation value for hydrogen content of the top few meters of soil for comparison with Lunar Prospector neutron data.

  14. Dynamics Of Ions In A Radio-Frequency Quadrupole Trap

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Williams, Angelyn P.; Maleki, Lutfollah

    1994-01-01

    Report describes computer-simulation study of motions of various numbers of ions in Paul trap. Study part of continuing effort to understand motions of trapped charged particles (atoms, ions, molecules, or dust particles). Motions characterized in terms of heating by radio-frequency fields, formation of crystallike structures in cold clouds of trapped particles, and other phenomena important in operation of radio-frequency traps in frequency standards.

  15. Quantum computing with trapped ions

    SciTech Connect

    Hughes, R.J.

    1998-01-01

    The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

  16. Halo ion trap mass spectrometer.

    PubMed

    Austin, Daniel E; Wang, Miao; Tolley, Samuel E; Maas, Jeffrey D; Hawkins, Aaron R; Rockwood, Alan L; Tolley, H Dennis; Lee, Edgar D; Lee, Milton L

    2007-04-01

    We describe a novel radio frequency ion trap mass analyzer based on toroidal trapping geometry and microfabrication technology. The device, called the halo ion trap, consists of two parallel ceramic plates, the facing surfaces of which are imprinted with sets of concentric ring electrodes. Radii of the imprinted rings range from 5 to 12 mm, and the spacing between the plates is 4 mm. Unlike conventional ion traps, in which hyperbolic metal electrodes establish equipotential boundary conditions, electric fields in the halo ion trap are established by applying different radio frequency potentials to each ring. The potential on each ring can be independently optimized to provide the best trapping field. The halo ion trap features an open structure, allowing easy access for in situ ionization. The toroidal geometry provides a large trapping and analyzing volume, increasing the number of ions that can be stored and reducing the effects of space-charge on mass analysis. Preliminary mass spectra show resolution (m/Deltam) of 60-75 when the trap is operated at 1.9 MHz and 500 Vp-p. PMID:17335180

  17. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  18. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  19. Ion funnel ion trap and process

    DOEpatents

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  20. Universal collisional activation ion trap mass spectrometry

    DOEpatents

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1993-04-27

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  1. Universal collisional activation ion trap mass spectrometry

    DOEpatents

    McLuckey, Scott A.; Goeringer, Douglas E.; Glish, Gary L.

    1993-01-01

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  2. Lunar Cold Trap Contamination by Landing Vehicles

    NASA Technical Reports Server (NTRS)

    Shipley, Scott T.; Metzger, Philip T.; Lane, John E.

    2014-01-01

    Tools have been developed to model and simulate the effects of lunar landing vehicles on the lunar environment (Metzger, 2011), mostly addressing the effects of regolith erosion by rocket plumes and the fate of the ejected lunar soil particles (Metzger, 2010). These tools are being applied at KSC to predict ejecta from the upcoming Google Lunar X-Prize Landers and how they may damage the historic Apollo landing sites. The emerging interest in lunar mining poses a threat of contamination to pristine craters at the lunar poles, which act as "cold traps" for water and may harbor other valuable minerals Crider and Vondrak (2002). The KSC Granular Mechanics and Regolith Operations Lab tools have been expanded to address the probability for contamination of these pristine "cold trap" craters.

  3. Trapping cold ground state argon atoms.

    PubMed

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  4. Ion trapping in Recycler Ring

    SciTech Connect

    K.Y. Ng

    2004-06-28

    Transverse instabilities have been observed in the antiproton beam stored in the Fermilab Recycler Ring, resulting in a sudden increase in the transverse emittances and a small beam loss. The instabilities appear to occur a few hours after a change in the ramping pattern of the Main Injector which shares the same tunnel. The phenomena have been studied by inducing similar instabilities. However, the mechanism is still unknown. A possible explanation is that the ions trapped in the beam reach such an intensity that collective coupled transverse oscillation occurs. However, there is no direct evidence of the trapped ions at this moment.

  5. Experimental investigation of planar ion traps

    SciTech Connect

    Pearson, C. E.; Leibrandt, D. R.; Bakr, W. S.; Mallard, W. J.; Brown, K. R.; Chuang, I. L.

    2006-03-15

    Chiaverini et al. [Quantum Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion-trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many-zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of charged particles of 0.44 {mu}m diameter in a vacuum of 15 Pa (10{sup -1} torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion-trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four-rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional dc-biased electrode above the trap which increases the trap depth dramatically, and a planar ion-trap geometry that generates a two-dimensional lattice of point Paul traps.

  6. EDITORIAL: Modern applications of trapped ions Modern applications of trapped ions

    NASA Astrophysics Data System (ADS)

    Knoop, Martina; Hilico, Laurent; Eschner, Jürgen

    2009-08-01

    investigation of cold molecular ions and clusters are among the fastest growing topics, leading to ultracold chemistry at the single-particle scale. The next edition of this meeting series will take the name of European Conference on Trapped Ions (ECTI) and will be held in the UK in 2010. We are looking forward to this event, which will offer the possibility to continue the fruitful interaction between research groups that employ ion traps in widely different contexts, and to take the next snapshot of this dynamic research area.

  7. Note: High density pulsed molecular beam for cold ion chemistry.

    PubMed

    Kokish, M G; Rajagopal, V; Marler, J P; Odom, B C

    2014-08-01

    A recent expansion of cold and ultracold molecule applications has led to renewed focus on molecular species preparation under ultrahigh vacuum conditions. Meanwhile, molecular beams have been used to study gas phase chemical reactions for decades. In this paper, we describe an apparatus that uses pulsed molecular beam technology to achieve high local gas densities, leading to faster reaction rates with cold trapped ions. We characterize the beam's spatial profile using the trapped ions themselves. This apparatus could be used for preparation of molecular species by reactions requiring excitation of trapped ion precursors to states with short lifetimes or for obtaining a high reaction rate with minimal increase of background chamber pressure.

  8. Note: High density pulsed molecular beam for cold ion chemistry

    SciTech Connect

    Kokish, M. G.; Rajagopal, V.; Marler, J. P.; Odom, B. C.

    2014-08-15

    A recent expansion of cold and ultracold molecule applications has led to renewed focus on molecular species preparation under ultrahigh vacuum conditions. Meanwhile, molecular beams have been used to study gas phase chemical reactions for decades. In this paper, we describe an apparatus that uses pulsed molecular beam technology to achieve high local gas densities, leading to faster reaction rates with cold trapped ions. We characterize the beam's spatial profile using the trapped ions themselves. This apparatus could be used for preparation of molecular species by reactions requiring excitation of trapped ion precursors to states with short lifetimes or for obtaining a high reaction rate with minimal increase of background chamber pressure.

  9. Microfabricated linear Paul-Straubel ion trap

    DOEpatents

    Mangan, Michael A.; Blain, Matthew G.; Tigges, Chris P.; Linker, Kevin L.

    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.

  10. Microscale ion trap mass spectrometer

    DOEpatents

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  11. A Cold Strontium Ion Source

    NASA Astrophysics Data System (ADS)

    Erickson, Christopher J.; Lyon, Mary; Blaser, Kelvin; Harper, Stuart; Durfee, Dallin

    2010-03-01

    We present a cold ion source for strontium 87. The source is based off of a standard Low-Velocity-Intense-Source (LVIS) for strontium using permanent magnets in place of anti-Helmholtz coils. Atoms from the LVIS are then ionized in a two photon process as they pass a 20kV anode plate. The result is a mono-energetic beam of ions whose velocity is tunable. Applications for the ions include spectroscopy and ion interferometry.

  12. Cryogenic ion trapping systems with surface-electrode traps.

    PubMed

    Antohi, P B; Schuster, D; Akselrod, G M; Labaziewicz, J; Ge, Y; Lin, Z; Bakr, W S; Chuang, I L

    2009-01-01

    We present two simple cryogenic rf ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 h. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The vibration amplitude of the closed cycled cryostat was found to be below 106 nm. We evaluated the systems by loading surface-electrode ion traps with (88)Sr(+) ions using laser ablation, which is compatible with the cryogenic environment. Using Doppler cooling we observed small ion crystals in which optically resolved ions have a trapped lifetime over 2500 min.

  13. Study of Cold Potassium Atom - Calcium Ion Reactions

    NASA Astrophysics Data System (ADS)

    Egodapitiya, Kisra; Gang, Shu; Clark, Robert; Brown, Kenneth

    2016-05-01

    We report on our progress towards constructing a hybrid system for studying reactions between cold Potassium (K) atoms and cold Calcium (Ca+) ions. Ca+ ions will be trapped and Doppler-cooled inside a linear quadrupole ion trap. Cold K atoms will be created inside a magneto optical trap, such that the ion and the atoms are in an overlapping volume. Trapping and re-pumping beams for the Potassium MOT are derived from the same laser with wavelength 766 nm using two acousto optic modulators. The reaction products will be detected using a time-of- flight mass spectrometer that is designed to detect radially ejected ions. The main objective of this experiment is to study the rate coefficients, and identification of reaction channels between cold K atoms and Ca+ ions. Subsequently this setup will be used to study reactions between cold K atoms and sympathetically cooled molecular ions such as CaO+, and to study internal state quenching of molecular ions.

  14. Scalable Designs for Planar Ion Trap Arrays

    NASA Astrophysics Data System (ADS)

    Slusher, R. E.

    2007-03-01

    Recent progress in quantum operations with trapped ion qubits has been spectacular for qubit counts up to approximately ten ions. Two qubit quantum gates, quantum error correction, simple quantum algorithms and entanglement of up to 8 qubits have been demonstrated by groups including those at NIST, University of Michigan, University of Innsbruck and Oxford. Interesting problems in quantum information processing including quantum simulations of condensed matter systems and quantum repeaters for long distance quantum communication systems require hundreds or thousands of qubits. Initial designs for an ion trap ``Quantum CCD'' using spatially multiplexed planar ion traps as well as initial experiments using planar ion traps are promising routes to scaling up the number of trapped ions to more interesting levels. We describe designs for planar ion traps fabricated using silicon VLSI techniques. This approach allows the control voltages required for the moving and positioning the ions in the array to be connected vertically through the silicon substrate to underlying CMOS electronics. We have developed techniques that allow the ion trap structures to be fabricated monolithically on top of the CMOS electronics. The planar traps have much weaker trapping depths than the more conventional multi-level traps. However, the trap depths are still adequate for trapping hot ions from many ion sources. The planar traps also involve more complex configurations for laser cooling and micromotion control. Initial solutions to these problems will be presented. Laser access to the ions can be provided by laser beams grazing the trap surface or by using vertical slots through the trap chip. We will also discuss limits imposed by power dissipation and ion transport through trap junctions (e.g. crosses and Ys). We have fabricated these VLSI based traps in a number of configurations. Initial fabrication and packaging challenges will be discussed. D. Kielpinski, C. Monroe, and D.J. Wineland

  15. Improved Linear-Ion-Trap Frequency Standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.

    1995-01-01

    Improved design concept for linear-ion-trap (LIT) frequency-standard apparatus proposed. Apparatus contains lengthened linear ion trap, and ions processed alternately in two regions: ions prepared in upper region of trap, then transported to lower region for exposure to microwave radiation, then returned to upper region for optical interrogation. Improved design intended to increase long-term frequency stability of apparatus while reducing size, mass, and cost.

  16. Ion temperature gradient driven turbulence with strong trapped ion resonance

    SciTech Connect

    Kosuga, Y.; Itoh, S.-I.; Diamond, P. H.; Itoh, K.; Lesur, M.

    2014-10-15

    A theory to describe basic characterization of ion temperature gradient driven turbulence with strong trapped ion resonance is presented. The role of trapped ion granulations, clusters of trapped ions correlated by precession resonance, is the focus. Microscopically, the presence of trapped ion granulations leads to a sharp (logarithmic) divergence of two point phase space density correlation at small scales. Macroscopically, trapped ion granulations excite potential fluctuations that do not satisfy dispersion relation and so broaden frequency spectrum. The line width from emission due only to trapped ion granulations is calculated. The result shows that the line width depends on ion free energy and electron dissipation, which implies that non-adiabatic electrons are essential to recover non-trivial dynamics of trapped ion granulations. Relevant testable predictions are summarized.

  17. Atomic Clock Based On Linear Ion Trap

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. John

    1992-01-01

    Highly stable atomic clock based on excitation and measurement of hyperfine transition in 199Hg+ ions confined in linear quadrupole trap by radio-frequency and static electric fields. Configuration increases stability of clock by enabling use of enough ions to obtain adequate signal while reducing non-thermal component of motion of ions in trapping field, reducing second-order Doppler shift of hyperfine transition. Features described in NPO-17758 "Linear Ion Trap for Atomic Clock." Frequency standard based on hyperfine transition described in NPO-17456, "Trapped-Mercury-Ion Frequency Standard."

  18. Trapped-Mercury-Ion Frequency Standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. John; Maleki, Lutfollah

    1991-01-01

    Report describes principle of operation, design, and results of initial measurements on trapped-mercury-ion frequency-standard apparatus at NASA's Jet Propulsion Laboratory. New frequency standard being developed. Based on linear ion trap described in (NPO-17758). Expected to show much better short-term frequency stability because of increased ion-storage capacity.

  19. New ion trap for frequency standard applications

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Dick, G. J.; Maleki, L.

    1989-01-01

    A novel linear ion trap was designed, which permits storage of a large number of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. This new trap should store about 20 times the number of ions as a conventional RF trap with no corresponding increase in second-order Doppler shift from the confining field. In addition, the sensitivity of this shift to trapping parameters, i.e., RF voltage, RF frequency, and trap size, is greatly reduced.

  20. Manipulating cold atoms with off-axis rotating traps

    NASA Astrophysics Data System (ADS)

    Oh, Eun; Du, Shengwang

    2013-08-01

    We investigate classical motions of cold atoms in three types (harmonic, linear, and Gaussian) of off-axis rotating traps in the presence of damping forces. When the radius of rotation of the trap is within the trap volume, the atoms are always attracted towards the rotation's origin if the damping rate Γ is larger than the trap frequency ω ( i.e., Γ > ω). This is opposed to being repelled by the centrifugal force in a rotating reference frame. Contrarily, when the trap's rotation radius is larger than the trap size, the atoms experience a time-averaged ring-shape trap at a high rotational frequency. These anomalous properties can be used to realize high-speed rotation sensors and effective static ring-trap potentials for manipulating cold atoms.

  1. Non-destructive ion trap mass spectrometer and method

    DOEpatents

    Frankevich, Vladimir E.; Soni, Manish H.; Nappi, Mario; Santini, Robert E.; Amy, Jonathan W.; Cooks, Robert G.

    1997-01-01

    The invention relates to an ion trap mass spectrometer of the type having an ion trapping volume defined by spaced end caps and a ring electrode. The ion trap includes a small sensing electrode which senses characteristic motion of ions trapped in said trapping volume and provides an image current. Ions are excited into characteristic motion by application of an excitation pulse to the trapped ions. The invention also relates to a method of operating such an ion trap.

  2. Antihydrogen from merged plasmas - cold enough to trap?

    SciTech Connect

    Madsen, Niels

    2006-10-18

    The merging of antiprotons with a positron plasma is the predominant and highest efficient method for cold antihydrogen formation used to date. We present experimental evidence that this method has serious disadvantages for producing antihydrogen cold enough to be trapped. Antihydrogen is neutral but may be trapped in a magnetic field minimum. However, the depth of such traps are of order 1 K, shallow compared to the kinetic energies in current antihydrogen experiments. Studying the spatial distribution of the antihydrogen emerging from the ATHENA positron plasma we have, by comparison with a simple model, extracted information about the temperature of the antihydrogen formed. We find that antihydrogen is formed before thermal equilibrium is attained between the antiprotons and the positrons, and thus that further positron cooling may not be sufficient for producing antihydrogen cold enough to be trapped. We discuss the implications for trapping of antihydrogen in a magnetic trap, important for ongoing work by the ALPHA collaboration.

  3. Three-Rod Linear Ion Traps

    NASA Technical Reports Server (NTRS)

    Janik, Gary R.; Prestage, John D.; Maleki, Lutfollah

    1993-01-01

    Three-parallel-rod electrode structures proposed for use in linear ion traps and possibly for electrostatic levitation of macroscopic particles. Provides wider viewing angle because they confine ions in regions outside rod-electrode structures.

  4. Trapped Ion Optical Clocks at NPL

    SciTech Connect

    Margolis, H. S.; Barwood, G. P.; Hosaka, K.; Klein, H. A.; Lea, S. N.; Walton, B. R.; Webster, S. A.; Gill, P.; Huang, G.; Stannard, A.

    2006-11-07

    Forbidden transitions in single laser-cooled trapped ions provide highly stable and accurate references for optical frequency standards. This paper describes recent progress on strontium and ytterbium ion optical frequency standards under development at NPL.

  5. Quantum Information Processing with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Roos, Christian

    Trapped ions constitute a well-isolated small quantum system that offers low decoherence rates and excellent opportunities for quantum control and measurement by laser-induced manipulation of the ions. These properties make trapped ions an attractive system for experimental investigations of quantum information processing. In the following, the basics of storing, manipulating and measuring quantum information encoded in a string of trapped ions will be discussed. Based on these techniques, entanglement can be created and simple quantum protocols like quantum teleportation be realized. This chapter concludes with a discussion of the use of entangling laser-ion interactions for quantum simulations and quantum logic spectroscopy.

  6. Atomic ion clock with two ion traps, and method to transfer ions

    NASA Technical Reports Server (NTRS)

    Prestage, John D. (Inventor); Chung, Sang K. (Inventor)

    2011-01-01

    An atomic ion clock with a first ion trap and a second ion trap, where the second ion trap is of higher order than the first ion trap. In one embodiment, ions may be shuttled back and forth from one ion trap to the other by application of voltage ramps to the electrodes in the ion traps, where microwave interrogation takes place when the ions are in the second ion trap, and fluorescence is induced and measured when the ions are in the first ion trap. In one embodiment, the RF voltages applied to the second ion trap to contain the ions are at a higher frequency than that applied to the first ion trap. Other embodiments are described and claimed.

  7. Ion traps fabricated in a CMOS foundry

    SciTech Connect

    Mehta, K. K.; Ram, R. J.; Eltony, A. M.; Chuang, I. L.; Bruzewicz, C. D.; Sage, J. M. Chiaverini, J.

    2014-07-28

    We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This demonstration of scalable quantum computing hardware utilizing a commercial CMOS process opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.

  8. Cryptography, quantum computation and trapped ions

    SciTech Connect

    Hughes, Richard J.

    1998-03-01

    The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

  9. Spectroscopy with trapped highly charged ions

    SciTech Connect

    Beiersdorfer, P

    2008-01-23

    We give an overview of atomic spectroscopy performed on electron beam ion traps at various locations throughout the world. Spectroscopy at these facilities contributes to various areas of science and engineering, including but not limited to basic atomic physics, astrophysics, extreme ultraviolet lithography, and the development of density and temperature diagnostics of fusion plasmas. These contributions are accomplished by generating, for example, spectral surveys, making precise radiative lifetime measurements, accounting for radiative power emitted in a given wavelength band, illucidating isotopic effects, and testing collisional-radiative models. While spectroscopy with electron beam ion traps had originally focused on the x-ray emission from highly charged ions interacting with the electron beam, the operating modes of such devices have expanded to study radiation in almost all wavelength bands from the visible to the hard x-ray region; and at several facilities the ions can be studied even in the absence of an electron beam. Photon emission after charge exchange or laser excitation has been observed, and the work is no longer restricted to highly charged ions. Much of the experimental capabilities are unique to electron beam ion traps, and the work performed with these devices cannot be undertaken elsewhere. However, in other areas the work on electron beam ion traps rivals the spectroscopy performed with conventional ion traps or heavy-ion storage rings. The examples we present highlight many of the capabilities of the existing electron beam ion traps and their contributions to physics.

  10. Cooling of highly charged ions in a Penning trap

    SciTech Connect

    Gruber, L

    2000-03-31

    Highly charged ions are extracted from an electron beam ion trap and guided to Retrap, a cryogenic Penning trap, where they are merged with laser cooled Be{sup +} ions. The Be{sup +} ions act as a coolant for the hot highly charged ions and their temperature is dropped by about 8 orders of magnitude in a few seconds. Such cold highly charged ions form a strongly coupled nonneutral plasma exhibiting, under such conditions, the aggregation of clusters and crystals. Given the right mixture, these plasmas can be studied as analogues of high density plasmas like white dwarf interiors, and potentially can lead to the development of cold highly charged ion beams for applications in nanotechnology. Due to the virtually non existent Doppler broadening, spectroscopy on highly charged ions can be performed to an unprecedented precision. The density and the temperature of the Be{sup +} plasma were measured and highly charged ions were sympathetically cooled to similar temperatures. Molecular dynamics simulations confirmed the shape, temperature and density of the highly charged ions. Ordered structures were observed in the simulations.

  11. Nonlinear spectroscopy of trapped ions

    NASA Astrophysics Data System (ADS)

    Schlawin, Frank; Gessner, Manuel; Mukamel, Shaul; Buchleitner, Andreas

    2014-08-01

    Nonlinear spectroscopy employs a series of laser pulses to interrogate dynamics in large interacting many-body systems, and it has become a highly successful method for experiments in chemical physics. Current quantum optical experiments approach system sizes and levels of complexity that require the development of efficient techniques to assess spectral and dynamical features with scalable experimental overhead. However, established methods from optical spectroscopy of macroscopic ensembles cannot be applied straightforwardly to few-atom systems. Based on the ideas proposed in M. Gessner et al., (arXiv:1312.3365), we develop a diagrammatic approach to construct nonlinear measurement protocols for controlled quantum systems, and we discuss experimental implementations with trapped ion technology in detail. These methods, in combination with distinct features of ultracold-matter systems, allow us to monitor and analyze excitation dynamics in both the electronic and vibrational degrees of freedom. They are independent of system size, and they can therefore reliably probe systems in which, e.g., quantum state tomography becomes prohibitively expensive. We propose signals that can probe steady-state currents, detect the influence of anharmonicities on phonon transport, and identify signatures of chaotic dynamics near a quantum phase transition in an Ising-type spin chain.

  12. Entanglement of Multiple Trapped Ions

    NASA Astrophysics Data System (ADS)

    Sackett, C. A.

    2000-06-01

    Quantum mechanics allows for many-particle wave functions which cannot be factorized into a product of single-particle wave functions, even when the constituent particles are entirely distinct. Such entangled states explicitly demonstrate the nonclassical correlations of quantum theory,(See for instance J. Bell, Speakable and Unspeakable in Quantum Mechanics). (Cambridge Univ. Press, Cambridge, 1987); J.-W. Pan, D. Bouwmeester, M. Daniell, H. Weinfurter, and A. Zeilinger, Nature 403, 515 (2000). have been suggested for use in high-precision spectroscopy,( J. Bollinger, W.M. Itano, D. Wineland, and D. Heinzen, Phys. Rev. A) 54, R4649 (1996). and are a fundamental element of schemes for quantum communication, cryptography, and computation.(See for instance H.-K Lo, S. Popescu, and T. Spiller, editors, Introduction to Quantum Computation and Information). (World Scientific, Singapore, 1997). In general, the more particles which can be entangled, the more useful the states are for quantum applications. In pursuit of these goals, we have demonstrated an entanglement technique which is applicable to any number of trapped ions.(K. Mølmer and A. Sørensen, Phys. Rev. Lett.) 82, 1835 (1999). We have used this technique to generate entangled states of two, and for the first time, four atoms.

  13. Simple analytic potentials for linear ion traps

    NASA Technical Reports Server (NTRS)

    Janik, G. R.; Prestage, J. D.; Maleki, L.

    1990-01-01

    A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potential and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency.

  14. Simple analytic potentials for linear ion traps

    NASA Technical Reports Server (NTRS)

    Janik, G. R.; Prestage, J. D.; Maleki, L.

    1989-01-01

    A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potenital and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency.

  15. Magnetic trapping of cold bromine atoms.

    PubMed

    Rennick, C J; Lam, J; Doherty, W G; Softley, T P

    2014-01-17

    Magnetic trapping of bromine atoms at temperatures in the millikelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br2 molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are lost only by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential.

  16. Interchange mode excited by trapped energetic ions

    SciTech Connect

    Nishimura, Seiya

    2015-07-15

    The kinetic energy principle describing the interaction between ideal magnetohydrodynamic (MHD) modes with trapped energetic ions is revised. A model is proposed on the basis of the reduced ideal MHD equations for background plasmas and the bounce-averaged drift-kinetic equation for trapped energetic ions. The model is applicable to large-aspect-ratio toroidal devices. Specifically, the effect of trapped energetic ions on the interchange mode in helical systems is analyzed. Results show that the interchange mode is excited by trapped energetic ions, even if the equilibrium states are stable to the ideal interchange mode. The energetic-ion-induced branch of the interchange mode might be associated with the fishbone mode in helical systems.

  17. Trapping low-energy antiprotons in an ion trap

    SciTech Connect

    Fei, Xiang.

    1990-01-01

    A fraction of antiprotons from the Low Energy Antiproton Ring (LEAR) of CERN are slowed from 5.9 MeV to below 3 keV as they pass through thin foils. Transmitted particle energy distribution and low energy antiproton yield are measured by a time-of-flight technique. The difference in the range of protons and antiprotons (known as the Barkas effect) is observed. While still in flight, up to 1.3 {times} 10{sup 5} antiprotons with energies between 0 eV to 3 keV are stored in an ion trap from a single pulse of 5.9 MeV antiprotons leaving LEAR, thus a trapping efficiency exceeding of 4 {times} 10{sup {minus}4} is established. Trapped antiprotons maintain their initial energy distribution unless allowed to collide with a cloud of trapped electrons, whereupon they slow and cool below 1 meV in 10 s, and fall into a harmonic potential well suited for precision mass measurements. The slowing, trapping and cooling of antiprotons are the main focus of this thesis. The stored antiprotons are in thermal equilibrium at 4.2 K. In this ion trap, the antiproton cyclotron frequency is measured and compared with the proton (or electron) cyclotron frequency. The new measured ratio of the antiproton and proton inertial masses, with its 4 {times} 10{sup {minus}8} uncertainty, is more than three orders of magnitude more accurate than previous measurements using exotic atoms. This is a most precise test of CPT invariance with baryons. The antiproton lifetime in an ion trap was measured to be more than 103 days by trapping a cloud of antiprotons for 59 days. The indicates the number density of atoms is less than 100/cm{sup 3} which corresponds to the pressure in the vacuum chamber being less than 5 {times} 10{sup {minus}17} Torr at 4.2 K if we apply the ideal gas law.

  18. The ALPHA Experiment: A Cold Antihydrogen Trap

    SciTech Connect

    Bertsche, W.; Chapman, S.; Deutsch, A.; Fajans, J.; Gomberoff, K.; Wurtele, J.; Boston, A.; Chartier, M.; Nolan, P.; Page, R.D.; Bowe, P.D.; Hangst, J.S.; Madsen, N.; Cesar, C.L.; Miranda, D.; Charlton, M.; Jenkins, M.; Joergensen, L.V.; Telle, H.H.; Werf, D.P. van der

    2005-10-26

    The ALPHA experiment aims to trap antihydrogen as the next crucial step towards a precise CPT test, by a spectroscopic comparison of antihydrogen with hydrogen. The experiment will retain the salient techniques developed by the ATHENA collaboration during the previous phase of antihydrogen experiments at the antiproton decelerator (AD) at CERN. The collaboration has identified the key problems in adding a neutral antiatom trap to the previously developed experimental configuration. The solutions identified by ALPHA are described in this paper.

  19. Scaling the ion trap quantum processor.

    PubMed

    Monroe, C; Kim, J

    2013-03-01

    Trapped atomic ions are standards for quantum information processing, serving as quantum memories, hosts of quantum gates in quantum computers and simulators, and nodes of quantum communication networks. Quantum bits based on trapped ions enjoy a rare combination of attributes: They have exquisite coherence properties, they can be prepared and measured with nearly 100% efficiency, and they are readily entangled with each other through the Coulomb interaction or remote photonic interconnects. The outstanding challenge is the scaling of trapped ions to hundreds or thousands of qubits and beyond, at which scale quantum processors can outperform their classical counterparts in certain applications. We review the latest progress and prospects in that effort, with the promise of advanced architectures and new technologies, such as microfabricated ion traps and integrated photonics.

  20. Cold Atom Source Containing Multiple Magneto-Optical Traps

    NASA Technical Reports Server (NTRS)

    Ramirez-Serrano, Jaime; Kohel, James; Kellogg, James; Lim, Lawrence; Yu, Nan; Maleki, Lute

    2007-01-01

    An apparatus that serves as a source of a cold beam of atoms contains multiple two-dimensional (2D) magneto-optical traps (MOTs). (Cold beams of atoms are used in atomic clocks and in diverse scientific experiments and applications.) The multiple-2D-MOT design of this cold atom source stands in contrast to single-2D-MOT designs of prior cold atom sources of the same type. The advantages afforded by the present design are that this apparatus is smaller than prior designs.

  1. Cavity QED in a molecular ion trap

    SciTech Connect

    Schuster, D. I.; Bishop, Lev S.; Chuang, I. L.; DeMille, D.; Schoelkopf, R. J.

    2011-01-15

    We propose a class of experiments using rotational states of dipolar molecular ions trapped near an on-chip superconducting microwave cavity. Molecular ions have several advantages over neutral molecules for such cavity quantum electrodynamics experiments. In particular, ions can be loaded easily into deep rf traps and are held independent of their internal state. An analysis of the detection efficiency for, and coherence properties of, the molecular ions is presented. We discuss approaches for manipulating quantum information and performing high-resolution rotational spectroscopy using this system.

  2. Ion-Atom Cold Collisions and Atomic Clocks

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Maleki, Lute; Tjoelker, Robert L.

    1997-01-01

    Collisions between ultracold neutral atoms have for some time been the subject of investigation, initially with hydrogen and more recently with laser cooled alkali atoms. Advances in laser cooling and trapping of neutral atoms in a Magneto-Optic Trap (MOT) have made cold atoms available as the starting point for many laser cooled atomic physics investigations. The most spectacularly successful of these, the observation of Bose-Einstein Condensation (BEC) in a dilute ultra-cold spin polarized atomic vapor, has accelerated the study of cold collisions. Experimental and theoretical studies of BEC and the long range interaction between cold alkali atoms is at the boundary of atomic and low temperature physics. Such studies have been difficult and would not have been possible without the development and advancement of laser cooling and trapping of neutral atoms. By contrast, ion-atom interactions at low temperature, also very difficult to study prior to modern day laser cooling, have remained largely unexplored. But now, many laboratories worldwide have almost routine access to cold neutral atoms. The combined technologies of ion trapping, together with laser cooling of neutrals has made these studies experimentally feasible and several very important, novel applications might come out of such investigations . This paper is an investigation of ion-atom interactions in the cold and ultra-cold temperature regime. Some of the collisional ion-atom interactions present at room temperature are very much reduced in the low temperature regime. Reaction rates for charge transfer between unlike atoms, A + B(+) approaches A(+) + B, are expected to fall rapidly with temperature, approximately as T(sup 5/2). Thus, cold mixtures of atoms and ions are expected to coexist for very long times, unlike room temperature mixtures of the same ion-atom combination. Thus, it seems feasible to cool ions via collisions with laser cooled atoms. Many of the conventional collisional interactions

  3. Improving IRMPD in a quadrupole ion trap.

    PubMed

    Newsome, G Asher; Glish, Gary L

    2009-06-01

    A focused laser is used to make infrared multiphoton photodissociation (IRMPD) more efficient in a quadrupole ion trap mass spectrometer. Efficient (up to 100%) dissociation at the standard operating pressure of 1 x 10(-3) Torr can be achieved without any supplemental ion activation and with shorter irradiation times. The axial amplitudes of trapped ion clouds are measured using laser tomography. Laser flux on the ion cloud is increased six times by focusing the laser so that the beam waist approximates the ion cloud size. Unmodified peptide ions from 200 Da to 3 kDa are completely dissociated in 2.5-10 ms at a bath gas pressure of 3.3 x 10(-4) Torr and in 3-25 ms at 1.0 x 10(-3) Torr. Sequential dissociation of product ions is increased by focusing the laser and by operating at an increased bath gas pressure to minimize the size of the ion cloud.

  4. Improved trapping and transport of cold atoms for magnetic microscopy

    NASA Astrophysics Data System (ADS)

    Gadge, Amruta; James, T.; Li, X.; Lu, Bo; Garridogonzalez, N.; Finke, A.; Mellor, C.; Fromhold, M.; Koller, C.; Orucevic, F.; Kruger, Peter

    2016-05-01

    Using cold atoms, a very sensitive and high resolution magnetic and electric field sensor can be realised. Ultra-close trapping of atoms would improve the resolution of cold-atom based surface probes. The limitation on the trapping distance arises from strongly distance-dependent effects such as Casimir force, Johnson noise etc. We are constructing an experimental system to trap atoms at surface separations of less than a micron. We will demonstrate the possibility of using special surfaces such as silicon nitride membranes and graphene for sub-micron trapping. We have designed a 10-layer printed circuit board, which can magnetically trap the cold atom cloud and transport it precisely to a desired location. This gives us the ability to study multiple samples within the same vacuum environment. In order to achieve higher atom number in the initial trapping stages, we use a dual-color MOT technique for Rb-87 atoms. Using this technique we achieve a significant increase in atom number and decrease in temperature. In this talk, I will present the results of the dual color MOT. I will also report on results related to magnetic transport and sub-micron trapping of atoms.

  5. A trapped mercury 199 ion frequency standard

    NASA Technical Reports Server (NTRS)

    Cutler, L. S.; Giffard, R. P.; Mcguire, M. D.

    1982-01-01

    Mercury 199 ions confined in an RF quadrupole trap and optically pumped by mercury 202 ion resonance light are investigated as the basis for a high performance frequency standard with commercial possibilities. Results achieved and estimates of the potential performance of such a standard are given.

  6. Thermalization of trapped ions: A quantum perturbation approach

    NASA Astrophysics Data System (ADS)

    Lamoreaux, S. K.

    1997-12-01

    The rate at which external random thermal fluctuations drive transitions between, and cause decoherence of, the near ground vibrational (harmonic oscillator) quantum states of trapped cold ions is of crucial importance in relation to quantum computing. Presented here is an estimate of these rates, for a single trapped ion, based on a quantum perturbation approach where an external thermal energy reservoir is electrically coupled to the ion. The results are for a general system, and it is shown that the relevant parameter in the interpretation of experimentally observed heating rates is the correlation time of the fluctuations. The rates due to the fluctuating electric field associated with blackbody radiation are also considered and shown to be negligible.

  7. Optical probing of cold trapped atoms

    NASA Technical Reports Server (NTRS)

    Fox, R. W.; Gilbert, S. L.; Hollberg, L.; Marquardt, J. H.; Robinson, H. G.

    1993-01-01

    Transitions between excited states of laser-cooled and laser-trapped rubidium and cesium atoms are probed by use of fiber and diode lasers. High-resolution Doppler-free spectra are detected by observation of the absorption and fluorescence of light from the intermediate level of two-step cascade systems. The optical double-resonance spectra show Autler-Townes splitting in the weak probe limit and more complicated spectra for a strongly coupled three-level system.

  8. Ion parking during ion/ion reactions in electrodynamic ion traps.

    PubMed

    McLuckey, Scott A; Reid, Gavin E; Wells, J Mitchell

    2002-01-15

    Under appropriate ion density conditions, it is possible to selectively inhibit rates of ion/ion reactions in a quadrupole ion trap via the application of oscillatory voltages to one or more electrodes of the ion trap. The phenomenon is demonstrated using dipolar resonance excitation applied to the end-cap electrodes of a three-dimensional quadrupole ion trap. The application of a resonance excitation voltage tuned to inhibit the ion/ion reaction rate of a specific range of ion mass-to-charge ratios is referred to as "ion parking". The bases for rate inhibition are (i) an increase in the relative velocity of the ion/ion reaction pair, which reduces the cross section for ion/ion capture and, at least in some cases, (ii) reduction in the time of physical overlap of positively charged and negatively charged ion clouds. The efficiency and specificity of the ion parking experiment is highly dependent upon ion densities, trapping conditions, ion charge states, and resonance excitation conditions. The ion parking experiment is illustrated herein along with applications to the concentration of ions originally present over a range of charge states into a selected charge state and in the selection of a particular ion from a set of ions derived from a simple protein mixture.

  9. Structure of the alkali-metal-atom + strontium molecular ions: Towards photoassociation and formation of cold molecular ions

    SciTech Connect

    Aymar, M.; Dulieu, O.; Guerout, R.

    2011-08-14

    The potential energy curves, permanent and transition dipole moments, and the static dipolar polarizability, of molecular ions composed of one alkali-metal atom and a strontium ion are determined with a quantum chemistry approach. The molecular ions are treated as effective two-electron systems and are treated using effective core potentials including core polarization, large gaussian basis sets, and full configuration interaction. In the perspective of upcoming experiments aiming at merging cold atom and cold ion traps, possible paths for radiative charge exchange, photoassociation of a cold lithium or rubidium atom and a strontium ion are discussed, as well as the formation of stable molecular ions.

  10. Trapped ion scaling with pulsed fast gates

    NASA Astrophysics Data System (ADS)

    Bentley, C. D. B.; Carvalho, A. R. R.; Hope, J. J.

    2015-10-01

    Fast entangling gates for trapped ion pairs offer vastly improved gate operation times relative to implemented gates, as well as approaches to trap scaling. Gates on a neighbouring ion pair only involve local ions when performed sufficiently fast, and we find that even a fast gate between a pair of distant ions with few degrees of freedom restores all the motional modes given more stringent gate speed conditions. We compare pulsed fast gate schemes, defined by a timescale faster than the trap period, and find that our proposed scheme has less stringent requirements on laser repetition rate for achieving arbitrary gate time targets and infidelities well below 10-4. By extending gate schemes to ion crystals, we explore the effect of ion number on gate fidelity for coupling two neighbouring ions in large crystals. Inter-ion distance determines the gate time, and a factor of five increase in repetition rate, or correspondingly the laser power, reduces the infidelity by almost two orders of magnitude. We also apply our fast gate scheme to entangle the first and last ions in a crystal. As the number of ions in the crystal increases, significant increases in the laser power are required to provide the short gate times corresponding to fidelity above 0.99.

  11. Trapping cold atoms using surface-grown carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Petrov, P. G.; Machluf, S.; Younis, S.; Macaluso, R.; David, T.; Hadad, B.; Japha, Y.; Keil, M.; Joselevich, E.; Folman, R.

    2009-04-01

    We present a feasibility study for loading cold atomic clouds into magnetic traps created by single-wall carbon nanotubes grown directly onto dielectric surfaces. We show that atoms may be captured for experimentally sustainable nanotube currents, generating trapped clouds whose densities and lifetimes are sufficient to enable detection by simple imaging methods. This opens the way for a different type of conductor to be used in atomchips, enabling atom trapping at submicron distances, with implications for both fundamental studies and for technological applications.

  12. Fundamental studies of ion injection and trapping of electrosprayed ions on a quadrupole ion trap mass spectrometer

    NASA Astrophysics Data System (ADS)

    Quarmby, Scott Thomas

    The quadrupole ion trap is a highly versatile and sensitive analytical mass spectrometer. Because of the advantages offered by the ion trap, there has been intense interest in coupling it to ionization techniques such as electrospray which form ions externally to the ion trap. In this work, experiments and computer simulations were employed to study the injection of electrosprayed ions into the ion trap of a Finnigan MAT LCQ LC/MS n mass spectrometer. The kinetic energy distribution of the ion beam was characterized and found to be relatively wide, a result of the high pressures from the atmospheric pressure source. One of the most important experimental parameters which affects ion injection efficiency is the RF voltage applied to the ring electrode. A theoretical model was fit to experimental data allowing the optimum RF voltage for trapping a given m/z ion to be predicted. Computer simulations of ion motion were performed to study the effect of various instrumental parameters on trapping efficiency. A commercially available ion optics program, SIMION v6.0, was chosen because it allowed the actual ion trap electrode geometry including endcap holes to be simulated. In contrast to previous computer simulations, SIMION provided the ability to start ions outside the ion trap and to simulate more accurately the injection of externally formed ions. The endcap holes were found to allow the RF field to penetrate out of the ion trap and affect ions as they approached the ion trap. From these simulations, a model for the process by which injected ions are trapped was developed. Using these computer simulations, techniques of improving trapping efficiency were investigated. Most previous techniques perturb ions which are already in the ion trap and therefore cannot be used to accumulate ions; the ability to accumulate ions is a necessity with ionization sources such as electrospray which form ions continuously. One such novel technique for improving trapping efficiency

  13. Extended linear ion trap frequency standard apparatus

    NASA Technical Reports Server (NTRS)

    Prestage, John D. (Inventor)

    1995-01-01

    A linear ion trap for frequency standard applications is provided with a plurality of trapping rods equally spaced and applied quadruple rf voltages for radial confinement of atomic ions and biased level pins at each end for axial confinement of the ions. The trapping rods are divided into two linear ion trap regions by a gap in each rod in a common radial plane to provide dc discontinuity, thus dc isolating one region from the other. A first region for ion-loading and preparation fluorescence is biased with a dc voltage to transport ions into a second region for resonance frequency comparison with a local oscillator derived frequency while the second region is held at zero voltage. The dc bias voltage of the regions is reversed for transporting the ions back into the first region for fluorescence measurement. The dual mode cycle is repeated continuously for comparison and feedback control of the local oscillator derived frequency. Only the second region requires magnetic shielding for the resonance function which is sensitive to any ambient magnetic fields.

  14. A toroidal trap for cold {}^{87}{Rb} atoms using an rf-dressed quadrupole trap

    NASA Astrophysics Data System (ADS)

    Chakraborty, A.; Mishra, S. R.; Ram, S. P.; Tiwari, S. K.; Rawat, H. S.

    2016-04-01

    We demonstrate the trapping of cold {}87{Rb} atoms in a toroidal geometry using a radio frequency (rf) dressed quadrupole magnetic trap formed by superposing a strong rf-field on a quadrupole trap. This rf-dressed quadrupole trap has the minimum potential away from the quadrupole trap centre on a circular path which facilitates trapping in toroidal geometry. In these experiments, the laser cooled atoms were first trapped in a quadrupole trap, then cooled evaporatively using a weak rf-field, and finally trapped in an rf-dressed quadrupole trap. The radius of the toroid could be varied by varying the frequency of the dressing rf-field. It has also been demonstrated that a single rf source and an antenna can be used for the rf-evaporative cooling as well as for the rf-dressing of atoms. The atoms trapped in the toroidal trap may have applications in the realization of an atom gyroscope as well as in studying the quantum gases in low dimensions.

  15. Trapping cold molecules and atoms: Simultaneous magnetic deceleration and trapping of cold molecular Oxygen with Lithium atoms

    NASA Astrophysics Data System (ADS)

    Akerman, Nitzan; Karpov, Michael; Segev, Yair; Bibelink, Natan; Narevicius, Julia; Narevicius, Edvardas

    2016-05-01

    Cooling molecules to the ultra-cold regime remains a major challenge in the growing field of cold molecules. The molecular internal degrees of freedom complicate the effort of direct application of laser cooling. An alternative and general path towards ultra-cold molecules relies on sympathetic cooling via collisions with laser-cooled atoms. Here, we demonstrate the first step towards application of sympathetic cooling by co-trapping of molecular Oxygen with Lithium atoms in a magnetic trap at a temperature of 300 mK. Our experiment begins with a pulsed supersonic beam which is a general source for cold high-flux atomic and molecular beams. Although the supersonic expansion efficiently cools the beam to temperatures below 1K, it also accelerates the beam to high mean velocities. We decelerate a beam of O2 in a moving magnetic trap decelerator from 375 m/s to a stop. We entrained the molecular beam with Li atoms by laser ablation prior to deceleration. The deceleration ends with loading the molecules and atoms into a static quadrupole trap, which is generated by two permanent magnets. We estimate 109 trapped molecules with background limited lifetime of 0.6 Sec. Our achievement enables application of laser cooling on the Li atoms in order to sympathetically cool the O2.

  16. Ion cloud model for a linear quadrupole ion trap.

    PubMed

    Douglas, Don J; Konenkov, Nikolai V

    2012-01-01

    If large numbers of ions are stored in a linear quadrupole ion trap, space charge causes the oscillation frequencies of ions to decrease. Ions then appear at higher apparent masses when resonantly ejected for mass analysis. In principle, to calculate mass shifts requires calculating the positions of all ions, interacting with each other, at all times, with a self-consistent space charge field. Here, we propose a simpler model for the ion cloud in the case where mass shifts and frequency shifts are relatively small (ca 0.2% and 0.4%, respectively), the trapping field is much stronger (ca × 10(2)) than the space charge field and space charge only causes small perturbations to the ion motion. The self-consistent field problem need not be considered. As test ions move with times long compared to a cycle of the trapping field, the motion of individual ions can be ignored. Static positions of the ions in the cloud are used. To generate an ion cloud, trajectories of N (ca 10,000) ions are calculated for random times between 10 and 100 cycles of the trapping radio frequency field. The ions are then distributed axially randomly in a trap four times the field radius, r(0) in length. The potential and electric field from the ion cloud are calculated from the ion positions. Near the trap center (distances r< 1r(0)), the potential and electric fields from space charge are not cylindrically symmetric, but are quite symmetric for greater values of r. Trajectories of test ions, oscillation frequencies and mass shifts can then be calculated in the trapping field, including the space charge field. Mass shifts are in good agreement with experiments for reasonable values of the initial positions and speeds of the ions. Agreement with earlier analytical models for the ion cloud, based on a uniform occupation of phase space, or a thermal (Boltzmann) distribution of ions trapped in the effective potential [D. Douglas and N.V. Konenkov, Rapid Commun. Mass Spectrom. 26, 2105 (2012)] is

  17. Ion trapping and separation using potential wells

    SciTech Connect

    Butler, M.A.

    2000-01-04

    A new mode of operation for an ion mobility spectrometer (IMS) has been demonstrated that uses potential wells to trap and separate ions by their mobility. This mode of operation has been made feasible by the improvements in personal computers that now allow real-time control of the potentials on ring electrodes in the IMS drift tube. This mode of operation does not require a shutter grid and allows the accumulation of ions in the potential well to enhance the ion signal. Loss of ions from the potential well is controlled by the radial electric fields required by Gauss's law.

  18. Cryogenically cooled octupole ion trap for spectroscopy of biomolecular ions.

    PubMed

    Boyarkin, Oleg V; Kopysov, Vladimir

    2014-03-01

    We present here the design of a linear octupole ion trap, suitable for collisional cryogenic cooling and spectroscopy of large ions. The performance of this trap has been assessed using ultraviolet (UV) photofragmentation spectroscopy of protonated dipeptides. At the trap temperature of 6.1 K, the vibrational temperature of the ions reaches 9.1 K, although their estimated translational temperature is ~150 K. This observation suggests that, despite the significant translational heating by radio-frequency electrical field, vibrational cooling of heavy ions in the octupole is at least as efficient as in the 22-pole ion traps previously used in our laboratory. In contrast to the 22-pole traps, excellent radial confinement of ions in the octupole makes it convenient for laser spectroscopy and boosts the dissociation yield of the stored ions to 30%. Overlap of the entire ion cloud by the laser beam in the octupole also allows for efficient UV depletion spectroscopy of ion-He clusters. The measured electronic spectra of the dipeptides and the clusters differ drastically, complicating a use of UV tagging spectroscopy for structural determination of large species.

  19. Cryogenically cooled octupole ion trap for spectroscopy of biomolecular ions

    NASA Astrophysics Data System (ADS)

    Boyarkin, Oleg V.; Kopysov, Vladimir

    2014-03-01

    We present here the design of a linear octupole ion trap, suitable for collisional cryogenic cooling and spectroscopy of large ions. The performance of this trap has been assessed using ultraviolet (UV) photofragmentation spectroscopy of protonated dipeptides. At the trap temperature of 6.1 K, the vibrational temperature of the ions reaches 9.1 K, although their estimated translational temperature is ˜150 K. This observation suggests that, despite the significant translational heating by radio-frequency electrical field, vibrational cooling of heavy ions in the octupole is at least as efficient as in the 22-pole ion traps previously used in our laboratory. In contrast to the 22-pole traps, excellent radial confinement of ions in the octupole makes it convenient for laser spectroscopy and boosts the dissociation yield of the stored ions to 30%. Overlap of the entire ion cloud by the laser beam in the octupole also allows for efficient UV depletion spectroscopy of ion-He clusters. The measured electronic spectra of the dipeptides and the clusters differ drastically, complicating a use of UV tagging spectroscopy for structural determination of large species.

  20. Synthesis of cold antihydrogen in a cusp trap.

    PubMed

    Enomoto, Y; Kuroda, N; Michishio, K; Kim, C H; Higaki, H; Nagata, Y; Kanai, Y; Torii, H A; Corradini, M; Leali, M; Lodi-Rizzini, E; Mascagna, V; Venturelli, L; Zurlo, N; Fujii, K; Ohtsuka, M; Tanaka, K; Imao, H; Nagashima, Y; Matsuda, Y; Juhász, B; Mohri, A; Yamazaki, Y

    2010-12-10

    We report here the first successful synthesis of cold antihydrogen atoms employing a cusp trap, which consists of a superconducting anti-Helmholtz coil and a stack of multiple ring electrodes. This success opens a new path to make a stringent test of the CPT symmetry via high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atoms.

  1. Synthesis of Cold Antihydrogen in a Cusp Trap

    SciTech Connect

    Enomoto, Y.; Nagata, Y.; Kanai, Y.; Mohri, A.; Kuroda, N.; Kim, C. H.; Torii, H. A.; Fujii, K.; Ohtsuka, M.; Tanaka, K.; Matsuda, Y.; Michishio, K.; Nagashima, Y.; Higaki, H.; Corradini, M.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Venturelli, L.; Zurlo, N.

    2010-12-10

    We report here the first successful synthesis of cold antihydrogen atoms employing a cusp trap, which consists of a superconducting anti-Helmholtz coil and a stack of multiple ring electrodes. This success opens a new path to make a stringent test of the CPT symmetry via high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atoms.

  2. Motional-mode analysis of trapped ions

    NASA Astrophysics Data System (ADS)

    Kalis, Henning; Hakelberg, Frederick; Wittemer, Matthias; Mielenz, Manuel; Warring, Ulrich; Schaetz, Tobias

    2016-08-01

    We present two methods for characterization of motional-mode configurations that are generally applicable to the weak- and strong-binding limit of single or multiple trapped atomic ions. Our methods are essential to realize control of the individual as well as the common motional degrees of freedom. In particular, when implementing scalable radio-frequency trap architectures with decreasing ion-electrode distances, local curvatures of electric potentials need to be measured and adjusted precisely, e.g., to tune phonon tunneling and control effective spin-spin interaction. We demonstrate both methods using single 25Mg+ ions that are individually confined 40 μ m above a surface-electrode trap array and prepared close to the ground state of motion in three dimensions.

  3. Product ion scanning using a Q-q-Q linear ion trap (Q TRAP) mass spectrometer.

    PubMed

    Hager, James W; Yves Le Blanc, J C

    2003-01-01

    The use of a Q-q-Q(linear ion trap) instrument to obtain product ion spectra is described. The instrument is based on the ion path of a triple quadrupole mass spectrometer with Q3 operable as either a conventional RF/DC quadrupole mass filter or a linear ion trap mass spectrometer with axial ion ejection. This unique ion optical arrangement allows de-coupling of precursor ion isolation and fragmentation from the ion trap itself. The result is a high sensitivity tandem mass spectrometer with triple quadrupole fragmentation patterns and no inherent low mass cut-off. The use of the entrance RF-only section of the instrument as accumulation ion trap while the linear ion trap mass spectrometer is scanning enhances duty cycles and results in increased sensitivities by as much as a factor of 20. The instrument is also capable of all of the triple quadrupole scans including multiple-reaction monitoring (MRM) as well as precursor and constant neutral loss scanning. The high product ion scanning sensitivity allows the recording of useful product ion spectra near the MRM limit of quantitation.

  4. Small Scale Cold Traps on Airless Planetary Bodies

    NASA Astrophysics Data System (ADS)

    Hayne, Paul O.; Aharonson, O.; Williams, J.; Siegler, M. A.; Greenhagen, B. T.; Bandfield, J.; Vasavada, A. R.; Paige, D. A.; Diviner Lunar Radiometer Science Team

    2013-10-01

    Lacking an atmosphere to transport heat, temperatures on airless bodies are primarily controlled by latitude and local time. However, local topography strongly affects temperatures at the surface and in the subsurface by changing the intensity and timing of insolation. In the case of low-obliquity bodies such as Mercury and the Earth’s moon, topography near the poles casts perennial shadows where volatiles such as water ice may be cold-trapped for billions of years. Prior studies have focused primarily on large contiguous cold traps > 1 km resolvable by instruments in lunar orbit. In this investigation, we used infrared measurements of the Moon, thermal models, and a statistical rough surface model to show that such cold traps may exist on a vast range of scales, from the largest impact craters, down to the skin depth of the diurnal temperature oscillation. The extremely insulating nature of planetary regolith leads to extreme temperature gradients and shallow diurnal skin depths. For example, the lunar 29-day diurnal temperature oscillation is damped to ~1% at a depth of 0.5 m. Therefore, at latitudes > 60° where perennial shadow exists, cold traps as small as a few tens of centimeters could exist. As two test cases, we calculated the fractional surface areas on the Moon (obliquity = 1.6°) and Ceres (3-5°) where temperatures remain < 110 K all year round, such that water ice is thermally stable at the surface for billions of years. We also calculated fractional areas where subsurface temperatures are < 145 K, such that subsurface ice deposits are stable on similar timescales. Finally, we will discuss the implications of these proposed small-scale cold traps for other airless bodies, including asteroids and giant planet satellites.

  5. Trapping and evolution dynamics of strongly magnetized cold gases

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hoon

    Cold Rydberg atoms and ultracold plasmas have been studied in the strong-magnetization regime. In this new territory, novel atomic and plasma states---such as guiding-center drift Rydberg attains and strongly magnetized, quasi-neutral, ultracold plasmas---have been created and investigated. The evolution dynamics studies of these exotic diamagnetic forms of matter, made possible by implementing a superconducting magnetic atom trap, revealed rich dynamical features in the systems: The Landau-quantized energy structure has led to entirely different evolutions of the highly excited atoms in laser-excited or drift Rydberg states than in magnetic-field-free cases; and the presence of the strong magnetic field has drastically altered the collisional behavior and expansion dynamics of the plasmas. Furthermore, atom cooling and trapping methodology has been extended in multiple directions. Firstly, laser cooling and magnetic trapping of ground-state atoms has been demonstrated in magnetic; fields exceeding 3 Tesla, representing a 20-fold increase in the field-strength of cold-atom traps. Secondly, the trapping of Rydberg atoms with a lifetime of 80 ms has been achieved. This trapping technique exploits the quasi-free nature of Rydberg electrons, which can be adopted in other forms of Rydberg-atom trapping. Lastly; the trapping of two-component, ultracold plasmas has been demonstrated in a nested Penning-trap configuration. The confinement of quasi-neutral ultracold plasmas allowed us to observe novel effects such as the correlation between the ionic oscillation and the electron energy distribution.

  6. Electron beam ion source and electron beam ion trap (invited)

    SciTech Connect

    Becker, Reinard; Kester, Oliver

    2010-02-15

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not ''sorcery'' but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  7. Quantum computation with ions in microscopic traps

    NASA Astrophysics Data System (ADS)

    Šašura, Marek; Steane, Andrew M.

    2002-12-01

    We discuss a possible experimental realization of fast quantum gates with high fidelity with ions confined in microscopic traps. The original proposal of this physical system for quantum computation comes from Cirac and Zoller (Nature 404, 579 (2000)). In this paper we analyse a sensitivity of the ion-trap quantum gate on various experimental parameters which was omitted in the original proposal. We address imprecision of laser pulses, impact of photon scattering, nonzero temperature effects and influence of laser intensity fluctuations on the total fidelity of the two-qubit phase gate.

  8. Interaction of field-aligned cold plasma flows with an equatorially-trapped hot plasma - Electrostatic shock formation

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra

    1993-01-01

    Effects of equatorially trapped hot plasma on the highly supersonic cold-plasma flow occurring during early stage plasmaspheric refilling are studied by means of numerical simulations. It is shown that the equatorially trapped hot ions set up a potential barrier for the cold ion beams and facilitate formation of electrostatic shocks by reflecting them from the equatorial region. Simulations with and without the hot plasma show different flow properties; the formation of electrostatic shocks occur only in the former case. The simulation with the hot plasma also reveals that the magnetic trapping in conjunction with the evolution of the electrostatic potential barrier produces ion velocity distribution functions consisting of a cold core and a hot ring in the perpendicular velocity. Such a distribution function provides a source of free energy for equatorial waves. The corresponding electron population is warm and field-aligned.

  9. Trapped Atomic Ions and Quantum Information Processing

    SciTech Connect

    Wineland, D. J.; Leibfried, D.; Bergquist, J. C.; Blakestad, R. B.; Bollinger, J. J.; Britton, J.; Chiaverini, J.; Epstein, R. J.; Hume, D. B.; Itano, W. M.; Jost, J. D.; Koelemeij, J. C. J.; Langer, C.; Ozeri, R.; Reichle, R.; Rosenband, T.; Schaetz, T.; Schmidt, P. O.; Seidelin, S.; Shiga, N.

    2006-11-07

    The basic requirements for quantum computing and quantum simulation (single- and multi-qubit gates, long memory times, etc.) have been demonstrated in separate experiments on trapped ions. Construction of a large-scale information processor will require synthesis of these elements and implementation of high-fidelity operations on a very large number of qubits. This is still well in the future. NIST and other groups are addressing part of the scaling issue by trying to fabricate multi-zone arrays of traps that would allow highly-parallel and scalable processing. In the near term, some simple quantum processing protocols are being used to aid in quantum metrology, such as in atomic clocks. As the number of qubits increases, Schroedinger's cat paradox and the measurement problem in quantum mechanics become more apparent; with luck, trapped ion systems might be able to shed light on these fundamental issues.

  10. Ion Behavior in an Electrically Compensated Ion Cyclotron Resonance Trap

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We recently described a new electrically compensated trap in FT ion cyclotron resonance mass spectrometry and developed a means of tuning traps of this general design. Here, we describe a continuation of that research by comparing the ion transient lifetimes and the resulting mass resolving powers and signal-to-noise (S/N) ratios that are achievable in the compensated vs. uncompensated modes of this trap. Transient lifetimes are ten times longer under the same conditions of pressure, providing improved mass resolving power and S/N ratios. The mass resolving power as a function of m/z is linear (log-log plot) and nearly equal to the theoretical maximum. Importantly, the ion cyclotron frequency as a function of ion number decreases linearly in accord with theory, unlike its behavior in the uncompensated mode. This linearity should lead to better control in mass calibration and increased mass accuracy than achievable in the uncompensated mode. PMID:21499521

  11. Low temperature cold trapping of uranium hexafluoride containing hydrogen fluoride

    SciTech Connect

    Hobbs, W.E.; Barber, E.J.; Jones, C.G.

    1990-10-01

    The use of a freezer-sublimer system operating at low desublimation pressures to replace 10-in. nuclearly safe cold traps for low assay (<5% U-235) uranium hexafluoride (UF{sub 6}) would significantly simplify operations and is economically attractive provided the nuclear safety of the system can be assured. A major requirement of such assurance is the availability of conditions guaranteeing that the nuclear safety design criterion, which requires that the H/U atomic ratio in the condensate in the freezer-sublimer always be less than 0.33 for assays up to 5%, will never be violated. A general vapor pressure equation giving the vapor pressure of HF-UF{sub 6} solutions as a function of temperature and mole fraction UF{sub 6} has been developed. The precision of the data at the 95% confidence level is {plus minus}0.1 torr at temperatures between {minus}100{degree}F and {minus}121{degree}F. The calculated vapor pressure of pure HF is 4.6 torr at {minus}100{degree}F and 3.1 torr at {minus}108{degree}F. Theoretical considerations suggest that the true value will be slightly lower. In experimental studies of the cold trapping operation at {minus}108{degree}F and at a trap pressure of 2.2 torr, only 7.3% of the HF entering the trap was retained in the trap. At a trap pressure of 4.6 torr, over 80% of the HF entering the trap was retained. The data obtained in this study confirms that the physical chemistry of the HF-UF{sub 6} system previously developed accurately describes the behavior of the system and that so long as the pressure in the trap is maintained below the vapor pressure of pure HF at the trap temperatures, there is no way that sufficient HF can be trapped to give an H/U ratio of 0.33 regardless of the HF/UF{sub 6} ratio in the feed to the trap. 5 refs., 4 tabs.

  12. Trapped Ion Magnetic Resonance: Concepts and Designs

    NASA Astrophysics Data System (ADS)

    Pizarro, Pedro Jose

    A novel spectroscopy of trapped ions is proposed which will bring single-ion detection sensitivity to the observation of magnetic resonance spectra and resolve the apparent incompatibility in existing techniques between high information content and high sensitivity. Methods for studying both electron spin resonance (ESR) and nuclear magnetic resonance (NMR) are designed. They assume established techniques for trapping ions in high magnetic field and observing electrically the trapping frequencies with high resolution (<1 Hz) and sensitivity (single -ion). A magnetic bottle field gradient couples the spin and spatial motions together and leads to the small spin -dependent force on the ion exploited by Dehmelt to observe directly the perturbation of the ground-state electron's axial frequency by its spin magnetic moment. A series of fundamental innovations is described to extend magnetic resonance to molecular ions ( cong 100 amu) and nuclear magnetic moments. It is demonstrated how time-domain trapping frequency observations before and after magnetic resonance can be used to make cooling of the particle to its ground state unnecessary. Adiabatic cycling of the magnetic bottle off between detection periods is shown to be practical and to allow high-resolution magnetic resonance to be encoded pointwise as the presence or absence of trapping frequency shifts. Methods of inducing spin -dependent work on the ion orbits with magnetic field gradients and Larmor frequency irradiation are proposed which greatly amplify the attainable shifts in trapping frequency. The first proposal presented builds on Dehmelt's experiment to reveal ESR spectra. A more powerful technique for ESR is then designed where axially synchronized spin transitions perform spin-dependent work in the presence of a magnetic bottle, which also converts axial amplitude changes into cyclotron frequency shifts. The most general approach presented is a continuous Stern-Gerlach effect in which a magnetic field

  13. Linear ion trap based atomic frequency standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. J.; Maleki, Lute

    1991-01-01

    In order to develop a trapped ion-based fieldable frequency standard with stability 1 x 10 to the -13th/sq rt tau for averaging times tau greater than 10,000 s, a hybrid RF/DC linear ion trap was developed which permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. The authors have confined Hg-199(+) ions in this trap and have measured very high Q transitions with good SNRs. In preliminary measurements they obtained stabilities of 1.6 x 10 to the -13th/sq rt tau (tau between 50 and 800 s) with a 160-mHz wide atomic resonance linewidth and a signal-to-noise ratio of 40 for each measurement cycle. Atomic resonance lines as narrow as 30 mHz on the 40.5-GHz clock transition have been measured with no appreciable reduction in the ion signal. A stability of 7 x 10 to the -14th/sq rt tau is made possible by the signal-to-noise and line Q of this measured transition. Analysis of fundamental sources of frequency instability indicates that a long-term stability of 2 x 10 to the -16th is feasible for this device with existing technology for tau = 10 to the 6th s or more.

  14. Miniaturized Linear Wire Ion Trap Mass Analyzer.

    PubMed

    Wu, Qinghao; Li, Ailin; Tian, Yuan; Zare, Richard N; Austin, Daniel E

    2016-08-01

    We report a linear ion trap (LIT) in which the electric field is formed by fine wires held under tension and accurately positioned using holes drilled in two end plates made of plastic. The coordinates of the hole positions were optimized in simulation. The stability diagram and mass spectra using boundary ejection were compared between simulation and experiment and good agreement was found. The mass spectra from experiments show peak widths (fwhm) in units of mass-to-charge of around 0.38 Th using a scan rate of 3830 Th/s. The limits of detection are 137 ppbv and 401 ppbv for benzene and toluene, respectively. Different sizes of the wire ion trap can be easily fabricated by drilling holes in scaled positions. Other distinguishing features, such as high ion and photon transmission, low capacitance, high tolerance to mechanical and assembly error, and low weight, are discussed. PMID:27373557

  15. The trapped mercury ion frequency standard

    NASA Technical Reports Server (NTRS)

    Mcguire, M. D.

    1977-01-01

    Singly ionized mercury atoms have a structure similar to neutral alkali atoms. They can be maintained as ions for very long times in an RF quadrupole ion trap. Thus, their ground state hyperfine structure can be used to make a frequency standard using optical pumping techniques similar to the well-known rubidium standard. The mass 199 isotope of mercury has an ionic hyperfine structure of 40.5 GHz. In a trap system a linewidth of 10 Hz has been measured. An expression is presented for the short-term stability of a proposed mercury standard as set by the achieved signal to noise ratio. There is prospect of further improvement. Long-term stability is affected by second order doppler effect, and by pressure, light, and Stark shifts. However, these appear either sufficiently small or sufficiently controlable that the proposed mercury ion standard would be competitive with existing standards.

  16. Development of a Kingdon ion trap system for trapping externally injected highly charged ions

    SciTech Connect

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar{sup q+} (q = 5–7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar{sup q+} (q = 5–7) under a constant number density of H₂ and determined the charge-transfer cross sections of Ar{sup q+}(q = 5, 6)-H₂ collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula.

  17. Experiments with Single Trapped Ytterbium Ions at JPL

    NASA Technical Reports Server (NTRS)

    Yu, Nan; Maleki, Lute

    2000-01-01

    This paper presents viewgraphs of experiments performed with single trapped Ytterbium ions. The topics include: 1) Ytterbium ion level scheme; 2) Paul-Straubel rf trap and single ion image; 3) D5/2 state lifetime measurement; 4) D3/2 state lifetime measurement; 5) Trapped individual ions in an optical cavity; 6) Initial exploratory system: experimental goals; and 7) Future systems: trap-cavity integration II.

  18. The JPL trapped mercury ion frequency standard

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Dick, G. J.; Maleki, L.

    1988-01-01

    In order to provide frequency standards for the Deep Space Network (DSN) which are more stable than present-day hydrogen masers, a research task was established under the Advanced Systems Program of the TDA to develop a Hg-199(+) trapped ion frequency standard. The first closed-loop operation of this kind is described. Mercury-199 ions are confined in an RF trap and are state-selected through the use of optical pumping with 194 nm UV light from a Hg-202 discharge lamp. Absorption of microwave radiation at the hyperfine frequency (40.5 GHz) is signaled by atomic fluorescence of the UV light. The frequency of a 40.5 GHz oscillator is locked to a 1.6 Hz wide atomic absorption line of the trapped ions. The measured Allan variance of this locked oscillator is currently gamma sub y (pi) = 4.4 x 10 to the minus 12th/square root of pi for 20 is less than pi is less than 320 seconds, which is better stability than the best commercial cesium standards by almost a factor of 2. This initial result was achieved without magnetic shielding and without regulation of ion number.

  19. Quantum error correction with trapped ions

    NASA Astrophysics Data System (ADS)

    Schindler, Philipp

    Quantum computers promise exponential speed-up compared to their classical counterparts for certain problems. Unfortunately, the states required for quantum computation are fragile and lose their quantum properties with growing system size. In a milestone work, it has been shown that quantum error correction can overcome this problem and enable arbitrary long and arbitrary high quality quantum algorithms. However, current experiments are not able to fulfill the requirements to employ useful quantum error correction procedures. In this talk, I will first review past proof-of-principle experiments in trapped ion quantum information processors. Building on that, I will sketch a way towards a medium-sized trapped ion system that will be capable of running an error correction procedure that outperforms it constituents.

  20. Quantum Rabi Model with Trapped Ions.

    PubMed

    Pedernales, J S; Lizuain, I; Felicetti, S; Romero, G; Lamata, L; Solano, E

    2015-01-01

    We propose the quantum simulation of the quantum Rabi model in all parameter regimes by means of detuned bichromatic sideband excitations of a single trapped ion. We show that current setups can reproduce, in particular, the ultrastrong and deep strong coupling regimes of such a paradigmatic light-matter interaction. Furthermore, associated with these extreme dipolar regimes, we study the controlled generation and detection of their entangled ground states by means of adiabatic methods. Ion traps have arguably performed the first quantum simulation of the Jaynes-Cummings model, a restricted regime of the quantum Rabi model where the rotating-wave approximation holds. We show that one can go beyond and experimentally investigate the quantum simulation of coupling regimes of the quantum Rabi model that are difficult to achieve with natural dipolar interactions. PMID:26482660

  1. Ultrafast Interferometry and Gates with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Johnson, Kale; Wong-Campos, David; Neyenhuis, Brian; Mizrahi, Jonathan; Monroe, Christopher

    2016-05-01

    We sense the motion of a trapped atomic ion using a sequence of state-dependent ultrafast momentum kicks. We use this atom interferometer to characterize a nearly-pure quantum state with n = 1 phonon and accurately measure thermal states ranging from near the zero-point energy to n ~104 , with the possibility of extending at least 100 times higher in energy. The complete energy range of this method spans from the ground state to far outside of the Lamb-Dicke regime, where atomic motion is greater than the optical wavelength. Apart from thermometry, these interferometric techniques are useful for quantum information purposes, and we discuss the outlook for ultrafast entangling gates between multiple trapped ions. This work is supported by the NSF Physics Frontier Center at JQI.

  2. Trapped Ion Quantum Computation by Adiabatic Passage

    SciTech Connect

    Feng Xuni; Wu Chunfeng; Lai, C. H.; Oh, C. H.

    2008-11-07

    We propose a new universal quantum computation scheme for trapped ions in thermal motion via the technique of adiabatic passage, which incorporates the advantages of both the adiabatic passage and the model of trapped ions in thermal motion. Our scheme is immune from the decoherence due to spontaneous emission from excited states as the system in our scheme evolves along a dark state. In our scheme the vibrational degrees of freedom are not required to be cooled to their ground states because they are only virtually excited. It is shown that the fidelity of the resultant gate operation is still high even when the magnitude of the effective Rabi frequency moderately deviates from the desired value.

  3. Quantum Rabi Model with Trapped Ions

    PubMed Central

    Pedernales, J. S.; Lizuain, I.; Felicetti, S.; Romero, G.; Lamata, L.; Solano, E.

    2015-01-01

    We propose the quantum simulation of the quantum Rabi model in all parameter regimes by means of detuned bichromatic sideband excitations of a single trapped ion. We show that current setups can reproduce, in particular, the ultrastrong and deep strong coupling regimes of such a paradigmatic light-matter interaction. Furthermore, associated with these extreme dipolar regimes, we study the controlled generation and detection of their entangled ground states by means of adiabatic methods. Ion traps have arguably performed the first quantum simulation of the Jaynes-Cummings model, a restricted regime of the quantum Rabi model where the rotating-wave approximation holds. We show that one can go beyond and experimentally investigate the quantum simulation of coupling regimes of the quantum Rabi model that are difficult to achieve with natural dipolar interactions. PMID:26482660

  4. Note: Ion source design for ion trap systems

    NASA Astrophysics Data System (ADS)

    Noriega, J. R.; Quevedo, M.; Gnade, B.; Vasselli, J.

    2013-06-01

    A small plasma (glow discharge) based ion source and circuit are described in this work. The ion source works by producing a high voltage pulsed discharge between two electrodes in a pressure range of 50-100 mTorr. A third mesh electrode is used for ion extraction. The electrodes are small stainless steel screws mounted in a MACOR ionization chamber in a linear arrangement. The electrode arrangement is driven by a circuit, design for low power operation. This design is a proof of concept intended for applications on small cylindrical ion traps.

  5. An improved linear ion trap physics package

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.

    1993-01-01

    This article describes an improvement in the architecture of the physics package used in the Linear Ion Trap (LIT)-based frequency standard recently developed at JPL. This new design is based on the observation that ions can be moved along the axis of an LIT by applied dc voltages. The state selection and interrogation region can be separated from the more critical microwave resonance region where the multiplied local oscillator signal is compared with the stable atomic transition. This separation relaxes many of the design constraints of the present units. Improvements include increased frequency stability and a substantial reduction in size, mass, and cost of the final frequency standard.

  6. Quantum computation with ``hot`` trapped ions

    SciTech Connect

    James, D.F.V.; Schneider, S. |; Milburn, G.J.

    1998-12-31

    The authors describe two methods that have been proposed to circumvent the problem of heating by external electromagnetic fields in ion trap quantum computers. Firstly the higher order modes of ion oscillation (i.e., modes other than the center-of-mass mode) have much slower heating rates, and can therefore be employed as a reliable quantum information bus. Secondly they discuss a recently proposed method combining adiabatic passage and a number-state dependent phase shift which allows quantum gates to be performed using the center-of-mass mode as the information bus, regardless of its initial state.

  7. Spectroscopy of ions using fast beams and ion traps

    SciTech Connect

    Pinnington, E H; Trabert, E

    2004-10-01

    A knowledge of the spectra of ionized atoms is of importance in many fields. They can be studied in a wide variety of light sources. In recent years techniques coming under the broad heatings of fast beams and ion traps have been used extensively for such investigations. This article considers the advantages that various techniques have for particular applications.

  8. Resonance of the Macromotion of Ions Trapped in a RF Trap by the Subharmonic Oscillation

    NASA Astrophysics Data System (ADS)

    Yoda, Jun; Sugiyama, Kazuhiko

    1992-11-01

    Yb+ ions were trapped in an uncompensated rf trap with light buffer gas and then the storage time, as well as the total number of the trapped ions, was determined by the rf resonance method. When the ratio of the frequency of the trapping field to that of the macromotion of the trapped ions was an integer, the total number and the storage time were smaller and shorter, respectively, than those obtained when the ratio was a half-integer. A theoretical calculation shows that this effect, called the subharmonic oscillation, is caused by excitation of the macromotion of the trapped ions by the leaked trapping rf field, in the case in which the ion trap has an octupole besides a quadrupole potential.

  9. Progress Toward a Cold Ion Interferometer

    NASA Astrophysics Data System (ADS)

    Archibald, James; Christopher, Erickson; Jackson, Jarom; Durfee, Dallin

    2012-06-01

    We describe progress on a cold ion matter-wave interferometer. The ions are generated by laser-cooling strontium and then photo-ionizing the atoms with a two-photon transition to an auto- ionizing state in the continuum. Each ion's quantum wave will be split and recombined using stimulated Raman transitions between the hyperfine ground states of Sr^87+. The interferometer phase will be determined by measuring the fraction of ions exiting in each hyperfine state. We will discuss the theory of operation, experimental methods, and potential applications of the device.

  10. Prospects for quantum computation with trapped ions

    SciTech Connect

    Hughes, R.J.; James, D.F.V.

    1997-12-31

    Over the past decade information theory has been generalized to allow binary data to be represented by two-state quantum mechanical systems. (A single two-level system has come to be known as a qubit in this context.) The additional freedom introduced into information physics with quantum systems has opened up a variety of capabilities that go well beyond those of conventional information. For example, quantum cryptography allows two parties to generate a secret key even in the presence of eavesdropping. But perhaps the most remarkable capabilities have been predicted in the field of quantum computation. Here, a brief survey of the requirements for quantum computational hardware, and an overview of the in trap quantum computation project at Los Alamos are presented. The physical limitations to quantum computation with trapped ions are discussed.

  11. Trapped Ion Quantum Computing with Microwaves

    NASA Astrophysics Data System (ADS)

    Randall, Joe; Weidt, Sebastian; Standing, Eamon; Webster, Simon; Lake, Kim; Murgia, David; Navickas, Tomas; Lekitsch, Bjoern; Hughes, Marcus; Sterling, Robin; de Motte, Darren; Giri, Gouri; Rodriguez, Andrea; Webb, Anna; Rattanasonti, Hwanjit; Srinivasan, Prasanna; Kraft, Michael; Maclean, Jessica; Mellor, Chris; Hensinger, Winfried

    2015-03-01

    To this point, entanglement operations in trapped ion qubits have been predominantly performed with lasers. However, this becomes problematic when scaling to large numbers of qubits due to the challenging engineering required. The use of stable and easily controllable microwaves to drive entanglement gates can overcome this problem. We will present our work towards implementing multi-qubit entanglement gates using microwaves in an experimental setup that produces a static magnetic field gradient of 24 T/m over an ion string. We will first present a scheme for preparing and manipulating dressed-state qubits and qutrits that are highly robust to decoherence from magnetic field fluctuations. We will also present our work experimentally demonstrating motional sideband transitions and Schrödinger cat states using microwaves in conjunction with the magnetic field gradient, as well as sideband cooling to the ground state of motion using dressed-states. Furthermore, we will show our latest results in creating microfabricated ion trap chips towards large scale quantum computing and simulation.

  12. Ball-grid array architecture for microfabricated ion traps

    NASA Astrophysics Data System (ADS)

    Guise, Nicholas D.; Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-01

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with 40Ca+ ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with 171Yb+ ions in a second BGA trap.

  13. Ball-grid array architecture for microfabricated ion traps

    SciTech Connect

    Guise, Nicholas D. Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-07

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with {sup 40}Ca{sup +} ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with {sup 171}Yb{sup +} ions in a second BGA trap.

  14. Space charge induced nonlinear effects in quadrupole ion traps.

    PubMed

    Guo, Dan; Wang, Yuzhuo; Xiong, Xingchuang; Zhang, Hua; Zhang, Xiaohua; Yuan, Tao; Fang, Xiang; Xu, Wei

    2014-03-01

    A theoretical method was proposed in this work to study space charge effects in quadrupole ion traps, including ion trapping, ion motion frequency shift, and nonlinear effects on ion trajectories. The spatial distributions of ion clouds within quadrupole ion traps were first modeled for both 3D and linear ion traps. It is found that the electric field generated by space charge can be expressed as a summation of even-order fields, such as quadrupole field, octopole field, etc. Ion trajectories were then solved using the harmonic balance method. Similar to high-order field effects, space charge will result in an "ocean wave" shape nonlinear resonance curve for an ion under a dipolar excitation. However, the nonlinear resonance curve will be totally shifted to lower frequencies and bend towards ion secular frequency as ion motion amplitude increases, which is just the opposite effect of any even-order field. Based on theoretical derivations, methods to reduce space charge effects were proposed.

  15. Progress Towards Quantum Simulation Using Micro-fabricated Ion Traps

    NASA Astrophysics Data System (ADS)

    Wright, K.; Ji, G.; Rickerd, C.; Collins, K.; Monroe, C.

    2015-05-01

    We report on current experimental progress towards using a surface electrode trap for quantum simulation. We use a micro-fabricated trap developed collaboratively between the Georgia Tech Research Institute (GTRI) and Honeywell International known as the Ball Grid Array (BGA) trap. This trap features 96 electrodes for fine control of the DC potential as well as a small footprint allowing for tight focusing of interaction lasers. We discuss the experimental system which utilizes the BGA trap, loading of Yb171 ions in this trap, and deterministic loading of chains of five or more ions. We hope to take advantage of the features of this new trap architecture in order to perform a small scale Boson Sampling experiment. This work is performed in collaboration with the GTRI Ion Trap Group and supported by ARO with funding from the IARPA MQCO program, and the AFOSR STTR on Atom Trap Chips.

  16. Ion beam analysis of defect trapping

    NASA Astrophysics Data System (ADS)

    Swanson, M. L.; Howe, L. M.

    1983-12-01

    Channeling measurements using medium energy ions (e.g. 1 MeV He +) have been used to determine the positions of solute atoms which are displaced from lattice sites by the trapping of vacancies and self-interstitial atoms. In this way, some simple defect trapping configurations have been identified in fcc metals. One of these is the mixed dumbbell (created when a self-interstitial is trapped by a small solute atom), consisting of a host atom and solute atom stradding a normal lattice site. Another is the tetravacancy-solute atom complex, consisting of four nearest neighbour vacancies surrounding a solute atom displaced into the tetrahedral interstitial site. In addition, from detailed analyses of displacements into different crystallographic channels as a function of irradiation fluence and annealing temperature, the evolution of a variety of defect complexes containing self-interstitials or vacancies has been studied in Al, Cu, Ni, Fe, and Mg crystals. Information from channeling analyses will be compared with data obtained from measurements of electrical resistivity, Mössbauer effect, perturbed angular correlation, extended X-ray absorption fine structure, muon precession, positron annihilation and internal friction. The advantages of the different methods will be discussed.

  17. Towards Quantum Simulations Using a Chip Ion Trap

    NASA Astrophysics Data System (ADS)

    Cao, Chenglin; Wright, Ken; Brennan, Daniel; Ji, Geoffrey; Monroe, Christopher

    2013-05-01

    We report our current experimental progress towards using chip ion traps for quantum simulation. Current progress is being made using a micro-fabricated symmetric trap from GTRI. This trap implements a novel two level design that combines the benefits of both surface traps and linear four-rod traps. The trap has 50 electrodes which allow for the fine control of the DC potential needed to create large anharmonic potentials, to join and split ion chains and to shuttle ions along the trapping axis similar to many surface traps. However this trap also has a much deeper trapping depth than conventional surface traps and improved optical access via an angled slot through the chip wide enough to accommodate higher power laser light which could cause surface charging or damage in a traditional chip trap. These advantages should allow trapping of long ion chains. We hope to use these features as the next step in increasing the size of current quantum simulations being done at Univ of Maryland, which are aimed at exploring quantum phenomena in spin systems in a regime inaccessible to classical simulation. This work is supported by grants from the U.S. Army Research Office with funding from the DARPA OLE program, IARPA, and the MURI program; and the NSF Physics Frontier Center at JQI. We acknowledge the GTRI team of J. Amini, K. Brown, A. Harter, F. Shaikh, R. Slusher, and C. Volin for the fabrication of the trap.

  18. Integrated Diffractive Optics for Surface Ion Traps

    NASA Astrophysics Data System (ADS)

    Streed, Erik; Ghadimi, Moji; Blums, Valdis; Norton, Benjamin; Connor, Paul; Amini, Jason; Volin, Curtis; Lobino, Mirko; Kielpinski, David

    2016-05-01

    Photonic interconnects are a bottleneck to achieving large-scale trapped ion quantum computing. We have modified a Georgia Tech Research Institute microwave chip trap by using e-beam lithography to write reflective diffractive collimating optics (80 μm x 127 μm, f=58.6 μm, λ=369.5nm) on the center electrode. The optics have an NA of 0.55 x 0.73, capturing 13.2% of the solid angle. To evaluate the optics 174Yb+ was loaded by isotope selective photo-ionization from a thermal oven and then shuttled to imaging sites. Near diffraction limited sub-wavelength ion images were obtained with an observed spot sized FWHM of 338 nm x 268 nm vs. a diffraction limit of 336 nm x 257 nm. The total photon collection efficiency was measured to be 5.2+/-1.2%. Coupling into a single mode fiber of up to 2.0+/-0.6% was observed, limited by mismatch in the coupling optics. Image mode quality indicates coupling up to 4% may be possible. Funding from Australian Research Council and IARPA.

  19. Trapped ion mode in toroidally rotating plasmas

    SciTech Connect

    Artun, M.; Tang, W.M.; Rewoldt, G.

    1995-04-01

    The influence of radially sheared toroidal flows on the Trapped Ion Mode (TIM) is investigated using a two-dimensional eigenmode code. These radially extended toroidal microinstabilities could significantly influence the interpretation of confinement scaling trends and associated fluctuation properties observed in recent tokamak experiments. In the present analysis, the electrostatic drift kinetic equation is obtained from the general nonlinear gyrokinetic equation in rotating plasmas. In the long perpendicular wavelength limit k{sub {tau}}{rho}{sub bi} {much_lt} 1, where {rho}{sub bi} is the average trapped-ion banana width, the resulting eigenmode equation becomes a coupled system of second order differential equations nmo for the poloidal harmonics. These equations are solved using finite element methods. Numerical results from the analysis of low and medium toroidal mode number instabilities are presented using representative TFTR L-mode input parameters. To illustrate the effects of mode coupling, a case is presented where the poloidal mode coupling is suppressed. The influence of toroidal rotation on a TFTR L-mode shot is also analyzed by including a beam species with considerable larger temperature. A discussion of the numerical results is presented.

  20. New ion trap for atomic frequency standard applications

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Dick, G. J.; Maleki, L.

    1989-01-01

    A novel linear ion trap that permits storage of a large number of ions with reduced susceptibility to the second-order Doppler effect caused by the radio frequency (RF) confining fields has been designed and built. This new trap should store about 20 times the number of ions a conventional RF trap stores with no corresponding increase in second-order Doppler shift from the confining field. In addition, the sensitivity of this shift to trapping parameters, i.e., RF voltage, RF frequency, and trap size, is greatly reduced.

  1. Computer simulations of ions in radio-frequency traps

    NASA Technical Reports Server (NTRS)

    Williams, A.; Prestage, J. D.; Maleki, L.; Djomehri, J.; Harabetian, E.

    1990-01-01

    The motion of ions in a trapped-ion frequency standard affects the stability of the standard. In order to study the motion and structures of large ion clouds in a radio-frequency (RF) trap, a computer simulation of the system that incorporates the effect of thermal excitation of the ions was developed. Results are presented from the simulation for cloud sizes up to 512 ions, emphasizing cloud structures in the low-temperature regime.

  2. Trap door and underside of cap stone of pyramid ion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Trap door and underside of cap stone of pyramid ion - Washington Monument, High ground West of Fifteenth Street, Northwest, between Independence & Constitution Avenues, Washington, District of Columbia, DC

  3. Ultra-stable Hg(+) trapped ion frequency standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. John; Maleki, Lute

    1990-01-01

    A fieldable trapped ion frequency standard based on Hg-199(+) ions confined in a hybrid rf/dc linear ion trap is developed. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the rf confining fields. In preliminary measurements a stability of 2 to 3 x 10(exp -15) was obtained for 10000 second averaging times. These measurements were carried out with a 120 mHz wide atomic resonance line for the 40.5 GHz clock transition with a second order Doppler shift from the rf trapping field of 6 x 10(exp -13).

  4. Resolved sideband spectra of calcium ions in a Penning trap

    NASA Astrophysics Data System (ADS)

    Goodwin, Joe; Stutter, Graham; Segal, Daniel; Thompson, Richard

    2013-03-01

    I report on recent work at Imperial College London, with laser cooled calcium-40 ion Coulomb crystals in Penning traps. Penning traps provide a number of advantages over the more common radiofrequency (RF) trap; namely the ability to trap 3-dimensional, micromotion-free ion Coulomb crystals, and the ability to produce deep traps while maintaining a large ion-electrode surface distance. While these factors should permit lower heating rates than in typical RF traps, very little research has been conducted into the behavior and control of small Coulomb crystals in Penning traps due to the experimental challenges involved. We have spent several years developing techniques to overcome these obstacles, and are now making rapid progress towards the sub-Doppler cooling and coherent control of small ion crystals. We have already observed high resolution optical spectra showing sidebands due to radial and axial motions, giving estimated temperatures close to the Doppler limit.

  5. Adjustable microchip ring trap for cold atoms and molecules

    SciTech Connect

    Baker, Paul M.; Stickney, James A.; Squires, Matthew B.; Scoville, James A.; Carlson, Evan J.; Buchwald, Walter R.; Miller, Steven M.

    2009-12-15

    We describe the design and function of a circular magnetic waveguide produced from wires on a microchip for atom interferometry using de Broglie waves. The guide is a two-dimensional magnetic minimum for trapping weak-field seeking states of atoms or molecules with a magnetic dipole moment. The design consists of seven circular wires sharing a common radius. We describe the design, the time-dependent currents of the wires and show that it is possible to form a circular waveguide with adjustable height and gradient while minimizing perturbation resulting from leads or wire crossings. This maximal area geometry is suited for rotation sensing with atom interferometry via the Sagnac effect using either cold atoms, molecules and Bose-condensed systems.

  6. Inhomogeneous spin diffusion in traps with cold atoms.

    PubMed

    Heiselberg, H

    2012-06-15

    The spin diffusion and damped oscillations are studied in the collision of two spin polarized clouds of cold atoms with resonant interactions. The strong density dependence of the diffusion coefficient leads to inhomogeneous spin diffusion that changes from central to surface spin flow as the temperature increases. The inhomogeneity and the smaller finite trap size significantly reduce the spin diffusion rate at low temperatures. The resulting spin diffusion rates and spin drag at longer time scales are compatible with measurements at low to high temperatures for resonant attractive interactions but are incompatible with a metastable ferromagnetic phase. This does not exclude that the colliding clouds can evolve into a repulsive initial state which subsequently decays during the bounce and the initial damped oscillations. PMID:23004287

  7. Inhomogeneous spin diffusion in traps with cold atoms.

    PubMed

    Heiselberg, H

    2012-06-15

    The spin diffusion and damped oscillations are studied in the collision of two spin polarized clouds of cold atoms with resonant interactions. The strong density dependence of the diffusion coefficient leads to inhomogeneous spin diffusion that changes from central to surface spin flow as the temperature increases. The inhomogeneity and the smaller finite trap size significantly reduce the spin diffusion rate at low temperatures. The resulting spin diffusion rates and spin drag at longer time scales are compatible with measurements at low to high temperatures for resonant attractive interactions but are incompatible with a metastable ferromagnetic phase. This does not exclude that the colliding clouds can evolve into a repulsive initial state which subsequently decays during the bounce and the initial damped oscillations.

  8. Test of Lorentz symmetry with trapped ions

    NASA Astrophysics Data System (ADS)

    Pruttivarasin, Thaned

    2016-05-01

    The outcome of an experiment should not depend on the orientation of the apparatus in space. This important cornerstone of physics is deeply engrained into the Standard Model of Physics by requiring that all fields must be Lorentz invariant. However, it is well-known that the Standard Model is incomplete. Some theories conjecture that at the Planck scale Lorentz symmetry might be broken and measurable at experimentally accessible energy scales. Therefore, a search for violation of Lorentz symmetry directly probes physics beyond the Standard model. We present a novel experiment utilizing trapped calcium ions as a direct probe of Lorentz-violation in the electron-photon sector. We monitor the energy between atomic states with different orientations of the electronic wave-functions as they rotate together with the motion of the Earth. This is analogous to the famous Michelson-Morley experiment. To remove magnetic field noise, we perform the experiment with the ions prepared in the decoherence-free states. Our result improves on the most stringent bounds on Lorentz symmetry for electrons by 100 times. The experimental scheme is readily applicable to many ion species, hence opening up paths toward much improved test of Lorentz symmetry in the future. (Ph. D. Advisor: Hartmut Haeffner, University of California, Berkeley).

  9. An Atomic Abacus: Trapped ion quantum computing experiments at NIST

    NASA Astrophysics Data System (ADS)

    Demarco, Brian

    2003-03-01

    Trapped atomic ions are an ideal system for exploring quantum information science because deterministic state preparation and efficient state detection are possible and coherent manipulation of atomic systems is relatively advanced. In our experiment, a few singly charged Be ions are confined by static and radio-frequency electric fields in a micro-machined linear Paul trap. The internal and motional states of the ions are coherently manipulated using applied laser light. Our current work focuses on demonstrating the necessary ingredients to produce a scalable quantum computing scheme and on simplifying and improving quantum logic gates. I will speak about a new set of experiments that was made possible by recent improvements in trap technology. A novel trap with multiple trapping regions was used to demonstrate the first steps towards a fully scalable quantum computing scheme. Single ions were ``shuttled" between trapping regions without disturbing the ion's motional and internal state, and two ions were separated from a single to two different trapping zones. Improvements in the trap manufacturing process has led to a reduction of nearly two orders of magnitude in the ion's motional heating rate, making possible two new improved logic gates. The first gate utilizes the wave-packet nature of the ions to tune the laser-atom interaction and achieve a controlled-NOT gate between a single ion's spin and motional states. The second, a two-ion phase gate, uses phase-space dynamics to produce a state-sensitive geometric phase. I will end with a quick look at experiments using a Mg ion to sympathetically cool a simultaneously trapped Be ion and a glimpse of the next generation of ions traps currently under construction.

  10. Ejection of Coulomb Crystals from a Linear Paul Ion Trap for Ion-Molecule Reaction Studies.

    PubMed

    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.

  11. Doppler Sideband Spectra for Ions in a Linear Trap

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Tjoelker, R. L.; Dick, G. J.; Maleki, L.

    1993-01-01

    We describe a spectroscopic measurement of the temperature and linear density of HG+ ions held in a linear ion trap (LIT). The inferred temperature and number result from analysis of sidebands on the 40.5 GHz resonance line.

  12. Trapped ion simulation of molecular spectrum

    NASA Astrophysics Data System (ADS)

    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.

  13. JPL Ultrastable Trapped Ion Atomic Frequency Standards.

    PubMed

    Burt, Eric A; Yi, Lin; Tucker, Blake; Hamell, Robert; Tjoelker, Robert L

    2016-07-01

    Recently, room temperature trapped ion atomic clock development at the Jet Propulsion Laboratory (JPL) has focused on three directions: 1) ultrastable atomic clocks, usually for terrestrial applications emphasizing ultimate stability performance and autonomous timekeeping; 2) new atomic clock technology for space flight applications that require strict adherence to size, weight, and power requirements; and 3) miniature clocks. In this paper, we concentrate on the first direction and present a design and the initial results from a new ultrastable clock referred to as L10 that achieves a short-term stability of 4.5 ×10(-14)/τ(1/2) and an initial measurement of no significant drift with an uncertainty of 2.4 ×10(-16) /day over a two-week period.

  14. JPL Ultrastable Trapped Ion Atomic Frequency Standards.

    PubMed

    Burt, Eric A; Yi, Lin; Tucker, Blake; Hamell, Robert; Tjoelker, Robert L

    2016-07-01

    Recently, room temperature trapped ion atomic clock development at the Jet Propulsion Laboratory (JPL) has focused on three directions: 1) ultrastable atomic clocks, usually for terrestrial applications emphasizing ultimate stability performance and autonomous timekeeping; 2) new atomic clock technology for space flight applications that require strict adherence to size, weight, and power requirements; and 3) miniature clocks. In this paper, we concentrate on the first direction and present a design and the initial results from a new ultrastable clock referred to as L10 that achieves a short-term stability of 4.5 ×10(-14)/τ(1/2) and an initial measurement of no significant drift with an uncertainty of 2.4 ×10(-16) /day over a two-week period. PMID:27249827

  15. Microfabricated quadrupole ion trap for mass spectrometer applications.

    PubMed

    Pau, S; Pai, C S; Low, Y L; Moxom, J; Reilly, P T A; Whitten, W B; Ramsey, J M

    2006-03-31

    An array of miniaturized cylindrical quadrupole ion traps, with a radius of 20 microm, is fabricated using silicon micromachining using phosphorus doped polysilicon and silicon dioxide for the purpose of creating a mass spectrometer on a chip. We have operated the array for mass-selective ion ejection and mass analysis using Xe ions at a pressure of 10(-4). The scaling rules for the ion trap in relation to operating pressure, voltage, and frequency are examined. PMID:16605890

  16. Four-Sector Cylindrical Radio-Frequency Ion Trap

    NASA Technical Reports Server (NTRS)

    Melbourne, Ruthann K.; Prestage, John D.; Maleki, Lutfollah

    1992-01-01

    Proposed linear radio-frequency ion trap consists of closed metal cylinder partitioned into four equal cylindrical-sector electrodes and two circular end electrodes. Features include relatively large ion-storage capacity and shielding against external fields. Used in frequency-standard laboratories to confine 199Hg+ ions electrodynamically in isolation from external environment. Similar to device described in "Linear Ion Trap for Atomic Clock" (NPO-17758).

  17. Progress Report on the Improved Linear Ion Trap Physics Package

    NASA Technical Reports Server (NTRS)

    Prestage, John D.

    1995-01-01

    This article describes the first operational results from the extended linear ion trap frequency standard now being developed at JPL. This new design separates the state selection/interrogation region from the more critical microwave resonance region where the multiplied local oscillator (LO) signal is compared to the stable atomic transition. Hg+ ions have been trapped, shuttled back and forth between the resonance and state selection traps. In addition, microwave transitions between the Hg+ clock levels have been driven in the resonance trap and detected in the state selection trap.

  18. An ion trap built with photonic crystal fibre technology

    SciTech Connect

    Lindenfelser, F. Keitch, B.; Kienzler, D.; Home, J. P.; Bykov, D.; Uebel, P.; Russell, P. St. J.

    2015-03-15

    We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787 ± 24 quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 μm and 10 μm.

  19. Cold ion escape from the Martian ionosphere

    NASA Astrophysics Data System (ADS)

    Fränz, M.; Dubinin, E.; Andrews, D.; Barabash, S.; Nilsson, H.; Fedorov, A.

    2015-12-01

    We here report on new measurements of the escape flux of oxygen ions from Mars by combining the observations of the ASPERA-3 and MARSIS experiments on board the European Mars Express spacecraft. We show that in previous estimates of the total heavy ion escape flow the contribution of the cold ionospheric outflow with energies below 10 eV has been underestimated. Both case studies and the derived flow pattern indicate that the cold plasma observed by MARSIS and the superthermal plasma observed by ASPERA-3 move with the same bulk speed in most regions of the Martian tail. We determine maps of the tailside heavy ion flux distribution derived from mean ion velocity distributions sampled over 7 years. If we assume that the superthermal bulk speed derived from these long time averages of the ion distribution function represent the total plasma bulk speed we derive the total tailside plasma flux. Assuming cylindrical symmetry we determine the mean total escape rate for the years 2007-2014 at 2.8 ± 0.4 ×1025 atoms / s which is in good agreement with model estimates. A possible mechanism to generate this flux can be the ionospheric pressure gradient between dayside and nightside.

  20. Highly Charged Ions in Rare Earth Permanent Magnet Penning Traps

    NASA Astrophysics Data System (ADS)

    Guise, Nicholas D.; Brewer, Samuel M.; Tan, Joseph N.

    A newly constructed apparatus at the United States National Institute of Standards and Technology (NIST) is designed for the isolation, manipulation, and study of highly charged ions. Highly charged ions are produced in the NIST electron-beam ion trap (EBIT), extracted through a beamline that selects a single mass/charge species, then captured in a compact Penning trap. The magnetic field of the trap is generated by cylindrical NdFeB permanent magnets integrated into its electrodes. In a room-temperature prototype trap with a single NdFeB magnet, species including Ne10+ and N7+ were confined with storage times of order 1 second, showing the potential of this setup for manipulation and spectroscopy of highly charged ions in a controlled environment. Ion capture has since been demonstrated with similar storage times in a more-elaborate Penning trap that integrates two coaxial NdFeB magnets for improved B-field homogeneity. Ongoing experiments utilize a second-generation apparatus that incorporates this two-magnet Penning trap along with a fast time-of-flight MCP detector capable of resolving the charge-state evolution of trapped ions. Holes in the two-magnet Penning trap ring electrode allow for optical and atomic beam access. Possible applications include spectroscopic studies of one-electron ions in Rydberg states, as well as highly charged ions of interest in atomic physics, metrology, astrophysics, and plasma diagnostics.

  1. Atomic physics measurements in an electron Beam Ion Trap

    SciTech Connect

    Marrs, R.E.; Beiersdorfer, P.; Bennett, C.; Chen, M.H.; Cowan, T.; Dietrich, D.; Henderson, J.R.; Knapp, D.A.; Osterheld, A.; Schneider, M.B.

    1989-03-01

    An electron Beam Ion Trap at Lawrence Livermore National Laboratory is being used to produce and trap very-highly-charged ions (q less than or equal to 70/+/) for x-ray spectroscopy measurements. Recent measurements of transition energies and electron excitation cross sections for x-ray line emission are summarized. 13 refs., 10 figs.

  2. How far can ion trap miniaturization go? Parameter scaling and space-charge limits for very small cylindrical ion traps.

    PubMed

    Tian, Yuan; Higgs, Jessica; Li, Ailin; Barney, Brandon; Austin, Daniel E

    2014-03-01

    A broad effort is underway to make radiofrequency (RF) ion trap mass spectrometers small enough for portable chemical analysis. A variety of trap geometries and fabrication approaches are under development from several research groups. A common issue is the reduced trapping capacity in smaller traps, with the associated reduction in sensitivity. This article explores the key variables that scale with trap size including RF voltage, frequency, electrical capacitance, power and pseudopotential well depth. High-field electric breakdown constrains the maximum RF voltages used in smaller ion traps. Simulations show the effects of space charge and the limits of trapping capacity as a function of trap dimensions for cylindrical ion traps down to the micrometer level. RF amplitudes that scale as the 1/3, 1/2 and 2/3 power of trap radius, r0, were studied. At a fixed level of performance, the number of analyzable ions scales as r0(n), with n ranging from 1.55 to 1.75 depending on the choice of voltage scaling. The implications for miniaturized ion trap mass spectrometry are discussed. PMID:24619549

  3. Blue-sky bifurcation of ion energies and the limits of neutral-gas sympathetic cooling of trapped ions

    PubMed Central

    Schowalter, Steven J.; Dunning, Alexander J.; Chen, Kuang; Puri, Prateek; Schneider, Christian; Hudson, Eric R.

    2016-01-01

    Sympathetic cooling of trapped ions through collisions with neutral buffer gases is critical to a variety of modern scientific fields, including fundamental chemistry, mass spectrometry, nuclear and particle physics, and atomic and molecular physics. Despite its widespread use over four decades, there remain open questions regarding its fundamental limitations. To probe these limits, here we examine the steady-state evolution of up to 10 barium ions immersed in a gas of three-million laser-cooled calcium atoms. We observe and explain the emergence of nonequilibrium behaviour as evidenced by bifurcations in the ion steady-state temperature, parameterized by ion number. We show that this behaviour leads to the limitations in creating and maintaining translationally cold samples of trapped ions using neutral-gas sympathetic cooling. These results may provide a route to studying non-equilibrium thermodynamics at the atomic level. PMID:27511602

  4. Blue-sky bifurcation of ion energies and the limits of neutral-gas sympathetic cooling of trapped ions

    NASA Astrophysics Data System (ADS)

    Schowalter, Steven J.; Dunning, Alexander J.; Chen, Kuang; Puri, Prateek; Schneider, Christian; Hudson, Eric R.

    2016-08-01

    Sympathetic cooling of trapped ions through collisions with neutral buffer gases is critical to a variety of modern scientific fields, including fundamental chemistry, mass spectrometry, nuclear and particle physics, and atomic and molecular physics. Despite its widespread use over four decades, there remain open questions regarding its fundamental limitations. To probe these limits, here we examine the steady-state evolution of up to 10 barium ions immersed in a gas of three-million laser-cooled calcium atoms. We observe and explain the emergence of nonequilibrium behaviour as evidenced by bifurcations in the ion steady-state temperature, parameterized by ion number. We show that this behaviour leads to the limitations in creating and maintaining translationally cold samples of trapped ions using neutral-gas sympathetic cooling. These results may provide a route to studying non-equilibrium thermodynamics at the atomic level.

  5. Blue-sky bifurcation of ion energies and the limits of neutral-gas sympathetic cooling of trapped ions.

    PubMed

    Schowalter, Steven J; Dunning, Alexander J; Chen, Kuang; Puri, Prateek; Schneider, Christian; Hudson, Eric R

    2016-01-01

    Sympathetic cooling of trapped ions through collisions with neutral buffer gases is critical to a variety of modern scientific fields, including fundamental chemistry, mass spectrometry, nuclear and particle physics, and atomic and molecular physics. Despite its widespread use over four decades, there remain open questions regarding its fundamental limitations. To probe these limits, here we examine the steady-state evolution of up to 10 barium ions immersed in a gas of three-million laser-cooled calcium atoms. We observe and explain the emergence of nonequilibrium behaviour as evidenced by bifurcations in the ion steady-state temperature, parameterized by ion number. We show that this behaviour leads to the limitations in creating and maintaining translationally cold samples of trapped ions using neutral-gas sympathetic cooling. These results may provide a route to studying non-equilibrium thermodynamics at the atomic level. PMID:27511602

  6. METHOD AND APPARATUS FOR TRAPPING IONS IN A MAGNETIC FIELD

    DOEpatents

    Luce, J.S.

    1962-04-17

    A method and apparatus are described for trapping ions within an evacuated container and within a magnetic field utilizing dissociation and/or ionization of molecular ions to form atomic ions and energetic neutral particles. The atomic ions are magnetically trapped as a result of a change of charge-to- mass ratio. The molecular ions are injected into the container and into the path of an energetic carbon arc discharge which dissociates and/or ionizes a portion of the molecular ions into atomic ions and energetic neutrals. The resulting atomic ions are trapped by the magnetic field to form a circulating beam of atomic ions, and the energetic neutrals pass out of the system and may be utilized in a particle accelerator. (AEC)

  7. Controlling trapping potentials and stray electric fields in a microfabricated ion trap through design and compensation

    NASA Astrophysics Data System (ADS)

    Doret, S. Charles; Amini, Jason M.; Wright, Kenneth; Volin, Curtis; Killian, Tyler; Ozakin, Arkadas; Denison, Douglas; Hayden, Harley; Pai, C.-S.; Slusher, Richart E.; Harter, Alexa W.

    2012-07-01

    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.

  8. Ion collision crosssection measurements in quadrupole ion traps using a time-frequency analysis method.

    PubMed

    He, Muyi; Guo, Dan; Chen, Yu; Xiong, Xingchuang; Fang, Xiang; Xu, Wei

    2014-12-01

    In this study, a method for measuring ion collision crosssections (CCSs) was proposed through time-frequency analysis of ion trajectories in quadrupole ion traps. A linear ion trap with added high-order electric fields was designed and simulated. With the presence of high-order electric fields and ion-neutral collisions, ion secular motion frequency within the quadrupole ion trap will be a function of ion motion amplitude, thus a function of time and ion CCS. A direct relationship was then established between ion CCS and ion motion frequency with respect to time, which could be obtained through time-frequency analysis of ion trajectories (or ion motion induced image currents). To confirm the proposed theory, realistic ion trajectory simulations were performed, where the CCSs of bradykinin, angiotensin I and II, and ubiquitin ions were calculated from simulated ion trajectories. As an example, differentiation of isomeric ubiquitin ions was also demonstrated in the simulations. PMID:25319271

  9. Electron source for a mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-12-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  10. Electron source for a mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  11. Compact toroidal ion-trap design and optimization

    SciTech Connect

    Madsen, M. J.; Gorman, C. H.

    2010-10-15

    We present the design of a type of compact toroidal, or 'halo', ion trap. Such traps may be useful for mass spectrometry, studying small Coulomb cluster rings, quantum-information applications, or other quantum simulations where a ring topology is of interest. We present results from a Monte Carlo optimization of the trap design parameters using finite-element analysis simulations that minimize higher-order anharmonic terms in the trapping pseudopotential, while maintaining complete control over ion placement at the pseudopotential node in three dimensions using static bias fields. These simulations are based on a practical electrode design using readily available parts, yet can be easily scaled to any size trap with similar electrode spacings. We also derive the conditions for a crystal structure transition for two ions in the compact halo trap, the first nontrivial transition for Coulomb crystals in this geometry.

  12. A Scalable Microfabricated Ion Trap for Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Maunz, Peter; Haltli, Raymond; Hollowell, Andrew; Lobser, Daniel; Mizrahi, Jonathan; Rembetski, John; Resnick, Paul; Sterk, Jonathan D.; Stick, Daniel L.; Blain, Matthew G.

    2016-05-01

    Trapped Ion Quantum Information Processing (QIP) relies on complex microfabricated trap structures to enable scaling of the number of quantum bits. Building on previous demonstrations of surface-electrode ion traps, we have designed and characterized the Sandia high-optical-access (HOA-2) microfabricated ion trap. This trap features high optical access, high trap frequencies, low heating rates, and negligible charging of dielectric trap components. We have observed trap lifetimes of more than 100h, measured trap heating rates for ytterbium of less than 40quanta/s, and demonstrated shuttling of ions from a slotted to an above surface region and through a Y-junction. Furthermore, we summarize demonstrations of high-fidelity single and two-qubit gates realized in this trap. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA).

  13. Ion sponge: a 3-dimentional array of quadrupole ion traps for trapping and mass-selectively processing ions in gas phase.

    PubMed

    Xu, Wei; Li, Linfan; Zhou, Xiaoyu; Ouyang, Zheng

    2014-05-01

    In this study, the concept of ion sponge has been explored for developing 3D arrays of large numbers of ion traps but with simple configurations. An ion sponge device with 484 trapping units in a volume of 10 × 10 × 3.2 cm has been constructed by simply stacking 9 meshes together. A single rf was used for trapping ions and mass-selective ion processing. The ion sponge provides a large trapping capacity and is highly transparent for transfer of ions, neutrals, and photons for gas phase ion processing. Multiple layers of quadrupole ion traps, with 121 trapping units in each layer, can operate as a single device for MS or MS/MS analysis, or as a series of mass-selective trapping devices with interlayer ion transfers facilitated by AC and DC voltages. Automatic sorting of ions to different trapping layers based on their mass-to-charge (m/z) ratios was achieved with traps of different sizes. Tandem-in-space MS/MS has also been demonstrated with precursor ions and fragment ions trapped in separate locations.

  14. Ion Sponge: A 3-Dimentional Array of Quadrupole Ion Traps for Trapping and Mass-Selectively Processing Ions in Gas Phase

    PubMed Central

    2015-01-01

    In this study, the concept of ion sponge has been explored for developing 3D arrays of large numbers of ion traps but with simple configurations. An ion sponge device with 484 trapping units in a volume of 10 × 10 × 3.2 cm has been constructed by simply stacking 9 meshes together. A single rf was used for trapping ions and mass-selective ion processing. The ion sponge provides a large trapping capacity and is highly transparent for transfer of ions, neutrals, and photons for gas phase ion processing. Multiple layers of quadrupole ion traps, with 121 trapping units in each layer, can operate as a single device for MS or MS/MS analysis, or as a series of mass-selective trapping devices with interlayer ion transfers facilitated by AC and DC voltages. Automatic sorting of ions to different trapping layers based on their mass-to-charge (m/z) ratios was achieved with traps of different sizes. Tandem-in-space MS/MS has also been demonstrated with precursor ions and fragment ions trapped in separate locations. PMID:24758328

  15. Ion trap array mass analyzer: structure and performance.

    PubMed

    Li, Xiaoxu; Jiang, Gongyu; Luo, Chan; Xu, Fuxing; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2009-06-15

    An ion trap array (ITA) mass analyzer--a novel ion trap mass analyzer with multiple ion trapping and analyzing channels--was designed and constructed. Its property and performance were investigated and reported in this paper. The ITA was built with several planar electrodes including two parallel printed circuit board (PCB) plates. Each PCB plate was fabricated to several identical rectangular electric strips based on normal PCB fabrication technology and was placed symmetrically to those on the opposite plate. There is no electrode between any two adjacent strips. Every strip was supplied with an rf voltage while the polarity of the voltage applied to the adjacent two strips was opposite. So the electric potential at the central plane between two adjacent strips is zero. Multiple identical electric field regions that contain the dominant quadrupole plus some other high-order fields were produced between the two PCB plates. The multiple identical electric field regions will have the property of ion trapping, ion storage, and mass analysis functions. So an ITA could work as multiple ion trap mass analyzers. It could perform multiple sample ion storage, mass-selected ion isolation, ion ejection, and mass analysis simultaneously. The ITA was operated at both "digital ion trap mode" and "conventional rf mode" experimentally. A preliminary mass spectrum has been carried out in one of the ion trap channels, and it shows a mass resolution of over 1000. Additional functions such as mass-selected ion isolation and mass-selected ion ejection have also been tested. Furthermore, the ITA has a small size and very low cost. An ITA with four channels is less than 30 cm(3) in total volume, and it shows a great promise for the miniaturization of the whole mass spectrometer instrument and high-throughput mass analysis. PMID:19441854

  16. A system for trapping barium ions in a microfabricated surface trap

    SciTech Connect

    Graham, R. D. Sakrejda, T.; Wright, J.; Zhou, Z.; Blinov, B. B.; Chen, S.-P.

    2014-05-15

    We have developed a vacuum chamber and control system for rapid testing of microfabricated surface ion traps. Our system is modular in design and is based on an in-vacuum printed circuit board with integrated filters. We have used this system to successfully trap and cool barium ions and have achieved ion ‘dark' lifetimes of 31.6 s ± 3.4 s with controlled shuttling of ions. We provide a detailed description of the ion trap system including the in-vacuum materials used, control electronics and neutral atom source. We discuss the challenges presented in achieving a system which can work reliably over two years of operations in which the trap under test was changed at least 10 times.

  17. Rydberg excitation of trapped strontium ions (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hennrich, Markus; Higgins, Gerard; Pokorny, Fabian; Kress, Florian; Maier, Christine; Haag, Johannes; Colombe, Yves

    2016-04-01

    Trapped Rydberg ions are a novel approach for quantum information processing [1,2]. This idea joins the advanced quantum control of trapped ions with the strong dipolar interaction between Rydberg atoms. For trapped ions this method promises to speed up entangling interactions [3] and to enable such operations in larger ion crystals [4]. We report on the first experimental realization of trapped strontium Rydberg ions. A single ion was confined in a linear Paul trap and excited to Rydberg states (25S to 37S) using a two-photon excitation with 243nm and 308nm laser light. The transitions we observed are narrow and the excitation can be performed repeatedly which indicates that the Rydberg ions are stable in the ion trap. Similar results have been recently reported on a single photon Rydberg excitation of trapped calcium ions [5]. The tunability of the 304-309nm laser should enable us to excite our strontium ions to even higher Rydberg levels. Such highly excited levels are required to achieve a strong interaction between neighboring Rydberg ions in the trap as will be required for quantum gates using the Rydberg interaction. References [1] M. Müller, L. Liang, I. Lesanovsky, P. Zoller, New J. Phys. 10, 093009 (2008). [2] F. Schmidt-Kaler, et al., New J. Phys. 13, 075014 (2011). [3] W. Li, I. Lesanovsky, Appl. Phys. B 114, 37-44 (2014). [4] W. Li, A.W. Glaetzle, R. Nath, I. Lesanovsky, Phys. Rev. A 87, 052304 (2013). [5] T. Feldker, et al., arXiv:1506.05958

  18. Spectroscopic studies of cold, gas-phase biomolecular ions

    NASA Astrophysics Data System (ADS)

    Rizzo, Thomas R.; Stearns, Jaime A.; Boyarkin, Oleg V.

    While the marriage of mass spectrometry and laser spectroscopy is not new, developments over the last few years in this relationship have opened up new horizons for the spectroscopic study of biological molecules. The combination of electrospray ionisation for producing large biological molecules in the gas phase together with cooled ion traps and multiple-resonance laser schemes are allowing spectroscopic investigation of individual conformations of peptides with more than a dozen amino acids. Highly resolved infrared spectra of single conformations of such species provide important benchmarks for testing the accuracy of theoretical calculations. This review presents a number of techniques employed in our laboratory and in others for measuring the spectroscopy of cold, gas-phase protonated peptides. We show examples that demonstrate the power of these techniques and evaluate their extension to still larger biological molecules.

  19. Magnetic trapping of long-lived cold Rydberg atoms.

    PubMed

    Choi, J-H; Guest, J R; Povilus, A P; Hansis, E; Raithel, G

    2005-12-01

    We report on the trapping of long-lived strongly magnetized Rydberg atoms. 85Rb atoms are laser cooled and collected in a superconducting magnetic trap with a strong bias field (2.9 T) and laser excited to Rydberg states. Collisions scatter a small fraction of the Rydberg atoms into long-lived high-angular momentum "guiding-center" Rydberg states, which are magnetically trapped. The Rydberg atomic cloud is examined using a time-delayed, position-sensitive probe. We observe magnetic trapping of these Rydberg atoms for times up to 200 ms. Oscillations of the Rydberg-atom cloud in the trap reveal an average magnetic moment of the trapped Rydberg atoms of approximately -8microB. These results provide guidance for other Rydberg-atom trapping schemes and illuminate a possible route for trapping antihydrogen.

  20. Magnetic Trapping of Long-Lived Cold Rydberg Atoms

    SciTech Connect

    Choi, J.-H.; Guest, J.R.; Povilus, A.P.; Hansis, E.; Raithel, G.

    2005-12-09

    We report on the trapping of long-lived strongly magnetized Rydberg atoms. {sup 85}Rb atoms are laser cooled and collected in a superconducting magnetic trap with a strong bias field (2.9 T) and laser excited to Rydberg states. Collisions scatter a small fraction of the Rydberg atoms into long-lived high-angular momentum 'guiding-center' Rydberg states, which are magnetically trapped. The Rydberg atomic cloud is examined using a time-delayed, position-sensitive probe. We observe magnetic trapping of these Rydberg atoms for times up to 200 ms. Oscillations of the Rydberg-atom cloud in the trap reveal an average magnetic moment of the trapped Rydberg atoms of {approx_equal}-8{mu}{sub B}. These results provide guidance for other Rydberg-atom trapping schemes and illuminate a possible route for trapping antihydrogen.

  1. Recent developments in ion detection techniques for Penning trap mass spectrometry at TRIGA-TRAP

    NASA Astrophysics Data System (ADS)

    Ketelaer, J.; Blaum, K.; Block, M.; Eberhardt, K.; Eibach, M.; Ferrer, R.; George, S.; Herfurth, F.; Ketter, J.; Nagy, Sz.; Repp, J.; Schweikhard, L.; Smorra, C.; Sturm, S.; Ulmer, S.

    2009-12-01

    The highest precision in the determination of nuclear and atomic masses can be achieved by Penning trap mass spectrometry. The mass value is obtained through a measurement of the cyclotron frequency of the stored charged particle. Two different approaches are used at the Penning trap mass spectrometer TRIGA-TRAP for the mass determination: the destructive Time-Of-Flight Ion Cyclotron Resonance (TOF-ICR) technique and the non-destructive Fourier Transform Ion Cyclotron Resonance (FT-ICR) method. New developments for both techniques are described, which will improve the detection efficiency and the suppression of contaminations in the case of TOF-ICR. The FT-ICR detection systems will allow for the investigation of an incoming ion bunch from a radioactive-beam facility on the one hand, and for the detection of a single singly charged ion in the Penning trap on the other hand.

  2. In-trap spectroscopy of charge-bred radioactive ions.

    PubMed

    Lennarz, A; Grossheim, A; Leach, K G; Alanssari, M; Brunner, T; Chaudhuri, A; Chowdhury, U; Crespo López-Urrutia, J R; Gallant, A T; Holl, M; Kwiatkowski, A A; Lassen, J; Macdonald, T D; Schultz, B E; Seeraji, S; Simon, M C; Andreoiu, C; Dilling, J; Frekers, D

    2014-08-22

    In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, ^{124}In and ^{124}Cs) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (ββ) decay.

  3. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time.

  4. Experimental demonstration of a surface-electrode multipole ion trap

    NASA Astrophysics Data System (ADS)

    Maurice, Mark; Allen, Curtis; Green, Dylan; Farr, Andrew; Burke, Timothy; Hilleke, Russell; Clark, Robert

    2015-08-01

    We report on the design and experimental characterization of a surface-electrode multipole ion trap. Individual microscopic sugar particles are confined in the trap. The trajectories of driven particle motion are compared with a theoretical model, both to verify qualitative predictions of the model and to measure the charge-to-mass ratio of the confined particle. The generation of harmonics of the driving frequency is observed as a key signature of the nonlinear nature of the trap. We remark on possible applications of our traps, including to mass spectrometry.

  5. Temperature and heating rate of ion crystals in Penning traps

    SciTech Connect

    Jensen, Marie J.; Hasegawa, Taro; Bollinger, John J.

    2004-09-01

    We have determined the temperature and heating rate of laser-cooled ions in a Penning trap using Doppler laser spectroscopy. Between 10{sup 4} and 10{sup 6} {sup 9}Be{sup +} ions are trapped in a Penning trap and Doppler laser cooled to temperatures of a few millikelvin, where they form ion crystals. This system is an example of a strongly coupled one-component plasma. The ion temperature was measured as a function of time after turning off the laser-cooling. In the solid phase, we measured a heating rate of {approx}65 mK/s. Information about possible heating mechanisms was obtained directly from temperature measurements, and also from measurements of the rate of radial expansion of the ion plasma. We determined that the observed heating is due to collisions with the {approx}4x10{sup -9} Pa residual gas of our vacuum system.

  6. Optical cavity integrated surface ion trap for enhanced light collection

    NASA Astrophysics Data System (ADS)

    Benito, Francisco M.

    Ion trap systems allow the faithful storage and manipulation of qubits encoded in the energy levels of the ions, and can be interfaced with photonic qubits that can be transmitted to connect remote quantum systems. Single photons transmitted from two remote sites, each entangled with one quantum memory, can be used to entangle distant quantum memories by interfering on a beam splitter. Efficient remote entanglement generation relies upon efficient light collection from single ions into a single mode fiber. This can be realized by integrating an ion trap with an optical cavity and employing the Purcell effect for enhancing the light collection. Remote entanglement can be used as a resource for a quantum repeater for provably secure long-distance communication or as a method for communicating within a distributed quantum information processor. We present the integration of a 1 mm optical cavity with a micro-fabricated surface ion trap. The plano-concave cavity is oriented normal to the chip surface where the planar mirror is attached underneath the trap chip. The cavity is locked using a 780 nm laser which is stabilized to Rubidium and shifted to match the 369 nm Doppler transition in Ytterbium. The linear ion trap allows ions to be shuttled in and out of the cavity mode. The Purcell enhancement of spontaneous emission into the cavity mode would then allow efficient collection of the emitted photons, enabling faster remote entanglement generation.

  7. Towards Non-Equilibrium Dynamics with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Silbert, Ariel; Jubin, Sierra; Doret, Charlie

    2016-05-01

    Atomic systems are superbly suited to the study of non-equilibrium dynamics. These systems' exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of far-from-equilibrium phenomena. One example of particular relevance to experiments in trapped ion quantum information processing, metrology, and precision spectroscopy is the approach to thermal equilibrium of sympathetically cooled linear ion chains. Suitable manipulation of experimental parameters permits exploration of the quantum-to-classical crossover between ballistic transport and diffusive, Fourier's Law conduction, a topic of interest not only to the trapped ion community but also for the development of microelectronic devices and other nanoscale structures. We present progress towards trapping chains of multiple co-trapped calcium isotopes geared towards measuring thermal equilibration and discuss plans for future experiments in non-equilibrium statistical mechanics. This work is supported by Cottrell College Science Award from the Research Corporation for Science Advancement and by Williams College.

  8. Method and apparatus for regenerating cold traps within liquid-metal systems

    DOEpatents

    McKee, Jr., John M.

    1976-01-01

    Oxide and hydride impurities of a liquid metal such as sodium are removed from a cold trap by heating to a temperature at which the metal hydroxide is stable in a molten state. The partial pressure of hydrogen within the system is measured to determine if excess hydride or oxide is present. Excess hydride is removed by venting hydrogen gas while excess oxide can be converted to molten hydroxide through the addition of hydrogen. The resulting, molten hydroxide is drained from the trap which is then returned to service at cold trap temperatures within the liquid-metal system.

  9. Heavy ion plasma confinement in an RF quadrupole trap

    NASA Technical Reports Server (NTRS)

    Schermann, J.; Major, F. G.

    1971-01-01

    The confinement of an electron free plasma in a pure quadrupole RF electric trap was considered. The ultimate goal was to produce a large density of mercury ions, in order to realize a trapped ion frequency standard using the hyperfine resonance of 199 Hg(+) at 40.7 GHz. An attempt was made to obtain an iodine plasma consisting of equal numbers of positive and negative ions of atomic iodine, the positive iodine ions, being susceptible to charge-exchange with mercury atoms, will produce the desired mercury ions. The experiment showed that the photoproduction of ions pairs in iodine using the necessary UV radiation occurs with a small cross-section, making it difficult to demonstrate the feasibility of space charge neutralization in a quadrupole trap. For this reason it was considered expedient to choose thallium iodide, which has a more favorable absorption spectrum (in the region of 2000 to 2100 A). The results indicate that, although the ionic recombination is a serious limiting factor, a considerable improvement can be obtained in practice for the density of trapped ions, with a considerable advantage in lifetimes for spectroscopic purposes. The ion pair formation by photoionization is briefly reviewed.

  10. Toward Quantum Simulation with 9Be+ Ions in a Penning Trap

    NASA Astrophysics Data System (ADS)

    Sawyer, Brian; Britton, Joe; Uys, Hermann; Biercuk, Michael; Bollinger, John

    2011-05-01

    Experimental progress in the fields of atomic and molecular physics has allowed exquisite control over ensembles of cold and ultracold ions, neutral atoms, and polar molecules. A number of theoretical proposals have been put forward concerning direct simulation of quantum Hamiltonians in these systems. We report progress toward simulation of the transverse Ising model in a two-dimensional Coulomb crystal of ~100 9Be+ ions confined within a Penning trap. Coupling between ions is controlled via optical dipole forces, thereby facilitating a wide range of interparticle interactions including infinite-range and nearest-neighbor coupling. Furthermore, the triangular lattice structure readily obtained within the planar Coulomb crystal allows for simulation of spin frustration in an antiferromagnetic system. Given our large ensembles of trapped 9Be+, it may be possible to perform quantum simulations that are currently intractable with classical computers. We acknowledge funding support from the DARPA OLE program.

  11. Ion trap simulations of quantum fields in an expanding universe.

    PubMed

    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.

  12. A Linear RFQ Ion Trap for the Enriched Xenon Observatory

    SciTech Connect

    Flatt, B.; Green, M.; Wodin, J.; DeVoe, R.; Fierlinger, P.; Gratta, G.; LePort, F.; Montero Diez, M.; Neilson, R.; O'Sullivan, K.; Pocar, A.; Baussan, E.; Breidenbach, M.; Conley, R.; Fairbank Jr., W.; Farine, J.; Hall, K.; Hallman, D.; Hargrove, C.; Hauger, M.; Hodgson, J.; /Stanford U., Phys. Dept. /Neuchatel U. /SLAC /Colorado State U. /Laurentian U. /Carleton U. /Alabama U.

    2008-01-14

    The design, construction, and performance of a linear radio-frequency ion trap (RFQ) intended for use in the Enriched Xenon Observatory (EXO) are described. EXO aims to detect the neutrinoless double-beta decay of {sup 136}Xe to {sup 136}Ba. To suppress possible backgrounds EXO will complement the measurement of decay energy and, to some extent, topology of candidate events in a Xe filled detector with the identification of the daughter nucleus ({sup 136}Ba). The ion trap described here is capable of accepting, cooling, and confining individual Ba ions extracted from the site of the candidate double-beta decay event. A single trapped ion can then be identified, with a large signal-to-noise ratio, via laser spectroscopy.

  13. Model-based exploration of the drivers of mountain cold-trapping in soil.

    PubMed

    Westgate, John N; Wania, Frank

    2013-12-01

    A pollutant is said to undergo mountain cold-trapping if it is found at higher concentrations in a surface medium (soil, snow, foliage) high on a mountain, where it is colder, than in the same medium lower on the mountain. The processes that lead to mountain cold-trapping in soil were explored for a set of hypothetical Perfectly Persistent Pollutants (PPPs) by varying several environmental parameters in a fugacity based fate and transport box model. These parameters were: the spatial scale of the mountain; the rate and location of rain; the amount of particles in the atmosphere; the presence and magnitude of the upslope temperature gradient. The relative potential of each hypothetical PPP to exhibit mountain cold-trapping was expressed in terms of its Mountaintop Contamination Potential (MCP). The PPPs with the highest MCPs were those that neither were deposited from the atmosphere to the surface in the lower zones in the model nor left the model domain without being deposited at all. The simulations revealed that under most conditions wet-gaseous deposition is the biggest driver of mountain cold-trapping in soils, and its effects are greatly enhanced by large negative temperature gradients and increased precipitation upslope. Dry-gaseous and wet-and-dry-particle deposition processes cause similar PPPs to exhibit mountain cold-trapping, and the contributions to MCP by the dry processes are of the same magnitude as wet-particle deposition. Dry gaseous deposition alone is insufficient to cause mountain cold-trapping in soils under any conditions modelled here. Those measuring organic contaminants in mountains should expect to find that mountains with different climates cold-trap different pollutants, and that some mountains may not exhibit upslope enrichment of any species.

  14. Reducing Motional Decoherence in Ion Traps with Surface Science Methods

    NASA Astrophysics Data System (ADS)

    Haeffner, Hartmut

    2014-03-01

    Many trapped ions experiments ask for low motional heating rates while trapping the ions close to trapping electrodes. However, in practice small ion-electrode distances lead to unexpected high heating rates. While the mechanisms for the heating is still unclear, it is now evident that surface contamination of the metallic electrodes is at least partially responsible for the elevated heating rates. I will discuss heating rate measurements in a microfabricated surface trap complemented with basic surface science studies. We monitor the elemental surface composition of the Cu-Al alloy trap with an Auger spectrometer. After bake-out, we find a strong Carbon and Oxygen contamination and heating rates of 200 quanta/s at 1 MHz trap frequency. After removing most of the Carbon and Oxygen with Ar-Ion sputtering, the heating rates drop to 4 quanta/s. Interestingly, we still measure the decreased heating rate even after the surface oxidized from the background gas throughout a 40-day waiting time in UHV.

  15. Parallel Transport Quantum Logic Gates with Trapped Ions.

    PubMed

    de Clercq, Ludwig E; Lo, Hsiang-Yu; Marinelli, Matteo; Nadlinger, David; Oswald, Robin; Negnevitsky, Vlad; Kienzler, Daniel; Keitch, Ben; Home, Jonathan P

    2016-02-26

    We demonstrate single-qubit operations by transporting a beryllium ion with a controlled velocity through a stationary laser beam. We use these to perform coherent sequences of quantum operations, and to perform parallel quantum logic gates on two ions in different processing zones of a multiplexed ion trap chip using a single recycled laser beam. For the latter, we demonstrate individually addressed single-qubit gates by local control of the speed of each ion. The fidelities we observe are consistent with operations performed using standard methods involving static ions and pulsed laser fields. This work therefore provides a path to scalable ion trap quantum computing with reduced requirements on the optical control complexity. PMID:26967401

  16. Global gyrokinetic simulations of trapped-electron mode and trapped-ion mode microturbulence

    NASA Astrophysics Data System (ADS)

    Drouot, T.; Gravier, E.; Reveille, T.; Sarrat, M.; Collard, M.; Bertrand, P.; Cartier-Michaud, T.; Ghendrih, P.; Sarazin, Y.; Garbet, X.

    2015-08-01

    This paper presents a reduced kinetic model, which describes simultaneously trapped-ion (TIM) and trapped-electron (TEM) driven modes. Interestingly, the model enables the study of a full f problem for ion and electron trapped particles at very low numerical cost. The linear growth rate obtained with the full f nonlinear code Trapped Element REduction in Semi Lagrangian Approach is successfully compared with analytical predictions. Moreover, nonlinear results show some basic properties of collisionless TEM and TIM turbulence in tokamaks. A competition between streamer-like structures and zonal flows is observed for TEM and TIM turbulence. Zonal flows are shown to play an important role in suppressing the nonlinear transport and strongly depend on the temperature ratio Te/Ti .

  17. Collisional activation with random noise in ion trap mass spectrometry

    SciTech Connect

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1992-07-01

    Random noise applied to the end caps of a quadrupole ion trap is shown to be an effective means for the collisional activation of trapped ions independent of mass/charge ratio and number of ions. This technique is compared and contrasted with conventional single-frequency collisional activation for the molecular ion of N,N-dimethylaniline, protonated cocaine, the molecular anion of 2,4,6-trinitrotoluene, and doubly protonated neuromedin U-8. Collisional activation with noise tends to produce more extensive fragmentation than the conventional approach due to the fact that product ions are also kinetically excited in the noise experiment. The efficiency of the noise experiment in producing detectable product ions relative to the conventional approach ranges from being equivalent to being a factor of 3 less efficient. Furthermore, discrimination against low mass/charge product ions is apparent in the data from multiply charged biomolecules. Nevertheless, collisional activation with random noise provides a very simple means for overcoming problems associated with the dependence of single-frequency collisional activation on mass/charge ratio and the number of ions in the ion trap. 45 refs., 7 figs.

  18. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology.

    PubMed

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-08-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry. Graphical Abstract ᅟ. PMID:27150507

  19. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology

    NASA Astrophysics Data System (ADS)

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-08-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry.

  20. Electrostatic particle trap for ion beam sputter deposition

    DOEpatents

    Vernon, Stephen P.; Burkhart, Scott C.

    2002-01-01

    A method and apparatus for the interception and trapping of or reflection of charged particulate matter generated in ion beam sputter deposition. The apparatus involves an electrostatic particle trap which generates electrostatic fields in the vicinity of the substrate on which target material is being deposited. The electrostatic particle trap consists of an array of electrode surfaces, each maintained at an electrostatic potential, and with their surfaces parallel or perpendicular to the surface of the substrate. The method involves interception and trapping of or reflection of charged particles achieved by generating electrostatic fields in the vicinity of the substrate, and configuring the fields to force the charged particulate material away from the substrate. The electrostatic charged particle trap enables prevention of charged particles from being deposited on the substrate thereby enabling the deposition of extremely low defect density films, such as required for reflective masks of an extreme ultraviolet lithography (EUVL) system.

  1. Mountain cold-trapping increases transfer of persistent organic pollutants from atmosphere to cows' milk.

    PubMed

    Shunthirasingham, Chubashini; Wania, Frank; MacLeod, Matthew; Lei, Ying Duan; Quinn, Cristina L; Zhang, Xianming; Scheringer, Martin; Wegmann, Fabio; Hungerbühler, Konrad; Ivemeyer, Silvia; Heil, Fritz; Klocke, Peter; Pacepavicius, Grazina; Alaee, Mehran

    2013-08-20

    Concentrations of long-lived organic contaminants in snow, soil, lake water, and vegetation have been observed to increase with altitude along mountain slopes. Such enrichment, called "mountain cold-trapping", is attributed to a transition from the atmospheric gas phase to particles, rain droplets, snowflakes, and Earth's surface at the lower temperatures prevailing at higher elevations. Milk sampled repeatedly from cows that had grazed at three different altitudes in Switzerland during one summer was analyzed for a range of persistent organic pollutants. Mountain cold-trapping significantly increased air-to-milk transfer factors of most analytes. As a result, the milk of cows grazing at higher altitudes was more contaminated with substances that have regionally uniform air concentrations (hexachlorobenzene, α-hexachlorocyclohexane, endosulfan sulfate). For substances that have sources, and therefore higher air concentrations, at lower altitudes (polychlorinated biphenyls, γ-hexachlorocyclohexane), alpine milk has lower concentrations, but not as low as would be expected without mountain cold-trapping. Differences in the elevational gradients in soil concentrations and air-to-milk transfer factors highlight that cold-trapping of POPs in pastures is mostly due to increased gas-phase deposition as a result of lower temperatures causing higher uptake capacity of plant foliage, whereas cold-trapping in soils more strongly depends on wet and dry particle deposition. Climatic influences on air-to-milk transfer of POPs needs to be accounted for when using contamination of milk lipids to infer contamination of the atmosphere. PMID:23885857

  2. Magnetic levitation for effective loading of cold cesium atoms in a crossed dipole trap

    NASA Astrophysics Data System (ADS)

    Li, Yuqing; Feng, Guosheng; Xu, Rundong; Wang, Xiaofeng; Wu, Jizhou; Chen, Gang; Dai, Xingcan; Ma, Jie; Xiao, Liantuan; Jia, Suotang

    2015-05-01

    We report a detailed study of effective magnetically levitated loading of cold atoms in a crossed dipole trap: an appropriate magnetic field gradient precisely compensates for the destructive gravitational force of the atoms and an additional bias field simultaneously eliminates the antitrapping potential induced by the magnetic field gradient. The magnetic levitation is required for a large-volume crossed dipole trap to form a shallow but very effective loading potential, making it a promising method for loading and trapping more cold atoms. For cold cesium atoms in the F =3 , m F =3 state prepared by three-dimensional degenerated Raman sideband cooling, a large number of atoms ˜3.2 ×106 have been loaded into a large-volume crossed dipole trap with the help of the magnetic levitation technique. The dependence of the number of atoms loaded and trapped in the dipole trap on the magnetic field gradient and bias field, respectively, is in good agreement with the theoretical analysis. The optimum magnetic field gradient of 31.13 G/cm matches the theoretical value of 31.3 G/cm well. This method can be used to obtain more cold atoms or a large number of Bose-Einstein condensation atoms for many atomic species in high-field seeking states.

  3. Defect trapping of ion-implanted deuterium in nickel

    SciTech Connect

    Besenbacher, F.; Bottiger, J.; Myers, S.M.

    1982-05-01

    Trapping of ion-implanted deuterium by lattice defects in nickel has been studied by ion-beam-analysis techniques in the temperature range between 30 and 380 K. The deuterium-depth profiles were determined by measuring either the ..cap alpha.. particles or the protons from the /sup 3/He-excited nuclear reaction D(/sup 3/He,..cap alpha..)p, and the deuterium lattice location was obtained by means of ion channeling. Linear-ramp annealing (1 K/min) following a 10-keV D/sup +/ implantation in nickel produced two annealing stages at 275 and 320 K, respectively. The release-vs-temperature data were analyzed by solving the diffusion equation with appropriate trapping terms, yielding 0.24 and 0.43 eV for the trap-binding enthalpies associated with the two stages, referred to as an untrapped solution site. The 0.24-eV trap corresponds to deuterium close to the octahedral interstitial site where it is believed to be trapped at a vacancy, whereas it is suggested that the defect correlated with the 0.43-eV trap is a multiple-vacancy defect. The previously air-exposed and electropolished nickel surface was essentially permeable; the surface-recombination coefficient was determined to be K> or approx. =10/sup -19/ cm/sup 4//s at 350 K.

  4. Laser desorption in an ion trap mass spectrometer

    SciTech Connect

    Eiden, G.C.; Cisper, M.E.; Alexander, M.L.; Hemberger, P.H.; Nogar, N.S.

    1993-02-01

    Laser desorption in a ion-trap mass spectrometer shows significant promise for both qualitative and trace analysis. Several aspects of this methodology are discussed in this work. We previously demonstrated the generation of both negative and positive ions by laser desorption directly within a quadrupole ion trap. In the present work, we explore various combinations of d.c., r.f., and time-varying fields in order to optimize laser generated signals. In addition, we report on the application of this method to analyze samples containing compounds such as amines, metal complexes, carbon clusters, and polynuclear aromatic hydrocarbons. In some cases the ability to rapidly switch between positive and negative ion modes provides sufficient specificity to distinguish different compounds of a mixture with a single stage of mass spectrometry. In other experiments, we combined intensity variation studies with tandem mass spectrometry experiments and positive and negative ion detection to further enhance specificity.

  5. Single Ion Trapping for the Enriched Xenon Observatory

    SciTech Connect

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

    2006-03-28

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

  6. Towards Laser Cooling Trapped Ions with Telecom Light

    NASA Astrophysics Data System (ADS)

    Dungan, Kristina; Becker, Patrick; Donoghue, Liz; Liu, Jackie; Olmschenk, Steven

    2015-05-01

    Quantum information has many potential applications in communication, atomic clocks, and the precision measurement of fundamental constants. Trapped ions are excellent candidates for applications in quantum information because of their isolation from external perturbations, and the precise control afforded by laser cooling and manipulation of the quantum state. For many applications in quantum communication, it would be advantageous to interface ions with telecom light. We present progress towards laser cooling and trapping of doubly-ionized lanthanum, which should require only infrared, telecom-compatible light. Additionally, we present progress on optimization of a second-harmonic generation cavity for laser cooling and trapping barium ions, for future sympathetic cooling experiments. This research is supported by the Army Research Office, Research Corporation for Science Advancement, and Denison University.

  7. Investigation of nonextensivity trapped electrons effect on the solitary ion-acoustic wave using fractional Schamel equation

    NASA Astrophysics Data System (ADS)

    Nazari-Golshan, A.

    2016-08-01

    Ion-acoustic (IA) solitary wave propagation is investigated by solving the fractional Schamel equation (FSE) in a homogenous system of unmagnetized plasma. This plasma consists of the nonextensive trapped electrons and cold fluid ions. The effects of the nonextensive q-parameter, electron trapping, and fractional parameter have been studied. The FSE is derived by using the semi-inverse and Agrawal's methods. The analytical results show that an increase in the amount of electron trapping and nonextensive q-parameter increases the soliton ion-acoustic amplitude in agreement with the previously obtained results. However, it is vice-versa for the fractional parameter. This feature leads to the fact that the fractional parameter may be used to increase the IA soliton amplitude instead of increasing electron trapping and nonextensive parameters.

  8. Ion trap collision-induced dissociation of locked nucleic acids.

    PubMed

    Huang, Teng-yi; Kharlamova, Anastasia; McLuckey, Scott A

    2010-01-01

    Gas-phase dissociation of model locked nucleic acid (LNA) oligonucleotides and functional LNA-DNA chimeras have been investigated as a function of precursor ion charge state using ion trap collision-induced dissociation (CID). For the model LNA 5 and 8 mer, containing all four LNA monomers in the sequence, cleavage of all backbone bonds, generating a/w-, b/x-, c/y-, and d/z-ions, was observed with no significant preference at lower charge states. Base loss ions, except loss of thymine, from the cleavage of N-glycosidic bonds were also present. In general, complete sequence coverage was achieved in all charge states. For the two LNA-DNA chimeras, however, dramatic differences in the relative contributions of the competing dissociation channels were observed among different precursor ion charge states. At lower charge states, sequence information limited to the a-Base/w-fragment ions from cleavage of the 3'C-O bond of DNA nucleotides, except thymidine (dT), was acquired from CID of both the LNA gapmer and mixmer ions. On the other hand, extensive fragmentation from various dissociation channels was observed from post-ion/ion ion trap CID of the higher charge state ions of both LNA-DNA chimeras. This report demonstrates that tandem mass spectrometry is effective in the sequence characterization of LNA oligonucleotides and LNA-DNA chimeric therapeutics.

  9. Ion Trapping, Storage, and Ejection in Structures for Lossless Ion Manipulations

    SciTech Connect

    Zhang, Xinyu; Garimella, Venkata BS; Prost, Spencer A.; Webb, Ian K.; Chen, Tsung-Chi; Tang, Keqi; Tolmachev, Aleksey V.; Norheim, Randolph V.; Baker, Erin Shammel; Anderson, Gordon A.; Ibrahim, Yehia M.; Smith, Richard D.

    2015-06-16

    A structure for lossless ion manipulation (SLIM) module was constructed with electrode arrays patterned on a pair of parallel printed circuit boards (PCB) separated by 5 mm and utilized to investigate capabilities for ion trapping at 4 Torr. Positive ions were confined by application of RF having alternating phases on a series of inner rung electrodes and by positive DC potentials on surrounding guard electrodes on each PCB. An axial DC field was also introduced by stepwise varying the DC potential of the inner rung electrodes so as to control the ion transport and accumulation inside the ion trap. We show that ions could be trapped and accumulated with 100% efficiency, stored for at least 5 hours with no losses, and could be rapidly ejected from the SLIM trap.

  10. The uses of electron beam ion traps in the study of highly charged ions

    SciTech Connect

    Knapp, D.

    1994-11-02

    The Electron Beam Ion Trap (EBIT) is a relatively new tool for the study of highly charged ions. Its development has led to a variety of new experimental opportunities; measurements have been performed with EBITs using techniques impossible with conventional ion sources or storage rings. In this paper, I will highlight the various experimental techniques we have developed and the results we have obtained using the EBIT and higher-energy Super-EBIT built at the Lawrence Livermore National Laboratory. The EBIT employs a high-current-density electron beam to trap, ionize, and excite a population of ions. The ions can be studied in situ or extracted from the trap for external experiments. The trapped ions form an ionization-state equilibrium determined by the relative ionization and recombination rates. Ions of several different elements may simultaneously be present in the trap. The ions are nearly at rest, and, for most systems, all in their ground-state configurations. The electron-ion interaction energy has a narrow distribution and can be varied over a wide range. We have used the EBIT devices for the measurement of electron-ion interactions, ion structure, ion-surface interactions, and the behavior of low-density plasmas.

  11. Next Generation JPL Ultra-Stable Trapped Ion Atomic Clocks

    NASA Technical Reports Server (NTRS)

    Burt, Eric; Tucker, Blake; Larsen, Kameron; Hamell, Robert; Tjoelker, Robert

    2013-01-01

    Over the past decade, trapped ion atomic clock development at the Jet Propulsion Laboratory (JPL) has focused on two directions: 1) new atomic clock technology for space flight applications that require strict adherence to size, weight, and power requirements, and 2) ultra-stable atomic clocks, usually for terrestrial applications emphasizing ultimate performance. In this paper we present a new ultra-stable trapped ion clock designed, built, and tested in the second category. The first new standard, L10, will be delivered to the Naval Research Laboratory for use in characterizing DoD space clocks.

  12. Scalable Implementation of Boson Sampling with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Shen, C.; Zhang, Z.; Duan, L.-M.

    2014-02-01

    Boson sampling solves a classically intractable problem by sampling from a probability distribution given by matrix permanents. We propose a scalable implementation of boson sampling using local transverse phonon modes of trapped ions to encode the bosons. The proposed scheme allows deterministic preparation and high-efficiency readout of the bosons in the Fock states and universal mode mixing. With the state-of-the-art trapped ion technology, it is feasible to realize boson sampling with tens of bosons by this scheme, which would outperform the most powerful classical computers and constitute an effective disproof of the famous extended Church-Turing thesis.

  13. A model of optical trapping cold atoms using a metallic nano wire with surface plasmon effect

    NASA Astrophysics Data System (ADS)

    Thi Phuong Lan, Nguyen; Thi Nga, Do; Viet, Nguyen Ai

    2016-06-01

    In this work, we construct a new model of optical trapping cold atoms with a metallic nano wire by using surface plasmon effect generated by strong field of laser beams. Using the skin effect, we send a strong oscillated electromagnetic filed through the surface of a metallic nano wire. The local field generated by evanescent effect creates an effective attractive potential near the surface of metallic nano wires. The consideration of some possible boundary and frequency conditions might lead to non-trivial bound state solution for a cold atom. We discus also the case of the laser reflection optical trap with shell-core design, and compare our model with another recent schemes of cold atom optical traps using optical fibers and carbon nanotubes.

  14. "Fast excitation" CID in a quadrupole ion trap mass spectrometer.

    PubMed

    Murrell, J; Despeyroux, D; Lammert, S A; Stephenson, J L; Goeringer, D E

    2003-07-01

    Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. "Fast excitation" CID deposits (as determined by the intensity ratio of the a(4)/b(4) ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with "fast excitation" CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for "fast excitation" CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M + 17H)(17+) of horse heart myoglobin is also shown to illustrate the application of "fast excitation" CID to proteins.

  15. "Fast Excitation" CID in Quadrupole Ion Trap Mass Spectrometer

    SciTech Connect

    Murrell, J.; Despeyroux, D.; Lammert, Stephen {Steve} A; Stephenson Jr, James {Jim} L; Goeringer, Doug

    2003-01-01

    Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. ''Fast excitation'' CID deposits (as determined by the intensity ratio of the a{sub 4}/b{sub 4} ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with ''fast excitation'' CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for ''fast excitation'' CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M + 17H){sup 17+} of horse heart myoglobin is also shown to illustrate the application of ''fast excitation'' CID to proteins.

  16. Electron Cooling of Highly Charged Ions in Penning Traps

    SciTech Connect

    Zwicknagel, Guenter

    2006-10-18

    For recent and planned experiments like the CPT-tests with antihydrogen at CERN (ATHENA, ATRAP) or the QED-tests and various other investigations with slow highly charged ions at GSI (HTTRAP), the ions or antiprotons are cooled with electrons or positrons in Penning traps. In many of these applications an efficient and fast cooling is crucial. In particular for electron cooling of highly charged ions, like e.g. of U92+ in HITRAP, sufficiently large cooling rates are mandatory for avoiding too much losses by recombination or charge exchange processes. Here we present calculations of electron cooling and recombination losses of an ensemble of ions in a Penning traps based on a detailed description of the cooling force and the actual radiative ion-electron recombination rate. We focus on the cooling of highly charged ions, namely bare Uranium, in HITRAP. Both the associated cooling times and recombination losses strongly depend on the density of the electrons and the ratio of the number of ions to the number of electrons in the trap. Our analysis shows that electron cooling of bare Uranium with an initial energy of a few keV/u is feasible with a cooling time less than about a second at less than 10 percent recombination losses.

  17. Enhanced Light Collection from a Trapped Ion Using a Micromirror Integrated with Surface Trap

    NASA Astrophysics Data System (ADS)

    Noek, Rachel; Knoernschild, Caleb; Kim, Taehyun; Maunz, Peter; Merrill, True; Hayden, Harley; Pai, C. S.; Kim, Jungsang

    2010-03-01

    Efficient collection of fluorescence from trapped atoms or ions is imperative for high speed, high fidelity quantum information processing. Using low f-number conventional collection optics, less than 7% of light can be collected from a small field of view (FoV, <0.2mm). We add high numerical aperture micromirrors behind each point source, and image the reflected light from the micromirrors with a conventional f/2.55 imaging system and obtain a factor of 18 improvement in collection over the same system without the micromirrors. The FoV expands to 17.8 mm and the numerical aperture is limited by the micromirror behind the ion rather than the conventional optics. We used a fluorescent microbead mounted on a glass pipette and a custom fabricated 100 um diameter Al coated Si micromirror to demonstrate this principle. Micromirrors integrated with surface ion traps are currently under development for improved ion detection and FoV.

  18. Mobility-Selected Ion Trapping and Enrichment Using Structures for Lossless Ion Manipulations

    DOE PAGES

    Chen, Tsung-Chi; Ibrahim, Yehia M.; Webb, Ian K.; Garimella, Sandilya V. B.; Zhang, Xing; Hamid, Ahmed M.; Deng, Liulin; Karnesky, William E.; Prost, Spencer A.; Sandoval, Jeremy A.; et al

    2016-01-11

    The integration of ion mobility spectrometry (IMS) with mass spectrometry (MS) and the ability to trap ions in IMS-MS measurements is of great importance for performing reactions, accumulating ions, and increasing analytical measurement sensitivity. The development of Structures for Lossless Ion Manipulations (SLIM) offers the potential for ion manipulations in a more reliable and cost-effective manner, while opening opportunities for much more complex sequences of manipulations. Here, we demonstrate an ion separation and trapping module and a method based upon SLIM that consists of a linear mobility ion drift region, a switch/tee and a trapping region that allows the isolationmore » and accumulation of mobility-separated species. The operation and optimization of the SLIM switch/tee and trap are described and demonstrated for the enrichment of the low abundance ions. Lastly, we observed a linear increase in ion intensity with the number of trapping/accumulation events using the SLIM trap, illustrating its potential for enhancing the sensitivity of low abundance or targeted species.« less

  19. A System For High Flexibility Entangling Gates With Trapped Ions

    NASA Astrophysics Data System (ADS)

    Milne, Alistair; Edmunds, Claire; Mavadia, Sandeep; Green, Todd; Biercuk, Michael

    Trapped ion qubits may be entangled via coupling to shared modes of motion using spin-dependent forces generated by optical fields. Residual qubit-motional coupling at the conclusion of the entangling operation is the dominant source of infidelity in this type of gate. For synchronously entangling increasing numbers of ions, longer gate times are required to minimise this residual coupling. We present a scheme that enables the state of each qubit to be simultaneously decoupled from all motional modes in an arbitrarily chosen gate time, increasing the gate fidelity and scalability. This is achieved by implementing discrete phase shifts in the optical field moderating the entangling operation. We describe an experimental system based on trapped ytterbium ions and demonstrate this scheme for two-qubit entangling gates on ytterbium ion pairs.

  20. Memory coherence of a sympathetically cooled trapped-ion qubit

    NASA Astrophysics Data System (ADS)

    Home, J. P.; McDonnell, M. J.; Szwer, D. J.; Keitch, B. C.; Lucas, D. M.; Stacey, D. N.; Steane, A. M.

    2009-05-01

    We demonstrate sympathetic cooling of a C43a+ trapped-ion “memory” qubit by a C40a+ “coolant” ion sufficiently near the ground state of motion for fault-tolerant quantum logic, while maintaining coherence of the qubit. This is an essential ingredient in trapped-ion quantum computers. The isotope shifts are sufficient to suppress decoherence and phase shifts of the memory qubit due to the cooling light which illuminates both ions. We measure the qubit coherence during ten cycles of sideband cooling, finding a coherence loss of 3.3% per cooling cycle. The natural limit of the method is O(10-4) infidelity per cooling cycle.

  1. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    NASA Astrophysics Data System (ADS)

    Montoya, Cris; Valencia, Jose; Geraci, Andrew A.; Eardley, Matthew; Moreland, John; Hollberg, Leo; Kitching, John

    2015-06-01

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a microcantilever with a magnetic tip. The cantilever is mounted on a multilayer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman-state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, and precision sensing.

  2. Characterization of protonated phospholipids as fragile ions in quadrupole ion trap mass spectrometry

    PubMed Central

    Garrett, Timothy J.; Merves, Matthew; Yost, Richard A.

    2011-01-01

    Some ions exhibit “ion fragility” in quadrupole ion trap mass spectrometry (QIT-MS) during mass analysis with resonance ejection. In many cases, different ions generated from the same compound exhibit different degrees of ion fragility, with some ions (e.g., the [M+H]+ ion) stable and other ions (e.g., the [M+Na]+ ion) fragile. The ion fragility for quadrupole ion trap (QIT) mass spectrometry (MS) for protonated and sodiated ions of three phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, PC (16:0/16:0), 1,2-dipalmitoyl-sn-glycero-3-phophoethanolamine, PE (16:0/16:0), and N-palmitoyl-D-erythro-sphingosylphosphorylcholine, SM (d18:1/16:0), was determined using three previously developed experiments: 1) the peak width using a slow scan speed, 2) the width of the isolation window for efficient isolation, and 3) the energy required for collision-induced dissociation. In addition, ion fragility studies were designed and performed to explore a correlation between ion fragility in QIT mass analysis and ion fragility during transport between the ion source and the ion trap. These experiments were: 1) evaluating the amount of thermal-induced dissociation as a function of heated capillary temperature, and 2) determining the extent of fragmentation occurring with increasing tube lens voltage. All phospholipid species studied exhibited greater ion fragility as protonated species in ion trap mass analysis than as sodiated species. In addition, the protonated species of both SM (d18:0/16:0) and PC (16:0/16:0) exhibited greater tendencies to fragment at higher heated capillary temperatures and high tube lens voltages, whereas the PE (16:0/16:0) ions did not appear to exhibit fragility during ion transport. PMID:22247650

  3. A Modular Quantum System of Trapped Atomic Ions

    NASA Astrophysics Data System (ADS)

    Hucul, David Alexander

    Scaling up controlled quantum systems to involve large numbers of qubits remains one of the outstanding challenges of quantum information science. One path toward scalability is the use of a modular architecture where adjacent qubits may be entangled with applied electromagnetic fields, and remote qubits may be entangled using photon interference. Trapped atomic ion qubits are one of the most promising platforms for scaling up quantum systems by combining long coherence times with high fidelity entangling operations between proximate and remote qubits. In this thesis, I present experimental progress on combining entanglement between remote atomic ions separated by 1 meter with near-field entanglement between atomic ions in the same ion trap. I describe the experimental improvements to increase the remote entanglement rate by orders of magnitude to nearly 5 per second. This is the first experimental demonstration where the remote entanglement rate exceeds the decoherence rate of the entangled qubits. The flexibility of creating remote entanglement through photon interference is demonstrated by using the interference of distinguishable photons without sacrificing remote entanglement rate or fidelity. Next I describe the use of master clock in combination with a frequency comb to lock the phases of all laser-induced interactions between remote ion traps while removing optical phase stability requirements. The combination of both types of entanglement gates to create a small quantum network are described. Finally, I present ways to mitigate cross talk between photonic and memory qubits by using different trapped ion species. I show preliminary work on performing state detection of nuclear spin 0 ions by using entanglement between atomic ion spin and photon polarization. These control techniques may be important for building a large-scale modular quantum system.

  4. Improving ion mobility measurement sensitivity by utilizing helium in an ion funnel trap.

    PubMed

    Ibrahim, Yehia M; Garimella, Sandilya V B; Tolmachev, Aleksey V; Baker, Erin S; Smith, Richard D

    2014-06-01

    Ion mobility instruments that utilize nitrogen as buffer gas are often preceded by an ion trap and accumulation region that also uses nitrogen, and for different inert gases, no significant effects upon performance are expected for ion mobility spectrometry (IMS) of larger ions. However, we have observed significantly improved performance for an ion funnel trap upon adding helium; the signal intensities for higher m/z species were improved by more than an order of magnitude compared to using pure nitrogen. The effect of helium upon IMS resolving power was also studied by introducing a He/N2 gas mixture into the drift cell, and in some cases, a slight improvement was observed compared to pure N2. The improvement in signal can be largely attributed to faster and more efficient ion ejection into the drift tube from the ion funnel trap.

  5. Field-free junctions for surface electrode ion traps

    NASA Astrophysics Data System (ADS)

    Jordens, Robert; Schmied, R.; Blain, M. G.; Leibfried, D.; Wineland, D.

    2015-05-01

    Intersections between transport guides in a network of RF ion traps are a key ingredient to many implementations of scalable quantum information processing with trapped ions. Several junction architectures demonstrated so far are limited by varying radial secular frequencies, a reduced trap depth, or a non-vanishing RF field along the transport channel. We report on the design and progress in implementing a configurable microfabricated surface electrode Y-junction that employs switchable RF electrodes. An essentially RF-field-free pseudopotential guide between any two legs of the junction can be established by applying RF potential to a suitable pair of electrodes. The transport channel's height above the electrodes, its depth and radial curvature are constant to within 15%. Supported by IARPA, Sandia, NSA, ONR, and the NIST Quantum Information Program.

  6. Verification of high efficient broad beam cold cathode ion source

    NASA Astrophysics Data System (ADS)

    Abdel Reheem, A. M.; Ahmed, M. M.; Abdelhamid, M. M.; Ashour, A. H.

    2016-08-01

    An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.

  7. Verification of high efficient broad beam cold cathode ion source.

    PubMed

    Abdel Reheem, A M; Ahmed, M M; Abdelhamid, M M; Ashour, A H

    2016-08-01

    An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition. PMID:27587108

  8. Dual-Ion-Trap Frequency Standards With Overlapping Cycles

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Prestage, John D.

    1992-01-01

    Proposed scheme for enhancing performances of atomic frequency-standard apparatuses calls for two or more ion traps per apparatus interrogated in alternation by radio-frequency pulses. Provides nearly constant feedback gain, thereby providing nearly constant corrections for fluctuations in frequency of local oscillator. Degradation of performance by fluctuations in local oscillators reduced.

  9. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    SciTech Connect

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  10. Criteria for ultrastable operation of the trapped ion frequency standard

    NASA Technical Reports Server (NTRS)

    Tjoelker, R. L.; Prestage, J. D.; Maleki, L.

    1992-01-01

    The leading systematic perturbations to the Jet Propulsion Laboratory's (JPL's) mercury trapped ion frequency standard are characterized under present operating conditions. Sensitivity of the standard to environmental variations is measured, and the required regulation of key components to obtain a stability of 10(exp -16) is identified.

  11. Enabling Technologies for Scalable Trapped Ion Quantum Computing

    NASA Astrophysics Data System (ADS)

    Crain, Stephen; Gaultney, Daniel; Mount, Emily; Knoernschild, Caleb; Baek, Soyoung; Maunz, Peter; Kim, Jungsang

    2013-05-01

    Scalability is one of the main challenges of trapped ion based quantum computation, mainly limited by the lack of enabling technologies needed to trap, manipulate and process the increasing number of qubits. Microelectromechanical systems (MEMS) technology allows one to design movable micromirrors to focus laser beams on individual ions in a chain and steer the focal point in two dimensions. Our current MEMS system is designed to steer 355 nm pulsed laser beams to carry out logic gates on a chain of Yb ions with a waist of 1.5 μm across a 20 μm range. In order to read the state of the qubit chain we developed a 32-channel PMT with a custom read-out circuit operating near the thermal noise limit of the readout amplifier which increases state detection fidelity. We also developed a set of digital to analog converters (DACs) used to supply analog DC voltages to the electrodes of an ion trap. We designed asynchronous DACs to avoid added noise injection at the update rate commonly found in synchronous DACs. Effective noise filtering is expected to reduce the heating rate of a surface trap, thus improving multi-qubit logic gate fidelities. Our DAC system features 96 channels and an integrated FPGA that allows the system to be controlled in real time. This work was supported by IARPA/ARO.

  12. From transistor to trapped-ion computers for quantum chemistry.

    PubMed

    Yung, M-H; Casanova, J; Mezzacapo, A; McClean, J; Lamata, L; Aspuru-Guzik, A; Solano, E

    2014-01-01

    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. PMID:24395054

  13. Quantum Simulation of Quantum Field Theories in Trapped Ions

    SciTech Connect

    Casanova, J.; Lamata, L.; Egusquiza, I. L.; Gerritsma, R.; Roos, C. F.; Garcia-Ripoll, J. J.; Solano, E.

    2011-12-23

    We propose the quantum simulation of fermion and antifermion field modes interacting via a bosonic field mode, and present a possible implementation with two trapped ions. This quantum platform allows for the scalable add up of bosonic and fermionic modes, and represents an avenue towards quantum simulations of quantum field theories in perturbative and nonperturbative regimes.

  14. a Continuous Supersonic Expansion Discharge Nozzle for Rotationally Cold Ions

    NASA Astrophysics Data System (ADS)

    Kauffman, Carrie A.; Crabtree, Kyle N.; McCall, Benjamin J.

    2009-06-01

    Molecular ions play an important role in chemistry and astronomy. In particular, molecular ions are key reaction intermediates, and in the interstellar medium, where temperatures and densities are low, they dominate the chemistry. Studying these ions spectroscopically in the laboratory poses a difficult challenge due to their reactivity. In our effort to study molecular ions, our research group is building SCRIBES (Sensitive Cooled Resolved Ion BEam Spectroscopy), which combines a cold ion source, mass spectrometry, and cavity ring-down spectroscopy. With this apparatus, we will be able to record rotationally-resolved gas-phase spectra, enabling interstellar searches for these species. The SCRIBES instrument requires a source of rotationally cold ions, and this has been accomplished by coupling a supersonic expansion with an electric discharge. Other groups (e.g. Thaddeus and McCarthy at Harvard, Salama et. al at NASA-Ames) have produced cold ions in a similar fashion, but always with a pulsed discharge source. Due to our need for a continuous ion source for SCRIBES, we have designed a continuous supersonic expansion discharge nozzle. We will discuss the various design factors considered during the construction of our continuous self-aligning cold ion source.

  15. Quantum energy teleportation with trapped ions

    SciTech Connect

    Hotta, Masahiro

    2009-10-15

    We analyze a protocol of quantum energy teleportation that transports energy from the left edge of a linear ion crystal to the right edge by local operations and classical communication at a speed considerably greater than the speed of a phonon in the crystal. A probe qubit is strongly coupled with phonon fluctuation in the ground state for a short time and it is projectively measured in order to obtain information about this phonon fluctuation. During the measurement process, phonons are excited by the time-dependent measurement interaction and the energy of the excited phonons must be infused from outside the system. The obtained information is transferred to the right edge of the crystal through a classical channel. Even though the phonons excited at the left edge do not arrive at the right edge at the same time as when the information arrives at the right edge, we are able to soon extract energy from the ions at the right edge by using the transferred information. Because the intermediate ions of the crystal are not excited during the execution of the protocol, energy is transmitted in the energy-transfer channel without heat generation.

  16. Fluorescence Imaging for Visualization of the Ion Cloud in a Quadrupole Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Talbot, Francis O.; Sciuto, Stephen V.; Jockusch, Rebecca A.

    2013-12-01

    Laser-induced fluorescence is used to visualize populations of gaseous ions stored in a quadrupole ion trap (QIT) mass spectrometer. Presented images include the first fluorescence image of molecular ions collected under conditions typically used in mass spectrometry experiments. Under these "normal" mass spectrometry conditions, the radial ( r) and axial ( z) full-width at half maxima (FWHM) of the detected ion cloud are 615 and 214 μm, respectively, corresponding to ~6 % of r 0 and ~3 % of z 0 for the QIT used. The effects on the shape and size of the ion cloud caused by varying the pressure of helium bath gas, the number of trapped ions, and the Mathieu parameter q z are visualized and discussed. When a "tickle voltage" is applied to the exit end-cap electrode, as is done in collisionally activated dissociation, a significant elongation in the axial, but not the radial, dimension of the ion cloud is apparent. Finally, using spectroscopically distinguishable fluorophores of two different m/ z values, images are presented that illustrate stratification of the ion cloud; ions of lower m/ z (higher q z ) are located in the center of the trapping region, effectively excluding higher m/ z (lower q z ) ions, which form a surrounding layer. Fluorescence images such as those presented here provide a useful reference for better understanding the collective behavior of ions in radio frequency (rf) trapping devices and how phenomena such as collisions and space-charge affect ion distribution.

  17. Octupole Excitation of Trapped Ion Motion for Precision Mass Measurements

    NASA Astrophysics Data System (ADS)

    Bollen, G.; Ringle, R.; Schury, P.; Schwarz, S.; Sun, T.

    2005-04-01

    National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA An azimuthal octupole radiofrequency field has been used to excite the ion motion of ^40Ar^+ ions stored in a Penning trap. A resonant response was observed at twice the ions' true cyclotron frequency φc=q/m.B. The experiment has been performed with the 9.4-T Penning trap system of the recently commissioned LEBIT facility at the NSCL at MSU [1]. Similar to the excitation with an azimuthal quadrupole field at φc [2,3], octupole excitation at 2φc gives rise to a periodic beating of the ion motion between magnetron and reduced cyclotron motion. Differences are observed in the dependence of the excited ion motion on initial amplitudes and phases of the radial eigen motions. The observed behavior of the ions is found to be in good agreement with the results of numerical simulations. The technique still requires further testing but the first results indicate that 2φc excitation may provide benefits that are similar to doubling the magnetic field strength B. In particular precision mass measurements of short-lived rare isotopes may benefit from this technique by being able to reach a given precision with shorter ion storage and observation times. [1] S. Schwarz et al, Nucl. Instr. Meth. B204 (2004) 507 [2] G. Bollen et al., J. Appl. Phys. 68 (1990) 4355 [3] M. König et al., Int. J. Mass Spec. Ion. Proc. 142 (1995) 95

  18. Towards ultra-cold Bose-Fermi mixtures in a micro-magnetic trap

    NASA Astrophysics Data System (ADS)

    Aubin, S.

    2005-05-01

    We present progress on producing quantum degenerate fermionic potassium (^40K) and bosonic rubidium (^87Rb) gases in a micro-magnetic chip trap. The two atomic species are cooled and trapped simultaneously in a vapor loaded magneto-optical trap (MOT). The cold two-species atomic cloud is transported in a quadrupole magnetic trap to the surface of a chip, where it is loaded into a micro-magnetic trap. In optimizing the loading process, we developed an optical probe with high signal-to-noise for mapping out the minima of the micro-magnetic field by creating a 1D MOT at the surface of the chip. We have seen evidence of RF evaporation and are working towards quantum degeneracy. This approach to degeneracy requires only a single chamber, because the rapid evaporative cooling due to the tight confinement of the chip trap relaxes the stringent vacuum requirements of a traditional magnetic trap. In describing our experimental approach, we address the experimental challenges related to microtrapping fermions and future studies of cold Fermi gases. Work supported by NSERC, CFI, PRO, and OIT.

  19. Rapid crystallization of externally produced ions in a Penning trap

    NASA Astrophysics Data System (ADS)

    Murböck, T.; Schmidt, S.; Birkl, G.; Nörtershäuser, W.; Thompson, R. C.; Vogel, M.

    2016-10-01

    We have studied the cooling dynamics, formation process, and geometric structure of mesoscopic crystals of externally produced magnesium ions in a Penning trap. We present a cooling model and measurements for a combination of buffer gas cooling and laser cooling which has been found to reduce the ion kinetic energy by eight orders of magnitude from several hundreds of eV to μ eV and below within seconds. With ion numbers of the order of 1 ×103 to 1 ×105 , such cooling leads to the formation of ion Coulomb crystals which display a characteristic shell structure in agreement with the theory of non-neutral plasmas. We show the production and characterization of two-species ion crystals as a means of sympathetic cooling of ions lacking a suitable laser-cooling transition.

  20. Klein tunneling and Dirac potentials in trapped ions

    SciTech Connect

    Casanova, J.; Garcia-Ripoll, J. J.; Gerritsma, R.; Roos, C. F.; Solano, E.

    2010-08-15

    We propose the quantum simulation of the Dirac equation with potentials, allowing the study of relativistic scattering and Klein tunneling. This quantum relativistic effect permits a positive-energy Dirac particle to propagate through a repulsive potential via the population transfer to negative-energy components. We show how to engineer scalar, pseudoscalar, and other potentials in the 1+1 Dirac equation by manipulating two trapped ions. The Dirac spinor is represented by the internal states of one ion, while its position and momentum are described by those of a collective motional mode. The second ion is used to build the desired potentials with high spatial resolution.

  1. Ultra-stable Hg(+) trapped ion frequency standard

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Tjoelker, R. L.; Dick, G. J.; Maleki, L.

    1992-01-01

    We report the development of a fieldable frequency standard based on Hg-199(+) ions confined in a hybrid r.f./dc linear ion trap. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the r.f. confining fields. A 160 mHz wide atomic resonance line for the 40.5 GHz clock transition is used to steer the output of a 5 MHz crystal oscillator to obtain a stability of 2 x 10 exp -15 for 24,000 s averaging times. For longer averaging intervals, measurements are limited by instabilities in available hydrogen maser frequency standards. Measurements with 37 mHz linewidth for the Hg(+) clock transition demonstrate that the inherent stability for this frequency standard is at least as good as 1 x 10 exp -15.

  2. β-delayed neutron spectroscopy using trapped radioactive ions.

    PubMed

    Yee, R M; Scielzo, N D; Bertone, P F; Buchinger, F; Caldwell, S; Clark, J A; Deibel, C M; Fallis, J; Greene, J P; Gulick, S; Lascar, D; Levand, A F; Li, G; Norman, E B; Pedretti, M; Savard, G; Segel, R E; Sharma, K S; Sternberg, M G; Van Schelt, J; Zabransky, B J

    2013-03-01

    A novel technique for β-delayed neutron spectroscopy has been demonstrated using trapped ions. The neutron-energy spectrum is reconstructed by measuring the time of flight of the nuclear recoil following neutron emission, thereby avoiding all the challenges associated with neutron detection, such as backgrounds from scattered neutrons and γ rays and complicated detector-response functions. (137)I(+) ions delivered from a (252)Cf source were confined in a linear Paul trap surrounded by radiation detectors, and the β-delayed neutron-energy spectrum and branching ratio were determined by detecting the β(-) and recoil ions in coincidence. Systematic effects were explored by determining the branching ratio three ways. Improvements to achieve higher detection efficiency, better energy resolution, and a lower neutron-energy threshold are proposed. PMID:23496704

  3. Scalable digital hardware for a trapped ion quantum computer

    NASA Astrophysics Data System (ADS)

    Mount, Emily; Gaultney, Daniel; Vrijsen, Geert; Adams, Michael; Baek, So-Young; Hudek, Kai; Isabella, Louis; Crain, Stephen; van Rynbach, Andre; Maunz, Peter; Kim, Jungsang

    2015-09-01

    Many of the challenges of scaling quantum computer hardware lie at the interface between the qubits and the classical control signals used to manipulate them. Modular ion trap quantum computer architectures address scalability by constructing individual quantum processors interconnected via a network of quantum communication channels. Successful operation of such quantum hardware requires a fully programmable classical control system capable of frequency stabilizing the continuous wave lasers necessary for loading, cooling, initialization, and detection of the ion qubits, stabilizing the optical frequency combs used to drive logic gate operations on the ion qubits, providing a large number of analog voltage sources to drive the trap electrodes, and a scheme for maintaining phase coherence among all the controllers that manipulate the qubits. In this work, we describe scalable solutions to these hardware development challenges.

  4. A high-performance Hg(+) trapped ion frequency standard

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Tjoelker, R. L.; Dick, G. J.; Maleki, L.

    1992-01-01

    A high-performance frequency standard based on (199)Hg(+) ions confined in a hybrid radio frequency (RF)/dc linear ion trap is demonstrated. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. A 160-mHz-wide atomic resonance line for the 40.5-GHz clock transition is used to steer the output of a 5-mHz crystal oscillator to obtain a stability of 2 x 10(exp -15) for 24,000-second averaging times. Measurements with a 37-mHz line width for the Hg(+) clock transition demonstrate that the inherent stability for this frequency standard is better than 1 x 10(exp -15) at 10,000-second averaging times.

  5. Ion Trap Array-Based Systems And Methods For Chemical Analysis

    DOEpatents

    Whitten, William B [Oak Ridge, TN; Ramsey, J Michael [Knoxville, TN

    2005-08-23

    An ion trap-based system for chemical analysis includes an ion trap array. The ion trap array includes a plurality of ion traps arranged in a 2-dimensional array for initially confining ions. Each of the ion traps comprise a central electrode having an aperture, a first and second insulator each having an aperture sandwiching the central electrode, and first and second end cap electrodes each having an aperture sandwiching the first and second insulator. A structure for simultaneously directing a plurality of different species of ions out from the ion traps is provided. A spectrometer including a detector receives and identifies the ions. The trap array can be used with spectrometers including time-of-flight mass spectrometers and ion mobility spectrometers.

  6. Development and Analysis of Cold Trap for Use in Fission Surface Power-Primary Test Circuit

    NASA Technical Reports Server (NTRS)

    Wolfe, T. M.; Dervan, C. A.; Pearson, J. B.; Godfroy, T. J.

    2012-01-01

    The design and analysis of a cold trap proposed for use in the purification of circulated eutectic sodium potassium (NaK-78) loops is presented. The cold trap is designed to be incorporated into the Fission Surface Power-Primary Test Circuit (FSP-PTC), which incorporates a pumped NaK loop to simulate in-space nuclear reactor-based technology using non-nuclear test methodology as developed by the Early Flight Fission-Test Facility. The FSP-PTC provides a test circuit for the development of fission surface power technology. This system operates at temperatures that would be similar to those found in a reactor (500-800 K). By dropping the operating temperature of a specified percentage of NaK flow through a bypass containing a forced circulation cold trap, the NaK purity level can be increased by precipitating oxides from the NaK and capturing them within the cold trap. This would prevent recirculation of these oxides back through the system, which may help prevent corrosion.

  7. Selection of Environmentally Friendly Solvents for the Extravehicular Mobility Unit Secondary Oxygen Pack Cold Trap Testing

    NASA Technical Reports Server (NTRS)

    Steele, John; Chullen, Cinda; Morenz, Jesse; Stephenson, Curtis

    2010-01-01

    Freon-113(TradeMark) has been used as a chemistry lab sampling solvent at NASA/JSC for EMU (extravehicular Mobility Unit) SOP (Secondary Oxygen Pack) oxygen testing Cold Traps utilized at the USA (United Space Alliance) Houston facility. Similar testing has occurred at the HSWL (Hamilton Sundstrand Windsor Locks) facility. A NASA Executive Order bans the procurement of all ODS (ozone depleting substances), including Freon-113 by the end of 2009. In order to comply with NASA direction, HSWL began evaluating viable solvents to replace Freon-113 . The study and testing effort to find Freon-113 replacements used for Cold Trap sampling is the subject of this paper. Test results have shown HFE-7100 (a 3M fluorinated ether) to be an adequate replacement for Freon-113 as a solvent to remove and measure the non-volatile residue collected in a Cold Trap during oxygen testing. Furthermore, S-316 (a Horiba Instruments Inc. high molecular weight, non-ODS chlorofluorocarbon) was found to be an adequate replacement for Freon-113 as a solvent to reconstitute non-volatile residue removed from a Cold Trap during oxygen testing for subsequent HC (hydrocarbon) analysis via FTIR (Fourier Transform Infrared Spectroscopy).

  8. MEMS-based arrays of micro ion traps for quantum simulation scaling.

    SciTech Connect

    Berkeland, Dana J.; Blain, Matthew Glenn; Jokiel, Bernhard, Jr.

    2006-11-01

    In this late-start Tier I Seniors Council sponsored LDRD, we have designed, simulated, microfabricated, packaged, and tested ion traps to extend the current quantum simulation capabilities of macro-ion traps to tens of ions in one and two dimensions in monolithically microfabricated micrometer-scaled MEMS-based ion traps. Such traps are being microfabricated and packaged at Sandia's MESA facility in a unique tungsten MEMS process that has already made arrays of millions of micron-sized cylindrical ion traps for mass spectroscopy applications. We define and discuss the motivation for quantum simulation using the trapping of ions, show the results of efforts in designing, simulating, and microfabricating W based MEMS ion traps at Sandia's MESA facility, and describe is some detail our development of a custom based ion trap chip packaging technology that enables the implementation of these devices in quantum physics experiments.

  9. Microsecond pulsed hydrogen/deuterium exchange of electrosprayed ubiquitin ions stored in a linear ion trap.

    PubMed

    Rajabi, Khadijeh

    2015-02-01

    A pulse of D2O vapour on the order of microseconds is allowed to react with the +6 to +9 charge states of ubiquitin confined in a linear ion trap (LIT). Two envelopes of peaks are detected for the ions of ubiquitin, corresponding to the ions that exchange more quickly and more slowly. The deuterium uptake of the protonated sites on ubiquitin ions accounts for the ion population with the fast exchange. The hydrogen/deuterium exchange (HDX) kinetics of ubiquitin ions trapped in the LIT for 200 ms showed comparable structural transitions to those trapped for 300 ms. When ions are trapped for longer, i.e. up to 2000 ms, mainly the slow exchanging ion population is detected. In all experiments the +7 ions exchange the most, suggesting a short distance between the surface protonated sites and nearby charged sites, and concomitantly high accessibility of surface protonated sites towards D2O. The +6 ions are more compact than the +7 ions but have one fewer protonated site, therefore fewer surface availabilities for D2O attack. The data suggest that the +6 ions keep most of their solution-phase contacts intact while the hydrophobic core is slightly interrupted in the +7 ions, possibly due to the exposure of charged His68 that is normally buried in the hydrophobic pocket. The +8 and +9 ions have more protonated sites but are less compact than the +7 ions because of Coulombic repulsion, resulting in a larger distance between the protonated sites and the basic sites. The data indicate that the HDX mechanism of ions with the slower exchange corresponding to the second envelope of peaks is primarily governed via a relay mechanism. The results suggest that the pulsed HDX MS method is sampling a population of ubiquitin ions with a similar backbone fold to the solution.

  10. Microsecond pulsed hydrogen/deuterium exchange of electrosprayed ubiquitin ions stored in a linear ion trap.

    PubMed

    Rajabi, Khadijeh

    2015-02-01

    A pulse of D2O vapour on the order of microseconds is allowed to react with the +6 to +9 charge states of ubiquitin confined in a linear ion trap (LIT). Two envelopes of peaks are detected for the ions of ubiquitin, corresponding to the ions that exchange more quickly and more slowly. The deuterium uptake of the protonated sites on ubiquitin ions accounts for the ion population with the fast exchange. The hydrogen/deuterium exchange (HDX) kinetics of ubiquitin ions trapped in the LIT for 200 ms showed comparable structural transitions to those trapped for 300 ms. When ions are trapped for longer, i.e. up to 2000 ms, mainly the slow exchanging ion population is detected. In all experiments the +7 ions exchange the most, suggesting a short distance between the surface protonated sites and nearby charged sites, and concomitantly high accessibility of surface protonated sites towards D2O. The +6 ions are more compact than the +7 ions but have one fewer protonated site, therefore fewer surface availabilities for D2O attack. The data suggest that the +6 ions keep most of their solution-phase contacts intact while the hydrophobic core is slightly interrupted in the +7 ions, possibly due to the exposure of charged His68 that is normally buried in the hydrophobic pocket. The +8 and +9 ions have more protonated sites but are less compact than the +7 ions because of Coulombic repulsion, resulting in a larger distance between the protonated sites and the basic sites. The data indicate that the HDX mechanism of ions with the slower exchange corresponding to the second envelope of peaks is primarily governed via a relay mechanism. The results suggest that the pulsed HDX MS method is sampling a population of ubiquitin ions with a similar backbone fold to the solution. PMID:25553956

  11. Double well potentials and quantum phase transitions in ion traps.

    PubMed

    Retzker, A; Thompson, R C; Segal, D M; Plenio, M B

    2008-12-31

    We demonstrate that the radial degree of freedom of strings of trapped ions in the quantum regime may be prepared and controlled accurately through the variation of the external trapping potential while at the same time its properties are measurable with high spatial and temporal resolution. This provides a new testbed giving access to static and dynamical properties of the physics of quantum-many-body systems and quantum phase transitions that are hard to simulate on classical computers. Furthermore, it allows for the creation of double well potentials with experimentally accessible tunneling rates, with applications in testing the foundations of quantum physics and precision sensing. PMID:19437628

  12. Electron beam ion source and electron beam ion trap (invited)a)

    NASA Astrophysics Data System (ADS)

    Becker, Reinard; Kester, Oliver

    2010-02-01

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not "sorcery" but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  13. Ion Isolation in a Linear Ion Trap Using Dual Resonance Frequencies

    NASA Astrophysics Data System (ADS)

    Snyder, Dalton T.; Cooks, R. Graham

    2016-09-01

    Ion isolation in a linear ion trap is demonstrated using dual resonance frequencies, which are applied simultaneously. One frequency is used to eject ions of a broad m/z range higher in m/z than the target ion, and the second frequency is set to eject a range of ions lower in m/z. The combination of the two thus results in ion isolation. Despite the simplicity of the method, even ions of low intensity may be isolated since signal attenuation is less than an order of magnitude in most cases. The performance of dual frequency isolation is demonstrated by isolating individual isotopes of brominated compounds.

  14. The effective temperature of ions stored in a linear quadrupole ion trap mass spectrometer.

    PubMed

    Donald, William A; Khairallah, George N; O'Hair, Richard A J

    2013-06-01

    The extent of internal energy deposition into ions upon storage, radial ejection, and detection using a linear quadrupole ion trap mass spectrometer is investigated as a function of ion size (m/z 59 to 810) using seven ion-molecule thermometer reactions that have well characterized reaction entropies and enthalpies. The average effective temperatures of the reactants and products of the ion-molecule reactions, which were obtained from ion-molecule equilibrium measurements, range from 295 to 350 K and do not depend significantly on the number of trapped ions, m/z value, ion trap q z value, reaction enthalpy/entropy, or the number of vibrational degrees of freedom for the seven reactions investigated. The average of the effective temperature values obtained for all seven thermometer reactions is 318 ± 23 K, which indicates that linear quadrupole ion trap mass spectrometers can be used to study the structure(s) and reactivity of ions at near ambient temperature.

  15. Diviner Lunar Radiometer observations of cold traps in the Moon's south polar region.

    PubMed

    Paige, David A; Siegler, Matthew A; Zhang, Jo Ann; Hayne, Paul O; Foote, Emily J; Bennett, Kristen A; Vasavada, Ashwin R; Greenhagen, Benjamin T; Schofield, John T; McCleese, Daniel J; Foote, Marc C; DeJong, Eric; Bills, Bruce G; Hartford, Wayne; Murray, Bruce C; Allen, Carlton C; Snook, Kelly; Soderblom, Laurence A; Calcutt, Simon; Taylor, Fredric W; Bowles, Neil E; Bandfield, Joshua L; Elphic, Richard; Ghent, Rebecca; Glotch, Timothy D; Wyatt, Michael B; Lucey, Paul G

    2010-10-22

    Diviner Lunar Radiometer Experiment surface-temperature maps reveal the existence of widespread surface and near-surface cryogenic regions that extend beyond the boundaries of persistent shadow. The Lunar Crater Observation and Sensing Satellite (LCROSS) struck one of the coldest of these regions, where subsurface temperatures are estimated to be 38 kelvin. Large areas of the lunar polar regions are currently cold enough to cold-trap water ice as well as a range of both more volatile and less volatile species. The diverse mixture of water and high-volatility compounds detected in the LCROSS ejecta plume is strong evidence for the impact delivery and cold-trapping of volatiles derived from primitive outer solar system bodies. PMID:20966246

  16. Diviner lunar radiometer observations of cold traps in the moon's south polar region

    USGS Publications Warehouse

    Paige, D.A.; Siegler, M.A.; Zhang, J.A.; Hayne, P.O.; Foote, E.J.; Bennett, K.A.; Vasavada, A.R.; Greenhagen, B.T.; Schofield, J.T.; McCleese, D.J.; Foote, M.C.; DeJong, E.; Bills, B.G.; Hartford, W.; Murray, B.C.; Allen, C.C.; Snook, K.; Soderblom, L.A.; Calcutt, S.; Taylor, F.W.; Bowles, N.E.; Bandfield, J.L.; Elphic, R.; Ghent, R.; Glotch, T.D.; Wyatt, M.B.; Lucey, P.G.

    2010-01-01

    Diviner Lunar Radiometer Experiment surface-temperature maps reveal the existence of widespread surface and near-surface cryogenic regions that extend beyond the boundaries of persistent shadow. The Lunar Crater Observation and Sensing Satellite (LCROSS) struck one of the coldest of these regions, where subsurface temperatures are estimated to be 38 kelvin. Large areas of the lunar polar regions are currently cold enough to cold-trap water ice as well as a range of both more volatile and less volatile species. The diverse mixture of water and high-volatility compounds detected in the LCROSS ejecta plume is strong evidence for the impact delivery and cold-trapping of volatiles derived from primitive outer solar system bodies.

  17. Addressing single trapped ions for Rydberg quantum logic

    NASA Astrophysics Data System (ADS)

    Bachor, P.; Feldker, T.; Walz, J.; Schmidt-Kaler, F.

    2016-08-01

    We demonstrate the excitation of ions to the Rydberg state 22F by vacuum ultraviolet radiation at a wavelength of 123 nm combined with the coherent manipulation of the optical qubit transition in {}40{{Ca}}+. With a tightly focused beam at 729 nm wavelength we coherently excite a single ion from a linear string into the metastable 3{D}5/2 state before a VUV pulse excites it to the Rydberg state. In combination with ion shuttling in the trap, we extend this approach to the addressed excitation of multiple ions. The coherent initialization as well as the addressed Rydberg excitation are key prerequisites for more complex applications of Rydberg ions in quantum simulation or quantum information processing.

  18. Spectral measurements of few-electron uranium ions produced and trapped in a high-energy electron beam ion trap

    SciTech Connect

    Beiersdorfer, P.

    1994-11-04

    Measurements of 2s{sub l/2}-2p{sub 3/2} electric dipole and 2p{sub 1/2}-2p{sub 3/2} magnetic dipole and electric quadrupole transitions in U{sup 82+} through U{sup 89+} have been made with a high-resolution crystal spectrometer that recorded the line radiation from stationary ions produced and trapped in a high-energy electron beam ion trap. From the measurements we infer {minus}39.21 {plus_minus} 0.23 eV for the QED contribution to the 2s{sub 1/2}-2p{sub 3/2} transition energy of lithiumlike U{sup 89+}. A comparison between our measurements and various computations illustrates the need for continued improvements in theoretical approaches for calculating the atomic structure of ions with two or more electrons in the L shell.

  19. Cryogenic Linear Ion Trap for Large-Scale Quantum Simulations

    NASA Astrophysics Data System (ADS)

    Pagano, Guido; Hess, Paul; Kaplan, Harvey; Birckelbaw, Eric; Hernanez, Micah; Lee, Aaron; Smith, Jake; Zhang, Jiehang; Monroe, Christopher

    2016-05-01

    Ions confined in RF Paul traps are a useful tool for quantum simulation of long-range spin-spin interaction models. As the system size increases, classical simulation methods become incapable of modeling the exponentially growing Hilbert space, necessitating quantum simulation for precise predictions. Current experiments are limited to less than 30 qubits due to collisions with background gas that regularly destroys the ion crystal. We present progress toward the construction of a cryogenic ion trap apparatus, which uses differential cryopumping to reduce vacuum pressure to a level where collisions do not occur. This should allow robust trapping of about 100 ions/qubits in a single chain with long lifetimes. Such a long chain will provide a platform to investigate simultaneously cooling of various vibrational modes and will enable quantum simulations that outperform their classical counterpart. Our apparatus will provide a powerful test-bed to investigate a large variety of Hamiltonians, including spin 1 and spin 1/2 systems with Ising or XY interactions. This work is supported by the ARO Atomic Physics Program, the AFOSR MURI on Quantum Measurement and Verification, the IC Fellowship Program and the NSF Physics Frontier Center at JQI.

  20. Dipole Field Effects on Ion Ejections from a Paul Ion Trap

    NASA Technical Reports Server (NTRS)

    MacAskill, J. A.; Chutjian, A.

    2011-01-01

    Attempts at improving the quality of mass spectra obtained from a Paul trap mass spectrometer prompted an investigation of the effects of additional fields to supplement the primary rf quadrupole trapping field. Reported here are the results of the first in a series of tests that focuses on the application of a single dipole field to augment the trapping and subsequent ejections of ions stored within a Paul trap. Measurements are presented for a fixed quadrupole frequency with varying dipole frequencies. The presence of the dipole field during the quadrupole trapping phase causes ion ejections of single m/z species at discrete dipole frequencies. During the mass analysis phase, the varying dipole frequency produces a complex set of resonant structures that impact ejection time (mass range), as well as mass spectral peak intensity and width

  1. Design, microfabrication, and analysis of micrometer-sized cylindrical ion trap arrays.

    PubMed

    Cruz, D; Chang, J P; Fico, M; Guymon, A J; Austin, D E; Blain, M G

    2007-01-01

    A description of the design and microfabrication of arrays of micrometer-scale cylindrical ion traps is offered. Electrical characterization and initial ion trapping experiments with a massively parallel array of 5 microm internal radius (r(0)) sized cylindrical ion traps (CITs) are also described. The ion trap, materials, and design are presented and shown to be critical in achieving minimal trapping potential while maintaining minimal power consumption. The ion traps, fabricated with metal electrodes, have inner radii of 1, 2, 5, and 10 microm and range from 5 to 24 microm in height. The electrical characteristics of packaged ion trap arrays were measured with a vector network analyzer. The testing focused on trapping toluene (C(7)H(8)), mass 91, 92, or 93 amu, in the 5 microm sized CITs. Ions were formed via electron impact ionization and were ejected by turning off the rf voltage applied to the ring electrode; a current signal was collected at this time. Optimum ionization and trapping conditions, such as a sufficient pseudopotential well and high ionization to ion loss rate ratio (as determined by simulation), proved to be difficult to establish due to the high device capacitance and the presence of exposed dielectric material in the trapping region. However, evidence was obtained suggesting the trapping of ions in 1%-15% of the traps in the array. These first tests on micrometer-scale CITs indicated the necessary materials and device design modifications for realizing ultrasmall and low power ion traps.

  2. Quantum-enhanced deliberation of learning agents using trapped ions

    NASA Astrophysics Data System (ADS)

    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.

  3. Electromagnetic two-dimensional analysis of trapped-ion eigenmodes

    SciTech Connect

    Kim, D.; Rewoldt, G.

    1984-11-01

    A two-dimensional electromagnetic analysis of the trapped-ion instability for the tokamak case with ..beta.. not equal to 0 has been made, based on previous work in the electrostatic limit. The quasineutrality condition and the component of Ampere's law along the equilibrium magnetic field are solved for the perturbed electrostatic potential and the component of the perturbed vector potential along the equilibrium magnetic field. The general integro-differential equations are converted into a matrix eigenvalue-eigenfunction problem by expanding in cubic B-spline finite elements in the minor radius and in Fourier harmonics in the poloidal angle. A model MHD equilibrium with circular, concentric magnetic surfaces and large aspect ratio is used which is consistent with our assemption that B << 1. The effect on the trapped-ion mode of including these electromagnetic extensions to the calculation is considered, and the temperature (and ..beta..) scaling of the mode frequency is shown and discussed.

  4. A New Trapped Ion Clock Based on Hg-201(+)

    NASA Technical Reports Server (NTRS)

    Taghavi-Larigani, S.; Burt, E. A.; Lea, S. N.; Prestage, J. D.; Tjoelker, R. L.

    2009-01-01

    There are two stable odd isotopes of mercury with singly ionized hyperfine structure suitable for a microwave clock: Hg-199(+) and Hg-201(+). Virtually all trapped mercury ion clocks to date have used the 199 isotope. We have begun to investigate the viability of a trapped ion clock based on Hg-201(+). We have measured the unperturbed frequency of the (S-2)(sub 1/2) F = 1, m(sub F) = 0 to (S-2)(sub 1/2) F = 2, m(sub F) = 0 clock transition to be 29.9543658211(2) GHz. In this paper we describe initial measurements with Hg-201(+) and new applications to clocks and fundamental physics.

  5. Simple implementation of a quantum search with trapped ions

    NASA Astrophysics Data System (ADS)

    Ivanov, Svetoslav S.; Ivanov, Peter A.; Vitanov, Nikolay V.

    2008-09-01

    We propose an ion-trap implementation of Grover’s quantum search algorithm for an unstructured database of arbitrary length N . The experimental implementation is appealingly simple because the linear ion trap allows for a straightforward construction, in a single interaction step and without a multitude of Hadamard transforms, of the reflection operator, which is the engine of the Grover algorithm. Consequently, a dramatic reduction in the number of the required physical steps takes place, to just O(N) , the same as the number of mathematical steps. The proposed setup allows for demonstration of both the original (probabilistic) Grover search and its deterministic variation, and is remarkably robust to imperfections in the register initialization.

  6. Scalable Implementation of Boson Sampling with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Shen, Chao; Zhang, Zhen; Duan, Luming

    2014-03-01

    Boson sampling solves a classically intractable problem by sampling from a probability distribution given by matrix permanents. We propose a scalable implementation of Boson sampling using local transverse phonon modes of trapped ions to encode the Bosons. The proposed scheme allows deterministic preparation and high-efficiency readout of the Bosons in the Fock states and universal mode mixing. With the state-of-the-art trapped ion technology, it is feasible to realize Boson sampling with tens of Bosons by this scheme, which would outperform the most powerful classical computers and constitute an effective disproof of the famous extended Church-Turing thesis. This work was supported by the NBRPC (973 Program) 2011CBA00300 (2011CBA00302), the IARPA MUSIQC program, the ARO and the AFOSR MURI programs, and the DARPA OLE program.

  7. Spectroscopy of Argon Excited in an Electron Beam Ion Trap

    SciTech Connect

    Trabert, E

    2005-04-18

    Argon is one of the gases best investigated and most widely used in plasma discharge devices for a multitude of applications that range from wavelength reference standards to controlled fusion experiments. Reviewing atomic physics and spectroscopic problems in various ionization stages of Ar, the past use and future options of employing an electron beam ion trap (EBIT) for better and more complete Ar data in the x-ray, EUV and visible spectral ranges are discussed.

  8. Simulating quantum Brownian motion with single trapped ions

    SciTech Connect

    Maniscalco, S.; Piilo, J.; Intravaia, F.; Petruccione, F.; Messina, A.

    2004-05-01

    We study the open system dynamics of a harmonic oscillator coupled with an artificially engineered reservoir. We single out the reservoir and system variables governing the passage between Lindblad-type and non-Lindblad-type dynamics of the reduced system's oscillator. We demonstrate the existence of conditions under which virtual exchanges of energy between system and reservoir take place. We propose to use a single trapped ion coupled to engineered reservoirs in order to simulate quantum Brownian motion.

  9. Trapped ion system for for multi-species quantum control

    NASA Astrophysics Data System (ADS)

    Hanneke, David

    2015-05-01

    Many atoms and molecules possess interesting spectroscopic transitions, but lack dissipative transitions useful for control and detection of internal states. In particular, molecules are useful candidates for quantum memories, low-temperature chemistry studies, tests of fundamental symmetries, and searches for time-variation of fundamental constants, but most lack a convenient cycling transition. By co-trapping a molecular ion with an atomic ion, the atom can provide all dissipation and detection. We present a system capable of such quantum control and report progress towards its use. This work is supported by the NSF, the Research Corporation for Science Advancement, and Amherst College.

  10. Ion trap quantum computing with transverse phonon modes

    NASA Astrophysics Data System (ADS)

    Zhu, Shi-Liang; Monroe, Chris; Duan, Luming

    2006-03-01

    We propose a scheme to use the transverse modes to implement conditional phase gates on two trapped ions immersed in a large linear crystal of ions, without the sideband addressing. Comparing with the conventional approach using the longitudinal modes, with the cost that the laser power is slightly stronger, the proposed gate operation can be well inside Lamb-Dicke region and the gate infidelity due to the fluctuation of the effective Rabi frequency as well as the fundamental limits of the cooling procedure are approximately two orders smaller.

  11. In situ observations of "cold trap" dehydration in the western tropical Pacific

    NASA Astrophysics Data System (ADS)

    Hasebe, F.; Fujiwara, M.; Nishi, N.; Shiotani, M.; Vömel, H.; Oltmans, S.; Takashima, H.; Saraspriya, S.; Komala, N.

    2006-07-01

    Water vapor sonde observations were conducted at Bandung, Indonesia (6.90 S, 107.60 E) and Tarawa, Kiribati (1.35 N, 172.91 E) in December 2003 to examine the efficiency of the "cold trap'' dehydration in the tropical tropopause layer (TTL). Trajectory analysis based on bundles of trajectories suggest that the modification of air parcels' identity due to irreversible mixing by the branching-out and merging-in of nearby trajectories is found to be an important factor, in addition to the routes air parcels are supposed to follow, for interpreting the water vapor concentrations observed by radiosondes in the TTL. Clear correspondence between the observed water vapor concentration and the estimated temperature history of air parcels is found showing that dry air parcels are exposed to low temperatures while humid air parcels do not experience cold conditions during advection, in support of the "cold trap'' hypothesis. It is suggested that the observed air parcel retained the water vapor by roughly twice as much as the minimum saturation mixing ratio after its passage through the "cold trap,'' although appreciable uncertainties remain.

  12. Connecting trapped ions and quantum dots with photons

    NASA Astrophysics Data System (ADS)

    Koehl, Michael

    Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of an Yb+ ion. We ameliorate the effect of the sixty-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the σz projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum state-transfer in a hybrid photonic network.

  13. Excitation and photo-ionization of ultra-cold potassium atoms in the AC-driven magneto optical trap (AC-MOT)

    NASA Astrophysics Data System (ADS)

    Agomuo, John; Murray, Andrew; Harvey, Matthew

    2014-03-01

    The operation of a new cold atom trap (the AC-MOT) and its application in photoionization experiments is described. Ionization of cold K atoms in the AC-MOT is discussed, the ionization proceeding in a stepwise fashion using a combination of infra-red radiation with that from a blue diode laser. A significant limitation of magneto optical trapping (MOT) techniques has been the requirement to eliminate the magnetic fields prior to the interaction occurring. To address this, the AC-MOT was invented in Manchester. This is a pulsed trap, so that the magnetic fields are completely eliminated prior to the electron interaction. Low energy electrons can then be extracted from laser photoionization. In this work, the potassium is cooled to ~0.25mK. Photoionization proceeds by a stepwise route, atoms excited by the trapping laser at ~766nm being ionized by radiation at ~448nm. Both fluorescence from the atoms and the ion yield are used to determine details of the interaction. These techniques are being studied since it then is possible to create cold electron bunches of high coherence. A detailed description of the AC-MOT, its operation and application will be presented. A new cold electron source being built in Manchester will also be discussed. I wish to acknowledge the financial support from Tertiary Education Trust Fund Nigeria and Nigerian Defence Academy Kaduna.

  14. A new trapped ion atomic clock based on 201Hg+.

    PubMed

    Burt, Eric A; Taghavi-Larigani, Shervin; Tjoelker, Robert L

    2010-03-01

    High-resolution spectroscopy has been performed on the ground-state hyperfine transitions in trapped (201)Hg+ ions as part of a program to investigate the viability of (201)Hg+ for clock applications. Part of the spectroscopy work was directed at magnetic-field-sensitive hyperfine lines with delta m(F) = 0, which allow accurate Doppler-free measurement of the magnetic field experienced by the trapped ions. Although it is possible to measure Doppler-free magnetic-field-sensitive transitions in the commonly used clock isotope, (199)Hg+, it is more difficult. In this paper, we discuss how this (199)Hg+ feature may be exploited to produce a more stable clock or one requiring less magnetic shielding in environments with magnetic field fluctuations far in excess of what is normally found in the laboratory. We have also determined that in discharge-lamp-based trapped mercury ion clocks, the optical pumping time for (201)Hg+ is about 3 times shorter than that of (199)Hg+ This can be used to reduce dead time in the interrogation cycle for these types of clocks, thereby reducing the impact of local oscillator noise aliasing effects.

  15. Absorption mode Fourier transform electrostatic linear ion trap mass spectrometry.

    PubMed

    Hilger, Ryan T; Wyss, Phillip J; Santini, Robert E; McLuckey, Scott A

    2013-09-01

    In Fourier transform mass spectrometry, it is well-known that plotting the spectrum in absorption mode rather than magnitude mode has several advantages. However, magnitude spectra remain commonplace due to difficulties associated with determining the phase of each frequency at the onset of data acquisition, which is required for generating absorption spectra. The phasing problem for electrostatic traps is much simpler than for Fourier transform ion cyclotron resonance (FTICR) instruments, which greatly simplifies the generation of absorption spectra. Here, we present a simple method for generating absorption spectra from a Fourier transform electrostatic linear ion trap mass spectrometer. The method involves time shifting the data prior to Fourier transformation in order to synchronize the onset of data acquisition with the moment of ion acceleration into the electrostatic trap. Under these conditions, the initial phase of each frequency at the onset of data acquisition is zero. We demonstrate that absorption mode provides a 1.7-fold increase in resolution (full width at half maximum, fwhm) as well as reduced peak tailing. We also discuss methodology that may be applied to unsynchronized data in order to determine the time shift required to generate an absorption spectrum.

  16. Ionization of polarized 3He+ ions in EBIS trap with slanted electrostatic mirror.

    SciTech Connect

    Pikin,A.; Zelenski, A.; Kponou, A.; Alessi, J.; Beebe, E.; Prelee, K.; Raparia, D.

    2007-09-10

    Methods of producing the nuclear polarized {sup 3}He{sup +} ions and their ionization to {sup 3}H{sup ++} in ion trap of the electron Beam Ion Source (EBIS) are discussed. Computer simulations show that injection and accumulation of {sup 3}He{sup +} ions in the EBIS trap with slanted electrostatic mirror can be very effective for injection times longer than the ion traversal time through the trap.

  17. MODEL SIMULATIONS OF CONTINUOUS ION INTERJECTION INTO EBIS TRAP WITH SLANTED ELECTROSTATIC MIRROR.

    SciTech Connect

    PIKIN,A.; KPONOU, A.; ALESSI, J.G.; BEEBE, E.N.; PRELEC, K.; RAPARIA, D.

    2007-08-26

    The efficiency of trapping ions in an EBIS is of primary importance for many applications requiring operations with externally produced ions: RIA breeders, ion sources, traps. At the present time, the most popular method of ion injection is pulsed injection, when short bunches of ions get trapped in a longitudinal trap while traversing the trap region. Continuous trapping is a challenge for EBIS devices because mechanisms which reduce the longitudinal ion energy per charge in a trap (cooling with residual gas, energy exchange with other ions, ionization) are not very effective, and accumulation of ions is slow. A possible approach to increase trapping efficiency is to slant the mirror at the end of the trap which is opposite to the injection end. A slanted mirror will convert longitudinal motion of ions into transverse motion, and, by reducing their longitudinal velocity, prevent these ions from escaping the trap on their way out. The trade off for the increased trapping efficiency this way is an increase in the initial transverse energy of the accumulated ions. The slanted mirror can be realized if the ends of two adjacent electrodes- drift tubes - which act as an electrostatic mirror, are machined to produce a slanted gap, rather than an upright one. Applying different voltages to these electrodes will produce a slanted mirror. The results are presented of 2D and 3D computer simulations of ion injection into a simplified model of EBIS with slanted mirror.

  18. Formation and photodetachment of cold metal cluster negative ions

    NASA Astrophysics Data System (ADS)

    Zheng, L.-S.; Brucat, P. J.; Pettiette, C. L.; Yang, S.; Smalley, R. E.

    1985-10-01

    A general method is described for the formation of cold metal cluser negative ion beams which serve as excellent sources for photodetachment experiments. The method involves the pulsed laser vaporization of a metal target at the throat of a pulsed supersonic helium expansion. By the optimization of source conditions, intense beams (greater than 105 ions/pulse) of both positive and negative ions are produced routinely. Ionization of the metal cluster molecules, either during vaporization or by irradiation with 193 nm light, occurs prior to supersonic expansion and produces a cold plasma entrained in the neural flow that is renitent to stray electric and magnetic fields, unlike photoions produced in the collisionless downstream molecular beam. The enhancement of the negative ion flux by 193 nm irradiation is believed to be evidence for efficient electron attachment of low energy photoelectrons generated in the nozzle region. This attachment process, however, is apparently not effective for molecules containing less than ˜4 metal atoms. Laser irradition of mass-selected cluster anions extracted from these cold ion beams reveal that photodetachment of the metal cluster negative ion is always the preferred pathway, even when fragmentation of the ion is possible. This new negative ion production technique should therefore permit measurement of both electron affinities and photoelectron spectra as a function of cluster size and composition.

  19. In situ plasma removal of surface contaminants from ion trap electrodes

    SciTech Connect

    Haltli, Raymond A.

    2015-05-01

    In this thesis, the construction and implementation of an in situ plasma discharge designed to remove surface contaminants from electrodes in an ion trapping experimental system is presented with results. In recent years, many advances have been made in using ion traps for quantum information processing. All of the criteria defined by DiVincenzo for using ion traps for implementing a quantum computer have been individually demonstrated, and in particular surface traps provide a scalable platform for ions. In order to be used for quantum algorithms, trapped ions need to be cooled to their motional (quantum mechanical) ground state. One of the hurdles in integrating surface ion traps for a quantum computer is minimizing electric field noise, which causes the ion to heat out of its motional ground state and which increases with smaller ion-to-electrode distances realized with surface traps. Surface contamination of trap electrodes is speculated to be the primary source of electric field noise. The main goal achieved by this work was to implement an in situ surface cleaning solution for surface electrode ion traps, which would not modify the ion trap electrode surface metal. Care was taken in applying the RF power in order to localize a plasma near the trap electrodes. A method for characterizing the energy of the plasma ions arriving at the ion trap surface is presented and results for plasma ion energies are shown. Finally, a method for quantifying the effectiveness of plasma cleaning of trap electrodes, using the surface analysis technique of X-ray photoelectron spectroscopy for measuring the amount and kind of surface contaminants, is described. A significant advantage of the trap electrode surface cleaning method presented here is the minimal changes necessary for implementation on a working ion trap experimental system.

  20. Reply to 'Comment on 'Quantum time-of-flight distribution for cold trapped atoms''

    SciTech Connect

    Ali, Md. Manirul; Home, Dipankar; Pan, Alok K.; Majumdar, A. S.

    2008-02-15

    In their comment Gomes et al. [Phys. Rev. A 77, 026101 (2008)] have questioned the possibility of empirically testable differences existing between the semiclassical time of flight distribution for cold trapped atoms and a quantum distribution discussed by us recently [Ali et al., Phys. Rev. A 75, 042110 (2007).]. We argue that their criticism is based on a semiclassical treatment having restricted applicability for a particular trapping potential. Their claim does not preclude, in general, the possibility of differences between the semiclassical calculations and fully quantum results for the arrival time distribution of freely falling atoms.

  1. Method of cold welding using ion beam technology

    NASA Technical Reports Server (NTRS)

    Sater, B. L. (Inventor)

    1981-01-01

    A method for cold welding metal joints is described. In order to remove the contamination layer on the surface of the metal, an ion beam generator is used in a vacuum environment. A gas, such as xenon or argon, is ionized and accelerated toward the metal surface. The beam of gas effectively sputters away the surface oxides and contamination layer so that clean underlying metal is exposed in the area to be welded. The use of this method allows cold welding with minimal deformation. Both similar and dissimilar metals can be cold welded with this method.

  2. Integrated System Technologies for Modular Trapped Ion Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Crain, Stephen G.

    Although trapped ion technology is well-suited for quantum information science, scalability of the system remains one of the main challenges. One of the challenges associated with scaling the ion trap quantum computer is the ability to individually manipulate the increasing number of qubits. Using micro-mirrors fabricated with micro-electromechanical systems (MEMS) technology, laser beams are focused on individual ions in a linear chain and steer the focal point in two dimensions. Multiple single qubit gates are demonstrated on trapped 171Yb+ qubits and the gate performance is characterized using quantum state tomography. The system features negligible crosstalk to neighboring ions (< 3e-4), and switching speeds comparable to typical single qubit gate times (< 2 mus). In a separate experiment, photons scattered from the 171Yb+ ion are coupled into an optical fiber with 63% efficiency using a high numerical aperture lens (0.6 NA). The coupled photons are directed to superconducting nanowire single photon detectors (SNSPD), which provide a higher detector efficiency (69%) compared to traditional photomultiplier tubes (35%). The total system photon collection efficiency is increased from 2.2% to 3.4%, which allows for fast state detection of the qubit. For a detection beam intensity of 11 mW/cm 2, the average detection time is 23.7 mus with 99.885(7)% detection fidelity. The technologies demonstrated in this thesis can be integrated to form a single quantum register with all of the necessary resources to perform local gates as well as high fidelity readout and provide a photon link to other systems.

  3. Demonstration of Long Vacuum Integrity Lifetime of a Trapped-Ion Clock Package

    NASA Astrophysics Data System (ADS)

    Bandi, T.; Prestage, J.; Chung, S.; Le, T.; Yu, N.

    2016-02-01

    A compact Hg ion trap package that has been vacuum-sealed since 2005 has been demonstrated to be successfully operational. This work shows the reliability of such units in view of next-generation ground and spaceborne trapped-ion clocks. The excellent vacuum property of the trap package allowed us to study charge transfer relaxation effects between neutral Hg and trapped Hg ions.

  4. Sensitive measurement of radiation trapping in cold-atom clouds by intensity correlation detection.

    PubMed

    Stites, Ronald; Beeler, Matthew; Feeney, Laura; Kim, Soo; Bali, Samir

    2004-12-01

    We present experimental evidence that the intensity correlations of light scattered from a cold-atom cloud are sensitive to the presence of small amounts of radiation trapping in an atomic sample of density 6 x 10(8)/cm3, with an optical depth (for a resonant light beam) of 0.4. This density and optical depth are approximately an order of magnitude less than the density and on-resonance optical depth at which effects of multiple scattering in cold-atom clouds have been previously observed [Phys. Rev. Lett. 64, 408 (1990)].

  5. Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films

    NASA Astrophysics Data System (ADS)

    Wen, Rui-Tao; Granqvist, Claes G.; Niklasson, Gunnar A.

    2015-10-01

    There is keen interest in the use of amorphous WO3 thin films as cathodic electrodes in transmittance-modulating electrochromic devices. However, these films suffer from ion-trapping-induced degradation of optical modulation and reversibility on extended Li+-ion exchange. Here, we demonstrate that ion-trapping-induced degradation, which is commonly believed to be irreversible, can be successfully eliminated by constant-current-driven de-trapping; that is, WO3 films can be rejuvenated and regain their initial highly reversible electrochromic performance. Pronounced ion trapping occurs when x exceeds ~0.65 in LixWO3 during ion insertion. We find two main kinds of Li+-ion-trapping site (intermediate and deep) in WO3, where the intermediate ones are most prevalent. Li+ ions can be completely removed from intermediate traps but are irreversibly bound in deep traps. Our results provide a general framework for developing and designing superior electrochromic materials and devices.

  6. Ultra Cold Photoelectron Beams for Ion Storage Rings

    SciTech Connect

    Orlov, D. A.; Krantz, C.; Shornikov, A.; Lestinsky, M.; Hoffmann, J.; Wolf, A.; Jaroshevich, A. S.; Kosolobov, S. N.; Terekhov, A. S.

    2009-08-04

    An ultra cold electron target with a cryogenic GaAs photocathode source, developed for the Heidelberg TSR, delivers electron currents up to a few mA with typical kinetic energies of few keV and provides unprecedented energy resolution below 1 meV for electron-ion recombination merged-beam experiments. For the new generation of low-energy electrostatic storage rings, cold electron beams from a photocathode source can bring additional benefits, improving the cooling efficiency of stored ions and making it possible to cool even heavy, slow molecules by electron beams of energies of only a few eV or even below.

  7. Upgrade of the electron beam ion trap in Shanghai

    SciTech Connect

    Lu, D.; Yang, Y.; Xiao, J.; Shen, Y.; Fu, Y.; Wei, B.; Yao, K.; Hutton, R.; Zou, Y.

    2014-09-15

    Over the last few years the Shanghai electron beam ion trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Applied Physics, first produced an electron beam in 2005. It could be tuned with electron energies between 1 and 130 keV and beam current up to 160 mA. After several years of operation, it was found that several modifications for improvements were necessary to reach the goals of better electron optics, higher photon detection, and ion injection efficiencies, and more economical running costs. The upgraded Shanghai-EBIT is made almost entirely from Ti instead of stainless steel and achieves a vacuum of less than 10{sup −10} Torr, which helps to minimize the loss of highly changed ions through charge exchange. Meanwhile, a more compact structure and efficient cryogenic system, and excellent optical alignment have been of satisfactory. The magnetic field in the central trap region can reach up till 4.8 T with a uniformity of 2.77 × 10{sup −4}. So far the upgraded Shanghai-EBIT has been operated up to an electron energy of 151 keV and a beam current of up to 218 mA, although promotion to even higher energy is still in progress. Radiation from ions as highly charged as Xe{sup 53+,} {sup 54+} has been produced and the characterization of current density is estimated from the measured electron beam width.

  8. Monitoring Trace Contaminants in Air Via Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Karr, Dane; Pearson, Richard; Valero, Gustavo; Wong, Carla

    1995-01-01

    Recent passage of the Clean Air Act with its stricter regulation of toxic gas emissions, and the ever-growing number of applications which require faster turnaround times between sampling and analysis are two major factors which are helping to drive the development of new instrument technologies for in-situ, on-line, real-time monitoring. The ion trap, with its small size, excellent sensitivity, and tandem mass spectrometry capability is a rapidly evolving technology which is well-suited for these applications. In this paper, we describe the use of a commercial ion trap instrument for monitoring trace levels of chlorofluorocarbons (CFCs) and volatile organic compounds (VOCs) in air. A number of sample introduction devices including a direct transfer line interface, short column GC, and a cryotrapping interface are employed to achieve increasing levels of sensitivity. MS, MS/MS, and MS/MS/MS methods are compared to illustrate trade-offs between sensitivity and selectivity. Filtered Noise Field (FNF) technology is found to be an excellent means for achieving lower detection limits through selective storage of the ion(s) of interest during ionization. Figures of merit including typical sample sizes, detection limits, and response times are provided. The results indicate the potential of these techniques for atmospheric assessments, the High Speed Research Program, and advanced life support monitoring applications for NASA.

  9. Laser desorption lamp ionization source for ion trap mass spectrometry.

    PubMed

    Wu, Qinghao; Zare, Richard N

    2015-01-01

    A two-step laser desorption lamp ionization source coupled to an ion trap mass spectrometer (LDLI-ITMS) has been constructed and characterized. The pulsed infrared (IR) output of an Nd:YAG laser (1064 nm) is directed to a target inside a chamber evacuated to ~15 Pa causing desorption of molecules from the target's surface. The desorbed molecules are ionized by a vacuum ultraviolet (VUV) lamp (filled with xenon, major wavelength at 148 nm). The resulting ions are stored and detected in a three-dimensional quadrupole ion trap modified from a Finnigan Mat LCQ mass spectrometer operated at a pressure of ≥ 0.004 Pa. The limit of detection for desorbed coronene molecules is 1.5 pmol, which is about two orders of magnitude more sensitive than laser desorption laser ionization mass spectrometry using a fluorine excimer laser (157 nm) as the ionization source. The mass spectrum of four standard aromatic compounds (pyrene, coronene, rubrene and 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (OPC)) shows that parent ions dominate. By increasing the infrared laser power, this instrument is capable of detecting inorganic compounds. PMID:25601688

  10. Upgrade of the electron beam ion trap in Shanghai.

    PubMed

    Lu, D; Yang, Y; Xiao, J; Shen, Y; Fu, Y; Wei, B; Yao, K; Hutton, R; Zou, Y

    2014-09-01

    Over the last few years the Shanghai electron beam ion trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Applied Physics, first produced an electron beam in 2005. It could be tuned with electron energies between 1 and 130 keV and beam current up to 160 mA. After several years of operation, it was found that several modifications for improvements were necessary to reach the goals of better electron optics, higher photon detection, and ion injection efficiencies, and more economical running costs. The upgraded Shanghai-EBIT is made almost entirely from Ti instead of stainless steel and achieves a vacuum of less than 10(-10) Torr, which helps to minimize the loss of highly changed ions through charge exchange. Meanwhile, a more compact structure and efficient cryogenic system, and excellent optical alignment have been of satisfactory. The magnetic field in the central trap region can reach up till 4.8 T with a uniformity of 2.77 × 10(-4). So far the upgraded Shanghai-EBIT has been operated up to an electron energy of 151 keV and a beam current of up to 218 mA, although promotion to even higher energy is still in progress. Radiation from ions as highly charged as Xe(53+, 54+) has been produced and the characterization of current density is estimated from the measured electron beam width.

  11. Projection of diffraction patterns for use in cold-neutral-atom trapping

    SciTech Connect

    Gillen-Christandl, Katharina; Gillen, Glen D.

    2010-12-15

    Scalar diffraction theory is combined with beam-propagation techniques to investigate the projection of near-field diffraction patterns to spatial locations away from the aperture for use in optically trapping cold neutral alkali-metal atoms. Calculations show that intensity distributions with localized bright and dark spots usually found within a millimeter of the diffracting aperture can be projected to a region free from optical components such as a cloud of cold atoms within a vacuum chamber. Calculations also predict that the critical properties of the optical dipole atom traps are not only maintained for the projected intensity patterns but also can be manipulated and improved by adjustment of the optical components outside the vacuum chamber.

  12. A mass- and velocity-broadband ion deflector for off-axis ion injection into a cyclotron resonance ion trap

    NASA Astrophysics Data System (ADS)

    Guan, Shenheng; Marshall, Alan G.

    1996-02-01

    Off-axis ion injection into an FT-ICR ion trap is desirable for capturing ions from a continuously generated beam (e.g., electrospray). A conventional E×B (Wien) filter focuses ions of a single velocity (independent of mass). Here we show that by segmenting opposed flat electrodes into small sections, the electric field may be tailored to produce well-focused ion trajectories over a wide range of ion velocity and mass-to-charge ratio, m/z. In the limit of infinitely extended deflector electrodes, small m/z, and/or high B, ion trajectories vary as powers or roots of distance.

  13. Investigation of ion capture in an electron beam ion trap charge-breeder for rare isotopes

    NASA Astrophysics Data System (ADS)

    Kittimanapun, Kritsada

    Charge breeding of rare isotope ions has become an important ingredient for providing reaccelerated rare isotope beams for science. At the National Superconducting Cyclotron Laboratory (NSCL), a reaccelerator, ReA, has been built that employs an advanced Electron Beam Ion Trap (EBIT) as a charge breeder. ReA will provide rare-isotope beams with energies of a few hundred keV/u up to tens of MeV/u to enable the study of properties of rare isotopes via low energy Coulomb excitation and transfer reactions, and to investigate nuclear reactions important for nuclear astrophysics. ReA consists of an EBIT charge breeder, a charge-over-mass selector, a room temperature radio-frequency quadrupole accelerator, and a superconducting radio-frequency linear accelerator. The EBIT charge breeder features a high-current electron gun, a long trap structure, and a hybrid superconducting magnet to reach both high acceptance for injected low-charge ions as well as high-electron beam current densities for fast charge breeding. In this work, continuous ion injection and capture in the EBIT have been investigated with a dedicated Monte-Carlo simulation code and in experimental studies. The Monte-Carlo code NEBIT considers the electron-impact ionization cross sections, space charge due to the electron beam current, ion dynamics, electric field from electrodes, and magnetic field from the superconducting magnet. Experiments were performed to study the capture efficiency as a function of injected ion beam current, electron beam current, trap size, and trap potential depth. The charge state evolution of trapped ions was studied, providing information about the effective current density of the electron beam inside the EBIT. An attempt was made to measure the effective space-charge potential of the electron beam by studying the dynamics of a beam injected and reflected inside the trap.

  14. Quantum Simulation of the Klein Paradox with Trapped Ions

    SciTech Connect

    Gerritsma, R.; Lanyon, B. P.; Kirchmair, G.; Zaehringer, F.; Hempel, C.; Blatt, R.; Roos, C. F.; Casanova, J.; Garcia-Ripoll, J. J.; Solano, E.

    2011-02-11

    We report on quantum simulations of relativistic scattering dynamics using trapped ions. The simulated state of a scattering particle is encoded in both the electronic and vibrational state of an ion, representing the discrete and continuous components of relativistic wave functions. Multiple laser fields and an auxiliary ion simulate the dynamics generated by the Dirac equation in the presence of a scattering potential. Measurement and reconstruction of the particle wave packet enables a frame-by-frame visualization of the scattering processes. By precisely engineering a range of external potentials we are able to simulate text book relativistic scattering experiments and study Klein tunneling in an analogue quantum simulator. We describe extensions to solve problems that are beyond current classical computing capabilities.

  15. On the measurement the neutron lifetime using ultra-cold neutrons in a vacuum quadrupole trap

    SciTech Connect

    Bowman, J. D.; Penttila, S. I.

    2004-01-01

    We present a conceptual design for an experiment to measure the neutron lifetime ({approx}882 s) with an accuracy of 10{sup -4}. The lifetime will be measured by observing the decay rate of a sample of UCNs confined in vacuum in a magnetic trap. The UCN collaboration at LANL has developed a prototype ultra-cold neutron UCN source that is expected to produce a bottled UCN density of more than 100 UCN/cm{sup 3}. The availability of such an intense source makes it possible to approach the measurement of the neutron lifetime in a new way. We argue below that it is possible to measure the neutron lifetime to 10{sup -4} in a vacuum magnetic trap. The measurement involves no new technology beyond the expected UCN density. If even higher densities are available, the experiment can be made better and/or less expensive. We present the design and methodology for the measurement. The slow loss of neutrons that have stable orbits, but are not energetically trapped would produce a systematic error in the measurement. We discuss a new approach, chaotic cleaning, to the elimination of quasi-neutrons from the trap by breaking the rotational symmetry of the quadrupole trap. The neutron orbits take on a chaotic character and mode mixing causes the neutrons on the quasi-bound orbits to leave the trap.

  16. The formation of Charon's red poles from seasonally cold-trapped volatiles

    NASA Astrophysics Data System (ADS)

    Grundy, W. M.; Cruikshank, D. P.; Gladstone, G. R.; Howett, C. J. A.; Lauer, T. R.; Spencer, J. R.; Summers, M. E.; Buie, M. W.; Earle, A. M.; Ennico, K.; Parker, J. Wm.; Porter, S. B.; Singer, K. N.; Stern, S. A.; Verbiscer, A. J.; Beyer, R. A.; Binzel, R. P.; Buratti, B. J.; Cook, J. C.; Dalle Ore, C. M.; Olin, C. B.; Parker, A. H.; Protopapa, S.; Quirico, E.; Retherford, K. D.; Robbins, S. J.; Schmitt, B.; Stansberry, J. A.; Umurhan, O. M.; Weaver, H. A.; Young, L. A.; Zangari, A. M.; Bray, V. J.; Cheng, A. F.; McKinnon, W. B.; McNutt, R. L.; Morre, J. M.; Nimmo, F.; Reuter, D. C.; Schenk, P. M.; New Horizons Science Team; Stern, S. A.; Bagenal, F.; Ennico, K.; Gladstone, G. R.; Grundy, W. M.; McKinnon, W. B.; Moore, J. M.; Olkin, C. B.; Spencer, J. R.; Weaver, H. A.; Young, L. A.; Andert, T.; Barnouin, O.; Beyer, R. A.; Binzel, R. P.; Bird, M.; Bray, V. J.; Brozovic, M.; Buie, M. W.; Buratti, B. J.; Cheng, A. F.; Cook, J. C.; Cruikshank, D. P.; Dalle Ore, C. M.; Earler, A. M.; Elliott, H. A.; Greathouse, T. K.; Hahn, M.; Hamilton, D. P.; Hill, M. E.; Hinson, D. P.; Hofgartner, J.; Horányi, M.; Howard, A. D.; Howett, C. J. A.; Jennings, D. E.; Kammer, J. A.; Kollmann, P.; Lauer, T. R.; Lavvas, P.; Linscott, I. R. Lisse, C. M.; Lunsford, A. W.; McComas, D. J.; McNutt, R. L., Jr.; Mutchler, M.; Nimmo, F.; Nunez, J. I.; Paetzold, M.; Parker, A. H.; Parker, J. Wm.; Philippe, S.; Piquette, M.; Porter, S. B.; Protopapa, S.; Quirico, E.; Reitsema, H. J.; Reuter, D. C.; Robbins, S. J.; Roberts, J. H.; Runyon, K.; Schenk, P. M.; Schindhelm, E.; Schmitt, B.; Showalter, M. R.; Singer, K. N.; Stansberry, J. A.; Steffl, A. J.; Strobel, D. F.; Stryk, T.; Summers, M. E.; Szalay, J. R.; Throop, H. B.; Tsang, C. C. C.; Tyler, G. L.; Umurhan, O. M.; Verbiscer, A. J.; Versteeg, M. H.; Weigle, G. E., II; White, O. L.; Woods, W. W.; Young, E. F.; Zangari, A. M.

    2016-11-01

    A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charon's high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.

  17. Io's atmosphere - Pressure control by regolith cold trapping and surface venting

    NASA Astrophysics Data System (ADS)

    Matson, D. L.; Nash, D. B.

    1983-06-01

    A new model for the basal pressure of Io's atmosphere is developed. This model takes into account the previously ignored fact that much of Io's surface has very high porosity, typically about 90 pct. Such porosity allows efficient subsurface cold trapping of atmospheric gases which tends to keep ambient surface pressures very low. SO2 is the only gas identified on Io, and the basal pressures for atmospheric models are usually pegged to local surface temperature via the SO2 vapor pressure equilibrium curve. Near Io's subsolar point the pressure in equilibrium with a surface SO2 frost deposit is about 1/10,000,000th bar. Porous surface models of the type developed invoke equilibrium with the colder, subsurface permafrost (at about 3-cm depth) and yield pressures of about 1/10 to the 12th bar. The subsurface cold trapping model explains many but not all observations relevant to Io's atmosphere. The new subsurface cold trapping model and the earlier surface frost equilibrium model, when taken together, provide lower and upper limits, respectively, on the basal SO2 pressure of Io's atmosphere.

  18. Accessing the quantum Hall regime in cold atom traps using circularly polarized light

    NASA Astrophysics Data System (ADS)

    Wooten, Rachel; Yan, Bin; Greene, Chris H.

    2016-05-01

    There has been considerable interest in designing cold atom experiments to explore the quantum Hall effect with the extreme control allowed in such trapped atom systems. Many theoretical proposals and experimental attempts have been made in the effort to construct a cold atom fractional quantum Hall experiment, but so far, the fractional quantum Hall regime has proven difficult to achieve in experimental setups. One method for reaching the quantum Hall effect consists of rapidly rotating a cold atom system in a harmonic trap to near the centrifugal limit, where the system's Hamiltonian matches the two-dimensional magnetic field Hamiltonian. This condition could be reached in a few-body system through a scheme which increases the angular momentum of the particles in the trap through precision photon excitations. According to the hyperspherical framework from few-body theory, when particle interactions break the harmonic energy spectrum degeneracy, it becomes possible for circularly polarized light to excite the system selectively into the high angular momentum states required for the quantum Hall effect. We will discuss possible experimental systems where this technique could be applicable and challenges that these systems may face.

  19. Io's atmosphere - Pressure control by regolith cold trapping and surface venting

    NASA Technical Reports Server (NTRS)

    Matson, D. L.; Nash, D. B.

    1983-01-01

    A new model for the basal pressure of Io's atmosphere is developed. This model takes into account the previously ignored fact that much of Io's surface has very high porosity, typically about 90 pct. Such porosity allows efficient subsurface cold trapping of atmospheric gases which tends to keep ambient surface pressures very low. SO2 is the only gas identified on Io, and the basal pressures for atmospheric models are usually pegged to local surface temperature via the SO2 vapor pressure equilibrium curve. Near Io's subsolar point the pressure in equilibrium with a surface SO2 frost deposit is about 1/10,000,000th bar. Porous surface models of the type developed invoke equilibrium with the colder, subsurface permafrost (at about 3-cm depth) and yield pressures of about 1/10 to the 12th bar. The subsurface cold trapping model explains many but not all observations relevant to Io's atmosphere. The new subsurface cold trapping model and the earlier surface frost equilibrium model, when taken together, provide lower and upper limits, respectively, on the basal SO2 pressure of Io's atmosphere.

  20. Soliton Reflection in a Magnetized Cold Plasma having Dust Grains and Trapped Electrons

    NASA Astrophysics Data System (ADS)

    Malik, Hitendra K.; Singh, Omveer; Dahiya, Raj P.

    2012-10-01

    A solitary wave is said to be a soliton if it retains its shape after collision with another solitary wave. The solitons get reflected from a boundary or the density gradient present in the plasma. In the present work, the reflection of a soliton is studied in a magnetized cold plasma having dust grains and trapped electrons. Considering the density inhomogeneity in the plasma, we derive relevant modified Korteweg-deVries (mKdV) equations for the right and left going solitary waves and then after coupling these equations at the point of reflection we solve the coupled equation for obtaining the expression for the reflection coefficient based on which the soliton reflection is examined under the effect of magnetic field, dust grain density, and the temperature of trapped electrons. Specifically the role of trapped electrons and dust grains is uncovered for the excitation of solitary waves and their reflection.

  1. Atmospheric H2O2 measurement: comparison of cold trap method with impinger bubbling method.

    PubMed

    Sakugawa, H; Kaplan, I R

    1987-01-01

    Collection of atmospheric H2O2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5 l min-1 for approximately 2 h. Collection efficiency was > 99% and negligible interferences by O3, SO2 or organic matter with the collected H2O2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir. Sci. Technol. 12, 1072-1080). The measured total peroxide (H2O2 + organic peroxide) values in a series of aim samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H2O2 and organic peroxide in the impinger solution by a reaction of atmospheric O3 with olefinic and aromatic compounds. If these O3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H2O2 in clouds and rainwater.

  2. Atmospheric H2O2 measurement: comparison of cold trap method with impinger bubbling method

    NASA Technical Reports Server (NTRS)

    Sakugawa, H.; Kaplan, I. R.

    1987-01-01

    Collection of atmospheric H2O2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5 l min-1 for approximately 2 h. Collection efficiency was > 99% and negligible interferences by O3, SO2 or organic matter with the collected H2O2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir. Sci. Technol. 12, 1072-1080). The measured total peroxide (H2O2 + organic peroxide) values in a series of aim samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H2O2 and organic peroxide in the impinger solution by a reaction of atmospheric O3 with olefinic and aromatic compounds. If these O3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H2O2 in clouds and rainwater.

  3. Atmospheric H2O2 measurement: comparison of cold trap method with impinger bubbling method.

    PubMed

    Sakugawa, H; Kaplan, I R

    1987-01-01

    Collection of atmospheric H2O2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5 l min-1 for approximately 2 h. Collection efficiency was > 99% and negligible interferences by O3, SO2 or organic matter with the collected H2O2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir. Sci. Technol. 12, 1072-1080). The measured total peroxide (H2O2 + organic peroxide) values in a series of aim samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H2O2 and organic peroxide in the impinger solution by a reaction of atmospheric O3 with olefinic and aromatic compounds. If these O3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H2O2 in clouds and rainwater. PMID:11542111

  4. Atmospheric H 2O 2 measurement: Comparison of cold trap method with impinger bubbling method

    NASA Astrophysics Data System (ADS)

    Sakugawa, Hiroshi; Kaplan, Isaac R.

    Collection of atmospheric H 2O 2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5ℓ -1 for ~ 2 h. Collection efficiency was > 99% and negligible interferences by O 3, SO 2 or organic matter with the collected H 2O 2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir, Sci. Technol.12, 1072-1080). The measured total peroxide (H 2O 2 + organic peroxide) values in a series of air samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H 2O 2 and organic peroxide in the impinger solution by a reaction of atmospheric O 3 with olefinic and aromatic compounds. If these O 3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H 2O 2 in clouds and rainwater.

  5. Micromotion based single-qubit addressing with trapped-ions

    NASA Astrophysics Data System (ADS)

    Akerman, Nitzan; Navon, Nir; Kotler, Shlomi; Glickman, Yinnon; Almog, Ido; Ozeri, Roee

    2013-05-01

    Individual-particle addressing is a necessary capability in many quantum information experiments. For example, characterization of multi-qubit operations with quantum process tomography (QPT). We propose and demonstrate a scheme that exploits the inhomogeneous excess micromotion in ion trap to address single-qubits in a chain of several ion-qubits, separated by only few microns. The scheme uses a laser field which is resonant with the micromotion sideband of a narrow optical quadrupole transition and acts as a dressing field with a spatially-dependent coupling along the chain. As a consequence, the level spacing of each ion, in the dressed state picture, becomes position dependent and individual ions can be spectrally separated. We have demonstrated Individual Rabi flops with 85% fidelity in a three-ion chain. For the case of only two ions, the coupling can be tailored to vanish on one of the two. This allows preparing any two-qubit product state as well as completing state tomography without direct spatially-selective imaging. We demonstrate full QPT for two-qubit Sørensen-Mølmer entangling interaction (Bell-state preparation fidelity of 98%) which has not been process-analyzed yet. Our tomography resulted process fidelity of 92%. N. Navon et al. arXiv:1210.7336 (1012).

  6. Infrared spectra of small molecular ions trapped in solid neon

    SciTech Connect

    Jacox, Marilyn E.

    2015-01-22

    The infrared spectrum of a molecular ion provides a unique signature for that species, gives information on its structure, and is amenable to remote sensing. It also serves as a comparison standard for refining ab initio calculations. Experiments in this laboratory trap molecular ions in dilute solid solution in neon at 4.2 K in sufficient concentration for observation of their infrared spectra between 450 and 4000 cm{sup !1}. Discharge-excited neon atoms produce cations by photoionization and/or Penning ionization of the parent molecule. The resulting electrons are captured by other molecules, yielding anions which provide for overall charge neutrality of the deposit. Recent observations of ions produced from C{sub 2}H{sub 4} and BF{sub 3} will be discussed. Because of their relatively large possibility of having low-lying excited electronic states, small, symmetric molecular cations are especially vulnerable to breakdown of the Born-Oppenheimer approximation. Some phenomena which can result from this breakdown will be discussed. Ion-molecule reaction rates are sufficiently high that in some systems absorptions of dimer cations and anions are also observed. When H{sub 2} is introduced into the system, the initially-formed ion may react with it. Among the species resulting from such ion-molecule reactions that have recently been studied are O{sub 4}{sup +}, NH{sub 4}{sup +}, HOCO{sup +}, and HCO{sub 2}{sup !}.

  7. Design of blade-shaped-electrode linear ion traps with reduced anharmonic contributions

    SciTech Connect

    Deng, K.; Che, H.; Ge, Y. P.; Xu, Z. T.; Yuan, W. H.; Zhang, J.; Lu, Z. H.; Lan, Y.

    2015-09-21

    RF quadrupole linear Paul traps are versatile tools in quantum physics experiments. Linear Paul traps with blade-shaped electrodes have the advantages of larger solid angles for fluorescence collection. But with these kinds of traps, the existence of higher-order anharmonic terms of the trap potentials can cause large heating rate for the trapped ions. In this paper, we theoretically investigate the dependence of higher-order terms of trap potentials on the geometry of blade-shaped traps, and offer an optimized design. A modified blade electrodes trap is proposed to further reduce higher-order anharmonic terms while still retaining large fluorescence collection angle.

  8. Cold Trap Dismantling and Sodium Removal at a Fast Breeder Reactor - 12327

    SciTech Connect

    Graf, A.; Petrick, H.; Stutz, U.; Hosking, P.

    2012-07-01

    The first German prototype Fast Breeder Nuclear Reactor (KNK) is currently being dismantled after being the only operating Fast Breeder-type reactor in Germany. As this reactor type used sodium as a coolant in its primary and secondary circuit, seven cold traps containing various amounts of partially activated sodium needed to be disposed of as part of the dismantling. The resulting combined difficulties of radioactive contamination and high chemical reactivity were handled by treating the cold traps differently depending on their size and the amount of sodium contained inside. Six small cold traps were processed onsite by cutting them up into small parts using a band saw under a protective atmosphere. The sodium was then converted to sodium hydroxide by using water. The remaining large cold trap could not be handled in the same way due to its dimensions (2.9 m x 1.1 m) and the declared amount of sodium inside (1,700 kg). It was therefore manually dismantled inside a large box filled with a protective atmosphere, while the resulting pieces were packaged for later burning in a special facility. The experiences gained by KNK during this process may be advantageous for future dismantling projects in similar sodium-cooled reactors worldwide. The dismantling of a prototype fast breeder reactor provides the challenge not only to dismantle radioactive materials but also to handle sodium-contaminated or sodium-containing components. The treatment of sodium requires additional equipment and installations to ensure a safe handling. Since it is not permitted to bring sodium into a repository, all sodium has to be neutralized either through a controlled reaction with water or by incinerating. The resulting components can be disposed of as normal radioactive waste with no further conditions. The handling of sodium needs skilled and experienced workers to minimize the inherent risks. And the example of the disposal of the large KNK cold trap shows the interaction with others and

  9. Augmenting Ion Trap Mass Spectrometers Using a Frequency Modulated Drift Tube Ion Mobility Spectrometer.

    PubMed

    Morrison, Kelsey A; Siems, William F; Clowers, Brian H

    2016-03-15

    Historically, high pressure ion mobility drift tubes have suffered from low ion duty cycles and this problem is magnified when such instrumentation is coupled with ion trap mass spectrometers. To significantly alleviate these issues, we outline the result from coupling an atmospheric pressure, dual-gate drift tube ion mobility spectrometer (IMS) to a linear ion trap mass spectrometer (LIT-MS) via modulation of the ion beam with a linear frequency chirp. The time-domain ion current, once Fourier transformed, reveals a standard ion mobility drift spectrum that corresponds to the standard mode of mobility analysis. By multiplexing the ion beam, it is possible to successfully obtain drift time spectra for an assortment of simple peptide and protein mixtures using an LIT-MS while showing improved signal intensity versus the more common signal averaging technique. Explored here are the effects of maximum injection time, solution concentration, total experiment time, and frequency swept on signal-to-noise ratios (SNRs) and resolving power. Increased inject time, concentration, and experiment time all generally led to an improvement in SNR, while a greater frequency swept increases the resolving power at the expense of SNR. Overall, chirp multiplexing of a dual-gate IMS system coupled to an LIT-MS improves ion transmission, lowers analyte detection limits, and improves spectral quality. PMID:26854901

  10. Anti-hydrogen production with positron beam ion trap

    SciTech Connect

    Itahashi, Takahisa

    2008-08-08

    In low-energy antiproton physics, it is advantageous to be able to manipulate anti-particles as freely as normal particles. A robust production and storage system for high-quality positrons and antiprotons would be a substantial advance for the development of anti-matter science. The idea of electron beam ion trap could be applied for storage of anti-particle when the electron beam could be replaced by the positron beam. The bright positron beam would be brought about using synchrotron radiation source with a superconducting wiggler. The new scheme for production of anti-particles is proposed by using new accelerator technologies.

  11. Cotrapping different species in ion traps using multiple radio frequencies

    NASA Astrophysics Data System (ADS)

    Trypogeorgos, Dimitris; Foot, Christopher J.

    2016-08-01

    We consider the stability of systems subjected to periodic parametric driving in the context of ions confined by oscillating electric fields. The behavior of these systems can be understood in terms of a pseudopotential approximation and resonances arising from parametric excitation. We investigate the key properties of a way of operating a linear Paul trap with two radio frequencies that simultaneously confines two species with extremely different charge-to-mass ratios. The theoretical calculations have been verified by molecular dynamics simulations and normal modes analysis.

  12. Trilinear hamiltonian with trapped ions and its applications

    NASA Astrophysics Data System (ADS)

    Ding, Shiqian; Maslennikov, Gleb; Hablutzel, Roland; Matsukevich, Dzmitry

    2016-05-01

    The model of three harmonic oscillators coupled by the trilinear Hamiltonian of the form a† bc + ab†c† can describe wide range of physical processes. We experimentally realize such interaction between three modes of motion in the system of 3 trapped Yb ions. We discuss several application of this coupling, including implementation of the quantum absorption refrigerator, simulation of the interaction between light and atoms described by a Tavis-Cummings model, simulation of the non-degenerate parametric down conversion process in the fully quantum regime and studies of a simple model of Hawking radiation.

  13. Robust quantum gates between trapped ions using shaped pulses

    NASA Astrophysics Data System (ADS)

    Zou, Ping; Zhang, Zhi-Ming

    2015-12-01

    We improve two existing entangling gate schemes between trapped ion qubits immersed in a large linear crystal. Based on the existing two-qubit gate schemes by applying segmented forces on the individually addressed qubits, we present a systematic method to optimize the shapes of the forces to suppress the dominant source of infidelity. The spin-dependent forces in the scheme can be from periodic photon kicks or from continuous optical pulses. The entangling gates are fast, robust, and have high fidelity. They can be used to implement scalable quantum computation and quantum simulation.

  14. Selective interactions in trapped ions: State reconstruction and quantum logic

    SciTech Connect

    Solano, E.

    2005-01-01

    We propose the implementation of selective interactions of atom-motion subspaces in trapped ions. These interactions yield resonant exchange of population inside a selected subspace, leaving the others in a highly dispersive regime. Selectivity allows us to generate motional Fock (and other nonclassical) states with high purity out of a wide class of initial states, and becomes an unconventional cooling mechanism when the ground state is chosen. Individual population of number states can be distinctively measured, as well as the motional Wigner function. Furthermore, a protocol for implementing quantum logic through a suitable control of selective subspaces is presented.

  15. Selective control of the symmetric Dicke subspace in trapped ions

    SciTech Connect

    Lopez, C. E.; Retamal, J. C.; Solano, E.

    2007-09-15

    We propose a method of manipulating selectively the symmetric Dicke subspace in the internal degrees of freedom of N trapped ions. We show that the direct access to ionic-motional subspaces, based on a suitable tuning of motion-dependent ac Stark shifts, induces a two-level dynamics involving previously selected ionic Dicke states. In this manner, it is possible to produce, sequentially and unitarily, ionic Dicke states with increasing excitation number. Moreover, we propose a probabilistic technique to produce directly any ionic Dicke state assuming suitable initial conditions.

  16. Cold atomic beam ion source for focused ion beam applications

    SciTech Connect

    Knuffman, B.; Steele, A. V.; McClelland, J. J.

    2013-07-28

    We report measurements and modeling of an ion source that is based on ionization of a laser-cooled atomic beam. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam systems. Our measurements of total ion current as a function of ionization conditions support an analytical model that also predicts the cross-sectional current density and spatial distribution of ions created in the source. The model predicts a peak brightness of 2 × 10{sup 7} A m{sup −2} sr{sup −1} eV{sup −1} and an energy spread less than 0.34 eV. The model is also combined with Monte-Carlo simulations of the inter-ion Coulomb forces to show that the source can be operated at several picoamperes with a brightness above 1 × 10{sup 7} A m{sup −2} sr{sup −1} eV{sup −1}. We estimate that when combined with a conventional ion focusing column, an ion source with these properties could focus a 1 pA beam into a spot smaller than 1 nm. A total current greater than 5 nA was measured in a lower-brightness configuration of the ion source, demonstrating the possibility of a high current mode of operation.

  17. A combined sextupole-Malmberg-Penning trap for cold non neutral plasmas and anti-hydrogen

    SciTech Connect

    Testera, G.; Amoretti, M.; Farinon, S.; Zavatarelli, S.; Canali, C.; Carraro, C.; Lagomarsino, V.; Doser, M.

    2006-10-18

    This work reports experimental data obtained with electrons stored in a Penning-Malmberg trap surrounded by a sextupole radial magnetic field. This trap geometry is one of the candidates for trapping antihydrogen atoms in the place where they are produced starting from cold antiprotons and positrons or positronium. The measurements show that electron plasmas with parameters matching the range used for positrons and electrons in the anti-hydrogen experiments (number of particles ranging from few 106 up to several 107 and densities of the order of 108 - 109 cm-3, radius of the order of 1-2 mm) can be transported with 100 % efficiency in a trap region that simultaneously confines completely the charged particles and the neutral anti-hydrogen in the radial plane. Inside this trap plasma storage times of the order of several tens of seconds up to some hundreds of seconds are measured. The plasma storage times are consistent with those needed for anti-hydrogen production; however the increase of the plasma temperature due to the expansion could prevent to get trappable antihydrogen.

  18. Linear ion trap for second-order Doppler shift reduction in frequency standard applications

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Janik, Gary R.; Dick, G. John; Maleki, Lute

    1990-01-01

    The authors have designed and are presently testing a novel linear ion trap that permits storage of a large number of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. This new trap should store about 20 times the number of ions as a conventional RF trap with no corresponding increase in second-order Doppler shift from the confining field. In addition, the sensitivity of this shift to trapping parameters, i.e., RF voltage, RF frequency, and trap size, is greatly reduced. The authors have succeeded in trapping mercury ions and xenon ions in the presence of helium buffer gas. Trap times as long as 2000 s have been measured.

  19. Model simulations of continuous ion injection into electron-beam ion source trap with slanted electrostatic mirror

    SciTech Connect

    Pikin, A.; Kponou, A.; Alessi, J. G.; Beebe, E. N.; Prelec, K.; Raparia, D.

    2008-02-15

    The efficiency of trapping ions in an electron-beam ion source (EBIS) is of primary importance for many applications requiring operations with externally produced ions: RIA breeders, ion sources, and traps. At the present time, the most popular method of ion injection is pulsed injection, when short bunches of ions get trapped in a longitudinal trap while traversing the trap region. Continuous trapping is a challenge for EBIS devices because mechanisms which reduce the longitudinal ion energy per charge in a trap (cooling with residual gas, energy exchange with other ions, and ionization) are not very effective, and accumulation of ions is slow. A possible approach to increase trapping efficiency is to slant the mirror at the end of the trap which is opposite to the injection end. A slanted mirror will convert longitudinal motion of ions into transverse motion, and, by reducing their longitudinal velocity, prevent these ions from escaping the trap on their way out. The trade-off for the increased trapping efficiency this way is an increase in the initial transverse energy of the accumulated ions. The slanted mirror can be realized if the ends of two adjacent electrodes, drift tubes, which act as an electrostatic mirror, are machined to produce a slanted gap, rather than an upright one. Applying different voltages to these electrodes will produce a slanted mirror. The results of two-dimensional (2D) and three-dimensional (3D) computer simulations of the ion injection into an EBIS are presented using simplified models of an EBIS with conical (2D simulations) and slanted (3D simulations) mirror electrodes.

  20. Low power RF amplifier circuit for ion trap applications

    NASA Astrophysics Data System (ADS)

    Noriega, J. R.; García-Delgado, L. A.; Gómez-Fuentes, R.; García-Juárez, A.

    2016-09-01

    A low power RF amplifier circuit for ion trap applications is presented and described. The amplifier is based on a class-D half-bridge amplifier with a voltage mirror driver. The RF amplifier is composed of an RF class-D amplifier, an envelope modulator to ramp up the RF voltage during the ion analysis stage, a detector or amplitude demodulation circuit for sensing the output signal amplitude, and a feedback amplifier that linearizes the steady state output of the amplifier. The RF frequency is set by a crystal oscillator and the series resonant circuit is tuned to the oscillator frequency. The resonant circuit components have been chosen, in this case, to operate at 1 MHz. In testings, the class-D stage operated at a maximum of 78 mW at 1.1356 MHz producing 225 V peak.

  1. Digital quantum simulation of Dirac equation with a trapped ion

    NASA Astrophysics Data System (ADS)

    Shen, Yangchao; Zhang, Xiang; Zhang, Junhua; Casanova, Jorge; Lamata, Lucas; Solano, Enrique; Yung, Man-Hong; Zhang, Jingning; Kim, Kihwan; Department Of Physical Chemistry Collaboration

    2014-05-01

    Recently there has been growing interest in simulating relativistic effects in controllable physical system. We digitally simulate the Dirac equation in 3 +1 dimensions with a single trapped ion. We map four internal levels of 171Yb+ ion to the Dirac bispinor. The time evolution of the Dirac equation is implemented by trotter expansion. In the 3 +1 dimension, we can observe a helicoidal motion of a free Dirac particle which reduces to Zitterbewegung in 1 +1 dimension. This work was supported in part by the National Basic Research Program of China Grant 2011CBA00300, 2011CBA00301, the National Natural Science Foundation of China Grant 61033001, 61061130540. KK acknowledge the support from the recruitment program of global youth experts.

  2. Sympathetic cooling of 171 Yb+ qubit ions on a scalable ion trap chip using Yb isotopes

    NASA Astrophysics Data System (ADS)

    Kwon, Yeong-Dae; Ahn, Jun Sik; Hong, Seokjun; Lee, Minjae; Cheon, Hongjin; Cho, Dongil ``Dan''; Kim, Taehyun

    2016-05-01

    To achieve ion trap based large-scale quantum computing devices, motional states of qubit ions must be regulated against heating from ion transportation or noise on the chip surface while leaving internal states of the ions intact. Sympathetic cooling is a natural solution for this problem, but trapping two different species of ions generally requires two sets of optical devices including separate lasers for each ion type, increasing the complexity and the cost of the setup. We tested Doppler-cooled 174 Yb+ ions to sympathetically cool 171 Yb+ qubit ions. Since these two isotopes have energy levels close to each other, the optical setup can be vastly simplified. We also verified that the tail of non-ideally focused cooling beam and the scattered light from the surface create excited state population in the 171 Yb+ qubit ions, as expected. This leads to occasional spontaneous emission events, which currently limits the coherence time of our qubit to a few seconds. We will also discuss our plans for optimizing the experiment, which may increase the coherence time by one or two orders of magnitude. This work was partially supported by ICT R&D program of MSIP/IITP. [10043464, Development of quantum repeater technology for the application to communication systems].

  3. Linear Ion Trap for the Mars Organic Molecule Analyzer

    NASA Astrophysics Data System (ADS)

    Brinckerhoff, William; Arevalo, Ricardo; Danell, Ryan; van Amerom, Friso; Pinnick, Veronica; Li, Xiang; Hovmand, Lars; Getty, Stephanie; Mahaffy, Paul; Goesmann, Fred; Steininger, Harald

    2014-05-01

    The 2018 ExoMars rover mission includes the Mars Organic Molecule Analyzer (MOMA) investigation. MOMA will examine the chemical composition of samples acquired from depths of up to two meters below the martian surface, where organics may be protected from radiative and oxidative degradation. When combined with the complement of instruments in the rover's Pasteur Payload, MOMA has the potential to reveal the presence of a wide range of organics preserved in a variety of mineralogical environments, and to begin to understand the structural character and potential origin of those compounds. MOMA includes a linear, or 2D, ion trap mass spectrometer (ITMS) that is designed to analyze molecular composition of (i) gas evolved from pyrolyzed powder samples and separated on a gas chromatograph and (ii) ions directly desorbed from solid samples at Mars ambient pressure using a pulsed laser and a fast-valve capillary ion inlet system. This "dual source" approach gives MOMA unprecedented breadth of detection over a wide range of molecular weights and volatilities. Analysis of nonvolatile, higher-molecular weight organics such as carboxylic acids and peptides even in the presence of significant perchlorate concentrations is enabled by the extremely short (~1 ns) pulses of the desorption laser. Use of the ion trap's tandem mass spectrometry mode permits selective focus on key species for isolation and controlled fragmentation, providing structural analysis capabilities. The flight-like engineering test unit (ETU) of the ITMS, now under construction, will be used to verify breadboard performance with high fidelity, while simultaneously supporting the development of analytical scripts and spectral libraries using synthetic and natural Mars analog samples guided by current results from MSL. ETU campaign data will strongly advise the specifics of the calibration applied to the MOMA flight model as well as the science operational procedures during the mission.

  4. Felion: a Cryogenic Ion Trap Apparatus for Spectroscopic Studies with Felix

    NASA Astrophysics Data System (ADS)

    Brunken, S.; Kluge, L.; Fanghanel, S.; Potapov, A.; Asvany, O.; Schlemmer, S.; Oomens, J.; Redlich, B.; Stoffels, A.

    2013-06-01

    The combination of ion trapping techniques with sensitive action spectroscopy schemes has been developed in recent years as a powerful tool to obtain spectra of gas-phase molecular ions from the UV to the (F)IR spectral regions. Here we report on the status of a specifically designed, dedicated cryogenic 22-pole ion trap apparatus (FELion), developed and built in Cologne, Germany, and intended to be installed permanently at the "Free-Electron Lasers for Infrared eXperiments" (FELIX) facility in Nijmegen, the Netherlands. This instrument will allow to record gas-phase IR and FIR spectra of mass-selected, internally cold molecular ions at temperatures in the range 4-300 K. By the use of diverse ionization methods, e.g. electron impact and electrospray ionization, a multitude of molecular ions can be generated and stored in the trap, including astrophysically relevant species ranging in size from the three-atomic H_3^+ up to large polycyclic aromatic hydrocarbon (PAH) ions, but also biomolecular ions like amino acids, peptides, or nucleobases. In combination with the powerful (F)IR radiation of the free electron lasers FELIX-1 and -2 (60-2500 cm^{-1}) and FLARE (6-100 cm^{-1}) at the FELIX facility, a variety of action spectroscopy schemes can be employed to study the ro-vibrational spectra of the stored ions, such as IR multiphoton dissociation, (F)IR/UV double resonance spectroscopy, or the method of laser induced reactions (LIR). In this talk we will give a detailed account of the experimental setup and present the first results obtained with the new apparatus. e.g., S. Schlemmer, E. Lescop, J. von Richthofen, D. Gerlich, and M. A. Smith, J. Chem. Phys. 117, 2068 (2002) J. Oomens, B. G. Sartakov, G. Meijer, and G. van Helden, Int. J. Mass Spectrom. 254, 1 (2006) T. R. Rizzo, J. A. Stearns, and O. V. Boyarkin, International Reviews in Physical Chemistry 28, 481 (2009) FLARE: Free-electron Laser for Advanced spectroscopy and high-Resolution Experiments

  5. Development and Evaluation of a Variable-Temperature Quadrupole Ion Trap Mass Spectrometer.

    PubMed

    Derkits, David; Wiseman, Alex; Snead, Russell F; Dows, Martina; Harge, Jasmine; Lamp, Jared A; Gronert, Scott

    2016-02-01

    A new, variable-temperature mass spectrometer system is described. By applying polyimide heating tape to the end-cap electrodes of a Bruker (Bremen, Germany) Esquire ion trap, it is possible to vary the effective temperature of the system between 40 and 100°C. The modification does not impact the operation of the ion trap and the heater can be used for extended periods without degradation of the system. The accuracy of the ion trap temperatures was assessed by examining two gas-phase equilibrium processes with known thermochemistry. In each case, the variable-temperature ion trap provided data that were in good accord with literature data, indicating the effective temperature in the ion trap environment was being successfully modulated by the changes in the set-point temperatures on the end-cap electrodes. The new design offers a convenient and effective way to convert commercial ion trap mass spectrometers into variable-temperature instruments. PMID:26483183

  6. A long-lived Zeeman trapped-ion qubit

    NASA Astrophysics Data System (ADS)

    Ruster, T.; Schmiegelow, C. T.; Kaufmann, H.; Warschburger, C.; Schmidt-Kaler, F.; Poschinger, U. G.

    2016-10-01

    We demonstrate unprecedentedly long lifetimes for electron spin superposition states of a single trapped ^{40}Ca^+ ion. For a Ramsey measurement, we achieve a 1{/}√{e} coherence time of 300(50) ms, while a spin-echo experiment yields a coherence time of 2.1(1) s. The latter corresponds to residual effective rms magnetic field fluctuations ≤ 2.7× 10^{-12} T during a measurement time of about 1500 s. The suppression of decoherence induced by fluctuating magnetic fields is achieved by combining a two-layer μ-metal shield, which reduces external magnetic noise by 20-30 dB for frequencies of 50 Hz-100 kHz, with Sm_2Co_{17} permanent magnets for generating a quantizing magnetic field of 0.37 mT. Our results extend the coherence time of the simple-to-operate trapped-ion spin qubit to ultralong coherence times which so far have been observed only for magnetic insensitive transitions in atomic qubits with hyperfine structure.

  7. Numerical observation of preferred directionality in ion ejection from stretched rectilinear ion traps

    NASA Astrophysics Data System (ADS)

    Krishnaveni, A.; Kumar Verma, Neeraj; Menon, A. G.; Mohanty, Atanu K.

    2008-08-01

    We report on numerical investigations of directionality of ion ejection in stretched rectilinear ion traps (RIT). Three 4-electrode trap geometries have been investigated. In all cases, one pair of electrodes has slits at their center and the other pair has no slits. The studied traps include the RIT-S, in which the mass analyzer electrodes are symmetrically positioned around the central axis; the RIT-X, in which the mass analyzer has a stretch in the direction of the electrodes which have slits (labeled as x-direction); and the RIT-Y, in which the mass analyzer has a stretch in the direction of the electrodes which have no slits (labeled as y-direction). Our analysis has been carried out on two-dimensional (2D) fields at the centre of an infinitely long mass analyzer. The boundary element method (BEM) has been used for field computations. The trajectory of ion motion has been generated using Runge Kutta fourth order integration. Three sets of simulations have been carried out on each of the RIT-S, the RIT-X and the RIT-Y to check for directionality of ion ejection. In the first, we numerically obtain the stability region on the potential (Udc- Vrf) axes. In the second we generate an escape velocity plot with UdcD0 for different values of Vrf. In the third, we simulate the mass selective boundary ejection experiment on a single ion. In the symmetric RIT-S, as expected, all three simulations show that there is an equal probability of ion reaching the trap boundary in either of the x- or y-directions. For the stretched traps, however, the results are dramatically different. For the RIT-X, all three simulations suggest that ion destabilization at the stability boundary occurs in the x-directionE Similarly, for the RIT-Y, ions preferentially get destabilized in the y-direction. That is, ions reaching the trap boundary overwhelmingly prefer the stretch direction.

  8. CuH-ZSM-5 as hydrocarbon trap under cold start conditions.

    PubMed

    Navlani-García, M; Puértolas, B; Lozano-Castelló, D; Cazorla-Amorós, D; Navarro, M V; García, T

    2013-06-01

    Cold start tests are carried out to evaluate the performance of copper-exchanged zeolites as hydrocarbon traps under simulated gasoline car exhaust gases, paying special attention to the role of copper in the performance of these zeolites. It is concluded that the partial substitution of the protons in the parent H-ZSM-5 zeolite is highly beneficial for hydrocarbon trapping due to the formation of selective adsorption sites with specific affinity for the different exhaust components. However, it is also observed that uncontrolled exchanging process conditions could lead to the presence of CuO nanoparticles in the zeolite surface, which seem to block the pore structure of the zeolite, decreasing the hydrocarbon trap efficiency. Among all the zeolites studied, the results point out that a CuH-ZSM-5 with a partial substitution of extra-framework protons by copper cations and without any detectable surface CuO nanoparticles is the zeolite that showed the best performance under simulated cold start conditions due to both the high stability and the hydrocarbon retaining capacity of this sample during the consecutive cycles. PMID:23634959

  9. Multi-element logic gates for trapped-ion qubits

    NASA Astrophysics Data System (ADS)

    Tan, T. R.; Gaebler, J. P.; Lin, Y.; Wan, Y.; Bowler, R.; Leibfried, D.; Wineland, D. J.

    2015-12-01

    Precision control over hybrid physical systems at the quantum level is important for the realization of many quantum-based technologies. In the field of quantum information processing (QIP) and quantum networking, various proposals discuss the possibility of hybrid architectures where specific tasks are delegated to the most suitable subsystem. For example, in quantum networks, it may be advantageous to transfer information from a subsystem that has good memory properties to another subsystem that is more efficient at transporting information between nodes in the network. For trapped ions, a hybrid system formed of different species introduces extra degrees of freedom that can be exploited to expand and refine the control of the system. Ions of different elements have previously been used in QIP experiments for sympathetic cooling, creation of entanglement through dissipation, and quantum non-demolition measurement of one species with another. Here we demonstrate an entangling quantum gate between ions of different elements which can serve as an important building block of QIP, quantum networking, precision spectroscopy, metrology, and quantum simulation. A geometric phase gate between a 9Be+ ion and a 25Mg+ ion is realized through an effective spin-spin interaction generated by state-dependent forces induced with laser beams. Combined with single-qubit gates and same-species entangling gates, this mixed-element entangling gate provides a complete set of gates over such a hybrid system for universal QIP. Using a sequence of such gates, we demonstrate a CNOT (controlled-NOT) gate and a SWAP gate. We further demonstrate the robustness of these gates against thermal excitation and show improved detection in quantum logic spectroscopy. We also observe a strong violation of a CHSH (Clauser-Horne-Shimony-Holt)-type Bell inequality on entangled states composed of different ion species.

  10. Multi-element logic gates for trapped-ion qubits.

    PubMed

    Tan, T R; Gaebler, J P; Lin, Y; Wan, Y; Bowler, R; Leibfried, D; Wineland, D J

    2015-12-17

    Precision control over hybrid physical systems at the quantum level is important for the realization of many quantum-based technologies. In the field of quantum information processing (QIP) and quantum networking, various proposals discuss the possibility of hybrid architectures where specific tasks are delegated to the most suitable subsystem. For example, in quantum networks, it may be advantageous to transfer information from a subsystem that has good memory properties to another subsystem that is more efficient at transporting information between nodes in the network. For trapped ions, a hybrid system formed of different species introduces extra degrees of freedom that can be exploited to expand and refine the control of the system. Ions of different elements have previously been used in QIP experiments for sympathetic cooling, creation of entanglement through dissipation, and quantum non-demolition measurement of one species with another. Here we demonstrate an entangling quantum gate between ions of different elements which can serve as an important building block of QIP, quantum networking, precision spectroscopy, metrology, and quantum simulation. A geometric phase gate between a (9)Be(+) ion and a (25)Mg(+) ion is realized through an effective spin-spin interaction generated by state-dependent forces induced with laser beams. Combined with single-qubit gates and same-species entangling gates, this mixed-element entangling gate provides a complete set of gates over such a hybrid system for universal QIP. Using a sequence of such gates, we demonstrate a CNOT (controlled-NOT) gate and a SWAP gate. We further demonstrate the robustness of these gates against thermal excitation and show improved detection in quantum logic spectroscopy. We also observe a strong violation of a CHSH (Clauser-Horne-Shimony-Holt)-type Bell inequality on entangled states composed of different ion species. PMID:26672553

  11. Design, microfabrication, and analysis of micrometer-sized cylindrical ion trap arrays

    NASA Astrophysics Data System (ADS)

    Cruz, D.; Chang, J. P.; Fico, M.; Guymon, A. J.; Austin, D. E.; Blain, M. G.

    2007-01-01

    A description of the design and microfabrication of arrays of micrometer-scale cylindrical ion traps is offered. Electrical characterization and initial ion trapping experiments with a massively parallel array of 5μm internal radius (r0) sized cylindrical ion traps (CITs) are also described. The ion trap, materials, and design are presented and shown to be critical in achieving minimal trapping potential while maintaining minimal power consumption. The ion traps, fabricated with metal electrodes, have inner radii of 1, 2, 5, and 10μm and range from 5to24μm in height. The electrical characteristics of packaged ion trap arrays were measured with a vector network analyzer. The testing focused on trapping toluene (C7H8), mass 91, 92, or 93amu, in the 5μm sized CITs. Ions were formed via electron impact ionization and were ejected by turning off the rf voltage applied to the ring electrode; a current signal was collected at this time. Optimum ionization and trapping conditions, such as a sufficient pseudopotential well and high ionization to ion loss rate ratio (as determined by simulation), proved to be difficult to establish due to the high device capacitance and the presence of exposed dielectric material in the trapping region. However, evidence was obtained suggesting the trapping of ions in 1%-15% of the traps in the array. These first tests on micrometer-scale CITs indicated the necessary materials and device design modifications for realizing ultrasmall and low power ion traps.

  12. Design, microfabrication, and analysis of micrometer-sized cylindrical ion trap arrays

    SciTech Connect

    Cruz, D.; Chang, J. P.; Fico, M.; Guymon, A. J.; Austin, D. E.; Blain, M. G.

    2007-01-15

    A description of the design and microfabrication of arrays of micrometer-scale cylindrical ion traps is offered. Electrical characterization and initial ion trapping experiments with a massively parallel array of 5 {mu}m internal radius (r{sub 0}) sized cylindrical ion traps (CITs) are also described. The ion trap, materials, and design are presented and shown to be critical in achieving minimal trapping potential while maintaining minimal power consumption. The ion traps, fabricated with metal electrodes, have inner radii of 1, 2, 5, and 10 {mu}m and range from 5 to 24 {mu}m in height. The electrical characteristics of packaged ion trap arrays were measured with a vector network analyzer. The testing focused on trapping toluene (C{sub 7}H{sub 8}), mass 91, 92, or 93 amu, in the 5 {mu}m sized CITs. Ions were formed via electron impact ionization and were ejected by turning off the rf voltage applied to the ring electrode; a current signal was collected at this time. Optimum ionization and trapping conditions, such as a sufficient pseudopotential well and high ionization to ion loss rate ratio (as determined by simulation), proved to be difficult to establish due to the high device capacitance and the presence of exposed dielectric material in the trapping region. However, evidence was obtained suggesting the trapping of ions in 1%-15% of the traps in the array. These first tests on micrometer-scale CITs indicated the necessary materials and device design modifications for realizing ultrasmall and low power ion traps.

  13. Electron Flood Charge Compensation Device for Ion Trap Secondary Ion Mass Spectrometry

    SciTech Connect

    Appelhans, Anthony David; Ward, Michael Blair; Olson, John Eric

    2002-11-01

    During secondary ion mass spectrometry (SIMS) analyses of organophosphorous compounds adsorbed onto soils, the measured anion signals were lower than expected and it was hypothesized that the low signals could be due to sample charging. An electron flood gun was designed, constructed and used to investigate sample charging of these and other sample types. The flood gun was integrated into one end cap of an ion trap secondary ion mass spectrometer and the design maintained the geometry of the self-stabilizing extraction optics used in this instrument. The SIMION ion optics program was used to design the flood gun, and experimental results agreed with the predicted performance. Results showed the low anion signals from the soils were not due to sample charging. Other insulating and conducting samples were tested using both a ReO4- and a Cs+ primary ion beam. The proximity of the sample and electron source to the ion trap aperture resulted in generation of background ions in the ion trap via electron impact (EI) ionization during the period the electron gun was flooding the sample region. When using the electron gun with the ReO4- primary beam, the required electron current was low enough that the EI background was negligible; however, the high electron flood current required with the Cs+ beam produced background EI ions that degraded the quality of the mass spectra. The consequences of the EI produced cations will have to be evaluated on a sample-by-sample basis when using electron flood. It was shown that the electron flood gun could be intentionally operated to produce EI spectra in this instrument. This offers the opportunity to measure, nearly simultaneously, species evaporating from a sample, via EI, and species bound to the surface, via SIMS.

  14. Integrated fiber-mirror ion trap for strong ion-cavity coupling

    NASA Astrophysics Data System (ADS)

    Brandstätter, B.; McClung, A.; Schüppert, K.; Casabone, B.; Friebe, K.; Stute, A.; Schmidt, P. O.; Deutsch, C.; Reichel, J.; Blatt, R.; Northup, T. E.

    2013-12-01

    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

  15. Integrated fiber-mirror ion trap for strong ion-cavity coupling

    SciTech Connect

    Brandstätter, B. Schüppert, K.; Casabone, B.; Friebe, K.; Stute, A.; Northup, T. E.; McClung, A.; Schmidt, P. O.; Deutsch, C.; Reichel, J.

    2013-12-15

    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

  16. Cycle Time Reduction in Trapped Mercury Ion Atomic Frequency Standards

    NASA Technical Reports Server (NTRS)

    Burt, Eric A.; Tjoelker, Robert L.; Taghavi, Shervin

    2011-01-01

    The use of the mercury ion isotope (201)Hg(+) was examined for an atomic clock. Taking advantage of the faster optical pumping time in (201)Hg(+) reduces both the state preparation and the state readout times, thereby decreasing the overall cycle time of the clock and reducing the impact of medium-term LO noise on the performance of the frequency standard. The spectral overlap between the plasma discharge lamp used for (201)Hg(+) state preparation and readout is much larger than that of the lamp used for the more conventional (199)Hg(+). There has been little study of (201)Hg(+) for clock applications (in fact, all trapped ion clock work in mercury has been with (199)Hg(+); however, recently the optical pumping time in (201)Hg(+) has been measured and found to be 0.45 second, or about three times faster than in (199)Hg(+) due largely to the better spectral overlap. This can be used to reduce the overall clock cycle time by over 2 seconds, or up to a factor of 2 improvement. The use of the (201)Hg(+) for an atomic clock is totally new. Most attempts to reduce the impact of LO noise have focused on reducing the interrogation time. In the trapped ion frequency standards built so far at JPL, the optical pumping time is already at its minimum so that no enhancement can be had by shortening it. However, by using (201)Hg(+), this is no longer the case. Furthermore, integrity monitoring, the mechanism that determines whether the clock is functioning normally, cannot happen faster than the clock cycle time. Therefore, a shorter cycle time will enable quicker detection of failure modes and recovery from them.

  17. Accelerated simulation study of space charge effects in quadrupole ion traps using GPU techniques.

    PubMed

    Xiong, Xingchuang; Xu, Wei; Fang, Xiang; Deng, Yulin; Ouyang, Zheng

    2012-10-01

    Space charge effects play important roles in the performance of various types of mass analyzers. Simulation of space charge effects is often limited by the computation capability. In this study, we evaluate the method of using graphics processing unit (GPU) to accelerate ion trajectory simulation. Simulation using GPU has been compared with multi-core central processing unit (CPU), and an acceleration of about 390 times have been obtained using a single computer for simulation of up to 10(5) ions in quadrupole ion traps. Characteristics of trapped ions can be investigated at detailed levels within a reasonable simulation time. Space charge effects on the trapping capacities of linear and 3D ion traps, ion cloud shapes, ion motion frequency shift, mass spectrum peak coalescence effects between two ion clouds of close m/z are studied with the ion trajectory simulation using GPU.

  18. 10 K Ring Electrode Trap - Tandem Mass Spectrometer for Infrared Spectroscopy of Mass Selected Ions

    SciTech Connect

    Goebbert, Daniel J.; Meijer, Gerard; Asmis, Knut R.

    2009-03-17

    A novel instrumental setup for measuring infrared photodissociation spectra of buffer gas cooled, mass-selected ions is described and tested. It combines a cryogenically cooled, linear radio frequency ion trap with a tandem mass spectrometer, optimally coupling continuous ion sources to pulsed laser experiments. The use of six independently adjustable DC potentials superimposed over the trapping radio frequency field provides control over the ion distribution within, as well as the kinetic energy distribution of the ions extracted from the ion trap. The scheme allows focusing the ions in space and time, such that they can be optimally irradiated by a pulsed, widely tunable infrared photodissociation laser. Ion intensities are monitored with a time-of-flight mass spectrometer mounted orthogonally to the ion trap axis.

  19. Two regimes in the decay behavior of ions from a linear r.f. Paul trap

    NASA Astrophysics Data System (ADS)

    Kwolek, Jonathan; Wells, James; Goodman, Douglas; Blümel, Reinhold; Smith, Winthrop

    2016-05-01

    A linear Paul trap (LPT) enables ions to be trapped for use in a variety of experiments. In many of these experiments, such as those measuring charge exchange or sympathetic cooling, the decay of ions from the trap is used to measure some quantity of interest. This decay is typically modeled as a single exponential. We have found that in cases where the trap is loaded to high numbers of ions, the ion decay is better described by a double exponential decay function. We have experimentally examined the decay of ions from an LPT loaded by photoionization from a magneto-optical trap as a function of the q stability parameter of the Paul trap. The LPT is loaded to steady-state, then the loading is stopped and the number of trapped ions as a function of time is monitored to determine the decay. We present numerical simulations and experimental results that demonstrate two distinct regions in the decay. For high steady-state values, the trap exhibits a double-exponential behavior. However, if the trap is filled to a steady-state value below a threshold, the decay recovers the typical single-exponential behavior. This behavior should be universal to any Paul trap regardless of the geometry or species trapped. NSF Grant No. PHY-1307874.

  20. Switching and phase transitions in a parametrically-excited cold atom trap.

    NASA Astrophysics Data System (ADS)

    Jhe, Wonho

    2008-03-01

    Stochastic dynamics of cold atoms in a modulated magneto-optical atom trap was investigated. The studies focused on the phenomena related to switching between the parametrically excited period-2 states. The rates of single-atom activated transitions were analyzed. When the atom density was increased, there were observed Ising-class phase transitions where the symmetric population of period-2 states was spontaneously broken [1,2]. Anomalous fluctuations in the decay of the unstable state were investigated [3]. [1] Kihwan Kim, Myoung-Sun Heo, Ki-Hwan Lee, Kiyoub Jang, Heung-Ryoul Noh, Doochul Kim, and Wonho Jhe, Phys. Rev. Lett. 97, 036104 (2006). [2] Kihwan Kim,. Heung-Ryoul Noh, and Wonho Jhe, Phys. Rev. A, 71, 033413 (2005). [3] ``Transient and fluctuation behavior of atomic population at unstable state in parametrically driven magneto-optical trap,'' Myoung-Sun Heo, Yonghee Kim, Heung-Ryoul Noh, Mark Dykman and Wonho Jhe, in preparation.

  1. Adsorption of ions onto nanosolids dispersed in liquid crystals: Towards understanding the ion trapping effect in nanocolloids

    NASA Astrophysics Data System (ADS)

    Garbovskiy, Yuriy

    2016-05-01

    The ion capturing effect in liquid crystal nanocolloids was quantified by means of the ion trapping coefficient. The dependence of the ion trapping coefficient on the concentration of nano-dopants and their ionic purity was calculated for a variety of nanosolids dispersed in liquid crystals: carbon nanotubes, graphene nano-flakes, diamond nanoparticles, anatase nanoparticles, and ferroelectric nanoparticles. The proposed method perfectly fits existing experimental data and can be useful in the design of highly efficient ion capturing nanomaterials.

  2. A Dual Pressure Linear Ion Trap Orbitrap Instrument with Very High Sequencing Speed*

    PubMed Central

    Olsen, Jesper V.; Schwartz, Jae C.; Griep-Raming, Jens; Nielsen, Michael L.; Damoc, Eugen; Denisov, Eduard; Lange, Oliver; Remes, Philip; Taylor, Dennis; Splendore, Maurizio; Wouters, Eloy R.; Senko, Michael; Makarov, Alexander; Mann, Matthias; Horning, Stevan

    2009-01-01

    Since its introduction a few years ago, the linear ion trap Orbitrap (LTQ Orbitrap) instrument has become a powerful tool in proteomics research. For high resolution mass spectrometry measurements ions are accumulated in the linear ion trap and passed on to the Orbitrap analyzer. Simultaneously with acquisition of this signal, the major peaks are isolated in turn, fragmented and recorded at high sensitivity in the linear ion trap, combining the strengths of both mass analyzer technologies. Here we describe a next generation LTQ Orbitrap system termed Velos, with significantly increased sensitivity and scan speed. This is achieved by a vacuum interface using a stacked ring radio frequency ion guide with 10-fold higher transfer efficiency in MS/MS mode and 3–5-fold in full scan spectra, by a dual pressure ion trap configuration, and by reduction of overhead times between scans. The first ion trap efficiently captures and fragments ions at relatively high pressure whereas the second ion trap realizes extremely fast scan speeds at reduced pressure. Ion injection times for MS/MS are predicted from full scans instead of performing automatic gain control scans. Together these improvements routinely enable acquisition of up to ten fragmentation spectra per second. Furthermore, an improved higher-energy collisional dissociation cell with increased ion extraction capabilities was implemented. Higher-collision energy dissociation with high mass accuracy Orbitrap readout is as sensitive as ion trap MS/MS scans in the previous generation of the instrument. PMID:19828875

  3. Light-induced effect on the density distribution in a sample of cold trapped atoms

    NASA Astrophysics Data System (ADS)

    Chaplik, A. V.; Ioriatti, L.; Bagnato, V. S.

    1992-12-01

    As it is known [1] an intense laser field can induce atom-atom interaction according to a dipole-dipole R -3 law. Such an interaction depends on the angle between light polarization and interatomic vector-position R. This angular dependence may produce an anisotropy in the spatial density distribution of the confined sample of cold atoms. We develop the main relations and apply them to the case of an atomic cloud of cold trapped neutral atoms with the density higher than or of the order of λ-3, where λ is the wavelength of light. The results presented here show the effect of such an interaction in a density regime of high experimental interest.

  4. Operation of a planar-electrode ion-trap array with adjustable RF electrodes

    NASA Astrophysics Data System (ADS)

    Kumph, M.; Holz, P.; Langer, K.; Meraner, M.; Niedermayr, M.; Brownnutt, M.; Blatt, R.

    2016-02-01

    One path to realizing systems of trapped atomic ions suitable for large-scale quantum computing and simulation is to create a two-dimensional (2D) array of ion traps. Interactions between nearest-neighbouring ions could then be turned on and off by tuning the ions’ relative positions and frequencies. We demonstrate and characterize the operation of a planar-electrode ion-trap array. By driving the trap with a network of phase-locked radio-frequency resonators which provide independently variable voltage amplitudes we vary the position and motional frequency of a Ca+ ion in two-dimensions within the trap array. Work on fabricating a miniaturised form of this 2D trap array is also described, which could ultimately provide a viable architecture for large-scale quantum simulations.

  5. Rapid, Site-Selective Loading of a Scalable Array of Trapped Ions

    NASA Astrophysics Data System (ADS)

    Bruzewicz, Colin; McConnell, Robert; Chiaverini, John; Sage, Jeremy

    2016-05-01

    Rapid trap reloading is a requirement for any scalable quantum information processor based on trapped-ion qubits. Even cryogenic systems with trap lifetimes in excess of 10 hours will require loading rates of approximately 100 s-1 to maintain arrays of millions of ions. Further, the reloading process should not introduce unacceptable levels of decoherence into other ions within the array. Here, we demonstrate rapid, site-selective, random-access loading of a 2x2 array of trapped ions that satisfies the major criteria for scalable quantum processing. This scheme uses a continuous flux of pre-cooled strontium atoms and a pair of orthogonal photo-ionization lasers to load surface-electrode point Paul traps at average rates greater than 400 s-1. Additionally, we have conducted a series of Ramsey experiments to measure the effects of loading on the coherence of nearby trapped ions.

  6. Measuring and manipulating the temperature of cold molecules trapped on a chip

    NASA Astrophysics Data System (ADS)

    Marx, S.; Adu Smith, D.; Insero, G.; Meek, S. A.; Sartakov, B. G.; Meijer, G.; Santambrogio, G.

    2015-12-01

    Following Marx et al. [Phys. Rev. Lett. 111, 243007 (2013), 10.1103/PhysRevLett.111.243007], we discuss the measurement and manipulation of the temperature of cold CO molecules in a microchip environment. In particular, we present a model to explain the observed and calculated velocity distributions. We also show that a translational temperature can be extracted directly from the measurements. Finally, we discuss the conditions needed for an effective adiabatic cooling of the molecular ensemble trapped on the microchip.

  7. Fundamentals of Trapped Ion Mobility Spectrometry Part II: Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Silveira, Joshua A.; Michelmann, Karsten; Ridgeway, Mark E.; Park, Melvin A.

    2016-04-01

    Trapped ion mobility spectrometry (TIMS) is a new high resolution (R up to ~300) separation technique that utilizes an electric field to hold ions stationary against a moving gas. Recently, an analytical model for TIMS was derived and, in part, experimentally verified. A central, but not yet fully explored, component of the model involves the fluid dynamics at work. The present study characterizes the fluid dynamics in TIMS using simulations and ion mobility experiments. Results indicate that subsonic laminar flow develops in the analyzer, with pressure-dependent gas velocities between ~120 and 170 m/s measured at the position of ion elution. One of the key philosophical questions addressed is: how can mobility be measured in a dynamic system wherein the gas is expanding and its velocity is changing? We noted previously that the analytically useful work is primarily done on ions as they traverse the electric field gradient plateau in the analyzer. In the present work, we show that the position-dependent change in gas velocity on the plateau is balanced by a change in pressure and temperature, ultimately resulting in near position-independent drag force. That the drag force, and related variables, are nearly constant allows for the use of relatively simple equations to describe TIMS behavior. Nonetheless, we derive a more comprehensive model, which accounts for the spatial dependence of the flow variables. Experimental resolving power trends were found to be in close agreement with the theoretical dependence of the drag force, thus validating another principal component of TIMS theory.

  8. High-precision force sensing using a single trapped ion.

    PubMed

    Ivanov, Peter A; Vitanov, Nikolay V; Singer, Kilian

    2016-01-01

    We introduce quantum sensing schemes for measuring very weak forces with a single trapped ion. They use the spin-motional coupling induced by the laser-ion interaction to transfer the relevant force information to the spin-degree of freedom. Therefore, the force estimation is carried out simply by observing the Ramsey-type oscillations of the ion spin states. Three quantum probes are considered, which are represented by systems obeying the Jaynes-Cummings, quantum Rabi (in 1D) and Jahn-Teller (in 2D) models. By using dynamical decoupling schemes in the Jaynes-Cummings and Jahn-Teller models, our force sensing protocols can be made robust to the spin dephasing caused by the thermal and magnetic field fluctuations. In the quantum-Rabi probe, the residual spin-phonon coupling vanishes, which makes this sensing protocol naturally robust to thermally-induced spin dephasing. We show that the proposed techniques can be used to sense the axial and transverse components of the force with a sensitivity beyond the range, i.e. in the (xennonewton, 10(-27)). The Jahn-Teller protocol, in particular, can be used to implement a two-channel vector spectrum analyzer for measuring ultra-low voltages. PMID:27306426

  9. High-precision force sensing using a single trapped ion

    NASA Astrophysics Data System (ADS)

    Ivanov, Peter A.; Vitanov, Nikolay V.; Singer, Kilian

    2016-06-01

    We introduce quantum sensing schemes for measuring very weak forces with a single trapped ion. They use the spin-motional coupling induced by the laser-ion interaction to transfer the relevant force information to the spin-degree of freedom. Therefore, the force estimation is carried out simply by observing the Ramsey-type oscillations of the ion spin states. Three quantum probes are considered, which are represented by systems obeying the Jaynes-Cummings, quantum Rabi (in 1D) and Jahn-Teller (in 2D) models. By using dynamical decoupling schemes in the Jaynes-Cummings and Jahn-Teller models, our force sensing protocols can be made robust to the spin dephasing caused by the thermal and magnetic field fluctuations. In the quantum-Rabi probe, the residual spin-phonon coupling vanishes, which makes this sensing protocol naturally robust to thermally-induced spin dephasing. We show that the proposed techniques can be used to sense the axial and transverse components of the force with a sensitivity beyond the range, i.e. in the (xennonewton, 10‑27). The Jahn-Teller protocol, in particular, can be used to implement a two-channel vector spectrum analyzer for measuring ultra-low voltages.

  10. High-precision force sensing using a single trapped ion

    PubMed Central

    Ivanov, Peter A.; Vitanov, Nikolay V.; Singer, Kilian

    2016-01-01

    We introduce quantum sensing schemes for measuring very weak forces with a single trapped ion. They use the spin-motional coupling induced by the laser-ion interaction to transfer the relevant force information to the spin-degree of freedom. Therefore, the force estimation is carried out simply by observing the Ramsey-type oscillations of the ion spin states. Three quantum probes are considered, which are represented by systems obeying the Jaynes-Cummings, quantum Rabi (in 1D) and Jahn-Teller (in 2D) models. By using dynamical decoupling schemes in the Jaynes-Cummings and Jahn-Teller models, our force sensing protocols can be made robust to the spin dephasing caused by the thermal and magnetic field fluctuations. In the quantum-Rabi probe, the residual spin-phonon coupling vanishes, which makes this sensing protocol naturally robust to thermally-induced spin dephasing. We show that the proposed techniques can be used to sense the axial and transverse components of the force with a sensitivity beyond the range, i.e. in the (xennonewton, 10−27). The Jahn-Teller protocol, in particular, can be used to implement a two-channel vector spectrum analyzer for measuring ultra-low voltages. PMID:27306426

  11. Conformation-specific spectroscopy of peptide fragment ions in a low-temperature ion trap.

    PubMed

    Wassermann, Tobias N; Boyarkin, Oleg V; Paizs, Béla; Rizzo, Thomas R

    2012-06-01

    We have applied conformer-selective infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy at low temperatures in an ion trap mass spectrometer for the spectroscopic characterization of peptide fragment ions. We investigate b- and a-type ions formed by collision-induced dissociation from protonated leucine-enkephalin. The vibrational analysis and assignment are supported by nitrogen-15 isotopic substitution of individual amino acid residues and assisted by density functional theory calculations. Under such conditions, b-type ions of different size are found to appear exclusively as linear oxazolone structures with protonation on the N-terminus, while a rearrangement reaction is confirmed for the a (4) ion in which the side chain of the C-terminal phenylalanine residue is transferred to the N-terminal side of the molecule. The vibrational spectra that we present here provide a particularly stringent test for theoretical approaches.

  12. Conformation-Specific Spectroscopy of Peptide Fragment Ions in a Low-Temperature Ion Trap

    NASA Astrophysics Data System (ADS)

    Wassermann, Tobias N.; Boyarkin, Oleg V.; Paizs, Béla; Rizzo, Thomas R.

    2012-06-01

    We have applied conformer-selective infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy at low temperatures in an ion trap mass spectrometer for the spectroscopic characterization of peptide fragment ions. We investigate b- and a-type ions formed by collision-induced dissociation from protonated leucine-enkephalin. The vibrational analysis and assignment are supported by nitrogen-15 isotopic substitution of individual amino acid residues and assisted by density functional theory calculations. Under such conditions, b-type ions of different size are found to appear exclusively as linear oxazolone structures with protonation on the N-terminus, while a rearrangement reaction is confirmed for the a 4 ion in which the side chain of the C-terminal phenylalanine residue is transferred to the N-terminal side of the molecule. The vibrational spectra that we present here provide a particularly stringent test for theoretical approaches.

  13. Quantum simulation of dynamical maps with trapped ions

    NASA Astrophysics Data System (ADS)

    Schindler, P.; Müller, M.; Nigg, D.; Barreiro, J. T.; Martinez, E. A.; Hennrich, M.; Monz, T.; Diehl, S.; Zoller, P.; Blatt, R.

    2013-06-01

    Dynamical maps describe general transformations of the state of a physical system--their iteration interpreted as generating a discrete time evolution. Prime examples include classical nonlinear systems undergoing transitions to chaos. Quantum mechanical counterparts show intriguing phenomena such as dynamical localization on the single-particle level. Here we extend the concept of dynamical maps to a many-particle context, where the time evolution involves both coherent and dissipative elements: we experimentally explore the stroboscopic dynamics of a complex many-body spin model with a universal trapped ion quantum simulator. We generate long-range phase coherence of spin by an iteration of purely dissipative quantum maps and demonstrate the characteristics of competition between combined coherent and dissipative non-equilibrium evolution--the hallmark of a previously unobserved dynamical phase transition. We assess the influence of experimental errors in the quantum simulation and tackle this problem by developing an efficient error detection and reduction toolbox based on quantum feedback.

  14. Gate Set Tomography on a trapped ion qubit

    NASA Astrophysics Data System (ADS)

    Nielsen, Erik; Blume-Kohout, Robin; Gamble, John; Rundinger, Kenneth; Mizrahi, Jonathan; Sterk, Johathan; Maunz, Peter

    2015-03-01

    We present enhancements to gate-set tomography (GST), which is a framework in which an entire set of quantum logic gates (including preparation and measurement) can be fully characterized without need for pre-calibrated operations. Our new method, ``extended Linear GST'' (eLGST) uses fast, reliable analysis of structured long gate sequences to deliver tomographic precision at the Heisenberg limit with GST's calibration-free framework. We demonstrate this precision on a trapped-ion qubit, and show significant (orders of magnitude) advantage over both standard process tomography and randomized benchmarking. This work was supported by the Laboratory Directed Research and Development (LDRD) program at Sandia National Laboratories. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  15. Fast control of trapped ion qubits using shaped optical pulses

    NASA Astrophysics Data System (ADS)

    Rangan, Chitra; Monroe, C. R.; Bucksbaum, P. H.; Bloch, A. M.

    2003-05-01

    We present a fast control scheme for producing arbitrary states of trapped ion qubits via shaped optical pulses. When the atomic wavepacket is not localized to under a wavelength (beyond the Lamb-Dicke limit), we show that, we show that the Hilbert space of the qubit-harmonic oscillator can be made finite, and the Schrödinger equation controllable. We then implement an optimal control formalism to determine the pulse shapes that can drive the system to any desired state. This process is faster than using sequential single-frequency laser fields to achieve the same final state. We discuss control schemes for producing entangled states of two qubits. We show progress towards achieving decoherence-free subspaces that could be used in error correction schemes.

  16. Limiting temperature of sympathetically cooled ions in a radio-frequency trap

    SciTech Connect

    Hasegawa, Taro; Shimizu, Tadao

    2003-01-01

    The limiting temperature achieved by sympathetic cooling in an rf trap is calculated with a theoretical model in which no fitting parameters are used. The calculated result agrees well with observation. The dependence of the temperature on trapping parameters and ion mass is also analyzed. The results can be used for designing an rf trap system.

  17. UV photodissociation of trapped ions following ion mobility separation in a Q-ToF mass spectrometer.

    PubMed

    Bellina, Bruno; Brown, Jeffery M; Ujma, Jakub; Murray, Paul; Giles, Kevin; Morris, Michael; Compagnon, Isabelle; Barran, Perdita E

    2014-12-21

    An ion mobility mass spectrometer has been modified to allow optical interrogation of ions with different mass-to-charge (m/z) ratios and/or mobilities (K). An ion gating and trapping procedure has been developed which allows us to store ions for several seconds enabling UV photodissociation (UVPD).

  18. 'Programming' Electron Beam Ion Traps To Produce Atomic Data Relevant To Plasma Physics

    SciTech Connect

    Currell, Fred; O'Rourke, Brian; Kavanagh, Anthony; Li Yueming; Nakamura, Nobuyuki; Ohtani, Shunsuke; Watanabe, Hirofumi

    2009-09-10

    After a brief review of the processes taking place in electron beam ions traps (EBITs), the means by which EBITs are used to make measurements of electron impact ionization cross-sections and dielectronic recombination resonance strengths are discussed. In particular, results from a study involving holmium ions extracted from an electron beam ion trap are used to illustrate a technique for studying dielectronic recombination in open-shell target ions.

  19. Trapping of Intact, Singly-Charged, Bovine Serum Albumin Ions Injected from the Atmosphere with a 10-cm Diameter, Frequency-Adjusted Linear Quadrupole Ion Trap

    SciTech Connect

    Koizumi, Hideya; Whitten, William B; Reilly, Pete

    2008-12-01

    High-resolution real-time particle mass measurements have not been achievable because the enormous amount of kinetic energy imparted to the particles upon expansion into vacuum competes with and overwhelms the forces applied to the charged particles within the mass spectrometer. It is possible to reduce the kinetic energy of a collimated particulate ion beam through collisions with a buffer gas while radially constraining their motion using a quadrupole guide or trap over a limited mass range. Controlling the pressure drop of the final expansion into a quadrupole trap permits a much broader mass range at the cost of sacrificing collimation. To achieve high-resolution mass analysis of massive particulate ions, an efficient trap with a large tolerance for radial divergence of the injected ions was developed that permits trapping a large range of ions for on-demand injection into an awaiting mass analyzer. The design specifications required that frequency of the trapping potential be adjustable to cover a large mass range and the trap radius be increased to increase the tolerance to divergent ion injection. The large-radius linear quadrupole ion trap was demonstrated by trapping singly-charged bovine serum albumin ions for on-demand injection into a mass analyzer. Additionally, this work demonstrates the ability to measure an electrophoretic mobility cross section (or ion mobility) of singly-charged intact proteins in the low-pressure regime. This work represents a large step toward the goal of high-resolution analysis of intact proteins, RNA, DNA, and viruses.

  20. Spin-Orbit Interactions and Quantum Spin Dynamics in Cold Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Tscherbul, Timur V.; Brumer, Paul; Buchachenko, Alexei A.

    2016-09-01

    We present accurate ab initio and quantum scattering calculations on a prototypical hybrid ion-atom system Yb+ -Rb, recently suggested as a promising candidate for the experimental study of open quantum systems, quantum information processing, and quantum simulation. We identify the second-order spin-orbit (SO) interaction as the dominant source of hyperfine relaxation in cold Yb+ -Rb collisions. Our results are in good agreement with recent experimental observations [L. Ratschbacher et al., Phys. Rev. Lett. 110, 160402 (2013)] of hyperfine relaxation rates of trapped Yb+ immersed in an ultracold Rb gas. The calculated rates are 4 times smaller than is predicted by the Langevin capture theory and display a weak T-0.3 temperature dependence, indicating significant deviations from statistical behavior. Our analysis underscores the deleterious nature of the SO interaction and implies that light ion-atom combinations such as Yb+ -Li should be used to minimize hyperfine relaxation and decoherence of trapped ions in ultracold atomic gases.

  1. Inhomogeneous BCS-BEC crossover for trapped cold atoms in optical lattices

    NASA Astrophysics Data System (ADS)

    Amaricci, A.; Privitera, A.; Capone, M.

    2014-05-01

    The BCS-BEC (Bose-Einstein condensation) crossover in a lattice is a powerful paradigm that describes how a superconductor deviates from the Bardeen-Cooper-Schrieffer physics as the attractive interaction increases. Optical lattices loaded with binary mixtures of cold atoms allow one to access this phenomenon experimentally in a clean and controlled way. We show that, however, the possibility to study this phenomenon in actual cold-atoms experiments is limited by the effect of the trapping potential. Real-space dynamical mean-field theory calculations show indeed that interactions and the confining potential conspire to pack the fermions in the center of the trap, which approaches a band insulator when the attraction becomes sizeable. Interestingly, the energy gap is spatially more homogeneous than the superfluid condensate order parameter. We show how this physics reflects in several observables, and we propose an alternative strategy to disentangle the effect of the harmonic potential and measure the intrinsic properties resulting from the interaction strength.

  2. Adiabatic coherent control in the anharmonic ion trap: Numerical analysis of vibrational anharmonicities

    SciTech Connect

    Wang Lei; Babikov, Dmitri

    2011-02-15

    Anharmonicity of the quantized motional states of ions in a Paul trap can be utilized to address the state-to-state transitions selectively and control the motional modes of trapped ions coherently and adiabatically [Zhao and Babikov, Phys. Rev. A 77, 012338 (2008)]. In this paper we study two sources of the vibrational anharmonicity in the ion traps: the intrinsic Coulomb anharmonicity due to ion-ion interactions and the external anharmonicity of the trapping potential. An accurate numerical approach is used to compute energies and wave functions of vibrational eigenstates. The magnitude of the Coulomb anharmonicity is determined and shown to be insufficient for successful control. In contrast, anharmonicity of the trapping potential allows one to control the motion of ions very efficiently using the time-varying electric fields. Optimal control theory is used to derive the control pulses. One ion in a slightly anharmonic trap can be easily controlled. In the two- and three-ion systems the symmetric stretching mode is dark and cannot be controlled at all. The other two normal modes of the three-ion system can be controlled and used, for example, to encode a two-qubit system into the motional states of ions. A trap architecture that allows the necessary amount of vibrational anharmonicity to be achieved is proposed.

  3. Extending the Dynamic Range of the Ion Trap by Differential Mobility Filtration

    NASA Astrophysics Data System (ADS)

    Hall, Adam B.; Coy, Stephen L.; Kafle, Amol; Glick, James; Nazarov, Erkinjon; Vouros, Paul

    2013-09-01

    A miniature, planar, differential ion mobility spectrometer (DMS) was interfaced to an LCQ classic ion trap to conduct selective ion filtration prior to mass analysis in order to extend the dynamic range of the trap. Space charge effects are known to limit the functional ion storage capacity of ion trap mass analyzers and this, in turn, can affect the quality of the mass spectral data generated. This problem is further exacerbated in the analysis of mixtures where the indiscriminate introduction of matrix ions results in premature trap saturation with non-targeted species, thereby reducing the number of parent ions that may be used to conduct MS/MS experiments for quantitation or other diagnostic studies. We show that conducting differential mobility-based separations prior to mass analysis allows the isolation of targeted analytes from electrosprayed mixtures preventing the indiscriminate introduction of matrix ions and premature trap saturation with analytically unrelated species. Coupling these two analytical techniques is shown to enhance the detection of a targeted drug metabolite from a biological matrix. In its capacity as a selective ion filter, the DMS can improve the analytical performance of analyzers such as quadrupole (3D or linear) and ion cyclotron resonance (FT-ICR) ion traps that depend on ion accumulation.

  4. Extending the Dynamic Range of the Ion Trap by Differential Mobility Filtration

    PubMed Central

    Hall, Adam B.; Coy, Stephen L.; Kafle, Amol; Glick, James; Nazarov, Erkinjon

    2013-01-01

    A miniature, planar, differential ion mobility spectrometer (DMS) was interfaced to an LCQ classic ion trap to conduct selective ion filtration prior to mass analysis in order to extend the dynamic range of the trap. Space charge effects are known to limit the functional ion storage capacity of ion trap mass analyzers and this, in turn, can affect the quality of the mass spectral data generated. This problem is further exacerbated in the analysis of mixtures where the indiscriminate introduction of matrix ions results in premature trap saturation with non-targeted species, thereby reducing the number of parent ions that may be used to conduct MS/MS experiments for quantitation or other diagnostic studies. We show that conducting differential mobility-based separations prior to mass analysis allows the isolation of targeted analytes from electrosprayed mixtures preventing the indiscriminate introduction of matrix ions and premature trap saturation with analytically unrelated species. Coupling these two analytical techniques is shown to enhance the detection of a targeted drug metabolite from a biological matrix. In its capacity as a selective ion filter, the DMS can improve the analytical performance of analyzers such as quadrupole (3-D or linear) and ion cyclotron resonance (FT-ICR) ion traps that depend on ion accumulation. PMID:23797861

  5. Technologies for trapped-ion quantum information systems - Progress toward scalability with hybrid systems

    NASA Astrophysics Data System (ADS)

    Eltony, Amira M.; Gangloff, Dorian; Shi, Molu; Bylinskii, Alexei; Vuletić, Vladan; Chuang, Isaac L.

    2016-03-01

    Scaling up from prototype systems to dense arrays of ions on chip, or vast networks of ions connected by photonic channels, will require developing entirely new technologies that combine miniaturized ion trapping systems with devices to capture, transmit, and detect light, while refining how ions are confined and controlled. Building a cohesive ion system from such diverse parts involves many challenges, including navigating materials incompatibilities and undesired coupling between elements. Here, we review our recent efforts to create scalable ion systems incorporating unconventional materials such as graphene and indium tin oxide, integrating devices like optical fibers and mirrors, and exploring alternative ion loading and trapping techniques.

  6. Stability Diagrams for Paul Ion Traps Driven by Two-Frequencies.

    PubMed

    Possa, Gabriela C; Roncaratti, Luiz F

    2016-07-14

    In this paper, we present and discuss stability diagrams for Paul traps driven by two ac voltages. In contrast to a typical Paul trap, here we suggest a secondary ac voltage whose frequency is twice the frequency of the primary one. The ratio between their amplitudes can be used to expand the region of stability and to access different states of motion of trapped ions. This provides a further mechanism to trap, cool, and manipulate single ions and also to improve the experimental framework where ion clouds and crystals can be prepared and controlled. Such approach opens the possibility of designing more sophisticated trapping architectures, leading to a wide variety of applications on ion trap research and mass analysis techniques.

  7. Excitation of High-Frequency Internal Kink Mode by Deeply-Trapped Energetic Ions

    NASA Astrophysics Data System (ADS)

    Li, Wen; Wang, Shaojie

    2010-08-01

    Deeply trapped energetic ions can destabilize the internal kink mode with both high and low frequencies with a potato-orbit limit in the EAST-like tokamaks. The threshold beta value of the deeply trapped energetic ions, the real frequency, and the growth rate of the internal kink mode are predicted in this paper.

  8. X-ray spectroscopy of highly-ionized atoms in an electron beam ion trap (EBIT)

    SciTech Connect

    Marrs, R.E.; Bennett, C.; Chen, M.H.; Cowan, T.; Dietrich, D.; Henderson, J.R.; Knapp, D.A.; Levine, M.A.; Schneider, M.B.; Scofield, J.H.

    1988-01-01

    An Electron Beam Ion Trap at Lawrence Livermore National Laboratory is being used to produce and trap very-highly-charged-ions (q /le/ 70+) for x-ray spectroscopy measurements. Recent measurements of dielectronic recombination, electron impact excitation and transition energies are presented. 15 refs., 12 figs., 1 tab.

  9. Cold ion demagnetization near the X-line of magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Toledo-Redondo, Sergio; André, Mats; Khotyaintsev, Yuri V.; Vaivads, Andris; Walsh, Andrew; Li, Wenya; Graham, Daniel B.; Lavraud, Benoit; Masson, Arnaud; Aunai, Nicolas; Divin, Andrey; Dargent, Jeremy; Fuselier, Stephen; Gershman, Daniel J.; Dorelli, John; Giles, Barbara; Avanov, Levon; Pollock, Craig; Saito, Yoshifumi; Moore, Thomas E.; Coffey, Victoria; Chandler, Michael O.; Lindqvist, Per-Arne; Torbert, Roy; Russell, Christopher T.

    2016-07-01

    Although the effects of magnetic reconnection in magnetospheres can be observed at planetary scales, reconnection is initiated at electron scales in a plasma. Surrounding the electron diffusion region, there is an Ion-Decoupling Region (IDR) of the size of the ion length scales (inertial length and gyroradius). Reconnection at the Earth's magnetopause often includes cold magnetospheric (few tens of eV), hot magnetospheric (10 keV), and magnetosheath (1 keV) ions, with different gyroradius length scales. We report observations of a subregion inside the IDR of the size of the cold ion population gyroradius (˜15 km) where the cold ions are demagnetized and accelerated parallel to the Hall electric field. Outside the subregion, cold ions follow the E × B motion together with electrons, while hot ions are demagnetized. We observe a sharp cold ion density gradient separating the two regions, which we identify as the cold and hot IDRs.

  10. Automated on-line preconcentration of trace aqueous mercury with gold trap focusing for cold vapor atomic absorption spectrometry.

    PubMed

    Puanngam, Mahitti; Dasgupta, Purnendu K; Unob, Fuangfa

    2012-09-15

    A fully automated system for the determination of trace mercury in water by cold vapor atomic absorption spectrometry (CVAAS) is reported. The system uses preconcentration on a novel sorbent followed by liberation of the mercury and focusing by a gold trap. Mercury ions were extracted from water samples by passage through a solid phase sorbent column containing 2-(3-(2-aminoethylthio)propylthio)ethanamine modified silica gel. The captured mercury is released by thiourea and then elemental Hg is liberated by sodium borohydride. The vapor phase Hg is recaptured on a gold-plated tungsten filament. This is liberated as a sharp pulse (half-width<2 s) by directly electrically heating the tungsten filament in a dry argon stream. The mercury is measured by CVAAS; no moisture removal is needed. The effects of chloride and selected interfering ions were studied. The sample loading flow rate and argon flow rates for solution purging and filament sweeping were optimized. An overall 50-fold improvement in the limit of detection was observed relative to direct measurement by CVAAS. With a relatively modest multi-user instrument we attained a limit of detection of 35 ng L(-1) with 12% RSD at 0.20 μg L(-1) Hg level. The method was successfully applied to accurately determine sub-μg L(-1) level Hg in standard reference water samples.

  11. Divalent ion trapping inside potassium channels of human T lymphocytes

    PubMed Central

    1989-01-01

    Using the patch-clamp whole-cell recording technique, we investigated the influence of external Ca2+, Ba2+, K+, Rb+, and internal Ca2+ on the rate of K+ channel inactivation in the human T lymphocyte-derived cell line, Jurkat E6-1. Raising external Ca2+ or Ba2+, or reducing external K+, accelerated the rate of the K+ current decay during a depolarizing voltage pulse. External Ba2+ also produced a use-dependent block of the K+ channels by entering the open channel and becoming trapped inside. Raising internal Ca2+ accelerated inactivation at lower concentrations than external Ca2+, but increasing the Ca2+ buffering with BAPTA did not affect inactivation. Raising [K+]o or adding Rb+ slowed inactivation by competing with divalent ions. External Rb+ also produced a use-dependent removal of block of K+ channels loaded with Ba2+ or Ca2+. From the removal of this block we found that under normal conditions approximately 25% of the channels were loaded with Ca2+, whereas under conditions with 10 microM internal Ca2+ the proportion of channels loaded with Ca2+ increased to approximately 50%. Removing all the divalent cations from the external and internal solution resulted in the induction of a non-selective, voltage-independent conductance. We conclude that Ca2+ ions from the outside or the inside can bind to a site at the K+ channel and thereby block the channel or accelerate inactivation. PMID:2786551

  12. Quantum Simulation with 2D Arrays of Trapped Ions

    NASA Astrophysics Data System (ADS)

    Richerme, Philip

    2016-05-01

    The computational difficulty of solving fully quantum many-body spin problems is a significant obstacle to understanding the behavior of strongly correlated quantum matter. This work proposes the design and construction of a 2D quantum spin simulator to investigate the physics of frustrated materials, highly entangled states, mechanisms potentially underpinning high-temperature superconductivity, and other topics inaccessible to current 1D systems. The effective quantum spins will be encoded within the well-isolated electronic levels of trapped ions, confined in a two-dimensional planar geometry, and made to interact using phonon-mediated optical dipole forces. The system will be scalable to 100+ quantum particles, far beyond the realm of classical intractability, while maintaining individual-ion control, long quantum coherence times, and site-resolved projective spin measurements. Once constructed, the two-dimensional quantum simulator will implement a broad range of spin models on a variety of reconfigurable lattices and characterize their behavior through measurements of spin-spin correlations and entanglement. This versatile tool will serve as an important experimental resource for exploring difficult quantum many-body problems in a regime where classical methods fail.

  13. Ion collision cross section analyses in quadrupole ion traps using the filter diagonalization method: a theoretical study.

    PubMed

    Jiang, Ting; He, Miyi; Guo, Dan; Zhai, Yanbing; Xu, Wei

    2016-04-28

    Previously, we have demonstrated the feasibility of measuring ion collision cross sections (CCSs) within a quadrupole ion trap by performing time-frequency analyses of simulated ion trajectories. In this study, an improved time-frequency analysis method, the filter diagonalization method (FDM), was applied for data analyses. Using the FDM, high resolution could be achieved in both time- and frequency-domains when calculating ion time-frequency curves. Owing to this high-resolution nature, ion-neutral collision induced ion motion frequency shifts were observed, which further cause the intermodulation of ion trajectories and thus accelerate image current attenuation. Therefore, ion trap operation parameters, such as the ion number, high-order field percentage and buffer gas pressure, were optimized for ion CCS measurements. Under optimized conditions, simulation results show that a resolving power from 30 to more than 200 could be achieved for ion CCS measurements. PMID:27066889

  14. Control of the conformations of ion Coulomb crystals in a Penning trap.

    PubMed

    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

  15. Control of the conformations of ion Coulomb crystals in a Penning trap.

    PubMed

    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.

  16. Guidelines for Designing Surface Ion Traps Using the Boundary Element Method

    PubMed Central

    Hong, Seokjun; Lee, Minjae; Cheon, Hongjin; Kim, Taehyun; Cho, Dong-il “Dan”

    2016-01-01

    Ion traps can provide both physical implementation of quantum information processing and direct observation of quantum systems. Recently, surface ion traps have been developed using microfabrication technologies and are considered to be a promising platform for scalable quantum devices. This paper presents detailed guidelines for designing the electrodes of surface ion traps. First, we define and explain the key specifications including trap depth, q-parameter, secular frequency, and ion height. Then, we present a numerical-simulation-based design procedure, which involves determining the basic assumptions, determining the shape and size of the chip, designing the dimensions of the radio frequency (RF) electrode, and analyzing the direct current (DC) control voltages. As an example of this design procedure, we present a case study with tutorial-like explanations. The proposed design procedure can provide a practical guideline for designing the electrodes of surface ion traps. PMID:27136559

  17. Control of the conformations of ion Coulomb crystals in a Penning trap

    PubMed Central

    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

  18. Resonance excitation of ions stored in a quadrupole ion trap. Part IV. Theory of quadrupolar excitation

    NASA Astrophysics Data System (ADS)

    Alfred, Roland L.; Londry, Frank A.; March, Raymond E.

    1993-06-01

    A new theoretical treatment is presented for quadrupolar resonance excitation of ions stored in a quadrupole ion trap. When the ratio of the tickle voltage amplitude to that of the drive potential is small, the equation of ion motion can be expressed in the form of a perturbation series. Exact and approximate solutions to the first-order perturbation eqations are presented. Ion trajectories calculated from these solutions are compared with those calculated by numerical integration. The resonance conditions were found to correspond to a series of angular frequencies given by [omega]u,n = n + [beta]u - [infinity] < n < [infinity]. Some of these, [beta]z[Omega], (1 + [beta]z)[Omega](1 - [beta]z)[Omega] [beta],[Omega], had been observed previously in simulation studies.

  19. A monolithic array of three-dimensional ion traps fabricated with conventional semiconductor technology.

    PubMed

    Wilpers, Guido; See, Patrick; Gill, Patrick; Sinclair, Alastair G

    2012-09-01

    The coherent control of quantum-entangled states of trapped ions has led to significant advances in quantum information, quantum simulation, quantum metrology and laboratory tests of quantum mechanics and relativity. All of the basic requirements for processing quantum information with arrays of ion-based quantum bits (qubits) have been proven in principle. However, so far, no more than 14 ion-based qubits have been entangled with the ion-trap approach, so there is a clear need for arrays of ion traps that can handle a much larger number of qubits. Traps consisting of a two-dimensional electrode array have undergone significant development, but three-dimensional trap geometries can create a superior confining potential. However, existing three-dimensional approaches, as used in the most advanced experiments with trap arrays, cannot be scaled up to handle greatly increased numbers of ions. Here, we report a monolithic three-dimensional ion microtrap array etched from a silica-on-silicon wafer using conventional semiconductor fabrication technology. We have confined individual (88)Sr(+) ions and strings of up to 14 ions in a single segment of the array. We have measured motional frequencies, ion heating rates and storage times. Our results demonstrate that it should be possible to handle several tens of ion-based qubits with this approach. PMID:22820742

  20. Resonant oscillation modes of sympathetically cooled ions in a radio-frequency trap

    SciTech Connect

    Hasegawa, Taro; Shimizu, Tadao

    2002-12-01

    Sympathetic cooling of Ca{sup +}, Zn{sup +}, Sr{sup +}, Ba{sup +}, and Yb{sup +} as guest ions with laser-cooled {sup 24}Mg{sup +} as host ions in a rf ion trap is carried out, and resonant frequencies of their motion in the trap potential are measured. Various oscillation modes of the sympathetically cooled ions are observed. The resonant frequency of the oscillation mode is different from the frequency of either the collective oscillation frequency of the trapped ions or the oscillation frequency of each ion without host ions. This difference is well explained by a theoretical model in which coupled equations of motion of the host ion cloud with a single guest ion are considered.

  1. a Novel Method to Measure Spectra of Cold Molecular Ions

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Satrajit; Holz, Mathias; Campbell, Ewen; Banerjee, Agniva; Gerlich, Dieter; Maier, John P.

    2014-06-01

    A universal method has been developed in our group for measuring the spectra of molecular ions in a 22-pole radio frequency trap at low temperatures. It is based on laser induced inhibition of complex growth (LIICG)1. At low temperatures and high number densities of buffer gas, helium attaches to ions via ternary association. The formation of these weakly bound complexes, however, is inhibited following resonant absorption of the bare molecular ion. The first successful measurements have been demonstrated on the A 2Π_u ← X ^2Σ_g^+ electronic transition of N_2^+, with some thousand N_2^+ ions, helium densities of 1015 cm-3, and storage times of 1 s. The reduction in the number of N_2+-He complexes is the result of an interplay between excitation, radiative and collisional cooling, ternary association, and collision induced dissociation, and is explained using a kinetic model. The method is also applicable to larger molecular species. In this case internal conversion following electronic excitation produces internally "hot" ions, reducing the attachment of helium. The technique is universal because complex formation can be impeded over a wide wavelength range. [1] S. Chakrbarty, M. Holz, E. K. Campbell, A. Banerjee, D. Gerlich, and J. P. Maier, J. Phys. Chem. Lett. 2013, 4, 4051.

  2. Velocity diffusion and radiation trapping force in a one-dimensional expansion of cold atomic clouds in a magneto-optical trap

    SciTech Connect

    Pradhan, S.; Mayya, Y. S.; Jagatap, B. N.

    2007-09-15

    We experimentally investigate one-dimensional (1D) expansion of a cold cloud of cesium atoms in orthogonal 2D configuration of near resonant laser beams by temporally modulating a pair of counterpropagating trapping beams of a magneto-optical trap (MOT). The cloud is observed to undergo ballistic expansion followed by superballistic explosive growth due to the fluctuations of the 2D radiation force. A model based on the theory of Brownian motion is developed and a comparison of experiments with theory is shown to provide a direct measure of the velocity diffusion coefficient. We also observe sudden contraction of the cloud immediately after switching off the pair of trapping beams, which provides direct evidence for the existence of the radiation trapping force in a MOT.

  3. Infrared ion spectroscopy in a modified quadrupole ion trap mass spectrometer at the FELIX free electron laser laboratory

    NASA Astrophysics Data System (ADS)

    Martens, Jonathan; Berden, Giel; Gebhardt, Christoph R.; Oomens, Jos

    2016-10-01

    We report on modifications made to a Paul-type quadrupole ion trap mass spectrometer and discuss its application in infrared ion spectroscopy experiments. Main modifications involve optical access to the trapped ions and hardware and software coupling to a variety of infrared laser sources at the FELIX infrared free electron laser laboratory. In comparison to previously described infrared ion spectroscopy experiments at the FELIX laboratory, we find significant improvements in efficiency and sensitivity. Effects of the trapping conditions of the ions on the IR multiple photon dissociation spectra are explored. Enhanced photo-dissociation is found at lower pressures in the ion trap. Spectra obtained under reduced pressure conditions are found to more closely mimic those obtained in the high-vacuum conditions of an Fourier transform ion cyclotron resonance mass spectrometer. A gas-mixing system is described enabling the controlled addition of a secondary gas into helium buffer gas flowing into the trap and allows for ion/molecule reactions in the trap. The electron transfer dissociation (ETD) option of the mass spectrometer allows for IR structure characterization of ETD-generated peptide dissociation products.

  4. Penning traps with unitary architecture for storage of highly charged ions.

    PubMed

    Tan, Joseph N; Brewer, Samuel M; Guise, Nicholas D

    2012-02-01

    Penning traps are made extremely compact by embedding rare-earth permanent magnets in the electrode structure. Axially-oriented NdFeB magnets are used in unitary architectures that couple the electric and magnetic components into an integrated structure. We have constructed a two-magnet Penning trap with radial access to enable the use of laser or atomic beams, as well as the collection of light. An experimental apparatus equipped with ion optics is installed at the NIST electron beam ion trap (EBIT) facility, constrained to fit within 1 meter at the end of a horizontal beamline for transporting highly charged ions. Highly charged ions of neon and argon, extracted with initial energies up to 4000 eV per unit charge, are captured and stored to study the confinement properties of a one-magnet trap and a two-magnet trap. Design considerations and some test results are discussed.

  5. Ion irradiation of graphene on Ir(111): From trapping to blistering

    NASA Astrophysics Data System (ADS)

    Herbig, Charlotte; Åhlgren, E. Harriet; Valerius, Philipp; Schröder, Ulrike A.; Martínez-Galera, Antonio J.; Arman, Mohammad A.; Kotakoski, Jani; Knudsen, Jan; Krasheninnikov, Arkady V.; Michely, Thomas

    Graphene grown epitaxially on Ir(111) is irradiated with low energy noble gas ions and the processes induced by atomic collision and subsequent annealing are analyzed using scanning tunneling microscopy, low energy electron diffraction, X-ray photoelectron diffraction and thermal desorption spectroscopy. Upon room temperature ion irradiation graphene amorphizes and recovers its crystalline structure during annealing. The energetic noble gas projectiles are trapped with surprisingly high efficiency under the graphene cover up to extremely high temperatures beyond 1300K. The energy, angle, and ion species dependence of trapping are quantified. At elevated temperatures the trapped gas forms well developed and highly pressurized blisters under the graphene cover. We use molecular dynamics simulations and ab initio calculations to elucidate the trapping mechanism and its thermal robustness. Similar trapping and blistering are observed after ion irradiation of a single layer of hexagonal boron nitride on Ir(111) and we speculate on the generality of the observed phenomena.

  6. Expansion Discharge Source for Ion Beam Laser Spectroscopy of Cold Molecular Ions

    NASA Astrophysics Data System (ADS)

    Porambo, Michael; Pearson, Jessica; Riccardo, Craig; McCall, Benjamin J.

    2013-06-01

    Molecular ions are important in several fields of research, and spectroscopy acts as a key tool in the study of these ions. However, problems such as low ion abundance, ion-neutral confusion, and spectral congestion due to high internal temperatures can hinder effective spectroscopic studies. To circumvent these problems, we are developing a technique called Sensitive, Cooled, Resolved, Ion BEam Spectroscopy (SCRIBES). This ion beam spectrometer will feature a continuous supersonic expansion discharge source to produce cold molecular ions, electrostatic ion optics to focus the ions into an ion beam and bend the beam away from co-produced neutral molecules, an overlap region for cavity enhanced spectroscopy, and a time-of-flight mass spectrometer. When completed, SCRIBES will be an effective tool for the study of large, fluxional, and complex molecular ions that are difficult to study with other means. The ion beam spectrometer has been successfully implemented with a hot ion source. This talk will focus on the work of integrating a supersonic expansion discharge source into the instrument. To better understand how the source would work in the whole ion beam instrument, characterization studies are being performed with spectroscopy of HN_2^+ in a section of the system to ascertain the rotational temperature of the ion expansion. Attempts are also underway to measure the ion current from a beam formed from the expansion. Once the source in this environment is properly understood, we will reintegrate it to the rest of the ion beam system, completing SCRIBES. A. A. Mills, B. M. Siller, M. W. Porambo, M. Perera, H. Kreckel and B. J. McCall J. Chem. Phys., 135, 224201, (2011). K. N. Crabtree, C. A. Kauffman and B. J. McCall Rev. Sci. Instrum. 81, 086103, (2010).

  7. Development of a compact cold-atom atomic clock based on coherent population trapping

    NASA Astrophysics Data System (ADS)

    Blanshan, Eric M.

    Field-grade atomic clocks capable of primary standard performance in compact physics packages would be of significant value in a variety of applications ranging from network synchronization and secure communications to GPS hold-over and inertial navigation. A cold-atom coherent population trapping (CACPT) clock featuring laser-cooled atoms and pulsed Ramsey interrogation is a strong candidate for this technology if the principal frequency shifts can be controlled and the performance degradation associated with miniaturization can be overcome. In this thesis, research focused on the development of this type of compact atomic clock is presented. To address the low atom numbers obtained in small cold-atom sources, experiments were performed in which an atomic beam was decelerated with bichromatic stimulated laser forces and loaded into a mm-scale magneto-optical trap, increasing the atom number by a factor of 12.5. A CACPT clock using the high-contrast lin||lin optical interrogation technique was developed and achieved a stability of 7 x 10-13 after one hour of integration. Doppler shifts in the clock are explained using a simple kinematic model and canceled by interrogating the atoms with a counter-propagating CPT configuration. Finally, a thorough characterization of the AC-stark effect in lin||lin CPT was performed. Observed shifts are explained in terms of contributions from coherent CPT-generating couplings and population transfer effects caused by optical pumping from incoherent light. Measurements are compared with existing and new theoretical treatments, and a laser configuration is identified that reduces clock drift from light shifts to less than 10-14 for the current system.

  8. A hand-portable digital linear ion trap mass spectrometer.

    PubMed

    Xue, Bing; Sun, Lulu; Huang, Zhengxu; Gao, Wei; Fan, Rongrong; Cheng, Ping; Ding, Li; Ma, Li; Zhou, Zhen

    2016-10-01

    A hand-portable digital linear ion trap mass spectrometer (DLIT-MS) has been developed for VOC analysis. It has a weight of 18 kg with dimensions of 49 cm × 39 cm × 16 cm, and consumes an average power of ca. 60 W. As a result of the introduction of a digital waveform, the DLIT-MS can be driven at a lower voltage (±100 V) to cover a mass range of 30-300 Th with a unit resolution. Compact electronics has been designed to control the DLIT-MS and record mass spectra. The mass drift was reduced after the improvement in electronics to stabilize the digital waveform voltage during the mass scan. Tandem mass spectrometry (MS) has been achieved by using digital asymmetric waveform isolation (DAWI), forward and reverse scan, and collision induced dissociation (CID). The isolation and CID efficiency for methyl salicylate were 83.9% and 81.3%, respectively. A novel buffer gas inlet system was designed to enhance the sensitivity and allow easy and safe use of the instrument. Limits of detection below 1 ppbv were obtained for several mixed gaseous samples. PMID:27396834

  9. A hand-portable digital linear ion trap mass spectrometer.

    PubMed

    Xue, Bing; Sun, Lulu; Huang, Zhengxu; Gao, Wei; Fan, Rongrong; Cheng, Ping; Ding, Li; Ma, Li; Zhou, Zhen

    2016-10-01

    A hand-portable digital linear ion trap mass spectrometer (DLIT-MS) has been developed for VOC analysis. It has a weight of 18 kg with dimensions of 49 cm × 39 cm × 16 cm, and consumes an average power of ca. 60 W. As a result of the introduction of a digital waveform, the DLIT-MS can be driven at a lower voltage (±100 V) to cover a mass range of 30-300 Th with a unit resolution. Compact electronics has been designed to control the DLIT-MS and record mass spectra. The mass drift was reduced after the improvement in electronics to stabilize the digital waveform voltage during the mass scan. Tandem mass spectrometry (MS) has been achieved by using digital asymmetric waveform isolation (DAWI), forward and reverse scan, and collision induced dissociation (CID). The isolation and CID efficiency for methyl salicylate were 83.9% and 81.3%, respectively. A novel buffer gas inlet system was designed to enhance the sensitivity and allow easy and safe use of the instrument. Limits of detection below 1 ppbv were obtained for several mixed gaseous samples.

  10. Experimental simulation and limitations of quantum walks with trapped ions

    NASA Astrophysics Data System (ADS)

    Matjeschk, R.; Schneider, Ch; Enderlein, M.; Huber, T.; Schmitz, H.; Glueckert, J.; Schaetz, T.

    2012-03-01

    We examine the prospects of discrete quantum walks (QWs) with trapped ions. In particular, we analyze in detail the limitations of the protocol of Travaglione and Milburn (2002 Phys. Rev. A 65 032310) that has been implemented by several experimental groups in recent years. Based on the first realization in our group (Schmitz et al 2009 Phys. Rev. Lett. 103 090504), we investigate the consequences of leaving the scope of the approximations originally made, such as the Lamb-Dicke approximation. We explain the consequential deviations from the idealized QW for different experimental realizations and an increasing number of steps by taking into account higher-order terms of the quantum evolution. It turns out that these already become significant after a few steps, which is confirmed by experimental results and is currently limiting the scalability of this approach. Finally, we propose a new scheme using short laser pulses, derived from a protocol from the field of quantum computation. We show that this scheme is not subject to the above-mentioned restrictions and analytically and numerically evaluate its limitations, based on a realistic implementation with our specific setup. Implementing the protocol with state-of-the-art techniques should allow for substantially increasing the number of steps to 100 and beyond and should be extendable to higher-dimensional QWs.

  11. Calorimetric Low-Temperature Detectors for X-Ray Spectroscopy on Trapped Highly-Charged Heavy Ions

    NASA Technical Reports Server (NTRS)

    Kilbourne, Caroline; Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Ilieva, S.; Kilbourne, C.; McCammon, D.

    2012-01-01

    The application of Calorimetric Low-Temperature Detectors (CLTDs) has been proposed at the Heavy-Ion TRAP facility HITRAP which is currently being installed at the Helmholtz Research Center for Heavy Ion Research GSI. This cold ion trap setup will allow the investigation of X-rays from ions practically at rest, for which the excellent energy resolution of CLTDs can be used to its full advantage. However, the relatively low intensities at HITRAP demand larger solid angles and an optimized cryogenic setup. The influence of external magnetic fields has to be taken into account. CLTDs will also be a substantial part of the instrumental equipment at the future Facility for Antiproton and Heavy Ion Research (FAIR), for which a wide variety of high-precision X-ray spectroscopy experiments has been proposed. This contribution will give an overview on the chances and challenges for the application of CLTDs at HITRAP as well as perspectives for future experiments at the FAIR facility.

  12. Ion Trap with Narrow Aperture Detection Electrodes for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Nagornov, Konstantin O.; Kozhinov, Anton N.; Tsybin, Oleg Y.; Tsybin, Yury O.

    2015-05-01

    The current paradigm in ion trap (cell) design for Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is the ion detection with wide aperture detection electrodes. Specifically, excitation and detection electrodes are typically 90° wide and positioned radially at a similar distance from the ICR cell axis. Here, we demonstrate that ion detection with narrow aperture detection electrodes (NADEL) positioned radially inward of the cell's axis is feasible and advantageous for FT-ICR MS. We describe design details and performance characteristics of a 10 T FT-ICR MS equipped with a NADEL ICR cell having a pair of narrow aperture (flat) detection electrodes and a pair of standard 90° excitation electrodes. Despite a smaller surface area of the detection electrodes, the sensitivity of the NADEL ICR cell is not reduced attributable to improved excite field distribution, reduced capacitance of the detection electrodes, and their closer positioning to the orbits of excited ions. The performance characteristics of the NADEL ICR cell are comparable with the state-of-the-art FT-ICR MS implementations for small molecule, peptide, protein, and petroleomics analyses. In addition, the NADEL ICR cell's design improves the flexibility of ICR cells and facilitates implementation of advanced capabilities (e.g., quadrupolar ion detection for improved mainstream applications). It also creates an intriguing opportunity for addressing the major bottleneck in FTMS—increasing its throughput via simultaneous acquisition of multiple transients or via generation of periodic non-sinusoidal transient signals.

  13. Secondary Ion Mass Spectrometry of Zeolite Materials: Observation of Abundant Aluminosilicate Oligomers Using an Ion Trap

    SciTech Connect

    Groenewold, Gary Steven; Kessinger, Glen Frank; Scott, Jill Rennee; Gianotto, Anita Kay; Appelhans, Anthony David; Delmore, James Edward

    2000-12-01

    Oligomeric oxyanions were observed in the secondary ion mass spectra (SIMS) of zeolite materials. The oxyanions have the general composition AlmSinO2(m+n)H(m-1)- (m + n = 2 to 8) and are termed dehydrates. For a given mass, multiple elemental compositions are possible because (Al + H) is an isovalent and isobaric substitute for Si. Using 18 keV Ga+ as a projectile, oligomer abundances are low relative to the monomers. Oligomer abundance can be increased by using the polyatomic projectile ReO4- (~5 keV). Oligomer abundance can be further increased using an ion trap (IT-) SIMS; in this instrument, long ion lifetimes (tens of ms) and relatively high He pressure result in significant collisional stabilization and increased high-mass abundance. The dehydrates rapidly react with adventitious H2O present in the IT-SIMS to form mono-, di-, and trihydrates. The rapidity of the reaction and comparison to aluminum oxyanion hydration suggest that H2O adds to the aluminosilicate oxyanions in a dissociative fashion, forming covalently bound product ions. In addition to these findings, it was noted that production of abundant oligomeric aluminosilicates could be significantly increased by substituting the countercation (NH4+) with the larger alkali ions Rb+ and Cs+. This constitutes a useful tactic for generating large aluminosilicate oligomers for surface characterization and ion-molecule reactivity studies.

  14. Experimental system design for the integration of trapped-ion and superconducting qubit systems

    NASA Astrophysics Data System (ADS)

    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.

    2016-07-01

    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.

  15. UV and IR spectroscopy of cold 1,2-dimethoxybenzene complexes with alkali metal ions.

    PubMed

    Inokuchi, Yoshiya; Boyarkin, Oleg V; Ebata, Takayuki; Rizzo, Thomas R

    2012-04-01

    We report UV photodissociation (UVPD) and IR-UV double-resonance spectra of 1,2-dimethoxybenzene (DMB) complexes with alkali metal ions, M(+)·DMB (M = Li, Na, K, Rb, and Cs), in a cold, 22-pole ion trap. The UVPD spectrum of the Li(+) complex shows a strong origin band. For the K(+)·DMB, Rb(+)·DMB, and Cs(+)·DMB complexes, the origin band is very weak and low-frequency progressions are much more extensive than that of the Li(+) ion. In the case of the Na(+)·DMB complex, spectral features are similar to those of the K(+), Rb(+), and Cs(+) complexes, but vibronic bands are not resolved. Geometry optimization with density functional theory indicates that the metal ions are bonded to the oxygen atoms in all the M(+)·DMB complexes. For the Li(+) complex in the S(0) state, the Li(+) ion is located in the same plane as the benzene ring, while the Na(+), K(+), Rb(+), and Cs(+) ions are located off the plane. In the S(1) state, the Li(+) complex has a structure similar to that in the S(0) state, providing the strong origin band in the UV spectrum. In contrast, the other complexes show a large structural change in the out-of-plane direction upon S(1)-S(0) excitation, which results in the extensive low-frequency progressions in the UVPD spectra. For the Na(+)·DMB complex, fast charge transfer occurs from Na(+) to DMB after the UV excitation, making the bandwidth of the UVPD spectrum much broader than that of the other complexes and producing the photofragment DMB(+) ion.

  16. Trapped-ion quantum logic gates based on oscillating magnetic fields.

    PubMed

    Ospelkaus, C; Langer, C E; Amini, J M; Brown, K R; Leibfried, D; Wineland, D J

    2008-08-29

    Oscillating magnetic fields and field gradients can be used to implement single-qubit rotations and entangling multiqubit quantum gates for trapped-ion quantum information processing (QIP). With fields generated by currents in microfabricated surface-electrode traps, it should be possible to achieve gate speeds that are comparable to those of optically induced gates for realistic distances between the ion crystal and the electrode surface. Magnetic-field-mediated gates have the potential to significantly reduce the overhead in laser-beam control and motional-state initialization compared to current QIP experiments with trapped ions and will eliminate spontaneous scattering, a fundamental source of decoherence in laser-mediated gates.

  17. Radial transport of energetic ions in the presence of trapped electron mode turbulence

    SciTech Connect

    Chowdhury, J.; Wang, W.; Ethier, S.; Manickam, J.; Ganesh, R.

    2011-11-15

    The nature of transport of hot ions is studied in the presence of microturbulence generated by the trapped electron mode in a Tokamak using massively parallel, first principle based global nonlinear gyrokinetic simulation, and with the help of a passive tracer method. Passing and trapped hot ions are observed to exhibit inverse and inverse square scaling with energy, while those with isotropic pitch distribution are found to exhibit inverse dependence on energy. For all types of hot ions, namely, isotropic, passing, and trapped, the radial transport appears to be subdiffusive for the parameters considered.

  18. Controlled collisions of a single atom and an ion guided by movable trapping potentials

    SciTech Connect

    Idziaszek, Zbigniew; Calarco, Tommaso; Zoller, Peter

    2007-09-15

    We consider a system composed of a trapped atom and a trapped ion. The ion charge induces in the atom an electric dipole moment, which attracts it with an r{sup -4} dependence at large distances. In the regime considered here, the characteristic range of the atom-ion interaction is comparable or larger than the characteristic size of the trapping potential, which excludes the application of the contact pseudopotential. The short-range part of the interaction is described in the framework of quantum-defect theory, by introducing some short-range parameters, which can be related to the s-wave scattering length. When the separation between traps is changed we observe trap-induced shape resonances between molecular bound states and vibrational states of the external trapping potential. Our analysis is extended to quasi-one-dimensional geometries, when the scattering exhibit confinement-induced resonances, similar to the ones studied before for short-range interactions. For quasi-one-dimensional systems we investigate the effects of coupling between the center of mass and relative motion, which occurs for different trapping frequencies of atom and ion traps. Finally, we show how the two types of resonances can be employed for quantum state control and spectroscopy of atom-ion molecules.

  19. Assembling a ring-shaped crystal in a microfabricated surface ion trap

    DOE PAGES

    Stick, Daniel Lynn; Tabakov, Boyan; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; Sterk, Jonathan D.; Tigges, Chris

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

  20. Lifetime measurements in an electrostatic ion beam trap using image charge monitoring

    SciTech Connect

    Rahinov, Igor; Toker, Yoni; Heber, Oded; Rappaport, Michael; Zajfman, Daniel; Strasser, Daniel; Schwalm, Dirk

    2012-03-15

    A technique for mass-selective lifetime measurements of keV ions in a linear electrostatic ion beam trap is presented. The technique is based on bunching the ions using a weak RF potential and non-destructive ion detection by a pick-up electrode. This method has no mass-limitation, possesses the advantage of inherent mass-selectivity, and offers a possibility of measuring simultaneously the lifetimes of different ion species with no need for prior mass-selection.

  1. The JPL Hg(sup +) Extended Linear Ion Trap Frequency Standard: Status, Stability, and Accuracy Prospects

    NASA Technical Reports Server (NTRS)

    Tjoelker, R. L.; Prestage, J. D.; Maleki, L.

    1996-01-01

    Microwave frequency standards based on room temperature (sup 199)Hg(sup +) ions in a Linear Ion Trap (LITS) presently achieve a Signal to Noise and line Q inferred short frequency stability. Long term stability has been measured for averaging intervals up to 5 months with apparent sensitivity to variations in ion number/temperature limiting the flicker floor.

  2. Production of Ar{sup q+} ions with a tandem linear Paul trap

    SciTech Connect

    Higaki, H. Nagayasu, K.; Iwai, T.; Ito, K.; Okamoto, H.

    2015-06-29

    A tandem linear Paul trap was used to create highly charged Argon ions by electron impact ionizations. By improving the operation scheme, the production of Ar{sup 4+} ions was confirmed. Possible improvements for the future experiments with laser cooled Ca{sup +} ions are suggested.

  3. Sisyphus cooling of Trapped Ions as a Route to Experiments in the Quantum Regime

    NASA Astrophysics Data System (ADS)

    Haljan, Paul C.; Ejtemaee, Sara

    2016-05-01

    In a linear rf Paul trap, relaxing the transverse confinement can lead laser-cooled trapped ions to undergo a symmetry-breaking structural transition from a linear to a 2-D zigzag configuration. We are interested in exploring the dynamics near the linear-zigzag transition at ultralow temperatures, corresponding to a few quanta or less of thermal energy in the vibrations of the trapped ion crystal. In weaker traps, as in our case, the Lamb-Dicke limit is not strongly fulfilled through Doppler cooling, and Raman sideband cooling of the vibrational modes starting from Doppler temperatures becomes challenging. To resolve this, we have implemented 3-D Sisyphus cooling based on a polarization gradient field as an intermediate step to achieving near ground-state cooling of trapped Ytterbium ions. We have compared the performance of the polarization-gradient cooling of a single trapped ion to simulations, and have extended the technique to cool crystals of a few ions. We find Sisyphus cooling, which has so far not been widely used with trapped ions, to be a simple, robust technique that simultaneously cools all of the vibrational modes to well below the Doppler limit, and paves the way towards our experiments in the quantum regime.

  4. Ion Funnel Trap Interface for Orthogonal Time-of-Flight Mass Spectrometry

    SciTech Connect

    Ibrahim, Yehia M.; Belov, Mikhail E.; Tolmachev, Aleksey V.; Prior, David C.; Smith, Richard D.

    2007-10-15

    A combined electrodynamic ion funnel and ion trap coupled to an orthogonal acceleration (oa)-time-of-flight mass spectrometer was developed and characterized. The ion trap was incorporated through the use of added terminal electrodynamic ion funnel electrodes enabling control over the axial dc gradient in the trap section. The ion trap operates efficiently at a pressure of ~1 Torr, and measurements indicate a maximum charge capacity of ~3 × 107 charges. An order of magnitude increase in sensitivity was observed in the analysis of low concentration peptides mixtures with orthogonal acceleration (oa)-time-of-flight mass spectrometry (oa-TOF MS) in the trapping mode as compared to the continuous regime. A signal increase in the trapping mode was accompanied by reduction in the chemical background, due to more efficient desolvation of, for example, solvent related clusters. Controlling the ion trap ejection time was found to result in efficient removal of singly charged species and improving signal-to-noise ratio (S/N) for the multiply charged analytes.

  5. Versatile cold atom target apparatus

    SciTech Connect

    Goetz, Simone; Hoeltkemeier, Bastian; Hofmann, Christoph S.; Litsch, Dominic; DePaola, Brett D.; Weidemueller, Matthias

    2012-07-15

    We report on a compact and transportable apparatus that consists of a cold atomic target at the center of a high resolution recoil ion momentum spectrometer. Cold rubidium atoms serve as a target which can be operated in three different modes: in continuous mode, consisting of a cold atom beam generated by a two-dimensional magneto-optical trap, in normal mode in which the atoms from the beam are trapped in a three-dimensional magneto-optical trap (3D MOT), and in high density mode in which the 3D MOT is operated in dark spontaneous optical trap configuration. The targets are characterized using photoionization.

  6. Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons

    NASA Astrophysics Data System (ADS)

    Alinejad, H.; Sobhanian, S.; Mahmoodi, J.

    2006-01-01

    A theoretical investigation has been made for ion-acoustic waves in an unmagnetized electron-positron-ion plasma. A more realistic situation in which plasma consists of a negatively charged ion fluid, free positrons, and trapped as well as free electrons is considered. The properties of stationary structures are studied by the reductive perturbation method, which is valid for small but finite amplitude limit, and by pseudopotential approach, which is valid for large amplitude. With an appropriate modified form of the electron number density, two new equations for the ion dynamics have been found. When deviations from isothermality are finite, the modified Korteweg-deVries equation has been found, and for the case that deviations from isothermality are small, calculations lead to a generalized Korteweg-deVries equation. It is shown from both weakly and highly nonlinear analysis that the presence of the positrons may allow solitary waves to exist. It is found that the effect of the positron density changes the maximum value of the amplitude and M (Mach number) for which solitary waves can exist. The present theory is applicable to analyze arbitrary amplitude ion-acoustic waves associated with positrons which may occur in space plasma.

  7. Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons

    SciTech Connect

    Alinejad, H.; Sobhanian, S.; Mahmoodi, J.

    2006-01-15

    A theoretical investigation has been made for ion-acoustic waves in an unmagnetized electron-positron-ion plasma. A more realistic situation in which plasma consists of a negatively charged ion fluid, free positrons, and trapped as well as free electrons is considered. The properties of stationary structures are studied by the reductive perturbation method, which is valid for small but finite amplitude limit, and by pseudopotential approach, which is valid for large amplitude. With an appropriate modified form of the electron number density, two new equations for the ion dynamics have been found. When deviations from isothermality are finite, the modified Korteweg-deVries equation has been found, and for the case that deviations from isothermality are small, calculations lead to a generalized Korteweg-deVries equation. It is shown from both weakly and highly nonlinear analysis that the presence of the positrons may allow solitary waves to exist. It is found that the effect of the positron density changes the maximum value of the amplitude and M (Mach number) for which solitary waves can exist. The present theory is applicable to analyze arbitrary amplitude ion-acoustic waves associated with positrons which may occur in space plasma.

  8. Ion-neutral chemistry at ultralow energies:Dynamics of reactive collisions between laser-cooled Ca+ or Ba+ ions and Rb atoms in an ion-atom hybrid trap

    NASA Astrophysics Data System (ADS)

    Dulieu, O.; Hall, F. H. J.; Eberle, P.; Hegi, G.; Raoult, M.; Aymar, M.; Willitsch, S.

    2013-05-01

    Cold chemical reactions between laser-cooled Ca+ or Ba+ ions and Rb atoms were studied in an ion-atom hybrid trap. Reaction rate constants were determined in the collision energy range Ecoll /kB = 20 mK-20 K. Product branching ratios were studied using resonant-excitation mass spectrometry. The dynamics of the reactive processes including the radiative formation of CaRb+ and BaRb+ molecular ions has been analyzed using accurate potential energy curves and quantum-scattering calculations for the radiative channels. It is shown that the energy dependence of the reaction rates is governed by long-range interactions, while its magnitude is determined by short-range non-adiabatic and radiative couplings. The quantum character of the collisions is predicted to manifest itself in the occurrence of narrow shape resonances at well-defined collision energies. The present results highlight both universal and system-specific phenomena in cold ion-neutral collisions. This work was supported by the Swiss National Science Foundation and the COST Action ''Ion Traps for Tomorrow's Applications''.

  9. A carbon-cluster laser ion source for TRIGA-TRAP

    NASA Astrophysics Data System (ADS)

    Smorra, C.; Blaum, K.; Eberhardt, K.; Eibach, M.; Ketelaer, J.; Ketter, J.; Knuth, K.; Nagy, Sz

    2009-08-01

    A new laser ablation ion source was developed and tested for the Penning trap mass spectrometer TRIGA-TRAP in order to provide carbon-cluster ions for absolute mass calibration. Ions of different cluster sizes up to C+24 were successfully produced, covering the mass range up to the heavy actinide elements. The ions were captured in a Penning trap, and their time-of-flight cyclotron resonances recorded in order to determine their cyclotron frequency. Furthermore, the same ion source was used to produce GdO+ ions from a gadolinium target in sufficient amount for mass spectrometry purposes. The design of the source and its characteristics are presented. This paper comprises partly the PhD theses of J Ketelaer and C Smorra.

  10. Cascade emission in electron beam ion trap plasma of W25+ ion

    NASA Astrophysics Data System (ADS)

    Jonauskas, V.; Pütterich, T.; Kučas, S.; Masys, Š.; Kynienė, A.; Gaigalas, G.; Kisielius, R.; Radžiūtė, L.; Rynkun, P.; Merkelis, G.

    2015-07-01

    Spectra of the W25+ ion are studied using the collisional-radiative model (CRM) with an ensuing cascade emission. It is determined that the cascade emission boosts intensities only of a few lines in the 10-30 nm range. The cascade emission is responsible for the disappearance of structure of lines at about 6 nm in the electron beam ion trap plasma. Emission band at 4.5-5.3 nm is also affected by the cascade emission. The strongest lines in the CRM spectrum correspond to 4d9 4f4 → 4f3 transitions, while 4f2 5 d → 4f3 transitions arise after the cascade emission is taken into account.

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

    PubMed

    Cornejo, J M; Colombano, M; Doménech, J; Block, M; Delahaye, P; Rodríguez, D

    2015-10-01

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

  12. in situ plasma removal of surface contaminants from ion trap electrodes

    SciTech Connect

    Haltli, Raymond A.

    2015-04-01

    This research resulted in a construction and implementation of an in situ plasma discharge to remove surface contaminants from electrodes in an ion trapping experimental system is presented with results.

  13. Miniaturized gas chromatograph-Paul ion trap system: applications to environmental monitoring

    NASA Technical Reports Server (NTRS)

    Shortt, B. J.; Darrach, M. R.; Holland, Paul M.; Chutjian, A.

    2004-01-01

    A miniature gas chromatograph (GC) and miniature Paul ion trap (PT) mass spectrometer system has been developed for identifying and quantifying chemical species present in closed environments having a complex mixture of gases.

  14. Measurement of ion motional heating rates over a range of trap frequencies and temperatures

    NASA Astrophysics Data System (ADS)

    Bruzewicz, C. D.; Sage, J. M.; Chiaverini, J.

    2015-04-01

    We present measurements of the motional heating rate of a trapped ion at different trap frequencies and temperatures between ˜0.6 and 1.5 MHz and ˜4 and 295 K. Additionally, we examine the possible effect of adsorbed surface contaminants with boiling points below ˜105 ∘C by measuring the ion heating rate before and after locally baking our ion trap chip under ultrahigh vacuum conditions. We compare the heating rates presented here to those calculated from available electric-field noise models. We can tightly constrain a subset of these models based on their expected frequency and temperature scaling interdependence. Discrepancies between the measured results and predicted values point to the need for refinement of theoretical noise models in order to more fully understand the mechanisms behind motional trapped-ion heating.

  15. Development and Characterization of a Ytterbium-171 Miniature Ion Trap Frequency Standard

    NASA Astrophysics Data System (ADS)

    Partner, Heather L.

    This dissertation reports on the development of a low-power, high-stability miniature atomic frequency standard based on 171Yb+ ions. The ions are buffer-gas cooled and held in a linear quadrupole trap that is integrated into a sealed, getter-pumped vacuum package, and interrogated on the 12.6 GHz hyperfine transition. We hope to achieve a long-term fractional frequency stability of 10-14 with this miniature clock while consuming only 50 mW of power and occupying a volume of 5 cm 3, as part of a project funded to rapidly develop an advanced miniaturized frequency standard that has exceptional long-term stability. I discuss our progress through several years of development on this project. We began by building a relatively conventional tabletop clock system to act as a "test bed" for future components and for testing new techniques in a controlled environment. We moved on to develop and test several designs of miniature ion-trap vacuum packages, while also developing techniques for various aspects of the clock operation, including ion loading, laser and magnetic field stabilization, and a low power ion trap drive. The ion traps were modeled using boundary element software to assist with the design and parameter optimization of new trap geometries. We expect a novel trap geometry made using a material that is new to ion traps to lead to an exceptionally small ion trap vacuum package in the next phase of the project. To achieve the long-term stability required, we have also considered the sensitivity of the clock frequency to magnetic fields. A study of the motion of the individual ions in a room-temperature cloud in the trap was performed. The purpose of this simulation was to understand the effect of both spatially varying and constant magnetic fields on the clock resonance and therefore the operation of the clock. These effects were studied experimentally and theoretically for several traps. In summary, this dissertation is a contribution to the design, development

  16. Universal quantum computation in decoherence-free subspaces with hot trapped ions

    SciTech Connect

    Aolita, Leandro; Davidovich, Luiz; Kim, Kihwan; Haeffner, Hartmut

    2007-05-15

    We consider interactions that generate a universal set of quantum gates on logical qubits encoded in a collective-dephasing-free subspace, and discuss their implementations with trapped ions. This allows for the removal of the by-far largest source of decoherence in current trapped-ion experiments, collective dephasing. In addition, an explicit parametrization of all two-body Hamiltonians able to generate such gates without the system's state ever exiting the protected subspace is provided.

  17. Ultraviolet Photodissociation Induced by Light-Emitting Diodes in a Planar Ion Trap.

    PubMed

    Holden, Dustin D; Makarov, Alexander; Schwartz, Jae C; Sanders, James D; Zhuk, Eugene; Brodbelt, Jennifer S

    2016-09-26

    The first application of light-emitting diodes (LEDs) for ultraviolet photodissociation (UVPD) mass spectrometry is reported. LEDs provide a compact, low cost light source and have been incorporated directly into the trapping cell of an Orbitrap mass spectrometer. MS/MS efficiencies of over 50 % were obtained using an extended irradiation period, and UVPD was optimized by modulating the ion trapping parameters to maximize the overlap between the ion cloud and the irradiation volume.

  18. Instability due to trapped electrons in magnetized multi-ion dusty plasmas

    NASA Astrophysics Data System (ADS)

    Haider, M. M.; Ferdous, T.; Duha, S. S.

    2015-05-01

    An attempt has been made to find out the effects of trapped electrons in dust-ion-acoustic solitary waves in magnetized multi-ion plasmas, as in most space plasmas, the hot electrons follow the trapped/vortex-like distribution. To do so, we have derived modified Zakharov-Kuznetsov equation using reductive perturbation method and its solution. A small- perturbation technique was employed to find out the instability criterion and growth rate of such a wave.

  19. Ultraviolet Photodissociation Induced by Light-Emitting Diodes in a Planar Ion Trap.

    PubMed

    Holden, Dustin D; Makarov, Alexander; Schwartz, Jae C; Sanders, James D; Zhuk, Eugene; Brodbelt, Jennifer S

    2016-09-26

    The first application of light-emitting diodes (LEDs) for ultraviolet photodissociation (UVPD) mass spectrometry is reported. LEDs provide a compact, low cost light source and have been incorporated directly into the trapping cell of an Orbitrap mass spectrometer. MS/MS efficiencies of over 50 % were obtained using an extended irradiation period, and UVPD was optimized by modulating the ion trapping parameters to maximize the overlap between the ion cloud and the irradiation volume. PMID:27605434

  20. A new technique for unbiased external ion accumulation in a quadrupole two-dimensional ion trap for electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Belov, M E; Nikolaev, E N; Alving, K; Smith, R D

    2001-01-01

    External ion accumulation in a two-dimensional (2D) multipole trap has been shown to increase the sensitivity, dynamic range and duty cycle of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. However, it is important that trapped ions be detected without significant bias at longer accumulation times in the external 2D multipole trap. With increasing ion accumulation time pronounced m/z discrimination was observed when trapping ions in an accumulation quadrupole. In this work we show that superimposing lower rf-amplitude dipolar excitation over the main rf-field in the accumulation quadrupole results in disruption of the m/z discrimination and can potentially be used to achieve unbiased external ion accumulation with FTICR.

  1. Microfabrication of Surface Ion Trap Chip and State Manipulation of Single 171Yb+ Qubit

    NASA Astrophysics Data System (ADS)

    Hong, Seokjun; Lee, Minjae; Cheon, Hongjin; Ahn, Jun Sik; Kim, Taehyun; Cho, Dong-Il ``Dan''; ASRI/ISRC; Department of Electrical; Computer Engineering, Seoul National University Team; Quantum Tech. Lab., SK Telecom Team

    2015-05-01

    Ion traps are one of the promising physical implementations of quantum information processing. This paper presents new ion trap chips using a copper sacrificial layer. Boundary element method (BEM) simulation results show that the fabricated ion trap chip has a trap depth of 0.063 eV at 81 um above the top electrodes and radial secular frequencies of 1.52 and 1.6 MHz. Up to six 174Yb+ ions and three 171Yb+ ions have been successfully trapped. This paper also demonstrates the state manipulation of single 171Yb+ qubit through Rabi oscillation induced by microwave with frequency of 12.628 GHz. Using the new copper sacrificial method, accurate overhang dimensions that can effectively shield stray electric fields from dielectric layers, which in turn can reduce the micromotion of trapped ions, can be achieved. Acknowledgement: This work was partially supported by ICT R&D program of MSIP/IITP. [10043464, Development of quantum repeater technology for the application to communication systems].

  2. Successive Resonances for Ion Ejection at Arbitrary Frequencies in an Ion Trap

    NASA Astrophysics Data System (ADS)

    Snyder, Dalton T.; Cooks, R. Graham

    2016-09-01

    The use of successive resonances for ion ejection is demonstrated here as a method of scanning quadrupole ion traps with improvement in both resolution and sensitivity compared with single frequency resonance ejection. The conventional single frequency resonance ejection waveform is replaced with a dual-frequency waveform. The two included frequencies are spaced very closely and their relative amplitudes are adjusted so that the first frequency that ions encounter excites them to higher amplitudes where space charge effects are less prominent, thereby giving faster and more efficient ejection when the ions come into resonance with the second frequency. The method is applicable at any arbitrary frequency, unlike double and triple resonance methods. However, like double and triple resonance ejection, ejection using successive resonances requires the rf and AC waveforms to be phase-locked in order to retain mass accuracy and mass precision. The improved performance is seen in mass spectra acquired by rf amplitude scans (resonance ejection) as well as by secular frequency scans.

  3. Cold Fermi gas with inverse square interaction in a harmonic trap

    NASA Astrophysics Data System (ADS)

    Kulkarni, Manas; Abanov, Alexander G.

    2011-05-01

    We study equilibrium density and spin density profiles for a model of cold one-dimensional spin 1/2 fermions interacting via inverse square interaction and exchange in an external harmonic trap. This model is the well-known spin-Calogero model (sCM) and its fully nonlinear collective field theory description is known. We extend the field theory description to the presence of an external harmonic trap and obtain analytic results for statics and dynamics of the system. For instance, we find how the equilibrium density profile changes upon tuning the interaction strength. The results we obtain for equilibrium configurations are very similar to the ones obtained recently by Ma and Yang (2010) [1] for a model of fermions with short ranged interactions. Our main approximation is the neglect of the terms of higher order in spatial derivatives in equations of motion - gradientless approximation (Kulkarni et al., 2009) [2]. Within this approximation the hydrodynamic equations of motion can be written as a set of decoupled forced Riemann-Hopf equations for the dressed Fermi momenta of the model. This enables us to write analytical solutions for the dynamics of spin and charge. We describe the time evolution of the charge density when an initial non-equilibrium profile is created by cooling the gas with an additional potential in place and then suddenly removing the potential. We present our results as a simple "single-particle" evolution in the phase space reminiscing a similar description of the dynamics of noninteracting one-dimensional fermions.

  4. Beta decay measurements from 6He using an electrostatic ion beam trap

    NASA Astrophysics Data System (ADS)

    Aviv, O.; Vaintraub, S.; Hirsh, T.; Dhal, A.; Rappaport, M. L.; Melnik, D.; Heber, O.; Schwalm, D.; Zajfman, D.; Blaum, K.; Hass, M.

    2012-02-01

    We plan to establish the ground work of a novel experimental setup that will enable precision measurements of β-ν correlation from 6He using a unique method which incorporates a radioactive ion beam, ion trapping, ion bunching, and a radiation detection system. For the production of the 6He radioisotopes we plan to use neutron-induced reactions and an electron ion beam trap (EBIT) for ionization. The 6He+ radioisotopes will be stored in an electrostatic ion beam trap (EIBT), commonly used in atomic and molecular physics. The entire apparatus will be built at the Weizmann Institute. In the following we present the method, the present status of the setup and future plans.

  5. The laser ion source trap for highest isobaric selectivity in online exotic isotope productiona)

    NASA Astrophysics Data System (ADS)

    Schwellnus, F.; Blaum, K.; Catherall, R.; Crepieux, B.; Fedosseev, V.; Gottwald, T.; Kluge, H.-J.; Marsh, B.; Mattolat, C.; Rothe, S.; Stora, T.; Wendt, K.

    2010-02-01

    The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step after complete characterization is the construction and installation of the radiation-hard final trap structure and its first online application.

  6. The laser ion source trap for highest isobaric selectivity in online exotic isotope production.

    PubMed

    Schwellnus, F; Blaum, K; Catherall, R; Crepieux, B; Fedosseev, V; Gottwald, T; Kluge, H-J; Marsh, B; Mattolat, C; Rothe, S; Stora, T; Wendt, K

    2010-02-01

    The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step after complete characterization is the construction and installation of the radiation-hard final trap structure and its first online application. PMID:20192370

  7. Advances in ion trap mass spectrometry: Photodissociation as a tool for structural elucidation

    SciTech Connect

    Stephenson, J.L. Jr.; Booth, M.M.; Eyler, J.R.; Yost, R.A.

    1995-12-01

    Photo-induced dissociation (PID) is the next most frequently used method (after collisional activation) for activation of Polyatomic ions in tandem mass spectrometry. The range of internal energies present after the photon absorption process are much narrower than those obtained with collisional energy transfer. Therefore, the usefulness of PID for the study of ion structures is greatly enhanced. The long storage times and instrumental configuration of the ion trap mass spectrometer are ideally suited for photodissociation experiments. This presentation will focus on both the fundamental and analytical applications of CO{sub 2} lasers in conjunction with ion trap mass spectrometry. The first portion of this talk will examine the fundamental issues of wavelength dependence, chemical kinetics, photoabsorption cross section, and collisional effects on photodissociation efficiency. The second half of this presentation will look at novel instrumentation for electrospray/ion trap mass spectrometry, with the concurrent development of photodissociation as a tool for structural elucidation of organic compounds and antibiotics.

  8. Effects of trapped electrons on the oblique propagation of ion acoustic solitary waves in electron-positron-ion plasmas

    NASA Astrophysics Data System (ADS)

    Hafez, M. G.; Roy, N. C.; Talukder, M. R.; Hossain Ali, M.

    2016-08-01

    The characteristics of the nonlinear oblique propagation of ion acoustic solitary waves in unmagnetized plasmas consisting of Boltzmann positrons, trapped electrons and ions are investigated. The modified Kadomtsev-Petviashivili ( m K P ) equation is derived employing the reductive perturbation technique. The parametric effects on phase velocity, Sagdeev potential, amplitude and width of solitons, and electrostatic ion acoustic solitary structures are graphically presented with the relevant physical explanations. This study may be useful for the better understanding of physical phenomena concerned in plasmas in which the effects of trapped electrons control the dynamics of wave.

  9. Excitation of internal kink modes by trapped energetic beam ions

    SciTech Connect

    Chen, L.; White, R.B.; Rosenbluth, M.N.

    1983-10-01

    Energetic trapped particles are shown to have a destabilizing effect on the internal kink mode in tokamaks. The plasma pressure threshold for the mode is lowered by the particles. The growth rate is near the ideal magnetohydrodynamic value, but the frequency is comparable to the trapped particle precission frequency. A model for the instability cycle gives stability properties, associated particle losses, and neutron emissivity consistent with the fishbone events observed in PDX.

  10. Multiple mass analysis using an ion trap array (ITA) mass analyzer.

    PubMed

    Yu, Xiao; Chu, Yanqiu; Ling, Xing; Ding, Zhengzhi; Xu, Chongsheng; Ding, Li; Ding, Chuan-Fan

    2013-09-01

    A novel ion trap array (ITA) mass analyzer with six ion trapping and analyzing channels was investigated. It is capable of analyzing multiple samples simultaneously. The ITA was built with several planar electrodes made of stainless steel and 12 identical parallel zirconia ceramic substrates plated with conductive metal layers. Each two of the opposing ceramic electrode plates formed a boundary of an ion trap channel and six identical ion trapping and analyzing channels were placed in parallel without physical electrode between any two adjacent channels. The electric field distribution inside each channel was studied with simulation. The new design took the advantage of high precision machining attributable to the rigidity of ceramic, and the convenience of surface patterning technique. The ITA system was tested by using a two-channel electrospray ionization source, a multichannel simultaneous quadruple ion guide, and two detectors. The simultaneous analysis of two different samples with two adjacent ITA channels was achieved and independent mass spectra were obtained. For each channel, the mass resolution was tested. Additional ion trap functions such as mass-selected ion isolation and collision-induced dissociation (CID) were also tested. The results show that one ITA is well suited for multiple simultaneous mass analyses. PMID:23797864

  11. Multiple Mass Analysis Using an Ion Trap Array (ITA) Mass Analyzer

    NASA Astrophysics Data System (ADS)

    Xiao, Yu; Chu, Yanqiu; Ling, Xing; Ding, Zhengzhi; Xu, Chongsheng; Ding, Li; Ding, Chuan-Fan

    2013-09-01

    A novel ion trap array (ITA) mass analyzer with six ion trapping and analyzing channels was investigated. It is capable of analyzing multiple samples simultaneously. The ITA was built with several planar electrodes made of stainless steel and 12 identical parallel zirconia ceramic substrates plated with conductive metal layers. Each two of the opposing ceramic electrode plates formed a boundary of an ion trap channel and six identical ion trapping and analyzing channels were placed in parallel without physical electrode between any two adjacent channels. The electric field distribution inside each channel was studied with simulation. The new design took the advantage of high precision machining attributable to the rigidity of ceramic, and the convenience of surface patterning technique. The ITA system was tested by using a two-channel electrospray ionization source, a multichannel simultaneous quadruple ion guide, and two detectors. The simultaneous analysis of two different samples with two adjacent ITA channels was achieved and independent mass spectra were obtained. For each channel, the mass resolution was tested. Additional ion trap functions such as mass-selected ion isolation and collision-induced dissociation (CID) were also tested. The results show that one ITA is well suited for multiple simultaneous mass analyses.

  12. Computer Modeling of an Ion Trap Mass Analyzer, Part I: Low Pressure Regime.

    PubMed

    Nikolić, Dragan; Madzunkov, Stojan M; Darrach, Murray R

    2015-12-01

    We present the multi-particle simulation program suite Computational Ion Trap Analyzer (CITA) designed to calculate the ion trajectories within a Paul quadrupole ion trap developed by the Jet Propulsion Laboratory (JPL). CITA uses an analytical expression of the electrodynamic field, employing up to six terms in multipole expansion and a modified velocity-Verlet method to numerically calculate ion trajectories. The computer code is multithreaded and designed to run on shared-memory architectures. CITA yields near real-time simulations with full propagation of 26 particles per second per core. As a consequence, a realistic numbers of trapped ions (100+ million) can be used and their trajectories modeled, yielding a representative prediction of mass spectrometer analysis of trace gas species. When the model is compared with experimental results conducted at low pressures using the conventional quadrupole and dipole excitation modes, there is an excellent agreement with the observed peak shapes. Owing to the program's efficiency, CITA has been used to explore regions of trapping stability that are of interest to experimental research. These results are expected to facilitate a fast and reliable modeling of ion dynamics in miniature quadrupole ion trap and improve the interpretation of observed mass spectra. Graphical Abstract ᅟ. PMID:26286456

  13. Computer Modeling of an Ion Trap Mass Analyzer, Part I: Low Pressure Regime

    NASA Astrophysics Data System (ADS)

    Nikolić, Dragan; Madzunkov, Stojan M.; Darrach, Murray R.

    2015-12-01

    We present the multi-particle simulation program suite Computational Ion Trap Analyzer (CITA) designed to calculate the ion trajectories within a Paul quadrupole ion trap developed by the Jet Propulsion Laboratory (JPL). CITA uses an analytical expression of the electrodynamic field, employing up to six terms in multipole expansion and a modified velocity-Verlet method to numerically calculate ion trajectories. The computer code is multithreaded and designed to run on shared-memory architectures. CITA yields near real-time simulations with full propagation of 26 particles per second per core. As a consequence, a realistic numbers of trapped ions (100+ million) can be used and their trajectories modeled, yielding a representative prediction of mass spectrometer analysis of trace gas species. When the model is compared with experimental results conducted at low pressures using the conventional quadrupole and dipole excitation modes, there is an excellent agreement with the observed peak shapes. Owing to the program's efficiency, CITA has been used to explore regions of trapping stability that are of interest to experimental research. These results are expected to facilitate a fast and reliable modeling of ion dynamics in miniature quadrupole ion trap and improve the interpretation of observed mass spectra.

  14. Preparation of cold ions in strong magnetic field and its application to gas-phase NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Fuke, K.; Ohshima, Y.; Tona, M.

    2015-11-01

    Nuclear Magnetic Resonance (NMR) technique is widely used as a powerful tool to study the physical and chemical properties of materials. However, this technique is limited to the materials in condensed phases. To extend this technique to the gas-phase molecular ions, we are developing a gas-phase NMR apparatus. In this note, we describe the basic principle of the NMR detection for molecular ions in the gas phase based on a Stern-Gerlach type experiment in a Penning trap and outline the apparatus under development. We also present the experimental procedures and the results on the formation and the manipulation of cold ions under a strong magnetic field, which are the key techniques to detect the NMR by the present method.

  15. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers.

    PubMed

    Snyder, Dalton T; Pulliam, Christopher J; Wiley, Joshua S; Duncan, Jason; Cooks, R Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection. Graphical Abstract ᅟ. PMID:27032650

  16. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Snyder, Dalton T.; Pulliam, Christopher J.; Wiley, Joshua S.; Duncan, Jason; Cooks, R. Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection.

  17. Advanced Quadrupole Ion Trap Instrumentation for Low Level Vehicle Emissions Measurements

    SciTech Connect

    McLuckey, S.A.

    1997-01-01

    Quadrupole ion trap mass spectrometry has been evaluated for its potential use in vehicle emissions measurements in vehicle test facilities as an analyzer for the top 15 compounds contributing to smog generation. A variety of ionization methods were explored including ion trap in situ chemical ionization, atmospheric sampling glow discharge ionization, and nitric oxide chemical ionization in a glow discharge ionization source coupled with anion trap mass spectrometer. Emphasis was placed on the determination of hydrocarbons and oxygenated hydrocarbons at parts per million to parts per billion levels. Ion trap in situ water chemical ionization and atmospheric sampling glow discharge ionization were both shown to be amendable to the analysis of arenes, alcohols, aldehydes and, to some degree, alkenes. Atmospheric sampling glow discharge also generated molecular ions of methy-t-butyl ether (MTBE). Neither of these ionization methods, however, were found to generate diagnostic ions for the alkanes. Nitric oxide chemical ionization, on the other hand, was found to yield diagnostic ions for alkanes, alkenes, arenes, alcohols, aldehydes, and MTBE. The ability to measure a variety of hydrocarbons present at roughly 15 parts per billion at measurement rates of 3 Hz was demonstrated. All of the ions with potential to serve as parent ions in a tandem mass spectrometry experiment were found to yield parent-to-product conversion efficiencies greater than 75%. The flexibility afforded to the ion trap by use of tailored wave-forms applied to the end-caps allows parallel monitoring schemes to be devised that provide many of the advantages of tandem mass spectrometry without major loss in measurement rate. A large loss in measurement rate would ordinarily result from the use of conventional tandem mass spectrometry experiments carried out in series for a large number of targeted components. These results have demonstrated that the ion trap has an excellent combination of

  18. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers.

    PubMed

    Snyder, Dalton T; Pulliam, Christopher J; Wiley, Joshua S; Duncan, Jason; Cooks, R Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection. Graphical Abstract ᅟ.

  19. High-Fidelity Two-Qubit Gates in a Surface Ion Trap

    NASA Astrophysics Data System (ADS)

    Lobser, Daniel; Blain, Matthew; Blume-Kohout, Robin; Fortier, Kevin; Mizrahi, Jonathan; Nielsen, Erik; Rudinger, Kenneth; Sterk, Jonathan; Stick, Daniel; Maunz, Peter

    2016-05-01

    Microfabricated surface traps are capable of supporting a variety of exotic trapping geometries and provide a scalable system for trapped ion Quantum Information Processing (QIP). However, the feasibility of using surface traps for QIP has long been a point of contention because the close proximity of the ions to trap electrodes increases heating rates and might lead to laser-induced charging of the trap. As surface traps continue to evolve at a remarkable rate, their performance is rapidly approaching that of macroscopic electrode traps. Using Sandia's High-Optical-Access surface trap, we demonstrate robust single-qubit gates, both laser- and microwave-based. Our gates are accurately characterized by Gate Set Tomography (GST) and we report the first diamond norm measurements near the fault-tolerance threshold. Extending these techniques, we've realized a Mølmer-Sørensen two-qubit gate that is stable for several hours. This stability has allowed us to perform the first GST measurements of a two-qubit gate, yielding a process fidelity of 99.58(6)%. This work was supported by the Laboratory Directed Research and Development (LDRD) program at Sandia National Laboratories.

  20. Analysis of thermal radiation in ion traps for optical frequency standards

    NASA Astrophysics Data System (ADS)

    Doležal, M.; Balling, P.; Nisbet-Jones, P. B. R.; King, S. A.; Jones, J. M.; Klein, H. A.; Gill, P.; Lindvall, T.; Wallin, A. E.; Merimaa, M.; Tamm, C.; Sanner, C.; Huntemann, N.; Scharnhorst, N.; Leroux, I. D.; Schmidt, P. O.; Burgermeister, T.; Mehlstäubler, T. E.; Peik, E.

    2015-12-01

    In many of the high-precision optical frequency standards with trapped atoms or ions that are under development to date, the ac Stark shift induced by thermal radiation leads to a major contribution to the systematic uncertainty. We present an analysis of the inhomogeneous thermal environment experienced by ions in various types of ion traps. Finite element models which allow the determination of the temperature of the trap structure and the temperature of the radiation were developed for five ion trap designs, including operational traps at PTB and NPL and further optimized designs. Models were refined based on comparison with infrared camera measurement until an agreement of better than 10% of the measured temperature rise at critical test points was reached. The effective temperature rises of the radiation seen by the ion range from 0.8 K to 2.1 K at standard working conditions. The corresponding fractional frequency shift uncertainties resulting from the uncertainty in temperature are in the 10-18 range for optical clocks based on the Sr+ and Yb+ E2 transitions, and even lower for Yb+ E3, In+ and Al+. Issues critical for heating of the trap structure and its predictability were identified and design recommendations developed.

  1. Generation of a cold pulsed beam of Rb atoms by transfer from a 3D magneto-optic trap

    NASA Astrophysics Data System (ADS)

    Chanu, Sapam Ranjita; Rathod, Ketan D.; Natarajan, Vasant

    2016-08-01

    We demonstrate a technique for producing a cold pulsed beam of atoms by transferring a cloud of atoms trapped in a three dimensional magneto-optic trap (MOT). The MOT is loaded by heating a getter source of Rb atoms. We show that it is advantageous to transfer with two beams (with a small angle between them) compared to a single beam, because the atoms stop interacting with the beams in the two-beam technique, which results in a Gaussian velocity distribution. The atoms are further cooled in optical molasses by turning off the MOT magnetic field before the transfer beams are turned on.

  2. Opto-mechanical estimation of micro-trap with cold atoms via nonlinear stimulated Raman scattering spectrum

    NASA Astrophysics Data System (ADS)

    Zhang, Lin

    2013-05-01

    High-gain resonant nonlinear Raman spectrum on trapped cold atoms within a high-finesse optical cavity is simply explained under a nonlinear opto-mechanical mechanism, and a proposal using it to detect frequency of micro-trap is presented. The enhancement of this scattering spectrum is due to a coherent Raman conversion between two different cavity modes mediated by collective vibrations of atoms with nonlinear opto-mechanical couplings. The physical conditions of this technique are roughly estimated on Rubidium atoms, and a simple quantum analysis as well as a multi-body semiclassical simulation on this nonlinear Raman spectrum is conducted.

  3. Ion Trapping in the SLAC B-factory High Energy Ring

    SciTech Connect

    Villevald, D.; Heifets, S.; /SLAC

    2006-09-07

    The presence of trapped ions in electron storage rings has caused significant degradation in machine performance. The best known way to prevent the ion trapping is to leave a gap in the electron bunch train. The topic of this paper is the dynamics of ions in the field of the bunch train with uneven bunch filling. We consider High Energy Ring (HER) of the PEP-II B-factory. In the first section we summarize mechanisms of the ion production. Then the transverse and longitudinal dynamics are analyzed for a beam with and without gap. After that, the effect of the ions is considered separating all ions in the ring in several groups depending on their transverse and longitudinal stability. The main effects of the ions are the tune shift and the tune spread of the betatron oscillations of the electrons. The tune spread is produced by bunch to bunch variation of the electric field of ions and by nonlinearity of the field. It is shown that the main contribution to the shift and spread of the betatron tune of the beam is caused by two groups of ions: one-turn ions and trapped ions. One-turn ions are the ions generated during the last passage of the bunch train. Trapped ions are the ions with stable transverse and longitudinal motion. In the last section we discuss shortly related problems of parameters of the clearing electrodes, injection scenario, and collective effects. Clearing electrodes should be located at the defocusing in x-plane quadrupole magnets. An electric DC field of value 1.0 kv/cm will be enough to prevent the ion trapping process. During the injection, it is recommended to fill the bucket with the design number of the particles per bunch N{sub B} before going to the next bucket. In addition, it is recommended to have the sequential filling of the ring, i.e. the filling from one bucket to the next sequentially. It was shown that ions will not be trapped at the location of the interaction point. The reason for this is that the current of the positron beam is

  4. Highly charged ion research at the Livermore electron beam ion traps

    SciTech Connect

    Beiersdorfer, P

    2004-01-04

    Spectroscopy performed with the three Livermore electron beam ion traps is reviewed, which is continuing and complementing the innumerable contributions to atomic physics provided over the years by heavy-ion accelerators. Numerous spectrometers were developed that cover the spectral bands from the visible to the hard x ray region. These enabled exhaustive line surveys useful for x-ray astrophysics and for systematic studies along iso-electronic sequences, such as the 4s-4p, 3s-3p, and 2s-2p transitions in ions of the Cu-I, Na-I, and Li-I sequences useful for studying QED and correlation effects as well as for precise determinations of atomic-nuclear interactions. They also enabled measurements of radiative transition probabilities of very long-lived (milli- and microseconds) and very short-live (femtosecond) levels. Because line excitation processes can be controlled by choice of the electron beam energy, the observed line intensities are used to infer cross sections for electron-impact excitation, dielectronic recombination, resonance excitation, and innershell ionization. These capabilities have recently been expanded to simulate x-ray emission from comets by charge exchange. Specific contributions to basic atomic physics, nuclear physics, and high-temperature diagnostics are illustrated.

  5. Multisectional linear ion trap and novel loading method for optical spectroscopy of electron and nuclear transitions.

    PubMed

    Sysoev, Alexey A; Troyan, Victor I; Borisyuk, Peter V; Krasavin, Andrey V; Vasiliev, Oleg S; Palchikov, Vitaly G; Avdeev, Ivan A; Chernyshev, Denis M; Poteshin, Sergey S

    2015-01-01

    There is a growing need for the development of atomic and nuclear frequency standards because of the important contribution of methods for precision time and frequency measurements to the development of fundamental science, technology, and the economy. It is also conditioned by their potential use in optical clocks and quantum logic applications. It is especially important to develop a universal method that could allow one to use ions of most elements effectively (including ones that are not easily evaporated) proposed for the above-mentioned applications. A linear quadrupole ion trap for the optical spectroscopy of electron and nuclear transitions has been developed and evaluated experimentally. An ion source construction is based on an ultra-high vacuum evaporator in which a metal sample is subjected to an electron beam of energy up to 1 keV, resulting in the appearance of gaseous atoms and ions of various charge state. The linear ion trap consists of five successive quadrupole sections including an entrance quadrupole section, quadrupole mass filter, quadrupole ion guide, ion-trap section, and exit quadrupole section. The same radiofrequency but a different direct current voltage feeds the quadrupole sections. The instrument allows the mass and energy selected trapping of ions from ion beams of various intensities and their localization in the area of laser irradiation. The preliminary results presented show that the proposed instrument and methods allow one to produce effectively up to triply charged thorium ions as well as to trap ions for future spectroscopic study. The instrument is proposed for future use in optical clocks and quantum logic application development. PMID:25906029

  6. Multisectional linear ion trap and novel loading method for optical spectroscopy of electron and nuclear transitions.

    PubMed

    Sysoev, Alexey A; Troyan, Victor I; Borisyuk, Peter V; Krasavin, Andrey V; Vasiliev, Oleg S; Palchikov, Vitaly G; Avdeev, Ivan A; Chernyshev, Denis M; Poteshin, Sergey S

    2015-01-01

    There is a growing need for the development of atomic and nuclear frequency standards because of the important contribution of methods for precision time and frequency measurements to the development of fundamental science, technology, and the economy. It is also conditioned by their potential use in optical clocks and quantum logic applications. It is especially important to develop a universal method that could allow one to use ions of most elements effectively (including ones that are not easily evaporated) proposed for the above-mentioned applications. A linear quadrupole ion trap for the optical spectroscopy of electron and nuclear transitions has been developed and evaluated experimentally. An ion source construction is based on an ultra-high vacuum evaporator in which a metal sample is subjected to an electron beam of energy up to 1 keV, resulting in the appearance of gaseous atoms and ions of various charge state. The linear ion trap consists of five successive quadrupole sections including an entrance quadrupole section, quadrupole mass filter, quadrupole ion guide, ion-trap section, and exit quadrupole section. The same radiofrequency but a different direct current voltage feeds the quadrupole sections. The instrument allows the mass and energy selected trapping of ions from ion beams of various intensities and their localization in the area of laser irradiation. The preliminary results presented show that the proposed instrument and methods allow one to produce effectively up to triply charged thorium ions as well as to trap ions for future spectroscopic study. The instrument is proposed for future use in optical clocks and quantum logic application development.

  7. Quantum information experiments with 2D arrays of hundreds of trapped ions

    NASA Astrophysics Data System (ADS)

    Gilmore, Kevin; Bohnet, Justin; Sawyer, Brian; Britton, Joseph; Wall, Michael; Foss-Feig, Michael; Rey, Ana Maria; Bollinger, John

    2016-05-01

    We summarize recent experimental work with 2D arrays of hundreds of trapped 9 Be+ ions stored in a Penning trap. Penning traps utilize static magnetic and electric fields to confine ions, and enable the trapping and laser cooling of ion crystals larger than typically possible in RF ion traps. We work with single-plane ion crystals where the ions form a triangular lattice through minimization of their Coulomb potential energy. The crystals rotate, and we present numerical studies that determine optimal operating parameters for producing low temperature, stable 2-dimensional crystals with Doppler laser cooling and a rotating wall potential. Our qubit is the electron spin-flip transition in the ground state of 9 Be+ and is sensitive to magnetic field fluctuations. Through mitigation of part-per-billion, vibration-induced magnetic field fluctuations we demonstrate T2 coherence times longer than 50 ms. We engineer long-range Ising interactions with spin-dependent optical dipole forces, and summarize recent measurements that characterize the entanglement generated through single-axis twisting. Supported by: JILA-NSF-PFC-1125844, NSF-PHY-1521080, ARO, AFOSR, AFOSR-MURI.

  8. Precision Experiments with Single Particles in Ion Traps for Tests of Fundamental Interactions

    NASA Astrophysics Data System (ADS)

    Quint, Wolfgang

    2007-06-01

    Ion trap technology has made it possible to store, cool and observe single ions or ensembles of few ions under well controlled experimental conditions and at very low temperatures [1]. Single particles in traps allow for clean investigations of basic interactions and also for the determination of fundamental constants. This has been demonstrated by investigations of Quantum Electrodynamics (QED) with respect to the g-factor of the free electron [2] and of the electron bound in hydrogen-like carbon and oxygen [3], which form the most precise determinations of the fine-structure constant and of the mass of the electron, respectively. A precision test of CPT invariance has been performed in a proton-antiproton mass comparison with single particles in a Penning trap [4]. Optical quantum jump spectroscopy with single laser-cooled ions in rf traps has paved the way for optical frequency standards and for the investigation of a possible variation of fundamental constants. With the novel technique of deceleration, trapping and cooling, even high-accuracy experiments with highly charged ions up to uranium U91+ will be possible at the HITRAP facility at GSI Darmstadt [5]. [1] Observation of a Phase Transition of Stored Laser-Cooled Ions, F. Diedrich, E. Peik, J.M. Chen, W. Quint, H. Walther, Phys. Rev. Lett. 59, 2931 (1987) [2] New Determination of the Fine Structure Constant from the Electron g Value and QED, G. Gabrielse et al., Phys. Rev. Lett. 97, 030802 (2006). [3] New Determination of the Electron's Mass, T. Beier et al., Phys. Rev. Lett. 88, 011603 (2002). [4] Precision Mass Spectroscopy of the Antiproton and Proton Using Simultaneously Trapped Particles, G. Gabrielse et al., Phys. Rev. Lett. 82, 3198 (1999). [5] Trapping ions of hydrogen-like uranium: The HITRAP project at GSI, T. Beier et al., NIM B 235, 473 (2005).

  9. An electrodynamic ion funnel interface for greater sensitivity and higher throughput with linear ion trap mass spectrometers

    SciTech Connect

    Page, Jason S.; Tang, Keqi; Smith, Richard D.

    2007-09-01

    An electrospray ionization interface incorporating an electrodynamic ion funnel has been designed and implemented in conjunction with a linear ion trap mass spectrometer (Thermo Electron, LTQ). We found ion transmission to be greatly improved by replacing the standard capillary-skimmer interface with the capillary-ion funnel interface. An infusion study using a serial dilution of a reserpine solution showed that ion injection times to fill the ion trap were reduced by ~90% which resulted in an ~10-fold increase in reported peak intensities. In liquid chromatography (LC)-MS and LC tandem MS (MS/MS) experiments performed using a proteomic sample from the bacterium, Shewanella oneidensis, the ion funnel interface provided an ~7-fold reduction in ion injection (accumulation) times. In a series of LC-MS/MS experiments we found that more dilute S. oneidensis samples provided more peptide and protein identifications when the ion funnel interface was used in place of the standard interface. This improvement was most pronounced at lower sample concentrations, where extended ion accumulation times are required, resulting in an ~2-fold increase in the number of protein identifications. Implementation of the ion funnel interface with a LTQ Fourier transform (FT) MS requiring much greater ion populations resulted in spectrum acquisition times reduced by ~25 to 50%.

  10. High resolution extreme ultraviolet spectrometer for an electron beam ion trap

    SciTech Connect

    Ohashi, Hayato; Yatsurugi, Junji; Nakamura, Nobuyuki; Sakaue, Hiroyuki A.

    2011-08-15

    An extreme ultraviolet spectrometer has been developed for spectroscopic studies of highly charged ions with an electron beam ion trap. It has a slit-less configuration with a spherical varied-line-spacing grating that provides a flat focal plane for grazing incidence light. Alternative use of two different gratings enables us to cover the wavelength range 1-25 nm. Test observations with the Tokyo electron beam ion trap demonstrate the high performance of the present spectrometer such as a resolving power of above 1000.

  11. Effects of trapped electrons on ion reflection in an oblique shock wave

    SciTech Connect

    Toida, Mieko; Inagaki, Junya

    2015-06-15

    A magnetosonic shock wave propagating obliquely to an external magnetic field can trap electrons and accelerate them to ultrarelativistic energies. The trapped electrons excite two-dimensional (2D) electromagnetic fluctuations with finite wavenumbers along the shock front. We study effects of the trapped electrons on ion motions through the 2D fluctuations. It is analytically shown that the fraction of ions reflected from the shock front is enhanced by the 2D fluctuations. This is confirmed by 2D (two space coordinates and three velocities) relativistic, electromagnetic particle simulations with full ion and electron dynamics and calculation of test ions in the electromagnetic fields averaged along the shock front. A comparison between 2D and one-dimensional electromagnetic particle simulations is also shown.

  12. Finite-geometry models of electric field noise from patch potentials in ion traps

    SciTech Connect

    Low, Guang Hao; Herskind, Peter F.; Chuang, Isaac L.

    2011-11-15

    We model electric field noise from fluctuating patch potentials on conducting surfaces by taking into account the finite geometry of the ion trap electrodes to gain insight into the origin of anomalous heating in ion traps. The scaling of anomalous heating rates with surface distance d is obtained for several generic geometries of relevance to current ion trap designs, ranging from planar to spheroidal electrodes. The influence of patch size is studied both by solving Laplace's equation in terms of the appropriate Green's function as well as through an eigenfunction expansion. Scaling with surface distance is found to be highly dependent on the choice of geometry and the relative scale between the spatial extent of the electrode, the ion-electrode distance, and the patch size. Our model generally supports the d{sup -4} dependence currently found by most experiments and models, but also predicts geometry-driven deviations from this trend.

  13. Phase-Stable Free-Space Optical Lattices for Trapped Ions.

    PubMed

    Schmiegelow, C T; Kaufmann, H; Ruster, T; Schulz, J; Kaushal, V; Hettrich, M; Schmidt-Kaler, F; Poschinger, U G

    2016-01-22

    We demonstrate control of the absolute phase of an optical lattice with respect to a single trapped ion. The lattice is generated by off-resonant free-space laser beams, and we actively stabilize its phase by measuring its ac-Stark shift on a trapped ion. The ion is localized within the standing wave to better than 2% of its period. The locked lattice allows us to apply displacement operations via resonant optical forces with a controlled direction in phase space. Moreover, we observe the lattice-induced phase evolution of spin superposition states in order to analyze the relevant decoherence mechanisms. Finally, we employ lattice-induced phase shifts for inferring the variation of the ion position over the 157  μm range along the trap axis at accuracies of better than 6 nm.

  14. Paul trapping of radioactive 6He+ ions and direct observation of their beta decay.

    PubMed

    Fléchard, X; Liénard, E; Méry, A; Rodríguez, D; Ban, G; Durand, D; Duval, F; Herbane, M; Labalme, M; Mauger, F; Naviliat-Cuncic, O; Thomas, J C; Velten, Ph

    2008-11-21

    We demonstrate that abundant quantities of short-lived beta unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6He+ (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 6Li++ recoiling ions have been recorded. The technique can be extended to other short-lived species, opening new possibilities for trap assisted decay experiments.

  15. Universal nonmonotonic structure in the saturation curves of magneto-optical-trap-loaded Na+ ions stored in an ion-neutral hybrid trap: Prediction and observation

    NASA Astrophysics Data System (ADS)

    Blümel, R.; Wells, J. E.; Goodman, D. S.; Kwolek, J. M.; Smith, W. W.

    2015-12-01

    We predict that the maximal, steady-state ion capacity Ns(λ ) of radio-frequency (rf) traps, loaded at a rate of λ particles per rf cycle, shows universal, nonlinear, nonmonotonic behavior as a function of loading rate λ . The shape of Ns(λ ) , characterized by four dynamical regimes, is universal; i.e., it is predicted to manifest itself in all types of rf traps independent of the details of their construction and independent of particle species loaded. For λ ≪ 1 (region I), as expected, Ns(λ ) increases monotonically with λ . However, contrary to intuition, at intermediate λ ˜1 (region II), Ns(λ ) reaches a maximum, followed by a local minimum of Ns(λ ) (region III). For λ ≫1 (region IV), Ns(λ ) again rises monotonically. In region IV, numerical simulations, analytical calculations, and experiments show Ns(λ ) ˜λ2 /3 . We confirm our predictions both experimentally with magneto-optical-trap-loaded Na+ ions stored in a hybrid ion-neutral trap and numerically with the help of detailed ab initio molecular-dynamics simulations.

  16. Microfabricated ion trap mass spectrometry for characterization of organics and potential biomarkers

    NASA Astrophysics Data System (ADS)

    Austin, Daniel

    Mass spectrometry is a powerful analytical technique with a strong history in planetary exploration, and is the method of choice for detection and identification of organic and biological molecules. MS instrumentation can also be combined with techniques such as gas chromatography, liquid chromatography, or chiral separation, which are particularly important for analysis of complex mixtures or possible homochirality. Ion traps have several inherent advantages, including speed of analysis (important for GC-MS), MS/MS capabilities (important to identification of unknown compounds), excellent sensitivity, and ease of coupling with ambient ionization techniques that are under development for biomolecule detection. We report on progress in using microfabrication techniques to produce radiofrequency quadrupole ion traps that are much smaller, lighter, and lower power than existing instruments. We produce ion traps using an assembly of two ceramic plates, the facing surfaces of which are lithographically patterned with electrodes. This approach allows great flexibility in the trap geometry, and we have demonstrated working mass spectrometers with quadrupole, linear, and toroidal trapping fields. The approach also allows correction of higher-order terms in the electric field. With this system, mass resolution of up to 1300 has been demonstrated, which is adequate for identification of a wide range of potential biomarkers. Capabilities such as tandem analysis have also been demonstrated. Of particular interest is an ion trap that contains both quadrupole and toroidal trapping regions simultaneously and coaxially. Ions can be trapped as a large reservoir in the toroidal region and introduced in small batches to the quadrupole region for mass analysis. This capability is particularly valuable where the sample of interest is very small, such as microfossil with trace organics, and where the organic inventory is both complex and unknown. Development and results of this device

  17. Final Report - Advanced Ion Trap Mass Spectrometry Program - Oak Ridge National Laboratory - Sandia National Laboratory

    SciTech Connect

    Whitten, W.B.

    2002-12-18

    This report covers the three main projects that collectively comprised the Advanced Ion Trap Mass Spectrometry Program. Chapter 1 describes the direct interrogation of individual particles by laser desorption within the ion trap mass spectrometer analyzer. The goals were (1) to develop an ''intelligent trigger'' capable of distinguishing particles of biological origin from those of nonbiological origin in the background and interferent particles and (2) to explore the capability for individual particle identification. Direct interrogation of particles by laser ablation and ion trap mass spectrometry was shown to have good promise for discriminating between particles of biological origin and those of nonbiological origin, although detailed protocols and operating conditions were not worked out. A library of more than 20,000 spectra of various types of biological particles has been assembled. Methods based on multivariate analysis and on neural networks were used to discriminate between particles of biological origin and those of nonbiological origin. It was possible to discriminate between at least some species of bacteria if mass spectra of several hundred similar particles were obtained. Chapter 2 addresses the development of a new ion trap mass analyzer geometry that offers the potential for a significant increase in ion storage capacity for a given set of analyzer operating conditions. This geometry may lead to the development of smaller, lower-power field-portable ion trap mass spectrometers while retaining laboratory-scale analytical performance. A novel ion trap mass spectrometer based on toroidal ion storage geometry has been developed. The analyzer geometry is based on the edge rotation of a quadrupolar ion trap cross section into the shape of a torus. Initial performance of this device was poor, however, due to the significant contribution of nonlinear fields introduced by the rotation of the symmetric ion-trapping geometry. These nonlinear resonances

  18. Cold ion UV photofragmentation spectroscopy and dynamics (Invited)

    NASA Astrophysics Data System (ADS)

    Feraud, Geraldine; Broquier, Michel; Dedonder, Claude; Jouvet, Christophe; Gregoire, Gilles; Soorkia, Satchin

    2014-12-01

    Up to ten years ago, very little was known about the excited states of protonated amino acids isolated in the gas phase. From the experimental point of view, the study was hampered by the lack of ease of production of such species in sufficient density to apply photon-based techniques. With the development and widespread use of electrospray ionization sources coupled with modified or homebuilt mass spectrometers, there has been significant research into the spectroscopy of biomimetic and biologically relevant molecules. Besides, these species are floppy such that an efficient cooling is required to record clear spectroscopy. Warm protonated species display congested spectra. To extract precise spectroscopic information and avoid spectral congestion, the species need to be cooled down to less than 50 K. We present our latest results on the electronic spectroscopy of protonated phenylalanine and tyrosine on a large spectral domain (225-290 nm). These species are studied in a new simplified apparatus combining an electrospray ionization source, a cryogenically cooled quadrupole ion trap (˜10 K) and time-of-flight mass spectrometry. The role of proton transfer from the NH3+ moiety to the p-ring or to CO of the carboxylic acid group is evidenced by UV photofragment spectroscopy. This first step controls the fragmentation pathways, which strongly depend on the nature of the electronic excited states, i.e. ππ*, ππ*CO and πσNH 3.

  19. Cold ion UV photofragmentation spectroscopy and dynamics (Invited)

    SciTech Connect

    Feraud, Geraldine; Dedonder, Claude; Jouvet, Christophe; Broquier, Michel; Gregoire, Gilles; Soorkia, Satchin

    2014-12-09

    Up to ten years ago, very little was known about the excited states of protonated amino acids isolated in the gas phase. From the experimental point of view, the study was hampered by the lack of ease of production of such species in sufficient density to apply photon-based techniques. With the development and widespread use of electrospray ionization sources coupled with modified or homebuilt mass spectrometers, there has been significant research into the spectroscopy of biomimetic and biologically relevant molecules. Besides, these species are floppy such that an efficient cooling is required to record clear spectroscopy. Warm protonated species display congested spectra. To extract precise spectroscopic information and avoid spectral congestion, the species need to be cooled down to less than 50 K. We present our latest results on the electronic spectroscopy of protonated phenylalanine and tyrosine on a large spectral domain (225-290 nm). These species are studied in a new simplified apparatus combining an electrospray ionization source, a cryogenically cooled quadrupole ion trap (∼10 K) and time-of-flight mass spectrometry. The role of proton transfer from the NH{sub 3}{sup +} moiety to the p-ring or to CO of the carboxylic acid group is evidenced by UV photofragment spectroscopy. This first step controls the fragmentation pathways, which strongly depend on the nature of the electronic excited states, i.e. ππ*, ππ*{sub CO} and πσ{sub NH3}.

  20. Experimental quantum simulations of many-body physics with trapped ions.

    PubMed

    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.

  1. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    SciTech Connect

    Schneider, D.

    1995-10-01

    The experimental groups in the Electron Beam Ion Trap (EBIT) program continue to perform front-line research with trapped and extracted highly charged ions (HCI) in the areas of ion/surface interactions, atomic spectroscopy, electron-ion interaction and structure measurements, highly charged ion confinement, and EBIT development studies. The ion surface/interaction studies which were initiated five years ago have reached a stage where they an carry out routine investigations, as well as produce breakthrough results towards the development of novel nanotechnology. At EBIT and SuperEBIT studies of the x-ray emission from trapped ions continue to produce significant atomic structure data with high precision for few electron systems of high-Z ions. Furthermore, diagnostics development for magnetic and laser fusion, supporting research for the x-ray laser and weapons programs, and laboratory astrophysics experiments in support of NASA`s astrophysics program are a continuing effort. The two-electron contributions to the binding energy of helium like ions were measured for the first time. The results are significant because their precision is an order of magnitude better than those of competing measurements at accelerators, and the novel technique isolates the energy corrections that are the most interesting. The RETRAP project which was initiated three years ago has reached a stage where trapping, confining and electronic cooling of HCI ions up to Th{sup 80+} can be performed routinely. Measurements of the rates and cross sections for electron transfer from H{sub 2} performed to determine the lifetime of HCI up to Xe{sup q+} and Th{sup q+} (35 {le} q {le} 80) have been studied at mean energies estimated to be {approximately} 5 q eV. This combination of heavy ions with very high charges and very low energies is rare in nature, but may be encountered in planned fusion energy demonstration devices, in highly charged ion sources, or in certain astrophysical events.

  2. Power-law distributions for a trapped ion interacting with a classical buffer gas.

    PubMed

    DeVoe, Ralph G

    2009-02-13

    Classical collisions with an ideal gas generate non-Maxwellian distribution functions for a single ion in a radio frequency ion trap. The distributions have power-law tails whose exponent depends on the ratio of buffer gas to ion mass. This provides a statistical explanation for the previously observed transition from cooling to heating. Monte Carlo results approximate a Tsallis distribution over a wide range of parameters and have ab initio agreement with experiment. PMID:19257583

  3. Self-generated zonal flows in the plasma turbulence driven by trapped-ion and trapped-electron instabilities

    SciTech Connect

    Drouot, T.; Gravier, E.; Reveille, T.; Collard, M.

    2015-10-15

    This paper presents a study of zonal flows generated by trapped-electron mode and trapped-ion mode micro turbulence as a function of two plasma parameters—banana width and electron temperature. For this purpose, a gyrokinetic code considering only trapped particles is used. First, an analytical equation giving the predicted level of zonal flows is derived from the quasi-neutrality equation of our model, as a function of the density fluctuation levels and the banana widths. Then, the influence of the banana width on the number of zonal flows occurring in the system is studied using the gyrokinetic code. Finally, the impact of the temperature ratio T{sub e}/T{sub i} on the reduction of zonal flows is shown and a close link is highlighted between reduction and different gyro-and-bounce-average ion and electron density fluctuation levels. This reduction is found to be due to the amplitudes of gyro-and-bounce-average density perturbations n{sub e} and n{sub i} gradually becoming closer, which is in agreement with the analytical results given by the quasi-neutrality equation.

  4. Self-generated zonal flows in the plasma turbulence driven by trapped-ion and trapped-electron instabilities

    NASA Astrophysics Data System (ADS)

    Drouot, T.; Gravier, E.; Reveille, T.; Collard, M.

    2015-10-01

    This paper presents a study of zonal flows generated by trapped-electron mode and trapped-ion mode micro turbulence as a function of two plasma parameters—banana width and electron temperature. For this purpose, a gyrokinetic code considering only trapped particles is used. First, an analytical equation giving the predicted level of zonal flows is derived from the quasi-neutrality equation of our model, as a function of the density fluctuation levels and the banana widths. Then, the influence of the banana width on the number of zonal flows occurring in the system is studied using the gyrokinetic code. Finally, the impact of the temperature ratio Te/Ti on the reduction of zonal flows is shown and a close link is highlighted between reduction and different gyro-and-bounce-average ion and electron density fluctuation levels. This reduction is found to be due to the amplitudes of gyro-and-bounce-average density perturbations ne and ni gradually becoming closer, which is in agreement with the analytical results given by the quasi-neutrality equation.

  5. Optimizing the Stark-decelerator beamline for the trapping of cold molecules using evolutionary strategies

    SciTech Connect

    Gilijamse, Joop J.; Kuepper, Jochen; Hoekstra, Steven; Vanhaecke, Nicolas; Meerakker, Sebastiaan Y. T. van de; Meijer, Gerard

    2006-06-15

    We demonstrate feedback control optimization for the Stark deceleration and trapping of neutral polar molecules using evolutionary strategies. In a Stark-decelerator beamline, pulsed electric fields are used to decelerate OH radicals and subsequently store them in an electrostatic trap. The efficiency of the deceleration and trapping process is determined by the exact timings of the applied electric field pulses. Automated optimization of these timings yields an increase of 40% of the number of trapped OH radicals.

  6. Assembling a ring-shaped crystal in a microfabricated surface ion trap

    SciTech Connect

    Stick, Daniel Lynn; Tabakov, Boyan; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; Sterk, Jonathan D.; Tigges, Chris

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

  7. Mass determination of light ions in a Penning trap by time-of-flight detection of ion resonances

    NASA Astrophysics Data System (ADS)

    Kern, J.; Engel, T.; Hagena, D.; Werth, G.

    1992-12-01

    We describe an experimental setup to determine the cyclotron frequencies of ions confined in a Penning trap by resonant excitation of the ions eigenfrequencies and a time-of-flight detection of the resonances. Systematic shifts from trap- and B-field imperfections are discussed and methods to minimize those effects in our experiment are presented. Results on the mass ratio for 4He/D2 and 3He/H2 demonstrate the experimentally obtained precision in the ppb range, which might be further improved by modification of our apparatus.

  8. Magnetic reconnection and modification of the Hall physics due to cold ions at the magnetopause

    NASA Astrophysics Data System (ADS)

    André, M.; Li, W.; Toledo-Redondo, S.; Khotyaintsev, Yu. V.; Vaivads, A.; Graham, D. B.; Norgren, C.; Burch, J.; Lindqvist, P.-A.; Marklund, G.; Ergun, R.; Torbert, R.; Magnes, W.; Russell, C. T.; Giles, B.; Moore, T. E.; Chandler, M. O.; Pollock, C.; Young, D. T.; Avanov, L. A.; Dorelli, J. C.; Gershman, D. J.; Paterson, W. R.; Lavraud, B.; Saito, Y.

    2016-07-01

    Observations by the four Magnetospheric Multiscale spacecraft are used to investigate the Hall physics of a magnetopause magnetic reconnection separatrix layer. Inside this layer of currents and strong normal electric fields, cold (eV) ions of ionospheric origin can remain frozen-in together with the electrons. The cold ions reduce the Hall current. Using a generalized Ohm's law, the electric field is balanced by the sum of the terms corresponding to the Hall current, the v × B drifting cold ions, and the divergence of the electron pressure tensor. A mixture of hot and cold ions is common at the subsolar magnetopause. A mixture of length scales caused by a mixture of ion temperatures has significant effects on the Hall physics of magnetic reconnection.

  9. Production of NaCa+ molecular ions in the ground state from cold atom-ion mixtures by photoassociation via an intermediate state

    NASA Astrophysics Data System (ADS)

    Gacesa, Marko; Montgomery, John A.; Michels, H. Harvey; Côté, Robin

    2016-07-01

    We present a theoretical analysis of optical pathways for formation of cold ground-state (NaCa) + molecular ions via an intermediate state. The formation schemes are based on ab initio potential energy curves and transition dipole moments calculated using effective-core-potential methods of quantum chemistry. In the proposed approach, starting from a mixture of cold trapped Ca+ ions immersed into an ultracold gas of Na atoms, (NaCa) + molecular ions are photoassociated in the excited E +1Σ electronic state and allowed to spontaneously decay either to the ground electronic state or an intermediate state from which the population is transferred to the ground state via an additional optical excitation. By analyzing all possible pathways, we find that the efficiency of a two-photon scheme, via either the B +1Σ or C +1Σ potential, is sufficient to produce significant quantities of ground-state (NaCa) + molecular ions. A single-step process results in lower formation rates that would require either a high-density sample or a very intense photoassociation laser to be viable.

  10. Characterization of environmental samples using ion trap-secondary ion mass spectrometry

    SciTech Connect

    Groenewold, G.S.; Appelhans, A.D.; Ingram, J.C.

    1998-02-01

    The detection of chemical warfare agent residues on environmental surfaces is an important analytical activity because of the potential for proliferation of these weapons, and for environmental monitoring in areas where they are stored. Historically, one of the most widely used agents has been bis(2-chloroethyl) sulfide, also known as mustard gas and HD. It was initially used in combat in 1917; by the end of the First World War, more than 16% of all casualties were due to chemicals, in most cases mustard. Manufacture of mustard is continuing to this day; consequently, there are ongoing opportunities for exposure. 2-Chloroethyl ethyl sulfide (CEES) is used as a simulant for mustard (HD) in a study to develop secondary ion mass spectrometry (SIMS) for rapid, semi-quantitative detection of mustard on soil. Using SIMS with single stage mass spectrometry, a signature for CEES can be unequivocally observed only at the highest concentrations (0.1 monolayer and above). Selectivity and sensitivity are markedly improved employing multiple-stage mass spectrometry using an ion trap. C{sub 2}H{sub 5}SC{sub 2}H{sub 4}{sup +} from CEES eliminates C{sub 2}H{sub 4} and H{sub 2}S, which are highly diagnostic. CEES was detected at 0.0012 monolayer on soil. A single analysis could be conducted in under 5 minutes.

  11. Infrared Multiphoton Dissociation of Peptide Cations in a Dual Pressure Linear Ion Trap Mass Spectrometer

    PubMed Central

    Gardner, Myles W.; Smith, Suncerae I.; Ledvina, Aaron R.; Madsen, James A.; Coon, Joshua J.; Schwartz, Jae C.; Stafford, George C.; Brodbelt, Jennifer S.

    2009-01-01

    A dual pressure linear ion trap mass spectrometer was modified to permit infrared multiphoton dissociation (IRMPD) in each of the two cells - the first a high pressure cell operated at nominally 5 × 10-3 Torr and the second a low pressure cell operated at nominally 3 × 10-4 Torr. When IRMPD was performed in the high pressure cell, most peptide ions did not undergo significant photodissociation; however, in the low pressure cell peptide cations were efficiently dissociated with less than 25 ms of IR irradiation regardless of charge state. IRMPD of peptide cations allowed the detection of low m/z product ions including the y1 fragments and immonium ions which are not typically observed by ion trap collision induced dissociation (CID). Photodissociation efficiencies of ~100% and MS/MS (tandem mass spectrometry) efficiencies of greater than 60% were observed for both multiply and singly protonated peptides. In general, higher sequence coverage of peptides was obtained using IRMPD over CID. Further, greater than 90% of the product ion current in the IRMPD mass spectra of doubly charged peptide ions was composed of singly charged product ions compared to the CID mass spectra in which the abundances of the multiply and singly charged product ions were equally divided. Highly charged primary product ions also underwent efficient photodissociation to yield singly charged secondary product ions, thus simplifying the IRMPD product ion mass spectra. PMID:19739654

  12. Wave packet dynamics of an atomic ion in a Paul trap

    NASA Astrophysics Data System (ADS)

    Hashemloo, A.; Dion, C. M.; Rahali, G.

    2016-07-01

    Using numerical simulations of the time-dependent Schrödinger equation, we study the full quantum dynamics of the motion of an atomic ion in a linear Paul trap. Such a trap is based on a time-varying, periodic electric field and hence corresponds to a time-dependent potential for the ion, which we model exactly. We compare the center-of-mass motion with that obtained from classical equations of motion, as well as to results based on a time-independent effective potential. We also study the oscillations of the width of the ion’s wave packet, including close to the border between stable (bounded) and unstable (unbounded) trajectories. Our results confirm that the center-of-mass motion always follows the classical trajectory, that the width of the wave packet is bounded for trapping within the stability region, and therefore that the classical trapping criterion is fully applicable to quantum motion.

  13. The measurement of cold ion densities in the plasma trough. [in magnetosphere

    NASA Technical Reports Server (NTRS)

    Harris, K. K.

    1974-01-01

    The cold ion density in the plasma trough region is an important fundamental parameter in the currently proposed mechanisms to describe magnetospheric dynamics. Direct in situ measurements of the cold ion density are generally difficult owing to uncertainties in vehicle potentials and ion temperatures. It is shown that the light ion mass spectrometer from Ogo 5 was very successful in acquiring these data and that vehicle potentials appear not to have been a prohibitive factor. The cold ion plasma trough data show a great deal of variability, indicating a strong dependence on the state of the convection electric field; consequently, average values of cold ion densities in the plasma trough may be significantly different from the actual time-dependent values. The local time plot of plasma trough densities at L = 7 for data acquired over a 1-year period shows the anticipated increase in cold ion density during the daytime and the expected decrease in cold ion density during dusk and early nighttime.

  14. An electrodynamic ion funnel interface for greater sensitivity and higher throughput with linear ion trap mass spectrometers

    NASA Astrophysics Data System (ADS)

    Page, Jason S.; Tang, Keqi; Smith, Richard D.

    2007-09-01

    An electrospray ionization interface incorporating an electrodynamic ion funnel has been designed and implemented on a linear ion trap mass spectrometer (Thermo Electron, LTQ). We found ion transmission to be greatly improved by replacing the standard capillary-skimmer interface with the capillary-ion funnel interface. An infusion study using a serial dilution of a reserpine solution showed that ion injection (accumulation) times to fill the ion trap at a given automatic gain control (AGC) target value were reduced by ~90% which resulted in an ~10-fold increase in peak intensities. In liquid chromatography tandem MS (LC-MS/MS) experiments performed using a global protein digest sample from the bacterium, Shewanella oneidensis, more peptides and proteins were identified when the ion funnel interface was used in place of the standard interface. This improvement was most pronounced at lower sample concentrations, where extended ion accumulation times are required, resulting in an ~2-fold increase in the number of protein identifications. Implementation of the ion funnel interface on a LTQ Fourier transform (FT) mass spectrometer showed a ~25-50% reduction in spectrum acquisition time. The duty cycle improvement in this case was due to the ion accumulation event contributing a larger portion to the total spectrum acquisition time.

  15. Fabrication of a planar micro Penning trap and numerical investigations of versatile ion positioning protocols

    NASA Astrophysics Data System (ADS)

    Hellwig, M.; Bautista-Salvador, A.; Singer, K.; Werth, G.; Schmidt-Kaler, F.

    2010-06-01

    We describe a versatile planar Penning trap structure, which allows one to dynamically modify the trapping configuration almost arbitrarily. The trap consists of 37 hexagonal electrodes, each with a circumcircle diameter of 300 μm, fabricated in a gold-on-sapphire lithographic technique. Every hexagon can be addressed individually, thus shaping the electric potential. The fabrication of such a device with clean room methods is demonstrated. We illustrate the variability of the device by a detailed numerical simulation of a lateral and a vertical transport and simulate trapping in racetrack and artificial crystal configurations. The trap may be used for ions or electrons, as a versatile container for quantum optics and quantum information experiments.

  16. Stored waveform inverse Fourier transform (SWIFT) ion excitation in trapped-ion mass spectometry: Theory and applications

    NASA Astrophysics Data System (ADS)

    Guan, Shenheng; Marshall, Alan G.

    1996-12-01

    Stored waveform excitation produced by inverse Fourier transformation of a specified magnitude/phase excitation spectrum offers the most general and versatile means for broadband mass-selective excitation and ejection in Penning (FT-ICR) and Paul (quadrupole) ion trap mass spectrometry. Since the last comprehensive review of SWIFT excitation in 1987, the technique has been adopted, modified, and extended widely in both the ICR and quadrupole ion trap communities. Here, we review the principles, variations, algorithms, hardware implementation, and some applications of SWIFT for both ICR and quadrupole ion trap mass spectrometry. We show that the most desirable SWIFT waveform is that optimized to reduce both the time-domain SWIFT maximum amplitude and the amplitude near the start and end of the SWIFT waveform. We examine the "true" magnitude excitation spectrum, obtained by zero-filling and forward Fourier transforming the SWIFT time-domain waveform, in order to evaluate the trade-off between spectral magnitude uniformity and frequency (mass) selectivity. Apodization of the SWIFT waveform is optimally conducted by smoothing the excitation magnitude spectrum prior to generation of the SWIFT waveform by inverse FT. When (as for broadband ejection in a quadrupole ion trap) it is important that ions be excited near-simultaneously over a wide mass range, the phase spectrum (before inverse FT to generate the SWIFT waveform) may be overmodulated or randomly modulated ("filtered noise field"), with the recognition that very substantial non-uniformity in the "true" excitation magnitude spectrum will result.

  17. Planar ion trap (retarding potential analyzer) experiment for atmosphere explorer

    NASA Technical Reports Server (NTRS)

    Hanson, W. B.; Sanatani, S.; Lippincott, C. R.; Zuccaro, D. R.

    1982-01-01

    The retarding potential analyzer and drift meter were carried aboard all three Atmosphere Explorer spacecraft. These instruments measure the total thermal ion concentration and temperature, the bulk thermal ion velocity vector and some limited properties of the relative abundance of H(+), He(+), O(+) and molecular ions. These instruments functioned with no internal failures on all the spacecraft. On AE-E there existed some evidence for external surface contamination that damaged the integrity of the RPA sweep grids. This led to some difficulties in data reduction and interpretation that did not prove to be a disastrous problem. The AE-D spacecraft functioned for only a few months before it re-entered. During this time the satellite suffered from a nutation about the spin axis of about + or - 2 deg. This 2 deg modulation was superimposed upon the ion drift meter horizontal ion arrival angle output requiring the employment of filtering techniques to retrieve the real data.

  18. Effect of microsolvation on hydrogen trapping potential of metal ions

    NASA Astrophysics Data System (ADS)

    Das, Ranjita; Bandaru, Sateesh; D'mello, Viola Caroline; Chattaraj, Pratim Kumar

    2013-03-01

    A thorough analysis is carried out to understand how the microsolvation affects the hydrogen adsorbing capacity of metal ions in the presence as well as absence of the counter ions. Calculations are done at different levels of theory by using different functionals and basis sets and also by using the BSSE correction. The Be2+ ion doped systems exhibit stronger interaction with the hydrogen molecule than the other metal doped systems. The extent of interaction is less affected by the method of computation. The reaction free energy values imply that adsorption on alkaline earth metal doped systems is spontaneous at room temperature. Interaction energies are favorable for hydrogen adsorption on the systems containing alkaline earth metal ions and the gravimetric density of adsorbed hydrogen molecule is more in those containing the alkali metal ions.

  19. Rotational dynamics of a diatomic molecular ion in a Paul trap

    SciTech Connect

    Hashemloo, A.; Dion, C. M.

    2015-11-28

    We present models for a heteronuclear diatomic molecular ion in a linear Paul trap in a rigid-rotor approximation, one purely classical and the other where the center-of-mass motion is treated classically, while rotational motion is quantized. We study the rotational dynamics and their influence on the motion of the center-of-mass, in the presence of the coupling between the permanent dipole moment of the ion and the trapping electric field. We show that the presence of the permanent dipole moment affects the trajectory of the ion and that it departs from the Mathieu equation solution found for atomic ions. For the case of quantum rotations, we also evidence the effect of the above-mentioned coupling on the rotational states of the ion.

  20. Integrated Technologies for Large-Scale Trapped-Ion Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Sorace-Agaskar, C.; Bramhavar, S.; Kharas, D.; Mehta, K. K.; Loh, W.; Panock, R.; Bruzewicz, C. D.; McConnell, R.; Ram, R. J.; Sage, J. M.; Chiaverini, J.

    2016-05-01

    Atomic ions trapped and controlled using electromagnetic fields hold great promise for practical quantum information processing due to their inherent coherence properties and controllability. However, to realize this promise, the ability to maintain and manipulate large-scale systems is required. We present progress toward the development of, and proof-of-principle demonstrations and characterization of, several technologies that can be integrated with ion-trap arrays on-chip to enable such scaling to practically useful sizes. Of particular use are integrated photonic elements for routing and focusing light throughout a chip without the need for free-space optics. The integration of CMOS electronics and photo-detectors for on-chip control and readout, and methods for monolithic fabrication and wafer-scale integration to incorporate these capabilities into tile-able 2D ion-trap array cells, are also explored.

  1. Parity-relevant zitterbewegung and quantum simulation by a single trapped ion

    SciTech Connect

    Wang Kunling; Liu Tao; Feng Mang; Yang Wanli; Wang Kelin

    2010-12-15

    Zitterbewegung (ZB), the trembling of free relativistic electrons in a vacuum, could be simulated by a single trapped ion. We focus on the variations of ZB under different parity conditions and find no ZB in the case of odd or even parity. ZB occurs only for the admixture of the odd- and even-parity states. We also show that a similar role is played by the parity operator for the trapped ion in Fock-state representation and the space-inversion operator for a realistic relativistic electron. Although the ZB effect is invisible in a relativistic electron, preparation of the trapped ion in different parity states is a sophisticated job, which makes it possible to observe the parity-relevant ZB effects with currently available techniques.

  2. Thermally activated hopping of two ions trapped in a bistable potential well

    NASA Astrophysics Data System (ADS)

    Abich, K.; Keil, A.; Reiss, D.; Wunderlich, Ch; Neuhauser, W.; Toschek, P. E.

    2004-03-01

    With two ions in a spheroidal Paul trap, the harmonic trapping potential turns, by Coulomb repulsion, into a bistable well. Two Ba ions have been confined, laser-cooled, and observed, via their laser-excited resonance scattering, by a spatially resolving photomultiplier, or intensifying CCD camera. A repump laser releases the ions from a metastable state. Well-cooled ions are found localized. When the laser is detuned, the Raman cooling rate and the ions' temperature vary. A transition from the crystallized state to a toroidal gas takes place. The ions are discriminated when one (i) gets excited into a non-fluorescing metastable state, or (ii) is of another isotopic species. Hopping rates of 1 s-1 are found at high thermal excitation. Elsewhere, the rates drop by two orders of magnitude, and vary resonantly with temperature near potential energy/kinetic energy = 15, where the bright ion's hopping upstream of the laser beam is five times more likely than downstream. Two discernible ions in a trap represent a microscopic model system for the study of reaction kinetics.

  3. RF Manipulation of Ions in the High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Martin, James J.; Sims, William H.; Chakrabarti, Suman; Lewis, Raymond A.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The annihilation of antimatter provides the highest mass specific energy of any other known reaction. Proper harnessing of this energy holds great promise for future space propulsion systems. Many different propulsion concepts have been proposed that take advantage of antimatter, either using matter-antimatter as the primary fuel, or as a 'spark plug' for fusion and fission systems. In order to begin to address these concepts experimentally, a method of storing and transporting antimatter must be developed. The High Performance Antiproton Trap (HiPAT) is a first-generation storage and transportation device designed to store and transport 10(exp 12) antiprotons with a storage half-life of 18 days. It uses a Penning-Malmberg ion trap with a 4T magnetic field and 20 kV potential. This will enable researchers much more flexibility in the design of antimatter experiments related to propulsion. Ions cannot be stored indefinitely in a real trap, as ion cloud instabilities develop from imperfections in manufacturing and misalignments in assembly. Previous work has been done at both the National Institute of Standards and University of California in San Diego in using RF (radio frequency) signals to both diagnose and confine the ion cloud. Two electrodes in the trap have been segmented to allow both reception and transmission of RF waves in the ion cloud. Experiments are underway to determine the number of ions and density in the cloud by "listening" to protons contained in the HiPAT. Currently we believe the density of ions stored in the trap is roughly 10(exp 15) m(exp -3). Development of non-destructive techniques is vital to the project goals, enabling continuous monitoring of the quantities stored in the system. Experimental work is also being done in identifying RF transmission frequencies that can manipulate the density of the cloud, by exchanging energy and momentum between the RF wave and the ions. Preliminary experiments have demonstrated this interaction.

  4. An integrated ion trap and time-of-flight mass spectrometer for chemical and photo- reaction dynamics studies.

    PubMed

    Schowalter, Steven J; Chen, Kuang; Rellergert, Wade G; Sullivan, Scott T; Hudson, Eric R

    2012-04-01

    We demonstrate the integration of a linear quadrupole trap with a simple time-of-flight mass spectrometer with medium-mass resolution (m/Δm ∼ 50) geared towards the demands of atomic, molecular, and chemical physics experiments. By utilizing a novel radial ion extraction scheme from the linear quadrupole trap into the mass analyzer, a device with large trap capacity and high optical access is realized without sacrificing mass resolution. This provides the ability to address trapped ions with laser light and facilitates interactions with neutral background gases prior to analyzing the trapped ions. Here, we describe the construction and implementation of the device as well as present representative ToF spectra. We conclude by demonstrating the flexibility of the device with proof-of-principle experiments that include the observation of molecular-ion photodissociation and the measurement of trapped-ion chemical reaction rates.

  5. Operational Parameters, Considerations, and Design Decisions for Resource-Constrained Ion Trap Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Danell, Ryan M.; VanAmerom, Friso H. W.; Pinnick, Veronica; Cotter, Robert J.; Brickerhoff, William; Mahaffy, Paul

    2011-01-01

    Mass spectrometers are increasingly finding applications in new and unique areas, often in situations where key operational resources (i.e. power, weight and size) are limited. One such example is the Mars Organic Molecule Analyzer (MOMA). This instrument is a joint venture between NASA and the European Space Agency (ESA) to develop an ion trap mass spectrometer for chemical analysis on Mars. The constraints on such an instrument are significant as are the performance requirements. While the ideal operating parameters for an ion trap are generally well characterized, methods to maintain analytical performance with limited power and system weight need to be investigated and tested. Methods Experiments have been performed on two custom ion trap mass spectrometers developed as prototypes for the MOMA instrument. This hardware consists of quadrupole ion trap electrodes that are 70% the size of common commercial instrumentation. The trapping RF voltage is created with a custom tank circuit that can be tuned over a range of RF frequencies and is driven using laboratory supplies and amplifiers. The entire instrument is controlled with custom Lab VIEW software that allows a high degree of flexibility in the definition of the scan function defining the ion trap experiment. Ions are typically generated via an internal electron ionization source, however, a laser desorption source is also in development for analysis of larger intact molecules. Preliminary Data The main goals in this work have been to reduce the power required to generate the radio frequency trapping field used in an ion trap mass spectrometer. Generally minimizing the power will also reduce the volume and mass of the electronics to support the instrument. In order to achieve optimum performance, commercial instruments typically utilize RF frequencies in the 1 MHz range. Without much concern for power usage, they simply generate the voltage required to access the mass range of interest. In order to reduce the

  6. Digital-Analog Quantum Simulation of Spin Models in Trapped Ions

    NASA Astrophysics Data System (ADS)

    Arrazola, Iñigo; Pedernales, Julen S.; Lamata, Lucas; Solano, Enrique

    2016-07-01

    We propose a method to simulate spin models in trapped ions using a digital-analog approach, consisting in a suitable gate decomposition in terms of analog blocks and digital steps. In this way, we show that the quantum dynamics of an enhanced variety of spin models could be implemented with substantially less number of gates than a fully digital approach. Typically, analog blocks are built of multipartite dynamics providing the complexity of the simulated model, while the digital steps are local operations bringing versatility to it. Finally, we describe a possible experimental implementation in trapped-ion technologies.

  7. Ion trap mass spectrometry on a comet nucleus: the Ptolemy instrument and the Rosetta space mission.

    PubMed

    Todd, John F J; Barber, Simeon J; Wright, Ian P; Morgan, Geraint H; Morse, Andrew D; Sheridan, Simon; Leese, Mark R; Maynard, Jon; Evans, Suzanne T; Pillinger, Colin T; Drummond, Duncan L; Heys, Samantha C; Huq, S Ejaz; Kent, Barry J; Sawyer, Eric C; Whalley, Martin S; Waltham, Nicholas R

    2007-01-01

    In May 2014, the Rosetta spacecraft is scheduled to rendezvous with the comet Churyumov-Gerasimenko ('67P'). One of the instruments on board the 'Lander' which will descend on to the surface of the comet is a miniaturised GC/MS system that incorporates an ion trap mass spectrometer, specially developed for isotope ratio analysis. This article describes the development and optimisation of the ion trap for this unique application, and presents a summary of the range of pre-programmed experiments that will contribute to the characterisation of the solid and volatile cometary materials.

  8. Resistive Interchange Modes Destabilized by Helically Trapped Energetic Ions in a Helical Plasma

    NASA Astrophysics Data System (ADS)

    Du, X. D.; Toi, K.; Osakabe, M.; Ohdachi, S.; Ido, T.; Tanaka, K.; Yokoyama, M.; Yoshinuma, M.; Ogawa, K.; Watanabe, K. Y.; Isobe, M.; Nagaoka, K.; Ozaki, T.; Sakakibara, S.; Seki, R.; Shimizu, A.; Suzuki, Y.; Tsuchiya, H.

    2015-04-01

    A new bursting m =1 /n =1 instability (m ,n : poloidal and toroidal mode numbers) with rapid frequency chirping down has been observed for the first time in a helical plasma with intense perpendicular neutral beam injection. This is destabilized in the plasma peripheral region by resonant interaction between helically trapped energetic ions and the resistive interchange mode. A large radial electric field is induced near the edge due to enhanced radial transport of the trapped energetic ions by the mode, and leads to clear change in toroidal plasma flow, suppression of microturbulence, and triggering an improvement of bulk plasma confinement.

  9. Ion trap mass spectrometry on a comet nucleus: the Ptolemy instrument and the Rosetta space mission.

    PubMed

    Todd, John F J; Barber, Simeon J; Wright, Ian P; Morgan, Geraint H; Morse, Andrew D; Sheridan, Simon; Leese, Mark R; Maynard, Jon; Evans, Suzanne T; Pillinger, Colin T; Drummond, Duncan L; Heys, Samantha C; Huq, S Ejaz; Kent, Barry J; Sawyer, Eric C; Whalley, Martin S; Waltham, Nicholas R

    2007-01-01

    In May 2014, the Rosetta spacecraft is scheduled to rendezvous with the comet Churyumov-Gerasimenko ('67P'). One of the instruments on board the 'Lander' which will descend on to the surface of the comet is a miniaturised GC/MS system that incorporates an ion trap mass spectrometer, specially developed for isotope ratio analysis. This article describes the development and optimisation of the ion trap for this unique application, and presents a summary of the range of pre-programmed experiments that will contribute to the characterisation of the solid and volatile cometary materials. PMID:17154436

  10. Digital-Analog Quantum Simulation of Spin Models in Trapped Ions

    PubMed Central

    Arrazola, Iñigo; Pedernales, Julen S.; Lamata, Lucas; Solano, Enrique

    2016-01-01

    We propose a method to simulate spin models in trapped ions using a digital-analog approach, consisting in a suitable gate decomposition in terms of analog blocks and digital steps. In this way, we show that the quantum dynamics of an enhanced variety of spin models could be implemented with substantially less number of gates than a fully digital approach. Typically, analog blocks are built of multipartite dynamics providing the complexity of the simulated model, while the digital steps are local operations bringing versatility to it. Finally, we describe a possible experimental implementation in trapped-ion technologies. PMID:27470970

  11. Magnetic mirror trap with electron-cyclotron plasma heating as a source of multiply charged ions

    SciTech Connect

    Golovanivskii, K.S.

    1986-03-01

    This paper presents the physical operating principles of sources of multiply charged ions using electron cyclotron resonance. It is shown that the conditions that must be satisfied for multiple ionization are well matched to the conditions of effective plasma confinement in a magnetic mirror trap when a collision mode of confinement is provided. Plasma stability with hot electrons in the mirror magnetic trap and the mechanisms of plasma heating by highfrequency fields are analyzed. Two sources of multiply charged ions with ECR plasma heating are examined. Evaluations of the future of this area are given.

  12. Aging process of I-cathode with magnetic ion trap

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaobing; Lei, Wei; Feng, Niangen; Havekes, Jos; Tong, Linsu; den Engelsen, Daniel

    2005-09-01

    An aging process, which applies a high frequency (HF) magnetic field on the electron gun during the aging process, is introduced to solve the unbalanced I-cathode emission slump. The effect is that the scanning electron beam and the HF magnetic field heat up the gun parts by electron bombarding and eddy current heating. In this way, the grids are effectively degassed. A part of the desorbed gases is pumped by the Ba-getter in the tube, whereas another part is ionized by electron collision. These ionized gas molecules, notably Ar +, are partially trapped in gun parts. Therefore, a lower residual gas pressure and emission slump can be achieved.

  13. The use of ion beam cleaning to obtain high quality cold welds with minimal deformation

    NASA Technical Reports Server (NTRS)

    Sater, B. L.; Moore, T. J.

    1978-01-01

    A variation of cold welding is described which utilizes an ion beam to clean mating surfaces prior to joining in a vacuum environment. High quality solid state welds were produced with minimal deformation.

  14. Advanced Automation for Ion Trap Mass Spectrometry-New Opportunities for Real-Time Autonomous Analysis

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Wong, C. M.; Salmonson, J. D.; Yost, R. A.; Griffin, T. P.; Yates, N. A.; Lawless, James G. (Technical Monitor)

    1994-01-01

    The utility of MS/MS for both target compound analysis and the structure elucidation of unknowns has been described in a number of references. A broader acceptance of this technique has not yet been realized as it requires large, complex, and costly instrumentation which has not been competitive with more conventional techniques. Recent advancements in ion trap mass spectrometry promise to change this situation. Although the ion trap's small size, sensitivity, and ability to perform multiple stages of mass spectrometry have made it eminently suitable for on-line, real-time monitoring applications, advance automation techniques are required to make these capabilities more accessible to non-experts. Towards this end we have developed custom software for the design and implementation of MS/MS experiments. This software allows the user to take full advantage of the ion trap's versatility with respect to ionization techniques, scan proxies, and ion accumulation/ejection methods. Additionally, expert system software has been developed for autonomous target compound analysis. This software has been linked to ion trap control software and a commercial data system to bring all of the steps in the analysis cycle under control of the expert system. These software development efforts and their utilization for a number of trace analysis applications will be described.

  15. Toward Visible-Wavelength Multi-Species Trapped-Ion Quantum Logic

    NASA Astrophysics Data System (ADS)

    Bruzewicz, Colin; McConnell, Robert; Loh, William; Sage, Jeremy; Chiaverini, John

    2016-05-01

    Large-scale quantum information processing and quantum networking using trapped ions will likely require multiple atomic species to allow for sympathetic cooling of ion vibrational modes, quantum state measurement without decoherence of unmeasured qubits, and interfacing with flying qubits. Inter-species quantum logic and quantum state transfer are key components of these tasks, particularly in the cases of quantum-error-correction syndrome extraction or remote entanglement generation using sympathetic ions. Multi-species logic and manipulation in a large processor will require control light of several wavelengths delivered to many ion-trap array sites in parallel, a challenge at short wavelengths. We report on progress toward sympathetic cooling and intra- and inter-species logic using Sr+ and Ca+ ions in surface-electrode trap arrays. These species admit optical control fields that can be routed using photonic waveguides straightforwardly integrated into the trap-array structure as their relevant transitions are accessible using visible and near-infra-red light.

  16. Ion Dynamic Capture Experiments With The High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Martin, James; Lewis, Raymond; Chakrabarti, Suman; Sims, William H.; Pearson, J. Boise; Fant, Wallace E.

    2002-01-01

    To take the first step towards using the energy produced from the matter-antimatter annihilation for propulsion applications, the NASA Marshall Space Flight Center (MSFC) Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. The High Performance Antiproton Trap (HiPAT) is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage electrode confinement system, and an ultra high vacuum test section. It has been designed with an ultimate goal of maintaining 10(exp 12) charged particles with a half-life of 18 days. Currently, this system is being evaluated experimentally using normal matter ions that are cheap to produce, relatively easy to handle, and provide a good indication of overall trap behavior (with the exception of assessing annihilation losses). The ions are produced via a positive hydrogen ion source and transported to HiPAT in a beam line equipped with electrostatic optics. The optics serve to both focus and gate the incoming ions, providing microsecond-timed beam pulses that are dynamically captured by cycling the HiPAT forward containment field like a "trap door". Initial dynamic capture experiments have been successfully performed with beam energy and currents set to 1.9 kV and 23 micro-amps, respectively. At these settings up to 2x10(exp 9) ions have been trapped during a single dynamic cycle.

  17. Technology for On-Chip Qubit Control with Microfabricated Surface Ion Traps

    SciTech Connect

    Highstrete, Clark; Scott, Sean Michael; Maunz, Peter Lukas Wilhelm; Tigges, Christopher P.; Blain, Matthew Glenn; Heller, Edwin J.; Stevens, James E.

    2013-11-01

    Trapped atomic ions are a leading physical system for quantum information processing. However, scalability and operational fidelity remain limiting technical issues often associated with optical qubit control. One promising approach is to develop on-chip microwave electronic control of ion qubits based on the atomic hyperfine interaction. This project developed expertise and capabilities at Sandia toward on-chip electronic qubit control in a scalable architecture. The project developed a foundation of laboratory capabilities, including trapping the 171Yb+ hyperfine ion qubit and developing an experimental microwave coherent control capability. Additionally, the project investigated the integration of microwave device elements with surface ion traps utilizing Sandia’s state-of-the-art MEMS microfabrication processing. This effort culminated in a device design for a multi-purpose ion trap experimental platform for investigating on-chip microwave qubit control, laying the groundwork for further funded R&D to develop on-chip microwave qubit control in an architecture that is suitable to engineering development.

  18. Two-dimensional ion crystals in radio-frequency traps for quantum simulation

    NASA Astrophysics Data System (ADS)

    Richerme, Philip

    2016-09-01

    The computational difficulty of solving fully quantum many-body spin problems is a significant obstacle to understanding the behavior of strongly correlated quantum matter. Experimental ion trap quantum simulation is a promising approach for studying these lattice spin models, but has so far been limited to one-dimensional systems. This work argues that such quantum simulation techniques are extendable to a two-dimensional (2D) ion crystal confined in a radio-frequency (rf) trap. Using appropriately chosen parameters, driven ion motion due to the rf fields can be made small and will not limit the types of quantum spin models that can be experimentally encoded. The rf-driven motion is calculated to modestly reduce the stability region of a 2D crystal and must be considered when designing the 2D trap. The system will be scalable to 100+ quantum particles, far beyond the realm of classical intractability, while maintaining the traditional ion trap strengths of individual-ion control, long quantum coherence times, and site-resolved projective spin measurements.

  19. Towards imaging the folding of single biomolecules in an ion trap

    NASA Astrophysics Data System (ADS)

    Streed, Erik

    2013-05-01

    Recent advances in imaging of single trapped atomic ions have demonstrated wavelength-scale fluorescence and absorption imaging (Streed et al. Nat. Comm 3, 933 (2012)). We propose adapting these imaging techniques to investigate the folding properties of biological molecules in the gas phase. Trapped-ion mass spectrometry is a well-established technique for compositional analysis of biomolecules from small proteins to whole virus particles. Confining single isolated biomolecules in an ion trap provides a uniquely adaptable environment in which to investigate higher-order folding dynamics through manipulation of the surrounding solvent cage, temperature, and net charge at the single quantum level. We propose to optically observe these changes in folding through statistical super-resolution microscopy of different fluorescent groups. To this end we show that wavelength-scale confinement of singly-charged high-mass biomolecular ions is feasible with established trap designs using room temperature buffer gas cooling. In this regime the translational thermal motion of the ion does not contribute substantially to optical spot width. Griffith University ASI Physical Sciences.

  20. An apparatus for immersing trapped ions into an ultracold gas of neutral atoms.

    PubMed

    Schmid, Stefan; Härter, Arne; Frisch, Albert; Hoinka, Sascha; Denschlag, Johannes Hecker

    2012-05-01

    We describe a hybrid vacuum system in which a single ion or a well-defined small number of trapped ions (in our case Ba(+) or Rb(+)) can be immersed into a cloud of ultracold neutral atoms (in our case Rb). This apparatus allows for the study of collisions and interactions between atoms and ions in the ultracold regime. Our setup is a combination of a Bose-Einstein condensation apparatus and a linear Paul trap. The main design feature of the apparatus is to first separate the production locations for the ion and the ultracold atoms and then to bring the two species together. This scheme has advantages in terms of stability and available access to the region where the atom-ion collision experiments are carried out. The ion and the atoms are brought together using a moving one-dimensional optical lattice transport which vertically lifts the atomic sample over a distance of 30 cm from its production chamber into the center of the Paul trap in another chamber. We present techniques to detect and control the relative position between the ion and the atom cloud.