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Sample records for atom trap trace

  1. Atom trap trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O' Connor, T. P.; Young, L.

    2000-05-25

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

  2. Isotopic abundance in atom trap trace analysis

    Science.gov (United States)

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  3. Atom trap trace analysis of {sup 39}Ar

    Energy Technology Data Exchange (ETDEWEB)

    Welte, Joachim

    2011-12-14

    Detection of {sup 39}Ar in natural water samples can be employed for radiometric dating on a timescale of 50 to 1000 years before present. This experimental work comprises the setup of an atomic beam and trap apparatus that captures and detects {sup 39}Ar atoms by the laser-cooling technique ''Atom Trap Trace Analysis''. With this approach, the limitations of low-level counting, regarding sample size and measurement time, could be overcome. In the course of this work, the hyperfine structure spectrum of the cooling transition 1s{sub 5}-2p{sub 9} has been experimentally determined. A high intensity, optically collimated beam of slow metastable argon atoms has been set up and fluorescence detection of individual {sup 39}Ar atoms in a magneto-optical trap is realized. {sup 39}Ar count rates of 1 atom in about 4 hours have been achieved for atmospheric argon. Recent improvements further suggest that even higher count rates of 1 atom/hour are within reach.

  4. Trace analyses at the single particle level with Atom Trap Trace Analysis for 39Ar

    International Nuclear Information System (INIS)

    Atom optics has found many applications in different fields of physics. In the context of environmental physics the method of Atom Trap Trace Analysis (ATTA) has opened a new level of dating of water in the regime of very old water (millions of years) with 81Kr and recent water of the last 1000 years with 39Ar. The latter is the topic of this seminar revealing the challenges and experimental solutions to work with 39Ar concentrations in Ar as small as 1:1016. After the detailed discussion of the experimental techniques I will present the first results on dating of water with this method [1] and discuss the potential for samples as small as 1 liter. Being able to date such small samples we will open up a route for detecting the age distribution of the oceans. (author)

  5. Single atom detection of calcium isotopes by atom trap trace analysis

    CERN Document Server

    Hoekstra, S; Morgenstern, R; Wilschut, H W; Hoekstra, R

    2005-01-01

    We demonstrate a combination of an isotopically purified atom beam and a magneto-optical trap which enables the single atom detection of all stable isotopes of calcium (40, 42, 43, 44, 46 and 48). These isotopes range in abundance from 96.9 % (40Ca) to 0.004 (46Ca). The trap is loaded from an atomic beam which is decelerated in a Zeeman slower and subsequently deflected over an angle of 30 degrees by optical molasses. The isotope selectivity of the Zeeman slower and the deflection stage is investigated experimentally and compared with Monte Carlo simulations.

  6. An atom trap trace analysis (ATTA) system for measuring ultra-low contamination by krypton in xenon dark matter detectors

    Science.gov (United States)

    Yoon, Tae Hyun

    The XENON dark matter experiment aims to detect hypothetical weakly interacting massive particles (WIMPs) scattering off nuclei within its liquid xenon (LXe) target. The trace 85Kr in the xenon target undergoes beta-decay with a 687 keV end point and 10.8 year halflife, which contributes background events and limits the sensitivity of the experiment. In order to achieve the desired sensitivity, the contamination by krypton is reduced to the part per trillion (ppt) level by cryogenic distillation. The conventional methods are not well suited for measuring the krypton contamination at such a low level. In this work, we have developed an atom trap trace analysis (ATTA) device to detect the ultra-low krypton concentration in the xenon target. This project was proposed to the National Science Foundation (NSF) as a Major Research Instrumentation (MRI) development [Aprile and Zelevinsky, 2009] and is funded by NSF and Columbia University. The ATTA method, originally developed at Argonne National Laboratory, uses standard laser cooling and trapping techniques, and counts single trapped atoms. Since the isotopic abundance of 85Kr in nature is 1.5 x 10-11, the 85Kr/Xe level is expected to be ˜10-23, which is beyond the capability of our method. Thus we detect the most abundant (57%) isotope 84Kr, and infer the 85Kr contamination from their known abundances. To avoid contamination by krypton, the setup is tested and optimized with 40 Ar which has a similar cooling wavelength to 84Kr. Two main challenges in this experiment are to obtain a trapping efficiency high enough to detect krypton impurities at the ppt level, and to achieve the resolution to discriminate single atoms. The device is specially designed and adjusted to meet these challenges. After achieving these criteria with argon gas, we precisely characterize the efficiency of the system using Kr-Xe mixtures with known ratios, and find that ˜90 minutes are required to trap one 84Kr atom at the 1-ppt Kr

  7. Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

    2016-01-01

    A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

  8. Atomic Coherent Trapping and Properties of Trapped Atom

    Institute of Scientific and Technical Information of China (English)

    YANG Guo-Jian; XIA Li-Xin; XIE Min

    2006-01-01

    Based on the theory of velocity-selective coherent population trapping, we investigate an atom-laser system where a pair of counterpropagating laser fields interact with a three-level atom. The influence of the parametric condition on the properties of the system such as velocity at which the atom is selected to be trapped, time needed for finishing the coherent trapping process, and possible electromagnetically induced transparency of an altrocold atomic medium,etc., is studied.

  9. Microchip-Based Trapped-Atom Clocks

    CERN Document Server

    Vuletic, Vladan; Schleier-Smith, Monika H

    2011-01-01

    This is a chapter of a recently published book entitled Atom Chips, edited by Jakob Reichel and Vladan Vuletic. The contents of this chapter include: Basic Principles; Atomic-Fountain versus Trapped-Atom Clocks; Optical-Transition Clocks versus Microwave Clocks; Clocks with Magnetically Trapped Atoms--Fundamental Limits and Experimental Demonstrations; Readout in Trapped-Atom Clocks; and Spin Squeezing.

  10. Cold atoms in videotape micro-traps

    Science.gov (United States)

    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.

  11. Cold atoms in videotape micro-traps

    CERN Document Server

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

    2005-01-01

    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 microkelvin 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.

  12. Characterizing optical dipole trap via fluorescence of trapped cesium atoms

    Institute of Scientific and Technical Information of China (English)

    LIU; Tao; GENG; Tao; YAN; Shubin; LI; Gang; ZHANG; Jing; WANG; Junmin; PENG; Kunchi; ZHANG; Tiancai

    2006-01-01

    Optical dipole trap (ODT) is becoming an important tool of manipulating neutral atoms. In this paper ODT is realized with a far-off resonant laser beam strongly focused in the magneto-optical trap (MOT) of cesium atoms. The light shift is measured by simply monitoring the fluorescence of the atoms in the magneto-optical trap and the optical dipole trap simultaneously. The advantages of our experimental scheme are discussed, and the effect of the beam waist and power on the potential of dipole trap as well as heating rate is analyzed.

  13. Optical wire trap for cold neutral atoms

    CERN Document Server

    Schneeweiss, Philipp; Rauschenbeutel, Arno

    2014-01-01

    We propose a trap for cold neutral atoms using a fictitious magnetic field induced by a nanofiber-guided light field. In close analogy to magnetic side-guide wire traps realized with current-carrying wires, a trapping potential can be formed when applying a homogeneous magnetic bias field perpendicular to the fiber axis. We discuss this scheme in detail for laser-cooled cesium atoms and find trap depths and trap frequencies comparable to the two-color nanofiber-based trapping scheme but with one order of magnitude lower powers of the trapping laser field. Moreover, the proposed scheme allows one to bring the atoms closer to the nanofiber surface, thereby enabling efficient optical interfacing of the atoms with additional light fields. Specifically, optical depths per atom, $\\sigma_0/A_{\\rm eff}$, of more than 0.4 are predicted, making this system eligible for nanofiber-based nonlinear and quantum optics experiments.

  14. Magnetic Trapping of Cold Bromine Atoms

    CERN Document Server

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

    2014-01-01

    Magnetic trapping of bromine atoms at temperatures in the milliKelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br$_2$ 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 only lost 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...

  15. Trapping atoms on a transparent permanent-magnet atom chip

    CERN Document Server

    Shevchenko, A; Jaakkola, A; Kaivola, M; Lindvall, T; Pfau, T; Tittonen, I

    2006-01-01

    We describe experiments on trapping of atoms in microscopic magneto-optical traps on an optically transparent permanent-magnet atom chip. The chip is made of magnetically hard ferrite-garnet material deposited on a dielectric substrate. The confining magnetic fields are produced by miniature magnetized patterns recorded in the film by magneto-optical techniques. We trap Rb atoms on these structures by applying three crossed pairs of counter-propagating laser beams in the conventional magneto-optical trapping (MOT) geometry. We demonstrate the flexibility of the concept in creation and in-situ modification of the trapping geometries through several experiments.

  16. Laser cooling and trapping of atoms

    OpenAIRE

    Townsend Christopher G.

    1995-01-01

    A detailed experimental and theoretical investigation of a magneto-optical trap for caesium atoms is presented. Particular emphasis has been placed on achieving high spatial number densities and low temperatures. Optimizing both of these together enables efficient evaporative cooling from a conservative trap, a procedure which has recently led to the first observations of Bose-Einstein condensation in a dilute atomic vapour. The behaviour of a magneto-optical trap is nomina...

  17. Trapping Rydberg Atoms in an Optical Lattice

    Science.gov (United States)

    Anderson, Sarah E.

    2012-06-01

    Optical lattice traps for Rydberg atoms are of interest in advanced science and in practical applications. After a brief discussion of these areas of interest, I will review some basics of optical Rydberg-atom trapping. The trapping potential experienced by a Rydberg atom in an optical lattice is given by the spatial average of the free-electron ponderomotive energy weighted by the Rydberg electron's probability distribution. I will then present experimental results on the trapping of ^85Rb Rydberg atoms in a one-dimensional ponderomotive optical lattice (wavelength 1064 nm). The principal methods employed to study the lattice performance are microwave spectroscopy, which is used to measure the lattice's trapping efficiency, and photo-ionization, which is used to measure the dwell time of the atoms in the lattice. I have achieved a 90% trapping efficiency for ^85Rb 50S atoms by inverting the lattice immediately after laser excitation of ground-state atoms into Rydberg states. I have characterized the dwell time of the atoms in the lattice using photo-ionization of 50D5/2 atoms. In continued work, I have explored the dependence of the Rydberg-atom trapping potential on the angular portion of the atomic wavefunction. Distinct angular states exhibit different trapping behavior in the optical lattice, depending on how their wavefunctions are oriented relative to the lattice planes. Specifically, I have measured the lattice potential depth of sublevels of ^85Rb nD atoms (50behavior varies substantially for the various angular sublevels, in agreement with theory. The talk will conclude with an outlook into planned experiments.

  18. An Atom Trap Relying on Optical Pumping

    CERN Document Server

    Bouyer, P; Dahan, M B; Michaud, A; Salomon, C; Dalibard, J

    1994-01-01

    We have investigated a new radiation pressure trap which relies on optical pumping and does not require any magnetic field. It employs six circularly polarized divergent beams and works on the red of a $J_{g} \\longrightarrow J_{e} = J_{g} + 1$ atomic transition with $J_{g} \\geq 1/2$. We have demonstrated this trap with cesium atoms from a vapour cell using the 852 nm $J_{g} = 4 \\longrightarrow J_{e} = 5$ resonance transition. The trap contained up to $3 \\cdot 10^{7}$ atoms in a cloud of $1/\\sqrt{e}$ radius of 330 $\\mu$m.

  19. Enhanced Magnetic Trap Loading for Atomic Strontium

    CERN Document Server

    Barker, D S; Pisenti, N C; Campbell, G K

    2015-01-01

    We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a Magneto-Optical Trap (MOT). This is achieved by adding a depumping laser tuned to the 3P1 to 3S1 (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65 % for the bosonic isotopes and up to 30 % for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.

  20. Standard Model tests with trapped radioactive atoms

    CERN Document Server

    Behr, J A; 10.1088/0954-3899/36/3/033101

    2009-01-01

    We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating elec...

  1. Nanostructured optical nanofibres for atom trapping

    CERN Document Server

    Daly, Mark; Phelan, Ciarán; Deasy, Kieran; Chormaic, Síle Nic

    2013-01-01

    We propose an optical dipole trap for cold neutral atoms based on the electric field produced from the evanescent fields in a hollow rectangular slot cut through an optical nanofibre. In particular, we discuss the trap performance in relation to laser-cooled rubidium atoms and show that a far off-resonance, blue-detuned field combined with the attractive surface-atom interaction potential from the dielectric material forms a stable trapping configuration. With the addition of a red-detuned field, we demonstrate how three dimensional confinement of the atoms at a distance of 140 - 200 nm from the fibre surface within the slot can be accomplished. This scheme facilitates optical coupling between the atoms and the nanofibre that could be exploited for quantum communication schemes using ensembles of laser-cooled atoms.

  2. Suppression of Dephasing of Optically Trapped Atoms

    CERN Document Server

    Andersen, M F; Grünzweig, T; Davidson, N

    2003-01-01

    Ultra-cold atoms trapped in an optical dipole trap and prepared in a coherent superposition of their hyperfine ground states, decohere as they interact with their environment. We demonstrate than the loss in coherence in an "echo" experiment, which is caused by mechanisms such as Rayleigh scattering, can be suppressed by the use of a new pulse sequence. We also show that the coherence time is then limited by mixing to other vibrational levels in the trap and by the finite lifetime of the internal quantum states of the atoms.

  3. Laser cooling and trapping of ytterbium atoms

    Institute of Scientific and Technical Information of China (English)

    Xin-ye XU; Wen-li WANG; Qing-hong ZHOU; Guo-hui LI; Hai-ling JIANG; Lin-fang CHEN; Jie YE; Zhi-hong ZHOU; Yin CAI; Hai-yao TANG; Min ZHOU

    2009-01-01

    The experiments on the laser cooling and trapping of ytterbium atoms are reported, including the two-dimensional transversal cooling, longitudinal velocity Zeeman deceleration, and a magneto-optical trap with a broadband transition at a wavelength of 399 nm. The magnetic field distributions along the axis of a Zeeman slower were measured and in a good agreement with the calculated results. Cold ytterbium atoms were produced with a number of about 107 and a temperature of a few milli-Kelvin.In addition, using a 556-nm laser, the excitations of cold tterbium atoms at 1S0-3p1 transition were observed. The ytterbium atoms will be further cooled in a 556-nm magneto-optical trap and loaded into a three-dimensional optical lattice to make an ytterbium optical clock.

  4. Collisional trap losses of cold, magnetically-trapped Br atoms

    CERN Document Server

    Lam, J; Softley, T P

    2014-01-01

    Near-threshold photodissociation of Br$_2$ from a supersonic beam produces slow bromine atoms that are trapped in the magnetic field minimum formed between two opposing permanent magnets. Here, we quantify the dominant trap loss rate due to collisions with two sources of residual gas: the background limited by the vacuum chamber base pressure, and the carrier gas during the supersonic gas pulse. The loss rate due to collisions with residual Ar in the background follows pseudo first-order kinetics, and the bimolecular rate coefficient for collisional loss from the trap is determined by measurement of this rate as a function of the background Ar pressure. This rate coefficient is smaller than the total elastic collision rate coefficient, as it only samples those collisions that lead to trap loss, and is determined to be $\\langle\

  5. A trapped atom interferometer with ultracold Sr atoms

    CERN Document Server

    Zhang, Xian; Mazzoni, Tommaso; Poli, Nicola; Tino, Guglielmo M

    2016-01-01

    We report on a trapped atom interferometer based on Bragg diffraction and Bloch oscillations with alkaline-earth-metal atoms. We use a Ramsey-Bord\\'e Bragg interferometer with $^{88}$Sr atoms combined with Bloch oscillations to extend the interferometer time. Thanks to a long coherence time for Bloch oscillations of $^{88}$Sr atoms, we observed interference up to 1 s evolution time in the lattice. A detailed study of decoherence sources during the Bloch phase is also presented. While still limited in sensitivity by lattice lifetime and beam inhomogeneity this result opens the way to high contrast trapped interferometers with extended interrogation time.

  6. Atomic hydrogen in a magnetic trap

    International Nuclear Information System (INIS)

    This thesis describes the construction and application of a static magnetic trap for atomic hydrogen. It is demonstrated that densities of up to 3*1014 cm-3 at temperatures of 80 to 200 mK can be achieved with a technically simple method of filling the trap. Double polarization is shown to occur spontaneously in the trapped gas, and the dipolar relaxation rate and its field dependance are measured confirming theoretical predictions. These results show that atomic hydrogen is a promising material for the achievement of Bose-Einstein condensation, provided that apart from the present method of cooling the gas, which is shown to impose a lower limit on the temperature, another cooling mechanism is supplied to reach lower temperatures. The density reached was two orders of magnitude higher than that of trapping experiments done at MIT where the technique of evaporate cooling was used to reach a temperature lower than 3 mK. (author). 138 refs.; 27 figs

  7. Virial theorems for trapped cold atoms

    OpenAIRE

    Werner, Félix

    2008-01-01

    A few small corrections We present a general virial theorem for quantum particles with arbitrary zero-range or finite-range interactions in an arbitrary external potential. We deduce virial theorems for several situations relevant to trapped cold atoms: zero-range interactions with and without Efimov effect, hard spheres, narrow Feshbach resonances, and finite-range interactions. If the scattering length $a$ is varied adiabatically in the BEC-BCS crossover, we find that the trapping potent...

  8. Introduction to light forces, atom cooling, and atom trapping

    OpenAIRE

    Savage, Craig,

    1995-01-01

    This paper introduces and reviews light forces, atom cooling and atom trapping. The emphasis is on the physics of the basic processes. In discussing conservative forces the semi-classical dressed states are used rather than the usual quantized field dressed states.

  9. Field theory for trapped atomic gases

    NARCIS (Netherlands)

    Stoof, H.T.C.

    2001-01-01

    In this course we give a selfcontained introduction to the quantum field theory for trapped atomic gases, using functional methods throughout. We consider both equilibrium and nonequilibrium phenomena. In the equilibrium case, we first derive the appropriate Hartree—Fock theory for the properties of

  10. Field theory for trapped atomic gases

    NARCIS (Netherlands)

    Stoof, H.T.C.

    2001-01-01

    In this course we give a selfcontained introduction to the quantum field theory for trapped atomic gases, using functional methods throughout. We consider both equilibrium and nonequilibrium phenomena. In the equilibrium case, we first derive the appropriate Hartree-Fock theory for the properties of

  11. Quantum state control of trapped Holmium atoms

    Science.gov (United States)

    Hostetter, James; Yip, Christopher; Milner, William; Booth, Donald; Collett, Jeffrey; Saffman, Mark

    2016-05-01

    Neutral Holmium with its large number of hyperfine ground states provides a promising approach for collective encoding of a multi-qubit register. A prerequisite for collective encoding is the ability to prepare different states in the 128 state hyperfine ground manifold. We report progress towards optical pumping and control of the hyperfine Zeeman state of trapped Ho atoms. Atoms are transferred from a 410.5 nm MOT into a 455 nm optical dipole trap. The atoms can be optically pumped using light driving the ground 6s2 , F = 11 to 6 s 6 p ,F' = 11 transition together with a F = 10 to F' = 11 repumper. Microwave fields are then used to drive transitions to hyperfine levels with 4 <= F <= 11 . Work supported by NSF award PHY-1404357.

  12. Boson Josephson Junction with Trapped Atoms

    Science.gov (United States)

    Raghavan, S.; Smerzi, A.; Fantoni, S.; Shenoy, S. R.

    We consider coherent atomic tunneling between two weakly coupled Bose-Einstein condensates at T=0 in a double-well trap. The condensate dynamics of the macroscopic amplitudes in the two wells is modeled by two Gross-Pitaevskii equations (GPE) coupled by a tunneling matrix element. Analytic elliptic function solutions are obtained for the time evolution of the inter-well fractional population imbalance z(t) (related to the condensate phase difference) of the Boson Josephson junction (BJJ). Surprisingly, the neutral-atom BJJ shows (non-sinusoidal generalizations of) effects seen in charged-electron superconductor Josephson junctions (SJJ). The BJJ elliptic-function behavior has a singular dependence on a GPE parameter ratio Λ at a critical ratio Λ=Λc, beyond which a novel 'macroscopic quantum self-trapping' effect sets in with a non-zero time-averaged imbalance ≠0.

  13. Magneto-Optical Trapping of Holmium Atoms

    CERN Document Server

    Miao, J; Stratis, G; Saffman, M

    2014-01-01

    We demonstrate sub-Doppler laser cooling and magneto-optical trapping of the rare earth element Holmium. Atoms are loaded from an atomic beam source and captured in six-beam $\\sigma_+ - \\sigma_-$ molasses using a strong $J=15/2 \\leftrightarrow J=17/2$ cycling transition at $\\lambda=410.5~\\rm nm$. Due to the small difference in hyperfine splittings and Land\\'e $g$-factors in the lower and upper levels of the cooling transition the MOT is self-repumped without additional repump light, and deep sub-Doppler cooling is achieved with the magnetic trap turned on. We measure the leakage out of the cycling transition to metastable states and find a branching ratio $\\sim 10^{-5}$ which is adequate for state resolved measurements on hyperfine encoded qubits.

  14. Continuous magnetic trapping of laser cooled atoms

    International Nuclear Information System (INIS)

    The authors present here initial results of the deceleration of a thermal atomic beam from -- 1000 to -- 100 m/s. The experiment was conducted in the 1.4-m long vertical superconducting solenoid which produced the slowing field. The fluorescence of the slowed atomic beam has been studied as a function of laser frequency. Figure 2 is a 12-GHz scan showing the fluorescence at a position 150 cm from the beginning of the solenoid. The wide peak corresponds to unslowed atoms with generally the initial velocity distribution. The second, narrower, peak corresponds to slowed atoms with a velocity of -- 150 m/s. Similar spectra have been obtained for various positions along the magnetic slower and trap. These data should allow better understanding of the cooling process and will be compared to computer models

  15. Two dipolar atoms in a harmonic trap

    Science.gov (United States)

    Ołdziejewski, Rafał; Górecki, Wojciech; Rzążewski, Kazimierz

    2016-05-01

    Two identical dipolar atoms moving in a harmonic trap without an external magnetic field are investigated. Using the algebra of angular momentum we reduce the problem to a simple numerics. We show that the internal spin-spin interactions between the atoms couple to the orbital angular momentum causing an analogue of the Einstein-de Haas effect. We show a possibility of adiabatically pumping our system from the s-wave to the d-wave relative motion. The effective spin-orbit coupling occurs at anti-crossings of the energy levels.

  16. Quasi-Magic optical traps for Rydberg atoms

    CERN Document Server

    Zhang, S; Saffman, M

    2011-01-01

    We propose blue-detuned optical traps that are suitable for trapping of both ground state and Rydberg excited atoms. Addition of a background compensation field or suitable choice of the trap geometry provides a magic trapping condition for ground and Rydberg atoms at the trap center. Deviations from the magic condition at finite temperature are calculated. Designs that achieve less than 200 kHz differential trap shift between Cs ground and 125s Rydberg states for 10 {\\mu}K Cs atoms are presented. Consideration of the trapping potential and photoionization rates

  17. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    Subodh R Shenoy

    2002-02-01

    We obtain the dynamics in number and phase difference, for Bose condensates that tunnel between two wells of a double-well atomic trap, using the (nonlinear) Gross–Pitaevskii equation. The dynamical equations are of the canonical form for the two conjugate variables, and the Hamiltonian corresponds to that of a momentum-shortened pendulum, supporting a richer set of tunneling oscillation modes than for a superconductor Josephson junction, that has a fixed-length pendulum as a mechanical model. Novel modes include ‘inverted pendulum’ oscillations with an average angle of ; and oscillations about a self-maintained population imbalance that we term ‘macroscopic quantum self-trapping’. Other systems with this phase-number nonlinear dynamics include two-component (interconverting) condensates in a single harmonic trap, and He3B superfluids in two containers connected by micropores.

  18. Anisotropic optical trapping of ultracold erbium atoms

    CERN Document Server

    Lepers, Maxence; Dulieu, Olivier; --,

    2013-01-01

    Ultracold atoms confined in a dipole trap are submitted to a potential whose depth is proportional to the real part of their dynamic dipole polarizability. The atoms also experience photon scattering whose rate is proportional to the imaginary part of their dynamic dipole polarizability. In this article we calculate the complex dynamic dipole polarizability of ground-state erbium, a rare-earth atom that was recently Bose-condensed. The polarizability is calculated with the sum-over-state formula inherent to second-order perturbation theory. The summation is performed on transition energies and transition dipole moments from ground-state erbium, which are computed using the Racah-Slater least-square fitting procedure provided by the Cowan codes. This allows us to predict 9 unobserved odd-parity energy levels of total angular momentum J=5, 6 and 7, in the range 25000-31000 cm-1 above the ground state. Regarding the trapping potential, we find that ground-state erbium essentially behaves like a spherically-symme...

  19. Combined ion and atom trap for low temperature ion-atom physics

    OpenAIRE

    Ravi, K.; LEE, Seunghyun; Sharma, Arijit; Werth, G.; Rangwala, S. A.

    2010-01-01

    We report an experimental apparatus and technique which simultaneously traps ions and cold atoms with spatial overlap. Such an apparatus is motivated by the study of ion-atom processes at temperatures ranging from hot to ultra-cold. This area is a largely unexplored domain of physics with cold trapped atoms. In this article we discuss the general design considerations for combining these two traps and present our experimental setup. The ion trap and atom traps are characterized independently ...

  20. Cold atom-ion experiments in hybrid traps

    OpenAIRE

    Härter, Arne; Denschlag, Johannes Hecker

    2013-01-01

    In the last 5 years, a novel field of physics and chemistry has developed in which cold trapped ions and ultracold atomic gases are brought into contact with each other. Combining ion traps with traps for neutral atoms yields a variety of new possibilities for research and experiments. These range from studies of cold atom-ion collisions and atom-ion chemistry to applications in quantum information science and condensed matter related research. In this article we give a brief introduction int...

  1. Halo Tracing with Atomic Hydrogen

    CERN Document Server

    Merrifield, M R

    2001-01-01

    This paper reviews the constraints that can be placed on the shapes of disk galaxies' dark halos using the distribution and kinematics of atomic hydrogen. These data indicate that dark halos are close to axisymmetric, with their axes of symmetry co-aligned with their disk axes. They also appear to be oblate, with shortest-to-longest axis ratios displaying quite a broad range of values from ~0.2 to ~0.8. These results are consistent with the predicted shapes of halos in cold dark matter scenarios, but rule out some of the more exotic dark matter candidates. However, the total number of measurements is still depressingly small, and more data are required if halo shape is to become a powerful diagnostic for theories of galaxy formation and evolution.

  2. Doppler cooling of an optically dense cloud of trapped atoms

    CERN Document Server

    Schmidt, P O; Werner, J; Binhammer, T; Görlitz, A; Pfau, T; Schmidt, Piet O.; Hensler, Sven; Binhammer, Thomas; G\\"{o}rlitz, Axel; Pfau, Tilman

    2002-01-01

    We have studied a general technique for laser cooling a cloud of polarized trapped atoms down to the Doppler temperature. A one-dimensional optical molasses using polarized light cools the axial motional degree of freedom of the atoms in the trap. Cooling of the radial degrees of freedom can be modelled by reabsorption of scattered photons in the optically dense cloud. We present experimental results for a cloud of chromium atoms in a magnetic trap. A simple model based on rate equations shows quantitative agreement with the experimental results. This scheme allows us to readily prepare a dense cloud of atoms in a magnetic trap with ideal starting conditions for evaporative cooling.

  3. Nanofiber-based optical trapping of cold neutral atoms

    CERN Document Server

    Vetsch, Eugen; Mitsch, Rudolf; Reitz, Daniel; Schneeweiss, Philipp; Rauschenbeutel, Arno

    2012-01-01

    We present experimental techniques and results related to the optimization and characterization of our nanofiber-based atom trap [Vetsch et al., Phys. Rev. Lett. 104, 203603 (2010)]. The atoms are confined in an optical lattice which is created using a two-color evanescent field surrounding the optical nanofiber. For this purpose, the polarization state of the trapping light fields has to be properly adjusted. We demonstrate that this can be accomplished by analyzing the light scattered by the nanofiber. Furthermore, we show that loading the nanofiber trap from a magneto-optical trap leads to sub-Doppler temperatures of the trapped atomic ensemble and yields a sub-Poissonian distribution of the number of trapped atoms per trapping site.

  4. A toroidal trap for the cold $^{87}Rb$ atoms using a rf-dressed quadrupole trap

    CERN Document Server

    Chakraborty, A; Ram, S P; Tiwari, S K; Rawat, H S

    2015-01-01

    We demonstrate the trapping of cold $^{87}Rb$ atoms in a toroidal geometry using a rf-dressed quadrupole magnetic trap formed by superposing a strong radio frequency (rf) field on a quadrupole trap. This rf-dressed quadrupole trap has minimum of the potential away from the quadrupole trap centre on a circular path which facilitates the trapping in the toroidal geometry. In the experiments, the laser cooled atoms were first trapped in the quadrupole trap, then cooled evaporatively using a weak rf-field, and finally trapped in the 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 rf-dressing of atoms. The atoms trapped in the toroidal trap may have applications in realization of an atom gyroscope as well as in studying the quantum gases in low dimensions.

  5. Analysis of the atom-number correlation function in a few-atom trap

    OpenAIRE

    Choi, Youngwoon; Yoon, Seokchan; Kang, Sungsam; Kim, Woongnae; Lee, Jai-Hyung; An, Kyungwon

    2006-01-01

    Stochastic properties of loading and loss mechanism in a few atom trap are analyzed. An approximate formula is derived for the atom-number correlation function for the trapped atoms in the limit of reasonably small two-atom loss rate. Validity of the approximate formula is confirmed by numerical simulations.

  6. Bichromatic State-insensitive Trapping of Caesium Atoms

    OpenAIRE

    Metbulut, M. M.; Renzoni, F.

    2015-01-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required w...

  7. Trapping of molecular Oxygen together with Lithium atoms

    CERN Document Server

    Akerman, Nitzan; Segev, Yair; Bibelnik, Natan; Narevicius, Julia; Narevicius, Edvardas

    2016-01-01

    We demonstrate simultaneous deceleration and trapping of a cold atomic and molecular mixture. This is the first step towards studies of cold atom-molecule collisions at low temperatures as well as application of sympathetic cooling. Both atoms and molecules are cooled in a supersonic expansion and are loaded into a moving magnetic trap which brings them to rest via the Zeeman interaction from an initial velocity of 375 m/s. We use a beam seeded with molecular Oxygen, and entrain it with Lithium atoms by laser ablation prior to deceleration. The deceleration ends with loading of the mixture into a static quadrupole trap, which is generated by two permanent magnets. We estimate $10^9$ trapped O$_2$ molecules and $10^5$ Li atoms with background pressure limited lifetime on the order of 1 second. With further improvements to Lithium entrainment we expect that sympathetic cooling of molecules is within reach.

  8. Dynamics of atom trapping in an rf-dressed potential

    CERN Document Server

    Chakraborty, A; Ram, S P; Tiwari, S K; Rawat, H S

    2016-01-01

    The dynamics of atom trapping in a radio-frequency-dressed-state potential formed by static and radio frequency (rf) fields has been studied using the Direct Simulation Monte Carlo (DSMC) technique. Using the simulations, a case of formation of a toroidal trap for cold $^{87}Rb$ atoms is investigated for atoms trapped in a static quadrupole magnetic trap and exposed to an rf-field with temporally increasing amplitude and decreasing frequency. We first calculate the adiabatic rf-dressed potential for an atom interacting with these fields and then apply DSMC algorithm to simulate the motion of the atom in this time dependent adiabatic potential. In the simulations the Landau-Zener (LZ) transition probability is calculated to know if the atom is in the trappable or untrappable dressed state. The results show that, initially at lower rf-field strength, the rf-field ejects atoms from the trap and leads to evaporative cooling of the atom cloud. However at higher rf-field strength, the atoms make LZ transition to th...

  9. Trapping fermionic and bosonic helium atoms

    NARCIS (Netherlands)

    Stas, R.J.W.

    2005-01-01

    This thesis presents experimental and theoretical work performed at the Laser Centre of the Vrije Universiteit in Amsterdam to study laser-cooled metastable triplet helium atoms. Samples containing about 3x10^8 helium atoms-either fermionic helium-3 atoms, bosonic helium-4 atoms or mixtures thereof

  10. Optical molasses, laser traps, and ultracold atoms

    International Nuclear Information System (INIS)

    There is dramatic progress in the demonstration of the mechanical effects of light on atoms. The laser cooling and stopping of atoms in an atomic beam were followed by the 3-D cooling and confinement of atoms with laser light. The authors survey the recent major experimental advances and try to point out some interesting physics that can be done in this newly accessible domain of gaseous atoms at low temperatures and possibly high densities

  11. A Novel Gravito-Optical Surface Trap for Neutral Atoms

    Institute of Scientific and Technical Information of China (English)

    XIE Chun-Xia; WANG Zhengling; YIN Jian-Ping

    2006-01-01

    @@ We propose a novel gravito-optical surface trap (GOST) for neutral atoms based on one-dimensional intensity gradient cooling. The surface optical trap is composed of a blue-detuned reduced semi-Gaussian laser beam (SGB), a far-blue-detuned dark hollow beam and the gravity field.

  12. Efficient Direct Evaporative Cooling in an Atom Chip Magnetic Trap

    CERN Document Server

    Farkas, Daniel M; Du, Shengwang; Anderson, Dana

    2013-01-01

    We demonstrate direct evaporative cooling of $^{87}$Rb atoms confined in a dimple trap produced by an atom chip. By changing the two chip currents and two external bias fields, we show theoretically that the trap depth can be lowered in a controlled way with no change in the trap frequencies or the value of the field at the trap center. Experimentally, we maximized the decrease in trap depth by allowing some loosening of the trap. In total, we reduced the trap depth by a factor of 20. The geometric mean of the trap frequencies was reduced by less than a factor of 6. The measured phase space density in the final two stages increased by more than two orders of magnitude, and we estimate an increase of four orders of magnitude over the entire sequence. A subsequent rf evaporative sweep of only a few megahertz produced Bose-Einstein condensates. We also produce condensates in which raising the trap bottom pushes hotter atoms into an rf "knife" operating at a fixed frequency of 5\\,MHz.

  13. Manipulating Neutral Atoms in Chip-Based Magnetic Traps

    Science.gov (United States)

    Aveline, David; Thompson, Robert; Lundblad, Nathan; Maleki, Lute; Yu, Nan; Kohel, James

    2009-01-01

    Several techniques for manipulating neutral atoms (more precisely, ultracold clouds of neutral atoms) in chip-based magnetic traps and atomic waveguides have been demonstrated. Such traps and waveguides are promising components of future quantum sensors that would offer sensitivities much greater than those of conventional sensors. Potential applications include gyroscopy and basic research in physical phenomena that involve gravitational and/or electromagnetic fields. The developed techniques make it possible to control atoms with greater versatility and dexterity than were previously possible and, hence, can be expected to contribute to the value of chip-based magnetic traps and atomic waveguides. The basic principle of these techniques is to control gradient magnetic fields with suitable timing so as to alter a trap to exert position-, velocity-, and/or time-dependent forces on atoms in the trap to obtain desired effects. The trap magnetic fields are generated by controlled electric currents flowing in both macroscopic off-chip electromagnet coils and microscopic wires on the surface of the chip. The methods are best explained in terms of examples. Rather than simply allowing atoms to expand freely into an atomic waveguide, one can give them a controllable push by switching on an externally generated or a chip-based gradient magnetic field. This push can increase the speed of the atoms, typically from about 5 to about 20 cm/s. Applying a non-linear magnetic-field gradient exerts different forces on atoms in different positions a phenomenon that one can exploit by introducing a delay between releasing atoms into the waveguide and turning on the magnetic field.

  14. Eliminating light shifts in single-atom optical traps

    CERN Document Server

    Hutzler, Nicholas R; Yu, Yichao; Ni, Kang-Kuen

    2016-01-01

    Microscopically controlled neutral atoms in optical tweezers and lattices have led to exciting advances in the study of quantum information and quantum many-body systems. The light shifts of atomic levels from the trapping potential in these systems can result in detrimental effects such as fluctuating dipole force heating, inhomogeneous detunings, and inhibition of laser cooling, which limits the atomic species that can be manipulated. In particular, these light shifts can be large enough to prevent loading into optical tweezers directly from a magneto-optical trap. We present a general solution to these limitations by loading, cooling, and imaging single atoms with temporally alternating beams. Because this technique does not depend on any specific spectral properties, we expect it to enable the optical tweezer method to control nearly any atomic or molecular species that can be laser cooled and optically trapped. Furthermore, we present an analysis of the role of heating and required cooling for single ato...

  15. Studies of Ultracold Strontium Atoms in an Optical Dipole Trap

    Science.gov (United States)

    Traverso, A. J.; Martinez de Escobar, Y. N.; Mickelson, P. G.; Killian, T. C.

    2008-05-01

    We survey recent experiments with ultracold strontium performed in our group. Trapping and cooling occurs in three stages: successive magneto-optical traps (MOTs) operating on 461 nm and 689 nm transitions of strontium, respectively, are loaded to cool atoms to a temperature of 1 μK. Finally, atoms are loaded into a far-off-resonance optical dipole trap (ODT). We examine the loading characteristics, thermalization, and lifetime of atoms held within the ODT. We also perform spectroscopy of atoms held within the ODT. During laser cooling, we are able to manipulate the energy levels of the atoms and shelve them into metastable states using 707 nm and 3 μm lasers. These experiments reveal interesting physics of ultracold strontium.

  16. In-trap fluorescence detection of atoms in a microscopic dipole trap

    CERN Document Server

    Hilliard, A J; Sompet, P; Carpentier, A V; Andersen, M F

    2015-01-01

    We investigate fluorescence detection using a standing wave of blue-detuned light of one or more atoms held in a deep, microscopic dipole trap. The blue-detuned standing wave realizes a Sisyphus laser cooling mechanism so that an atom can scatter many photons while remaining trapped. When imaging more than one atom, the blue detuning limits loss due to inelastic light-assisted collisions. Using this standing wave probe beam, we demonstrate that we can count from one to the order of 100 atoms in the microtrap with sub-poissonian precision.

  17. Deep optical trap for cold alkaline-Earth atoms.

    Science.gov (United States)

    Cruz, Luciano S; Sereno, Milena; Cruz, Flavio C

    2008-03-01

    We describe a setup for a deep optical dipole trap or lattice designed for holding atoms at temperatures of a few mK, such as alkaline-Earth atoms which have undergone only regular Doppler cooling. We use an external optical cavity to amplify 3.2 W from a commercial single-frequency laser at 532 nm to 523 W. Powers of a few kW, attainable with low-loss optics or higher input powers, allow larger trap volumes for improved atom transfer from magneto-optical traps. We analyze possibilities for cooling inside the deep trap, the induced Stark shifts for calcium, and a cancellation scheme for the intercombination clock transition using an auxiliary laser. PMID:18542375

  18. Analysis of a single-atom dipole trap

    International Nuclear Information System (INIS)

    We describe a simple experimental technique which allows us to store a single 87Rb atom in an optical dipole trap. Due to light-induced two-body collisions during the loading stage of the trap the maximum number of captured atoms is locked to one. This collisional blockade effect is confirmed by the observation of photon antibunching in the detected fluorescence light. The spectral properties of single photons emitted by the atom were studied with a narrow-band scanning cavity. We find that the atomic fluorescence spectrum is dominated by the spectral width of the exciting laser light field. In addition we observe a spectral broadening of the atomic fluorescence light due to the Doppler effect. This allows us to determine the mean kinetic energy of the trapped atom corresponding to a temperature of 105 μK. This simple single-atom trap is the key element for the generation of atom-photon entanglement required for future applications in quantum communication and a first loophole-free test of Bell's inequality

  19. Trapping fermionic and bosonic helium atoms

    OpenAIRE

    Stas, R. J. W.

    2005-01-01

    This thesis presents experimental and theoretical work performed at the Laser Centre of the Vrije Universiteit in Amsterdam to study laser-cooled metastable triplet helium atoms. Samples containing about 3x10^8 helium atoms-either fermionic helium-3 atoms, bosonic helium-4 atoms or mixtures thereof-are cooled to a temperature around 1 mK and form the starting point of the presented studies. The studies include an investigation of cold ionizing collisions in the absence of resonant light, an i...

  20. Atom-molecule collisions in an optically trapped gas

    OpenAIRE

    Zahzam, Nassim; Vogt, Thibault; Mudrich, Marcel; Comparat, Daniel; Pillet, Pierre

    2005-01-01

    Cold inelastic collisions between confined cesium (Cs) atoms and Cs$\\_2$ molecules are investigated inside a CO$\\_2$ laser dipole trap. Inelastic atom-molecule collisions can be observed and measured with a rate coefficient of $\\sim 2.5 \\times 10^{-11} $cm$^3$ s$^{-1}$, mainly independent of the molecular ro-vibrational state populated. Lifetimes of purely atomic and molecular samples are essentially limited by rest gas collisions. The pure molecular trap lifetime ranges 0,3-1 s, four times s...

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

    Science.gov (United States)

    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.

  2. PYRAMIDAL-HOLLOW-BEAM DIPOLE TRAP FOR ALKALI ATOMS

    Institute of Scientific and Technical Information of China (English)

    YIN JIAN-PING; GAO WEI-JIAN; WANG YU-ZHU; ZHU YI-FU; WANG YI-QIU

    2000-01-01

    We propose a dark gravito-optical dipole trap, for alkali atoms, consisting of a blue-detuned, pyramidal-hollow laser beam propagating upward and the gravity field. When cold atoms from a magneto-optical trap are loaded into the pyramidal-hollow beam and bounce inside the pyramidal-hollow beam, they experience efficient Sisyphus cooling and geometric cooling induced by the pyramidal-hollow beam and the weak repumping beam propagating downward. Our study shows that an ultracold and dense atomic sample with an equilibrium 3D momentum of ~ 3hk and an atomic density above the point of Bose-Einstein condensation may be obtained in this pure optical trap.

  3. Oscillation Frequencies for Simultaneous Trapping of Heteronuclear Alkali Atoms

    CERN Document Server

    Kaur, Kiranpreet; Arora, Bindiya

    2016-01-01

    We investigate oscillation frequencies for simultaneous trapping of more than one type of alkali atoms in a common optical lattice. For this purpose, we present numerical results for magic trapping conditions, where the oscillation frequencies for two different kind of alkali atoms using laser lights in the wavelength range 500-1200 nm are same. These wavelengths will be of immense interest for studying static and dynamic properties of boson-boson, boson-fermion, fermion-fermion, and boson-boson-boson mixtures involving different isotopes of Li, Na, K, Rb, Cs and Fr alkali atoms. In addition to this, we were also able to locate a magic wavelength around 808.1 nm where all the three Li, K, and Rb atoms are found to be suitable for oscillating at the same frequency in a common optical trap.

  4. A quasi-electrostatic trap for neutral atoms

    International Nuclear Information System (INIS)

    This thesis reports on the realization of a ''quasi-electrostatic trap'' (QUEST) for neutral atoms. Cesium (133Cs) and Lithium (7Li) atoms are stored, which represents for the first time a mixture of different species in an optical dipole trap. The trap is formed by the focused Gaussian beam of a 30 W cw CO2-laser. For a beam waist of 108 μm the resulting trap depth is κB x 118 μK for Cesium and κB x 48 μK for Lithium. We transfer up to 2 x 106 Cesium and 105 Lithium atoms from a magneto-optical trap into the QUEST. When simultaneously transferred, the atom number currently is reduced by roughly a factor of 10. Since photon scattering from the trapping light can be neglected, the QUEST represents an almost perfect conservative trapping potential. Atoms in the QUEST populate the electronic ground state sublevels. Arbitrary sublevels can be addressed via optical pumping. Due to the very low background gas pressure of 2 x 10-11 mbar storage times of several minutes are realized. Evaporative cooling of Cesium is observed. In addition, laser cooling is applied to the trapped Cesium sample, which reduces the temperature from 25 μK to a value below 7 μK. If prepared in the upper hyper-fine ground state sublevel, spin changing collisions are observed not only within one single species, but also between the two different species. The corresponding relaxation rates are quantitatively analyzed. (orig.)

  5. Cold Atom Source Containing Multiple Magneto-Optical Traps

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  7. Collisional properties of trapped cold chromium atoms

    CERN Document Server

    Pavlovich, Z; Côté, R; Sadeghpour, H R; Pavlovic, Zoran; Roos, Bjoern O.; Côté, Robin

    2004-01-01

    We report on calculations of the elastic cross section and thermalization rate for collision between two maximally spin-polarized chromium atoms in the cold and ultracold regimes, relevant to buffer-gas and magneto-optical cooling of chromium atoms. We calculate ab initio potential energy curves for Cr2 and the van der Waals coefficient C6, and construct interaction potentials between two colliding Cr atoms. We explore the effect of shape resonances on elastic cross section, and find that they dramatically affect the thermalization rate. Our calculated value for the s-wave scattering length is compared in magnitude with a recent measurement at ultracold temperatures.

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

    Science.gov (United States)

    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.

  9. Construction of a single atom trap for quantum information protocols

    Science.gov (United States)

    Shea, Margaret E.; Baker, Paul M.; Gauthier, Daniel J.; Duke Physics Department Team

    2016-05-01

    The field of quantum information science addresses outstanding problems such as achieving fundamentally secure communication and solving computationally hard problems. Great progress has been made in the field, particularly using photons coupled to ions and super conducting qubits. Neutral atoms are also interesting for these applications and though the technology for control of neutrals lags behind that of trapped ions, they offer some key advantages: primarily coupling to optical frequencies closer to the telecom band than trapped ions or superconducting qubits. Here we report progress on constructing a single atom trap for 87 Rb. This system is a promising platform for studying the technical problems facing neutral atom quantum computing. For example, most protocols destroy the trap when reading out the neutral atom's state; we will investigate an alternative non-destructive state detection scheme. We detail the experimental systems involved and the challenges addressed in trapping a single atom. All of our hardware components are off the shelf and relatively inexpensive. Unlike many other systems, we place a high numerical aperture lens inside our vacuum system to increase photon collection efficiency. We gratefully acknowledge the financial support of the ARO through Grant # W911NF1520047.

  10. Laser cooling, trapping, and Rydberg spectroscopy of neutral holmium atoms

    Science.gov (United States)

    Hostetter, James Allen

    This thesis focuses on progress towards using ensembles of neutral holmium for use in quantum computing operations. We are particularly interested in using a switchable interaction between neutral atoms, the Rydberg blockade, to implement a universal set of quantum gates in a collective encoding scheme that presents many benefits over quantum computing schemes which rely on physically distinct qubits. We show that holmium is uniquely suited for operations in a collective encoding basis because it has 128 ground hyperfine states, the largest number of any stable, neutral atom. Holmium is a rare earth atom that is very poorly described for our purposes as it has never been cooled and trapped, its spectrum is largely unknown, and it presents several unique experimental challenges related to its complicated atomic structure and short wavelength transitions. We demonstrate important progress towards overcoming these challenges. We produce the first laser cooling and trapping of holmium into a MOT. Because we use a broad cooling transition, our cooling technique does not require the use of a Zeeman slower. Using MOT depletion spectroscopy, we provide precise measurements of holmium's Rydberg states and its ionization potential. Our work continues towards cooling holmium into a dipole trap by calculating holmium's AC polarizability and demonstrating the results of early attempts at an optical dipole trap. We provide details of future upgrades to the experimental apparatus and discuss interesting potential for using holmium in quantum computing using single atoms in a magnetically trapped lattice. This thesis shows several promising indicators for continued work in this field.

  11. Proposed magneto-electrostatic ring trap for neutral atoms

    CERN Document Server

    Hopkins, A; Mabuchi, H; Hopkins, Asa; Lev, Benjamin; Mabuchi, Hideo

    2004-01-01

    We propose a novel trap for confining cold neutral atoms in a ring using a magneto-electrostatic potential. The trapping potential is derived from a combination of a repulsive magnetic field from a hard drive atom mirror and the attractive potential produced by a charged disk patterned on the hard drive surface. We calculate a trap frequency of [29.8, 42.8, 63.1] kHz and a depth of [16.3, 21.6, 21.6] MHz for [133Cs, 87Rb, 40K], and discuss a simple loading scheme and a method for fabrication. This device provides a one-dimensional potential in a ring geometry that may be of interest to the study of trapped quantum degenerate one-dimensional gases.

  12. Atomic physics experiments with trapped and cooled highly charged ions

    OpenAIRE

    Kluge, H.-J.; Quint, W; Winters, D. F. A

    2007-01-01

    Trapping and cooling techniques have become very important for many fundamental experiments in atomic physics. When applied to highly charged ions confined in Penning traps, these procedures are very effective for testing quantum electrodynamics in extreme electromagnetic fields produced by heavy highly charged ions such as uranium U$^{91+}$. In addition, fundamental constants or nuclear ground state properties can be determined with high accuracy in these simple systems. Finally, by studying...

  13. Dark Optical Lattice of Ring Traps for Cold Atoms

    CERN Document Server

    Courtade, E; Houde, O; Verkerk, P; Courtade, Emmanuel; Hennequin, Daniel; Houde, Olivier; Verkerk, Philippe

    2006-01-01

    We propose a new geometry of optical lattice for cold atoms, namely a lattice made of a 1D stack of dark ring traps. It is obtained through the interference pattern of a standard Gaussian beam with a counter-propagating hollow beam obtained using a setup with two conical lenses. The traps of the resulting lattice are characterized by a high confinement and a filling rate much larger than unity, even if loaded with cold atoms from a MOT. We have implemented this system experimentally, and obtained a lattice of ring traps populated with typically 40 atoms per site with a life time of 30 ms. Applications in statistical physics, quantum computing and Bose-Einstein condensate dynamics are conceivable.

  14. Resonant quantum transitions in trapped antihydrogen atoms

    CERN Document Server

    Amole, C; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Donnan, P H; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Shields, C R; Silveira, D M; Stracka, S; So, C; Thompson, R I; van der Werf, D P; Wurtele, J S

    2012-01-01

    The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom’s stature lies in its simplicity and in the accuracy with which its spectrum can be measured1 and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and—by comparison with measurements on its antimatter counterpart, antihydrogen—the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state2, 3 of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave...

  15. Bichromatic State-insensitive Trapping of Caesium Atoms

    CERN Document Server

    Metbulut, M M

    2015-01-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of l...

  16. Bichromatic state-insensitive trapping of caesium atoms

    Science.gov (United States)

    Metbulut, M. M.; Renzoni, F.

    2015-12-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of laser wavelengths corresponding to currently available high power lasers. These wavelength pairs were found to be in the range of 585-588 nm and 623-629 for one laser and 1064-1080 nm for the other.

  17. Resonator-Enhanced Optical Dipole Trap for Fermionic Lithium Atoms

    CERN Document Server

    Mosk, A P; Moritz, H; Elsaesser, T; Weidemüller, M; Grimm, R; Elsaesser, Th.

    2001-01-01

    We demonstrate a novel optical dipole trap which is based on the enhancement of the optical power density of a Nd:YAG laser beam in a resonator. The trap is particularly suited for experiments with ultracold gases, as it combines a potential depth of order 1 mK with storage times of several tens of seconds. We study the interactions in a gas of fermionic lithium atoms in our trap and observe the influence of spin-changing collisions and off-resonant photon scattering. A key element in reaching long storage times is an ultra-low noise laser. The dependence of the storage time on laser noise is investigated.

  18. Resonator-Enhanced Optical Dipole Trap for Fermionic Lithium Atoms

    OpenAIRE

    Mosk, A.; Jochim, S.; Moritz, H.; Elsaesser, Th.; Weidemueller, M.; Grimm, R

    2001-01-01

    We demonstrate a novel optical dipole trap which is based on the enhancement of the optical power density of a Nd:YAG laser beam in a resonator. The trap is particularly suited for experiments with ultracold gases, as it combines a potential depth of order 1 mK with storage times of several tens of seconds. We study the interactions in a gas of fermionic lithium atoms in our trap and observe the influence of spin-changing collisions and off-resonant photon scattering. A key element in reachin...

  19. Cold atoms in microscopic traps from wires to chips

    CERN Document Server

    Cassettari, D

    2000-01-01

    Ioffe-Pritchard trap. In the latter we have achieved the trapping parameters required in the experiments with Bose-Einstein condensates with much reduced power consumption. In a second time we have replaced the free standing wires with an atom chip, which we have used to compress the atomic cloud in potentials with trap frequencies above 100 kHz and ground state sizes below 100 nm. Such potentials are especially interesting for quantum information proposals of performing quantum gate operations with controlled collisions between trapped atoms. Finally, by combining two wire guides we have experimentally realized an innovative kind of beam splitter for guided atoms. We have investigated the splitting potential generated by a Y-shaped wire which has one input, i.e. the central arm of the Y, and two outputs corresponding to the left and right arms of the Y. By tuning the current ratio in the two outputs we have observed atoms switching from left to right as well as symmetric splitting. This and other similar des...

  20. Trapping of Single Atoms with Single Photons in Cavity QED

    CERN Document Server

    Doherty, A C; Hood, C J; Kimble, H J

    2000-01-01

    Two recent experiments have reported the trapping of individual atoms inside optical resonators by the mechanical forces associated with single photons [Hood et al., Science 287, 1447 (2000) and Pinkse et al., Nature 404, 365 (2000)]. Here we analyze the trapping dynamics in these settings, focusing on two points of interest. Firstly, we investigate the extent to which light-induced forces in these experiments are distinct from their free-space counterparts. Secondly, we explore the quantitative features of the resulting atomic motion and how these dynamics are mapped onto variations of the intracavity field. Not surprisingly, qualitatively distinct atomic dynamics arise as the coupling and dissipative rates are varied. For the experiment of Hood et al., we show that atomic motion is largely conservative and is predominantly in radial orbits transverse to the cavity axis. A comparison with the free-space theory demonstrates that the fluctuations of the dipole force are suppressed by an order of magnitude. Thi...

  1. A dynamic magneto-optical trap for atom chips

    CERN Document Server

    Rushton, Jo; Bateman, James; Himsworth, Matt

    2016-01-01

    We describe a dynamic magneto-optical trap (MOT) suitable for the use with vacuum systems in which optical access is limited to a single window. This technique facilitates the long-standing desire of producing integrated atom chips, many of which are likely to have severely restricted optical access compared with conventional vacuum chambers. This "switching-MOT" relies on the synchronized pulsing of optical and magnetic fields at audio frequencies. The trap's beam geometry is obtained using a planar mirror surface, and does not require a patterned substrate or bulky optics inside the vacuum chamber. Central to the design is a novel magnetic field geometry that requires no external quadrupole or bias coils which leads toward a very compact system. We have implemented the trap for $^{85}$Rb and shown that it is capable of capturing 2 million atoms and directly cooling below the Doppler temperature.

  2. An architecture for quantum computation with magnetically trapped Holmium atoms

    Science.gov (United States)

    Saffman, Mark; Hostetter, James; Booth, Donald; Collett, Jeffrey

    2016-05-01

    Outstanding challenges for scalable neutral atom quantum computation include correction of atom loss due to collisions with untrapped background gas, reduction of crosstalk during state preparation and measurement due to scattering of near resonant light, and the need to improve quantum gate fidelity. We present a scalable architecture based on loading single Holmium atoms into an array of Ioffe-Pritchard traps. The traps are formed by grids of superconducting wires giving a trap array with 40 μm period, suitable for entanglement via long range Rydberg gates. The states | F = 5 , M = 5 > and | F = 7 , M = 7 > provide a magic trapping condition at a low field of 3.5 G for long coherence time qubit encoding. The F = 11 level will be used for state preparation and measurement. The availability of different states for encoding, gate operations, and measurement, spectroscopically isolates the different operations and will prevent crosstalk to neighboring qubits. Operation in a cryogenic environment with ultra low pressure will increase atom lifetime and Rydberg gate fidelity by reduction of blackbody induced Rydberg decay. We will present a complete description of the architecture including estimates of achievable performance metrics. Work supported by NSF award PHY-1404357.

  3. Ultratrace determination of tin by hydride generation in-atomizer trapping atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Průša, Libor [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Hlavova 8, Prague 2, CZ 128 43 Czech Republic (Czech Republic); Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

    2013-12-04

    Graphical abstract: -- Highlights: •In-atomizer trapping HG-AAS was optimized for Sn. •A compact quartz trap-and-atomizer device was employed. •Generation, preconcentration and atomization steps were investigated in detail. •Hundred percent preconcentration efficiency for tin was reached. •Routine analytical method was developed for Sn determination (LOD of 0.03 ng mL{sup −1} Sn). -- Abstract: A quartz multiatomizer with its inlet arm modified to serve as a trap (trap-and-atomizer device) was employed to trap tin hydride and subsequently to volatilize collected analyte species with atomic absorption spectrometric detection. Generation, atomization and preconcentration conditions were optimized and analytical figures of merit of both on-line atomization as well as preconcentration modes were quantified. Preconcentration efficiency of 95 ± 5% was found. The detection limits reached were 0.029 and 0.14 ng mL{sup −1} Sn, respectively, for 120 s preconcentration period and on-line atomization mode without any preconcentration. The interference extent of other hydride forming elements (As, Se, Sb and Bi) on tin determination was found negligible in both modes of operation. The applicability of the developed preconcentration method was verified by Sn determination in a certified reference material as well as by analysis of real samples.

  4. Harmonic trap resonance enhanced synthetic atomic spin-orbit coupling

    Science.gov (United States)

    Wu, Ling-Na; Luo, Xinyu; Xu, Zhi-Fang; Ueda, Masahito; Wang, Ruquan; You, Li

    2016-05-01

    The widely adopted scheme for synthetic atomic spin-orbit coupling (SOC) is based on the momentum sensitive Raman coupling, which is easily implemented in one spatial dimension. Recently, schemes based on pulsed or periodically modulating gradient magnetic field (GMF) were proposed and the main characteristic features have subsequently been demonstrated. The present work reports an experimental discovery and the associated theoretical understanding of tuning the SOC strength synthesized with GMF through the motional resonance of atomic center-of-mass in a harmonic trap. In some limits, we observe up to 10 times stronger SOC compared to the momentum impulse from GMF for atoms in free space.

  5. Large amplitude spin oscillations in a collisionless trapped atomic gas

    CERN Document Server

    Piechon, F; Laloë, F

    2009-01-01

    We propose an explanation of the recently observed strong spin segregation in a trapped Fermi gas by Du et al. Numerical and analytical solutions of a spin 1/2 kinetic equation in a collisionless regime explain quantitatively the observation of an "anomalous" large time scale and amplitude of the segregation. The key difference with previous experiment on bosons rests more in the diluteness of the gas than in the quantum statistics of the atoms. When they undergo fast ballistic oscillations in the trap, they average the inhomogeneous external field in an energy dependent way, so that their transverse spin precession frequency becomes proportional to their energy. Interactions between atoms of different energies and different spin directions then involve the identical spin rotation effect (ISRE), which transfers atoms to the up or down spin state in an energy dependent way. Since low energy atoms are closer to the center of the trap than high energy atoms, which can visit its edges, the final outcome is a stro...

  6. Coherence Properties of Nanofiber-Trapped Cesium Atoms

    Science.gov (United States)

    Reitz, D.; Sayrin, C.; Mitsch, R.; Schneeweiss, P.; Rauschenbeutel, A.

    2013-06-01

    We experimentally study the ground state coherence properties of cesium atoms in a nanofiber-based two-color dipole trap, localized ˜200nm away from the fiber surface. Using microwave radiation to coherently drive the clock transition, we record Ramsey fringes as well as spin echo signals and infer a reversible dephasing time of T2*=0.6ms and an irreversible dephasing time of T2'=3.7ms. By modeling the signals, we find that, for our experimental parameters, T2* and T2' are limited by the finite initial temperature of the atomic ensemble and the heating rate, respectively. Our results represent a fundamental step towards establishing nanofiber-based traps for cold atoms as a building block in an optical fiber quantum network.

  7. Optical dipole trapping of radium atoms for EDM search

    Science.gov (United States)

    Trimble, W. L.; Sulai, I. A.; Parker, R. H.; Bailey, K.; Greene, J. P.; Holt, R. J.; Korsch, W.; Lu, Z.-T.; Mueller, P.; O'Connor, T. P.; Singh, J.

    2010-03-01

    We are developing an EDM search based on laser-cooled and trapped Ra-225 (half-life = 15 d) atoms. Due to octupole deformation of the nucleus, Ra-225 is predicted to be 2-3 orders of magnitude more sensitive to T-violating interactions than Hg-199, which currently sets the most stringent limits in the nuclear sector. Recently, we have succeeded in transferring Ra-226 atoms from a MOT into an optical dipole trap formed by a fiber laser beam at 1550 nm. For the EDM measurement, the cold atoms will be moved into the neighboring vacuum chamber inside magnetic shields where a pair of electrodes apply a 10 kV cm-1electric field. This work is supported by DOE, Office of Nuclear Physics under contract No. DE-AC02-06CH11357.

  8. Coherence properties of nanofiber-trapped cesium atoms

    CERN Document Server

    Reitz, D; Mitsch, R; Schneeweiss, P; Rauschenbeutel, A

    2013-01-01

    We experimentally study the ground state coherence properties of cesium atoms in a nanofiber-based two-color dipole trap, localized 200 nm away from the fiber surface. Using microwave radiation to coherently drive the clock transition, we record Ramsey fringes as well as spin echo signals and infer a reversible dephasing time $T_2^\\ast=0.6$ ms and an irreversible dephasing time $T_2^\\prime=3.7$ ms. By theoretically modelling the signals, we find that, for our experimental parameters, $T_2^\\ast$ and $T_2^\\prime$ are limited by the finite initial temperature of the atomic ensemble and the heating rate, respectively. Our results represent a fundamental step towards establishing nanofiber-based traps for cold atoms as a building block in an optical fiber quantum network.

  9. Arrays of microscopic magnetic traps for cold atoms and their applications in atom optics

    Institute of Scientific and Technical Information of China (English)

    印建平; 高伟建; 胡建军

    2002-01-01

    A single microscopic magnetic trap for neutral atoms using planar current-carrying wires was proposed and studiedtheoretically by Weinstein et al. In this paper, we propose three structures of composite current-carrying wires to provide1D, 2D and 3D arrays of microscopic magnetic traps for cold alkali atoms. The spatial distributions of magnetic fieldsgenerated by these structures are calculated and the field gradient and curvature in each single microtrap are analysed.Our study shows that arrays of microscopic magnetic traps can be used to provide 1D, 2D or 3D atomic magneticlattices, and even to realize 1D, 2D and 3D arrays of magneto-optical traps, and so on.

  10. Atomic physics experiments with trapped and cooled highly charged ions

    CERN Document Server

    Kluge, H -J; Winters, D F A

    2007-01-01

    Trapping and cooling techniques have become very important for many fundamental experiments in atomic physics. When applied to highly charged ions confined in Penning traps, these procedures are very effective for testing quantum electrodynamics in extreme electromagnetic fields produced by heavy highly charged ions such as uranium U$^{91+}$. In addition, fundamental constants or nuclear ground state properties can be determined with high accuracy in these simple systems. Finally, by studying a single trapped radioactive ion, its nuclear decay can be studied in detail by observing the disappearance of the signal of the mother and the appearance of that of the daughter isotope. Such experiments on highly charged ions at extremely low energy will become possible by the HITRAP facility which is currently being built up at GSI. Also the future Facility for Antiproton and Ion Research (FAIR) will be briefly described which is expected to be operational by 2014.

  11. Extremely nonlocal optical nonlinearities in atoms trapped near a waveguide

    CERN Document Server

    Shahmoon, Ephraim; Stimming, Hans Peter; Mazets, Igor; Kurizki, Gershon

    2014-01-01

    Nonlinear optical phenomena are typically local. Here we predict the possibility of highly nonlocal optical nonlinearities for light propagating in atomic media trapped near a nano-waveguide, where long-range interactions between the atoms can be tailored. When the atoms are in an electromagnetically-induced transparency configuration, the atomic interactions are translated to long-range interactions between photons and thus to highly nonlocal optical nonlinearities. We derive and analyze the governing nonlinear propagation equation, finding a roton-like excitation spectrum for light and the emergence of long-range order in its output intensity. These predictions open the door to studies of unexplored wave dynamics and many-body physics with highly-nonlocal interactions of optical fields in one dimension.

  12. Highly nonlocal optical nonlinearities in atoms trapped near a waveguide

    Science.gov (United States)

    Shahmoon, Ephraim; Grisins, Pjotrs; Stimming, Hans Peter; Mazets, Igor; Kurizki, Gershon

    2016-05-01

    Nonlinear optical phenomena are typically local. Here we predict the possibility of highly nonlocal optical nonlinearities for light propagating in atomic media trapped near a nano-waveguide, where long-range interactions between the atoms can be tailored. When the atoms are in an electromagnetically-induced transparency configuration, the atomic interactions are translated to long-range interactions between photons and thus to highly nonlocal optical nonlinearities. We derive and analyze the governing nonlinear propagation equation, finding a roton-like excitation spectrum for light and the emergence of long-range order in its output intensity. These predictions open the door to studies of unexplored wave dynamics and many-body physics with highly-nonlocal interactions of optical fields in one dimension.

  13. Coherent Population Trapping-Ramsey Interference in Cold Atoms

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi; YANG Guo-Qing; WANG Jin; ZHAN Ming-Sheng

    2010-01-01

    @@ We demonstrate an experimental observation of coherent population trapping-Ramsey interference in cold 87Rb atoms by employing the time-domain separated oscillatory fields' method. The interference fringe with line width of 80Hz is obtained. We propose a novel method to measure the cold atom number. The measurement is insensitive to the pump beam intensity, the single photon detuning and even the initial state population. We use this method to normalize the interference signal and to improve the signal-to-noise ratio significantly.

  14. High contrast atomic magnetometer based on coherent population trapping

    International Nuclear Information System (INIS)

    We present an experimental and theoretical investigation of the coherent population trapping (CPT) resonance excited on the D1 line of 87Rb atoms by bichromatic linearly polarized laser light. The experimental results show that a lin ‖ lin transition scheme is a promising alternative to the conventional circular—circular transition scheme for an atomic magnetometer. Compared with the circular light transition scheme, linear light accounts for high-contrast transmission resonances, which makes this excitation scheme promising for high-sensitivity magnetometers. We also use linear light and circular light to detect changes of a standard magnetic field, separately. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  15. Spin diffusion in trapped clouds of strongly interacting cold atoms

    OpenAIRE

    Bruun, G. M.; Pethick, C.J.

    2011-01-01

    We show that puzzling recent experimental results on spin diffusion in a strongly interacting atomic gas may be understood in terms of the predicted spin diffusion coefficient for a generic strongly interacting system. Three important features play a central role: a) Fick's law for diffusion must be modified to allow for the trapping potential, b) the diffusion coefficient is inhomogeneous, due to the density variations in the cloud and c) the diffusion approximation fails in the outer parts ...

  16. Atom trapping in a bottle beam created by a diffractive optical element

    CERN Document Server

    Ivanov, V V; Saffman, M; Kemme, S A; Ellis, A R; Brady, G R; Wendt, J R; Biedermann, G W; Samora, S

    2013-01-01

    A diffractive optical element (DOE) has been fabricated for creating blue detuned atomic bottle beam traps. The DOE integrates several diffractive lenses for trap creation and imaging of atomic fluorescence. We characterize the performance of the DOE and demonstrate trapping of cold Cesium atoms inside a bottle beam.

  17. Effects of the Centre-of-Mass Motion on the Population Trapping of Ultracold Atoms

    Institute of Scientific and Technical Information of China (English)

    熊锦; 张智明

    2003-01-01

    We investigate the effects of the atomic centre-of-mass motion on atomic population trapping in a two-mode micromaser injected with ultracold A-type three-level atoms.We find that in the mazer regime(the case in which the atomic kinetic energy is much smaller than the atom-field interaction energy),the interplay between reflection and transmission of the ultracold atom leads to the destruction of the atomic population trapping.

  18. Adjustable microchip ring trap for cold atoms and molecules

    CERN Document Server

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

    2009-01-01

    We describe the design and function of a circular magnetic waveguide for deBroglie waves produced from wires on a microchip. 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.

  19. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping

    Energy Technology Data Exchange (ETDEWEB)

    Jones, John; Xiong, Haifeng; DelaRiva, Andrew; Peterson, Eric J.; Pham, Hien; Challa, Sivakumar R.; Qi, Gongshin; Oh, Se H.; Wiebenga, Michelle H.; Pereira Hernandez, Xavier I.; Wang, Yong; Datye, Abhaya K.

    2016-07-08

    Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/ aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.

  20. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping.

    Science.gov (United States)

    Jones, John; Xiong, Haifeng; DeLaRiva, Andrew T; Peterson, Eric J; Pham, Hien; Challa, Sivakumar R; Qi, Gongshin; Oh, Se; Wiebenga, Michelle H; Pereira Hernández, Xavier Isidro; Wang, Yong; Datye, Abhaya K

    2016-07-01

    Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst. PMID:27387946

  1. Portable atomic frequency standard based on coherent population trapping

    Science.gov (United States)

    Shi, Fan; Yang, Renfu; Nian, Feng; Zhang, Zhenwei; Cui, Yongshun; Zhao, Huan; Wang, Nuanrang; Feng, Keming

    2015-05-01

    In this work, a portable atomic frequency standard based on coherent population trapping is designed and demonstrated. To achieve a portable prototype, in the system, a single transverse mode 795nm VCSEL modulated by a 3.4GHz RF source is used as a pump laser which generates coherent light fields. The pump beams pass through a vapor cell containing atom gas and buffer gas. This vapor cell is surrounded by a magnetic shield and placed inside a solenoid which applies a longitudinal magnetic field to lift the Zeeman energy levels' degeneracy and to separate the resonance signal, which has no first-order magnetic field dependence, from the field-dependent resonances. The electrical control system comprises two control loops. The first one locks the laser wavelength to the minimum of the absorption spectrum; the second one locks the modulation frequency and output standard frequency. Furthermore, we designed the micro physical package and realized the locking of a coherent population trapping atomic frequency standard portable prototype successfully. The short-term frequency stability of the whole system is measured to be 6×10-11 for averaging times of 1s, and reaches 5×10-12 at an averaging time of 1000s.

  2. Stability of a trapped atom clock on a chip

    CERN Document Server

    Szmuk, Ramon; Maineult, Wilfried; Reichel, Jakob; Rosenbusch, Peter

    2015-01-01

    We present a compact atomic clock interrogating ultracold 87Rb magnetically trapped on an atom chip. Very long coherence times sustained by spin self-rephasing allow us to interrogate the atomic transition with 85% contrast at 5 s Ramsey time. The clock exhibits a fractional frequency stability of $5.8\\times 10^{-13}$ at 1 s and is likely to integrate into the $1\\times10^{-15}$ range in less than a day. A detailed analysis of 7 noise sources explains the measured frequency stability. Fluctuations in the atom temperature (0.4 nK shot-to-shot) and in the offset magnetic field ($5\\times10^{-6}$ relative fluctuations shot-to-shot) are the main noise sources together with the local oscillator, which is degraded by the 30% duty cycle. The analysis suggests technical improvements to be implemented in a future second generation set-up. The results demonstrate the remarkable degree of technical control that can be reached in an atom chip experiment.

  3. Coherent population trapping in a Raman atom interferometer

    CERN Document Server

    Cheng, Bing; Merlet, Sébastien; Santos, Franck Pereira dos

    2016-01-01

    We investigate the effect of coherent population trapping (CPT) in an atom inter-ferometer gravimeter based on the use of stimulated Raman transitions. We find that CPT leads to significant phase shifts, of order of a few mrad, which may compromise the accuracy of inertial measurements. We show that this effect is rejected by the k-reversal technique, which consists in averaging inertial measurements performed with two opposite orientations of the Raman wavevector k, provided that internal states at the input of the interferometer are kept identical for both configurations.

  4. Rapid Cooling to Quantum Degeneracy with Dynamically Shaped Atom Traps

    CERN Document Server

    Roy, Richard; Bowler, Ryan; Gupta, Subhadeep

    2016-01-01

    We report on a general method for the rapid production of quantum degenerate gases. Using 174Yb, we achieve an experimental cycle time as low as (1.6-1.8) s for the production of Bose-Einstein condensates (BECs) of (0.5-1) x 10^5 atoms. While laser cooling to 30\\muK proceeds in a standard way, evaporative cooling is highly optimized by performing it in an optical trap that is dynamically shaped by utilizing the time-averaged potential of a single laser beam moving rapidly in one dimension. We also produce large (>10^6) atom number BECs and successfully model the evaporation dynamics over more than three orders of magnitude in phase space density. Our method provides a simple and general approach to solving the problem of long production times of quantum degenerate gases.

  5. Trapping and cooling cesium atoms in a speckle field

    International Nuclear Information System (INIS)

    We present the results of two experiments where cold cesium atoms are trapped in a speckle field. In the first experiment, a YAG laser creates the speckle pattern and induces a far-detuned dipole potential which is a nearly-conservative potential. Localization of atoms near the intensity maxima of the speckle field is observed. In a second experiment we use two counterpropagating laser beams tuned close to a resonance line of cesium and in the lin perpendicular to lin configuration, one of them being modulated by a holographic diffuser that creates the speckle field. Three-dimensional cooling is observed. Variations of the temperature and of the spatial diffusion coefficient with the size of a speckle grain are presented. (orig.)

  6. Magneto-optical trap for neutral mercury atoms

    Institute of Scientific and Technical Information of China (English)

    Liu Hong-Li; Yin Shi-Qi; Liu Kang-Kang; Qian Jun; Xu Zhen; Hong Tao; Wang Yu-Zhu

    2013-01-01

    Due to its low sensitivity to blackbody radiation,neutral mercury is a good candidate for the most accurate optical lattice clock.Here we report the observation of cold mercury atoms in a magneto-optical trap (MOT).Because of the high vapor pressure at room temperature,the mercury source and the cold pump were cooled down to-40 ℃ and-70 ℃,respectively,to keep the science chamber in an ultra-high vacuum of 6× 10-9 Pa.Limited by the power of the UV cooling laser,the one beam folded MOT configuration was adopted,and 1.5× 105 Hg-202 atoms were observed by fluorescence detection.

  7. Resonance fluorescence of a trapped three-level atom

    CERN Document Server

    Bienert, M; Morigi, G; Bienert, Marc; Merkel, Wolfgang; Morigi, Giovanna

    2003-01-01

    We investigate theoretically the spectrum of resonance fluorescence of a harmonically trapped atom, whose internal transitions are $\\Lambda$--shaped and driven at two-photon resonance by a pair of lasers, which cool the center--of--mass motion. For this configuration, photons are scattered only due to the mechanical effects of the quantum interaction between light and atom. We study the spectrum of emission in the final stage of laser--cooling, when the atomic center-of-mass dynamics is quantum mechanical and the size of the wave packet is much smaller than the laser wavelength (Lamb--Dicke limit). We use the spectral decomposition of the Liouville operator of the master equation for the atomic density matrix and apply second order perturbation theory. We find that the spectrum of resonance fluorescence is composed by two narrow sidebands -- the Stokes and anti-Stokes components of the scattered light -- while all other signals are in general orders of magnitude smaller. For very low temperatures, however, th...

  8. Holographic optical traps for atom-based topological Kondo devices

    Science.gov (United States)

    Buccheri, F.; Bruce, G. D.; Trombettoni, A.; Cassettari, D.; Babujian, H.; Korepin, V. E.; Sodano, P.

    2016-07-01

    The topological Kondo (TK) model has been proposed in solid-state quantum devices as a way to realize non-Fermi liquid behaviors in a controllable setting. Another motivation behind the TK model proposal is the demand to demonstrate the quantum dynamical properties of Majorana fermions, which are at the heart of their potential use in topological quantum computation. Here we consider a junction of crossed Tonks-Girardeau gases arranged in a star-geometry (forming a Y-junction), and we perform a theoretical analysis of this system showing that it provides a physical realization of the TK model in the realm of cold atom systems. Using computer-generated holography, we experimentally implement a Y-junction suitable for atom trapping, with controllable and independent parameters. The junction and the transverse size of the atom waveguides are of the order of 5 μm, leading to favorable estimates for the Kondo temperature and for the coupling across the junction. Since our results show that all the required theoretical and experimental ingredients are available, this provides the demonstration of an ultracold atom device that may in principle exhibit the TK effect.

  9. A Compact Microchip-Based Atomic Clock Based on Ultracold Trapped Rb Atoms

    CERN Document Server

    Farkas, Daniel M; Anderson, Dana Z

    2009-01-01

    We propose a compact atomic clock based on ultracold Rb atoms that are magnetically trapped near the surface of an atom microchip. An interrogation scheme that combines electromagnetically-induced transparency (EIT) with Ramsey's method of separated oscillatory fields can achieve atomic shot-noise level performance of 10^{-13}/sqrt(tau) for 10^6 atoms. The EIT signal can be detected with a heterodyne technique that provides noiseless gain; with this technique the optical phase shift of a 100 pW probe beam can be detected at the photon shot-noise level. Numerical calculations of the density matrix equations are used to identify realistic operating parameters at which AC Stark shifts are eliminated. By considering fluctuations in these parameters, we estimate that AC Stark shifts can be canceled to a level better than 2*10^{-14}. An overview of the apparatus is presented with estimates of duty cycle and power consumption.

  10. Development of a compact cold-atom atomic clock based on coherent population trapping

    Science.gov (United States)

    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.

  11. Box traps on an atom chip for one-dimensional quantum gases

    CERN Document Server

    van Es, J J P; van Amerongen, A H; Rétif, C; Whitlock, S; van Druten, N J

    2009-01-01

    We present the implementation of tailored trapping potentials for ultracold gases on an atom chip. We realize highly elongated traps with box-like confinement along the long, axial direction combined with conventional harmonic confinement along the two radial directions. The design, fabrication and characterization of the atom chip and the box traps is described. We load ultracold ($\\lesssim1 \\mu$K) clouds of $^{87}$Rb in a box trap, and demonstrate Bose-gas focusing as a means to characterize these atomic clouds in arbitrarily shaped potentials. Our results show that box-like axial potentials on atom chips are very promising for studies of one-dimensional quantum gases.

  12. Observation of cooperatively enhanced atomic dipole forces from NV centers in optically trapped nanodiamonds

    CERN Document Server

    Juan, M L; Besga, B; Brennen, G; Molina-Terriza, G; Volz, T

    2015-01-01

    Since the early work by Ashkin in 1970, optical trapping has become one of the most powerful tools for manipulating small particles, such as micron sized beads or single atoms. The optical trapping mechanism is based on the interaction energy of a dipole and the electric field of the laser light. In atom trapping, the dominant contribution typically comes from the allowed optical transition closest to the laser wavelength, whereas for mesoscopic particles it is given by the bulk polarizability of the material. These two different regimes of optical trapping have coexisted for decades without any direct link, resulting in two very different contexts of applications: one being the trapping of small objects mainly in biological settings, the other one being dipole traps for individual neutral atoms in the field of quantum optics. Here we show that for nanoscale diamond crystals containing artificial atoms, so-called nitrogen vacancy (NV) color centers, both regimes of optical trapping can be observed at the same...

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

    Science.gov (United States)

    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.

  14. Accumulation and thermalization of cold atoms in a finite-depth magnetic trap

    CERN Document Server

    Chicireanu, R; Gorceix, O; Keller, J C; Laburthe-Tolra, B; Marechal, E; Porto, J V; Pouderous, A; Vernac, L

    2006-01-01

    We experimentally and theoretically study the continuous accumulation of cold atoms from a magneto-optical trap (MOT) into a finite depth trap, consisting in a magnetic quadrupole trap dressed by a radiofrequency (RF) field. Chromium atoms (52 isotope) in a MOT are continuously optically pumped by the MOT lasers to metastable dark states. In presence of a RF field, the temperature of the metastable atoms that remain magnetically trapped can be as low as 25 microK, with a density of 10^17 atoms.m-3, resulting in an increase of the phase-space density, still limited to 7.10^-6 by inelastic collisions. To investigate the thermalization issues in the truncated trap, we measure the free evaporation rate in the RF-truncated magnetic trap, and deduce the average elastic cross section for atoms in the 5D4 metastable states, equal to 7.0 10^-16m2.

  15. Integrated Optical Dipole Trap for Cold Neutral Atoms with an Optical Waveguide Coupler

    CERN Document Server

    Lee, J; Mittal, S; Dagenais, M; Rolston, S L

    2013-01-01

    An integrated optical dipole trap uses two-color (red and blue-detuned) traveling evanescent wave fields for trapping cold neutral atoms. To achieve longitudinal confinement, we propose using an integrated optical waveguide coupler, which provides a potential gradient along the beam propagation direction sufficient to confine atoms. This integrated optical dipole trap can support an atomic ensemble with a large optical depth due to its small mode area. Its quasi-TE0 waveguide mode has an advantage over the HE11 mode of a nanofiber, with little inhomogeneous Zeeman broadening at the trapping region. The longitudinal confinement eliminates the need for a 1-D optical lattice, reducing collisional blockaded atomic loading, potentially producing larger ensembles. The waveguide trap allows for scalability and integrability with nano-fabrication technology. We analyze the potential performance of such integrated atom traps.

  16. Highly uniform holographic microtrap arrays for single atom trapping using a feedback optimization of in-trap fluorescence measurements.

    Science.gov (United States)

    Tamura, Hikaru; Unakami, Tomoyuki; He, Jun; Miyamoto, Yoko; Nakagawa, Ken'ichi

    2016-04-18

    We report on the novel optimization method to realize highly uniform microtrap arrays for single atom trapping with a spatial light modulator (SLM). This method consists of two iterative feedback loops with the measurements of both diffracted light intensities and in-trap fluorescence intensities from each microtrap. By applying this method to the single 87Rb atom trapping, we can reduce the variance of trap depths from 20.8% to 1.7% for 4 × 4 square arrays and less than 4% for various arrays with up to 62 sites. The detection error of individual single atoms is also reduced from 1.7% to 0.0054% on average. PMID:27137252

  17. Fast thermometry for trapped atoms using recoil-induced resonance

    Science.gov (United States)

    Zhao, Yan-Ting; Su, Dian-Qiang; Ji, Zhong-Hua; Zhang, Hong-Shan; Xiao, Lian-Tuan; Jia, Suo-Tang

    2015-09-01

    We have employed recoil-induced resonance (RIR) with linewidth on the order of 10 kHz to demonstrate the fast thermometry for ultracold atoms. We theoretically calculate the absorption spectrum of RIR which agrees well with the experimental results. The temperature of the ultracold sample derived from the RIR spectrum is T = 84±4.5 μK, which is close to 85 μK that measured by the method of time-of-flight absorption imaging. To exhibit the fast measurement advantage in applying RIR to the ultracold atom thermometry, we study the dependence of ultracold sample temperature on the trapping beam frequency detuning. This method can be applied to determine the translational temperature of molecules in photoassociation dynamics. Project supported by the National Basic Research Development Program of China (Grant No. 2012CB921603), the National High Technology Research and Development Program of China (Grant No. 2011AA010801), the National Natural Science Foundation of China (Grant Nos. 61275209, 11304189, 61378015, and 11434007), and Program for Changjiang Scholars and Innovative Research Team in Universities of China (Grant No. IRT13076).

  18. A two-dimensional lattice of blue detuned atom traps using a projected Gaussian beam array

    CERN Document Server

    Piotrowicz, M J; Maller, K; Li, G; Zhang, S; Isenhower, L; Saffman, M

    2013-01-01

    We describe a new type of blue detuned optical lattice for atom trapping which is intrinsically two dimensional, while providing three-dimensional atom localization. The lattice is insensitive to optical phase fluctuations since it does not depend on field interference between distinct optical beams. The array is created using a novel arrangement of weakly overlapping Gaussian beams that creates a two-dimensional array of dark traps which are suitable for magic trapping of ground and Rydberg states. We analyze the spatial localization that can be achieved and demonstrate trapping and detection of single Cs atoms in 6 and 49 site two-dimensional arrays.

  19. Bichromatic state-insensitive trapping of cold133Cs-87Rb atomic mixtures

    Science.gov (United States)

    Metbulut, M. M.; Renzoni, F.

    2015-12-01

    We investigate simultaneous state-insensitive trapping of a mixture of two different atomic species, Caesium and Rubidium. The magic wavelengths of the Caesium and Rubidium atoms are different, $935.6$ nm and $789.9$ nm respectively, thus single-frequency simultaneous state-insensitive trapping is not possible. We thus identify bichromatic trapping as a viable approach to tune the two magic wavelengths to a common value. Correspondingly, we present several common magic wavelength combinations appropriate for simultaneous state-insensitive trapping of the two atomic species.

  20. 3D modeling of magnetic atom traps on type-II superconductor chips

    International Nuclear Information System (INIS)

    Magnetic traps for cold atoms have become a powerful tool in cold atom physics and condensed matter research. The traps on superconducting chips allow one to increase the trapped atom lifetime and coherence time by decreasing the thermal noise by several orders of magnitude compared to that of the typical normal-metal conductors. A thin superconducting film in the mixed state is, usually, the main element of such a chip. Using a finite element method to analyze thin film magnetization and transport current in type-II superconductivity, we study magnetic traps recently employed in experiments. The proposed approach allows us to predict important characteristics of the magnetic traps (their depth, shape, distance from the chip surface, etc) that are necessary when designing magnetic traps in cold atom experiments. (paper)

  1. Inhomogeneous broadening of optical transitions of 87Rb atoms in an optical nanofiber trap

    CERN Document Server

    Lee, J; Hoffman, J E; Orozco, L A; Rolston, S L

    2014-01-01

    We experimentally demonstrate optical trapping of 87Rb atoms using a two-color evanescent field around an optical nanofiber. In our trapping geometry, a blue-detuned traveling wave whose polarization is nearly parallel to the polarization of a red-detuned standing wave produce significant vector light shifts that lead to broadening of the absorption profile of a near-resonant beam at the trapping site. A model that includes scalar, vector, and tensor light shifts of the probe transition $5S_{1/2}$-$5P_{3/2}$ from the trapping beams; weighted by the temperature-dependent position of the atoms in the trap qualitatively describe the observed asymmetric profile, and explained differences with previous experiments that used Cs atoms. The model provides a consistent way to extract the number of atoms in the trap.

  2. Collisional cooling of light ions by co-trapped heavy atoms

    CERN Document Server

    Dutta, Sourav; Rangwala, S A

    2015-01-01

    The most generic cooling and thermalization pathway at the lowest temperatures is via elastic collisions. In hybrid ion-atom traps, ion cooling to temperatures where low partial wave collisions dominate require the collisional cooling mechanism to be well understood and controlled. There exists great uncertainty on whether cooling of light ions by heavier neutral atoms is possible. Here we experimentally demonstrate the cooling of light ions by co-trapped heavy atoms for the first time. We show that trapped 39K+ ions are cooled by localized ultracold neutral 85Rb atoms for an ion-atom mass ratio where most theoretical models predict ion heating. We demonstrate, based on detailed numerical simulation of our ion-cooling model, which is in excellent agreement with experiments, that cooling of ions by localized cold atoms is possible for any mass ratio. Our result opens up the possibility of studying quantum collisions and chemistry in trapped atom-ion systems.

  3. Hexapole-compensated magneto-optical trap on a mesoscopic atom chip

    DEFF Research Database (Denmark)

    Jöllenbeck, S.; Mahnke, J.; Randoll, R.;

    2011-01-01

    Magneto-optical traps on atom chips are usually restricted to small atomic samples due to a limited capture volume caused primarily by distorted field configurations. Here we present a magneto-optical trap based on a millimeter-sized wire structure which generates a magnetic field with minimized...

  4. Ultracold atomic collisions in tight harmonic traps: Perturbation theory, ionization losses and application to metastable helium atoms

    CERN Document Server

    Beams, T J; Whittingham, I B

    2004-01-01

    Collisions between tightly confined atoms can lead to ionization and hence to loss of atoms from the trap. We develop second-order perturbation theory for a tensorial perturbation of a spherically symmetric system and the theory is then applied to processes mediated by the spin-dipole interaction. Redistribution and loss mechanisms are studied for the case of spin-polarized metastable helium atoms and results obtained for the five lowest s states in the trap and trapping frequencies ranging from 1 kHz to 10 MHz.

  5. Bichromatic State-Insensitive Trapping of Cold 133Cs-87Rb Atomic Mixtures

    OpenAIRE

    Metbulut, M. M.; Renzoni, F.

    2015-01-01

    We investigate simultaneous state-insensitive trapping of a mixture of two different atomic species, Caesium and Rubidium. The magic wavelengths of the Caesium and Rubidium atoms are different, $935.6$ nm and $789.9$ nm respectively, thus single-frequency simultaneous state-insensitive trapping is not possible. We thus identify bichromatic trapping as a viable approach to tune the two magic wavelengths to a common value. Correspondingly, we present several common magic wavelength combinations...

  6. Reconfigurable self-sufficient traps for ultracold atoms based on a superconducting square

    CERN Document Server

    Siercke, M; Zhang, B; Beian, M; Lim, M J; Dumke, R

    2012-01-01

    We report on the trapping of ultracold atoms in the magnetic field formed entirely by persistent supercurrents induced in a thin film type-II superconducting square. The supercurrents are carried by vortices induced in the 2D structure by applying two magnetic field pulses of varying amplitude perpendicular to its surface. This results in a self-sufficient quadrupole trap that does not require any externally applied fields. We investigate the trapping parameters for different supercurrent distributions. Furthermore, to demonstrate possible applications of these types of supercurrent traps we show how a central quadrupole trap can be split into four traps by the use of a bias field.

  7. Recent developments in trapping and manipulation of atoms with adiabatic potentials

    Science.gov (United States)

    Garraway, Barry M.; Perrin, Hélène

    2016-09-01

    A combination of static and oscillating magnetic fields can be used to ‘dress’ atoms with radio-frequency (RF), or microwave, radiation. The spatial variation of these fields can be used to create an enormous variety of traps for ultra-cold atoms and quantum gases. This article reviews the type and character of these adiabatic traps and the applications which include atom interferometry and the study of low-dimensional quantum systems. We introduce the main concepts of magnetic traps leading to adiabatic dressed traps. The concept of adiabaticity is discussed in the context of the Landau-Zener model. The first bubble trap experiment is reviewed together with the method used for loading it. Experiments based on atom chips show the production of double wells and ring traps. Dressed atom traps can be evaporatively cooled with an additional RF field, and a weak RF field can be used to probe the spectroscopy of the adiabatic potentials. Several approaches to ring traps formed from adiabatic potentials are discussed, including those based on atom chips, time-averaged adiabatic potentials and induction methods. Several proposals for adiabatic lattices with dressed atoms are also reviewed.

  8. Magneto-Optical Trapping of Ytterbium Atoms with a 398.9 nm Laser

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng-Yi; XIONG Zhuan-Xian; LIANG Jie; HE Ling-Xiang; LU Bao-Long

    2008-01-01

    We report the realization of ytterbium magneto-optical trap (MOT) operating on the dipole-allowed 1S0 - 1P1 transition at 398.9nm. The MOT is loaded by a slowed atomic beam produced by a Zeeman slower. All seven stable isotopes of Yb atoms could be trapped separately at different laser detuning values. Over 107 174Yb atoms are collected in the MOT, whereas the atom number of fermionic isotope 171Yb is roughly 2.3 × 106 due to a lower abundance. Without the Zeeman slower, the trapped atom numbers are one order of magnitude lower.Both the even and odd isotopes are recognized as excellent candidates of optical clock transition, so the cooling and trapping of ytterbium atoms by the blue MOT is an important step for building an optical clock.

  9. Magneto-optical trapping of ytterbium atoms with a 398.9 nm laser

    International Nuclear Information System (INIS)

    We report the realization of ytterbium magneto-optical trap (MOT) operating on the dipole-allowed 1S0-1P1 transition at 398.9 nm. The MOT is loaded by a slowed atomic beam produced by a Zeeman slower. All seven stable isotopes of Yb atoms could be trapped separately at different laser detuning values. Over 107 174Yb atoms are collected in the MOT, whereas the atom number of fermionic isotope 171Yb is roughly 2.3 × 106 due to a lower abundance. Without the Zeeman slower, the trapped atom numbers are one order of magnitude lower. Both the even and odd isotopes are recognized as excellent candidates of optical clock transition, so the cooling and trapping of ytterbium atoms by the blue MOT is an important step for building an optical clock. (authors)

  10. Compact atomic clock prototype based on coherent population trapping

    Directory of Open Access Journals (Sweden)

    Danet Jean-Marie

    2014-01-01

    Full Text Available Toward the next generations of compact atomic clocks, clocks based on coherent population trapping (CPT offer a very interesting alternative. Thanks to CPT, a quantum interfering process, this technology has made a decisive step in the miniaturization direction. Fractional frequency stability of 1.5x10-10 at 1 s has been demonstrated in commercial devices of a few cm3. The laboratory prototype presented here intends to explore what could be the ultimate stability of a CPT based device. To do so, an original double-Λ optical scheme and a pulsed interrogation have been implemented in order to get a good compromise between contrast and linewidth. A study of two main sources of noise, the relative intensity and the local oscillator (LO noise, has been performed. By designing simple solutions, it led to a new fractional frequency limitation lower than 4x10-13 at 1 s integration. Such a performance proves that such a technology could rival with classical ones as double resonance clocks.

  11. Self-organization effects and light amplification of collective atomic recoil motion in a harmonic trap

    OpenAIRE

    Zhang, L.; Yang, G. J.; Xia, L. X.

    2005-01-01

    Self-organization effects related to light amplification in the collective atomic recoil laser system with the driven atoms confined in a harmonic trap are investigated further. In the dispersive parametric region, our study reveals that the spontaneously formed structures in the phase space contributes an important role to the light amplification of the probe field under the atomic motion being modified by the trap.

  12. Design, fabrication and characterization of tunable external cavity diode laser and atom trapping chips for atomic physics

    Science.gov (United States)

    Chuang, Ho-Chiao

    External cavity diode laser systems (ECDLs) have been well documented for their suitability in the fields of laser cooling and atom trapping, and are now widely used in optical and atomic physics. A particularly simple implementation of this idea uses feedback from a diffraction grating mounted in the Littrow configuration and the typical size of this laser is quite large (120mmx90mmx90mm). For atom optics, the current atom trapping chips are not in a feedthrough configuration, which makes the chips to glass cell assembly process complicated and the wires and solder areas vulnerable, resulting in an unreliable vacuum seal. Recent experimental realizations of atom optical devices such as atomic waveguides, beam splitters, and on-chip Bose-Einstein condensate (BEC) sources have opened a new field for the development of more complex devices such as, e.g., BEC-based atom transistor. This work focuses on micro/nano fabrication techniques to build three different devices for the miniature BEC system. The research work focuses on the development of new ECDLs, a novel fabrication process of feedthrough atom trapping chips for atomic optics and a fabrication process for atom transistor chips. In the ECDLs part, we describe a new method for constructing a smaller external-cavity diode laser by use of a micromachined silicon flexure and a VHG (Volume Holographic Grating). It is much smaller, inexpensive and easy to build because it is based on simple modifications of a few commercial optical and mechanical components but with a specific silicon flexure design enabled by micro-fabrication technology for the laser frequency tuning. In the feedthrough chips part, we present a novel fabrication process for feedthrough atom trapping chips in atomic condensate optics cells using the copper electroplating to seal the vias. The advantages of using feedthrough atom trapping chips are the simple microfabrication process and reduction of the overall chip area bonded on the glass atom-trapping

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

    Science.gov (United States)

    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.

  14. Polarimetric measurement of the motion of trapped atoms around a nanofiber

    Science.gov (United States)

    Fatemi, F. K.; Solano, P.; Orozco, L. A.; Rolston, S. L.

    2016-05-01

    Polarimetry is an important tool for probing the classical and quantum dynamics of a collection of trapped atoms. We observe the birefringence induced by trapped Rb atoms around an optical nanofiber by measuring the polarization change of an off-resonant probe. The signal from the weak, non-destructive probe is amplified using heterodyne detection. We observe the dynamical response of the trapped atoms to a transient modification of the trapping potential. This provides a direct measurement of the trapping frequencies associated with the axial and transverse potentials. The presence of large longitudinal fields in the evanescent field of the fiber complicates polarimetry, presenting significant challenges for the observation of atomic spin dynamics through Faraday rotation measurements. Work supported by NSF.

  15. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine

  16. Magneto-optical trap formed by elliptically polarised light waves for Mg atoms

    Science.gov (United States)

    Prudnikov, O. N.; Brazhnikov, D. V.; Taichenachev, A. V.; Yudin, V. I.; Goncharov, A. N.

    2016-07-01

    We consider a magneto-optical trap (MOT) formed by elliptically polarised waves for 24Mg atoms on a closed optical 3P2 → 3D3 (λ = 383.8 nm) transition in the ɛ - θ - ɛ¯ configuration of the field. Compared with a known MOT formed by circularly polarised waves (σ+ - σ- configuration), the suggested configuration of the trap formed by fields of ɛ - θ - ɛ¯ configuration allows deeper sub-Doppler cooling of trapped 24Mg atoms, which cannot be implemented in a conventional trap formed by fields of σ+ - σ- configuration.

  17. Emission spectrum of a harmonically trapped A-type three-level atom

    Institute of Scientific and Technical Information of China (English)

    Guo Hong; Tang Pei

    2013-01-01

    We theoretically investigate the emission spectrum for a ∧-type three-level atom trapped in the node of a standing wave.We show that the atomic center-of-mass motion not only directly affects the peak number,peak position,and peak height in the atomic emission spectrum,but also influences the effects of the cavity field and the atomic initial state on atomic emission spectrum.

  18. Trapping of Atoms by the Counter-Propagating Stochastic Light Waves

    CERN Document Server

    Romanenko, Victor I

    2016-01-01

    We show that the field of counter-propagating stochastic light waves, one of which repeats the other, can form an one-dimension trap for atoms. The confinement of an ensemble of atoms in the trap and their simultaneous cooling can be achieved without using auxiliary fields. The temperature of the atomic ensemble depends on the autocorrelation time of the waves, their intensity and the detuning of the carrier frequency of the waves from the atomic transition frequency. The numerical simulation is carried out for sodium atoms.

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

    CERN Document Server

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

    2015-01-01

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer 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, or precision sensing.

  20. A double-well atom trap for fluorescence detection at the Heisenberg limit

    CERN Document Server

    Stroescu, Ion; Oberthaler, Markus K

    2014-01-01

    We experimentally demonstrate an atom number detector capable of simultaneous detection of two mesoscopic ensembles with single atom resolution. Such a sensitivity is a prerequisite for going beyond quantum metrology with spin-squeezed states. Our system is based on fluorescence detection of atoms in a novel hybrid trap in which a dipole barrier divides a magneto-optical trap into two separated wells. We introduce a noise model describing the various sources contributing to the measurement error and report a limit of up to 500 atoms for the exact determination of the atom number difference.

  1. Fiber-pigtailed optical tweezer for single-atom trapping and single-photon generation

    CERN Document Server

    Garcia, Sébastien; Hohmann, Leander; Reichel, Jakob; Long, Romain

    2013-01-01

    We demonstrate a miniature, fiber-coupled optical tweezer to trap a single atom. The same fiber is used to trap a single atom and to read out its fluorescence. To obtain a low background level, the tweezer light is chopped, and we measure the influence of the chopping frequency on the atom's lifetime. We use the single atom as a single-photon source at 780 nm and measure the second-order correlation function of the emitted photons. Because of its miniature, robust, fiber-pigtailed design, this tweezer can be implemented in a broad range of experiments where single atoms are used as a resource.

  2. Observation of single neutral atoms in a large-magnetic-gradient vapour-cell magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; He Jun; Qiu Ying; Yang Bao-Dong; Zhao Jiang-Yan; Zhang Tian-Cai; Wang Jun-Min

    2008-01-01

    Single caesium atoms in a large-magnetic-gradient vapour-cell magneto-optical trap have been identified. The trapping of individual atoms is marked by the steps in fluorescence signal corresponding to the capture or loss of single atoms. The typical magnetic gradient is about 29 mT/cm, which evidently reduces the capture rate of magneto-optical trap.

  3. Fast compression of a cold atomic cloud using a blue detuned crossed dipole trap

    CERN Document Server

    Bienaime, Tom; de Lepinay, Laure Mercier; Bellando, Louis; Chabe, Julien; Kaiser, Robin

    2012-01-01

    We present the experimental realization of a compressible blue detuned crossed dipole trap for cold atoms allowing for fast dynamical compression (~ 5 - 10 ms) of 5x10^7 Rubidium atoms up to densities of ~ 10^13 cm^-3. The dipole trap consists of two intersecting tubes of blue-detuned laser light. These tubes are formed using a single, rapidly rotating laser beam which, for sufficiently fast rotation frequencies, can be accurately described by a quasi-static potential. The atomic cloud is compressed by dynamically reducing the trap volume leading to densities close to the Ioffe-Reggel criterion for light localization.

  4. Continuous loading of $^{1}$S$_{0}$ calcium atoms into an optical dipole trap

    OpenAIRE

    Yang, C. Y.; Halder, P.; Appel, O.; Hansen, D.; Hemmerich, A.

    2007-01-01

    We demonstrate an efficient scheme for continuous trap loading based upon spatially selective optical pumping. We discuss the case of $^{1}$S$_{0}$ calcium atoms in an optical dipole trap (ODT), however, similar strategies should be applicable to a wide range of atomic species. Our starting point is a reservoir of moderately cold ($\\approx 300 \\mu$K) metastable $^{3}$P$_{2}$-atoms prepared by means of a magneto-optic trap (triplet-MOT). A focused 532 nm laser beam produces a strongly elongate...

  5. An ultracold, optically trapped mixture of {87}Rb and metastable {4}He atoms

    CERN Document Server

    Flores, Adonis Silva; Vassen, Wim; Knoop, Steven

    2016-01-01

    We report on the realization of an ultracold (<25~muK) mixture of rubidium ({87}Rb) and metastable triplet helium ({4}He) in an optical dipole trap. Our scheme involves laser cooling in a dual-species magneto-optical trap, simultaneous MW- and RF-induced forced evaporative cooling in a quadrupole magnetic trap, and transfer to a single-beam optical dipole trap. We observe long trapping lifetimes for the doubly spin-stretched spin-state mixture and measure much shorter lifetimes for other spin-state combinations. We discuss prospects for realizing quantum degenerate mixtures of alkali-metal and metastable helium atoms.

  6. First principles investigation of cluster consisting of hydrogen–helium atoms interstitially-trapped in tungsten

    International Nuclear Information System (INIS)

    We evaluate the binding energies of mixed helium and hydrogen clusters consisted of interstitially trapped atoms in bcc tungsten by first-principles calculations based on density functional theories. It is shown that helium-rich interstitially-trapped clusters have the positive binding energies and the low electron-density region expand as the number of helium in the cluster increase. Thus, the helium-rich interstitially trapped clusters can act as a trapping site for hydrogen, and interstitially trapped helium interrupts or disturbs the hydrogen diffusion in tungsten

  7. Continuous loading of cold atoms into a Ioffe-Pritchard magnetic trap

    CERN Document Server

    Schmidt, P O; Werner, J; Binhammer, T; Görlitz, A; Pfau, T; Schmidt, Piet O.; Hensler, Sven; Werner, Joerg; Binhammer, Thomas; Goerlitz, Axel; Pfau, Tilman

    2002-01-01

    We present a robust continuous optical loading scheme for a Ioffe-Pritchard (IP) type magnetic trap. Atoms are cooled and trapped in a modified magneto-optical trap (MOT) consisting of a conventional 2D-MOT in radial direction and an axial molasses. The radial magnetic field gradient needed for the operation of the 2D-MOT is provided by the IP trap. A small axial curvature and offset field provide magnetic confinement and suppress spin-flip losses in the center of the magnetic trap without altering the performance of the 2D-MOT. Continuous loading of atoms into the IP trap is provided by radiative leakage from the MOT to a metastable level which is magnetically trapped and decoupled from the MOT light. We are able to accumulate 30 times more atoms in the magnetic trap than in the MOT. The absolute number of $2\\times 10^8$~atoms is limited by inelastic collisions. A model based on rate equations shows good agreement with our data. Our scheme can also be applied to other atoms with similar level structure like ...

  8. A novel method for trapping and analyzing 15N in NO for tracing NO sources

    Science.gov (United States)

    Kang, Ronghua; Mulder, Jan; Dörsch, Peter

    2016-04-01

    15N isotope tracing is an effective and direct approach to investigate the biological and chemical sources of nitric oxide (NO) in soil. However, NO is highly reactive and rapidly converted to nitrogen dioxide (NO2) in the presence of ozone. Various chemical conversions of NO to the more stable solutes nitrite (NO2-) and nitrate (NO3-) have been proposed, which allow analysing the 15N abundance without major fractionation. However, NO emissions from soils are usually small, posing major challenges to conversion efficiency and background contamination. Here we present a novel method in which NO is oxidized to NO2- by chromium trioxide (CrO3) prior to conversion to NO2- and NO3- in an alkaline hydrogen peroxide (H2O2) solution. Immediately following trapping, manganese dioxide (MnO2) and 5M HCl are added to remove excess H2O2, and to adjust the pH to around 6.0-7.0, respectively. The resulting solution can be stored until analysis and is none-toxic, allowing to use a modified denitrifier method (Zhu et al., submitted), where NO2- and NO3- are reduced quantitatively to nitrous oxide (N2O). Optimum NO conversion rates of > 90% even at extremely low initial NO concentration were obtained with 4% H2O2, 0.5 M NaOH, and 0.5 L min-1 gas flow rate. In a laboratory test, using NO gas with different 15N signals produced from unlabelled and labelled NO2-, we found an overall precision of 0.4‰ for unlabelled and 49.7‰ for NO enriched with 1.0 atom% 15N, respectively. This indicates that this method can be used for both natural abundance studies of NO, as well as in labelling studies tracing NO sources. Zhu J, Yu L, Bakken LR, Mørkved PT, Mulder J, Dörsch P. Controlled induction of denitrification in Pseudomonas aureofaciens: a modified denitrifier method for 15N and 18O analysis in NO3- from natural water samples by IRMS. Submitted.

  9. Single-atom trapping in holographic 2D arrays of microtraps with arbitrary geometries

    CERN Document Server

    Nogrette, Florence; Ravets, Sylvain; Barredo, Daniel; Béguin, Lucas; Vernier, Aline; Lahaye, Thierry; Browaeys, Antoine

    2014-01-01

    We demonstrate single-atom trapping in two-dimensional arrays of microtraps with arbitrary geometries. We generate the arrays using a Spatial Light Modulator (SLM), with which we imprint an appropriate phase pattern on an optical dipole trap beam prior to focusing. We trap single $^{87}{\\rm Rb}$ atoms in the sites of arrays containing up to $\\sim100$ microtraps separated by distances as small as $3\\;\\mu$m, with complex structures such as triangular, honeycomb or kagome lattices. Using a closed-loop optimization of the uniformity of the trap depths ensures that all trapping sites are equivalent. This versatile system opens appealing applications in quantum information processing and quantum simulation, e.g. for simulating frustrated quantum magnetism using Rydberg atoms.

  10. Trapping atoms in the evanescent field of laser written wave guides

    CERN Document Server

    Jukic, Dario; Walther, P; Szameit, A; Pohl, T; Götte, J B

    2016-01-01

    We analyze evanescent fields of laser written waveguides and show that they can be used to trap atoms close to the surface of an integrated optical atom chip. In contrast to subwavelength nanofibres it is generally not possible to create a stable trapping potential using only the fundamental modes. This is why we create a stable trapping potential by using two different laser colors, such that the waveguide supports two modes for the blue detuned laser, while for the red detuned light the waveguide has only a single mode. In particular, we study such a two-color trap for Cesium atoms, and calculate both the potential and losses for the set of parameters that are within experimental reach. We also optimize system parameters in order to minimize trap losses due to photon scattering and tunneling to the surface.

  11. Ultratrace determination of lead by hydride generation in-atomizer trapping atomic absorption spectrometry: Optimization of plumbane generation and analyte preconcentration in a quartz trap-and-atomizer device

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz

    2012-05-15

    A compact trap-and-atomizer device and a preconcentration procedure based on hydride trapping in excess of oxygen over hydrogen in the collection step, both constructed and developed previously in our laboratory, were employed to optimize plumbane trapping in this device and to develop a routine method for ultratrace lead determination subsequently. The inherent advantage of this preconcentration approach is that 100% preconcentration efficiency for lead is reached in this device which has never been reported before using quartz or metal traps. Plumbane is completely retained in the trap-and-atomizer device at 290 Degree-Sign C in oxygen-rich atmosphere and trapped species are subsequently volatilized at 830 Degree-Sign C in hydrogen-rich atmosphere. Effect of relevant experimental parameters on plumbane trapping and lead volatilization are discussed, and possible trapping mechanisms are hypothesized. Plumbane trapping in the trap-and-atomizer device can be routinely used for lead determination at ultratrace levels reaching a detection limit of 0.21 ng ml{sup -1} Pb (30 s preconcentration, sample volume 2 ml). Further improvement of the detection limit is feasible by reducing the blank signal and increasing the trapping time. - Highlights: Black-Right-Pointing-Pointer In-atomizer trapping HG-AAS was optimized for Pb. Black-Right-Pointing-Pointer A compact quartz trap-and-atomizer device was employed. Black-Right-Pointing-Pointer Generation, preconcentration and atomization steps were investigated in detail. Black-Right-Pointing-Pointer 100% preconcentration efficiency for lead was reached. Black-Right-Pointing-Pointer Routine analytical method was developed for Pb determination (LOD of 0.2 ng ml{sup -1} Pb).

  12. Velocity selective trapping of atoms in a frequency-modulated standing laser wave

    CERN Document Server

    Argonov, V Yu

    2013-01-01

    The wave function of a moderately cold atom in a stationary near-resonant standing light wave delocalizes very fast due to wave packet splitting. However, we show that frequency modulation of the field may suppress packet splitting for some atoms having specific velocities in a narrow range. These atoms remain localized in a small space for a long time. We propose that in a real experiment with cold atomic gas this effect may decrease the velocity distribution of atoms (the field traps the atoms with such specific velocities while all other atoms leave the field)

  13. Magneto-optical trapping of radioactive atoms for test of the fundamental symmetries

    International Nuclear Information System (INIS)

    We are planning test experiments of fundamental symmetries based on the intrinsic properties of francium. It is expected that the laser cooling and trapping of francium will produce precision measurements. The pilot experiment using rubidium was performed with the goal of francium trapping. The ion beam generated with a francium ion source was investigated using a Wien filter. Each piece of equipment still must be studied in more detail, and the equipment should be upgraded in order to trap radioactive atoms

  14. Magneto-optical trapping of radioactive atoms for test of the fundamental symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hirokazu, E-mail: hirokazu.kawamura.c2@tohoku.ac.jp [Tohoku University, Frontier Research Institute for Interdisciplinary Sciences (Japan); Ando, S.; Aoki, T.; Arikawa, H.; Harada, K.; Hayamizu, T. [Tohoku University, Cyclotron and Radioisotope Center (Japan); Inoue, T. [Tohoku University, Frontier Research Institute for Interdisciplinary Sciences (Japan); Ishikawa, T.; Itoh, M.; Kato, K.; Köhler, L.; Mathis, J.; Sakamoto, K.; Uchiyama, A.; Sakemi, Y. [Tohoku University, Cyclotron and Radioisotope Center (Japan)

    2015-11-15

    We are planning test experiments of fundamental symmetries based on the intrinsic properties of francium. It is expected that the laser cooling and trapping of francium will produce precision measurements. The pilot experiment using rubidium was performed with the goal of francium trapping. The ion beam generated with a francium ion source was investigated using a Wien filter. Each piece of equipment still must be studied in more detail, and the equipment should be upgraded in order to trap radioactive atoms.

  15. Entanglement and quantum state transfer between two atoms trapped in two indirectly coupled cavities

    Science.gov (United States)

    Zheng, Bin; Shen, Li-Tuo; Chen, Ming-Feng

    2016-05-01

    We propose a one-step scheme for implementing entanglement generation and the quantum state transfer between two atomic qubits trapped in two different cavities that are not directly coupled to each other. The process is realized through engineering an effective asymmetric X-Y interaction for the two atoms involved in the gate operation and an auxiliary atom trapped in an intermediate cavity, induced by virtually manipulating the atomic excited states and photons. We study the validity of the scheme as well as the influences of the dissipation by numerical simulation and demonstrate that it is robust against decoherence.

  16. Observation of three-level rectified dipole forces acting on trapped atoms

    Science.gov (United States)

    Grove, T. T.; Duncan, B. C.; Sanchez-Villicana, V.; Gould, P. L.

    1995-06-01

    We have observed rectified dipole forces acting on three-level atoms in the cascade configuration. Laser cooled and trapped rubidium atoms are illuminated with an intense bichromatic standing wave (780 and 776 nm) tuned near resonance with the 5S1/2-->5P3/2-->5D5/2 transitions. The resulting rectified forces produce periodic potential wells (71-μm period), which localize the cold atoms. Experimental results are in reasonable agreement with theoretical predictions. These forces may be useful in atom optics and laser traps.

  17. Trapping of ultra cold atoms in a 3He/4He dilution refrigerator

    CERN Document Server

    Jessen, F; Bell, S C; Vergien, P; Hattermann, H; Weiss, P; Rudolph, M; Reinschmidt, M; Meyer, K; Gaber, T; Cano, D; Guenther, A; Bernon, S; Koelle, D; Kleiner, R; Fortagh, J

    2013-01-01

    We describe the preparation of ultra cold atomic clouds in a dilution refrigerator. The closed cycle 3He/4He cryostat was custom made to provide optical access for laser cooling, optical manipulation and detection of atoms. We show that the cryostat meets the requirements for cold atom experiments, specifically in terms of operating a magneto-optical trap, magnetic traps and magnetic transport under ultra high vacuum conditions. The presented system is a step towards the creation of a quantum hybrid system combining ultra cold atoms and solid state quantum devices.

  18. Influence of the atomic-wall collision elasticity on the coherent population trapping resonance shape

    OpenAIRE

    Kazakov, G A; Litvinov, A. N.; Matisov, B. G.; Romanenko, V. I.; Yatsenko, L. P.; Romanenko, A. V.

    2011-01-01

    We studied theoretically a coherent population trapping resonance formation in cylindrical cell without buffer gas irradiated by a narrow laser beam. We take into account non-zero probabilities of elastic ("specular") and inelastic ("sticking") collision between the atom and the cell wall. We have developed a theoretical model based on averaging over the random Ramsey pulse sequences of times that atom spent in and out of the beam. It is shown that the shape of coherent population trapping re...

  19. Strong coupling between a trapped single atom and an all-fiber cavity

    CERN Document Server

    Kato, Shinya

    2015-01-01

    We demonstrate an all-fiber cavity QED system with a trapped single atom in the strong coupling regime. We use a nanofiber Fabry-Perot cavity, that is, an optical nanofiber sandwiched by two fiber-Bragg-grating mirrors. Measurements of the cavity transmission spectrum with a single atom in a state-insensitive nanofiber trap clearly reveal the vacuum Rabi splitting. Our system provides a simple and robust implementation of a large-scale all-fiber quantum network.

  20. Strong Coupling between a Trapped Single Atom and an All-Fiber Cavity.

    Science.gov (United States)

    Kato, Shinya; Aoki, Takao

    2015-08-28

    We demonstrate an all-fiber cavity quantum electrodynamics system with a trapped single atom in the strong coupling regime. We use a nanofiber Fabry-Perot cavity, that is, an optical nanofiber sandwiched by two fiber-Bragg-grating mirrors. Measurements of the cavity transmission spectrum with a single atom in a state-insensitive nanofiber trap clearly reveal the vacuum Rabi splitting. PMID:26371652

  1. Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap

    CERN Document Server

    Li, Y; Feng, G; Nute, J; Piano, S; Hackermuller, L; Ma, J; Xiao, L; Jia, S

    2015-01-01

    We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loading magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load $1.5 \\times 10^7$ atoms into the Raman lattice with a detuning of -15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 $\\mu$K to 1.7 $\\mu$K within 12 ms and the number of obtained atoms is about $1.2 \\times 10^7$. A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.

  2. Effect of Trapping Agent and Polystyrene Chain End Functionality on Radical Trap-Assisted Atom Transfer Radical Coupling

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Carnicom

    2014-10-01

    Full Text Available Coupling reactions were performed to gauge the effect of the inclusion of a radical trap on the success of coupling reactions of monohalogenated polystyrene (PSX chains in atom transfer radical coupling (ATRC type reactions. The effect of both the specific radical trap chosen and the structure of the polymer chain end were evaluated by the extent of dimerization observed in a series of analogous coupling reactions. The commonly used radical trap 2-methyl-2-nitrosopropane (MNP showed the highest amounts of dimerization for PSX (X = Br, Cl compared to coupling reactions performed in its absence or with a different radical trap. A dinitroxide coupling agent was also studied with the extent of coupling nearly matching the effectiveness of MNP in RTA (Radical trap-assisted-ATRC reactions, while N-nitroso and electron rich nitroso coupling agents were the least effective. (2,2,6,6-Tetramethyl-piperin-l-yloxyl-capped PS (PS-TEMPO, prepared by NMP, was subjected to a coupling sequence conceptually similar to RTA-ATRC, but dimerization was not observed regardless of the choice of radical trap. Kinetic experiments were performed to observe rate changes on the coupling reaction of PSBr as a result of the inclusion of MNP, with substantial rate enhancements found in the RTA-ATRC coupling sequence compared to traditional ATRC.

  3. Simultaneous Magneto-Optical Trapping of Fermionic 40K and Bosonic 87Rb Atoms

    Institute of Scientific and Technical Information of China (English)

    WEI Dong; XIONG De-Zhi; CHEN Hai-Xia; WANG Peng-Jun; GUO Lu; ZHANG Jing

    2007-01-01

    We report on simultaneous magneto-optical trapping of fermionic 40K and bosonic 87Rb atoms. This trap is the first step towards quantum degenerate fermi gas 40K. Laser lights for the two-species magneto-optical trap (MOT) are generated from diode lasers and tapered amplifier. The enriched 40K dispenser is utilized in the experimental setup. We obtain up to 107 ~108 40K and 108 ~109 87Rb atoms respectively in the steady-state single-species MOT.

  4. Trapping of Neutral Mercury Atoms and Prospects for Optical Lattice Clocks

    OpenAIRE

    Hachisu, H.; Miyagishi, K.; Porsev, S. G.; Derevianko, A.; Ovsiannikov, V. D.; Pal'chikov, V. G.; Takamoto, M.; Katori, H.

    2007-01-01

    We report a vapor-cell magneto-optical trapping of Hg isotopes on the ${}^1S_0-{}^3P_1$ intercombination transition. Six abundant isotopes, including four bosons and two fermions, were trapped. Hg is the heaviest non-radioactive atom trapped so far, which enables sensitive atomic searches for ``new physics'' beyond the standard model. We propose an accurate optical lattice clock based on Hg and evaluate its systematic accuracy to be better than $10^{-18}$. Highly accurate and stable Hg-based ...

  5. Trapping of neutral mercury atoms and prospects for optical lattice clocks.

    Science.gov (United States)

    Hachisu, H; Miyagishi, K; Porsev, S G; Derevianko, A; Ovsiannikov, V D; Pal'chikov, V G; Takamoto, M; Katori, H

    2008-02-01

    We report vapor-cell magneto-optical trapping of Hg isotopes on the (1)S(0)-(3)P(1) intercombination transition. Six abundant isotopes, including four bosons and two fermions, were trapped. Hg is the heaviest nonradioactive atom trapped so far, which enables sensitive atomic searches for "new physics" beyond the standard model. We propose an accurate optical lattice clock based on Hg and evaluate its systematic accuracy to be better than 10;{-18}. Highly accurate and stable Hg-based clocks will provide a new avenue for the research of optical lattice clocks and the time variation of the fine-structure constant. PMID:18352368

  6. Trapping of Neutral Mercury Atoms and Prospects for Optical Lattice Clocks

    CERN Document Server

    Hachisu, H; Porsev, S G; Derevianko, A; Ovsiannikov, V D; Pal'chikov, V G; Takamoto, M; Katori, H

    2007-01-01

    We report a vapor-cell magneto-optical trapping of Hg isotopes on the ${}^1S_0-{}^3P_1$ intercombination transition. Six abundant isotopes, including four bosons and two fermions, were trapped. Hg is the heaviest non-radioactive atom trapped so far, which enables sensitive atomic searches for ``new physics'' beyond the standard model. We propose an accurate optical lattice clock based on Hg and evaluate its systematic accuracy to be better than $10^{-18}$. Highly accurate and stable Hg-based clocks will provide a new avenue for the research of optical lattice clocks and the time variation of the fine-structure constant.

  7. Multiscale quantum-defect theory for two interacting atoms in a symmetric harmonic trap

    OpenAIRE

    Chen, Yujun; Gao, Bo

    2007-01-01

    We present a multiscale quantum-defect theory (QDT) for two identical atoms in a symmetric harmonic trap that combines the quantum-defect theory for the van der Waals interaction [B. Gao, Phys. Rev. A \\textbf{64}, 010701(R) (2001)] at short distances with a quantum-defect theory for the harmonic trapping potential at large distances. The theory provides a systematic understanding of two atoms in a trap, from deeply bound molecular states and states of different partial waves, to highly excite...

  8. Lattices of ultracold atom traps over arrays of nano- and mesoscopic superconducting disks

    Science.gov (United States)

    Sokolovsky, Vladimir; Prigozhin, Leonid

    2016-04-01

    A lattice of traps for ultracold neutral atoms is a promising tool for experimental investigation in quantum physics and quantum information processing. We consider regular arrays of thin film type-II superconducting nanodisks, with only one pinned vortex in each of them, and also arrays of mesoscopic disks, each containing many vortices whose distribution is characterized by the superconducting current density. In both cases we show theoretically that the induced magnetic field can create a 3D lattice of magnetic traps for cold atoms without any additional bias field. Applying a bias DC field parallel to the superconductor surface, one can control the depth and sizes of the traps, their heights above the chip surface, potential barriers between the traps, as well as the structure and dimension of the lattices. In the adiabatic approximation the atom cloud shape is represented by the shape of a closed iso-surface of the magnetic field magnitude chosen in accordance with the atom cloud temperature. The computed trap sizes, heights and the distances between the neighboring traps are typically from tens to hundreds nanometers for nanodisks and of the order of 1 μm for mesoscopic disks. Our calculations show that the depth of magnetic traps on mesoscopic disks is, typically, between 0.3 G and 7.6 G; for the nanodisks the depth is about 0.3 G.

  9. Coherence preservation of a single neutral atom qubit transferred between magic-intensity optical traps

    CERN Document Server

    Yang, Jiaheng; Guo, Ruijun; Xu, Peng; Wang, Kunpeng; Sheng, Cheng; Liu, Min; Wang, Jin; Derevianko, Andrei; Zhan, Mingsheng

    2016-01-01

    We demonstrate that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs). This is a prerequisite step in realizing a large-scale neutral atom quantum information processing platform. A qubit encoded in the hyperfine manifold of $^{87}$Rb atom is dynamically extracted from the static quantum register by an auxiliary moving ODT and reinserted into the static ODT. Previous experiments were limited by decoherences induced by the differential light shifts of qubit states. Here we apply a magic-intensity trapping technique which mitigates the detrimental effects of light shifts and substantially enhances the coherence time to $225 \\pm 21\\,\\mathrm{ms}$. The experimentally demonstrated magic trapping technique relies on the previously neglected hyperpolarizability contribution to the light shifts, which makes the light shift dependence on the trapping laser intensity to be parabolic. Because of the parabolic dependence, at a certain ...

  10. Generation of Three-Dimensional Entangled States for Two Atoms Trapped in Different Cavities

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Biao

    2005-01-01

    @@ We propose a scheme for generating three-dimensional entangled states for two atoms trapped in two separate cavities. The scheme is based on the detection of photons leaking from the cavities after the atom-cavity interaction.The scheme is useful for the test of quantum nonlocality and quantum information processing.

  11. Cooling and trapping of three-level atoms in a bichromatic standing wave

    Science.gov (United States)

    Pu, H.; Cai, T.; Bigelow, N. P.; Grove, T. T.; Gould, P. L.

    1995-02-01

    We show that a three-level atom in the cascade configuration can be stably trapped and cooled in one dimension by an intense bichromatic standing wave. At the two-photon resonance, rectified dipole forces result in a deep potential well which can be used to localize the atoms in space. In the vicinity of the rectified potential minimum, the spatial dependence of the dressed state energies can lead to a velocity dependence of the force which produces damping of the atomic motion. Consideration of the heating effects of momentum diffusion indicates that cooling and stable trapping at low temperatures is possible in such a bichromatic field.

  12. C60 as an Atom Trap to Capture Co Adatoms

    DEFF Research Database (Denmark)

    Yang, Peng; Li, Dongzhe; Repain, Vincent;

    2015-01-01

    to efficiently allow the formation of complexes mixing a C60 molecule with Co atoms. Scanning tunneling spectroscopy reveals the robustness of the pi states of C60 that are preserved after Co trapping. Scanning tunneling microscopy images and density functional theory calculations reveal that dissociated Co......C60 molecules were used to trap Co adatoms and clusters on a Au(111) surface using atomic/molecular manipulation with a scanning tunneling microscope. Two manipulation pathways (successive integration of single Co atoms in one molecule or direct integration of a Co cluster) were found...

  13. Exact spatial density of ideal Bose atoms in a one-dimensional harmonic trap

    Science.gov (United States)

    Cheng, Ze

    2016-05-01

    We have proposed an exact analytical solution to the problem of Bose–Einstein condensation (BEC) of harmonically trapped, one-dimensional, and ideal atoms. It is found that the number of atoms in vapor is characterized by an analytical function, which involves a q -digamma function in mathematics. We employ the q -digamma function to calculate the spatial density n(z;T, N) of ideal Bose atoms in a one-dimensional harmonic trap. The first main finding in this paper is that when Bose atoms are in the normal state, the density profile exhibits Friedel oscillations. The second main finding is that when Bose atoms are in the BEC state, the density profile exhibits a sharp peak with extremely narrow width. The third main finding is that the central peak of the spatial density is a monotonically increasing function of the number of atoms N but is a monotonically decreasing function of temperature T.

  14. Velocity tuning of friction with two trapped atoms

    CERN Document Server

    Gangloff, Dorian; Counts, Ian; Jhe, Wonho; Vuletić, Vladan

    2015-01-01

    Friction is the basic, ubiquitous mechanical interaction between two surfaces that results in resistance to motion and energy dissipation. In spite of its technological and economic significance, our ability to control friction remains modest, and our understanding of the microscopic processes incomplete. At the atomic scale, mismatch between the two contacting crystal lattices can lead to a reduction of stick-slip friction (structural lubricity), while thermally activated atomic motion can give rise to a complex velocity dependence, and nearly vanishing friction at sufficiently low velocities (thermal lubricity). Atomic force microscopy has provided a wealth of experimental results, but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a full quantitative description from first principles. Here, using an ion-crystal friction emulator with single-atom, single substrate-site spatial resolution and single-slip temporal resolution, we measure the friction force...

  15. Laser cooling of rubidium atoms in a magneto-optical trap

    OpenAIRE

    Hopkins, Stephen Anthony

    1996-01-01

    This thesis describes theoretical and experimental work concerning radiation forces on atoms, with particular reference to rubidium atoms confined in a magneto-optical trap. After a short history of the field of laser cooling, a review of the semiclassical theory of mechanical interactions between two-level atoms and electromagnetic radiation is given. Different formulations of the semiclassical theory are discussed, including a new formulation in terms of momentum transfer amongst the pl...

  16. Design and fabrication of diffractive atom chips for laser cooling and trapping

    CERN Document Server

    Cotter, J P; Griffin, P F; Rabey, I M; Docherty, K; Riis, E; Arnold, A S; Hinds, E A

    2016-01-01

    It has recently been shown that optical reflection gratings fabricated directly into an atom chip provide a simple and effective way to trap and cool substantial clouds of atoms [1,2]. In this article we describe how the gratings are designed and micro-fabricated and we characterise their optical properties, which determine their effectiveness as a cold atom source. We use simple scalar diffraction theory to understand how the morphology of the gratings determines the power in the diffracted beams.

  17. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    Science.gov (United States)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-07-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry.

  18. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    Science.gov (United States)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  19. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  20. Phase Space Diagnostics of Trapped Atoms By Magnetic Ground-State Manipulation

    Science.gov (United States)

    Cahn, S. B.; Kumarakrishnan, A.; Shim, U.; Sleator, T.

    1997-04-01

    The in-situ measurement of the phase space distribution of atoms in a trap is important in the study of both ordinary and Bose-condensed matter. The current techniques for measuring the density distribution involve imaging the light emitted by atoms in the trap, time-of-flight measurement of the atoms as they fall through a sheet of light(C.D. Wallace, et al, JOSA B,11),703 (1994), resonant absorption imaging of the cloud(J.R. Ensher, et al, PRL 77), 4984 (1996), or off-resonant dispersive imaging. The first two techniques are in general use for imaging magneto-optical traps (MOTs) and the second two for Bose condensates. Velocity information is obtained indirectly by recording the expansion of the trap at different times following shut-off. By exploiting the magnetic field dependence of ground-state magnetic sublevel coherences, we have employed two techniques, MGE and MGFID(B. Dubetsky and P.R. Berman, Appl. Phys. B, 59), 147 (1994), to obtain atomic spatial information. This variant of atomic beam magnetic imaging(J.E. Thomas and L.J. Wang, Physics Reports 262), 311-366 (1995) also yields correlated position-velocity information by appropriate orientation of the applied magnetic field, as the detuning of the atom depends on both its position and velocity. Initial studies have given the velocity distribution and size of the MOT, and future experiments to measure correlations are proposed.

  1. Influence of trapping potentials on the phase diagram of bosonic atoms in optical lattices

    OpenAIRE

    Giampaolo, S. M.; Illuminati, F.; Mazzarella, G.; De Siena, S.

    2004-01-01

    We study the effect of external trapping potentials on the phase diagram of bosonic atoms in optical lattices. We introduce a generalized Bose-Hubbard Hamiltonian that includes the structure of the energy levels of the trapping potential, and show that these levels are in general populated both at finite and zero temperature. We characterize the properties of the superfluid transition for this situation and compare them with those of the standard Bose-Hubbard description. We briefly discuss s...

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

    Science.gov (United States)

    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.

  3. Quantum information entropies of ultracold atomic gases in a harmonic trap

    Indian Academy of Sciences (India)

    Tutul Biswas; Tarun Kanti Ghosh

    2011-10-01

    The position and momentum space information entropies of weakly interacting trapped atomic Bose–Einstein condensates and spin-polarized trapped atomic Fermi gases at absolute zero temperature are evaluated. We find that sum of the position and momentum space information entropies of these quantum systems containing atoms confined in a $D(≤ 3)$-dimensional harmonic trap has a universal form as $S^{(D)}_t = N(a D − b ln N)$, where ∼ 2.332 and = 2 for interacting bosonic systems and a ∼ 1.982 and = 1 for ideal fermionic systems. These results obey the entropic uncertainty relation given by Beckner, Bialynicki-Birula and Myceilski.

  4. State-dependent potentials in a nanofiber-based two-color trap for cold atoms

    CERN Document Server

    Kien, Fam Le; Rauschenbeutel, Arno

    2013-01-01

    We analyze the ac Stark shift of a cesium atom interacting with far-off-resonance guided light fields in the nanofiber-based two-color optical dipole trap realized by Vetsch \\textit{et al.} [Phys. Rev. Lett. \\textbf{104}, 203603, (2010)]. Particular emphasis is given to the fictitious magnetic field produced by the vector polarizability of the atom in conjunction with the ellipticity of the polarization of the trapping fields. Taking into account the ac Stark shift, the atomic hyperfine interaction, and a magnetic interaction, we solve the stationary Schr\\"odinger equation at a fixed point in space and find Zeeman-state-dependent trapping potentials. In analogy to the dynamics in magnetic traps, a local degeneracy of these state-dependent trapping potentials can cause spin flips and should thus be avoided. We show that this is possible using an external magnetic field. Depending on the direction of this external magnetic field, the resulting trapping configuration can still exhibit state-dependent displacemen...

  5. Fluorescence spectra of atomic ensembles in a magneto-optical trap as an optical lattice

    CERN Document Server

    Yoon, Seokchan; Kang, Sungsam; Kim, Wook-Rae; Kim, Jung-Ryul; An, Kyungwon

    2015-01-01

    We present a study on characteristics of a magneto-optical trap (MOT) as an optical lattice. Fluorescence spectra of atoms trapped in a MOT with a passively phase-stabilized beam configuration have been measured by means of the photon-counting heterodyne spectroscopy. We observe a narrow Rayleigh peak and well-resolved Raman sidebands in the fluorescence spectra which clearly show that the MOT itself behaves as a three-dimensional optical lattice. Optical-lattice-like properties of the phase-stabilized MOT such as vibrational frequencies and lineshapes of Rayleigh peak and Raman sidebands are investigated systematically for various trap conditions.

  6. Measurement of the trapping lifetime close to a cold metallic surface on a cryogenic atom-chip

    CERN Document Server

    Emmert, Andreas; Nogues, Gilles; Brune, Michel; Raimond, Jean-Michel; Haroche, Serge

    2009-01-01

    We have measured the trapping lifetime of magnetically trapped atoms in a cryogenic atom-chip experiment. An ultracold atomic cloud is kept at a fixed distance from a thin gold layer deposited on top of a superconducting trapping wire. The lifetime is studied as a function of the distances to the surface and to the wire. Different regimes are observed, where loss rate is determined either by the technical current noise in the wire or the Johnson-Nyquist noise in the metallic gold layer, in good agreement with theoretical predictions. Far from the surface, we observe exceptionally long trapping times for an atom-chip, in the 10-minutes range.

  7. Observation of Entanglement of a Single Photon with a Trapped Atom

    International Nuclear Information System (INIS)

    We report the observation of entanglement between a single trapped atom and a single photon at a wavelength suitable for low-loss communication over large distances, thereby achieving a crucial step towards long range quantum networks. To verify the entanglement, we introduce a single atom state analysis. This technique is used for full state tomography of the atom-photon qubit pair. The detection efficiency and the entanglement fidelity are high enough to allow in a next step the generation of entangled atoms at large distances, ready for a final loophole-free Bell experiment

  8. Investigation of ultracold atoms and molecules in a dark magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Rong; Ji Zhong-Hua; Yuan Jin-Peng; Yang Yan; Zhao Yan-Ting; Ma Jie; Xiao Lian-Tuan; Jia Suo-Tang

    2012-01-01

    In this paper,ultracold atoms and molecules in a dark magneto-optical trap (MOT) are studied via depumping the cesium cold atoms into the dark hyperfine ground state.The collision rate is reduced to 0.45 s-1 and the density of the atoms is increased to 5.6 × 1011 cm-3 when the fractional population of the atoms in the bright hyperfine ground state is as low as 0.15.The vibrational spectra of the ultracold cesium molecules are also studied in a standard MOT and in a dark MOT separately.The experimental results are analyzed by using the perturbative quantum approach.

  9. Entangled Radiation through an Atomic Reservoir Controlled by Coherent Population Trapping

    Institute of Scientific and Technical Information of China (English)

    Li Qian; ZHONG Wen-Xue; HU Xiang-Ming

    2008-01-01

    We show that it is possible to generate Einstein-Podolsky-Rosen (EPR) entangled radiation using an atomic reservoir controlled by coherent population trapping. A beam of three-level atoms is initially prepared in nearcoherent population trapping (CPT) state and acts as a long-lived coherence-controlled reservoir. Four-wave mixing leads to amplification of cavity modes resonant with Rabi sidebands of the atomic dipole transitions. The cavity modes evolve into an EPR state, whose degree of entanglement is controlled by the intensities and the frequencies of the driving fields. This scheme uses the long-lived CPT coherence and is robust against spontaneous emission of the atomic beam. At the same time, this scheme is implemented in a one-step procedure, not in a two-step procedure as was required in Phys. Rev. Lett. 98 (2007) 240401.

  10. Search for Electric dipole moment (EDM) in laser cooled and trapped 225Ra atoms

    Science.gov (United States)

    Kalita, Mukut; Bailey, Kevin; Dietrich, Matthew; Green, John; Holt, Roy; Korsch, Wolfgang; Lu, Zheng-Tian; Lemke, Nathan; Mueller, Peter; O'Connor, Tom; Parker, Richard; Singh, Jaideep; Trimble, Will; Argonne National Laboratory Collaboration; University Of Chicago Collabration; University Of Kentucky Collaboration

    2014-05-01

    We are searching for an EDM of the diamagnetic 225Ra atom. 225Ra has nuclear spin I =1/2. Experimental sensitivity to its EDM is enhanced due to its heavy mass and the increased Schiff moment of its octupole deformed nucleus. Our experiment involves collecting laser cooled Ra atoms in a magneto-optical trap (MOT), transporting them 1 meter with a far off-resonant optical dipole trap (ODT) and then transferring the atoms to a second standing-wave ODT in our experimental chamber. We will report our recent experiences in polarizing and observing Larmor precession of 225Ra atoms in parallel electric and magnetic fields in a magnetically shielded region and progress towards a first measurement of the EDM of 225Ra. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357 and contract No. DE-FG02-99ER41101.

  11. A compact microchip atomic clock based on all-optical interrogation of ultra-cold trapped Rb atoms

    Science.gov (United States)

    Farkas, D. M.; Zozulya, A.; Anderson, D. Z.

    2010-12-01

    We propose a compact atomic clock that uses all-optical interrogation of ultra-cold Rb atoms that are magnetically trapped near the surface of an atom microchip. The interrogation scheme, which combines electromagnetically induced transparency with Ramsey's method of separated oscillatory fields, can achieve an atomic shot-noise-level performance better than 10^{-13}/sqrt{tau} for 106 atoms. A two-color Mach-Zehnder interferometer can detect a 100-pW probe beam at the optical shot-noise level using conventional photodetectors. This measurement scheme is nondestructive and therefore can be used to increase the operational duty cycle by reusing the trapped atoms for multiple clock cycles. Numerical calculations of the density matrix equations are used to identify realistic operating parameters at which AC Stark shifts are eliminated. By considering fluctuations in these parameters, we estimate that AC Stark shifts can be canceled to a level better than 2×10-14. An overview of the apparatus is presented with estimates of cycle time and power consumption.

  12. Laser cooling of single trapped atoms to the ground state: a dark state in position space

    OpenAIRE

    Morigi, Giovanna; Cirac Sasturáin, Juan Ignacio,; Ellinger, K; Zoller, P.

    1997-01-01

    We propose a scheme that allows us to laser cool trapped atoms to the ground state of a one-dimensional confining potential. The scheme is based on the creation of a dark state by designing the laser profile, so that the hottest atoms are coherently pumped to another internal level, and then repumped back. The scheme works beyond the Lamb-Dicke limit. We present results of a full quantum treatment for a one-dimensional model.

  13. Direct Observation of Coherent Population Trapping in a Superconducting Artificial Atom

    OpenAIRE

    Kelly, William R.; Dutton, Zachary; Schlafer, John; Mookerji, Bhaskar; Ohki, Thomas A.; Kline, Jeffrey S.; Pappas, David P.

    2009-01-01

    The phenomenon of Coherent Population Trapping (CPT) of an atom (or solid state "artificial atom"), and the associated effect of Electromagnetically Induced Transparency (EIT), are clear demonstrations of quantum interference due to coherence in multi-level quantum systems. We report observation of CPT in a superconducting phase qubit by simultaneously driving two coherent transitions in a $\\Lambda$-type configuration, utilizing the three lowest lying levels of a local minimum of a phase qubi...

  14. Atomic scale imaging and spectroscopy of individual electron trap states using force detected dynamic tunnelling

    International Nuclear Information System (INIS)

    We report the first atomic scale imaging and spectroscopic measurements of electron trap states in completely non-conducting surfaces by dynamic tunnelling force microscopy/spectroscopy. Single electrons are dynamically shuttled to/from individual states in thick films of hafnium silicate and silicon dioxide. The new method opens up surfaces that are inaccessible to the scanning tunnelling microscope for imaging and spectroscopy on an atomic scale.

  15. Preparation of Bose Einstein condensates in realistc trapping potentials for precision atom interferometry

    Science.gov (United States)

    Posso Trujillo, Katerine; Rasel, Ernst M.; Gaaloul, Naceur; Quantus Team

    Preparation of Bose Einstein condensates in realistc trapping potentials for precision atom interferometry Theoretical studies of the ground state and the dynamical properties of Bose Einstein condensates (BECs) are typically realized by considering the ensemble as being initiaally trapped by a harmonic potential. Dramatic discrepancies were found by comparing numerical results of the long-time expansion of BECs after being released from the harmonic trap, and measurements of the free evolution and delta-kick cooling (DKC) of a 87Rb BEC on large timescales of up to 2 s in micro-gravity (micro-g) environment such as those performed in the QUANTUS project from our group. The modification in the dynamics of a 87Rb BEC with the application of DKC by using experimentally implemented trapping geometries and the effect of gravity have been studied. Three different configurations have been considered: atom chip-based potential, dipole trap and the time-averaged orbiting potential. Such discrepancies may be crucial in high precision atom interferometry experiments in micro-g and zero-g platforms in which the implementation of DKC is mandatory to achieve the long-expansion times required

  16. Optimizing the production of metastable calcium atoms in a magneto-optical trap

    CERN Document Server

    Gruenert, J; Gruenert, Jan; Hemmerich, Andreas

    2001-01-01

    We investigate the production of long lived metastable (3P2, n=4) calcium atoms in a magneto-optical trap operating on the 1S0 to 1P1 transition at 423 nm. For excited 1P1-atoms a weak decay channel into the triplet states 3P2 and 3P1 exists via the singlet 1D2 (n=3) state. The undesired 3P1-atoms decay back to the ground state within 0.4 ms and can be fully recaptured if the illuminated trap volume is sufficiently large. We obtain a flux of above 10^10 atoms/s into the 3P2-state. We find that our MOT life time of 23 ms is mainly limited by this loss channel and thus the 3P2-production is not hampered by inelasic collisions. If we close the loss channel by repumping the 1D2-atoms with a 671 nm laser back into the MOT cycling transition, a non-exponential 72 ms trap decay is observed indicating the presence of inelastic two-body collisions between 1S0 and 1P1 atoms.

  17. Coherence of a qubit stored in Zeeman levels of a single optically trapped atom

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfeld, Wenjamin; Weinfurter, Harald [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, D-80799 Muenchen (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Volz, Juergen; Weber, Markus [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, D-80799 Muenchen (Germany)

    2011-08-15

    We experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 5{sup 2}S{sub 1/2}, F=1 hyperfine ground level of a single optically trapped {sup 87}Rb atom. Larmor precession of a single atomic spin-1 system is observed by preparing the atom in a defined initial spin state and then measuring the resulting state after a programmable period of free evolution. Additionally, by performing quantum-state tomography, maximum knowledge about the spin coherence is gathered. By using an active magnetic field stabilization and without application of a magnetic guiding field, we achieve transverse and longitudinal dephasing times of T{sub 2}{sup *}=75-150 {mu}s and T{sub 1}>0.5 ms, respectively. We derive the light-shift distribution of a single atom in the approximately harmonic potential of a dipole trap and show that the measured atomic spin coherence is limited mainly by residual position- and state-dependent effects in the optical trapping potential. The improved understanding enables longer coherence times, an important prerequisite for future applications in long-distance quantum communication and computation with atoms in optical lattices, or for a loophole-free test of Bell's inequality.

  18. Hydride generation – in-atomizer collection of Pb in a quartz trap-and-atomizer device for atomic absorption spectrometry – an interference study

    Energy Technology Data Exchange (ETDEWEB)

    Novotný, Pavel [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); High School in Hořice, Husova 1414, 508 01 Hořice (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic)

    2013-01-01

    Interferences of selected hydride forming elements (As, Sb, Bi, Se and Sn) on lead determination by hydride generation atomic absorption spectrometry were extensively studied in both on-line atomization and preconcentration (collection) modes. The commonly used on-line atomization mode was found free of significant interferences, whereas strong interference from Bi was observed when employing the preconcentration mode with plumbane collection in a quartz trap-and-atomizer device. Interference of Bi seems to take place in the preconcentration step. Interference of Bi in the collection mode cannot be reduced by increased hydrogen radical amount in the trap and/or the atomizer. - Highlights: ► Interference study on Pb determination by in-atomizer trapping was performed for the first time. ► Bi was found as a severe interferent in the preconcentration mode (Pb:Bi ratio 1:100). ► No interference was found in the on-line atomization (no preconcentration). ► Bi interference occurs during preconcentration.

  19. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    OpenAIRE

    Abdollahi Atousa; Amirkavehei Mooud; Gheisari Mohammad Mehdi; Tadayon Fariba

    2014-01-01

    A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap). The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS). The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically ...

  20. Production of antihydrogen at reduced magnetic field for anti-atom trapping

    CERN Document Server

    Andresen, G B; Boston, A; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Chartier, M; Deutsch, A; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Gomberoff, K; Hangst, J S; Hayano, R S; Hydomako, R; Jenkins, M J; Jørgensen, L V; Kurchaninov, L; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page, R D; Povilus, A; Robicheaux, F; Sarid, E; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    We have demonstrated production of antihydrogen in a 1$,$T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3$,$T) and ATRAP (5$,$T). The motivation for using a smaller magnetic field is to facilitate trapping of antihydrogen atoms in a neutral atom trap surrounding the production region. We report the results of measurements with the ALPHA (Antihydrogen Laser PHysics Apparatus) device, which can capture and cool antiprotons at 3$,$T, and then mix the antiprotons with positrons at 1$,$T. We infer antihydrogen production from the time structure of antiproton annihilations during mixing, using mixing with heated positrons as the null experiment, as demonstrated in ATHENA. Implications for antihydrogen trapping are discussed.

  1. Breakdown of Atomic Hyperfine Coupling in a Deep Optical-Dipole Trap

    CERN Document Server

    Neuzner, Andreas; Dürr, Stephan; Rempe, Gerhard; Ritter, Stephan

    2015-01-01

    We experimentally study the breakdown of hyperfine coupling for an atom in a deep optical-dipole trap. One-color laser spectroscopy is performed at the resonance lines of a single $^{87}$Rb atom for a trap wavelength of 1064 nm. Evidence of hyperfine breakdown comes from three observations, namely a nonlinear dependence of the transition frequencies on the trap intensity, a splitting of lines which are degenerate for small intensities, and the ability to drive transitions which would be forbidden by selection rules in the absence of hyperfine breakdown. From the data, we infer the hyperfine interval of the $5P_{1/2}$ state and the scalar and tensor polarizabilities for the $5P_{3/2}$ state.

  2. Quantum phases and dynamics of bosonic atoms trapped in a single-mode optical cavity

    Science.gov (United States)

    Sundar, Bhuvanesh; Mueller, Erich

    2016-05-01

    Motivated by experiments performed by R. Landig et al. (arXiv:1511.00007), we theoretically explore the behavior of bosonic atoms trapped in a single-mode cavity in the presence of a two-dimensional optical lattice. As explained by arXiv:1511.00007, Rayleigh scattering of light from the lattice-inducing beams into the cavity produces infinite-range cavity-mediated interactions between the atoms, leading to competition between superfluid, supersolid, Mott insulating and charge density wave phases. We calculate the phase diagram for a uniform trap using a variation of the Gutzwiller Ansatz. We also calculate the spatial distribution of the different phases in the gas in the presence of a harmonic trap. We explore hysteretic behavior when parameters of the system are changed.

  3. Trapping and cooling of sodium atoms for assembly of dipolar molecules

    Science.gov (United States)

    Yu, Yichao; Hutzler, Nicholas R.; Liu, Lee R.; Zhang, Jessie T.; Ni, Kang-Kuen

    2016-05-01

    In order to create a diatomic molecule with a large electric dipole moment, it is generally necessary to use atoms with very different electronegativities. In the context of bi-alkali molecules, this means combining a light alkali atom with a heavy one. This is the reason why we use NaCs in our molecule assembler experiment; NaCs has the largest induced dipole moment in few kV/cm lab fields. However, the use of sodium atoms also poses challenges. The higher Doppler temperature and lack of efficient D2 polarization gradient cooling increases the necessary depth of our optical dipole (tweezer) traps. The lack of a convenient magic wavelength for the dipole trap creates a large AC stark shift on the optical transition as well as additional heating mechanisms. The light mass of the sodium, and therefore larger Lamb-Dicke parameter and higher recoil temperature, makes it more difficult to perform efficient Raman sideband cooling on the atom in the trap. I will discuss the techniques we use to overcome these challenges, in particular a method to eliminate the light shifts and associated heating mechanisms in tight optical traps.

  4. Measuring isospin mixing in sup 3 sup 6 Ar using a polarized, neutral atom trap

    CERN Document Server

    Melconian, D; Ball, G; Behr, J A; Bricault, P G; Brown, B A; Dombsky, M; Jackson, K P; Fostner, S; Gorelov, A; Groves, M N; Gu, S; Pearson, M R; Towner, I S; Trinczek, M; Vollrath, I

    2003-01-01

    Magneto-optical traps provide a cold, compact cloud of radioactive atoms and therefore are an ideal source for use in precision nuclear beta decay studies. Optical pumping techniques can add a new dimension to such experiments by efficiently polarizing these samples to 0 sup + decays.

  5. Intrinsic electron traps in atomic-layer deposited HfO2 insulators

    Science.gov (United States)

    Cerbu, F.; Madia, O.; Andreev, D. V.; Fadida, S.; Eizenberg, M.; Breuil, L.; Lisoni, J. G.; Kittl, J. A.; Strand, J.; Shluger, A. L.; Afanas'ev, V. V.; Houssa, M.; Stesmans, A.

    2016-05-01

    Analysis of photodepopulation of electron traps in HfO2 films grown by atomic layer deposition is shown to provide the trap energy distribution across the entire oxide bandgap. The presence is revealed of two kinds of deep electron traps energetically distributed at around Et ≈ 2.0 eV and Et ≈ 3.0 eV below the oxide conduction band. Comparison of the trapped electron energy distributions in HfO2 layers prepared using different precursors or subjected to thermal treatment suggests that these centers are intrinsic in origin. However, the common assumption that these would implicate O vacancies cannot explain the charging behavior of HfO2, suggesting that alternative defect models should be considered.

  6. Trapping of Weak Signal Pulses by Soliton and Trajectory Control in a Coherent Atomic Gas

    CERN Document Server

    Chen, Zhiming

    2016-01-01

    We propose a method for trapping weak signal pulses by soliton and realizing its trajectory control via electromagnetically induced transparency (EIT). The system we consider is a cold, coherent atomic gas with a tripod or multipod level configuration. We show that, due to the giant enhancement of Kerr nonlinearity contributed by EIT, several weak signal pulses can be effectively trapped by a soliton and cotravel stably with ultraslow propagating velocity. Furthermore, we demonstrate that the trajectories of the soliton and the trapped signal pulses can be manipulated by using a Stern-Gerlach gradient magnetic field. As a result, the soliton and the trapped signal pulses display a Stern-Gerlach deflection and both of them can bypass an obstacle together. The results predicted here may be used to design all-optical switching at very low light level.

  7. Planar Atom Trap and Magnetic Resonance 'Lens' Designs

    CERN Document Server

    Barbic, M; Emery, T H; Scherer, A

    2007-01-01

    We present various planar magnetic designs that create points above the plane where the magnitude of the static magnetic field is a local minimum. Structures with these properties are of interest in the disciplines of neutral atom confinement, magnetic levitation, and magnetic resonance imaging. Each planar permanent magnet design is accompanied by the equivalent planar single non-crossing conductor design. Presented designs fall into three categories producing: a) zero value magnetic field magnitude point minima, b) non-zero magnetic field magnitude point minima requiring external bias magnetic field, and c) self-biased non-zero magnetic field magnitude point minima. We also introduce the Principle of Amperean Current Doubling in planar perpendicularly magnetized thin films that can be used to improve the performance of each permanent magnet design we present. Single conductor current-carrying designs are suitable for single layer lithographic fabrication, as we experimentally demonstrate. Finally, we presen...

  8. Temperature and phase-space density of a cold atom cloud in a quadrupole magnetic trap

    Energy Technology Data Exchange (ETDEWEB)

    Ram, S. P.; Mishra, S. R.; Tiwari, S. K.; Rawat, H. S. [Raja Ramanna Centre for Advanced Technology, Indore (India)

    2014-08-15

    We present studies on modifications in the temperature, number density and phase-space density when a laser-cooled atom cloud from optical molasses is trapped in a quadrupole magnetic trap. Theoretically, for a given temperature and size of the cloud from the molasses, the phase-space density in the magnetic trap is shown first to increase with increasing magnetic field gradient and then to decrease with it after attaining a maximum value at an optimum value of the magnetic-field gradient. The experimentally-measured variation in the phase-space density in the magnetic trap with changing magnetic field gradient is shown to exhibit a similar trend. However, the experimentally-measured values of the number density and the phase-space density are much lower than the theoretically-predicted values. This is attributed to the experimentally-observed temperature in the magnetic trap being higher than the theoretically-predicted temperature. Nevertheless, these studies can be useful for setting a higher phase-space density in the trap by establishing an optimal value of the field gradient for a quadrupole magnetic trap.

  9. Entanglement Preparation and Quantum Information Processing with Atoms Trapped in Separated Cavities Through a Single Resonant Atom-Field Interaction

    Science.gov (United States)

    Lin, Li-Hua

    2014-01-01

    In this paper, a scheme is presented for generation of W-type entangled states for n atoms trapped in separated cavities connected by optical fibers. The scheme only requires a single atom-cavity-fiber interaction and no classical field is needed. Due to these features, the scheme is simpler and more robust against decoherence than the previous ones. The scheme can also be used to realize quantum state transfer and controlled phase gates between qubits located at distant nodes of a quantum network.

  10. Azimuthal Sisyphus effect for atoms in a toroidal all-optical trap

    Energy Technology Data Exchange (ETDEWEB)

    Lembessis, V. E. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Ellinas, D. [Technical University of Crete, Department of Sciences M PHI Q Research Unit GR-731 00 Chania, Crete (Greece); Babiker, M. [Department of Physics, University of York, Heslington, York YO10 5DD, England (United Kingdom)

    2011-10-15

    It is shown that an optical arrangement in which two identical counterpropagating Laguerre-Gaussian doughnut beams LG(l,0) and LG(-l,0) with orthogonal linear polarizations e {sub x} and e {sub y} can lead to azimuthal polarization gradients and an as yet undiscovered azimuthal Sisyphus effect. It is demonstrated that this effect can be utilized in the creation and control of a persistent current of superfluid atoms circulating in a toroidal trap. Such a physical system has recently been highlighted as the basis for an atomic superconducting quantum interference device (SQUID) and ultimately for the realization of atom circuits.

  11. Spectroscopy, Manipulation and Trapping of Neutral Atoms, Molecules, and Other Particles using Optical Nanofibers: A Review

    CERN Document Server

    Morrissey, Michael J; Frawley, Mary; Kumar, Ravi; Prel, Eugen; Russell, Laura; Truong, Viet Giang; Chormaic, Síle Nic

    2013-01-01

    The use of tapered optical fibers, i.e., optical nanofibers, for spectroscopy and the detection of small numbers of particles, such as neutral atoms or molecules, has been gaining ground in recent years. In this review, we briefly introduce the optical nanofiber, its fabrication and optical mode propagation within. We discuss recent progress on the integration of optical nanofibers into laser-cooled atom and vapor systems, paying particular attention to spectroscopy, cold atom cloud characterization and optical trapping schemes. Next, a natural extension on this work to molecules will be introduced. Finally, we consider several alternatives to optical nanofibers that display some advantages for particular applications.

  12. Coherence of a qubit stored in Zeeman levels of a single optically trapped atom

    CERN Document Server

    Rosenfeld, Wenjamin; Weber, Markus; Weinfurter, Harald

    2011-01-01

    We experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 5S1/2, F=1 hyperfine ground level of a single optically trapped Rb-87 atom. Larmor precession of a single atomic spin-1 system is observed by preparing the atom in a defined initial spin-state and then measuring the resulting state after a programmable period of free evolution. Additionally, by performing quantum state tomography, maximum knowledge about the spin coherence is gathered. By using an active magnetic field stabilization and without application of a magnetic guiding field we achieve transverse and longitudinal dephasing times of T2*=75..150 \\mus and T1>0.5 ms respectively. We derive the light-shift distribution of a single atom in the approximately harmonic potential of a dipole trap and show that the measured atomic spin coherence is limited mainly by residual position- and state-dependent effects in the optical trapping potential. The improved understanding enables longer coherence times, an i...

  13. Inductively coupled plasma-atomic emission spectroscopy: The determination of trace impurities in uranium hexafluoride

    Science.gov (United States)

    Floyd, M. A.; Morrow, R. W.; Farrar, R. B.

    An analytical method has been developed for the determination of trace impurities in high-purity uranium hexafluoride using liquid-liquid extraction of the uranium from the trace impurities followed by analysis with inductively coupled plasma-atomic emission spectroscopy. Detection limits, accuracy, and precision data are presented.

  14. Transport of ultracold atoms between concentric traps via spatial adiabatic passage

    CERN Document Server

    Polo, Joan; Busch, Thomas; Ahufinger, Verònica; Mompart, Jordi

    2015-01-01

    Spatial adiabatic passage processes for ultracold atoms trapped in tunnel-coupled cylindrically symmetric concentric potentials are investigated. Specifically, we discuss the matter-wave analogue of the rapid adiabatic passage (RAP) technique for a high fidelity and robust loading of a single atom into a harmonic ring potential from a harmonic trap, and for its transport between two concentric rings. We also consider a system of three concentric rings and investigate the transport of a single atom between the innermost and the outermost rings making use of the matter-wave analogue of the stimulated Raman adiabatic passage (STIRAP) technique. We describe the RAP-like and STIRAP-like dynamics by means of a two- and a three-state models, respectively, obtaining good agreement with the numerical simulations of the corresponding two-dimensional Schr\\"odinger equation.

  15. Electrostatic trapping and in situ detection of Rydberg atoms above chip-based transmission lines

    CERN Document Server

    Lancuba, P

    2016-01-01

    Beams of helium atoms in Rydberg-Stark states with principal quantum number $n=48$ and electric dipole moments of 4600~D have been decelerated from a mean initial longitudinal speed of 2000~m/s to zero velocity in the laboratory-fixed frame-of-reference in the continuously moving electric traps of a transmission-line decelerator. In this process accelerations up to $-1.3\\times10^{7}$~m/s$^2$ were applied, and changes in kinetic energy of $\\Delta E_{\\mathrm{kin}}=1.3\\times10^{-20}$~J ($\\Delta E_{\\mathrm{kin}}/e = 83$~meV) per atom were achieved. Guided and decelerated atoms, and those confined in stationary electrostatic traps, were detected in situ by pulsed electric field ionisation. The results of numerical calculations of particle trajectories within the decelerator have been used to characterise the observed deceleration efficiencies, and aid in the interpretation of the experimental data.

  16. Improved atom number with a dual color magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Cao Qiang; Luo Xin-Yu; Gao Kui-Yi; Wang Xiao-Rui; Chen Dong-Min; Wang Ru-Quan

    2012-01-01

    We demonstrate a novel dual color magneto-optical trap (MOT),which uses two sets of overlapping laser beams to cool and trap 87Rb atoms.The volume of cold cloud in the dual color MOT is strongly dependent on the frequency difference of the laser beams and can be significantly larger than that in the normal MOT with single frequency MOT beams.Our experiment shows that the dual color MOT has the same loading rate as the normal MOT,but much longer loading time,leading to threefold increase in the number of trapped atoms.This indicates that the larger number is caused by reduced light induced loss.The dual color MOT is very useful in experiments where both high vacuum level and large atom number are required,such as single chamber quantum memory and Bose Einstein condensation (BEC) experiments.Compared to the popular dark spontaneous-force optical trap (dark SPOT) technique,our approach is technically simpler and more suitable to low power laser systems.

  17. Absorption spectroscopy of cold caesium atoms confined in a magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Yan Shu-Bin; Liu Tao; Geng Tao; Zhang Tian-Cai; Peng Kun-Chi; Wang Jun-Min

    2004-01-01

    Absorption spectra of cold caesium atoms confined in a magneto-optical trap are measured around D2 line at 852nm with a weak probe beam. Absorption reduction dip due to electromagnetically induced transparency (EIT)effect induced by the cooling/trapping field in a V-type three-level system and a gain peak near the cycling transition are clearly observed. Several mechanisms mixed with EIT effect in a normal V-type three-level system are briefly discussed. A simple theoretical analysis based on a dressed-state model is presented for interpretation of the absorption spectra.

  18. Influence of trapping potentials on the phase diagram of bosonic atoms in optical lattices

    International Nuclear Information System (INIS)

    We study the effect of external trapping potentials on the phase diagram of bosonic atoms in optical lattices. We introduce a generalized Bose-Hubbard Hamiltonian that includes the structure of the energy levels of the trapping potential, and show that these levels are in general populated both at finite and zero temperature. We characterize the properties of the superfluid transition for this situation and compare them with those of the standard Bose-Hubbard description. We briefly discuss similar behaviors for fermionic systems

  19. Temperature and phase-space density of cold atom cloud in a quadrupole magnetic trap

    CERN Document Server

    Ram, S P; Tiwari, S K; Rawat, H S

    2014-01-01

    We present studies on the modifications in temperature, number density and phase-space density when a laser cooled atom cloud from the optical molasses is trapped in a quadrupole magnetic trap. Theoretically it is shown that for a given temperature and size of the cloud from the molasses, the phase-space density in the magnetic trap first increases with magnetic field gradient and then decreases with it, after attaining a maximum value at an optimum value of magnetic field gradient. The experimentally measured variation in phase-space density in the magnetic trap with the magnetic field gradient has shown the similar trend. However, the experimentally measured values of number density and phase-space density are much lower than their theoretically predicted values. This is attributed to the higher experimentally observed temperature in the magnetic trap than the theoretically predicted temperature. Nevertheless, these studies can be useful to set a higher phase-space density in the trap by setting the optimum...

  20. On the combination of a low energy hydrogen atom beam with a cold multipole ion trap

    International Nuclear Information System (INIS)

    The first part of the activities of this thesis was to develop a sophisticated ion storage apparatus dedicated to study chemical processes with atomic hydrogen. The integration of a differentially pumped radical beam source into an existing temperature variable 22- pole trapping machine has required major modifications. Since astrophysical questions have been in the center of our interest, the introduction first gives a short overview of astrophysics and -chemistry. The basics of ion trapping in temperature variable rf traps is well-documented in the literature; therefore, the description of the basic instrument (Chapter 2) is kept rather short. Much effort has been put into the development of an intense and stable source for hydrogen atoms the kinetic energy of which can be changed. Chapter 3 describes this module in detail with emphasis on the integration of magnetic hexapoles for guiding the atoms and special treatments of the surfaces for reducing H-H recombination. Due to the unique sensitivity of the rf ion trapping technique, this instrument allows one to study a variety of reactions of astrochemical and fundamental interest. The results of this work are summarized in Chapter 4. Reactions of CO2+ with hydrogen atoms and molecules have been established as calibration standard for in situ determination of H and H2 densities over the full temperature range of the apparatus (10 K-300 K). For the first time, reactions of H- and D-atoms with the ionic hydrocarbons CH+, CH2+, and CH4+ have been studied at temperatures of interstellar space. A very interesting, not yet fully understood collision system is the interaction of protonated methane with H. The outlook presents some ideas, how to improve the new instrument and a few reaction systems are mentioned which may be studied next. (orig.)

  1. On the combination of a low energy hydrogen atom beam with a cold multipole ion trap

    Energy Technology Data Exchange (ETDEWEB)

    Borodi, Gheorghe

    2008-12-09

    The first part of the activities of this thesis was to develop a sophisticated ion storage apparatus dedicated to study chemical processes with atomic hydrogen. The integration of a differentially pumped radical beam source into an existing temperature variable 22- pole trapping machine has required major modifications. Since astrophysical questions have been in the center of our interest, the introduction first gives a short overview of astrophysics and -chemistry. The basics of ion trapping in temperature variable rf traps is well-documented in the literature; therefore, the description of the basic instrument (Chapter 2) is kept rather short. Much effort has been put into the development of an intense and stable source for hydrogen atoms the kinetic energy of which can be changed. Chapter 3 describes this module in detail with emphasis on the integration of magnetic hexapoles for guiding the atoms and special treatments of the surfaces for reducing H-H recombination. Due to the unique sensitivity of the rf ion trapping technique, this instrument allows one to study a variety of reactions of astrochemical and fundamental interest. The results of this work are summarized in Chapter 4. Reactions of CO{sub 2}{sup +} with hydrogen atoms and molecules have been established as calibration standard for in situ determination of H and H{sub 2} densities over the full temperature range of the apparatus (10 K-300 K). For the first time, reactions of H- and D-atoms with the ionic hydrocarbons CH{sup +}, CH{sub 2}{sup +}, and CH{sub 4}{sup +} have been studied at temperatures of interstellar space. A very interesting, not yet fully understood collision system is the interaction of protonated methane with H. The outlook presents some ideas, how to improve the new instrument and a few reaction systems are mentioned which may be studied next. (orig.)

  2. Trapping of atomic hydrogen in octasilsesquioxane cages by glow discharge treatment

    International Nuclear Information System (INIS)

    Hydrogen atoms are trapped in octasilsesquioxane ((RSiO3/2)8, R = H, CH3, i-butyl, etc.) cages by electric discharge treatment. The yield of the trapped hydrogen was evaluated to be 1.3 x 10-4 of cage unit by using ESR spectroscopy for (CH3SiO3/2)8 discharged for 4 minutes at room temperature. To obtain a comparable yield of the trapped hydrogen by γ-rays (60Co) irradiation, an absorbed dose of ca. 300 kGy is required, taking two days or more in general. The discharge technique is simple and extremely efficient compared to the conventional method of γ-ray radiolysis. (author)

  3. Magneto-Optical Trapping of 88Sr atoms with 689 nm Laser

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; LIN Bai-Ke; ZHAO Yang; LI Ye; WANG Shao-Kai; WANG Min-Ming; ZANG Er-Jun; LI Tian-Chu; FANG Zhan-Jun

    2011-01-01

    We report the experimental realization of strontium magneto-optical trap(MOT) operating on the intercombination transition lSo-3 P1 at 689nm, namely red MOT. A 689nm laser used for cooling and trapping is injection locked to a master laser, whose linewidth is narrowed to 150 Hz by locking to a high finesse optical reference cavity.88 Sr atoms pre-cooled and trapped by the broad 1SO-1 Pl transition at 461 nm are transferred to the red MOT with the help of a time sequence controller. The transfer ratio is about 20% and the red MOT's temperature is estimated to be less than 20 μK by the time-of-flight(TOF) image analysis.

  4. Optical trapping of cold neutral atoms using a two-color evanescent light field around a carbon nanotube

    International Nuclear Information System (INIS)

    We suggest a new schema of trapping cold atoms using a two-color evanescent light field around a carbon nanotube. The two light fields circularly polarized sending through a carbon nanotube generates an evanescent wave around this nanotube. By evanescent effect, the wave decays away from the nanotube producing a set of trapping minima of the total potential in the transverse plane as a ring around the nanotube. This schema allows capture of atoms to a cylindrical shell around the nanotube. We consider some possible boundary conditions leading to the non-trivial bound state solution. Our result will be compared to some recent trapping models and our previous trapping models.

  5. Developing Density of Laser-Cooled Neutral Atoms and Molecules in a Linear Magnetic Trap

    Science.gov (United States)

    Velasquez, Joe, III; Walstrom, Peter; di Rosa, Michael

    2013-05-01

    In this poster we show that neutral particle injection and accumulation using laser-induced spin flips may be used to form dense ensembles of ultracold magnetic particles, i.e., laser-cooled paramagnetic atoms and molecules. Particles are injected in a field-seeking state, are switched by optical pumping to a field-repelled state, and are stored in the minimum-B trap. The analogous process in high-energy charged-particle accumulator rings is charge-exchange injection using stripper foils. The trap is a linear array of sextupoles capped by solenoids. Particle-tracking calculations and design of our linear accumulator along with related experiments involving 7Li will be presented. We test these concepts first with atoms in preparation for later work with selected molecules. Finally, we present our preliminary results with CaH, our candidate molecule for laser cooling. This project is funded by the LDRD program of Los Alamos National Laboratory.

  6. Narrow-line magneto-optical cooling and trapping of strongly magnetic atoms

    CERN Document Server

    Berglund, Andrew J; McClelland, Jabez J

    2008-01-01

    Laser cooling on weak transitions is a useful technique for reaching ultracold temperatures in atoms with multiple valence electrons. However, for strongly magnetic atoms a conventional narrow-line magneto-optical trap (MOT) is destabilized by competition between optical and magnetic forces. We overcome this difficulty in Er by developing an unusual narrow-line MOT that balances optical and magnetic forces using laser light tuned to the blue side of a narrow (8 kHz) transition. The trap population is spin-polarized with temperatures reaching below 2 microkelvin. Our results constitute an alternative method for laser cooling on weak transitions, applicable to rare-earth-metal and metastable alkaline earth elements.

  7. Microfabricated cells for chip-scale atomic clock based on coherent population trapping: Fabrication and investigation

    Directory of Open Access Journals (Sweden)

    S.V. Ermak

    2015-03-01

    Full Text Available A universal method for fabrication of miniature cells for frequency standards and quantum magnetometers containing 87Rb atoms in the atmosphere of inert gas neon based on integrated technologies is considered. The results of experimental studies of coherent population trapping signals observed for a series of cells which provided recovery of vapors of an alkali metal from the rubidium dichromate salt with the help of laser radiation are presented. The coherent population trapping signals with a typical linewidth of 2–3 kHz and a signal-to-noise ratio of 1500 in the 1-Hz bandwidth were observed, which allows one to provide a relative frequency stability of atomic clock of 10−11 at 100 s.

  8. Generation of a cold pulsed beam of Rb atoms by transfer from a 3D magneto-optic trap

    CERN Document Server

    Chanu, Sapam Ranjita; Natarajan, Vasant

    2016-01-01

    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.

  9. Generation of a cold pulsed beam of Rb atoms by transfer from a 3D magneto-optic trap

    Science.gov (United States)

    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.

  10. High-Resolution Imaging and Optical Control of Bose-Einstein Condensates in an Atom Chip Magnetic Trap

    CERN Document Server

    Salim, Evan A; Pfeiffer, Jonathan B; Anderson, Dana Z

    2012-01-01

    A high-resolution projection and imaging system for ultracold atoms is implemented using a compound silicon and glass atom chip. The atom chip is metalized to enable magnetic trapping while glass regions enable high numerical aperture optical access to atoms residing in the magnetic trap about 100 microns below the chip surface. The atom chip serves as a wall of the vacuum system, which enables the use of commercial microscope components for projection and imaging. Holographically generated light patterns are used to optically slice a cigar-shaped magnetic trap into separate regions; this has been used to simultaneously generate up to four Bose-condensates. Using fluorescence techniques we have demonstrated in-trap imaging resolution down to 2.5 microns

  11. Highly collimated source of cold Rubidium atoms from a two dimensional magneto-optical trap

    CERN Document Server

    Carrat, Vincent; Jacquey, Marion; Tabosa, José W; de Lesegno, Bruno Viaris; Pruvost, Laurence

    2013-01-01

    Using a blue detuned laser shaped in a Laguerre-Gaussian donut mode we highly collimate the output of a two dimensional magneto-optical trap. The resulting atomic beam has a 1 mm diameter, its divergence is reduced from 40 down to 3 mrad and the atomic density is increased by a factor of 200. The collimation effect has been studied versus the order of the Laguerre-Gaussian mode (up to 10) and the laser atom frequency detuning (2 to 120 GHz). The 2D-colli-MOT study allows us to determine the best conditions which minimize the atom heating due to residual light absorption and optimize the collimation effect. The 2D-colli MOT could provide a new tool to fill a 3D-MOT using lasers with millimeter range diameters and thus sparing the laser power.

  12. Forbidden atomic transitions driven by an intensity-modulated laser trap.

    Science.gov (United States)

    Moore, Kaitlin R; Anderson, Sarah E; Raithel, Georg

    2015-01-20

    Spectroscopy is an essential tool in understanding and manipulating quantum systems, such as atoms and molecules. The model describing spectroscopy includes the multipole-field interaction, which leads to established spectroscopic selection rules, and an interaction that is quadratic in the field, which is not often employed. However, spectroscopy using the quadratic (ponderomotive) interaction promises two significant advantages over spectroscopy using the multipole-field interaction: flexible transition rules and vastly improved spatial addressability of the quantum system. Here we demonstrate ponderomotive spectroscopy by using optical-lattice-trapped Rydberg atoms, pulsating the lattice light and driving a microwave atomic transition that would otherwise be forbidden by established spectroscopic selection rules. This ability to measure frequencies of previously inaccessible transitions makes possible improved determinations of atomic characteristics and constants underlying physics. The spatial resolution of ponderomotive spectroscopy is orders of magnitude better than the transition frequency would suggest, promising single-site addressability in dense particle arrays for quantum computing applications.

  13. Forbidden atomic transitions driven by an intensity-modulated laser trap

    CERN Document Server

    Moore, Kaitlin R; Raithel, Georg

    2014-01-01

    Spectroscopy is an essential tool in understanding and manipulating quantum systems, such as atoms and molecules. The model describing spectroscopy includes a multipole-field interaction, which leads to established spectroscopic selection rules, and an interaction that is quadratic in the field, which is often neglected. However, spectroscopy using the quadratic (ponderomotive) interaction promises two significant advantages over spectroscopy using the multipole-field interaction: flexible transition rules and vastly improved spatial addressability of the quantum system. For the first time, we demonstrate ponderomotive spectroscopy by using optical-lattice-trapped Rydberg atoms, pulsating the lattice light at a microwave frequency, and driving a microwave atomic transition that would otherwise be forbidden by established spectroscopic selection rules. This new ability to measure frequencies of previously inaccessible transitions makes possible improved determinations of atomic characteristics and constants un...

  14. Nanofiber-Based Double-Helix Dipole Trap for Cold Neutral Atoms

    CERN Document Server

    Reitz, D

    2012-01-01

    A double-helix optical trapping potential for cold atoms can be straightforwardly created inside the evanescent field of an optical nanofiber. It suffices to send three circularly polarized light fields through the nanofiber; two counterpropagating and far red-detuned with respect to the atomic transition and the third far blue-detuned. Assuming realistic experimental parameters, the transverse confinement of the resulting potential allows one to reach the one-dimensional regime with cesium atoms for temperatures of several \\muK. Moreover, by locally varying the nanofiber diameter, the radius and pitch of the double-helix can be modulated, thereby opening a realm of applications in cold-atom physics.

  15. Core-Shell Magneto-Optical Trap for Alkaline-Earth-Metal-Like Atoms

    CERN Document Server

    Lee, Jeongwon; Noh, Jiho; Mun, Jongchul

    2014-01-01

    We propose and demonstrate a new magneto-optical trap (MOT) for alkaline-earth-metal-like (AEML) atoms where the narrow $^{1}S_{0}\\rightarrow$$^{3}P_{1}$ transition and the broad $^{1}S_{0}\\rightarrow$$^{1}P_{1}$ transition are spatially arranged into a core-shell configuration. Our scheme resolves the main limitations of previously adopted MOT schemes, leading to a significant increase in both the loading rate and the steady state atom number. We apply this scheme to $^{174}$Yb MOT, where we show about a hundred-fold improvement in the loading rate and ten-fold improvement in the steady state atom number compared to reported cases that we know of to date. This technique could be readily extended to other AEML atoms to increase the statistical sensitivity of many different types of precision experiments.

  16. Control of light trapping in a large atomic system by a static magnetic field

    CERN Document Server

    Skipetrov, S E; Havey, M D

    2016-01-01

    We propose to control light trapping in a large ensemble of cold atoms by an external, static magnetic field. For an appropriate choice of frequency and polarization of the exciting pulse, the field is expected to speed up the fluorescence of a dilute atomic system but can significantly slow it down in a dense ensemble. The slowing down of fluorescence is due to the excitation of spatially localized collective atomic states that appear only under a strong magnetic field and have exponentially long lifetimes. The control of fluorescence by the magnetic field may be of interest for use in future quantum-information processing devices. It also paves a way towards the experimental observation of the disorder-induced localization of light in cold atomic systems.

  17. Discerning and selectively manipulating laser-trapped atoms using non-paraxial light

    CERN Document Server

    Mitsch, R; Albrecht, B; Schneeweiss, P; Rauschenbeutel, A

    2014-01-01

    We demonstrate that the non-paraxial character of a strongly confined light field can be used to spectrally discern and selectively manipulate two initially equivalent atomic ensembles of the same species. The technique is implemented with two symmetric linear arrays of cesium atoms, trapped on opposite sides of an optical nanofiber and separated by less than a micron. The nanofiber provides an evanescent field interface between the atoms and the guided light, where the latter exhibits a strongly position-dependent polarization. In the case of resonant interaction, this allows us to optically pump the ensembles into two distinct Zeeman states. In the case of dispersive interaction, the strong gradient of the light-induced fictitious magnetic field permits us to selectively address the ensembles with microwave radiation, thereby preparing them in distinct hyperfine states. This results in a composite fiber-coupled atomic medium with high potential for nonlinear optics at ultra-low light levels.

  18. A highly miniaturized vacuum package for a trapped ion atomic clock

    Science.gov (United States)

    Schwindt, Peter D. D.; Jau, Yuan-Yu; Partner, Heather; Casias, Adrian; Wagner, Adrian R.; Moorman, Matthew; Manginell, Ronald P.; Kellogg, James R.; Prestage, John D.

    2016-05-01

    We report on the development of a highly miniaturized vacuum package for use in an atomic clock utilizing trapped ytterbium-171 ions. The vacuum package is approximately 1 cm3 in size and contains a linear quadrupole RF Paul ion trap, miniature neutral Yb sources, and a non-evaporable getter pump. We describe the fabrication process for making the Yb sources and assembling the vacuum package. To prepare the vacuum package for ion trapping, it was evacuated, baked at a high temperature, and then back filled with a helium buffer gas. Once appropriate vacuum conditions were achieved in the package, it was sealed with a copper pinch-off and was subsequently pumped only by the non-evaporable getter. We demonstrated ion trapping in this vacuum package and the operation of an atomic clock, stabilizing a local oscillator to the 12.6 GHz hyperfine transition of 171Y b+. The fractional frequency stability of the clock was measured to be 2 × 10-11/τ1/2.

  19. Loading a vapor cell magneto-optic trap using light-induced atom desorption

    CERN Document Server

    Anderson, B P

    2000-01-01

    Low intensity white light was used to increase the loading rate of $^{87}$Rb atoms into a vapor cell magneto-optic trap by inducing non-thermal desorption of Rb atoms from the stainless steel walls of the vapor cell. An increased Rb partial pressure reached a new equilibrium value in less than 10 seconds after switching on the broadband light source. After the source was turned off, the partial pressure returned to its previous value in $1/e$ times as short as 10 seconds.

  20. Incomplete optical shielding in cold atom traps: three-dimensional Landau-Zener theory

    International Nuclear Information System (INIS)

    Ultracold atom collisions in the presence of a linearly polarized blueshifted laser field are studied theoretically. An analytical solution is presented within the framework of the Landau-Zener approximation. The effect of incomplete shielding is mostly accounted for by incorporating the three-dimensional character of the collisions, using a partial-wave analysis with space degeneracy. A model of two electronic states, including effects of indistinguishability of the colliding atoms, is used. The model associates the incomplete shielding with a process involving two crossing points. The theory is applied to the case of metastable xenon traps, obtaining a fair agreement with the experimental data. copyright 1997 The American Physical Society

  1. Evanescent-wave trapping and evaporative cooling of an atomic gas near two-dimensionality

    CERN Document Server

    Hammes, M; Engeser, B; Nägerl, H C; Grimm, R

    2003-01-01

    A dense gas of cesium atoms at the crossover to two-dimensionality is prepared in a highly anisotropic surface trap that is realized with two evanescent light waves. Temperatures as low as 100nK are reached with 20.000 atoms at a phase-space density close to 0.1. The lowest quantum state in the tightly confined direction is populated by more than 60%. The system offers intriguing prospects for future experiments on degenerate quantum gases in two dimensions.

  2. Optical and evaporative cooling of cesium atoms in the gravito-optical surface trap

    CERN Document Server

    Hammes, M; Druzhinina, V; Moslener, U; Manek-Hönninger, I; Grimm, R

    2000-01-01

    We report on cooling of an atomic cesium gas closely above an evanescent-wave atom mirror. At high densitities, optical cooling based on inelastic reflections is found to be limited by a density-dependent excess temperature and trap loss due to ultracold collisions involving repulsive molecular states. Nevertheless, very good starting conditions for subsequent evaporative cooling are obtained. Our first evaporation experiments show a temperature reduction from 10muK down to 300nK along with a gain in phase-space density of almost two orders of magnitude.

  3. Cavity cooling of a trapped atom using Electromagnetically-Induced Transparency

    CERN Document Server

    Bienert, Marc

    2011-01-01

    A cooling scheme for trapped atoms is proposed, which combines cavity-enhanced scattering and electromagnetically induced transparency. The cooling dynamics exploits a three-photon resonance, which combines laser and cavity excitations. It is shown that relatively fast ground-state cooling can be achieved in the Lamb-Dicke regime and for large cooperativity. Efficient ground-state cooling is found for parameters of ongoing experiments.

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

    OpenAIRE

    Silva Jr, Humberto Da; Raoult, Maurice; Aymar, Mireille; Dulieu, Olivier

    2015-01-01

    Radiative emission during cold collisions between trapped laser-cooled Rb atoms and alkaline-earth ions (Ca$^+$, Sr$^+$, Ba$^+$) and Yb$^+$, and between Li 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 radia...

  5. Detecting atoms trapped in an optical lattice using a tapered optical nanofiber

    CERN Document Server

    Hennessy, T

    2014-01-01

    Optical detection of structures with dimensions smaller than an optical wavelength requires devices that work on scales beyond the diffraction limit. Here we present the possibility of using a tapered optical nanofiber as a detector to resolve individual atoms trapped in an optical lattice in the Mott Insulator phase. We show that the small size of the fiber combined with an enhanced photon collection rate can allow for the attainment of large and reliable measurement signals.

  6. Production and trapping of radioactive atoms at the TRI\\muP facility

    OpenAIRE

    Traykov, E.; Dammalapati, U.; De, S.; Dermois, O. C.; Huisman, L.; Jungmann, K.; Kruithof, W.; Mol, A. J.; Onderwater, C.J.G.(Van Swinderen Institute, University of Groningen, Groningen, The Netherlands); Rogachevskiy, A.; Silva, M. da Silva e; Sohani, M.; Versolato, O.; Willmann, L.; Wilschut, H.W.

    2007-01-01

    The structures for the TRI$\\mu$P facility have been completed and commissioned. At the facility radioactive nuclides are produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atoms in order to obtain and hold a pure substrate-free sample for precision measurements. In the TRI$\\mu$P facility a production target is followed by a magnetic separator, where radioactive isotopes are produced in inverse reaction kinematics. Separation ...

  7. A=225 implantation for $^{221}$Fr source for TRIUMF atom trap

    CERN Multimedia

    The FrPNC Collaboration is mounting an atom trap for parity violation experiments and precision spectroscopy on francium atoms at TRIUMF's ISAC facility. We would like to use ISOLDE's capability of simultaneously implanting A=225 (while another experiment runs online) to make a long-lived source feeding $^{221}$Fr for tests of the trap. $^{225}$Ra $\\beta$-decays to $^{225}$Ac, which then $\\alpha$-decays, producing 100 keV $^{221}$Fr t$_{1/2}$= 4.8 minute recoils. The implanted A=225 source would be shipped to TRIUMF, where it would be held for several minutes at a time a few mm from the same yttrium foil that normally receives the ISAC beam. SRIM calculations imply that 20% of the $^{221}$Fr will be implanted in a 1 cm diameter spot on the yttrium. Then the yttrium foil is moved to the trap and heated to release the Fr atoms, just as in normal ISAC online operation. A test implantation will be done at 10$^{7}$/sec production for 1 day, testing whether carbon cracking on the implantation foil in the mass separ...

  8. Towards hybrid quantum systems: Trapping a single atom near a nanoscale solid-state structure

    Directory of Open Access Journals (Sweden)

    Tiecke T.G.

    2013-08-01

    Full Text Available We describe and demonstrate a method to deterministically trap single atoms near nanoscale solid-state objects. The trap is formed by the interference of an optical tweezer and its reflection from the nano object, creating a one-dimensional optical lattice where the first lattice site is at z0 ∼ λ/4 from the surface. Using a tapered optical fiber as the nanoscopic object, we characterize the loading into different lattice sites by means of the AC-Stark shift induced by a guided fiber mode. We demonstrate a loading efficiency of 94(6% into the first lattice site, and measure the cooperativity for the emission of the atom into the guided mode of the nanofiber. We show that by tailoring the dimensions of the nanofiber the distance of the trap to the surface can be adjusted. This method is applicable to a large variety of nanostructures and represents a promising starting point for interfacing single atoms with arbitrary nanoscale solid-state systems.

  9. Optical resonator for a standing wave dipole trap for fermionic lithium atoms

    International Nuclear Information System (INIS)

    This thesis reports on the the construction of an optical resonator for a new resonator dipole trap to store the fermionic 6Li-isotope and to investigate its scattering properties. It was demonstrated that the resonator enhances the energy density of a (1064 nm and 40 mW) laser beam by a factor of more than 100. A fused silica vacuum cell is positioned inside the resonator under Brewster's angle. The losses of the resonator depend mainly on the optical quality of the cell. The expected trap depth of the dipole trap is 200 μK and the photon scattering rate is expected to be about 0.4 s-1. The resonator is stabilized by means of a polarization spectroscopy method. Due to high trap frequencies, which are produced by the tight enclosure of the standing wave in the resonator, the axial motion must be quantized. A simple model to describe this quantization has been developed. A magneto-optical trap, which serves as a source of cold lithium atoms, was put in operation. (orig.)

  10. Measurement of Absolute Atomic Collision Cross Section with Helium Using 87Rb Atoms Confined in Magneto-Optic and Magnetic Traps

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-Cheng; ZHOU Ke-Ya; WANG Yue-Yuan; LIAO Qing-Hong; LIU Shu-Tian

    2011-01-01

    We present the measurements and calculations of the absolute total collision cross sections for a room-temperature gas of helium using 87 Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap. The loss rates from the magneto-optic trap and the pure magnetic trap are compared and show significant differences. The collision cross sections as a function of trap depth for helium gas are obtained. These findings are significant for extracting the information about the different cross sections when the trap depth is changed.%@@ We present the measurements and calculations of the absolute total collision cross sections for a room-temperature gas of helium using 87Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap.The loss rates from the magneto-optic trap and the pure magnetic trap are compared and show significant differences.The collision cross sections as a function of trap depth for helium gas are obtained.These findings are significant for extracting the information about the different cross sections when the trap depth is changed.

  11. Large Bragg Reflection from One-Dimensional Chains of Trapped Atoms Near a Nanoscale Waveguide

    Science.gov (United States)

    Corzo, Neil V.; Gouraud, Baptiste; Chandra, Aveek; Goban, Akihisa; Sheremet, Alexandra S.; Kupriyanov, Dmitriy V.; Laurat, Julien

    2016-09-01

    We report experimental observations of a large Bragg reflection from arrays of cold atoms trapped near a one-dimensional nanoscale waveguide. By using an optical lattice in the evanescent field surrounding a nanofiber with a period nearly commensurate with the resonant wavelength, we observe a reflectance of up to 75% for the guided mode. Each atom behaves as a partially reflecting mirror and an ordered chain of about 2000 atoms is sufficient to realize an efficient Bragg mirror. Measurements of the reflection spectra as a function of the lattice period and the probe polarization are reported. The latter shows the effect of the chiral character of nanoscale waveguides on this reflection. The ability to control photon transport in 1D waveguides coupled to spin systems would enable novel quantum network capabilities and the study of many-body effects emerging from long-range interactions.

  12. Atom trapping and guiding with a subwavelength-diameter optical fiber

    CERN Document Server

    Balykin, V I; Le Kien, F; Liang, J Q; Morinaga, M; Kien, Fam Le

    2004-01-01

    We suggest using an evanescent wave around a thin fiber to trap atoms. We show that the gradient force of a red-detuned evanescent-wave field in the fundamental mode of a silica fiber can balance the centrifugal force when the fiber diameter is about two times smaller than the wavelength of the light and the component of the angular momentum of the atoms along the fiber axis is in an appropriate range. As an example, the system should be realizable for Cesium atoms at a temperature of less than 0.29 mK using a silica fiber with a radius of 0.2 $\\mu$m and a 1.3-$\\mu$m-wavelength light with a power of about 27 mW.

  13. Precision spectroscopy of Mg atoms in a magneto-optical trap

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, A N; Brazhnikov, D V; Shilov, A M; Bagayev, S N [Novosibirsk State University, Novosibirsk (Russian Federation); Bonert, A E [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2014-06-30

    We report the results of experimental investigations aimed at creation of the optical frequency standard based on magnesium atoms cooled and localised in a magneto-optical trap (MOT). An experimentally realised MOT for magnesium made it possible to obtain a cloud comprising ∼10{sup 6} – 10{sup 7} atoms at a temperature of 3 – 5 mK. The results of ultra-high resolution spectroscopy of intercombination {sup 1}S{sub 0} – {sup 3}P{sub 1} transition for Mg atom are presented, the resonances in time-domain separated optical fields with the half-width of Γ = 500 Hz are recorded, which corresponds to the Q-factor of the reference line Q = ν/Δν ∼ 1.3 × 10{sup 12}. (extreme light fields and their applications)

  14. Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in 85Rb

    Institute of Scientific and Technical Information of China (English)

    LIU Lu; GUO Tao; DENG Ke; LIU Xin-Yuan; CHEN Xu-Zong; WANG Zhong

    2007-01-01

    An atomic clock system based on coherent population trapping (CPT) resonance in 85Rb is reported, while most past works about the CPT clock are in 87Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in 85Rb. The experimental results show that the short-term frequency stability of the CPT clock in 85Rb is in the order of 10-10/s and the long-term frequency stability can achieve 1.5 × 10-11 /80000s, which performs as well as 87Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of 85Rb indicates that an atomic clock based on CPT in 85 Rb should be a promising candidate for making the chip scale atomic clock.

  15. Large Bragg Reflection from One-Dimensional Chains of Trapped Atoms Near a Nanoscale Waveguide

    CERN Document Server

    Corzo, N V; Chandra, A; Goban, A; Sheremet, A S; Kupriyanov, D V; Laurat, J

    2016-01-01

    We report experimental observations of large Bragg reflection from arrays of cold atoms trapped near a one-dimensional nanoscale waveguide. By using an optical lattice in the evanescent field surrounding a nanofiber with a period close to commensurate with the resonant wavelength, we observe a reflectance up to 75% for the guided mode. Each atom behaves as a partially-reflecting mirror and an ordered chain of about 2000 atoms is sufficient to realize an efficient Bragg mirror. Measurements of the reflection spectra as a function of the lattice period and the probe polarization are reported. The latter shows the effect of the chiral character of nanoscale waveguides on this reflection. The ability to control photon transport in 1D waveguides coupled to spin systems would allow for novel quantum network capabilities and many-body effects emerging from long-range interactions.

  16. The determination, by atomic-absorption spectrophotometry, of trace elements in sulphide concentrates

    International Nuclear Information System (INIS)

    The separation, concentration, and determination of trace elements in base-metal and sulphide concentrates are described. After the sample has been dissolved, the trace elements that form insoluble hydroxides are precipitated with lanthanum as the coprecipitant and are separated from those elements that form soluble amines with ammonia. The precipitate is dissolved, and the trace elements selenium, tellurium, arsenic, antimony, bismuth, tin, vanadium, chromium, manganese, and aluminium are determined by atomic-absorption spectrophotometry. Coefficients of variation between 1 and 10 per cent, depending on the amount of the element, were obtained, with limits of determination ranging from 0,1 to 50 p.p.m

  17. Deformation-induced trace element redistribution in zircon revealed using atom probe tomography

    Science.gov (United States)

    Piazolo, Sandra; La Fontaine, Alexandre; Trimby, Patrick; Harley, Simon; Yang, Limei; Armstrong, Richard; Cairney, Julie M.

    2016-02-01

    Trace elements diffuse negligible distances through the pristine crystal lattice in minerals: this is a fundamental assumption when using them to decipher geological processes. For example, the reliable use of the mineral zircon (ZrSiO4) as a U-Th-Pb geochronometer and trace element monitor requires minimal radiogenic isotope and trace element mobility. Here, using atom probe tomography, we document the effects of crystal-plastic deformation on atomic-scale elemental distributions in zircon revealing sub-micrometre-scale mechanisms of trace element mobility. Dislocations that move through the lattice accumulate U and other trace elements. Pipe diffusion along dislocation arrays connected to a chemical or structural sink results in continuous removal of selected elements (for example, Pb), even after deformation has ceased. However, in disconnected dislocations, trace elements remain locked. Our findings have important implications for the use of zircon as a geochronometer, and highlight the importance of deformation on trace element redistribution in minerals and engineering materials.

  18. In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies

    Energy Technology Data Exchange (ETDEWEB)

    Kılınç, Ersin, E-mail: kilincersin@gmail.com [Medical Laboratory Techniques, Vocational Higher School of Healthcare Studies, Mardin Artuklu University, 47200 Mardin (Turkey); Bakırdere, Sezgin [Yıldız Technical University, Art and Science Faculy, Department of Chemistry, Esenler, TR 34220 İstanbul (Turkey); Aydın, Fırat [Dicle University, Faculty of Science, Department of Chemistry, Laboratory of Chemical Analysis, TR 21280 Diyarbakır (Turkey); Ataman, O. Yavuz [Middle East Technical University, Faculty of Arts and Sciences, Department of Chemistry, 06800 Ankara (Turkey)

    2013-11-01

    Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FAAS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 μg mL{sup −1} and 0.51 ng mL{sup −1}, respectively. Linear calibration plot was obtained in the range of 2.5–25.0 ng mL{sup −1} for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e. - Highlights: • Further increasing in sensitivity of SQT-AT-FAAS was obtained by using a W coated SQT. • 613 fold sensitivity enhancement was achieved by W coated SQT-AT-FAAS versus FAAS. • A sensitive, rapid and simple technique for Bi was developed with an LOD of 0.51 ng mL{sup −1}. • The technique is suggested for laboratories equipped with only a flame AA spectrometer.

  19. Magneto optical trap recoil ion momentum spectroscopy: application to ion-atom collisions

    International Nuclear Information System (INIS)

    87Rb atoms have been cooled, trapped and prepared as targets for collision studies with 2 and 5 keV Na+ projectiles. The physics studied deals with charge exchange processes. The active electron, which is generally the most peripheral electron of the atomic target, is transferred from the target onto the ionic projectile. The ionized target is called recoil ion. The technique used to study this physics is the MOTRIMS (Magneto Optical Trap Recoil Ion Momentum Spectroscopy) technique, which combines a magneto optical trap and a recoil ion momentum spectrometer. The spectrometer is used for the measurement of the recoil ions momentum, which gives access to all the information of the collision: the Q-value (which is the potential energy difference of the active electron on each particle) and the scattering angle of the projectile. The trap provides extremely cold targets to optimize the measurement of the momentum, and to release the latter from thermal motion. Through cinematically complete experiments, the MOTRIMS technique gives access to better resolutions on momentum measurements. Measurements of differential cross sections in initial and final capture states and in scattering angle have been done. Results obtained for differential cross sections in initial and final states show globally a good agreement with theory and an other experiment. Nevertheless, discrepancies with theory and this other experiment are shown for the measurements of doubly differential cross sections. These discrepancies are not understood yet. The particularity of the experimental setup designed and tested in this work, namely a low background noise, allows a great sensitivity to weak capture channels, and brings a technical and scientific gain compared with previous works. (author)

  20. Spin Diffusion in Trapped Clouds of Cold Atoms with Resonant Interactions

    DEFF Research Database (Denmark)

    Bruun, Georg Morten; Pethick, C. J.

    2011-01-01

    We show that puzzling recent experimental results on spin diffusion in a strongly interacting atomic gas may be understood in terms of the predicted spin diffusion coefficient for a generic strongly interacting system. Three important features play a central role: (a) Fick’s law for diffusion mus...... be modified to allow for the trapping potential; (b) the diffusion coefficient is inhomogeneous, due to the density variations in the cloud; and (c) the diffusion approximation fails in the outer parts of the cloud, where the mean free path is long....

  1. Progress towards precision measurements of beta-decay correlation parameters using atom and ion traps

    CERN Document Server

    Melconian, D; Fenker, B; Mehlman, M; Shidling, P D; Anholm, M; Ashery, D; Behr, J A; Gorelov, A; Gwinner, G; Olchankski, K; Smale, S

    2014-01-01

    The correlations of the decay products following the beta decay of nuclei have a long history of providing a low-energy probe of the fundamental symmetries of our universe. Over half a century ago, the correlation of the electrons following the decay of polarized 60Co demonstrated that parity is not conserved in weak interactions. Today, the same basic idea continues to be applied to search for physics beyond the standard model: make precision measurements of correlation parameters and look for deviations compared to their standard model predictions. Efforts to measure these parameters to the 0.1% level utilizing atom and ion trapping techniques are described.

  2. Quantum Degenerate Fermi-Bose Mixtures of 40K and 87Rb Atoms in a Quadrupole-Ioffe Configuration Trap

    Institute of Scientific and Technical Information of China (English)

    XIONG De-Zhi; CHEN Hai-Xia; WANG Peng-Jun; YU Xu-Dong; GAO Feng; ZHANG Jing

    2008-01-01

    @@ We report on the attainment of quantum degeneracy of 40K by means of efficient thermal collisions with the evaporatively cooled 87Rb atoms.In a quadrupole-Ioffe configuration trap,potassium atoms are cooled to 0.5 times the Fermi temperature.We obtain up to 7.59 × 105 degenerate fermions 40K.

  3. Sub-Doppler Laser Cooling of Thulium Atoms in a Magneto-optical Trap

    CERN Document Server

    Sukachev, D; Chebakov, K; Akimov, A; Kanorsky, S; Kolachevsky, N; Sorokin, V

    2010-01-01

    We have experimentally studied sub-Doppler laser cooling in a magneto-optical trap for thulium atoms working at the wavelength of 410.6\\,nm. Without any dedicated molasses period of sub-Doppler cooling, the cloud of $3\\times 10^6$ atoms at the temperature of 25(5)\\,$\\mu$K was observed. The measured temperature is significantly lower than the Doppler limit of 240$\\mu$K for the cooling transition at 410.6\\,nm. High efficiency of the sub-Doppler cooling process is due to a near-degeneracy of the Land\\'e-$g$ factors of the lower $4f^{13}6s^{2}\\, (J\\,=\\,{7}/{2})$ and the upper $4f^{12}5d_{3/2}6s^{2}\\, (J\\,=\\,{9}/{2})$ cooling levels.}

  4. Sub-Doppler Cooling of Neutral Atoms in a Grating Magneto-Optical Trap

    CERN Document Server

    Lee, J; Orozco, L A; Rolston, S L

    2013-01-01

    The grating magneto-optical trap (GMOT) requires only one beam and three planar diffraction gratings to form a cloud of cold atoms above the plane of the diffractors. Despite the complicated polarization arrangement, we demonstrate sub-Doppler cooling of 87Rb atoms to a temperature of 7.6(0.6) uK through a multi-stage, far-detuned GMOT in conjunction with optical molasses. A decomposition of the electric ?field into polarization components for this geometry does not yield a mapping onto standard sub-Doppler laser-cooling configurations. With numerical simulations, we find that the polarization composition of the GMOT optical field, which includes sigma?- and pi?-polarized light, does produce sub-Doppler temperatures.

  5. Direct Observation of Coherent Population Trapping in a Superconducting Artificial Atom

    CERN Document Server

    Kelly, William R; Ohki, Thomas A; Schlafer, John; Mookerji, Bashkar; Kline, Jeffrey S; Pappas, David P

    2009-01-01

    The phenomenon of Coherent Population Trapping (CPT) of an atom (or solid state "artificial atom"), and the associated effect of Electromagnetically Induced Transparency (EIT), are clear demonstrations of quantum interference due to coherence in multi-level quantum systems. We report observation of CPT in a superconducting phase qubit by simultaneously driving two coherent transitions in a $\\Lambda$-type configuration, utilizing the three lowest lying levels of a local minimum of a phase qubit. We observe 58% suppression of excited state population under conditions of CPT resonance. We present data and matching theoretical simulations showing the development of CPT in time. Finally, we used the observed time dependence of the excited state population to characterize quantum dephasing times of the system.

  6. Direct trace analysis of metals and alloys in a quadrupole ion-trap mass spectrometer

    CERN Document Server

    Song, K S; Yang, M; Cha, H K; Lee, J M; Lee, G H

    1999-01-01

    An ion-trap mass spectrometer adopting a quadrupole ion-trap and laser ablation/ionization method was constructed. The developed system was tested for composition analysis of some metals (Cu, stainless), and alloys (hastalloy C, mumetal) by mass spectrometry. Samples were analyzed by using laser ablation from a sample probe tip followed by a mass analysis with the quadrupole ion-trap. The quadrupole ion-trap was modified to enable laser ablation by a XeCl excimer laser pulse that passed radially through the ring electrode. A mass scan of the produced ions was performed in the mass selective instability mode wherein trapped ions were successively detected by increasing the rf voltage through the ring electrode. Factors affecting the mass resolution, such as pressure of buffer gas and ablation laser power, are discussed.

  7. Production and trapping of radioactive atoms at the TRI\\muP facility

    CERN Document Server

    Traykov, E; De, S; Dermois, O C; Huisman, L; Jungmann, K; Kruithof, W; Mol, A J; Onderwater, C J G; Rogachevskiy, A; Silva, M da Silva e; Sohani, M; Versolato, O; Willmann, L; Wilschut, H W

    2007-01-01

    The structures for the TRI$\\mu$P facility have been completed and commissioned. At the facility radioactive nuclides will be produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atom in order to obtain and hold a pure substrate-free sample that will allow precision measurements. The TRI$\\mu$P facility consists of a chain of several separate units: A production target followed by a magnetic separator produces fast radioactive isotopes. The separator is commissioned and is operating. Various modes to produce radioactive particles have been tested for optimal production. A thermal ionizer stops the fast products and transports the nuclides as low energy singly charged ions into a radio frequency quadrupole cooler and buncher. This allows one to collect and transport the ions via a drift tube and a low energy beam line into a magneto-optical trap (MOT). The ions are neutralized in the MOT chamber and will be transported to a second trap for $\\beta$...

  8. Production and trapping of radioactive atoms at the TRI{mu}P facility

    Energy Technology Data Exchange (ETDEWEB)

    Traykov, E. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands)], E-mail: traykov@kvi.nl; Dammalapati, U.; De, S.; Dermois, O.C.; Huisman, L.; Jungmann, K.; Kruithof, W.; Mol, A.J.; Onderwater, C.J.G.; Rogachevskiy, A.; Silva e Silva, M. da; Sohani, M.; Versolato, O.; Willmann, L.; Wilschut, H.W. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands)

    2008-10-15

    The structures for the TRI{mu}P facility have been completed and commissioned. At the facility radioactive nuclides are produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atoms in order to obtain and hold a pure substrate-free sample for precision measurements. In the TRI{mu}P facility a production target is followed by a magnetic separator, where radioactive isotopes are produced in inverse reaction kinematics. Separation up to 99.95% could be achieved for {sup 21}Na. A novel transmitting thermal ionizing device was developed to stop the energetic isotopes. Some 50% of stopped {sup 21}Na could be extracted and transported as low energy singly charged ions into a radio frequency quadrupole cooler and buncher with 35% transmission efficiency. The ions are transported lossless via a drift tube and a low energy electrostatic beam line into the experimental setup. Such ions can be neutralized on hot metal foils and the resulting atoms can be stored in a magneto-optical trap. The functioning of that principle was demonstrated with stable Na extracted from the thermal ionizer, radioactive beams will follow next.

  9. Production and trapping of radioactive atoms at the TRIμP facility

    Science.gov (United States)

    Traykov, E.; Dammalapati, U.; De, S.; Dermois, O. C.; Huisman, L.; Jungmann, K.; Kruithof, W.; Mol, A. J.; Onderwater, C. J. G.; Rogachevskiy, A.; da Silva e Silva, M.; Sohani, M.; Versolato, O.; Willmann, L.; Wilschut, H. W.

    2008-10-01

    The structures for the TRIμP facility have been completed and commissioned. At the facility radioactive nuclides are produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atoms in order to obtain and hold a pure substrate-free sample for precision measurements. In the TRIμP facility a production target is followed by a magnetic separator, where radioactive isotopes are produced in inverse reaction kinematics. Separation up to 99.95% could be achieved for 21Na. A novel transmitting thermal ionizing device was developed to stop the energetic isotopes. Some 50% of stopped 21Na could be extracted and transported as low energy singly charged ions into a radio frequency quadrupole cooler and buncher with 35% transmission efficiency. The ions are transported lossless via a drift tube and a low energy electrostatic beam line into the experimental setup. Such ions can be neutralized on hot metal foils and the resulting atoms can be stored in a magneto-optical trap. The functioning of that principle was demonstrated with stable Na extracted from the thermal ionizer, radioactive beams will follow next.

  10. Electrothermal atomization atomic absorption spectrometric determination of trace metals in uranium-plutomium fuel materials

    International Nuclear Information System (INIS)

    Atomic absorption spectrometric methods using the electrothermal mode of atomization developed for the determination of Ag, Be, Ca, Cd, Cr, Co, Cu, Fe, Li, Mn, Na, Ni, Sn and Zn in (U, Pu) solution with 4% plutonium have been described. The carbon rod atomizer has been adapted for glove box operation to enable handling of plutonium containing solution samples. Multielement solution standards with graded concentrations of the analytes and fixed concentration of the matrix are used in the standardization process. Nanogram to sub-nanogram quantities of the analytes have been determined with a precision of better than 9% RSD using 5 μl of the sample aliquots. (orig.)

  11. Optical cooling and trapping highly magnetic atoms: The benefits of a spontaneous spin polarization

    CERN Document Server

    Dreon, Davide; Bouazza, Chayma; Maineult, Wilfried; Dalibard, Jean; Nascimbene, Sylvain

    2016-01-01

    From the study of long-range-interacting systems to the simulation of gauge fields, open-shell Lanthanide atoms with their large magnetic moment and narrow optical transitions open novel directions in the field of ultracold quantum gases. As for other atomic species, the magneto-optical trap (MOT) is the working horse of experiments but its operation is challenging, due to the large electronic spin of the atoms. Here we present an experimental study of narrow-line Dysprosium MOTs. We show that the combination of radiation pressure and gravitational forces leads to a spontaneous polarization of the electronic spin. The spin composition is measured using a Stern-Gerlach separation of spin levels, revealing that the gas becomes almost fully spin-polarized for large laser frequency detunings. In this regime, we reach the optimal operation of the MOT, with samples of typically $3\\times 10^8$ atoms at a temperature of 20$\\,\\mu$K. The spin polarization reduces the complexity of the radiative cooling description, whi...

  12. Lead determination at ng/mL level by flame atomic absorption spectrometry using a tantalum coated slotted quartz tube atom trap.

    Science.gov (United States)

    Demirtaş, İlknur; Bakırdere, Sezgin; Ataman, O Yavuz

    2015-06-01

    Flame atomic absorption spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years, atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of µg/mL, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of the atom traps used to improve sensitivity. In atom trapping mode of SQT, analyte is trapped on-line in SQT for few minutes using ordinary sample aspiration, followed by the introduction of a small volume of organic solvent to effect the revolatilization and atomization of analyte species resulting in a transient signal. This system is economical, commercially available and easy to use. In this study, a sensitive analytical method was developed for the determination of lead with the help of SQT atom trapping flame atomization (SQT-AT-FAAS). 574 Fold sensitivity enhancement was obtained at a sample suction rate of 3.9 mL/min for 5.0 min trapping period with respect to FAAS. Organic solvent was selected as 40 µL of methyl isobutyl ketone (MIBK). To obtain a further sensitivity enhancement inner surface of SQT was coated with several transition metals. The best sensitivity enhancement, 1650 fold enhancement, was obtained by the Ta-coated SQT-AT-FAAS. In addition, chemical nature of Pb species trapped on quartz and Ta surface, and the chemical nature of Ta on quartz surface were investigated by X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. Raman spectrometric results indicate that tantalum is coated on SQT surface in the form of Ta2O5. XPS studies revealed that the oxidation state of Pb in species trapped on both bare and Ta coated SQT surfaces is +2. For the accuracy check, the analyses of standard reference material were performed by use of SCP SCIENCE EnviroMAT Low (EU-L-2) and results for Pb were to be in good agreement with

  13. Determination of trace elements in ground water by two preconcentration methods using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This is a comparative study between two different methods of preconcentration done to separate the trace elements cadmium, nickel. chromium, manganese, copper, zinc, and lead in drinking (ground) water samples taken from different locations in Gezira State, central Sudan (the map); these methods are (coprecipitation) with aluminium hydroxide and by Ammonium Pyrrolidine Dithiocarbamate (APDC) using Methyl Isobutyl Ketone (MIBK) as an organic solvent; and subsequent analysis by Atomic Absorption Spectrometry (AAS) for both methods. The result of comparison showed the superiority of the (APDC) coprecipitation method over the aluminium hydroxide coprecipitation method in the total percentage recoveries of the studied trace elements in drinking (ground) water samples, such results confirm previous studies. This study also involves direct analysis of these water samples by atomic absorption spectrometry to determine the concentrations of trace elements Cadmium, Nickel, Chromium, Manganese, Copper, Zinc and Lead and compare it to the corresponding guide line values described by the World Health Organization and the maximum concentrations of trace elements in drinking water permitted by the Sudanese Standards and Metrology Organizations (SSMO), where the concentrations of some elements in some samples were found to be different than the described values by both of the organizations. The study includes a trial to throw light on the effect of the proximity of the water samples sources to the Blue Nile river on its trace elements concentrations; no relation was proved to exist in that respect.(Author)

  14. Radiative and collisional processes in translationally cold samples of hydrogen Rydberg atoms studied in an electrostatic trap

    Science.gov (United States)

    Seiler, Ch; Agner, J. A.; Pillet, P.; Merkt, F.

    2016-05-01

    Supersonic beams of hydrogen atoms, prepared selectively in Rydberg–Stark states of principal quantum number n in the range between 25 and 35, have been deflected by {90}\\circ , decelerated and loaded into off-axis electric traps at initial densities of ≈ {10}6 atoms cm‑3 and translational temperatures of 150 mK. The ability to confine the atoms spatially was exploited to study their decay by radiative and collisional processes. The evolution of the population of trapped atoms was measured for several milliseconds in dependence of the principal quantum number of the initially prepared states, the initial Rydberg-atom density in the trap, and the temperature of the environment of the trap, which could be varied between 7.5 and 300 K using a cryorefrigerator. At room temperature, the population of trapped Rydberg atoms was found to decay faster than expected on the basis of their natural lifetimes, primarily because of absorption and emission stimulated by the thermal radiation field. At the lowest temperatures investigated experimentally, the decay was found to be multiexponential, with an initial rate scaling as {n}-4 and corresponding closely to the natural lifetimes of the initially prepared Rydberg–Stark states. The decay rate was found to continually decrease over time and to reach an almost n-independent rate of more than (1 ms)‑1 after 3 ms. To analyze the experimentally observed decay of the populations of trapped atoms, numerical simulations were performed which included all radiative processes, i.e., spontaneous emission as well as absorption and emission stimulated by the thermal radiation. These simulations, however, systematically underestimated the population of trapped atoms observed after several milliseconds by almost two orders of magnitude, although they reliably predicted the decay rates of the remaining atoms in the trap. The calculations revealed that the atoms that remain in the trap for the longest times have larger absolute values

  15. The determination of trace metals in lubricating oils by atomic spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aucelio, Ricardo Q. [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil)], E-mail: aucelior@rdc.puc-rio.br; Martins de Souza, Roseli; Calixto de Campos, Reinaldo; Miekeley, Norbert; Porto da Silveira, Carmem L. [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil)

    2007-09-15

    The determination of trace metals in lubricating oils using atomic spectrometric methods is reviewed. The importance of such analyses for technical diagnostics as well as the specific sample characteristics related to the analyte form (metallo-organic and metal particles) is discussed. Problems related to sample pre-treatment for appropriate sample introduction and calibration are addressed as well as the strategies to overcome them. Recent trends aimed at simplifying sample manipulation are presented. The applications and scope of AAS, ICP OES and ICP MS techniques for the determination of trace metals in lubricating oil is individually discussed, as well as some present instrumental trends.

  16. Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals $C_6$ coefficients

    CERN Document Server

    Li, Hui; Dulieu, Olivier; Nascimbene, Sylvain; Lepers, Maxence

    2016-01-01

    The efficiency of optical trapping of ultracold atoms depend on the atomic dynamic dipole polarizability governing the atom-field interaction. In this article, we have calculated the real and imaginary parts of the dynamic dipole polarizability of dysprosium in the ground and first excited level. Due to the high electronic angular momentum of those two states, the polarizabilities possess scalar, vector and tensor contributions that we have computed, on a wide range of trapping wavelengths, using the sum-over-state formula. Using the same formalism, we have also calculated the $C_6$ coefficients characterizing the van der Waals interaction between two dysprosium atoms in the two lowest levels. We have computed the energies of excited states and the transition probabilities appearing in the sums, using a combination of \\textit{ab initio} and least-square-fitting techniques provided by the Cowan codes and extended in our group. Regarding the real part of the polarizability, for field frequencies far from atomic...

  17. One- and Two-Dimensional Arrays of Double-Well Optical Traps for Cold Atoms or Molecules

    Institute of Scientific and Technical Information of China (English)

    JI Xian-Ming; YIN Jian-Ping

    2004-01-01

    @@ We propose a novel scheme to form one- and two-dimensional arrays of double-well optical dipole traps for cold atoms (or molecules) by using an optical system composed of a binary π-phase grating and a lens illuminated by a plane light wave, and study the relationship between the maximum intensity Imax of each optical well (or the maximum trapping potential Umax for 85Rb atoms) and the relative apertureβ (= a/f) of the lens. We also calculate the intensity gradients of each optical well and their curvatures, and estimate the spontaneous photon-scattering rate of trapped atom in each well, including Rayleigh and Raman scattering rates. Our study shows that the proposed 1D and 2D arrays of double-well traps can be used to prepare 1D and 2D novel optical lattices with cold atoms (or molecules), or form an all-optically integrated atom optical chip, or even to realize an array of all-optical double-well atomic (or molecular) Bose-Einstein condensates by optical-potential evaporative cooling, and so on.

  18. Solder self-assembled, surface micromachined MEMS for micromirror applications and atom trapping

    Science.gov (United States)

    McCarthy, Brian

    Solder self-assembly can be used to expand the versatility of a commercial foundry, like MEMSCAP's PolyMUMPs process. These foundries are attractive for prototyping MEMS as they can offer consistent, low cost fabrication runs by sticking to a single process and integrating multiple customers on each wafer. However, this standardization limits the utility of the process for a given application. Solder self-assembly gives back some of this versatility and expands the envelope of surface micromachining capability in the form of a simple post-process step. Here it is used to create novel micromirrors and micromirror arrays as well as to delve into the field of ultracold atom optics where the utility of MEMS as an enabling technology for atom control is explored. Two types of torsional, electrostatic micromirrors are demonstrated, both of which can achieve +/-10° of rotation. The first is a novel out-of-plane micromirror that can be rotated to a desired angle from the substrate. This integrated, on-chip assembly allows much simpler packaging technology to be used for devices that require a laser beam to be steered off-chip. Planar micromirror arrays that use solder self-assembly to tailor the electrode gap height are also demonstrated. With these designs, no special fabrication techniques are required to achieve large gap heights, and micromirrors with a variety of gap heights can even be fabricated on the same chip. Finally, solder self-assembly is used to explore how complex micro-scale structures can be used to control ultracold atoms. For this study, a MEMS version of a magneto-optical trap, the basis for most ultracold atomic systems, is used to control Rb atoms. In doing so, it provides a path for the successful integration of a number of MEMS devices in these types of systems.

  19. Nanofabrication for On-Chip Optical Levitation, Atom-Trapping, and Superconducting Quantum Circuits

    Science.gov (United States)

    Norte, Richard Alexander

    a final value of Qm = 5.8(1.1) x 105, representing more than an order of magnitude improvement over the conventional limits of SiO2 for a pendulum geometry. Our technique may enable new opportunities for mechanical sensing and facilitate observations of quantum behavior in this class of mechanical systems. We then give a detailed overview of the techniques used to produce high-aspect-ratio nanostructures with applications in a wide range of quantum optics experiments. The ability to fabricate such nanodevices with high precision opens the door to a vast array of experiments which integrate macroscopic optical setups with lithographically engineered nanodevices. Coupled with atom-trapping experiments in the Kimble Lab, we use these techniques to realize a new waveguide chip designed to address ultra-cold atoms along lithographically patterned nanobeams which have large atom-photon coupling and near 4pi Steradian optical access for cooling and trapping atoms. We describe a fully integrated and scalable design where cold atoms are spatially overlapped with the nanostring cavities in order to observe a resonant optical depth of d0 ≈ 0.15. The nanodevice illuminates new possibilities for integrating atoms into photonic circuits and engineering quantum states of atoms and light on a microscopic scale. We then describe our work with superconducting microwave resonators coupled to a phononic cavity towards the goal of building an integrated device for quantum-limited microwave-to-optical wavelength conversion. We give an overview of our characterizations of several types of substrates for fabricating a low-loss high-frequency electromechanical system. We describe our electromechanical system fabricated on a SiN membrane which consists of a 12 GHz superconducting LC resonator coupled capacitively to the high frequency localized modes of a phononic nanobeam. Using our suspended membrane geometry we isolate our system from substrates with significant loss tangents

  20. Coherent population trapping resonances at lower atomic levels of Doppler broadened optical lines

    Energy Technology Data Exchange (ETDEWEB)

    Şahin, E; Hamid, R; Çelik, M [National Metrology Institute of Turkey, Gebze, Kocaeli (Turkey); Özen, G [Istanbul Technical University, Faculty of Science and Letters, Engineering Physics Department Maslak, Istanbul (Turkey); Izmailov, A Ch [Institute of Physics, Azerbaijan National Academy of Sciences, H. Javid av. 33, Baku, Az-1143 (Azerbaijan)

    2014-11-30

    We have detected and analysed narrow high-contrast coherent population trapping (CPT) resonances, which are induced in absorption of a weak monochromatic probe light beam by counterpropagating two-frequency pump radiation in a cell with rarefied caesium vapour. The experimental investigations have been performed by the example of nonclosed three level Λ-systems formed by spectral components of the D{sub 2} line of caesium atoms. The applied method allows one to analyse features of the CPT phenomenon directly at a given low long-lived level of the selected Λ-system even in sufficiently complicated spectra of atomic gases with large Doppler broadening. We have established that CPT resonances in transmission of the probe beam exhibit not only a higher contrast but also a much lesser width in comparison with well- known CPT resonances in transmission of the corresponding two-frequency pump radiation. The results obtained can be used in selective photophysics, photochemistry and ultra-high resolution atomic (molecular) spectroscopy. (laser applications and other topics in quantum electronics)

  1. Atomic-absorption spectrometric determination of trace metals in zirconium and zircaloy by discrete sample nebulization

    International Nuclear Information System (INIS)

    A discrete sample nebulization technique was employed to determine trace metals in nuclear grade zirconium and Zircaloy by flame atomic-absorption spectrometry. With 10% (w/v) sample solutions, detection limits for Cd, Cu, Mn, Ni and Pb were 0.6, 2, 1, 3, and 10 μg/g. Micro standard-addition procedures and background correction were employed to minimize matrix interferences produced by the high salt content of the aspirated solutions. (author)

  2. Dispersive response of atoms trapped near the surface of an optical nanofiber with applications to QND measurement and spin squeezing

    CERN Document Server

    Qi, Xiaodong; Jessen, Poul S; Deutsch, Ivan H

    2015-01-01

    We study the strong coupling between photons and atoms that can be achieved in an optical nanofiber geometry when the interaction is dispersive. While the Purcell enhancement factor for spontaneous emission into the guided mode does not reach the strong-coupling regime for individual atoms, one can obtain high cooperativity for ensembles of a few thousand atoms due to the tight confinement of the guided modes and constructive interference over the entire chain of trapped atoms. We calculate the dyadic Green's function, which determines the scattering of light by atoms in the presence of the fiber, and thus the phase shift and polarization rotation induced on the guided light by the trapped atoms. The Green's function is related to a full Heisenberg-Langevin treatment of the dispersive response of the quantized field to tensor polarizable atoms. We apply our formalism to quantum nondemolition (QND) measurement of the atoms via polarimetry. We study shot-noise-limited detection of atom number for atoms in a com...

  3. First observation of the strongly forbidden transition 1S0 - 3P0 in Strontium, for an atomic clock with trapped atoms

    International Nuclear Information System (INIS)

    This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the 1S0-1P1 transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the 1S0-3P0 clock transition in 87Sr. This line has a theoretical natural width of 10-3 Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

  4. Scheme for generating the singlet state of three atoms trapped in distant cavities coupled by optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong-Yang [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wen, Jing-Ji [College of Foundation Science, Harbin University of Commerce, Harbin, Heilongjiang 150028 (China); Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wang, Hong-Fu, E-mail: hfwang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhu, Ai-Dong [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhang, Shou, E-mail: szhang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China)

    2015-09-15

    An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.

  5. Competition between Spin Echo and Spin Self-Rephasing in a Trapped Atom Interferometer

    CERN Document Server

    Solaro, Cyrille; Combes, Frédéric; Lopez, Matthias; Alauze, Xavier; Fuchs, Jean-Noël; Piéchon, Frédéric; Santos, Franck Pereira dos

    2016-01-01

    We perform Ramsey interferometry on an ultracold 87Rb ensemble confined in an optical dipole trap. We use a $\\pi$-pulse set at the middle of the interferometer to restore the coherence of the spin ensemble by canceling out phase inhomogeneities and creating a spin echo in the contrast. However, for high atomic densities, we observe the opposite behavior: the $\\pi$-pulse accelerates the dephasing of the spin ensemble leading to a faster contrast decay of the interferometer. We understand this phenomenon as a competition between the spin-echo technique and an exchange-interaction driven spin self-rephasing mechanism based on the identical spin rotation effect (ISRE). Our experimental data is well reproduced by a numerical model.

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

    Science.gov (United States)

    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).

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

    CERN Document Server

    Silva, Humberto Da; Aymar, Mireille; Dulieu, Olivier

    2015-01-01

    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 are also calculated, showing that the final molecular ions are not created in their ground state level.

  8. Shaping the evanescent field of optical nanofibers for cold atom trapping

    CERN Document Server

    Phelan, C F; Busch, Th

    2013-01-01

    We investigate trapping geometries for cold, neutral atoms that can be created in the evanescent field of a tapered optical fibre by combining the fundamental mode with one of the next lowest possible modes, namely the HE21 mode. Counter propagating red-detuned HE21 modes are combined with a blue-detuned HE11 fundamental mode to form a potential in the shape of four intertwined spirals. By changing the polar- ization from circular to linear in each of the two counter-propagating HE21 modes simultaneously the 4-helix configuration can be transformed into a lattice configuration. The modification to the 4-helix configuration due to unwanted excitation of the the T E01 and T M01 modes is also discussed.

  9. Spectral narrowing of coherent population trapping resonance in laser-cooled and room-temperature atomic gas

    Indian Academy of Sciences (India)

    S Pradhan; S Mishra; R Behera; N Kawade; A K Das

    2014-02-01

    We have investigated coherent population trapping (CPT) in laser-cooled as well as room-temperature (with and without buffer gas) rubidium atoms. The characteristic broad signal profile emerging from the two-photon Raman resonance for room-temperature atomic vapour is consistent with the theoretical calculation incorporating associated thermal averaging. The spectral width of the dark resonance obtained with cold atoms is found to be broadened, compared to roomtemperature vapour cell, due to the feeble role played by thermal averaging, although the cold atomic sample significantly overcomes the limitation of the transit time broadening. An alternative way to improve transit time is to use a buffer gas, with which we demonstrate that the coherent population trapping signal width is reduced to < 540 Hz.

  10. Coherent injecting, extracting, and velocity filtering of neutral atoms in a ring trap via spatial adiabatic passage

    CERN Document Server

    Loiko, Yurii; Menchon-Enrich, Ricard; Birkl, Gerhard; Mompart, Jordi

    2014-01-01

    We introduce here a coherent technique to inject, extract, and velocity filter neutral atoms in a ring trap coupled via tunneling to two additional waveguides. By adiabatically following the transverse spatial dark state, the proposed technique allows for an efficient and robust velocity dependent atomic population transfer between the ring and the input/output waveguides. We have derived explicit conditions for the spatial adiabatic passage that depend on the atomic velocity along the input waveguide as well as on the initial population distribution among the transverse vibrational states. The validity of our proposal has been checked by numerical integration of the corresponding two dimensional Schr\\"odinger equation with state-of-the-art parameter values for $^{87}$Rb atoms and an optical dipole ring trap.

  11. Electrochemical preconcentration and hydride generation methods for trace determination of selenium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The use of atomic absorption spectrometry in combination with two different preconcentration/separation techniques for the determination of trace concentrations of selenium is described. Electrochemical preconcentration onto a platinum electrode with a subsequent atomization of selenium is discussed briefly. Several parameters are considered such as the presence of depolarizers, and the temperature of the electrolyzed solutions. Special attention is payed to the efficiency of the atomization step, and a method to improve this is proposed. Applications of the technique to real samples are also reported. Secondly, the separation of the selenium as the volatile selenium hydride from the sample solution is considered. Several papers in this thesis deal with commonly occurring interferants as nickel and copper and with ways of minimizing or avoiding the interferring effects, whereas other papers relate to more theoretical aspects of the hydride generation process. New methods for the determination of selenium in technical samples with high contents of nickel and copper are also presented

  12. Green method for ultrasensitive determination of Hg in natural waters by electrothermal-atomic absorption spectrometry following sono-induced cold vapor generation and 'in-atomizer trapping'

    International Nuclear Information System (INIS)

    Sono-induced cold vapor generation (SI-CVG) has been used for the first time in combination with a graphite furnace atomizer for determination of Hg in natural waters by electrothermal-atomic absorption spectrometry after in situ trapping onto a noble metal-pretreated platform (Pd, Pt or Rh) inserted into a graphite tube. The system allows 'in-atomizer trapping' of Hg without the use of conventional reduction reactions based on sodium borohydride or tin chloride in acid medium for cold vapor generation. The sono-induced reaction is accomplished by applying ultrasound irradiation to the sample solution containing Hg(II) in the presence of an organic compound such as formic acid. As this organic acid is partly degraded upon ultrasound irradiation to yield CO, CO2, H2 and H2O, the amount of lab wastes is minimized and a green methodology is achieved. For this purpose, experimental variables influencing the generation/trapping process are fully investigated. The limit of detection for a 10 min trapping time and 10 mL sample volume was 0.03 μg L-1 (Integrated absorbance) and the repeatability expressed as relative standard deviation was about 3%. Carbonates and chlorides at 100 mg L-1 level caused a signal depression by 20-30%. The enhanced trapping efficiency observed with the sono-induced cold vapor generation as compared with 'in-atomizer trapping' methods employing chemical vapor generation is discussed. A reaction pathway for SI-CVG is proposed on the basis of the current knowledge for synthesis of noble metal nanoparticles by ultrasound

  13. Nobel Prize in Physics 1997 "for development of methods to cool and trap atoms with laser light" : Steven Chu, Claude Cohen-Tannoudji and William D. Phillips

    CERN Multimedia

    1998-01-01

    Prof.S. Chu presents "the manipulation of atoms and bio-molecules by laser light" : a brief history of the laser cooling and trapping of atoms developed over the past 15 years will be presented. The cooling and trapping technology is already being applied in numerous areas of science and engineering. Applications to be discussed include atomic clocks, atom interferometers, as well as studies in polymer dynamics and protein motion.

  14. The Trapping and Cooling of Alkalis Metal Atoms%碱金属原子的囚禁与冷却

    Institute of Scientific and Technical Information of China (English)

    邓海明; 李璋

    2012-01-01

      描述了如何利用激光以及磁场构建光学粘胶、激光阱、磁阱、磁光阱等实现对碱金属的囚禁与冷却,旨在明晰的呈现BEC实验实现的关键技术、物理原理以及各种装置的优缺点。%  This essay describes how to use laser and magnetic field to construct optical molasses ,laser trap ,mag-netic trap and magneto -optical trap to trap and cool alkali-metal atoms .It presents clearly the key experimental technologies of Bose-Einstein condensate ,the physical principle and the relative advantages and disadvantages of different equipments .

  15. Influence of matrix effects on determination of the trace element content in zirconium by the atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    A.N. Kulik

    2009-01-01

    Full Text Available The influence of sample matrix prepared on the basis of hydrofluoric acid on the measured content of trace elements in zirconium was studied. The accuracy of determination of the trace element content was verified by the “introduced-found” method. Based on verification results the temperature regime of electrothermal atomizer was optimized.

  16. Modified oscillator approach to ultracold collisions in tight harmonic traps General model and application to metastable helium atoms

    CERN Document Server

    Peach, G; Beams, T J; Peach, Gillian; Whittingham, Ian B; Beams, Timothy J

    2002-01-01

    A novel modified oscillator method of calculating energy eigenvalues for colliding ultracold atoms tightly confined in harmonic potentials is presented and applied to trapped spin-polarized metastable helium atoms. The perturbed harmonic oscillator problem is characterized by a long asymptotic region beyond the effective range of the interatomic potential, and a very efficient method for integrating inwards through this outer region is developed. The calculated eigenvalues for states with $l=0$ agree closely with those computed directly from the radial Schr\\"{o}dinger equation for the trapped atoms using a discrete variable method, and with those computed self-consistently from an energy-dependent effective scattering length. Finally, the self-consistent method is generalized to collisions with $l \

  17. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    Science.gov (United States)

    Borges, L. H. C.; Barone, F. A.

    2016-02-01

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schrödinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector.

  18. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    International Nuclear Information System (INIS)

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schroedinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector. (orig.)

  19. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    Energy Technology Data Exchange (ETDEWEB)

    Borges, L.H.C. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil); Barone, F.A. [IFQ-Universidade Federal de Itajuba, Itajuba, MG (Brazil)

    2016-02-15

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schroedinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector. (orig.)

  20. The dynamics of triple-well trapped Bose-Einstein condensates with atoms feeding and loss effects

    Institute of Scientific and Technical Information of China (English)

    Mu Ai-Xia; Zhou Xiao-Yan; Xue Ju-Kui

    2008-01-01

    In this paper, we consider the macroscopic quantum tunnelling and self-trapping phenomena of Bose-Einstein condensates (BECs) with three-body recombination losses and atoms feeding from thermal cloud in triple-well potential.Using the three-mode approximation, three coupled Gross-Pitaevskii equations (GPEs), which describe the dynamics of the system, are obtained. The corresponding numerical results reveal some interesting characteristics of BECs for different scattering lengths. The self-trapping and quantum tunnelling both are found in zero-phase and π-pbaso modes.Furthermore, we observe the quantum beating phenomenon and the resonance character during the self-trapping and quantum tunnelling. It is also shown that the initial phase has a significant effect on the dynamics of the system.

  1. The determination of traces of rare earths in other rare earths by atomic absorption with electrothermal atomization and by d.c. arc emission spectrography

    International Nuclear Information System (INIS)

    The determination of traces of some rare earth elements (Yb, Eu, Tm, Sm, Dy, Ho, Er) in matrices of other rare earths by a.a.s. with electrothermal atomization (tantalum ribbon), and of traces of Tm and Dy by a.e.s. with d.c. arc excitation is described. The influence of the boiling points of the traces and matrices on the possibility and the sensitivity of the a.a.s. determinations is discussed. The results of the methods are compared. Better absolute, and in most cases also relative, detection limits can be achieved by a.a.s

  2. Optical Guiding of Trapped Atoms by a Blue-Detuned Hollow Laser Beam in the Horizontal Direction

    Institute of Scientific and Technical Information of China (English)

    JIANG Kai-Jun; LI Ke; WANG Jin; ZHAN Ming-Sheng

    2005-01-01

    @@ Optical guiding of 85 Rb atoms in a magneto-optical trap (MOT) by a blue-detuned horizontal hollow laser beam is demonstrated experimentally. The guiding efficiency and the velocity distribution of the guided atoms are found to have strong dependence on the detuning of the guiding laser. In particular, the optimum guiding occurs when the blue detuning of the hollow laser beam is approximately equal to the hyperfine structure splitting of the 85Rb ground states, in good agreement with the theoretical analysis based on a three-level model.

  3. Generation of 99-mW continuous-wave 285-nm radiation for magneto-optical trapping of Mg atoms

    DEFF Research Database (Denmark)

    Madsen, Dorte Nørgaard; Yu, Ping; Balslev, Søren;

    2002-01-01

    We have developed a tunable intense narrow-band 285 nm light source based on frequency doubling of 570 nm light in BBO. At input powers of 840 mW (including 130 mW used for locking purposes) we generate 99 mW UV radiation with an intensity profile suitable for laser-cooling experiments. The light...... is used for laser cooling of neutral magnesium atoms in a magneto-optical trap (MOT). We capture about 5 x 10(6) atoms directly from a thermal beam and find that the major loss mechanism of the magnesium MOT is a near-resonant two-photon ionization process....

  4. Generation of 99-mW continuous-wave 285-nm radiation for magneto-optical trapping of Mg atoms

    DEFF Research Database (Denmark)

    Madsen, D. N; Yu, P.; Balslev, S.;

    2002-01-01

    We have developed a tunable intense narrow-band 285 nm light source based on frequency doubling of 570 nm light in BBO. At input powers of 840 mW (including 130 mW used for locking purposes) we generate 99 mW UV radiation with an intensity profile suitable for laser-cooling experiments. The light...... is used for laser cooling of neutral magnesium atoms in a magneto-optical trap (MOT). We capture about 5×106 atoms directly from a thermal beam and find that the major loss mechanism of the magnesium MOT is a near-resonant two-photon ionization process....

  5. Under-coordinated atoms induced local strain, quantum trap depression and valence charge polarization at W stepped surfaces

    International Nuclear Information System (INIS)

    We have explored the effects of atoms under-coordination on surface structure relaxation, binding energy shift of W stepped surfaces and valence charge polarization by the method of incorporating bond order-length-strength (BOLS) correlation mechanism into high-resolution X-ray photoluminescence spectra (XPS) measurements as well as density functional theory (DFT) calculations. Results show that the 4f7/2 energy levels of bulk, surface skin and step edge W atoms shift deeper from 2.17 to 2.69 eV with respect to that of the isolated W (28.91±0.01 eV) atoms, while the valence charge energy shift upper from inner to outer layer and from bulk to stepped edge. The surface bond contraction occurs around under-coordinated atoms after geometry relaxation calculation. Consistency among BOLS calculations, DFT calculation and experimental measurements clarifies that the surface bond contraction and consolidation due to the effects of under-coordination atoms induce potential trap depression, which provides perturbation to the Hamiltonian and hence contributes to the surface core level shift deeper, and that the surface valence charge are polarized by the densely trapped core-level electrons to upper energy.

  6. Chaotic atomic population oscillations between two coupled Bose-Einstein condensates with time-dependent asymmetric trap potential

    OpenAIRE

    Lee, Chaohong; Shi, Lei; Zhu, Xiwen; Gao, Kelin; Hai, Wenhua; Duan, Yiwu; Liu, Wing-Ki

    2000-01-01

    We have investigated the chaotic atomic population oscillations between two coupled Bose-Einstein condensates (BEC) with time-dependent asymmetric trap potential. In the perturbative regime, the population oscillations can be described by the Duffing equation, and the chaotic oscillations near the separatrix solution are analyzed. The sufficient-necessary conditions for stable oscillations depend on the physical parameters and initial conditions sensitively. The first-order necessary conditio...

  7. Quantum Wigner molecules in semiconductor quantum dots and cold-atom optical traps and their mathematical symmetries

    CERN Document Server

    Yannouleas, Constantine

    2016-01-01

    Strong repelling interactions between a few fermions or bosons confined in two-dimensional circular traps lead to particle localization and formation of quantum Wigner molecules (QWMs) possessing definite point-group space symmetries. These point-group symmetries are "hidden" (or emergent), namely they cannot be traced in the circular single-particle densities (SPDs) associated with the exact many-body wave functions, but they are manifested as characteristic signatures in the ro-vibrational spectra. An example, among many, are the few-body QWM states under a high magnetic field or at fast rotation, which are precursor states for the fractional quantum Hall effect. The hidden geometric symmetries can be directly revealed by using spin-resolved conditional probability distributions, which are extracted from configuration-interaction (CI), exact-diagonalization wave functions. The hidden symmetries can also be revealed in the CI SPDs by reducing the symmetry of the trap (from circular to elliptic to quasi-linea...

  8. Suppression of single cesium atom heating in a microscopic optical dipole trap for demonstration of an 852nm triggered single-photon source

    CERN Document Server

    Liu, Bei; He, Jun; Wang, Junmin

    2016-01-01

    We investigate single cesium (Cs) atom heating owing to the momentum accumulation process induced by the resonant pulsed excitation in a microscopic optical dipole trap formed by a strongly focused 1064 nm laser beam. The heating depends on the trap frequency which restricts the maximum repetition rate of pulsed excitation. We experimentally verify the heating of a single atom and then demonstrate how to suppress it with an optimized pulsed excitation/cooling method. The typical trap lifetime of single Cs atom is extended from 108 +/- 6 us to 2536 +/- 31 ms, and the corresponding number of excitation increases from ~ 108 to ~ 360000. In applying this faster cooling method, we use the trapped single Cs atom as a triggered single-photon source at an excitation repetition rate of 10 MHz. The second-order intensity correlations of the emitted single photons are characterized by implementing Hanbury Brown and Twiss setup, and clear anti-bunching effect has been observed.

  9. Quantum phase gate through the dispersive atom–field interaction with atoms trapped in optical cavity QED

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Dong; Zhang, Yan-Lei; Zou, Chang-Ling, E-mail: clzou321@ustc.edu.cn; Zou, Xu-Bo, E-mail: xbz@ustc.edu.cn; Guo, Guang-Can

    2015-10-09

    We propose an experimental feasible scheme for implementing two-qubit quantum phase gate with atoms trapped in an optical cavity. The scheme is based on the dispersive interaction between the optical cavity mode and the three-level atoms in Λ configuration, which has been demonstrated in recent cavity-induced spin squeezing experiment (Leroux et al., 2010) [26]. We also discuss the influence of the cavity decay on the gate fidelity. It is shown that the fidelity of the phase gate is robust to the cavity decay and the high-fidelity quantum phase gate can be implemented with the current experimental technology. - Highlights: • A experimental feasible scheme for implementing two-qubit quantum phase gate. • Based on the dispersive interaction between the optical cavity mode and the symmetrically configurated three-level atoms. • Influence of the cavity decay on the gate fidelity is discussed.

  10. The architecture of neutrophil extracellular traps investigated by atomic force microscopy

    Science.gov (United States)

    Pires, Ricardo H.; Felix, Stephan B.; Delcea, Mihaela

    2016-07-01

    Neutrophils are immune cells that engage in a suicidal pathway leading to the release of partially decondensed chromatin, or neutrophil extracellular traps (NETs). NETs behave as a double edged sword; they can bind to pathogens thereby ensnaring them and limiting their spread during infection; however, they may bind to host circulating materials and trigger thrombotic events, and are associated with autoimmune disorders. Despite the fundamental role of NETs as part of an immune system response, there is currently a very poor understanding of how their nanoscale properties are reflected in their macroscopic impact. In this work, using a combination of fluorescence and atomic force microscopy, we show that NETs appear as a branching filament network that results in a substantially organized porous structure with openings with 0.03 +/- 0.04 μm2 on average and thus in the size range of small pathogens. Topological profiles typically up to 3 +/- 1 nm in height are compatible with a ``beads on a string'' model of nucleosome chromatin. Typical branch lengths of 153 +/- 103 nm appearing as rigid rods and height profiles of naked DNA in NETs of 1.2 +/- 0.5 nm are indicative of extensive DNA supercoiling throughout NETs. The presence of DNA duplexes could also be inferred from force spectroscopy and the occurrence of force plateaus that ranged from ~65 pN to 300 pN. Proteolytic digestion of NETs resulted in widespread disassembly of the network structure and considerable loss of mechanical properties. Our results suggest that the underlying structure of NETs is considerably organized and that part of its protein content plays an important role in maintaining its mesh architecture. We anticipate that NETs may work as microscopic mechanical sieves with elastic properties that stem from their DNA-protein composition, which is able to segregate particles also as a result of their size. Such a behavior may explain their participation in capturing pathogens and their association

  11. Effect of concurrent joule heat and charge trapping on RESET for NbAlO fabricated by atomic layer deposition.

    Science.gov (United States)

    Zhou, Peng; Ye, Li; Sun, Qing Qing; Wang, Peng Fei; Jiang, An Quan; Ding, Shi Jin; Zhang, David Wei

    2013-01-01

    The RESET process of NbAlO-based resistive switching memory devices fabricated by atomic layer deposition is investigated at low temperatures from 80 to 200 K. We observed that the conduction mechanism of high resistance state changed from hopping conduction to Frenkel-Poole conduction with elevated temperature. It is found that the conductive filament rupture in RRAM RESET process can be attributed not only to the Joule heat generated by internal current flow through a filament but also to the charge trap/detrapping effect. The RESET current decreases upon heating. Meanwhile, the energy consumption also decreases exponentially. This phenomenon indicates the temperature-related charge trap/detrapping process which contributes to the RESET besides direct Joule heat. PMID:23421401

  12. Chaotic atomic population oscillations between two coupled Bose-Einstein condensates with time-dependent asymmetric trap potential

    CERN Document Server

    Lee, C; Zhu, X; Gao, K; Hai, W; Duan Yi Shi; Liu, W K; Lee, Chaohong; Shi, Lei; Zhu, Xiwen; Gao, Kelin; Hai, Wenhua; Duan, Yiwu; Liu, Wing-Ki

    2001-01-01

    We have investigated the chaotic atomic population oscillations between two coupled Bose-Einstein condensates (BEC) with time-dependent asymmetric trap potential. In the perturbative regime, the population oscillations can be described by the Duffing equation, and the chaotic oscillations near the separatrix solution are analyzed. The sufficient-necessary conditions for stable oscillations depend on the physical parameters and initial conditions sensitively. The first-order necessary condition indicates that the Melnikov function is equal to zero, so the stable oscillations are Melnikov chaotic. For the ordinary parameters and initial conditions, the chaotic dynamics is simulated with numerical calculation. If the damping is absent, with the increasing of the trap asymmetry, the regular oscillations become chaotic gradually, the corresponding stroboscopic Poincare sections (SPS) vary from a single island to more islands, and then the chaotic sea. For the completely chaotic oscillations, the long-term localiza...

  13. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Custo, Graciela [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Litter, Marta I. [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Escuela de Posgrado, Universidad de General San Martin, San Lorenzo 3391 Villa Ballester, 1653. Prov. de Buenos Aires (Argentina); Rodriguez, Diana [Universidad Nacional de Lujan, Ruta 5 y 7. Prov. de Buenos Aires (Argentina); Vazquez, Cristina [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina) and Laboratorio de Quimica de Sistemas Heterogeneos, Facultad de Ingenieria, Universidad de Buenos Aires, P. Colon 850 (C1063ACU), Buenos Aires (Argentina)]. E-mail: Cristina.Vazquez@cnea.gov.ar

    2006-11-15

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 {mu}g/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO{sub 2}-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  14. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    Science.gov (United States)

    Custo, Graciela; Litter, Marta I.; Rodríguez, Diana; Vázquez, Cristina

    2006-11-01

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 μg/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO 2-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  15. Inelastic scattering of light by a cold trapped atom: Effects of the quantum center-of-mass motion

    CERN Document Server

    Bienert, M; Morigi, G; Bienert, Marc; Merkel, Wolfgang; Morigi, Giovanna

    2005-01-01

    The light scattered by a cold trapped ion, which is in the stationary state of laser cooling, presents features due to the mechanical effects of atom-photon interaction. These features appear as additional peaks (sidebands) in the spectrum of resonance fluorescence. Among these sidebands the literature has discussed the Stokes and anti-Stokes components, namely the sidebands of the elastic peak. In this manuscript we show that the motion also gives rise to sidebands of the inelastic peaks. These are not always visible, but, as we show, can be measured in parameter regimes which are experimentally accessible.

  16. Blue-detuned evanescent field surface traps for neutral atoms based on mode interference in ultra-thin optical fibres

    OpenAIRE

    Sague, G.; Baade, A.; Rauschenbeutel, A.

    2008-01-01

    We present and analyze a novel concept for blue-detuned evanescent field surface traps for cold neutral atoms based on two-mode interference in ultra-thin optical fibres. When two or more transverse modes with the same frequency co-propagate in the fibre, their different phase velocities cause a stationary interference pattern to establish. Intensity minima of the evanescent field at any distance from the fibre surface can be created and an array of optical microtraps can thus be obtained in ...

  17. Compact FPGA-based pulse-sequencer and radio-frequency generator for experiments with trapped atoms

    CERN Document Server

    Pruttivarasin, Thaned

    2015-01-01

    We present a compact FPGA-based pulse sequencer and radio-frequency (RF) generator suitable for experiments with cold trapped ions and atoms. The unit is capable of outputting a pulse sequence with at least 32 TTL channels with a timing resolution of 40 ns and contains a built-in 100 MHz frequency counter for counting electrical pulses from a photo-multiplier tube (PMT). There are 16 independent direct-digital-synthesizers (DDS) RF sources with fast (rise-time of ~60 ns) amplitude switching and sub-mHz frequency tuning from 0 to 800 MHz.

  18. Fast Non-destructive temperature measurement of two-electrons atoms in a magneto-optical trap

    OpenAIRE

    Cristiani, Matteo; Valenzuela, Tristan; Gothe, Hannes; Eschner, Jürgen

    2010-01-01

    We extend the technique originally proposed by Honda et al.to measure the temperature of Ytterbium and alkine-earth atoms confined in a Magneto-Optical Trap (MOT). The method is based on the analysis of excitation spectra obtained by probing the 1S0->3P1 inter-combination line. Thanks to a careful analysis and modeling of the effects caused by the MOT light on the probe transition we overcome the resolution and precision limits encountered in previous works. Ground state light shift and Rabi ...

  19. Compact field programmable gate array-based pulse-sequencer and radio-frequency generator for experiments with trapped atoms

    Energy Technology Data Exchange (ETDEWEB)

    Pruttivarasin, Thaned, E-mail: thaned.pruttivarasin@riken.jp [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Katori, Hidetoshi [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Innovative Space-Time Project, ERATO, JST, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-11-15

    We present a compact field-programmable gate array (FPGA) based pulse sequencer and radio-frequency (RF) generator suitable for experiments with cold trapped ions and atoms. The unit is capable of outputting a pulse sequence with at least 32 transistor-transistor logic (TTL) channels with a timing resolution of 40 ns and contains a built-in 100 MHz frequency counter for counting electrical pulses from a photo-multiplier tube. There are 16 independent direct-digital-synthesizers RF sources with fast (rise-time of ∼60 ns) amplitude switching and sub-mHz frequency tuning from 0 to 800 MHz.

  20. Investigations of the ground-state hyperfine atomic structure and beta decay measurement prospects of {sup 21}Na with improved laser trapping techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, Mary A.

    1999-05-24

    This thesis describes an experiment in which a neutral atom laser trap loaded with radioactive {sup 21}Na was improved and then used for measurements. The sodium isotope (half-life=22 sec) is produced on line at the 88in cyclotron at Lawrence Berkeley National Laboratory. The author developed an effective magnesium oxide target system which is crucial to deliver a substantive beam of {sup 21}Na to the experiment. Efficient manipulation of the {sup 21}Na beam with lasers allowed 30,000 atoms to be contained in a magneto-optical trap. Using the cold trapped atoms, the author measured to high precision the hyperfine splitting of the atomic ground state of {sup 21}Na. She measured the 3S{sub 1/2}(F=1,m=0)-3S{sub 1/2}(F=2,m=0) atomic level splitting of {sup 21}Na to be 1,906,471,870{+-}200 Hz. Additionally, she achieved initial detection of beta decay from the trap and evaluated the prospects of precision beta decay correlation studies with trapped atoms.

  1. Fast Non-destructive temperature measurement of two-electrons atoms in a magneto-optical trap

    CERN Document Server

    Cristiani, Matteo; Gothe, Hannes; Eschner, Jürgen

    2010-01-01

    We extend the technique originally proposed by Honda et al.to measure the temperature of Ytterbium and alkine-earth atoms confined in a Magneto-Optical Trap (MOT). The method is based on the analysis of excitation spectra obtained by probing the 1S0->3P1 inter-combination line. Thanks to a careful analysis and modeling of the effects caused by the MOT light on the probe transition we overcome the resolution and precision limits encountered in previous works. Ground state light shift and Rabi broadening are measured and successfully compared with calculated values. This knowledge allows us to properly extract the Doppler contribution to the linewidth, thus obtaining a reliable measurement of the cloud temperature. We finally show how spectroscopy on free-falling atoms provides an alternative method to determine the sample temperature which resembles the standard time-of-flight technique.

  2. TRI mu P - A new facility to investigate fundamental interactions with optically trapped radioactive atoms

    NARCIS (Netherlands)

    Jungmann, K

    2002-01-01

    At the Kernfysisch Versneller Instituut (KVI) in Groningen, NL, a new facility (TRImuP) is under development. It aims for producing, slowing down and trapping of radioactive isotopes in order to perform accurate measurements on fundamental symmetries and interactions. A spectrum of radioactive nucli

  3. Born-Oppenheimer description of two atoms in a combined oscillator and lattice trap

    DEFF Research Database (Denmark)

    Sørensen, Ole Søe; Mølmer, Klaus

    2012-01-01

    We analyze the quantum states of two identical bosons in a combined harmonic oscillator and periodic lattice trap in one spatial dimension. In the case of tight-binding and only nearest-neighbor tunneling, the equations of motion are conveniently represented in the momentum representation. We show...

  4. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  5. Inductively coupled plasma--atomic emission spectrometry: trace elements in oil matrices

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, C. A.

    1977-12-01

    The simultaneous determination of up to 20 trace elements in various oil matrices by inductively coupled plasma-atomic emission spectrometry is reported. The oil matrices investigated were lubricating oils (for wear metals), fuel oil, centrifuged coal liquefaction product, crude soybean oil, and commercial edible oils. The samples were diluted with appropriate organic solvents and injected into the plasma as an aerosol generated by a pneumatic nebulization technique. Detection limits of the 28 elements studied ranged from 0.0006 to 9 ..mu..g/g with the majority falling in the 0.01 to 0.1 ..mu..g/g range. Analytical calibration curves were linear over at least two orders of magnitude and for some elements this linearity extended over 4.5 orders of magnitude. Relevant data on precision and accuracy are included. Because metals often occur as particles in lubricating oil and coal liquefaction products, the effect of particles on the analytical results was examined. Wear metal particles in used oil did not appear to affect the analytical results. However, incomplete recovery relative to organometallic reference solutions was obtained for iron particles with a nominal mean diameter of 3.0 ..mu..m suspended in oil. It was shown that the following factors contributed to incomplete recovery for the particles: settling of the suspended particles in the flask, a difference in nebulization efficiency between particle suspensions and organometallic solutions, and indications of incomplete vaporization of the larger particles in the plasma.

  6. Determination of eight trace elements in doped crystal ALN by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. In this paper, an accurate and simple method has been developed for the determination of trace Cr, Co, Cu, Fe, Mg, Mn ,Ni and Zn in doped AlN crystal using inductively coupled plasma atomic emission spectrometry (ICP-AES). AlN crystal becomes ideal substrate for the epitaxial growth of GaN, AlGaN with high Al ingredient and AlN which are used to fabricate ultraviolet LEDs, blue- ultraviolet solid state LDs, lasers, ultraviolet detectors. At present, It is a very important aspect for scientific workers to promote in the transition metals elements doped AlN showing ferromagne. Owing its low detection limits and multi-element capability, ICP-AES has been used in many fields.The optimum instrument working conditions are selected .AlN crystal was fused with KOH and the fusion product was dissolved in dilute aqua regia. Matrix effect from KOH and interference to the spectral lines of the elements to be determined were investigated and corrected by matrix matching and background correction method. Detection limits of elements were 0.01% to 0.0002% The recoveries for elements were 98% to 104%. The relative standard deviation was 0.5% to 4.0%.

  7. An atomic beam source for fast loading of a magneto-optical trap under high vacuum

    DEFF Research Database (Denmark)

    McDowall, P.D.; Hilliard, Andrew; Grünzweig, T.;

    2012-01-01

    We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By applying a high current (15 A) pulse to the dispenser at room temperature we can rapidly heat it to a temperature at which it starts dispensing, avoiding the need for preheating. The atomic beam produced...

  8. Trapping a single atom with a fraction of a photon using a photonic crystal nanocavity

    NARCIS (Netherlands)

    van Oosten, D.; Kuipers, L.

    2011-01-01

    We consider the interaction between a single rubidium atom and a photonic crystal nanocavity. Because of the ultrasmall mode volume of the nanocavity, an extremely strong coupling regime can be achieved in which the atom can shift the cavity resonance by many cavity linewidths. We show that this shi

  9. Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

    International Nuclear Information System (INIS)

    The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

  10. Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

    Energy Technology Data Exchange (ETDEWEB)

    Sanguinetti, St

    2004-07-01

    The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

  11. Nobel Prize in Physics 1997 "for development of methods to cool and trap atoms with laser light" : Steven Chu, Claude Cohen-Tannoudji and William D. Phillips

    CERN Multimedia

    Audiovideo service

    1998-01-01

    Prof. C. Cohen-Tannoudji presents "manipulating atoms with light" . By using quasi-resonant exchanges of energy, linear and angular momentum between atoms and photons, it is possible to polarize atoms, to displace their energy levels and to control their position and their velocity. A few physical mechanisms allowing one to trap atoms and to cool them in the microKelvin, and even in the nanoKelvin range, will be described. Various possible applications of such ultracold atoms will be also reviewed.

  12. [Determination of trace elements in Lophatherum gracile brongn from different habitat by microwave digestion-atomic absorption spectroscopy].

    Science.gov (United States)

    Yuan, Ke; Xue, Yue-Qin; Gui, Ren-Yi; Sun, Su-Qin; Yin, Ming-Wen

    2010-03-01

    A method of microwave digestion technique was proposed to determine the content of Zn, Fe, Cu, Mn, K, Ca, Mg, Ni, Cd, Pb, Cr, Co, Al, Se and As in Lophatherum gracile brongn of different habitat by atomic absorption spectroscopy. The RSD of the method was between 1.23% and 3.32%, and the recovery rates obtained by standard addition method were between 95.8% and 104.20%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of metal elements in Lophatherum gracile brongn. The experimental results also indicated that different areas' Lophantherum gracile brongn had different trace elements content. The content of trace elements K, Mg, Ca, Fe and Mn beneficial to the human body was rich. The content of the heavy metal trace element Pb in Lophantherum gracile brongn of Hunan province was slightly high. The content of the heavy metal trace element Cu in Lophantherum gracile brongn of Guangdong province and Anhui province is also slightly higher. Beside, the contents of harmful trace heavy metal elements Cd, Cu, Cr, Pb and As in Lophatherum gracile brongn of different habitat are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation and National Food Sanitation Standard. These determination results provided the scientific data for further discussing the relationship between the content of trace elements in Lophantherum gracile brongn and the medicine efficacy.

  13. High efficiency preparation of single trapped atoms using blue detuned light assisted collisions

    CERN Document Server

    Carpentier, A V; Sompet, P; Hilliard, A J; Walker, T G; Andersen, M F

    2012-01-01

    We report on a procedure by which we obtain a 91% loading efficiency of single 85Rb atoms in an optical microtrap. This can be achieved within a total preparation time of 542 ms. We employ blue detuned light assisted collisions to realize a process in which only one of the collision partners is lost. We explain the mechanism for efficiently loading a single atom and discuss the factors that limit the final efficiency.

  14. Dispersive response of atoms trapped near the surface of an optical nanofiber with applications to quantum nondemolition measurement and spin squeezing

    Science.gov (United States)

    Qi, Xiaodong; Baragiola, Ben Q.; Jessen, Poul S.; Deutsch, Ivan H.

    2016-02-01

    We study the strong coupling between photons and atoms that can be achieved in an optical nanofiber geometry when the interaction is dispersive. While the Purcell enhancement factor for spontaneous emission into the guided mode does not reach the strong-coupling regime for individual atoms, one can obtain high cooperativity for ensembles of a few thousand atoms due to the tight confinement of the guided modes and constructive interference over the entire chain of trapped atoms. We calculate the dyadic Green's function, which determines the scattering of light by atoms in the presence of the fiber, and thus the phase shift and polarization rotation induced on the guided light by the trapped atoms. The Green's function is related to a full Heisenberg-Langevin treatment of the dispersive response of the quantized field to tensor polarizable atoms. We apply our formalism to quantum nondemolition (QND) measurement of the atoms via polarimetry. We study shot-noise-limited detection of atom number for atoms in a completely mixed spin state and the squeezing of projection noise for atoms in clock states. Compared with squeezing of atomic ensembles in free space, we capitalize on unique features that arise in the nanofiber geometry including anisotropy of both the intensity and polarization of the guided modes. We use a first-principles stochastic master equation to model the squeezing as a function of time in the presence of decoherence due to optical pumping. We find a peak metrological squeezing of ˜5 dB is achievable with current technology for ˜2500 atoms trapped 180 nm from the surface of a nanofiber with radius a =225 nm.

  15. Compartmentalization of trace elements in guinea pig tissues by INAA [instrumental neutron activation analysis] and AAS [atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Human scalp hair analysis has received considerable attention from a variety of disciplines over the last 20 yr or so. Trace element levels of hair have been used in environmental, epidemiological, forensic, nutritional, predictive, and preventive medicine studies. There still exist confusion, skepticism, and controversy, however, among the experts as well as lay persons in the interpretation of hair trace element data. Much of the criticism stems from the lack of quantitative and reliable data on the ability of hair to accurately reflect dose-response relationships. To better define the significance or hair trace element levels (under the auspices of the International Atomic Energy Agency), the authors have undertaken a controlled set of animal experiments in which trace element levels in hair and other tissues have been measured after a mild state of systemic intoxication by chronic, low-does exposure to cadmium and selenium. Instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS) methods have been developed for the determination of several elements with a high degree of precision and accuracy

  16. Critical temperature of Bose-Einstein condensation in trapped atomic Bose-Fermi mixtures

    International Nuclear Information System (INIS)

    We calculate the shift in the critical temperature of Bose-Einstein condensation for a dilute Bose-Fermi mixture confined by a harmonic potential, to lowest order in both the Bose-Bose and Bose-Fermi coupling constants. The relative importance of the effect on the critical temperature of the boson-boson and boson-fermion interactions is investigated as a function of the parameters of the mixture. The possible relevance of the shift of the transition temperature in current experiments on trapped Bose-Fermi mixtures is discussed. (letter to the editor)

  17. Critical temperature of Bose-Einstein condensation in trapped atomic Bose-Fermi mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Albus, A P [Institut fuer Physik, Universitaet Potsdam, D-14469 Potsdam (Germany); Giorgini, S [Dipartimento di Fisica, Universita di Trento, and Istituto Nazionale per la Fisica della Materia, I-38050 Povo (Italy); Illuminati, F [Dipartimento di Fisica, Universita di Salerno, and Istituto Nazionale per la Fisica della Materia, I-84081 Baronissi (Italy); Viverit, L [Dipartimento di Fisica, Universita di Trento, and Istituto Nazionale per la Fisica della Materia, I-38050 Povo (Italy)

    2002-12-14

    We calculate the shift in the critical temperature of Bose-Einstein condensation for a dilute Bose-Fermi mixture confined by a harmonic potential, to lowest order in both the Bose-Bose and Bose-Fermi coupling constants. The relative importance of the effect on the critical temperature of the boson-boson and boson-fermion interactions is investigated as a function of the parameters of the mixture. The possible relevance of the shift of the transition temperature in current experiments on trapped Bose-Fermi mixtures is discussed. (letter to the editor)

  18. Coherent Population Trapping Resonances in Cs Atomic Vapor Layers of Micrometric Thickness

    Directory of Open Access Journals (Sweden)

    A. Krasteva

    2011-01-01

    Full Text Available We report on a novel behavior of the electromagnetically induced absorption (EIA resonance observed on the D2 line of Cs for atoms confined in cells with micrometric thickness. With the enhancement of light intensity, the EIA resonance amplitude suffers from fast reduction, and even at very low intensity (W < 1 mW/cm2, resonance sign reversal takes place and electromagnetically induced transparency (EIT resonance is observed. Similar EIA resonance transformation to EIT one is not observed in conventional cm-size cells. A theoretical model is proposed to analyze the physical processes behind the EIA resonance sign reversal with light intensity. The model involves elastic interactions between Cs atoms as well as elastic interaction of atom micrometric-cell windows, both resulting in depolarization of excited state which can lead to the new observations. The effect of excited state depolarization is confirmed also by the fluorescence (absorption spectra measurement in micrometric cells with different thicknesses.

  19. Decay of a superfluid current of ultracold atoms in a toroidal trap

    Science.gov (United States)

    Mathey, Amy C.; Clark, Charles W.; Mathey, L.

    2014-08-01

    Using a numerical implementation of the truncated Wigner approximation, we simulate the experiment reported by Ramanathan et al. in Phys. Rev. Lett. 106, 130401 (2011), 10.1103/PhysRevLett.106.130401, in which a Bose-Einstein condensate is created in a toroidal trap and set into rotation via a phase imprinting technique. A potential barrier is then placed in the trap to study the decay of the superflow. We find that the current decays via thermally activated phase slips, which can also be visualized as vortices crossing the barrier region in the radial direction. Adopting the notion of critical velocity used in the experiment, we determine it to be lower than the local speed of sound at the barrier, in contradiction to the predictions of the zero-temperature Gross-Pitaevskii equation. We map out the superfluid decay rate and critical velocity as a function of temperature and observe a strong dependence. Thermal fluctuations offer a partial explanation of the experimentally observed reduction of the critical velocity from the phonon velocity.

  20. Analysis of trace element in intervertebral disc by Atomic Absorption Spectrometry techniques in degenerative disc disease in the Polish population

    Directory of Open Access Journals (Sweden)

    Andrzej Nowakowski

    2015-05-01

    Full Text Available Objective. Although trace elements are regarded crucial and their content has been determined in number of tissue there are only few papers addressing this problem in intervertebral disc in humans. Most of the trace elements are important substrates of enzymes influencing metabolism and senescence process. Others are markers of environmental pollution. Therefore the aim of the research was to analyzed of the trace element content in the intervertebral disc, which may be a vital argument recognizing the background of degenerative changes to be the effect of the environment or metabolic factors. Materials and methods. Material consist of 18 intervertebral disc from 15 patients, acquired in surgical procedure of due to the degenerative disease with Atomic Absorption Spectrometry content of Al, Cd, Co, Pb, Cu, Ni, Mo, Mg, Zn was evaluated. Results. Only 4 of the trace elements were detected in all samples. The correlation analysis showed significant positive age correlation with Al and negative in case of Co. Among elements significant positive correlation was observed between Al/Pb, Co/Mo, Al/Mg, Al/Zn Pb/Zn and Mg/Zn. Negative correlation was observed in Al/Co, Cd/Mg, Co/Mg, Mo/Mg, Co/Zn and Mo/Zn. Conclusions. This study is the first to our knowledge that profiles the elements in intervertebral disc in patients with degenerative changes. We have confirmed significant differences between the trace element contents in intervertebral disc and other tissue. It can be ground for further investigation.

  1. Spectroscopy of ^1S0 -- ^3P1^88Sr Atomic Transition in a 1.06 μm Optical Dipole Trap

    Science.gov (United States)

    Martinez de Escobar, Y. N.; Mickelson, P. G.; Traverso, A. J.; Killian, T. C.

    2008-05-01

    We studied the effects of laser light near-resonant with the ^1S0-- ^3P1^88Sr transition in an optical dipole trap (ODT). We observe laser cooling of our ODT atomic sample as the atoms collide in the presence of red-detuned 689 nm light. Heating of the atoms was also observed at a different range of frequency detunings while performing spectroscopy. Both processes were accompanied with atom loss, but the increase of phase space density observed during 689 nm laser cooling could aid pursuits of quantum degeneracy with Sr.

  2. Ion-neutral chemistry at ultralow energies: Dynamics of reactive collisions between laser-cooled Ca^+ ions and Rb atoms in an ion-atom hybrid trap

    CERN Document Server

    Hall, Felix H J; Hegi, Gregor; Raoult, Maurice; Aymar, Mireille; Dulieu, Olivier; Willitsch, Stefan

    2013-01-01

    Cold chemical reactions between laser-cooled Ca^+ ions and Rb atoms were studied in an ion-atom hybrid trap. Reaction rate constants were determined in the range of collision energies /k_B = 20 mK-20 K. The lowest energies were achieved in experiments using single localized Ca^+ ions. Product branching ratios were studied using resonant-excitation mass spectrometry. The dynamics of the reactive processes in this system (non-radiative and radiative charge transfer as well as radiative association leading to the formation of CaRb^+ molecular ions) have been analyzed using high-level quantum-chemical calculations of the potential energy curves of CaRb^+ and quantum-scattering calculations for the radiative channels. For the present low-energy scattering experiments, it is shown that the energy dependence of the reaction rate constants is governed by long-range interactions in line with the classical Langevin model, but their magnitude is determined by short-range non-adiabatic and radiative couplings which only ...

  3. Vegetation and Cold Trapping Modulating Elevation-dependent Distribution of Trace Metals in Soils of a High Mountain in Eastern Tibetan Plateau

    Science.gov (United States)

    Bing, Haijian; Wu, Yanhong; Zhou, Jun; Li, Rui; Luo, Ji; Yu, Dong

    2016-04-01

    Trace metals adsorbed onto fine particles can be transported long distances and ultimately deposited in Polar Regions via the cold condensation effect. This study indicated the possible sources of silver (Ag), cadmium (Cd), copper (Cu), lead (Pb), antimony (Sb) and zinc (Zn) in soils on the eastern slope of Mt. Gongga, eastern Tibetan Plateau, and deciphered the effects of vegetation and mountain cold condensation on their distributions with elevation. The metal concentrations in the soils were comparable to other mountains worldwide except the remarkably high concentrations of Cd. Trace metals with high enrichment in the soils were influenced from anthropogenic contributions. Spatially, the concentrations of Cu and Zn in the surface horizons decreased from 2000 to 3700 m a.s.l., and then increased with elevation, whereas other metals were notably enriched in the mid-elevation area (approximately 3000 m a.s.l.). After normalization for soil organic carbon, high concentrations of Cd, Pb, Sb and Zn were observed above the timberline. Our results indicated the importance of vegetation in trace metal accumulation in an alpine ecosystem and highlighted the mountain cold trapping effect on trace metal deposition sourced from long-range atmospheric transport.

  4. Evaporative cooling of cesium atoms in the gravito-optical surface trap

    CERN Document Server

    Hammes, M; Grimm, R

    2000-01-01

    We report on cooling of an atomic cesium gas closely above an evanescent-wave. Our first evaporation experiments show a temperature reduction from 10muK down to 300nK along with a gain in phase-space density of almost two orders of magnitude. In a series of measurements of heating and spin depolarization an incoherent background of resonant photons in the evanescent-wave diode laser light was found to be the limiting factor at this stage.

  5. Internal Josephson-like tunnelling in two-component Bose-Einstein condensates affected by sign of the atomic interaction and external trapping potential

    Institute of Scientific and Technical Information of China (English)

    Xiong Bo; Liu Xun-Xu

    2007-01-01

    This paper studies the Josephson-like tunnelling in two-component Bose-Einstein condensates coupled with microwave field, which is in respond to various attractive and repulsive atomic interaction under the various aspect ratio of trapping potential. It is very interesting to find that the dynamic of Josephson-like tunnelling can be controlled from fast damped oscillations to nondamped oscillation, and relative number of atoms changes from asymmetric occupation to symmetric occupation correspondingly.

  6. [Determination of trace elements in Lophatherum gracile brongn from different habitat by microwave digestion-atomic absorption spectroscopy].

    Science.gov (United States)

    Yuan, Ke; Xue, Yue-Qin; Gui, Ren-Yi; Sun, Su-Qin; Yin, Ming-Wen

    2010-03-01

    A method of microwave digestion technique was proposed to determine the content of Zn, Fe, Cu, Mn, K, Ca, Mg, Ni, Cd, Pb, Cr, Co, Al, Se and As in Lophatherum gracile brongn of different habitat by atomic absorption spectroscopy. The RSD of the method was between 1.23% and 3.32%, and the recovery rates obtained by standard addition method were between 95.8% and 104.20%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of metal elements in Lophatherum gracile brongn. The experimental results also indicated that different areas' Lophantherum gracile brongn had different trace elements content. The content of trace elements K, Mg, Ca, Fe and Mn beneficial to the human body was rich. The content of the heavy metal trace element Pb in Lophantherum gracile brongn of Hunan province was slightly high. The content of the heavy metal trace element Cu in Lophantherum gracile brongn of Guangdong province and Anhui province is also slightly higher. Beside, the contents of harmful trace heavy metal elements Cd, Cu, Cr, Pb and As in Lophatherum gracile brongn of different habitat are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation and National Food Sanitation Standard. These determination results provided the scientific data for further discussing the relationship between the content of trace elements in Lophantherum gracile brongn and the medicine efficacy. PMID:20496714

  7. Determination of Pb in Biological Samples by Graphite Furnace Atomic Absorption Spectrophotometry: An Exercise in Common Interferences and Fundamental Practices in Trace Element Determination

    Science.gov (United States)

    Spudich, Thomas M.; Herrmann, Jennifer K.; Fietkau, Ronald; Edwards, Grant A.

    2004-01-01

    An experiment is conducted to ascertain trace-level Pb in samples of bovine liver or muscle by applying graphite furnace atomic absorption spectrophotometry (GFAAS). The primary objective is to display the effects of physical and spectral intrusions in determining trace elements, and project the usual methods employed to minimize accuracy errors…

  8. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Abdollahi Atousa

    2014-07-01

    Full Text Available A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap. The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS. The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically investigated. The factors influencing, the complex formation and extraction of DLLME-SFO method such as type and volume of extraction and disperser solvents, pH, concentration of salt, centrifuging time and concentration of the chelating agent were optimized. The method was successfully applied to the determination of mercury in drinking and natural water and satisfactory relative recoveries (95–105% were achieved. The proposed procedure was based on very low consumption of organic solvents. The other benefits of the system were sensitive, simple, friendly to the environment, rejection of matrix constituent, low cost, the time consuming and high enrichment factor.

  9. An effective analytical system based on a pulsed direct current microplasma source for ultra-trace mercury determination using gold amalgamation cold vapor atomic emission spectrometry

    International Nuclear Information System (INIS)

    A novel analysis system based on a low power atmospheric pressure pulsed direct current (Pdc) microplasma is described for the determination of ultra-trace mercury in natural water by cold vapor generation atomic emission spectrometry (CV-AES). The plasma was generated with a miniaturized home-built high-voltage Pdc power supply which decreased the volume and weight of the whole experiment setup. The CV-Pdc-AES system is based on the preconcentration of mercury vapor on a gold filament trapping micro-column prior to detection that provides fast, reproducible absorption and desorption of mercury. The micro-column is produced by winding 30 μm diameter 100 m long gold filament to a small ball and then insert it into a quartz tube of 6 mm i.d, 8 mm o.d. Under the optimized experimental conditions, the new system provides high sensitivity (detection limit: 0.08 pg mL−1) and good reproducibility (RSD 3.0%, [Hg] = 20 pg mL−1, n = 11). The calibration curve is linear at levels near the detection limit up to at least 200 pg mL−1 and the accuracy is on the order of 1–4%. The proposed method was applied to 5 real water samples for mercury ultra-trace analysis. The advantages and features of the newly developed system include high sensitivity, simple structure, low cost, and compact volume with field portable potential. - Highlights: • A novel system based on a low power pulsed dc microplasma for mercury detection. • A small home-built pulsed dc power supply was used to ignite the microplasma. • A gold filament preconcentrator followed by thermal desorption was used. • A detection limit of 0.08 pg mL−1 was achieved for sensitive mercury detection. • The system is compact, low power, and has potential for field portable application

  10. An effective analytical system based on a pulsed direct current microplasma source for ultra-trace mercury determination using gold amalgamation cold vapor atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xin [Research Center of Analytical Instrumentation, Analytical Testing Center, College of Chemistry, Sichuan University, Chengdu (China); Yang, Guang; Ding, Yu [College of Instrumentation and Electrical Engineering, Jilin University, Changchun (China); Li, Xuemei; Zhan, Xuefang; Zhao, Zhongjun [Research Center of Analytical Instrumentation, Analytical Testing Center, College of Chemistry, Sichuan University, Chengdu (China); Duan, Yixiang, E-mail: yduan@scu.edu.cn [Research Center of Analytical Instrumentation, Analytical Testing Center, College of Chemistry, Sichuan University, Chengdu (China)

    2014-03-01

    A novel analysis system based on a low power atmospheric pressure pulsed direct current (Pdc) microplasma is described for the determination of ultra-trace mercury in natural water by cold vapor generation atomic emission spectrometry (CV-AES). The plasma was generated with a miniaturized home-built high-voltage Pdc power supply which decreased the volume and weight of the whole experiment setup. The CV-Pdc-AES system is based on the preconcentration of mercury vapor on a gold filament trapping micro-column prior to detection that provides fast, reproducible absorption and desorption of mercury. The micro-column is produced by winding 30 μm diameter 100 m long gold filament to a small ball and then insert it into a quartz tube of 6 mm i.d, 8 mm o.d. Under the optimized experimental conditions, the new system provides high sensitivity (detection limit: 0.08 pg mL{sup −1}) and good reproducibility (RSD 3.0%, [Hg] = 20 pg mL{sup −1}, n = 11). The calibration curve is linear at levels near the detection limit up to at least 200 pg mL{sup −1} and the accuracy is on the order of 1–4%. The proposed method was applied to 5 real water samples for mercury ultra-trace analysis. The advantages and features of the newly developed system include high sensitivity, simple structure, low cost, and compact volume with field portable potential. - Highlights: • A novel system based on a low power pulsed dc microplasma for mercury detection. • A small home-built pulsed dc power supply was used to ignite the microplasma. • A gold filament preconcentrator followed by thermal desorption was used. • A detection limit of 0.08 pg mL{sup −1} was achieved for sensitive mercury detection. • The system is compact, low power, and has potential for field portable application.

  11. Quantification of minerals and trace elements in raw caprine milk using flame atomic absorption spectrophotometry and flame photometry.

    Science.gov (United States)

    Singh, Mahavir; Yadav, Poonam; Garg, V K; Sharma, Anshu; Singh, Balvinder; Sharma, Himanshu

    2015-08-01

    This study reports minerals and trace elements quantification in raw caprine milk of Beetal breed, reared in Northern India and their feed, fodder & water using flame atomic absorption spectrophotometry and flame photometry. The mineral and trace elements' concentration in the milk was in the order: K > Ca > Na > Fe > Zn > Cu. The results showed that minerals concentration in caprine milk was lesser than reference values. But trace elements concentration (Fe and Zn) was higher than reference values. Multivariate statistical techniques, viz., Pearsons' correlation, Cluster analysis (CA) and Principal component analysis (PCA) were applied to analyze the interdependences within studied variables in caprine milk. Significantly positive correlations were observed between Fe - Zn, Zn - K, Ca - Na and Ca - pH. The results of correlation matrix were further supported by Cluster analysis and Principal component analysis as primary cluster pairs were found for Ca - pH, Ca - Na and Fe - Zn in the raw milk. No correlation was found between mineral & trace elements content of the milk and feed. PMID:26243956

  12. Narrow Na and K Absorption Lines Toward T Tauri Stars - Tracing the Atomic Envelope of Molecular Clouds

    CERN Document Server

    Pascucci, I; Heyer, M; Rigliaco, E; Hillenbrand, L; Gorti, U; Hollenbach, D; Simon, M N

    2015-01-01

    We present a detailed analysis of narrow of NaI and KI absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The NaI 5889.95 angstrom line is detected toward all but one source, while the weaker KI 7698.96 angstrom line in about two thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present towards both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of NaI and CO detections and peak centroids demonstrates that the atomic and molecular gas are not co-located, the atomic gas is more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of NaI radial velocities shows a c...

  13. Laser frequency locking with 46 GHz offset using an electro-optic modulator for magneto-optical trapping of francium atoms

    CERN Document Server

    Harada, K; Ezure, S; Kato, K; Hayamizu, T; Kawamura, H; Inoue, T; Arikawa, H; Ishikawa, T; Aoki, T; Uchiyama, A; Sakamoto, K; Ito, S; Itoh, M; Ando, S; Hatakeyama, A; Hatanaka, K; Imai, K; Murakami, T; Nataraj, H S; Shimizu, Y; Sato, T; Wakasa, T; Yoshida, H P; Sakemi, Y

    2016-01-01

    We demonstrated a frequency offset locking between two laser sources using a waveguide-type electro-optic modulator (EOM) with 10th-order sidebands for magneto-optical trapping of Fr atoms. The frequency locking error signal was successfully obtained by performing delayed self-homodyne detection of the beat signal between the repumping frequency and the 10th-order sideband component of the trapping light. Sweeping the trapping-light and repumping-light frequencies with keeping its frequency difference of 46 GHz was confirmed over 1 GHz by monitoring the Doppler absorption profile of I2. This technique enables us to search for a resonance frequency of magneto-optical trapping of Fr.

  14. Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes (MWCNTs) and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry. The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing. Parameters influencing the recoveries of target analytes were optimized. Under optimal conditions, the target analyte exhibited a good linearity (R2=0.9992)over the concentration range 0.5-50 ng/ml. The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%,respectively. The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%. All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.

  15. Application of potential harmonic expansion method to BEC: Thermodynamic properties of trapped 23Na atoms

    Indian Academy of Sciences (India)

    Anasuya Kundu; Barnali Chakrabarti; Tapan Kumar Das

    2005-07-01

    We adopt the potential harmonics expansion method for an ab initio solution of the many-body system in a Bose condensate containing interacting bosons. Unlike commonly adopted mean-field theories, our method is capable of handling two-body correlation properly. We disregard three- and higher-body correlations. This simplification is ideally suited to dilute Bose Einstein condensates, whose number density is required to be so small that the interparticle separation is much larger than the range of two-body interaction to avoid three- and higher-body collisions, leading to the formation of molecules and consequent instability of the condensate. In our method we can incorporate realistic finite range interactions. We calculate energies of low-lying states of a condensate containing 23Na atoms and some thermodynamical properties of the condensate.

  16. Rydberg-induced optical nonlinearities from a cold atomic ensemble trapped inside a cavity

    Science.gov (United States)

    Boddeda, R.; Usmani, I.; Bimbard, E.; Grankin, A.; Ourjoumtsev, A.; Brion, E.; Grangier, P.

    2016-04-01

    We experimentally characterize the optical nonlinear response of a cold atomic medium placed inside an optical cavity, and excited to Rydberg states. The excitation to S and D Rydberg levels is carried out via a two-photon transition in an electromagnetically induced transparency configuration, with a weak (red) probe beam on the lower transition, and a strong (blue) coupling beam on the upper transition. The observed optical nonlinearities induced by S states for the probe beam can be explained using a semi-classical model with van der Waals’ interactions. For the D states, it appears necessary to take into account a dynamical decay of Rydberg excitations into a long-lived dark state. We show that the measured nonlinearities can be explained by using a Rydberg bubble model with a dynamical decay.

  17. Rydberg-induced optical nonlinearities from a cold atomic ensemble trapped inside a cavity

    CERN Document Server

    Boddeda, Rajiv; Bimbard, Erwan; Grankin, Andrey; Ourjoumtsev, Alexei; Brion, Etienne; Grangier, Philippe

    2015-01-01

    We experimentally characterize the optical nonlinear response of a cold atomic medium placed inside an optical cavity, and excited to Rydberg states. The excitation to S and D Rydberg levels is carried out via a two-photon transition in an EIT (electromagnetically induced transparency) configuration, with a weak (red) probe beam on the lower transition, and a strong (blue) coupling beam on the upper transition. The observed optical nonlinearities induced by S states for the probe beam can be explained using a semi-classical model with van der Waals' interactions. For the D states, it appears necessary to take into account a dynamical decay of Rydberg excitations into a long-lived dark state. We show that the measured nonlinearities can be explained by using a Rydberg bubble model with a dynamical decay.

  18. Flame atomic absorption spectrometric determinations of some trace metals after coprecipitation with gold-APDC

    International Nuclear Information System (INIS)

    Complete text of publication follows. For the determination of trace metals in various samples, preconcentration is an inevitable step to overcome interferences. Among various techniques for the separation of trace metals proposed until now, coprecipitation is one of the most useful ones. Many different coprecipitation procedures including use of organic and inorganic collectors have been developed. So far, in the literature, it is reported that APDC, NaDDTC, PAN, TAR, Oxine, etc. as chelating agent for metal-chelate collector have been extensively used for coprecipitation of trace metals. However, metal chelates, especially dithocarbamates, as collectors are ideal for their sensitivities, simplicities and tolerances to interferences.Therefore, in the present work, fundamental studies on the coprecipitation with gold/APDC chelate have been carried out for determination of trace metals in environmental samples by FAAS with microinjection. According to our literature survey, gold/APDC is not used for the coprecipitation of heavy metal ions, until now. In this work, the coprecipitation was carried out in a centrifuge tube. Firstly, the main factors, such as amount of coprecipitant reagent and carrier element, pH of the solution, standing time, sample volume and diverse ions, affecting the coprecipitation of some trace metals were evaluated. Under optimized conditions, the recoveries of Cu, Ni, Pb and Cd were ≥ 95 %. R.S.D. values for ten replicates were lower than 5.0 %. Preconcentration factors were found to be 20. The coprecipitation was applied to various water samples and non-alcoholic beverage.

  19. Generalized gradient expansion for inhomogeneous dynamical mean-field theory: Application to ultracold atoms in a harmonic trap

    Science.gov (United States)

    Freericks, J. K.; Han, Shuyang; Mikelsons, Karlis; Krishnamurthy, H. R.

    2016-08-01

    We develop a generalized gradient expansion of the inhomogeneous dynamical mean-field theory method for determining properties of ultracold atoms in a trap. This approach goes beyond the well-known local density approximation and at higher temperatures, in the normal phase, it shows why the local density approximation works so well, since the local density and generalized gradient approximations are essentially indistinguishable from each other (and from the exact solution within full inhomogeneous dynamical mean-field theory). But because the generalized gradient expansion only involves nearest-neighbor corrections, it does not work as well at low temperatures, when the systems enter into ordered phases. This is primarily due to the problem that ordered phases often satisfy some global constraints, which determine the spatial ordering pattern, and the local density and generalized gradient approximations are not able to impose those kinds of constraints; they also overestimate the tendency to order. The theory is applied to phase separation of different mass fermionic mixtures represented by the Falicov-Kimball model and to determining the entropy per particle of a fermionic system represented by the Hubbard model. The generalized gradient approximation is a useful diagnostic for the accuracy of the local density approximation—when both methods agree, they are likely accurate, when they disagree, neither is likely to be correct.

  20. Determination of traces of cadmium in zinc by flameless atomic absorption spectrophotometry after extraction

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, A.; Willmann, K.H.; Simon, F.J.

    1985-01-01

    The suitability of dithizone, diethyldithiocarbamate and tetramethylendithiocarbamate as chelating agents for the extraction-photometric cadmium determination by flameless atomic absorption spectrophotometry in the presence of zinc was investigated. It has been found that the extraction of the dithizone chelate by carbon tetrachloride permits an uninfluenced determination of cadmium in the presence of a zinc excess up to 10/sup 5/. Therefore the use of flameless atomic absorption spectrophotometry raises the selectivity as compared to photometry, because photometry only permits a 1000-fold excess of zinc. With this method 2x10/sup -4/% of cadmium in zinc can be determined without further corrections of matrix effects.

  1. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bentlin, Fabrina R.S. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Pozebon, Dirce [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil)], E-mail: dircepoz@iq.ufrgs.br; Mello, Paola A.; Flores, Erico M.M. [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900 Santa Maria, RS (Brazil)

    2007-10-17

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO{sub 3}){sub 2} was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 {mu}g g{sup -1} of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

  2. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Bentlin, Fabrina R S; Pozebon, Dirce; Mello, Paola A; Flores, Erico M M

    2007-10-17

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO3)2 was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 microg g(-1) of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES).

  3. Trapped antihydrogen

    CERN Document Server

    Butler, E; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jonsell, S; Jørgensen, L V; Kemp, S L; Kurchaninov, L; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Seif el Nasr, S; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki,Y

    2012-01-01

    Precision spectroscopic comparison of hydrogen and antihydrogen holds the promise of a sensitive test of the Charge-Parity-Time theorem and matter-antimatter equivalence. The clearest path towards realising this goal is to hold a sample of antihydrogen in an atomic trap for interrogation by electromagnetic radiation. Achieving this poses a huge experimental challenge, as state-of-the-art magnetic-minimum atom traps have well depths of only ∼1 T (∼0.5 K for ground state antihydrogen atoms). The atoms annihilate on contact with matter and must be ‘born’ inside the magnetic trap with low kinetic energies. At the ALPHA experiment, antihydrogen atoms are produced from antiprotons and positrons stored in the form of non-neutral plasmas, where the typical electrostatic potential energy per particle is on the order of electronvolts, more than 104 times the maximum trappable kinetic energy. In November 2010, ALPHA published the observation of 38 antiproton annihilations due to antihydrogen atoms that had been ...

  4. Study on the application of cold vapor atomic absorption spectrometry and hydride generation atomic absorption spectrometry for the determination of Hg and As traces in sea water samples

    International Nuclear Information System (INIS)

    The trace amount of total mercury (Hg) and arsenic (As) in sea water samples were quantitatively determined by using the Atomic Absorption Spectrometry connected with the hydride generation technique (HG-AAS) for As, and with the cold vapour technique (CV-AAS) for Hg. The experiments were carried out at room temperature on a Hydride System Module (HS55) combined with an Atomic Absorption Spectrometer (VARIO 6, Analytik Jena AG). The effect of reductants concentration, and that of matrix on the absorption intensity of each analyzed element was studied in details. The sea water sample after fitrating through a membrane with 0.45(μm-hole size was pre-treated with an oxidant or an reductant to obtain the identical medium. The absorption intensity of each element was then measured on the VARIO-6 under the optimum parameters for spectrometer such as: maximum wavelength, current of hollow cathode lamp, and that for hydride system such as cell temperature, speed of peristaltic pump, pump time, reaction time and rewash time, ect. The analytical procedures were set-up and applied for the determination of these above mentioned elements in the synthesized sea water sample and in the real sea water samples with high precision and accuracy. (author)

  5. Determination of trace metallic impurities in plutonium bearing mixed oxide nuclear fuel using atomic emission spectrometry

    International Nuclear Information System (INIS)

    Presently AFFF is engaged in fabrication of PFBR MOX fuel with nominal composition of (U0.79Pu0.21)O2 and (U0.72Pu0.28)O2. Chemical characterization of these fuels for trace metallic impurities is one of the pre-requisite for their use inside the reactor as trace metallic elements influence the fuel integrity and neutron economy significantly. B, Cd, Dy, Eu, Gd and Sm have large neutron absorption cross-section; their presence results in loss of neutrons. Refractory elements such as W, Mo, Ta etc. cause creep resistance resulting in clad damage. Low melting elements such as Zn may cause liquid metal embrittlement altering the fuel structure and consequently failure. Presence of alkali and alkaline earth changes the density and reduces the fissile content. Fe, Cr, Ni, Cu and Pb are the indicators for the process pickup and condition (wear/tear) of process equipment. Overall high impurity content leads to fuel dilution and deterioration of chemical and metallurgical properties of fuel

  6. Determination of Trace Iron in High Purity Sodium Fluoride by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensi tivity of iron increased in 1.27 fold by the addition of nickel nitrate. The method is applied to the determina tion of iron in sodium fluoride and satisfactory results are obtained.

  7. Pre-concentration of trace metals from sea-water for determination by graphite-furnace atomic-absorption spectrometry.

    Science.gov (United States)

    Sturgeon, R E; Berman, S S; Desaulniers, A; Russell, D S

    1980-02-01

    Determination of Cd, Zn, Pb, Cu, Fe, Mn, Co, Cr and Ni in coastal sea-water by graphite-furnace atomic-absorption spectrometry after preconcentration by solvent extraction and use of a chelating ion-exchange resin is described. Following the extraction of the pyrrolidine-N-carbodithioate and oxinate complexes into methyl isobutyl ketone, the trace metals are further preconcentrated by back-extraction into 1.5M nitric acid. Preconcentration on the chelating resin is effected by a combined column and batch technique, allowing greater preconcentration factors to be obtained. Provided samples are appropriately treated to release non-labile metal species prior to preconcentration, both methods yield comparable analytical results with respect to the mean concentrations determined as well as to mean relative standard deviations. Control and treatment of the analytical blank is also described. PMID:18962623

  8. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hagarová, Ingrid, E-mail: hagarova@fns.uniba.sk; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb–dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 μl of methanol acidified with 0.2 mol l{sup −1} HNO{sub 3}. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 μg l{sup −1}, quantification limit of 0.38 μg l{sup −1}, relative standard deviation of 4.2% (for 2 μg l{sup −1} of Pb; n = 26), linearity of the calibration graph in the range of 0.5–4.0 μg l{sup −1} (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91–96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters. - Highlights: • The potential of coacervates for the extraction of metal ions is examined. • No difficulties in coupling of ETAAS with the proposed CAE are observed. • Achieved preconcentration factor results in enhanced sensitivity. • Analytical performance is confirmed by the reliable determination of trace Pb. • The proposed CAE is ecofriendly and efficient.

  9. Determination of ultra trace arsenic species in water samples by hydride generation atomic absorption spectrometry after cloud point extraction

    Energy Technology Data Exchange (ETDEWEB)

    Ulusoy, Halil Ibrahim, E-mail: hiulusoy@yahoo.com [University of Cumhuriyet, Faculty of Science, Department of Chemistry, TR-58140, Sivas (Turkey); Akcay, Mehmet; Ulusoy, Songuel; Guerkan, Ramazan [University of Cumhuriyet, Faculty of Science, Department of Chemistry, TR-58140, Sivas (Turkey)

    2011-10-10

    Graphical abstract: The possible complex formation mechanism for ultra-trace As determination. Highlights: {yields} CPE/HGAAS system for arsenic determination and speciation in real samples has been applied first time until now. {yields} The proposed method has the lowest detection limit when compared with those of similar CPE studies present in literature. {yields} The linear range of the method is highly wide and suitable for its application to real samples. - Abstract: Cloud point extraction (CPE) methodology has successfully been employed for the preconcentration of ultra-trace arsenic species in aqueous samples prior to hydride generation atomic absorption spectrometry (HGAAS). As(III) has formed an ion-pairing complex with Pyronine B in presence of sodium dodecyl sulfate (SDS) at pH 10.0 and extracted into the non-ionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114). After phase separation, the surfactant-rich phase was diluted with 2 mL of 1 M HCl and 0.5 mL of 3.0% (w/v) Antifoam A. Under the optimized conditions, a preconcentration factor of 60 and a detection limit of 0.008 {mu}g L{sup -1} with a correlation coefficient of 0.9918 was obtained with a calibration curve in the range of 0.03-4.00 {mu}g L{sup -1}. The proposed preconcentration procedure was successfully applied to the determination of As(III) ions in certified standard water samples (TMDA-53.3 and NIST 1643e, a low level fortified standard for trace elements) and some real samples including natural drinking water and tap water samples.

  10. Cloud point extraction for trace inorganic arsenic speciation analysis in water samples by hydride generation atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shan, E-mail: ls_tuzi@163.com; Wang, Mei, E-mail: wmei02@163.com; Zhong, Yizhou, E-mail: yizhz@21cn.com; Zhang, Zehua, E-mail: kazuki.0101@aliyun.com; Yang, Bingyi, E-mail: e_yby@163.com

    2015-09-01

    A new cloud point extraction technique was established and used for the determination of trace inorganic arsenic species in water samples combined with hydride generation atomic fluorescence spectrometry (HGAFS). As(III) and As(V) were complexed with ammonium pyrrolidinedithiocarbamate and molybdate, respectively. The complexes were quantitatively extracted with the non-ionic surfactant (Triton X-114) by centrifugation. After addition of antifoam, the surfactant-rich phase containing As(III) was diluted with 5% HCl for HGAFS determination. For As(V) determination, 50% HCl was added to the surfactant-rich phase, and the mixture was placed in an ultrasonic bath at 70 °C for 30 min. As(V) was reduced to As(III) with thiourea–ascorbic acid solution, followed by HGAFS. Under the optimum conditions, limits of detection of 0.009 and 0.012 μg/L were obtained for As(III) and As(V), respectively. Concentration factors of 9.3 and 7.9, respectively, were obtained for a 50 mL sample. The precisions were 2.1% for As(III) and 2.3% for As(V). The proposed method was successfully used for the determination of trace As(III) and As(V) in water samples, with satisfactory recoveries. - Highlights: • Cloud point extraction was firstly established to determine trace inorganic arsenic(As) species combining with HGAFS. • Separate As(III) and As(V) determinations improve the accuracy. • Ultrasonic release of complexed As(V) enables complete As(V) reduction to As(III). • Direct HGAFS analysis can be performed.

  11. Cloud point extraction for trace inorganic arsenic speciation analysis in water samples by hydride generation atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    A new cloud point extraction technique was established and used for the determination of trace inorganic arsenic species in water samples combined with hydride generation atomic fluorescence spectrometry (HGAFS). As(III) and As(V) were complexed with ammonium pyrrolidinedithiocarbamate and molybdate, respectively. The complexes were quantitatively extracted with the non-ionic surfactant (Triton X-114) by centrifugation. After addition of antifoam, the surfactant-rich phase containing As(III) was diluted with 5% HCl for HGAFS determination. For As(V) determination, 50% HCl was added to the surfactant-rich phase, and the mixture was placed in an ultrasonic bath at 70 °C for 30 min. As(V) was reduced to As(III) with thiourea–ascorbic acid solution, followed by HGAFS. Under the optimum conditions, limits of detection of 0.009 and 0.012 μg/L were obtained for As(III) and As(V), respectively. Concentration factors of 9.3 and 7.9, respectively, were obtained for a 50 mL sample. The precisions were 2.1% for As(III) and 2.3% for As(V). The proposed method was successfully used for the determination of trace As(III) and As(V) in water samples, with satisfactory recoveries. - Highlights: • Cloud point extraction was firstly established to determine trace inorganic arsenic(As) species combining with HGAFS. • Separate As(III) and As(V) determinations improve the accuracy. • Ultrasonic release of complexed As(V) enables complete As(V) reduction to As(III). • Direct HGAFS analysis can be performed

  12. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL-1. The relative standard deviation (n = 7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin.

  13. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun Mei, E-mail: sunmei@ustc.edu.cn [Hefei National Laboratory for Physical Sciences on Microscale, University of Science and Technology of China, No. 96, Jinzhai Road, Hefei 230026 (China); Wu Qianghua [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026 (China)

    2010-04-15

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL{sup -1}. The relative standard deviation (n = 7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin.

  14. Cloud point extraction for trace inorganic arsenic speciation analysis in water samples by hydride generation atomic fluorescence spectrometry

    Science.gov (United States)

    Li, Shan; Wang, Mei; Zhong, Yizhou; Zhang, Zehua; Yang, Bingyi

    2015-09-01

    A new cloud point extraction technique was established and used for the determination of trace inorganic arsenic species in water samples combined with hydride generation atomic fluorescence spectrometry (HGAFS). As(III) and As(V) were complexed with ammonium pyrrolidinedithiocarbamate and molybdate, respectively. The complexes were quantitatively extracted with the non-ionic surfactant (Triton X-114) by centrifugation. After addition of antifoam, the surfactant-rich phase containing As(III) was diluted with 5% HCl for HGAFS determination. For As(V) determination, 50% HCl was added to the surfactant-rich phase, and the mixture was placed in an ultrasonic bath at 70 °C for 30 min. As(V) was reduced to As(III) with thiourea-ascorbic acid solution, followed by HGAFS. Under the optimum conditions, limits of detection of 0.009 and 0.012 μg/L were obtained for As(III) and As(V), respectively. Concentration factors of 9.3 and 7.9, respectively, were obtained for a 50 mL sample. The precisions were 2.1% for As(III) and 2.3% for As(V). The proposed method was successfully used for the determination of trace As(III) and As(V) in water samples, with satisfactory recoveries.

  15. Determination of trace nickel in water samples by cloud point extraction preconcentration coupled with graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun Zhimei [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Department of Chemistry and Biology, Huainan Normal University, Huainan 232001 (China); Liang Pei [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)]. E-mail: liangpei@mail.ccnu.edu.cn; Ding Qiong [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Cao Jing [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)

    2006-09-21

    A new method based on the cloud point extraction (CPE) preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the determination of trace nickel in water samples. When the micelle solution temperature is higher than the cloud point of surfactant p-octylpolyethyleneglycolphenyether (Triton X-100), the complex of Ni{sup 2+} with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) could enter surfactant-rich phase and be concentrated, then determined by GFAAS. The main factors affecting the cloud point extraction were investigated in detail. An enrichment factor of 27 was obtained for the preconcentration of Ni{sup 2+} with 10 mL solution. Under the optimal conditions, the detection limit of Ni{sup 2+} is 0.12 ng mL{sup -1} with R.S.D. of 4.3% (n = 10, c = 100 ng mL{sup -1}). The proposed method was applied to determination of trace nickel in water samples with satisfactory results.

  16. Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, B.R.

    1979-05-25

    Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

  17. Intense source of cold cesium atoms based on a two-dimensional magneto–optical trap with independent axial cooling and pushing

    Science.gov (United States)

    Jia-Qiang, Huang; Xue-Shu, Yan; Chen-Fei, Wu; Jian-Wei, Zhang; Li-Jun, Wang

    2016-06-01

    We report our studies on an intense source of cold cesium atoms based on a two-dimensional (2D) magneto–optical trap (MOT) with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a thin pushing laser beam to extract a cold atomic beam. With the independent pushing beam, the atomic flux can be substantially optimized. The total atomic flux maximum obtained in the 2D-HP MOT is 4.02 × 1010 atoms/s, increased by 60 percent compared to the traditional 2D+ MOT in our experiment. Moreover, with the pushing power 10 μW and detuning 0Γ, the 2D-HP MOT can generate a rather intense atomic beam with the concomitant light shift suppressed by a factor of 20. The axial velocity distribution of the cold cesium beams centers at 6.8 m/s with an FMHW of about 2.8 m/s. The dependences of the atomic flux on the pushing power and detuning are studied in detail. The experimental results are in good agreement with the theoretical model. Project supported by the National Natural Science Foundation of China (Grant No. 11304177).

  18. Intense source of cold cesium atoms based on a two-dimensional magneto-optical trap with independent axial cooling and pushing

    CERN Document Server

    Huang, J Q; Wu, C F; Zhang, J W; Feng, Y Y; Wang, L J

    2015-01-01

    We report our studies on an intense source of cold cesium atoms based on a two-dimensional magneto-optical trap with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a thin pushing laser beam for cold atomic beam extraction. Regulated independently by the pushing beam, the atomic flux can be substantially optimized. The atomic flux maximum obtained in the 2D-HP MOT is $4.02\\times 10^{10}$ atoms/s, increased by 60 percent compared to the traditional 2D$^+$ MOT in our experiment. Moreover, with the pushing power 10 $\\mu$W and detuning $0\\Gamma$, the 2D-HP MOT can generate a rather intense cold cesium atomic beam with the concomitant light shift suppressed by 20 times in magnitude. The axial velocity distribution of the cold cesium beams centers at 6.8 m/s with a FMHW of about 2.8 m/s. The dependences of the atomic flux on the pushing power and detuning are studied. The experimental results are in good agreement with the theoreti...

  19. Ambient-Temperature Trap/Release of Arsenic by Dielectric Barrier Discharge and Its Application to Ultratrace Arsenic Determination in Surface Water Followed by Atomic Fluorescence Spectrometry.

    Science.gov (United States)

    Mao, Xuefei; Qi, Yuehan; Huang, Junwei; Liu, Jixin; Chen, Guoying; Na, Xing; Wang, Min; Qian, Yongzhong

    2016-04-01

    A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge. PMID:26976077

  20. The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duyck, Christiane; Miekeley, Norbert; Porto da Silveira, Carmem L.; Aucelio, Ricardo Q. [Departamento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil); Campos, Reinaldo C. [Departamento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil)], E-mail: rccampos@rdc.puc-rio.br; Grinberg, Patricia; Brandao, Geisamanda P. [Departamento de Quimica da Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro (Brazil)

    2007-09-15

    A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions are examined as well as their implications in terms of reservoir geochemistry, oil refining and environment. The particular analytical challenges for the determination of metals in these complex matrices by spectrochemical techniques are discussed. Sample preparation based on ashing, microwave-assisted digestion and combustion decomposition procedures is noted as robust and long used. However, the introduction of non-aqueous solvents and micro-emulsions into inductively coupled plasmas is cited as a new trend for achieving rapid and accurate analysis. Separation procedures for operationally defined fractions in crude oil are more systematically applied for the observation of metal distributions and their implications. Chemical speciation is of growing interest, achieved by the coupling of high efficiency separation techniques (e.g., HPLC and GC) to ICP-MS instrumentation, which allows the simultaneous determination of multiple organometallic species of geochemical and environmental importance.

  1. Tracing the Milky Way Nuclear Wind with 21cm Atomic Hydrogen Emission

    CERN Document Server

    Lockman, Felix J

    2016-01-01

    There is evidence in 21cm HI emission for voids several kpc in size centered approximately on the Galactic centre, both above and below the Galactic plane. These appear to map the boundaries of the Galactic nuclear wind. An analysis of HI at the tangent points, where the distance to the gas can be estimated with reasonable accuracy, shows a sharp transition at Galactic radii $R\\lesssim 2.4$ kpc from the extended neutral gas layer characteristic of much of the Galactic disk, to a thin Gaussian layer with FWHM $\\sim 125$ pc. An anti-correlation between HI and $\\gamma$-ray emission at latitudes $10^{\\circ} \\leq |b| \\leq 20^{\\circ}$ suggests that the boundary of the extended HI layer marks the walls of the Fermi Bubbles. With HI we are able to trace the edges of the voids from $|z| > 2$ kpc down to $z\\approx0$, where they have a radius $\\sim 2$ kpc. The extended HI layer likely results from star formation in the disk, which is limited largely to $R \\gtrsim 3$ kpc, so the wind may be expanding into an area of rela...

  2. The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry

    Science.gov (United States)

    Duyck, Christiane; Miekeley, Norbert; Porto da Silveira, Carmem L.; Aucélio, Ricardo Q.; Campos, Reinaldo C.; Grinberg, Patrícia; Brandão, Geisamanda P.

    2007-09-01

    A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions are examined as well as their implications in terms of reservoir geochemistry, oil refining and environment. The particular analytical challenges for the determination of metals in these complex matrices by spectrochemical techniques are discussed. Sample preparation based on ashing, microwave-assisted digestion and combustion decomposition procedures is noted as robust and long used. However, the introduction of non-aqueous solvents and micro-emulsions into inductively coupled plasmas is cited as a new trend for achieving rapid and accurate analysis. Separation procedures for operationally defined fractions in crude oil are more systematically applied for the observation of metal distributions and their implications. Chemical speciation is of growing interest, achieved by the coupling of high efficiency separation techniques (e.g., HPLC and GC) to ICP-MS instrumentation, which allows the simultaneous determination of multiple organometallic species of geochemical and environmental importance.

  3. Determination of Trace Selenium in Electrolytic Manganese by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    YAO Jun; ZHOU Fang-qin; MA Cheng-jin; TUO Yong; LIU Jian-ben; WU Zhu-qin; TAN Zhu-zhong

    2003-01-01

    The effects of four types of graphite tube and five matrix modifiers on the determination of selenium by graphite furnace atomic absorption spectrometry were compared.The results show that platform thermolysis coat graphite tube and magnesium nitrate and cobaltco as matrix modifer can get a high sensitivity and a good recovery.The optimized working conditions and interference in the determination were invesigated.This result is consistent with that of XRF.The recovery is from 100.8 % to102.2 %,the relative standard deviation is from 3.47% to 5.56 % (n=9),and the detection limit of selenium is 378 pg (C=44.5μg/g to 97.3μg/g.).The proposed method can be applied to the rapid determination of selenium in electrolytic manganese.

  4. Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

    International Nuclear Information System (INIS)

    Highlights: • Analysis of estrogens in small volume samples at low parts-per-trillion concentration. • Charged bulk derivatization facilitates on-line ion exchange sample preparation. • On-line WCX restricted access media traps analytes, but not proteins and lipids. • Complete preparation and LC–MS/MS analysis completed in 30 min/sample. - Abstract: Estrone (E1), estradiols (α/β-E2), and estriol (E3) are four major metabolically active estrogens exerting strong biological activities at very low circulating concentrations. This paper reports a sensitive and efficient method with automated, on-line clean-up and detection to determine trace estrogens in a small volume of serum samples using liquid chromatography–electrospray ionization–tandem mass spectrometry directly, without off-line liquid–liquid or solid-phase extraction pretreatments. Serum aliquots (charcoal stripped fetal bovine serum, 100 μL) were spiked with four estrogen standards and their corresponding isotope-labeled internal standards, then bulk derivatized with 2-fluoro-1-methyl-pyridium p-toluenesulfonate (2-FMP) to establish the calibration curves and perform method validation. Calibration was established in the concentration ranges of 5–1000 pg mL−1, and demonstrated good linearity of R2 from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL−1. Good accuracy and precision in the range of 86–112% and 2.3–11.9%, respectively, were observed for the quality control (QC) samples at low, medium, and high concentration levels. The stability tests showed that the derivatized serum samples were stable 8 h after derivatization at room temperature and at least to 48 h if stored at −20 °C. The method was applied to measure trace estrogens in real human and bovine serum samples, and three of four estrogen compounds studied were observed and quantified

  5. Economical Alternatives for High Sensitivity in Atomic Spectrometry Laboratory

    Directory of Open Access Journals (Sweden)

    O. Yavuz Ataman

    2007-12-01

    Full Text Available The most commonly used analytical tools for determination of elements at trace levels are atomic absorption spectrometry (AAS, inductively coupled plasma, optical emission and mass spectrometry (ICP-OES and ICP-MS and atomic fluorescence spectrometry (AFS. Although sensitive plasma techniques are becoming predominant in most of the western laboratories, AAS keeps its importance in developing countries. Simple and inexpensive ways of enhancing sensitivity will be described for laboratories equipped with only a flame AA spectrometer. Although there are many chemical preconcentration procedures to improve sensitivity of flame AAS, only some atom trapping techniques will be included here. One kind of atom trapping device is a slotted quartz tube (SQT used for in situ preconcentration of analyte species followed by a rapid revolatilization cycle to obtain an enhanced signal. These devices provide limits of detection at a level of µg L-1. Another kind of atom trapping involves use of vapor generation technique and quartz or tungsten atom trapping surfaces. The analytical steps consist of the generation of volatile species, usually by hydride formation using NaBH4, trapping these species at the surface of an atom trap held at an optimized temperature and finally re-volatilizing analyte species by rapid heating of trap. These species are transported using a carrier gas to an externally heated quartz tube as commonly used in hydride generation AAS systems; a transient signal is formed and measured. These traps have limits of detection in the order of ng L-1.

  6. USEPA METHOD STUDY 38 - SW-846 METHOD 3010, ACID DIGESTION OF AQUEOUS SAMPLES AND EXTRACTS FOR TRACE METALS BY FLAME ATOMIC ABSORPTION SPECTROSCOPY

    Science.gov (United States)

    An interlaboratory collaborative study was conducted on SW-846 Method 3010, "Acid Digestion of Aqueous Samples and Extracts for Total Metals for Analysis by Flame Atomic Absorption Spectroscopy", to determine the mean recovery and precision for analyses of 21 trace metals in surf...

  7. Determination of trace selenium in high purity tellurium by hydride generation atomic fluorescence spectrometry after solid phase extraction of a diaminobenzidine-selenium chelate

    Science.gov (United States)

    Tong, Wang; Ying, Zeng; Jinyong, Xu

    2016-09-01

    Macroporous adsorption resin was used as the sorbent for solid phase extraction and determination of the trace Se content in high purity tellurium prior to hydride generation atomic fluorescence spectrometry analysis. Selenium was converted into an organic Se chelate using 3,3‧-diaminobenzidine and was separated from the tellurium matrix by solid phase extraction. The resin was packed as a column for solid phase extraction. Under optimum conditions, trace Se can be quantitatively extracted and the tellurium matrix can be removed. The Se in the eluate was determined by hydride generation atomic fluorescence spectrometry. The limit of detection (3σ) of this method was 0.22 ng g- 1 and the relative standard deviation (RSD, n = 5) ranged from 2.0 to 2.5% for the three investigated tellurium samples. The proposed method was successfully applied for the determination of the trace Se content in high purity tellurium samples.

  8. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  9. Separation of trace antimony and arsenic prior to hydride generation atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    A separation method utilizing a synthetic zeolite (mordenite) was developed in order to eliminate the gas phase interference of Sb(III) on As(III) during quartz furnace hydride generation atomic absorption spectrometric (HGAAS) determination. The efficiency of the proposed separation method in the reduction of suppression effects of transition metal ions on As(III) signal was also investigated. Among the volatile hydride-forming elements and their different oxidation states tested (Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), and Te(VI)), only Sb(III) was found to have a signal depression effect even at low (μg l-1) concentrations under the experimental conditions employed. It has been shown that mordenite adsorbs Sb(III) quantitatively, even at a concentration of 1000 μg l-1, at pHs greater than two, and also, it reduces the initial concentrations of the transition metal ions to lower levels which can be tolerated in many studies. The adsorption of Sb(III) on mordenite follows the Freundlich isotherm and is endothermic in nature

  10. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    Science.gov (United States)

    Ball, J.W.; Nordstrom, D.K.

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of

  11. Two-stage magneto-optical trapping and narrow-line cooling of $^6$Li atoms to high phase-space density

    CERN Document Server

    Sebastian, Jimmy; Li, Ke; Gan, Huat Chai Jaren; Li, Wenhui; Dieckmann, Kai

    2014-01-01

    We report an experimental study of peak and phase-space density of a two-stage magneto-optical trap (MOT) of 6-Li atoms, which exploits the narrower $2S_{1/2}\\rightarrow 3P_{3/2}$ ultra-violet (UV) transition at 323 nm following trapping and cooling on the more common D2 transition at 671 nm. The UV MOT is loaded from a red MOT and is compressed to give a high phase-space density up to $3\\times 10^{-4}$. Temperatures as low as 33 $\\mu$K are achieved on the UV transition. We study the density limiting factors and in particular find a value for the light-assisted collisional loss coefficient of $1.3 \\pm0.4\\times10^{-10}\\,\\textrm{cm}^3/\\textrm{s}$ for low repumping intensity.

  12. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Hagarová, Ingrid; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb-dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 μl of methanol acidified with 0.2 mol l- 1 HNO3. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 μg l- 1, quantification limit of 0.38 μg l- 1, relative standard deviation of 4.2% (for 2 μg l- 1 of Pb; n = 26), linearity of the calibration graph in the range of 0.5-4.0 μg l- 1 (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91-96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters.

  13. Immersed single-drop microextraction-electrothermal vaporization atomic absorption spectroscopy for the trace determination of mercury in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu [Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of); Naderi, Mehrnoush [Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2009-06-15

    A new method based on single-drop microextraction (SDME) combined with electrothermal vaporization atomic absorption spectroscopy (ETV-AAS) was developed for the trace determination of mercury in water samples. A microdrop of m-xylene was applied as the extraction solvent. After extraction, the microdrop was introduced, directly, into a graphite furnace of AAS. Some important extraction parameters such as type of solvent, volume of solvent, sample stirring, ionic strength, sample pH, chelating agent concentration, sample temperature, and extraction time were investigated and optimized. The highest possible microdrop volume of 10 {mu}L, a sampling temperature of 27 {sup o}C, and use of m-xylene containing dithizone, as complexing agent, are major parameters led to achieve a high enrichment factor of 970. Under the optimized conditions, the detection limit of the method was 0.01 {mu}g L{sup -1} and the relative standard deviation was 6.1% (n = 7). The proposed method has been successfully applied to the determination of Hg in two river water samples. The effects of interfering species such as Pt, Pd, Cu, Au, and Bi, having the tendency to form complexes with dithizone, at two concentration levels of 100 and 1000 {mu}g L{sup -1} were also studied.

  14. Cloud point extraction-flame atomic absorption spectrometry method for preconcentration and determination of trace cadmium in water samples.

    Science.gov (United States)

    Ning, Jinyan; Jiao, Yang; Zhao, Jiao; Meng, Lifen; Yang, Yaling

    2014-01-01

    A method based on cloud point extraction (CPE) separation/preconcentration of trace cadmium (Cd) as a prior step to its determination by flame atomic absorption spectrometry has been developed. Cadmium reacted with 8-hydroxyquinoline to form hydrophobic chelates, which were extracted into the micelles of nonionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) in an alkaline medium. Octanol was used to depress the cloud point of Genapol X-080 in the extraction process. The chemical variables that affect the CPE, such as pH of complexation reaction, amount of chelating agent, Genapol X-080 and octanol were evaluated and optimized. Under optimized conditions, linearity was obeyed in the range of 10-500 μg/L, with the correlation coefficient of 0.9993. For 5 mL of sample solution, the enhancement factor was about 20. The limit of detection and limit of quantification of the method were 0.21 and 0.63 μg/L, respectively. The relative standard deviations (n = 6) was 3.2% for a solution containing 100 μg/L of Cd. The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. Recoveries of spiked samples varied in the range of 94.1-103.8%.

  15. Evaluation of various techniques for the pretreatment of sewage sludges prior to trace metal analysis by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Six techniques were evaluated for their suitability for the pretreatment of dried sewage sludge prior to trace metal analysis by atomic absorption spectrophotometry. The evaluation comprised analysis of two prepared samples of dried sludge for aluminium, cadmium, chromium, copper, iron, lead, manganese, nickel and zinc, after the following pretreatment: dry ashing at 500 degrees Celsius followed by extraction with dilute hydrochloric acid; dry ashing at 500 degrees Celsius followed by extraction with aqua regia; nitric acid digestion followed by extraction with hydrochloric acid; extraction with aqua regia; ashing with magnesium nitrate solution at 550 degrees Celsius followed by digestion with hydrochloric acid and extraction with nitric acid; extraction with nitric acid. Procedures involving the use of perchloric acid, hydrofluoric acid and hydrogen peroxide were not considered for reasons of safety. Except in the case of aluminium the direct mineral acid digestion and/or extraction methods generally gave higher recoveries than the procedures incorporating an ashing step. Direct extraction of the sample with aqua regia was recommended as a rapid and simple general method of sample pretreatment prior to analysis for all the metals investigated except aluminium. For this metal, more drastic sample pretreatment will be required, for example fusion or hydrofluoric acid digestion

  16. Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

    Energy Technology Data Exchange (ETDEWEB)

    Beinhauer, Jana [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Bian, Liangqiao [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Fan, Hui [Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); Šebela, Marek [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Kukula, Maciej [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Barrera, Jose A. [Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); and others

    2015-02-09

    Highlights: • Analysis of estrogens in small volume samples at low parts-per-trillion concentration. • Charged bulk derivatization facilitates on-line ion exchange sample preparation. • On-line WCX restricted access media traps analytes, but not proteins and lipids. • Complete preparation and LC–MS/MS analysis completed in 30 min/sample. - Abstract: Estrone (E1), estradiols (α/β-E2), and estriol (E3) are four major metabolically active estrogens exerting strong biological activities at very low circulating concentrations. This paper reports a sensitive and efficient method with automated, on-line clean-up and detection to determine trace estrogens in a small volume of serum samples using liquid chromatography–electrospray ionization–tandem mass spectrometry directly, without off-line liquid–liquid or solid-phase extraction pretreatments. Serum aliquots (charcoal stripped fetal bovine serum, 100 μL) were spiked with four estrogen standards and their corresponding isotope-labeled internal standards, then bulk derivatized with 2-fluoro-1-methyl-pyridium p-toluenesulfonate (2-FMP) to establish the calibration curves and perform method validation. Calibration was established in the concentration ranges of 5–1000 pg mL{sup −1}, and demonstrated good linearity of R{sup 2} from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL{sup −1}. Good accuracy and precision in the range of 86–112% and 2.3–11.9%, respectively, were observed for the quality control (QC) samples at low, medium, and high concentration levels. The stability tests showed that the derivatized serum samples were stable 8 h after derivatization at room temperature and at least to 48 h if stored at −20 °C. The method was applied to measure trace estrogens in real human and bovine serum samples, and three of four estrogen compounds studied were observed and quantified.

  17. Collisional properties of cold spin-polarized nitrogen gas: theory, experiment, and prospects as a sympathetic coolant for trapped atoms and molecules

    CERN Document Server

    Tscherbul, T V; Dalgarno, A; Zygelman, B; Pavlovic, Z; Hummon, M T; Lu, H-I; Tsikata, E; Doyle, J M

    2010-01-01

    We report a combined experimental and theoretical study of collision-induced dipolar relaxation in a cold spin-polarized gas of atomic nitrogen (N). We use buffer gas cooling to create trapped samples of 14N and 15N atoms with densities 5+/-2 x 10^{12} cm-3 and measure their magnetic relaxation rates at milli-Kelvin temperatures. Rigorous quantum scattering calculations based on accurate ab initio interaction potentials for the 7Sigma_u electronic state of N2 demonstrate that dipolar relaxation in N + N collisions occurs at a slow rate of ~10^{-13} cm3/s over a wide range of temperatures (1 mK to 1 K) and magnetic fields (10 mT to 2 T). The calculated dipolar relaxation rates are insensitive to small variations of the interaction potential and to the magnitude of the spin-exchange interaction, enabling the accurate calibration of the measured N atom density. We find consistency between the calculated and experimentally determined rates. Our results suggest that N atoms are promising candidates for future expe...

  18. Bright solitons and self-trapping with a BEC of cold atoms in driven tilted optical lattices

    OpenAIRE

    Kolovsky, Andrey R.

    2010-01-01

    We suggest a method for creating bright matter solitons by loading a BEC of atoms in a driven tilted optical lattice. It is shown that one can realize the self-focussing regime for the wave-packet dynamics by properly adjusting the phase of the driving field with respect to the phase of Bloch oscillations. If atom-atom interactions are larger than some critical value $g_{min}$, this self-focussing regime is followed by the formation of bright solitons. Increasing the interactions above anothe...

  19. Trace-element determination in lichens of Cordoba (Argentina) using neutron activation analysis and atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ramalina ecklonii (Spreng.) Mey. and Flot. is a lichen widely distributed in Cordoba, a central province of Argentina. The ability of this lichen as an atmospheric pollution bioindicator has already been studied in relation to its physiological response to air pollutants. This work has to do with the study of R. ecklonii in terms of its capacity to accumulate heavy metals and other trace elements. The sampled area, located in the province of Cordoba, covered 50,000 km2 and was divided following a grid of 25 x 25 km. Lichens were collected at the intersecting points, no least than 500 m from main routes or highly populated centres and individuals were randomly gathered following the four cardinal directions and no more than 100 m from the geographically settled point. From each pool, three sub-samples were taken for independent analysis using atomic absorption spectrometry (AAS) and neutron activation analysis (NAA), for the determination of twenty nine elements (Cu, Ni, Mn, and Pb (AAS) and As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb, and Zn (NAA). The quality of the determinations was checked using standard reference material and data sets were evaluated using descriptive statistics, correlation analysis, and factor analysis. The highest variation coefficients correspond to Ca, Cr, and Zn. The studied elements were identified as of physiological importance and as emitted by natural (soil and rocks) and anthropogenic sources (non-ferrous metallurgy, coal combustion, oil-fired plants, fossil fuel combustion and, other industries). (author)

  20. Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

    Science.gov (United States)

    Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

    2002-05-01

    The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

  1. Selective Flow Injection Analysis of Ultra-trace Amounts of Cr(VI), Preconcentration of It by Solvent Extraction, and Determination by Electrothermal Atomic Absorption Spectrometry (ETAAS)

    DEFF Research Database (Denmark)

    Nielsen, Steffen; Sturup, Stefan; Spliid, Henrik;

    1999-01-01

    A rapid, robust, sensitive and selective time-based flow injection (FI) on-line solvent extraction system interfaced with electrothermal atomic absorption spectrometry (ETAAS) is described for analyzing ultra-trace amounts of Cr(VI). The sample is initially mixed on-line with isobutyl methyl keto......(VI)-reference material, synthetic seawater and waste waters, and waste water samples from an incineration plant and a desulphurization plant, respectively....

  2. Determination of Mecruy at Trace Level in Natural Water Samples by Hydride Generation Atomic Absorption Spectrophotometry after Cloud Point Extraction Preconcentration

    Institute of Scientific and Technical Information of China (English)

    Ji Ying SONG; Ming HOU; Li Xiang ZHANG

    2006-01-01

    A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work.The effects of pH, concentration of surfactant, and equilibration time on cloud point extraction were discussed. The enhancement factor of 20 and the detection limit of 0.039 μg/L were obtained for mercury with relative standard deviation of 4.8% (n = 11).

  3. Trace enrichment with activated carbon and determination of Ni, Hg, Sn and Cd using diethyldithiocarbamate as complexant by atomic emission spectrography (AES)

    International Nuclear Information System (INIS)

    A methods has been developed for the preconcentration and determination of trace amounts of Hg, Ni, Sn and Cd in aqueous solutions. The complexes of these elements with sodium diethyl dithiocarbamate were adsorbed on activated charcoal and determined by atomic emission spectrography d-c arc technique. Factors which affect the quantitative recovery of the microamounts of the elements were optimised. Pd was used as an internal standard. The detection limits ranged from 0.01 to 0.05 ppm. (author)

  4. Atom Chips

    CERN Document Server

    Folman, R; Cassettari, D; Hessmo, B; Maier, T; Schmiedmayer, J; Folman, Ron; Krüger, Peter; Cassettari, Donatella; Hessmo, Björn; Maier, Thomas

    1999-01-01

    Atoms can be trapped and guided using nano-fabricated wires on surfaces, achieving the scales required by quantum information proposals. These Atom Chips form the basis for robust and widespread applications of cold atoms ranging from atom optics to fundamental questions in mesoscopic physics, and possibly quantum information systems.

  5. A HBAR-oscillator-based 4.596~GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    CERN Document Server

    Daugey, Thomas; Martin, Gilles; Boudot, Rodolphe

    2015-01-01

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596~GHz frequency source. A 2.298~GHz signal, generated by an oscillator constructed around a thermally-controlled two-port AlN-sapphire HBAR resonator with a Q-factor of 24000 at 68$^{\\circ}$C, is frequency multiplied by 2 to 4.596~GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency (TCF) of the HBAR is measured to be $-23$~ppm/$^{\\circ}$C at 2.298~GHz. The measured phase noise of the 4.596~GHz source is $-105$~dBrad$^2$/Hz at 1~kHz offset and $-150$~dBrad$^2$/Hz at 100~kHz offset. The 4.596~GHz output signal is used as a local oscillator (LO) in a laboratory-prototype Cs microcell-based coherent population trapping (CPT) atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter (VCPS) implemented in the 2.298~GHz HBAR-oscillator loop, preventing the need for a high-power-consuming...

  6. Source and mode of the Permian Panjal Trap magmatism: Evidence from zircon U-Pb and Hf isotopes and trace element data from the Himalayan ultrahigh-pressure rocks

    Science.gov (United States)

    Rehman, Hafiz Ur; Lee, Hao-Yang; Chung, Sun-Lin; Khan, Tahseenullah; O'Brien, Patrick J.; Yamamoto, Hiroshi

    2016-09-01

    We present an integrated study of LA-ICP-MS U-Pb age, Hf isotopes, and trace element geochemistry of zircons from the Himalayan eclogites (mafic rocks) and their host gneisses (felsic rocks) from the Kaghan Valley in Pakistan in order to understand the source and mode of their magmatic protoliths and the effect of metamorphism. Zircons from the so-called Group I (high-pressure) eclogites yielded U-Pb mean ages of 259 ± 10 Ma (MSWD = 0.74), whereas those of Group II (ultrahigh-pressure) eclogites yielded 48 ± 3 Ma (MSWD = 0.71). In felsic gneisses the central or core domains of zircons yielded ages similar to those from Group I eclogites but zircon overgrowth domains yielded 47 ± 1 Ma (MSWD = 1.9). Trace element data suggest a magmatic origin for Group I-derived (having Th/U ratios: > 0.5) and metamorphic origin for Group II-derived (Th/U rocks (Panjal Traps) with almost no contribution from the ancient crustal material. The similar ƐHf(t) values, identical protolith ages and trace element compositions of zircons in felsic (granites or rhyolites) and mafic (basalt and dolerite) rocks attest to a bimodal magmatism accounting for the Panjal Traps during the Permian. Later, during India-Asia collision in Eocene times, both the felsic and mafic lithologies were subducted to mantle-depths (> 90 km: coesite-stable) and experienced ultrahigh-pressure metamorphism before their final exhumation.

  7. Retraction notice to "Measurements of total absolute collision cross section of ultracold Rb atom using magneto-optic and pure magnetic traps" [Chinese Optics Letters 9, 060201 (2011)

    Institute of Scientific and Technical Information of China (English)

    Jicheng Wang; Yueyuan Wang; Yueke Wang; Guangyu Fang; Shutian Liu

    2011-01-01

    This article "Measurements of total absolute collision cross section of ultracold Rb atom using magneto-optic and pure magnetic traps",which was published on Chinese Optics Letters (9,060201 (2011)) has been retracted at the request of the authors.Reason:The first author,Jicheng Wang,participated in a related research in Professor Kirk Madison's group in the Department of Physics & Astronomy at the University of British Columbia,Canada from September 2008 to February 2010.Some of the experimental data have not been authorized for publication,even though they have been consented to be used by Jicheng Wang in his own research.The authors apologize to Professor K.Madison for misunderstanding,and to Chinese Optics Letters and the readers of Chinese Optics Letters for any inconvenience this mistake may have caused.

  8. Guest Editor’s Notes on the “Atoms” Special Issue on “Perspectives of Atomic Physics with Trapped Highly Charged Ions”

    Directory of Open Access Journals (Sweden)

    Elmar Träbert

    2016-02-01

    Full Text Available The study of highly charged ions (HCI was pursued first at Uppsala (Sweden, by Edlén and Tyrén in the 1930s. Their work led to the recognition that the solar corona is populated by such ions, an insight which forced massive paradigm changes in solar physics. Plasmas aiming at controlled fusion in the laboratory, laser-produced plasmas, foil-excited swift ion beams, and electron beam ion traps have all pushed the envelope in the production of HCI. However, while there are competitive aspects in the race for higher ion charge states, the real interest lies in the very many physics topics that can be studied in these ions. Out of this rich field, the Special Issue concentrates on atomic physics studies that investigate highly charged ions produced, maintained, and/or manipulated in ion traps. There have been excellent achievements in the field in the past, and including fairly recent work, they have been described by their authors at conferences and in the appropriate journals. The present article attempts an overview over current lines of development, some of which are expanded upon in this Special Issue.

  9. Determination of trace and minor elements in alloys by atomic-absorption spectroscopy using an induction-heated graphite-well furnace as atom source-II.

    Science.gov (United States)

    Ashy, M A; Headridge, J B; Sowerbutts, A

    1974-06-01

    Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour. PMID:18961510

  10. An Improved Antihydrogen Trap

    OpenAIRE

    Kalra, Rita Rani

    2015-01-01

    The recent demonstration of trapped atomic antihydrogen for 15 to 1000 seconds is a milestone towards precise spectroscopy for tests of CPT invariance. The confinement of a total of 105±21 atoms in a quadrupole magnetic trap was made possible by several improved methods. Improved accumulation techniques give us the largest numbers of constituent particles yet: up to 10 million antiprotons and several billion positrons. A novel cooling protocol leads to 3.5 K antiprotons, the coldest ever obse...

  11. Contrast and phase-shift of a trapped atom interferometer using a thermal ensemble with internal state labelling

    CERN Document Server

    Dupont-Nivet, M; Schwartz, S

    2016-01-01

    We report a theoretical study of a double-well Ramsey interferometer using internal state labelling. We consider the use of a thermal ensemble of cold atoms rather than a Bose-Einstein condensate to minimize the effects of atomic interactions. To maintain a satisfactory level of coherence in this case, a high degree of symmetry is required between the two arms of the interferometer. Assuming that the splitting and recombination processes are adiabatic, we theoretically derive the phase-shift and the contrast of such an interferometer in the presence of gravity or an acceleration field. We also consider using a "shortcut to adiabaticity" protocol to speed up the splitting process and discuss how such a procedure affects the phase shift and contrast. We find that the two procedures lead to phase-shifts of the same form.

  12. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    International Nuclear Information System (INIS)

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 μL ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL-1, the detection limit was 0.37 ng mL-1 (3Sb/m, n = 7) and the relative standard deviation was ±1.63% (n = 7, C = 200 ng mL-1). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  13. Atomic structure of Hsp90-Cdc37-Cdk4 reveals that Hsp90 traps and stabilizes an unfolded kinase.

    Science.gov (United States)

    Verba, Kliment A; Wang, Ray Yu-Ruei; Arakawa, Akihiko; Liu, Yanxin; Shirouzu, Mikako; Yokoyama, Shigeyuki; Agard, David A

    2016-06-24

    The Hsp90 molecular chaperone and its Cdc37 cochaperone help stabilize and activate more than half of the human kinome. However, both the mechanism by which these chaperones assist their "client" kinases and the reason why some kinases are addicted to Hsp90 while closely related family members are independent are unknown. Our structural understanding of these interactions is lacking, as no full-length structures of human Hsp90, Cdc37, or either of these proteins with a kinase have been elucidated. Here we report a 3.9 angstrom cryo-electron microscopy structure of the Hsp90-Cdc37-Cdk4 kinase complex. Surprisingly, the two lobes of Cdk4 are completely separated with the β4-β5 sheet unfolded. Cdc37 mimics part of the kinase N lobe, stabilizing an open kinase conformation by wedging itself between the two lobes. Finally, Hsp90 clamps around the unfolded kinase β5 strand and interacts with exposed N- and C-lobe interfaces, protecting the kinase in a trapped unfolded state. On the basis of this structure and an extensive amount of previously collected data, we propose unifying conceptual and mechanistic models of chaperone-kinase interactions. PMID:27339980

  14. Trapping and diffusion of noble gas atoms in some off-stoichiometric ceramics studied by thermal desorption spectrometry. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Hoondert, W.H.B.

    1993-01-01

    The thesis deals with the mobility of small noble gas atoms, mainly helium, in ceramic materials with high defect concentrations. Hence, two subjects are covered: diffusion and defect physics. The experimental technique employed is Thermal Desorption Spectrometry (TDS). An introductory outline of TDS is given. The present study was initiated for various reasons. First of all, research on helium retention and mobility behavior, such as bubble nucleation and subsequent bubble migration, in potential fusion reactor wall materials (which some of the ceramics are) is of practical interest. Secondly, because the ceramic materials investigated in the present work have defect concentrations on the order of percents, and because they are binary compounds where in principle more defect types can be present than in pure materials, the defect physics is more complicated and diverse than e.g., in simple metals. Finally, high defective materials can serve as a model system for thin films produced by Ion Beam Assisted Deposition (IBAD). TDS as an analytical tool is of key importance to be able to control the IBAD process, and for the understanding of the atomic-scale phenomena involved.

  15. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    Energy Technology Data Exchange (ETDEWEB)

    Daugey, Thomas; Friedt, Jean-Michel; Martin, Gilles; Boudot, Rodolphe [FEMTO-ST, CNRS, UFC, 26 chemin de l’Epitaphe 25030 Besançon Cedex (France)

    2015-11-15

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24 000 at 68 °C, is frequency multiplied by 2–4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be −23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is −105 dB rad{sup 2}/Hz at 1 kHz offset and −150 dB rad{sup 2}/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10{sup −9} at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10{sup −11} τ{sup −1/2} up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance.

  16. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock

    International Nuclear Information System (INIS)

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24 000 at 68 °C, is frequency multiplied by 2–4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be −23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is −105 dB rad2/Hz at 1 kHz offset and −150 dB rad2/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10−9 at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10−11 τ−1/2 up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance

  17. A high-overtone bulk acoustic wave resonator-oscillator-based 4.596 GHz frequency source: Application to a coherent population trapping Cs vapor cell atomic clock.

    Science.gov (United States)

    Daugey, Thomas; Friedt, Jean-Michel; Martin, Gilles; Boudot, Rodolphe

    2015-11-01

    This article reports on the design and characterization of a high-overtone bulk acoustic wave resonator (HBAR)-oscillator-based 4.596 GHz frequency source. A 2.298 GHz signal, generated by an oscillator constructed around a thermally controlled two-port aluminum nitride-sapphire HBAR resonator with a Q-factor of 24,000 at 68 °C, is frequency multiplied by 2-4.596 GHz, half of the Cs atom clock frequency. The temperature coefficient of frequency of the HBAR is measured to be -23 ppm/ °C at 2.298 GHz. The measured phase noise of the 4.596 GHz source is -105 dB rad(2)/Hz at 1 kHz offset and -150 dB rad(2)/Hz at 100 kHz offset. The 4.596 GHz output signal is used as a local oscillator in a laboratory-prototype Cs microcell-based coherent population trapping atomic clock. The signal is stabilized onto the atomic transition frequency by tuning finely a voltage-controlled phase shifter implemented in the 2.298 GHz HBAR-oscillator loop, preventing the need for a high-power-consuming direct digital synthesis. The short-term fractional frequency stability of the free-running oscillator is 1.8 × 10(-9) at one second integration time. In locked regime, the latter is improved in a preliminary proof-of-concept experiment at the level of 6.6 × 10(-11) τ(-1/2) up to a few seconds and found to be limited by the signal-to-noise ratio of the detected CPT resonance.

  18. Novel ion imprinted magnetic mesoporous silica for selective magnetic solid phase extraction of trace Cd followed by graphite furnace atomic absorption spectrometry detection

    International Nuclear Information System (INIS)

    Determination of trace Cd in environmental, biological and food samples is of great significance to toxicological research and environmental pollution monitoring. While the direct determination of Cd in real-world samples is difficult due to its low concentration and the complex matrix. Herein, a novel Cd(II)-ion imprinted magnetic mesoporous silica (Cd(II)-II-MMS) was prepared and was employed as a selective magnetic solid-phase extraction (MSPE) material for extraction of trace Cd in real-world samples followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. Under the optimized conditions, the detection limit of the proposed method was 6.1 ng L−1 for Cd with the relative standard deviation (RSD) of 4.0% (c = 50 ng L−1, n = 7), and the enrichment factor was 50-fold. To validate the proposed method, Certified Reference Materials of GSBZ 50009–88 environmental water, ZK018-1 lyophilized human urine and NIES10-b rice flour were analyzed and the determined values were in a good agreement with the certified values. The proposed method exhibited a robust anti-interference ability due to the good selectivity of Cd(II)-II-MMS toward Cd(II). It was successfully employed for the determination of trace Cd(II) in environmental water, human urine and rice samples with recoveries of 89.3–116%, demonstrating that the proposed method has good application potential in real world samples with complex matrix. - Highlights: • Novel Cd(II)-II-MMS was prepared by surface imprinting combined with a sol–gel process. • Cd(II)-II-MMS has a high selectivity and adsorption capacity for Cd(II). • A sensitive and selective method of Cd(II)-IIMSPE-GFAAS was developed for trace cadmium analysis. • The method can be applied to determine trace Cd in various samples with complicated matrix

  19. Novel ion imprinted magnetic mesoporous silica for selective magnetic solid phase extraction of trace Cd followed by graphite furnace atomic absorption spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Bingshan; He, Man; Chen, Beibei; Hu, Bin, E-mail: binhu@whu.edu.cn

    2015-05-01

    Determination of trace Cd in environmental, biological and food samples is of great significance to toxicological research and environmental pollution monitoring. While the direct determination of Cd in real-world samples is difficult due to its low concentration and the complex matrix. Herein, a novel Cd(II)-ion imprinted magnetic mesoporous silica (Cd(II)-II-MMS) was prepared and was employed as a selective magnetic solid-phase extraction (MSPE) material for extraction of trace Cd in real-world samples followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. Under the optimized conditions, the detection limit of the proposed method was 6.1 ng L{sup −1} for Cd with the relative standard deviation (RSD) of 4.0% (c = 50 ng L{sup −1}, n = 7), and the enrichment factor was 50-fold. To validate the proposed method, Certified Reference Materials of GSBZ 50009–88 environmental water, ZK018-1 lyophilized human urine and NIES10-b rice flour were analyzed and the determined values were in a good agreement with the certified values. The proposed method exhibited a robust anti-interference ability due to the good selectivity of Cd(II)-II-MMS toward Cd(II). It was successfully employed for the determination of trace Cd(II) in environmental water, human urine and rice samples with recoveries of 89.3–116%, demonstrating that the proposed method has good application potential in real world samples with complex matrix. - Highlights: • Novel Cd(II)-II-MMS was prepared by surface imprinting combined with a sol–gel process. • Cd(II)-II-MMS has a high selectivity and adsorption capacity for Cd(II). • A sensitive and selective method of Cd(II)-IIMSPE-GFAAS was developed for trace cadmium analysis. • The method can be applied to determine trace Cd in various samples with complicated matrix.

  20. Interface Trap Density Reduction for Al2O3/GaN (0001) Interfaces by Oxidizing Surface Preparation prior to Atomic Layer Deposition.

    Science.gov (United States)

    Zhernokletov, Dmitry M; Negara, Muhammad A; Long, Rathnait D; Aloni, Shaul; Nordlund, Dennis; McIntyre, Paul C

    2015-06-17

    We correlate interfacial defect state densities with the chemical composition of the Al2O3/GaN interface in metal-oxide-semiconductor (MOS) structures using synchrotron photoelectron emission spectroscopy (PES), cathodoluminescence and high-temperature capacitance-voltage measurements. The influence of the wet chemical pretreatments involving (1) HCl+HF etching or (2) NH4OH(aq) exposure prior to atomic layer deposition (ALD) of Al2O3 were investigated on n-type GaN (0001) substrates. Prior to ALD, PES analysis of the NH4OH(aq) treated surface shows a greater Ga2O3 component compared to either HCl+HF treated or as-received surfaces. The lowest surface concentration of oxygen species is detected on the acid etched surface, whereas the NH4OH treated sample reveals the lowest carbon surface concentration. Both surface pretreatments improve electrical characteristics of MOS capacitors compared to untreated samples by reducing the Al2O3/GaN interface state density. The lowest interfacial trap density at energies in the upper band gap is detected for samples pretreated with NH4OH. These results are consistent with cathodoluminescence data indicating that the NH4OH treated samples show the strongest band edge emission compared to as-received and acid etched samples. PES results indicate that the combination of reduced carbon contamination while maintaining a Ga2O3 interfacial layer by NH4OH(aq) exposure prior to ALD results in fewer interface traps after Al2O3 deposition on the GaN substrate.

  1. Tracing Noble Gas Radionuclides in the Environment

    CERN Document Server

    Collon, P; Lu, Z T

    2004-01-01

    Trace analysis of radionuclides is an essential and versatile tool in modern science and technology. Due to their ideal geophysical and geochemical properties, long-lived noble gas radionuclides, in particular, 39Ar (t1/2 = 269 yr), 81Kr (t1/2 = 2.3x10^5 yr) and 85Kr (t1/2 = 10.8 yr), have long been recognized to have a wide range of important applications in Earth sciences. In recent years, significant progress has been made in the development of practical analytical methods, and has led to applications of these isotopes in the hydrosphere (tracing the flow of groundwater and ocean water). In this article, we introduce the applications of these isotopes and review three leading analytical methods: Low-Level Counting (LLC), Accelerator Mass Spectrometry (AMS) and Atom Trap Trace Analysis (ATTA).

  2. Method 200.12 - Determination of Trace Elements in Marine Waters by StabilizedTemperature Graphite Furnace Atomic Absorption

    Science.gov (United States)

    This method provides procedures for the determination of total recoverable elements by graphite furnace atomic absorption (GFAA) in marine waters, including estuarine, ocean and brines with salinities of up to 35 ppt.

  3. Graphene for Preconcentration of Trace Amounts of Ni in Water and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens Prior to flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Hanie Arbabi Rashid

    2014-03-01

    Full Text Available A new sensitive and simple method was developed for the preconcentration of trace amounts of Ni using 1-(2-pyridylazo-2-naphthol (PAN as chelating reagent prior to its determination by flame atomic absorption spectrometry. The proposed method is based on the uti- lization of a column packed with graphene as sorbent. Several effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 5.0–240.0 µg L-1 with a detection limit of 0.36 µg L-1. The relative standard deviation for ten replicate measurements of 20.0 and 100.0 µg L-1 of Ni were 3.45 and 3.18%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Ni. In the present study, we report the application of preconcentration techniques still continues increasingly for trace metal determinations by flame atomic absorption spectrometry (FAAS for quantification of Ni in Formalin-fixed paraffin-embedded (FFPE tissues from Liver loggerhead turtles. The proposed method was successfully applied in the analysis of four real environmental water samples. Good spiked recoveries over the range of 95.8–102.6% were obtained.

  4. Ultrasound-assisted emulsification-microextraction combined with graphite furnace atomic absorption spectrometry for the determination of trace lead in water

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hongmei; Zhang, Yu; Qiu, Bocheng; Li, Wenhua [College of Science, Nanjing Agricultural University, Nan Jing (China)

    2012-04-15

    The ultrasound-assisted emulsification-microextraction (USAEME) method was combined with graphite furnace atomic absorption spectrometry (GFAAS) for the determination of trace Pb using dithizone (H{sup 2}DZ) as chelating reagent. Some effective parameters influenced the detection and microextraction, such as ashing temperature and atomization temperature, pH, extraction solvent, sample volume, extraction time, and extraction temperature were selected and optimized. After extraction, the calibration curves for Pb was in the concentration range of 0.1-10 ng mL{sup -1}, and the linear equation was y = 0.097 x + 0.023 (R = 0.99). Under the optimized conditions, the detection limit of the method was 20 pg mL{sup -1} with an enrichment factor of 70 and the relative standards deviation (RSD) for seven determinations of 1 ng mL{sup -1} Pb was 11%. The proposed method was successfully applied to determine trace Pb in Yueya Lake water, pond water, and spiked samples. Furthermore, a certified reference material of Environment Water (GBW08607) was analyzed and the determined value was in good agreement with the certified value, which showed the accuracy, recovery, and applicability of the reported method. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Cloud Point Extraction for the Determination of Trace Amounts of Cobalt in Water and Food Samples by Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Shangzhi Wang

    2013-01-01

    Full Text Available A cloud point extraction (CPE procedure which was developed for the separation and preconcentration of trace amounts of cobalt is combined with flame atomic absorption spectrometry (FAAS to determine trace amounts of cobalt in water and food samples. The procedure is based on the formation of the hydrophobic complex between Co(II and 4-methoxy-2-sulfo-benzenediazoaminoazo-benzene (MOSDAA followed by its extraction into a Triton X-114 surfactant-rich phase. The parameters such as pH of sample, concentrations of MOSDAA and Triton X-114, equilibrium temperature, and equilibrium time, which affect both complexation and extraction, are optimized. Under the selected optimum conditions, the preconcentration of 10.0 mL, 0.1 μg mL−1 Co(II solution results in a limit of detection of 0.47 ng mL−1 (3σ and an enrichment factor of 19. A relative standard deviation of 2.78% (,  μg mL−1 for the determination of Co(II is obtained. The proposed method was applied for the determination of trace amounts of cobalt in river water and millet samples with satisfactory results.

  6. Determination of trace elements in Egyptian cane sugar (Deshna Factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analysis

    International Nuclear Information System (INIS)

    Multielement instrumental neutron activation (INAA), inductively coupled plasma-atomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses were utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth, respectively. (author)

  7. First observation of the strongly forbidden transition {sup 1}S{sub 0} - {sup 3}P{sub 0} in Strontium, for an atomic clock with trapped atoms; Premiere observation de la transition fortement interdite {sup 1}S{sub 0} - {sup 3}P{sub 0} du strontium, pour une horloge optique a atomes pieges

    Energy Technology Data Exchange (ETDEWEB)

    Courtillot, I

    2003-11-01

    This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the {sup 1}S{sub 0}-{sup 1}P{sub 1} transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition in {sup 87}Sr. This line has a theoretical natural width of 10{sup -3} Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

  8. Optical trapping of gold aerosols

    DEFF Research Database (Denmark)

    Schmitt, Regina K.; Pedersen, Liselotte Jauffred; Taheri, S. M.;

    2015-01-01

    Aerosol trapping has proven challenging and was only recently demonstrated.1 This was accomplished by utilizing an air chamber designed to have a minimum of turbulence and a laser beam with a minimum of aberration. Individual gold nano-particles with diameters between 80 nm and 200 nm were trapped...... in air using a 1064 nm laser. The positions visited by the trapped gold nano-particle were quantified using a quadrant photo diode placed in the back focal plane. The time traces were analyzed and the trapping stiffness characterizing gold aerosol trapping determined and compared to aerosol trapping...... of nanometer sized silica and polystyrene particles. Based on our analysis, we concluded that gold nano-particles trap more strongly in air than similarly sized polystyrene and silica particles. We found that, in a certain power range, the trapping strength of polystyrene particles is linearly decreasing...

  9. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    Energy Technology Data Exchange (ETDEWEB)

    Molaakbari, Elaheh [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Research Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mostafavi, Ali, E-mail: mostafavi.ali@gmail.com [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment and Nanochemistry Department, Research Institute of Environmental Science, International Center for Science, High Technology and Environmental Science, Kerman (Iran, Islamic Republic of); Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2011-01-30

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 {mu}L ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL{sup -1}, the detection limit was 0.37 ng mL{sup -1} (3S{sub b}/m, n = 7) and the relative standard deviation was {+-}1.63% (n = 7, C = 200 ng mL{sup -1}). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  10. Low interfacial trap density and high-temperature thermal stability in atomic layer deposited single crystal Y2O3/n-GaAs(001)

    Science.gov (United States)

    Lin, Yen-Hsun; Fu, Chien-Hua; Lin, Keng-Yung; Chen, Kuan-Hsiung; Chang, Tsong-Wen; Raynien Kwo, J.; Hong, Minghwei

    2016-08-01

    A low interfacial trap density (D it) of 2.2 × 1011 eV‑1 cm‑2 has been achieved with an atomic layer deposited (ALD) single crystal Y2O3 epitaxially on n-GaAs(001), along with a small frequency dispersion of 10.3% (2.6%/decade) at the accumulation region in the capacitance–voltage (C–V) curves. The D it and frequency dispersion in the C–V curves in this work are the lowest among all of the reported ALD-oxides on n-type GaAs(001). The D it was measured using the conductance–voltage (G–V) and quasi-static C–V (QSCV) methods. Moreover, the heterostructure was thermally stable with rapid annealing at 900 °C under various durations in He and N2, which has not been achieved in the heterostructures of ALD-Al2O3 or HfO2 on GaAs.

  11. The Interstellar Boundary Explorer (IBEX): Tracing the Interaction between the Heliosphere and Surrounding Interstellar Material with Energetic Neutral Atoms

    CERN Document Server

    Frisch, Priscilla C

    2010-01-01

    The Interstellar Boundary Explorer (IBEX) mission is exploring the frontiers of the heliosphere where energetic neutral atoms (ENAs) are formed from charge exchange between interstellar neutral hydrogen atoms and solar wind ions and pickup ions. The geography of this frontier is dominated by an unexpected nearly complete arc of ENA emission, now known as the IBEX 'Ribbon'. While there is no consensus agreement on the Ribbon formation mechanism, it seems certain this feature is seen for sightlines that are perpendicular to the interstellar magnetic field as it drapes over the heliosphere. At the lowest energies, IBEX also measures the flow of interstellar H, He, and O atoms through the inner heliosphere. The asymmetric helium profile suggests that a secondary flow of helium is present, such as would be expected if some fraction of helium is lost through charge exchange in the heliosheath regions. The detailed spectra characterized by the ENAs provide time-tagged samples of the energy distributions of the under...

  12. Cold and trapped metastable noble gases

    CERN Document Server

    Vassen, Wim; Leduc, Michèle; Boiron, Denis; Westbrook, Christoph I; Truscott, Andrew; Baldwin, Ken; Birkl, Gerhard; Cancio, Pablo; Trippenbach, Marek

    2011-01-01

    We review experimental and theoretical work on cold, trapped metastable noble gases. We emphasize the aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general. These aspects include detection techniques and collision processes unique to metastable atoms. We describe several experiments exploiting these unique features in fields including atom optics and statistical physics. We also discuss precision measurements on these atoms including fine structure splittings, isotope shifts, and atomic lifetimes.

  13. Flame Atomic Absorption Spectrometric Determination of Trace Amounts of Silver after Solid-Phase Extraction with 2-Mercaptobenzothiazole Immobilized on Microcrystalline Naphthalene

    Directory of Open Access Journals (Sweden)

    Farid Shakerian

    2013-01-01

    Full Text Available A simple and sensitive solid-phase extraction (SPE procedure combined with flame atomic absorption spectrometry (FAAS was designed for the extraction and determination of trace amounts of silver. A column of immobilized 2-mercaptobenzothiazole (MBT on microcrystalline naphthalene was used as the sorbent. Silver was quantitatively retained on the column in the pH range of 0.5–6.0. After extraction, the solid mass consisting of silver complex and naphthalene was dissolved out of the column with 5.0 mL of dimethylformamide, and the analyte was determined by flame atomic absorption spectrometry (FAAS. Under the optimum experimental conditions, the adsorption capacity was found to be 1.18 mg of silver per gram of the sorbent. A sample volume of 800 mL resulted in a preconcentration factor of 160. The relative standard deviation obtained for ten replicate determinations at a concentration of 0.8 µg L−1 was 1.4%, and the limit of detection was 0.02 µg L−1. The method was successfully applied to the determination of silver in radiology film, waste water, and natural water samples. The accuracy was examined by recovery experiments, independent analysis by electrothermal atomic absorption spectrometry, and analysis of two certified reference materials.

  14. Coherence in Microchip Traps

    CERN Document Server

    Treutlein, P; Steinmetz, T; Hänsch, T W; Reichel, J; Treutlein, Philipp; Hommelhoff, Peter; Steinmetz, Tilo; H\\"ansch, Theodor W.; Reichel, Jakob

    2003-01-01

    We report the coherent manipulation of internal states of neutral atoms in a magnetic microchip trap. Coherence lifetimes exceeding 1 s are observed with atoms at distances of $4-130 \\mu$m from the microchip surface. The coherence lifetime in the microtrap is independent of atom-surface distance and agrees well with the results of similar measurements in macroscopic magnetic traps. Due to the absence of surface-induced decoherence, a miniaturized atomic clock with a relative stability in the $10^{-13}$ range can be realized. For applications in quantum information processing, we propose to use microwave near-fields in the proximity of chip wires to create potentials that depend on the internal state of the atoms.

  15. Phosphorous trapped within buckminsterfullerene

    Science.gov (United States)

    Larsson, J. A.; Greer, J. C.; Harneit, W.; Weidinger, A.

    2002-05-01

    Under normal circumstances, when covalent molecules form, electrons are exchanged between atoms to form bonds. However, experiment and theoretical computations reveal exactly the opposite effect for the formation of group V elements nitrogen and phosphorous encapsulated within a buckminsterfullerene molecule. The C60 carbon cage remains intact upon encapsulation of the atom, whereas the electronic charge cloud of the N or P atom contracts. We have studied the chemical, spin, and thermodynamic properties of endohedral phosphorous (P@C60) and have compared our results with earlier findings for N@C60. From a combined experimental and theoretical vantage, we are able to elucidate a model for the interaction between the trapped group V atom and the fullerene cage. A picture emerges for the electronic structure of these complexes, whereby an atom is trapped within a fullerene, and interacts weakly with the molecular orbitals of the C60 cage.

  16. Determination of Trace Germanium in Marine Sediments by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS)

    Institute of Scientific and Technical Information of China (English)

    LI Jing; ZHAO Shilan; ZHANG Zhaohui; ZENG Xianjie

    2004-01-01

    A method for the analysis of trace germanium in marine sediments by HG-AFS has been investigated. The experimental conditions such as the acidity of reduction reaction, the amount of sodium boro-hydride, the carrier gas flow rate, etc., were tested and optimized by using a kind of orthogonal design. The detection limit of the presented method is 0.95 μg L-1 for germanium. The calibration curve shows a satisfactory line in the concentration range 0-320 μg L-1 Ge with a variation coefficient of ±2.1%.

  17. Determination of trace copper in food samples by flame atomic absorption spectrometry after solid phase extraction on modified soybean hull

    International Nuclear Information System (INIS)

    Soybean hull was chemically modified with citric acid and used as a solid phase extraction adsorbent for the determination of trace amounts of Cu2+ in food samples by flame absorption spectrometry (FAAS). The effect of pH, sample flow rate and volume, elution flow rate and volume and co-existing ions on the recovery of the analyte were investigated. The results showed that Cu2+ could be adsorbed on the modified soybean hull at pH 8.0 and eluted by 2.0 mL of 1.0 mol L-1 HCl. Under the optimized conditions, the adsorption capacity of modified soybean hull was found to be 18.0 mg g-1 for Cu2+. The detection limit of the proposed method was 0.8 ng mL-1 for Cu2+ with an enrichment factor of 18. The analytical result for the certified reference tea sample (GBW07605) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace Cu2+ in dried sweet potato, lake water and milk powder, the recovery of Cu2+ for spiked samples was between 91% and 109.6%.

  18. Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product

    OpenAIRE

    Joyce Nunes Bianchin; Eduardo Carasek; Edmar Martendal

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precisio...

  19. Trace and Essential Elements Analysis in Cymbopogon citratus (DC.) Stapf Samples by Graphite Furnace-Atomic Absorption Spectroscopy and Its Health Concern

    Science.gov (United States)

    Anal, Jasha Momo H.

    2014-01-01

    Cymbopogon citratus (DC.) Stapf commonly known as lemon grass is used extensively as green tea and even as herbal tea ingredient across the world. Plants have the ability to uptake metals as nutrient from the soil and its environment which are so essential for their physiological and biochemical growth. Concentrations of these twelve trace elements, namely, Mg, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Mo, As, Cd, and Pb, are analysed by graphite furnace-atomic absorption spectroscopy (GF-AAS) and are compared with the permissible limits of FAO/WHO, ICMR, and NIH, USA, which are found to be within permissible limits. Toxic metals like As, Cd, and Pb, analysed are within the tolerable daily diet limit and at low concentration. PMID:25525430

  20. Trace and Essential Elements Analysis in Cymbopogon citratus (DC. Stapf Samples by Graphite Furnace-Atomic Absorption Spectroscopy and Its Health Concern

    Directory of Open Access Journals (Sweden)

    Jasha Momo H. Anal

    2014-01-01

    Full Text Available Cymbopogon citratus (DC. Stapf commonly known as lemon grass is used extensively as green tea and even as herbal tea ingredient across the world. Plants have the ability to uptake metals as nutrient from the soil and its environment which are so essential for their physiological and biochemical growth. Concentrations of these twelve trace elements, namely, Mg, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Mo, As, Cd, and Pb, are analysed by graphite furnace-atomic absorption spectroscopy (GF-AAS and are compared with the permissible limits of FAO/WHO, ICMR, and NIH, USA, which are found to be within permissible limits. Toxic metals like As, Cd, and Pb, analysed are within the tolerable daily diet limit and at low concentration.

  1. The determination of trace amounts of heavy metals in waters by a flow-injection system including ion-exchange preconcentration and flame atomic absorption spectrometric detection

    International Nuclear Information System (INIS)

    The flow-injection system combines on-line ion-exchange preconcentration with atomic absorption spectrometry (a.a.s.) for the determination of traces (μg l-1) of heavy metals in water samples. A multifunctional rotary sampling valve which incorporated two parallel sampling columns allows sampling, exchange, elution and a.a.s. to be achieved sequentially. The increases in sensitivity for nickel, copper, lead and cadmium were 20-28-fold at a sampling rate of 40 h-1 with 5-ml samples. Relative standard deviations were 1.5-4.1%. The recoveries of these four metals added to tap, sea and polluted waters were generally satisfactory, except for cadmium in polluted water. The effects of column diameter and elution flow rates on sensitivity are discussed. Possible interferences are described. (Auth.)

  2. Flame atomic absorption spectrometric determination of trace quantities of cadmium in water samples after cloud point extraction in Triton X-114 without added chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of)]. E-mail: afkhami@basu.ac.ir; Madrakian, Tayyebeh [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of); Siampour, Hajar [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of)

    2006-11-16

    A new micell-mediated phase separation method for preconcentration of ultra-trace quantities of cadmium as a prior step to its determination by flame atomic absorption spectrometry has been developed. The method is based on the cloud point extraction (CPE) of cadmium in iodide media with Triton X-114 in the absence of any chelating agent. The optimal extraction and reaction conditions (e.g., acid concentration, iodide concentration, effect of time) were studied, and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 3-300 ng mL{sup -1} of cadmium. The detection limit of the method is 1.0 ng mL{sup -1} of cadmium. The interference effect of some anions and cations was also tested. The method was applied to the determination of cadmium in tap water, waste water, and sea water samples.

  3. Selective cloud point extraction and preconcentration of trace amounts of silver as a dithizone complex prior to flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Manzoori, Jamshid L.; Karim-Nezhad, Ghasem

    2003-05-19

    Dithizone (diphenylthiocarbazone) was used as a complexing agent in cloud point extraction for the first time and applied for selective preconcentration of trace amounts of silver. The analyte in the initial aqueous solution was acidified with sulfuric acid (pH<1) and Triton X-114 was added as a surfactant. After phase separation, based on the cloud point separation of the mixture, the surfactant rich phase was diluted with tetrahydrofuran (THF) and the analyte determined in the enriched solution by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, a preconcentration factor of 43 was obtained for only 10 ml of sample. The analytical curve was linear in the range of 3-200 ng ml{sup -1} and the limit of detection was 0.56 ng ml{sup -1}. The proposed method was applied to the determination of silver in water samples.

  4. Flame atomic absorption determination of trace amounts of cadmium after preconcentration using a thiol-containing task-specific ionic liquid.

    Science.gov (United States)

    Mohamadi, Maryam; Mostafavi, Ali

    2011-01-01

    Dispersive liquid-liquid microextraction (DLLME) based on a task-specific ionic liquid (TSIL) was developed for the extraction and preconcentration of trace amounts of cadmium from aqueous samples, followed by flame atomic absorption spectrometry (FAAS) determination. In the proposed approach, cadmium ions are extracted from aqueous samples using small volumes of trioctylmethylammonium thiosalicylate (TOMATS) dissolved in acetone. TOMATS is a thiol-containing TSIL that can form metal thiolate complexes due to the chelating effect of the ortho-positioned carboxylate group relative to the thiol functionality. The main parameters affecting the performance of DLLME based on TSIL, such as pH, amount of TOMATS, extraction time, injection volume, salt addition, and centrifugation time, were optimized. Under optimum conditions, an LOD of 1.16 ng/mL and a good RSD of 1.8% at 60.0 ng/mL were obtained (n=7). The proposed method was applied to tap water, wastewater, well water, and milk samples. The results showed that DLLME based on TSIL combined with FAAS is a rapid, simple, sensitive, selective, low cost, volatile organic solvent-free, and efficient analytical method for the separation and determination of trace amounts of cadmium ions. PMID:21797025

  5. Determination of trace aluminum in biological and water samples by cloud point extraction preconcentration and graphite furnace atomic absorption spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Sang Hongbo [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Liang Pei [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)], E-mail: liangpei@mail.ccnu.edu.cn; Du Dan [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)

    2008-06-15

    A cloud point extraction (CPE) method for the preconcentration of trace aluminum prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) has been developed. The CPE method is based on the complex of Al(III) with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP), and then entrapped in non-ionic surfactant Triton X-114. PMBP was used not only as chelating reagent in CPE preconcentration, but also as chemical modifier in GFAAS determination. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of PMBP and Triton X-114, equilibration temperature and time, were investigated in detail. An enrichment factor of 37 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of this method for Al(III) is 0.09 ng mL{sup -1}, and the relative standard deviation is 4.7% at 10 ng mL{sup -1} Al(III) level (n = 7). The proposed method has been applied for determination of trace amount of aluminum in biological and water samples with satisfactory results.

  6. Ultra-trace determination of silver in water samples by electrothermal atomic absorption spectrometry after preconcentration with a ligand-less cloud point extraction methodology

    Energy Technology Data Exchange (ETDEWEB)

    Manzoori, Jamshid L. [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)]. E-mail: manzoori@tabrizu.ac.ir; Abdolmohammad-Zadeh, Hossein [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Amjadi, Mohammad [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2007-06-01

    A very simple and ligand-less cloud point extraction (CPE) methodology for the preconcentration of ultra-trace amounts of silver as a prior step to its determination by electrothermal atomic absorption spectrometry (ETAAS) has been developed. The method is based on the extraction of silver at pH 9 by using non-ionic surfactant polyethyleneglycolmono-p-nonylphenylether (PONPE 7.5) without adding any chelating agent. Several important variables that affect the CPE efficiency and ETAAS signal were investigated and optimized. The preconcentration of 15 ml sample solution allowed us to achieve an enhancement factor of 60. The calibration graph using the preconcentration system was linear in the range of 5-100 ng l{sup -1} with a correlation coefficient of 0.9991. The lower limit of detection (3s) obtained in the optimal conditions was 1.2 ng l{sup -1}. The relative standard deviation (R.S.D.) for eight replicate determinations at 30 ng l{sup -1} Ag level was 4.2%. The proposed method was successfully applied to the ultra-trace determination of silver in water samples.

  7. Application of Graphene as a Sorbent for the Preconcentration and Determination of Trace Amounts of Mercury in Water Samples by Hydride Generation Atomic Fluorescence Spectrometry

    International Nuclear Information System (INIS)

    The potential of graphene as a solid-phase extraction adsorbent for the separation and preconcentration of mercury (Hg) was investigated. Hg2+ was found to be quantitatively adsorbed onto graphene within pH 6.0-8.0, and then completely eluted with 4.0 mL of nitric acid/methanol (1:1, v/v) solution at a flow rate of 2.0 mL min-1. A new method using a microcolumn packed with graphene as a sorbent was developed for the preconcentration of trace amount of Hg2+ prior to its determination by hydride generation atomic fluorescence spectrometry. Under the optimum experimental conditions, the detection limit of this method for Hg2+ was 5.0 ng L /sup -1/, with an enrichment factor of 15.0, and the relative standard deviation was 3.5 percentage at the 1.0 μg L-1 Hg /sup 2+/ level. The method was then applied for the determination of trace amount of Hg /sup 2/+ in water samples with satisfactory results. (author)

  8. Cold and trapped metastable noble gases

    NARCIS (Netherlands)

    Vassen, W.; Cohen-Tannoudji, C.; Leduc, M.; Boiron, D.; Westbrook, C.I.; Truscott, A.; Baldwin, K.; Birkl, G.; Cancio, P.; Trippenbach, M.

    2012-01-01

    Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general is emphasized. These aspects include detection techniques and collision processes unique to metastable atoms. Sever

  9. Atom Skimmers and Atom Lasers Utilizing Them

    Science.gov (United States)

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  10. Ultra-trace determination of methylmercuy in seafood by atomic fluorescence spectrometry coupled with electrochemical cold vapor generation.

    Science.gov (United States)

    Zu, Wenchuan; Wang, Zhenghao

    2016-03-01

    A homemade electrochemical flow cell was adopted for the determination of methylmercury. The cold vapor of mercury atoms was generated from the surface of glassycarbon cathode through the method of electrolytic reduction and detected by atomic fluorescence spectroscopy subsequently. The operating conditions were optimized with 2 ng mL(-1) methylmercury standard solution. The caliberation curve was favorably linear when the concentrations of standard HgCH3(+) solutions were in the range of 0.2-5 ng mL(-1)(as Hg). Under the optimized conditions, the limit of detection (LOD) for methylmercury was 1.88×10(-3)ng mL(-1) and the precision evaluated by relative standard deviation was 2.0% for six times 2 ng mL(-1) standard solution replicates. The terminal analytical results of seafood samples, available from local market, showed that the methylmercury content ranged within 3.7-45.8 ng g(-1). The recoveries for methylmercury spiked samples were found to be in the range of 87.6-103.6% and the relative standard deviations below 5% (n=6) were acquired, which showed this method was feasible for real sample analysis. PMID:26615576

  11. Hollow fiber based liquid-phase microextraction for the determination of mercury traces in water samples by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Garcia, Ignacio; Rivas, Ricardo E. [Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence ' Campus Mare Nostrum' , University of Murcia, E-30071 Murcia (Spain); Hernandez-Cordoba, Manuel, E-mail: hcordoba@um.es [Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence ' Campus Mare Nostrum' , University of Murcia, E-30071 Murcia (Spain)

    2012-09-19

    Highlight: Black-Right-Pointing-Pointer Hg (II) traces are preconcentrated by means of a three-phase liquid microextraction system. Black-Right-Pointing-Pointer PAN and ammonium iodide are used in the donor and acceptor phase, respectively. Black-Right-Pointing-Pointer Hollow-fiber pores are continuously fed with toluene placed in the lumen. Black-Right-Pointing-Pointer Mercuric ions can be measured in waters below the {mu}g L{sup -1} level. - Abstract: A three-phase liquid microextraction procedure for the determination of mercury at low concentrations is discussed. To the aqueous sample placed at pH 7 by means of a phosphate buffer, 0.002% (m/v) 1-(2-pyridylazo)-2-naphthol (PAN) is incorporated, and the mixture submitted to microextraction with a hollow-fiber impregnated with toluene and whose lumen contains a 0.05 mol L{sup -1} ammonium iodide solution. The final measurement of the extract is carried out by electrothermal atomic absorption spectrometry (300 Degree-Sign C and 1100 Degree-Sign C for the calcination and atomization temperatures, respectively). The pyrolytic graphite atomizer is coated electrolytically with palladium. An enrichment factor of 270, which results in a 0.06 {mu}g L{sup -1} mercury for the detection limit is obtained. The relative standard deviation at the 1 {mu}g L{sup -1} mercury level is 3.2% (n = 5). The reliability of the procedure is verified by analyzing waters as well as six certified reference materials.

  12. Coprecipitation of trace amounts of silicon with aluminum hydroxide and the determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2014-01-01

    Full Text Available A simple preconcentration method of silicon based on coprecipitation with aluminum hydroxide prior to its flame atomic absorption (FAAS determination was established. The recovery values of analyte ion was higher than 95%. The parameters including types of hydroxide ion source for precipitation, acid type for dissolution step, amount of aluminum ion as collector, pH, temperature, standing and centrifuge time, and sample volume were optimized for the quantitative recovery of the analyte. The influences of matrix ions were also examined. The relative standard deviation was found to be 3.2%. The limit of detection was calculated as (0.1 mg L-1. The preconcentration factor is 100 for (200 mL solution. The proposed method was successfully applied for the determination of silicon in some water and alloy samples.

  13. Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Waheed, S.; Siddique, N.; Rahman, S. [Chemistry Div., Directorate of Science, Pakistan Inst. of Nuclear Science and Tech., Islamabad (Pakistan)

    2009-07-01

    Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

  14. Determination of platinum traces contamination by graphite furnace atomic absorption spectrometry after preconcentration by cloud point extraction

    International Nuclear Information System (INIS)

    A simple and sensitive method is described for the determination of platinum surface contamination originating from cisplatin, carboplatin and oxaliplatin. Following extraction from swabs and preconcentration with the cloud point extraction (CPE) method, detection was by graphite furnace atomic absorption spectrometry (GFAAS). After desorption of platinum compounds from the swab, CPE involved on preconcentration of platinum in aqueous solution with diethyldithiocarbamate (DDTC) as chelating agent and Triton X-114 as extraction medium. DDTC is not only a chelating agent, but may also be a good candidate for the inactivation of platinum compounds. DDTC is recommended by the Word Health Organization (WHO) for the destruction of platinum-based anticancer drugs. The main factors affecting CPE efficiency, pH of the sample solution, concentrations of DDTC and Triton X-114, equilibration temperature and incubation time, were evaluated in order to enhance sensitivity of the method. The desorption of platinum compounds from the swab was investigated in parallel. Since platinum is bound to DDTC, it must exchange with copper in order to enhance platinum atomizing by GFAAS. A preconcentration factor of 29 was obtained for 10 mL of a platinum solution at 10 μg mL-1. In optimal conditions, the limit of detection was 0.2 ng mL-1, corresponding to 2.0 ng of platinum metal on the swab. Absorbance was linear between 0.7 and 15 ng mL-1. The proposed method was applied for the determination of surface contamination by platinum compounds with correct results.

  15. Determination of platinum traces contamination by graphite furnace atomic absorption spectrometry after preconcentration by cloud point extraction

    Energy Technology Data Exchange (ETDEWEB)

    Chappuy, M. [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France); Caudron, E., E-mail: eric.caudron@eps.aphp.fr [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France); Groupe de Chimie Analytique de Paris-Sud, EA 4041, IFR 141, School of Pharmacy, Univ Paris-Sud, 92296 Chatenay-Malabry (France); Bellanger, A. [Department of Pharmacy, Pitie-Salpetriere Hospital (Paris Public Hospital Authority), 47 boulevard de l' hopital, 75013 Paris (France); Pradeau, D. [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France)

    2010-04-15

    A simple and sensitive method is described for the determination of platinum surface contamination originating from cisplatin, carboplatin and oxaliplatin. Following extraction from swabs and preconcentration with the cloud point extraction (CPE) method, detection was by graphite furnace atomic absorption spectrometry (GFAAS). After desorption of platinum compounds from the swab, CPE involved on preconcentration of platinum in aqueous solution with diethyldithiocarbamate (DDTC) as chelating agent and Triton X-114 as extraction medium. DDTC is not only a chelating agent, but may also be a good candidate for the inactivation of platinum compounds. DDTC is recommended by the Word Health Organization (WHO) for the destruction of platinum-based anticancer drugs. The main factors affecting CPE efficiency, pH of the sample solution, concentrations of DDTC and Triton X-114, equilibration temperature and incubation time, were evaluated in order to enhance sensitivity of the method. The desorption of platinum compounds from the swab was investigated in parallel. Since platinum is bound to DDTC, it must exchange with copper in order to enhance platinum atomizing by GFAAS. A preconcentration factor of 29 was obtained for 10 mL of a platinum solution at 10 {mu}g mL{sup -1}. In optimal conditions, the limit of detection was 0.2 ng mL{sup -1}, corresponding to 2.0 ng of platinum metal on the swab. Absorbance was linear between 0.7 and 15 ng mL{sup -1}. The proposed method was applied for the determination of surface contamination by platinum compounds with correct results.

  16. Atomic Physics

    CERN Document Server

    Foot, Christopher J

    2007-01-01

    This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen

  17. Temporal Windowing of Trapped States

    CERN Document Server

    Castellano, L M

    2001-01-01

    Trapped state definition for 3-level atoms in Lambda configuration, is a very restrictive one, and for the case of unpolarized beams, this definition no longer holds.We introduce a more general definition by using a reference frame rotating with the frequency of the control field, obtaining a temporal windowing for the trapped population.This amounts to a time quantization of the coherent population transfer, making possible to study the phase coherence in trapped light.

  18. Ultrasound-assisted dispersive liquid-liquid microextraction for the speciation of traces of chromium using electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    López-García, Ignacio; Briceño, Marisol; Vicente-Martínez, Yesica; Hernández-Córdoba, Manuel

    2013-10-15

    A microextraction procedure for the speciation of very low concentrations (0.005-0.2 µg L(-1)) of chromium is discussed. To the aqueous sample (10 mL), diluted hydrochloric acid, sodium chloride and a small amount of tributylphosphate (80 µL) are incorporated, and the mixture is submitted to ultrasounds for 10 min. The organic phase recovered after centrifuging is injected into the electrothermal atomizer, and the signal due to hexavalent chromium obtained. The repetition of the procedure using another aliquot in which all the chromium present is oxidized to Cr (VI) allows the Cr(III) content to be obtained by difference. The enrichment factor is 240 and the detection limit 0.002 µg L(-1) chromium. The relative standard deviation for ten consecutive microextractions of a 0.1 µg L(-1) chromium solution is close to 8%. The procedure is applied to waters and to the leachates obtained from low cost toys made of plastic materials. PMID:24054574

  19. Determination of Trace Amounts of Nickel (Ⅱ) by Graphite Furnace Atomic Absorption Spectrometry Coupled with Cloud Point Extraction

    Institute of Scientific and Technical Information of China (English)

    SHAH Syed Mazhar; WANG Hao-nan; SU Xing-guang

    2011-01-01

    A new method based on the cloud point extraction(CPE) for separation and preconcentration of nickel(Ⅱ)and its subsequent determination by graphite furnace atomic absorption spectrometry(GFAAS) was proposed,8-hydroxyquinoline and Triton X-100 were usedl as the ligand and surfactant respectively. Nickel(Ⅱ) can form a hydrophobic complex with 8-hydroxyquinoline, the complex can be extracted into the small volume surfactant rich phase at the cloud point temperature(CPT) for GFAAS determination. The factors affecting the cloud point extraction,such as pH, ligand concentration, surfactant concentration, and the incubation time were optimized. Under the optimal conditions, a detection limit of 12 ng/L and a relative standard deviation(RSD) of 2.9% were obtained for Ni(Ⅱ) determination. The enrichment factor was found to be 25. The proposed method was successfully applied to the determination of nickel(Ⅱ) in certified reference material and different types of water samples and the recovery was in a range of 95% 103%.

  20. The use of ion chromatography-dc plasma atomic emission spectrometry for the speciation of trace metals

    Energy Technology Data Exchange (ETDEWEB)

    Urasa, I.T.

    1991-09-20

    The original objects of this research program were: to interface d.c. plasma atomic emission spectrometer with an ion chromatograph; to characterize and optimize the combined systems for application in the speciation of metals in aqueous solutions; to use this system in the study of the solution chemistry of various metals; and to find ways in which the measurement sensitivity of the method can be enhanced, thereby allowing the detection of metal species at low ppb concentration levels. This approach has been used to study the chemistry of and speciate several elements in solution including: arsenic, chromium, iron, manganese, nickel phosphorus, platinum, selenium, and vanadium. During the course of this research, we have found that the solution chemistry of the elements studied and the speciation data obtained can vary considerably depending on the solution, and the chromatographic conditions employed. The speciation of chromium, iron, and vanadium was found to be highly influenced by the acidity of the sample. The element selective nature of the d.c. plasma detector allows these changes to be monitored, thereby providing quantitative information on the new moieties formed. New approaches are being developed including the use of chelating ligands as preconcentration agents for purposes of reducing further the detection limits of the elements of interest and to improve the overall element speciation scheme. New thrusts are being directed towards the employment of post-column derivatization method coupled with colorimetric measurements to detect and quantify metal species eluting from the chromatographic column. The influence of sample acidity on these investigations will be carefully evaluated. These new thrusts are described in the accompanying Project Renewal Proposal.

  1. Liquid-liquid extraction of molybdenum and its ultra-trace determination by graphite furnace atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    A highly sensitive and reliable method for the determination of molybdenum at nanogram level in rocks, ores, minerals, soils and hydrogeochemical samples has been developed by liquid-liquid extraction of the metal into a suitable organic solvent, followed by its measurement by Graphite Furnace Atomic Absorption Spectrophotometer. Molybdenum in the sample (∼200 mesh) was opened by NH4HF2 and H2SO4 dissolution. At pH 4-6, major matrix elements like Fe, Ti, Nb, Cu, Th, REEs etc are removed by the solvent extraction of the complexes of these elements with the, O-O' type of ligand, 2,3 dihydroxynaphthalene (2,3 H2ND) leaving Mo (VI) in aqueous solution. Subsequently, Mo (VI) was reduced with hydroxylamine hydrochloride to Mo (V) which was allowed to form a 1:2 complex with the cited ligand, 2,3 H2ND at pH 2-4. At this very pH, the Mo (V)-2,3 H2ND neutral complex was readily extracted in ethyl or butyl acetate. Then Mo (V) was stripped off into aqueous solution (minimum volume). This solution was fed into the graphite furnace through an auto sampler. The concentration of the analyte in the sample was found out/read from the calibration curve prepared against known standards. The method was validated by applying it on a host of rock samples including Geological Reference Materials and water samples. Molybdenum can be estimated up to 1 μg per gram rock sample with a precision of 2.0% and 2 ppb in water samples with a precision of ±5%. (author)

  2. Quantum simulations with cold trapped ions

    Science.gov (United States)

    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.

  3. Selective quantification of trace palladium in road dusts and roadside soils by displacement solid-phase extraction online coupled with electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Fang, Jing; Jiang, Yan; Yan, Xiu-Ping; Ni, Zhe-Ming

    2005-01-01

    There is a growing concern about the effect of palladium on human health because of the toxicity and increasing occurrence of palladium as a result of its extensive use in automotive catalytic converters. Development of reliable analytical methodologies for the determination of palladium in environmental materials is of great importance for critical evaluation of the possible risks for human health. In this work, a displacement solid-phase extraction technique was developed and online coupled to electrothermal atomic absorption spectrometry (ETAAS) for selective and sensitive determination of trace palladium in environmental samples without need of any special selective complexing agents, selective sorbents, and masking agents. The developed methodology involved the online formation of copper pyrrolidine dithiocarbamate (Cu-PDC), and the resultant Cu-PDC was extracted onto a microcolumn packed with the sorbent from a cigarette filter. Trace Pd(II) was selectively preconcentrated through loading the sample solution onto the microcolumn by online displacement reaction between Pd(II) and the extracted Cu-PDC on the microcolumn. The retained analyte was subsequently eluted with 40 microL of ethanol for online ETAAS determination. Interferences from coexisting heavy metal ions with lower stability of their PDC complexes relative to Cu-PDC were minimized. The tolerable concentrations of Cd-(II), Fe(III), Co(II), Mn(II), Cr(III), and Zn(II) were up to 2, 6, 40, 2, 1.5, and at least 100 mg L(-1), respectively. Compared with conventional solid-phase extraction methodology, the developed displacement solid-phase extraction protocol gave 2-4 orders of magnitude improvement in the maximum tolerable concentrations of coexisting heavy metal ions. With the consumption of only 2.8 mL of sample solution, an enhancement factor of 52 and a detection limit (3sigma) of 18 ng L(-1) were achieved at a sample throughput of 30 samples h(-1). The precision (RSD, n = 13) was 2.5% at the 1

  4. Trapping of photophoretic particles

    CERN Document Server

    Magiera, Martin P

    2014-01-01

    A trapping mechanism for self-propelled particles based on an inhomogeneous drive is presented and studied analytically as well as by computer simulations. In experiments this method can be realized using photophoretic Janus particles driven by a light source, which shines through a shading mask and leads to an accumulation of the swimmers in the shaded part. The mechanism can be traced back to a finite penetration depth of particles impinging from the illuminated part of the system into the shaded part.

  5. Extraction and preconcentration of trace levels of cobalt using functionalized magnetic nanoparticles in a sequential injection lab-on-valve system with detection by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: An approach to performing extraction and preconcentration employing functionalized magnetic particles for the determination of cobalt in the sequential injection lab-on-valve system using detection by electrothermal atomic absorption spectrometry. Highlights: ► New SPE method for cobalt separation/preconcentration was reported. ► Functionalized magnetic nanoparticles were used as adsorbent. ► Extraction, elution, and detection procedures were performed in the LOV system. ► This automatic extraction technique provided a good platform for metal analysis. - Abstract: A new approach to performing extraction and preconcentration employing functionalized magnetic nanoparticles for the determination of trace metals is presented. Alumina-coated iron oxide nanoparticles were synthesized and used as the solid support. The nanoparticles were functionalized with sodium dodecyl sulfate and used as adsorbents for solid phase extraction of the analyte. Extraction, elution, and detection procedures were performed sequentially in the sequential injection lab-on-valve (SI-LOV) system followed by electrothermal atomic absorption spectrometry (ETAAS). Mixtures of hydrophobic analytes were successfully extracted from solution using the synthesized magnetic adsorbents. The potential use of the established scheme was demonstrated by taking cobalt as a model analyte. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 0.01–5 μg L−1, and the relative standard deviation was 2.8% at the 0.5 μg L−1 level (n = 11). The limit of detection was 6 ng L−1 with a sampling frequency of 18 h−1. The present method has been successfully applied to cobalt determination in water samples and two certified reference materials.

  6. Atoms Talking to SQUIDs

    CERN Document Server

    Hoffman, J E; Kim, Z; Wood, A K; Anderson, J R; Dragt, A J; Hafezi, M; Lobb, C J; Orozco, L A; Rolston, S L; Taylor, J M; Vlahacos, C P; Wellstood, F C

    2011-01-01

    We present a scheme to couple trapped $^{87}$Rb atoms to a superconducting flux qubit through a magnetic dipole transition. We plan to trap atoms on the evanescent wave outside an ultrathin fiber to bring the atoms to less than 10 $\\mu$m above the surface of the superconductor. This hybrid setup lends itself to probing sources of decoherence in superconducting qubits. Our current plan has the intermediate goal of coupling the atoms to a superconducting LC resonator.

  7. Analysis of trace mercury in water by solid phase extraction using dithizone modified nanometer titanium dioxide and cold vapor atomic absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new method for analysis of trace mercury in water samples was developed, based on the combination of preconcentration/separation using dithizone-modified nanometer titanium dioxide (TiO2) as a solid phase extractant and determination by cold vapor atomic adsorption spectrometry (CVAAS). Dithizone was dissolved with alcohol and loaded on the surface of nano-sized TiO2 powders by stirring. The static adsorption behavior of Hg2+ on the dithizone-modified nanoparticles was investigated in detail. It was found that excellent adsorption ratio for Hg2+ could be obtained in the pH range of 7-8 with an oscillation time of 15 min, and a 5 mL of 3.5 mol·L-1 HCl solution could quantitatively elute Hg2+ from nanometer TiO2 powder. Common coexisting ions caused no obvious influence on the determination of mercury. The mechanisms for the adsorption and desorption were discussed. The detection limit (3σ) for Hg2+ was calculated to be 5 ng·L-1. The proposed method was applied to the determination of Hg2+ in a mineral water sample and a Zhujiang River water sample. By the standard addition method, the average recoveries were found to be 94.4%-108.3% with RSD (n = 5) of 2.9%-3.5%.

  8. Separation and preconcentration of trace quantities of copper ion using modified alumina nanoparticles, and its determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    We report on a sensitive, reliable and relatively fast method for separation, preconcentration and determination of trace quantities of copper(II) ion. It is making use of nanometer-sized γ-alumina nanoparticles modified with sodium dodecyl sulfate (SDS). The adsorptive potential was assessed via a Langmuir isotherm and the maximal sorption capacity was found to be 138 mg g-1. The effects of pH values, amount of ligand, flow rate, type of eluting agent, volume of eluent, and the volume of sample were examined. The effects of interfering ions on the recovery of the analyte were also investigated. Copper ion was then determined by flame atomic absorption spectrometry. The relative standard deviation for five replicate determinations (at 50 μg L-1 of copper) is 3.3%. The detection limit (at 3 s) is 2.5 μg L-1. This method was validated with a certified reference material of oyster tissue (NIST SRM 1566b) and the results coincided well with the certified values. The procedure was successfully applied to the determination of Cu in water and food samples. (author)

  9. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples.

    Science.gov (United States)

    Wang, Yukun; Gao, Shutao; Zang, Xiaohuan; Li, Jingci; Ma, Jingjun

    2012-02-24

    Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 μg L(-1) with a detection limit of 0.61 μg L(-1). The relative standard deviation for ten replicate measurements of 20.0 and 400.0 μg L(-1) of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes. PMID:22284885

  10. Determination of trace levels of dissolved vanadium in seawater by use of synthetic complexing agents and inductively coupled plasma-atomic emission spectroscopy (ICP-AES)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasse, G.; Ouddane, B.; Fischer, J.C. [Univ. des Sciences et Technologies et Lille, Lab. de Chimie Analytique et Marine (ELICO), UPRESA CNRS 8013, Villeneuve d' Ascq (France)

    2002-11-01

    In the determination of traces of dissolved vanadium in complex matrices such as seawater, separation and enrichment from the matrix is of special importance. A wide variety of methods has been proposed for preconcentration, depending to the nature of samples and the methods to be used for measurement. Among these methods separation techniques based on sorption on to chelating resins seem convenient, rapid, and capable of achieving a high concentration factor. The methods proposed in this paper are based on the transformation of all dissolved vanadium species in seawater into organic complexes by use of synthetic complexing agents such as dithizone, luminol, or 8-hydroxyquinoline; the resulting vanadium-organic complexes were sorbed on to a C{sub 18} column at a flow rate of 5 mL min{sup -1}. The vanadium sorbed on the C{sub 18} columns was then stripped by use of nitric acid (2 mol L{sup -1}) and analysed by inductively coupled plasma-atomic emission spectroscopy, ICP-AES. This method was optimised and use of other chelating resins, such as chelamine, chelex-100, and immobilised 8-hydroxyquinoline and was compared by passing seawater samples directly over the resins. The experimental conditions (pH, acid used for elution, and contact time between the liquid sample and the resin) were optimised. The results were compared for all the resins used and were indicative of excellent and coherent reproducibility. (orig.)

  11. Ultrasound-assisted ion-pair dispersive liquid-liquid microextraction of trace amounts of lead in water samples prior to graphite furnace atomic absorption spectrometry determination.

    Science.gov (United States)

    Afzali, Daryoush; Mohadesi, Ali Reza; Falahnejad, Masoumeh; Bahadori, Behnoosh

    2013-01-01

    A new ion-pair dispersive liquid-liquid microextraction method is described for separation and preconcentration of trace amounts of lead in different water samples. Graphite furnace atomic absorption spectrometry was used for determination of lead. The ion association complex between lead and iodide ions that forms is PbI4(-2)-tetradecyl-dimethylbenzylammonium, which is extracted into fine droplets of chlorobenzene. In order to reach the optimized experimental conditions, the influence of different parameters, such as concentration of KI, nature and volume of extraction solvents, pH effect, extraction time, and the period and speed of sonication and centrifugation, were optimized. The LOD was 0.08 ng/mL and the linear dynamic range was 0.20-8.0 ng/mL in initial solution with a correlation coefficient of 0.9985. Under the optimum conditions, the enrichment factor was 555.5. The proposed method was successfully applied for separation and determination of lead in sea, rain, river, and drinking water samples. PMID:23513972

  12. Flame atomic absorption spectrometric determination of trace cadmium in alloys and biological samples after solid-liquid extraction and preconcentration with use of nitroso-S

    International Nuclear Information System (INIS)

    Cadmium is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium chloride (TDBA) on microcrystalline naphthalene in the pH range 5.7-10.5 from a large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of cadmium complex and naphthalene is dissolved with 5 mL of dimethylformamide and the metal was determined by flame atomic absorption spectrometric. Cadmium complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined similarly. About 25 ng of cadmium can be concentrated in a column from 500 mL of aqueous sample, where its concentration is as low as 0.05 ng/mL. Eight replicate determinations of 0.1 μg/mL of cadmium in final DMF solution gave a mean absorbance of 0.060 with a relative standard deviation of 1.8 %. The sensitivity for 1 % absorption was 7.3 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of cadmium in various alloys and biological samples. (author)

  13. Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

    International Nuclear Information System (INIS)

    A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L-1 nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples

  14. Ultrasound-assisted emulsification solidified floating organic drops microextraction of ultra trace amount of Te (IV) prior to graphite furnace atomic absorption spectrometry determination.

    Science.gov (United States)

    Fathirad, Fariba; Afzali, Daryoush; Mostafavi, Ali; Ghanbarian, Maryam

    2012-01-15

    In the present study, a new, simple and efficient method for the preconcentration of ultra trace amounts of Te (IV) is developed using ultrasound-assisted emulsification solidified floating organic drops microextraction (USAE-SFODME) before graphite furnace atomic absorption spectrometry determination. In this method, tellurium is extracted into the fine droplets of 1-undecanol after chelate formation with the water soluble ligand, ammonium pyrrolidinedithiocarbamate (APDC). Several factors such as pH, chelating agent amount, type and volume of the extracting solvent, sonication and centrifuging time that influence the extraction and complex formation are optimized. Under the optimum conditions, the calibration graph is linear in the range of 0.01-0.24ngmL(-1) of tellurium in the original solution, with limit of detection of 0.003ngmL(-1). The relative standard deviation (RSD) for seven replicated determinations of tellurium ion at 0.08ngmL(-1) concentration level is calculated as 3.4%. The proposed method was successfully applied to the determination of Te (IV) in a standard soil and several water samples. PMID:22265571

  15. Ultrasound-assisted emulsification microextraction based on solidification floating organic drop trace amounts of manganese prior to graphite furnace atomic absorption spectrometry determination.

    Science.gov (United States)

    Mohadesi, Alireza; Falahnejad, Masoumeh

    2012-01-01

    In the present study, an ultrasound-assisted emulsification microextraction based on solidification floating organic drop method is described for preconcentration of trace amounts of Mn (II). 2-(5-Bromo-2-pyridylazo)-5 diethylaminophenol was added to a solution of Mn(+2) at ph = 10.0. After this, 1-undecanol was added to the solution as an extraction solvent, and solution was stirred. Several factors influencing the microextraction efficiency, such as pH, the amount of chelating agent, nature and volume of extraction solvent, the volume of sample solution, stirring rate, and extraction time were investigated and optimized. Then sample vial was cooled by inserting into an ice bath, and the solidified was transferred into a suitable vial for immediate melting. Finally the sample was injected into a graphite furnace atomic absorption spectrometry. Under the optimum condition the linear dynamic range was 0.50-10.0 ng mL(-1) with a correlation coefficient of 0.9926, and the detection limit of 0.3 ng mL(-1) was obtained. The enrichment factor was 160. The proposed method was successfully applied for separation and determination of manganese in sea, rain, tap, and river water samples. PMID:22645504

  16. Development of on-line single-drop micro-extraction sequential injection system for electrothermal atomic absorption spectrometric determination of trace metals

    International Nuclear Information System (INIS)

    A novel automatic sequential injection (SI) single-drop micro-extraction (SDME) system is proposed as versatile approach for on-line metal preconcentration and/or separation. Coupled to electrothermal atomic absorption spectrometry (ETAAS) the potentials of this SI scheme are demonstrated for trace cadmium determination in water samples. A non-charged complex of cadmium with ammonium diethyldithiophosphate (DDPA) was produced and extracted on-line into a 60 μL micro-drop of di-isobutyl ketone (DIBK). The extraction procedure was performed into a newly designed flow-through extraction cell coupled on a sequential injection manifold. As the complex Cd(II)-DDPA flowed continuously around the micro-droplet, the analyte was extracting into the solvent micro-drop. All the critical parameters were optimized and offered good performance characteristics and high preconcentration ratios. For 600 s micro-extraction time, the enhancement factor was 10 and the sampling frequency was 6 h-1. The detection limit was 0.01 μg L-1 and the precision (RSD at 0.1 μg L-1 of cadmium) was 3.9%. The proposed method was evaluated by analyzing certified reference material

  17. Determination of trace copper in water samples by flame atomic absorption spectrometry after preconcentration on a phosphoric acid functionalized cotton chelator

    Directory of Open Access Journals (Sweden)

    XINGYAN LIU

    2008-02-01

    Full Text Available This paper reports the preparation of a phosphorylated cotton chelator (PCC by solid phase esterification of phosphoric acid (PA onto defatted cotton fibres using urea as the catalyst. The synthesized PCC was employed for the preconcentration of copper from water samples prior to its determination by flame atomic absorption spectrometry (FAAS. The preconcentration of copper was studied under both batch and column techniques. The pH range for the quantitative preconcentration of copper was 4.0–7.0. The sorption time required for each sample was less than 30 min by the batch method. The copper sorption capacity of the PCC was found to be 15.3 mg/g at the optimum pH value. Elution with 1.0 mol dm-3 hydrochloric acid was found to be quantitative. Feasible flow rates of the copper solution for quantitative sorption onto the column packed with PCC were 0.5–4.0 ml min-1, whereas the optimum flow rate of the hydrochloric acid solution for desorption was less than 1.5 ml min-1. An 80-fold preconcentration factor could be achieved under the optimum column conditions. The tolerance limits for common metal ions on the preconcentration of copper and the number of times of column reuse were investigated. The proposed method was successfully applied for the preconcentration and determination of trace copper in natural and drinking water samples by FAAS.

  18. Novel extraction induced by emulsion breaking as a tool for the determination of trace concentrations of Cu, Mn and Ni in biodiesel by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Pereira, Fernanda M; Zimpeck, Renata C; Brum, Daniel M; Cassella, Ricardo J

    2013-12-15

    This work proposes a novel method for the determination of trace concentrations of Cu, Mn and Ni in biodiesel samples by electrothermal atomic absorption spectrometry. In order to overcome problems related to the organic matrix in the direct introduction of the samples, a new extraction approach was investigated. The method was based on the extraction induced by emulsion breaking, in which metals were transferred from the biodiesel to an acid aqueous phase after formation and breaking of a water-in-oil emulsion prepared by mixing the biodiesel sample with an aqueous solution containing surfactant and nitric acid. Several parameters that could influence the performance of the system were evaluated. Quantitative extractions of the analytes were obtained when the extraction was performed using an emulsifier solution containing 2.1 mol L(-1) of HNO3 and 7% m/v of Triton X-100. The extraction time had remarkable influence on the efficiency of the process, being necessary an agitation time of 60 min to achieve maximum extraction. The limits of quantification were below 1 µg L(-1) for the three analytes under study. The accuracy of the method was tested by application of a recovery test (recovery percentages between 89% and 109% were observed) and by comparison with a well-established method, taken as reference. PMID:24209306

  19. Synthesis, characterization and application of a new chelating resin for solid phase extraction, preconcentration and determination of trace metals in some dairy samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Daşbaşı, Teslima; Saçmacı, Şerife; Çankaya, Nevin; Soykan, Cengiz

    2016-11-15

    In this study, a simple and rapid solid phase extraction/preconcentration procedure was developed for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly(N-cyclohexylacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) (NCA-co-DVB-co-AMPS) (hereafter CDAP) was synthesized and characterized. The influences of the analytical parameters such as pH of the sample solution, type and concentration of eluent, flow rates of the sample and eluent, volume of the sample and eluent, amount of chelating resin, and interference of ions were examined. The limit of detection (LOD) of analytes were found (3s) to be in the range of 0.65-1.90μgL(-1). Preconcentration factor (PF) of 200 and the relative standard deviation (RSD) of ⩽2% were achieved (n=11). The developed method was applied for determination of analytes in some dairy samples and certified reference materials. PMID:27283608

  20. Lindblad Equation for the Inelastic Loss of Ultracold Atoms

    CERN Document Server

    Braaten, Eric; Lepage, G Peter

    2016-01-01

    The loss of ultracold trapped atoms due to deeply inelastic reactions has previously been taken into account in effective field theories for low-energy atoms by adding local anti-Hermitian terms to the effective Hamiltonian. Here we show that when multi-atom systems are considered, an additional modification is required in the equation governing the density matrix. We define an effective density matrix by tracing over the states containing high-momentum atoms produced by deeply inelastic reactions. We show that it satisfies a Lindblad equation, with local Lindblad operators determined by the local anti-Hermitian terms in the effective Hamiltonian. We use the Lindblad equation to derive the universal relation for the two-atom inelastic loss rate for fermions with two spin states and the universal relation for the three-atom inelastic loss rate for identical bosons.

  1. Atom cooling with an atom-optical diode on a ring

    OpenAIRE

    Ruschhaupt, A.; Muga, J. G.

    2008-01-01

    We propose a method to cool atoms on a ring by combining an atom diode -a laser valve for one-way atomic motion which induces robust internal state excitation- and a trap. We demonstrate numerically that the atom is efficiently slowed down at each diode crossing, and it is finally trapped when its velocity is below the trap threshold.

  2. 全光学冷却与囚禁133Cs原子玻色-爱因斯坦凝聚的可能性%POSSIBILITY OF ALL OPTICALLY-COOLED AND TRAPPED 133Cs ATOMIC BEC

    Institute of Scientific and Technical Information of China (English)

    印建平; 高伟建; 刘南春; 王义遒

    2001-01-01

    The experimental progress on rf evaporative cooling of 133Cs atomic sample in recent year is reviewed, and the difficulty of magnetically trapped 133Cs atomic Bose-Einstein condensation (BEC) is analyzed. In this paper, we propose an all-optically-cooled and -trapped 133Cs BEC scheme, which is composed of a pyramidal-hollow-beam gravito-optical trap (PHB GOT) from a diode laser (λ=0.852 μm) and a conical-hollow-beam (CHB) GOT from an Ar+ laser (=0.5013 μm). In the PHB GOT, the cold atoms experience an efficient hollow-beam induced Sisyphus cooling (i.e., intensity gradient cooling) and repumpimg-beam induced geometric cooling, and they will be cooled to a few photon-recoil limits (~2 μK) from MOT's temperature (~60 μK). Whereas in the Ar+ hollow-laser-beam trap, cold atoms will be further cooled by Raman cooling (or velocity-selection coherent population trapping) and compressed by a blue-detuned covering beam. We have performed Monte-Carlo simulations for PHB cooling process, calculated the optical potential for 133Cs atoms in Ar+ hollow laser beam, and estimated total collision loss and atomic density. Our study shows that the realization of an optically-cooled and -trapped BEC of 133Cs atoms may be possible in our all-optical dipole trap.%综述了近年来有关蒸发冷却133Cs原子样品的实验进展,分析了磁囚禁133Cs原子玻色-爱因斯坦凝聚(BEC)的困难,并在此基础上提出了一个全光型冷却与囚禁133Cs原子BEC的新方案.该方案主要由一个来自半导体激光(λ=0.852 μm)的倒金字塔形中空光束重力光学囚禁(pyramidal-hollow-beam gravito-optical trap,缩写为PHB GOT)和一个来自Ar+激光(=0.5013 μm)的圆锥形中空光束重力光学囚禁(conical-hollow-beam gravito-optical trap,缩写为CHB GOT)组成.在PHB GOT中,冷原子经历了一个有效的中空光束感应的Sisyphus冷却(也即强度梯度冷却)和抽运光感应的几何冷却,原子温度将被从

  3. Moving Single Atoms

    Science.gov (United States)

    Stuart, Dustin

    2016-05-01

    Single neutral atoms are promising candidates for qubits, the fundamental unit of quantum information. We have built a set of optical tweezers for trapping and moving single Rubidium atoms. The tweezers are based on a far off-resonant dipole trapping laser focussed to a 1 μm spot with a single aspheric lens. We use a digital micromirror device (DMD) to generate dynamic holograms of the desired arrangement of traps. The DMD has a frame rate of 20 kHz which, when combined with fast algorithms, allows for rapid reconfiguration of the traps. We demonstrate trapping of up to 20 atoms in arbitrary arrangements, and the transport of a single-atom over a distance of 14 μm with continuous laser cooling, and 5 μm without. In the meantime, we are developing high-finesse fibre-tip cavities, which we plan to use to couple pairs of single atoms to form a quantum network.

  4. Trap split with Laguerre-Gaussian beams

    CERN Document Server

    Kazemi, Seyedeh Hamideh; Mahmoud, Mohammad

    2016-01-01

    The optical trapping techniques have been extensively used in physics, biophysics, micro-chemistry, and micro-mechanics to allow trapping and manipulation of materials ranging from particles, cells, biological substances, and polymers to DNA and RNA molecules. In this Letter, we present a convenient and effective way to generate a novel phenomenon of trapping, named trap split, in a conventional four-level double-$\\Lambda$ atomic system driven by four femtosecond Laguerre-Gaussian laser pulses. We find that trap split can be always achieved when atoms are trapped by such laser pulses, as compared to Gaussian ones. This work would greatly facilitate the trapping and manipulating the particles and generation of trap split. It may also suggest the possibility of extension into new research fields, such as micro-machining and biophysics.

  5. Optical and Magnetic Trapping of Potassium 39

    Science.gov (United States)

    Ensher, Jason; Cornell, Eric; Cataliotti, Francesco; Fort, Chiara; Marin, Francesco; Prevedelli, Marco; Inguscio, Massimo; Ricci, Leonardo; Tino, Guglielmo

    1998-05-01

    We present measurments of optical trapping and cooling and magnetic trapping of ^39K in a double-MOT apparatus. (Optics Lett. 21, 290(1996)) We have measured light-assisted collisional loss rates from our second MOT over a range of trap light intensities. At an intensity of 10 mW/cm^2 we find a loss rate parameter β of 2 x 10-11 cc/s. β increases with trap light intensity and is consistent with the values measured by Williamson and Walker (JOSA B 12, 1393 (1995)). We also present studies of the temperature of atoms in a MOT of ^39K. Under certain conditions of repump light intensity and trap light detuning we measure temperatures nearly as low as the Doppler Limit. Finally, we report on prelimiary results of magnetic trapping in which we have trapped several 10^7 atoms in a quadrupole magnetic trap.

  6. Ion trap in a semiconductor chip

    Science.gov (United States)

    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.

  7. Ion Trap in a Semiconductor Chip

    CERN Document Server

    Stick, D; 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 ion. Work on miniaturizing electromagnetic traps to the micrometer 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 micrometer-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...

  8. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yukun; Gao Shutao; Zang Xiaohuan [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Li Jingci, E-mail: jingcili63@yahoo.com.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Ma Jingjun, E-mail: majingjun@hebau.edu.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer Graphene as a novel sorbent material in a column for solid-phase extraction (SPE). Black-Right-Pointing-Pointer SPE for the determination of lead (Pb) in environment water samples and vegetable samples. Black-Right-Pointing-Pointer The system can be reused for many times. Black-Right-Pointing-Pointer The adsorption capacity of graphene over many other adsorbents. Black-Right-Pointing-Pointer Graphene has great potentials as an excellent sorbent material. - Abstract: Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 {mu}g L{sup -1} with a detection limit of 0.61 {mu}g L{sup -1}. The relative standard deviation for ten replicate measurements of 20.0 and 400.0 {mu}g L{sup -1} of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes.

  9. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Capdevilla, C.

    1980-07-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

  10. Detection of Trapped Antihydrogen

    CERN Document Server

    Hydomako, Richard Allan

    The ALPHA experiment is an international effort to produce, trap, and perform precision spectroscopic measurements on antihydrogen (the bound state of a positron and an antiproton). Based at the Antiproton Decelerator (AD) facility at CERN, the ALPHA experiment has recently magnetically confined antihydrogen atoms for the first time. A crucial element in the observation of trapped antihydrogen is ALPHA’s silicon vertexing detector. This detector contains sixty silicon modules arranged in three concentric layers, and is able to determine the three-dimensional location of the annihilation of an antihydrogen atom by reconstructing the trajectories of the produced annihilation products. This dissertation focuses mainly on the methods used to reconstruct the annihilation location. Specifically, the software algorithms used to identify and extrapolate charged particle tracks are presented along with the routines used to estimate the annihilation location from the convergence of the identified tracks. It is shown...

  11. Characterization of a magnetic trap by polarization dependent Zeeman spectroscopy

    DEFF Research Database (Denmark)

    Nielsen, Carsten Vandel; Lyngsøe, Jens Kristian; Thorseth, Anders;

    2008-01-01

    This paper demonstrates a detailed experimental study of our cloverleaf magnetic trap for sodium atoms. By using polarization dependent Zeeman spectroscopy of our atomic beam, passing the magnetic trap region, we have determined important trap parameters such as gradients, their curvatures and...

  12. 亚微米局域空心光束的产生及其在单原子囚禁与冷却中的应用理论研究∗%Theoretical research on the generation of a submicron lo calized hollow b eam and its applications in the trapping and co oling of a single atom

    Institute of Scientific and Technical Information of China (English)

    任瑞敏; 尹亚玲; 王志章; 郭超修; 印建平

    2016-01-01

    In order to generate a submicron localized hollow laser beam and realize the more efficient laser cooling and trapping of a single atom, a simple and promising scheme with using the system of a single mode fiber a circle binary phase plate and a microlens is proposed in this paper. From Rayleigh-Sommerfeld diffraction theory, the intensity distribution of the generated localized hollow laser beam near the focal plane and its propagating properties in free space are calculated. Also, the dependences of the dark-spot size of the localized hollow beam on the mode radius of single mode fiber and the focal length of the mocrolens are studied. The calculated results show that the intensity distribution of the localized hollow beam presents approximately symmstrical distribution near the focal plane. In the center of the focal plane, the light intensity is 0 and increases gradually around it. So a closed spherical light field (i.e., localized hollow laser beam) with a radius of 0.4 µm is generated. The calculated results also show that the dark-spot size of the localized hollow laser beam decreases with the increasing of the microlens focal length and the decreasing of the single mode fiber mode radius. So proper parameters of this optical system can be chosen to generate localized hollow laser beams with different sizes for various applications. When the localized hollow laser beam is blue detuned, atoms will be trapped in the minimum light filed. If a repumping laser beam is applied, the trapped atoms will be also cooled by the intensity-gradient Sisyphus cooling. In this paper, we build a device for trapping and cooling a single atom by using the generated blue detuned submicron localized hollow laser beam. We study the dynamical process of intensity-gradient cooling of a single 87Rb atom trapped in the localized hollow beam by Monte-Carlo method. Our study shows that a single 87Rb atom with a temperature of 120 µK (the corresponding momentum is 30~k) from a magneto

  13. Atomic laser-beam finder.

    Science.gov (United States)

    Viering, Kirsten; Medellin, David; Mo, Jianyong; Raizen, Mark G

    2012-11-01

    We report on an experimental method to align a laser beam to a cloud of atoms trapped in a magneto-optical trap (MOT). We show how balanced lock-in detection leads to a very sensitive method to align the laser beam to the atoms in the plane perpendicular to the propagation direction. This provides a very reliable and fast way of aligning laser beams to atoms trapped in a MOT.

  14. Integrated magneto-optical traps on a chip

    OpenAIRE

    Pollock, S.; Cotter, J. P.; Laliotis, A.; Hinds, E. A.

    2009-01-01

    We have integrated magneto-optical traps (MOTs) into an atom chip by etching pyramids into a silicon wafer. These have been used to trap atoms on the chip, directly from a room temperature vapor of rubidium. This new atom trapping method provides a simple way to integrate several atom sources on the same chip. It represents a substantial advance in atom chip technology and offers new possibilities for atom chip applications such as integrated single atom or photon sources and molecules on a c...

  15. Determination of trace mercury in environmental and foods samples by online coupling of flow injection displacement sorption preconcentration to electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Li, Yan; Jiang, Yan; Yan, Xiu-Ping; Ni, Zhe-Ming

    2002-11-15

    The toxic effects of mercury are well-known. To establish sources of mercury contamination and to evaluate levels of mercury pollution, sensitive, selective, and accurate analytical methods with excellent reproducibility are required. We have developed a novel methodology for the determination of trace mercury in environmental and foods samples by online coupling of flow injection (FI) displacement sorption preconcentration in a knotted reactor (KR) to electrothermal atomic absorption spectrometry (ETAAS). The developed methodology involved the online formation of copper pyrrolidine dithiocarbamate (Cu-PDC), presorption of the resulting Cu-PDC onto the inner walls of the KR, and selective retention of the analyte Hg(ll) onto the inner walls of the KR through online displacement reaction between Hg(ll) and the presorbed Cu-PDC. The retained analyte was subsequently eluted by 50 microL of ethanol and online detected by ETAAS. Interferences from coexisting heavy metal ions with lower stability of their APDC complexes relative to Cu- PDC were minimized without the need of any masking reagents. The tolerable concentrations of Cu(II), Cd(II), Fe(III), Ni(III), and Zn(II) were up to 12, 20, 16, 20, and 60 mg L(-1), respectively. No additional chemical modifiers for the stabilization of mercury were required in the present system owing to the stability of Hg-PDC at the drying stage, and no pyrolysis stage was necessary due to the effective removal of the matrices. With consumption of 2.5 mL of sample solution, an enhancement factor of 91 was obtained in comparison with direct injection of 50 microL of aqueous solution. The relative detection limit (3s) was 6.2 ng L(-1), corresponding to an absolute detection limit of 15.5 pg. The precision (RSD, n = 13) was 1.1% at the 2 microg L(-1) level. The method was successfully applied to the determination of mercury in several certified environmental and foods reference materials and locally collected water samples. PMID:12487313

  16. Further study on a flow injection on-line multiplexed sorption preconcentration coupled with flame atomic absorption spectrometry for trace element determination.

    Science.gov (United States)

    Li, Yan; Jiang, Yan; Yan, Xiu-Ping

    2004-10-20

    A further study on a newly developed flow injection (FI) on-line multiplexed sorption preconcentration (MSP) using a knotted reactor coupled with flame atomic absorption spectrometry (FAAS) was carried out to demonstrate its applicability and limitation for trace element determination. For this purpose, Cr(VI), Cu(II), Ni(II) and Co(II) were selected as the analytes, and detailed comparison was made between the MSP-FAAS and conventional FI on-line sorption preconcentration FAAS in respect to retention efficiency and linear ranges of absorbance versus sample loading flow rate and total preconcentration time. Introduction of an air-flow for removal of the residual solution in the KR after each sub-injection in the MSP procedure played a decisive role in the improvement of retention efficiency. The linearity of absorbance versus sample loading flow rate or total preconcentration time was extended to a more degree for the metal ions with less stability of their PDC (pyrrolidine dithiocarbamate) complexes than those with more stable PDC complexes. It seems that the MSP procedure behaves advantages beyond the inflection points in the diagrams of absorbance versus total preconcentration time and sample loading flow rate obtained by conventional (a single continuous) preconcentration procedure. With a sample loading flow rate of 6.0mlmin(-1) and a total preconcentration time of 180s, the retention efficiencies were increased from 25, 46, 41 and 63% with a single continuous sorption preconcentration to 44, 78, 65 and 75% with a six sub-injection preconcentration procedure for Cr(VI), Co(II), Ni(II), and Cu(II), respectively. The detection limits were 0.40, 0.33, 0.31 and 0.26mugl(-1) for Cr(VI), Co(II), Ni(II), and Cu(II), respectively. The precision (R.S.D.) for eleven replicate determination of 2mugl(-1) Cr(VI), Co(II) and Ni(II), and 1mugl(-1) Cu(II), was 2.1, 4.1, 2.6 and 1.7%, respectively. PMID:18969669

  17. Active Stabilization of Ion Trap Radiofrequency Potentials

    CERN Document Server

    Johnson, K G; Neyenhuis, B; Mizrahi, J; Monroe, C

    2016-01-01

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a rf Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to better than 10 Hz, or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  18. Antihydrogen and mirror-trapped antiproton discrimination: Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap

    OpenAIRE

    Amole, C.; Andresen, G. B.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Butler, E.; Cesar, C. L.; S. Chapman; Charlton, M.; Deller, A.; Eriksson, S.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.

    2012-01-01

    Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected s...

  19. Direct frequency comb laser cooling and trapping

    CERN Document Server

    Jayich, A M; Campbell, W C

    2016-01-01

    Continuous wave (CW) lasers are the enabling technology for producing ultracold atoms and molecules through laser cooling and trapping. The resulting pristine samples of slow moving particles are the de facto starting point for both fundamental and applied science when a highly-controlled quantum system is required. Laser cooled atoms have recently led to major advances in quantum information, the search to understand dark energy, quantum chemistry, and quantum sensors. However, CW laser technology currently limits laser cooling and trapping to special types of elements that do not include highly abundant and chemically relevant atoms such as hydrogen, carbon, oxygen, and nitrogen. Here, we demonstrate that Doppler cooling and trapping by optical frequency combs may provide a route to trapped, ultracold atoms whose spectra are not amenable to CW lasers. We laser cool a gas of atoms by driving a two-photon transition with an optical frequency comb, an efficient process to which every comb tooth coherently cont...

  20. Solid phase extraction of ultra traces silver(I) using octadecyl silica membrane disks modified by 1,3-bis(2-cyanobenzene) triazene (CBT) ligand prior to determination by flame atomic absorption

    Energy Technology Data Exchange (ETDEWEB)

    Rofouei, Mohammad Kazem, E-mail: rofouei@tmu.ac.ir [Faculty of Chemistry, Tarbiat Moalem University, Tehran (Iran, Islamic Republic of); Payehghadr, Mahmood [Department of Chemistry, Payame Noor University (PNU) (Iran, Islamic Republic of); Shamsipur, Mojtaba [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Ahmadalinezhad, Asieh [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada)

    2009-09-15

    A simple, reliable and rapid method for preconcentration and determination of the ultra trace amount of silver using octadecyl silica membrane disk modified by a recently synthesized triazene ligand, 1,3-bis(2-cyanobenzene)triazene (CBT), and flame atomic absorption spectrometry is presented. Various parameters including pH of aqueous solution, flow rates, the amount of ligand and the type of stripping solvents were optimized. The breakthrough volume was greater than 1800 ml with an enrichment factor of more than 360 and 6.0 ng l{sup -1} detection limit. The capacity of the membrane disks modified by 5 mg of the ligand was found to be 1070 {mu}g of silver. The effects of various cationic interferences on the percent recovery of silver ion were studied. The method was successfully applied to the determination of silver ion in different samples, especially determination of ultra trace amount of silver in the presence of large amount of lead.