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Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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1

Electron source for a mini ion trap mass spectrometer  

DOE Patents (OSTI)

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

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

1995-12-19T23:59:59.000Z

2

ESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis of  

E-Print Network (OSTI)

discuss a new separation strategy for biomolecules that is based on differences in ion mobilitiesESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis* Department of Chemistry, Indiana University, Bloomington, Indiana 47405 An ion trap/ion mobility

Clemmer, David E.

3

Final Report - Advanced Ion Trap Mass Spectrometry Program - Oak Ridge National Laboratory - Sandia National Laboratory  

Science Conference Proceedings (OSTI)

This report covers the three main projects that collectively comprised the Advanced Ion Trap Mass Spectrometry Program. Chapter 1 describes the direct interrogation of individual particles by laser desorption within the ion trap mass spectrometer analyzer. The goals were (1) to develop an ''intelligent trigger'' capable of distinguishing particles of biological origin from those of nonbiological origin in the background and interferent particles and (2) to explore the capability for individual particle identification. Direct interrogation of particles by laser ablation and ion trap mass spectrometry was shown to have good promise for discriminating between particles of biological origin and those of nonbiological origin, although detailed protocols and operating conditions were not worked out. A library of more than 20,000 spectra of various types of biological particles has been assembled. Methods based on multivariate analysis and on neural networks were used to discriminate between particles of biological origin and those of nonbiological origin. It was possible to discriminate between at least some species of bacteria if mass spectra of several hundred similar particles were obtained. Chapter 2 addresses the development of a new ion trap mass analyzer geometry that offers the potential for a significant increase in ion storage capacity for a given set of analyzer operating conditions. This geometry may lead to the development of smaller, lower-power field-portable ion trap mass spectrometers while retaining laboratory-scale analytical performance. A novel ion trap mass spectrometer based on toroidal ion storage geometry has been developed. The analyzer geometry is based on the edge rotation of a quadrupolar ion trap cross section into the shape of a torus. Initial performance of this device was poor, however, due to the significant contribution of nonlinear fields introduced by the rotation of the symmetric ion-trapping geometry. These nonlinear resonances contributed to poor mass resolution and sensitivity and to erratic ion ejection behavior. To correct for these nonlinear effects, the geometry of the toroid ion trap analyzer has been modified to create an asymmetric torus, as first suggested by computer simulations that predicted significantly improved performance and unit mass resolution for this geometry. A reduced-sized version (one-fifth scale) has been fabricated but was not tested within the scope of this project. Chapter 3 describes groundbreaking progress toward the use of ion-ion chemistry to control the charge state of ions formed by the electrospray ionization process, which in turn enables precision analysis of whole proteins. In addition, this technique may offer the unique possibility of a priori identification of unknown biological material when employed with existing proteomics and genomic databases. Ion-ion chemistry within the ion trap was used to reduce the ions in highly charged states to states of +1 and +2 charges. Reduction in charge greatly simplifies identification of molecular weights of fragments from large biological molecules. This technique enables the analysis of whole proteins as biomarkers for the detection and identification of all three classes of biological weapons (bacteria, toxins, and viruses). In addition to methods development, tests were carried out with samples of tap water, local creek water, and soil (local red clay) spiked with melittin (bee venom), cholera toxin, and virus MS2. All three analytes were identified in tap water and soil; however, all three were problematic for detection in creek water at concentrations of 1 nM. More development of methods is needed.

Whitten, W.B.

2002-12-18T23:59:59.000Z

4

The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements  

Science Conference Proceedings (OSTI)

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

Simon, M. C.; Eberhardt, B.; Jang, F.; Luichtl, M.; Robertson, D.; Chaudhuri, A.; Delheij, P.; Grossheim, A.; Kwiatkowski, A. A.; Mane, E.; Pearson, M. R.; Schultz, B. E. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Bale, J. C. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Chowdhury, U. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Ettenauer, S.; Gallant, A. T.; Dilling, J. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Lennarz, A. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, D-48149 Muenster (Germany); Ma, T.; Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); and others

2012-02-15T23:59:59.000Z

5

Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions  

Science Conference Proceedings (OSTI)

We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure ({approx}10{sup -5} Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarily increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH{sup +}, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.

Gulyuz, Kerim; Stedwell, Corey N.; Wang Da; Polfer, Nick C. [Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611 (United States)

2011-05-15T23:59:59.000Z

6

Microfabricated Ion Traps  

E-Print Network (OSTI)

Ion traps offer the opportunity to study fundamental quantum systems with high level of accuracy highly decoupled from the environment. Individual atomic ions can be controlled and manipulated with electric fields, cooled to the ground state of motion with laser cooling and coherently manipulated using optical and microwave radiation. Microfabricated ion traps hold the advantage of allowing for smaller trap dimensions and better scalability towards large ion trap arrays also making them a vital ingredient for next generation quantum technologies. Here we provide an introduction into the principles and operation of microfabricated ion traps. We show an overview of material and electrical considerations which are vital for the design of such trap structures. We provide guidance in how to choose the appropriate fabrication design, consider different methods for the fabrication of microfabricated ion traps and discuss previously realized structures. We also discuss the phenomenon of anomalous heating of ions within ion traps, which becomes an important factor in the miniaturization of ion traps.

Marcus D. Hughes; Bjoern Lekitsch; Jiddu A. Broersma; Winfried K. Hensinger

2011-01-17T23:59:59.000Z

7

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

We fabricate superconducting ion traps with niobium and niobium nitride and trap single [superscript 88]Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the ...

Wang, Shannon Xuanyue

8

Ion trap simulation tools.  

Science Conference Proceedings (OSTI)

Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

Hamlet, Benjamin Roger

2009-02-01T23:59:59.000Z

9

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

Shannon X. Wang; Yufei Ge; Jaroslaw Labaziewicz; Eric Dauler; Karl Berggren; Isaac L. Chuang

2010-10-28T23:59:59.000Z

10

Microfabricated Ion Traps  

E-Print Network (OSTI)

Ion traps offer the opportunity to study fundamental quantum systems with high level of accuracy highly decoupled from the environment. Individual atomic ions can be controlled and manipulated with electric fields, cooled to the ground state of motion with laser cooling and coherently manipulated using optical and microwave radiation. Microfabricated ion traps hold the advantage of allowing for smaller trap dimensions and better scalability towards large ion trap arrays also making them a vital ingredient for next generation quantum technologies. Here we provide an introduction into the principles and operation of microfabricated ion traps. We show an overview of material and electrical considerations which are vital for the design of such trap structures. We provide guidance in how to choose the appropriate fabrication design, consider different methods for the fabrication of microfabricated ion traps and discuss previously realized structures. We also discuss the phenomenon of anomalous heating of ions with...

Hughes, Marcus D; Broersma, Jiddu A; Hensinger, Winfried K

2011-01-01T23:59:59.000Z

11

Interaction of trapped ions with trapped atoms  

E-Print Network (OSTI)

In this thesis, I present results from two Paul-trap based ion traps carried out in the Vuleti? laboratory: the Atom-Ion trap for collision studies between cold atoms and cold ions, and the Cavity-Array trap for studying ...

Grier, Andrew T. (Andrew Todd)

2011-01-01T23:59:59.000Z

12

Workshop on Ion Trap Technology  

Science Conference Proceedings (OSTI)

... optical components, conventional and microfabricated ion traps, and classical control ... will bring together experts on trapped-ion physics, laser optics ...

2011-03-01T23:59:59.000Z

13

Nonlinear integrable ion traps  

Science Conference Proceedings (OSTI)

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

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

2011-10-01T23:59:59.000Z

14

Asymmetric ion trap  

DOE Patents (OSTI)

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

Barlow, Stephan E. (Richland, WA); Alexander, Michael L. (Richland, WA); Follansbee, James C. (Pasco, WA)

1997-01-01T23:59:59.000Z

15

Ion Trap in a Semiconductor Chip  

E-Print Network (OSTI)

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 arsenide (GaAs) heterostructure.

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

2006-01-09T23:59:59.000Z

16

Laser Cooling of Trapped Ions.  

Science Conference Proceedings (OSTI)

... period, so it can be assumed to give an in- stantaneous impulse to the ... In sympathetic laser cooling, two different ion species are loaded into a trap. ...

2002-11-15T23:59:59.000Z

17

Ideal Multipole Ion Traps from Planar Ring Electrodes  

E-Print Network (OSTI)

We present designs for multipole ion traps based on a set of planar, annular, concentric electrodes which require only rf potentials to confine ions. We illustrate the desirable properties of the traps by considering a few simple cases of confined ions. We predict that mm-scale surface traps may have trap depths as high as tens of electron volts, or micromotion amplitudes in a 2-D ion crystal as low as tens of nanometers, when parameters of a magnitude common in the field are chosen. Several example traps are studied, and the scaling of those properties with voltage, frequency, and trap scale, for small numbers of ions, is derived. In addition, ions with very high charge-to-mass ratios may be confined in the trap, and species of very different charge-to-mass ratios may be simultaneously confined. Applications of these traps include quantum information science, frequency metrology, and cold ion-atom collisions.

Robert J. Clark

2012-07-25T23:59:59.000Z

18

Instrumentation development for coupling ion/ion reactions and ion mobility in biological mass spectrometry.  

E-Print Network (OSTI)

??The development of mass spectrometry (MS) instrumentation for novel biological applications, specifically, the development of instrumentation that integrates ion/ion reaction capabilities in an ion trap… (more)

Soyk, Matthew William

2008-01-01T23:59:59.000Z

19

Theory and application of planar ion traps  

E-Print Network (OSTI)

In this thesis, we investigate a new geometry of Paul trap with electrodes in a plane. These planar ion traps are compatible with modern silicon microfabrication, and can be scaled up to large arrays with multiple trapping ...

Pearson, Christopher Elliott

2006-01-01T23:59:59.000Z

20

Transparent ion trap with integrated photodetector  

E-Print Network (OSTI)

Fluorescence collection sets the efficiency of state detection and the rate of entanglement generation between remote trapped ion qubits. Despite efforts to improve light collection using various optical elements, solid angle capture is limited to ~10% for implementations that are scalable to many ions. We present an approach based on fluorescence detection through a transparent trap using an integrated photodetector, combining collection efficiency approaching 50% with scalability. We microfabricate transparent surface traps with indium tin oxide and verify stable trapping of single ions. The fluorescence from a cloud of ions is detected using a photodiode sandwiched with a transparent trap.

Amira M. Eltony; Shannon X. Wang; Gleb M. Akselrod; Peter F. Herskind; Isaac L. Chuang

2012-12-06T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Transparent ion trap with integrated photodetector  

E-Print Network (OSTI)

Fluorescence collection sets the efficiency of state detection and the rate of entanglement generation between remote trapped ion qubits. Despite efforts to improve light collection using various optical elements, solid angle capture is limited to ~10% for implementations that are scalable to many ions. We present an approach based on fluorescence detection through a transparent trap using an integrated photodetector, combining collection efficiency approaching 50% with scalability. We microfabricate transparent surface traps with indium tin oxide and verify stable trapping of single ions. The fluorescence from a cloud of ions is detected using a photodiode sandwiched with a transparent trap.

Eltony, Amira M; Akselrod, Gleb M; Herskind, Peter F; Chuang, Isaac L

2012-01-01T23:59:59.000Z

22

Study of Ion Cooling and Ejection from Two Stage Linear Quadrupole Ion Trap consisted of RFQ ion guides  

NLE Websites -- All DOE Office Websites (Extended Search)

Ion Cooling and Ejection from Two Stage Linear Quadrupole Ion Trap consisted of RFQ ion guides Ion Cooling and Ejection from Two Stage Linear Quadrupole Ion Trap consisted of RFQ ion guides Kozlovskiy V.I., Filatov V. V., Shchepunov (UNIRIB, O.R.A.U. Oak Ridge, TN, USA) V. A., Brusov V. S., Pikhtelev A. R., Zelenov V. V. Introduction The primary objective of this work concerns linear quadrupole ion traps, which are commonly used to interface a continuous ion beam from an external source with a mass analyzer, requiring bunched or pulsed beams. We assume that the ions prepared for mass analysis, are well spatially shaped, and normalized by ion kinetic energy. (Slava, I don't understand the meaning of the previous sentence - I wrote it as I interpreted what you are saying - I may be all wrong) In our work, such a device was developed and built to interface a source of continuous ion beams and a

23

Controlled Kinetic Energy Ion Source for Miniature Ion Trap ...  

with electronic signal sources coupled to the electrodes. The ion trap can be machined with conventional materials and methods and has demonstrated

24

Trapped Ions and Laser Cooling 11  

Science Conference Proceedings (OSTI)

... 2 GHz I ... monic well, eg, the absorption spectrum for the secular motion in an rf trap ... a sin- gle atom [mass of 100 u (atomic mass units)] starts from rest ...

2002-08-07T23:59:59.000Z

25

Modular cryostat for ion trapping with surface-electrode ion traps  

E-Print Network (OSTI)

We present a simple cryostat purpose built for use with surface-electrode ion traps, designed around an affordable, large cooling power commercial pulse tube refrigerator. A modular vacuum enclosure with a single vacuum space facilitates interior access, and enables rapid turnaround and flexiblity for future modifications. Long rectangular windows provide nearly 360 degrees of optical access in the plane of the ion trap, while a circular bottom window near the trap enables NA 0.4 light collection without the need for in-vacuum optics. We evaluate the system's mechanical and thermal characteristics, and we quantify ion trapping performance by trapping 40Ca+, finding small stray electric fields, long ion lifetimes, and low ion heating rates.

Grahame Vittorini; Kenneth Wright; Kenneth R. Brown; Alexa W. Harter; S. Charles Doret

2013-02-20T23:59:59.000Z

26

NIST Racetrack Ion Trap is a Contender in Quantum ...  

Science Conference Proceedings (OSTI)

... ion trap under development as possible hardware for a future quantum computer. ... loading of 10 magnesium ions at once and transport of an ion ...

2011-10-26T23:59:59.000Z

27

Controlling trapping and ejection of ions from multipole ...  

Controlling trapping and ejection of ions from multipole guides and traps ... The concept can be used to control the kinetic energy of the

28

Two-dimensional ion trap lattice on a microchip  

E-Print Network (OSTI)

Microfabricated ion traps are a major advancement towards scalable quantum computing with trapped ions. The development of more flexible ion trap designs, in which tailored arrays of ions are positioned in two dimensions above a microfabricated surface, would lead to applications in fields as varied as quantum simulation, metrology and atom-ion interactions. Current surface ion traps often have low trap depths and high heating rates, due to the size of the voltages that can be applied to them, limiting the fidelity of quantum gates. In this article we report on a fabrication process that allows for the application of very high voltages to microfabricated devices in general and we apply this advance to fabricate a 2D ion trap lattice on a microchip. Our scalable microfabricated architecture allows for reliable trapping of 2D ion lattices, long ion lifetimes due to the deep trapping potential, rudimentary shuttling between lattice sites and the ability to deterministically introduce defects into the ion lattice.

R. C. Sterling; H. Rattanasonti; S. Weidt; K. Lake; P. Srinivasan; S. C. Webster; M. Kraft; W. K. Hensinger

2013-02-15T23:59:59.000Z

29

Towards a cryogenic planar ion trap for Sr-88  

E-Print Network (OSTI)

This thesis describes experiments with ion traps constructed with electrodes in a single two-dimensional plane, and ion traps operated in a cryogenic environment at 77K and 4K temperatures. These two technologies address ...

Bakr, Waseem (Waseem S.)

2006-01-01T23:59:59.000Z

30

A quantum information processor with trapped ions  

E-Print Network (OSTI)

Quantum computers hold the promise to solve certain problems exponentially faster than their classical counterparts. Trapped atomic ions are among the physical systems in which building such a computing device seems viable. In this work we present a small-scale quantum information processor based on a string of $^{40}$Ca${^+}$ ions confined in a macroscopic linear Paul trap. We review our set of operations which includes non-coherent operations allowing us to realize arbitrary Markovian processes. In order to build a larger quantum information processor it is mandatory to reduce the error rate of the available operations which is only possible if the physics of the noise processes is well understood. We identify the dominant noise sources in our system and discuss their effects on different algorithms. Finally we demonstrate how our entire set of operations can be used to facilitate the implementation of algorithms by examples of the quantum Fourier transform and the quantum order finding algorithm.

Philipp Schindler; Daniel Nigg; Thomas Monz; Julio T. Barreiro; Esteban Martinez; Shannon X. Wang; Stephan Quint; Matthias F. Brandl; Volckmar Nebendahl; Christian F. Roos; Michael Chwalla; Markus Hennrich; Rainer Blatt

2013-08-14T23:59:59.000Z

31

Iterated dynamical maps in an ion trap  

E-Print Network (OSTI)

Iterated dynamical maps offer an ideal setting to investigate quantum dynamical bifurcations and are well adapted to few-qubit quantum computer realisations. We show that a single trapped ion, subject to periodic impulsive forces, exhibits a rich structure of dynamical bifurcations derived from the Jahn-Teller Hamiltonian flow model. We show that the entanglement between the oscillator and electronic degrees of freedom reflects the underlying dynamical bifurcation in a Floquet eigenstate.

M. Duncan; J. Links; G. J. Milburn

2007-11-16T23:59:59.000Z

32

Universal digital quantum simulation with trapped ions  

E-Print Network (OSTI)

A digital quantum simulator is an envisioned quantum device that can be pro- grammed to efficiently simulate any other local system. We demonstrate and investigate the digital approach to quantum simulation in a system of trapped ions. Using sequences of up to 100 gates and 6 qubits, the full time dynamics of a range of spin systems are digitally simulated. Interactions beyond those naturally present in our simulator are accurately reproduced and quantitative bounds are provided for the overall simulation quality. Our results demon- strate the key principles of digital quantum simulation and provide evidence that the level of control required for a full-scale device is within reach.

B. P. Lanyon; C. Hempel; D. Nigg; M. Müller; R. Gerritsma; F. Zähringer; P. Schindler; J. T. Barreiro; M. Rambach; G. Kirchmair; M. Hennrich; P. Zoller; R. Blatt; C. F. Roos

2011-09-07T23:59:59.000Z

33

`Trapped' Ions Provide First View of Light Property  

Science Conference Proceedings (OSTI)

... PHYSICS `Trapped' Ions Provide First View of Light Property. ... Quantum theory states that light can act either as a wave or as a particle. ...

34

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

E-Print Network (OSTI)

Recent advances in quantum information processing with trapped ions have demonstrated the need for new ion trap architectures capable of holding and manipulating chains of many (>10) ions. Here we present the design and detailed characterization of a new linear trap, microfabricated with scalable complementary metal-oxide-semiconductor (CMOS) techniques, that is well-suited to this challenge. Forty-four individually controlled DC electrodes provide the many degrees of freedom required to construct anharmonic potential wells, shuttle ions, merge and split ion chains, precisely tune secular mode frequencies, and adjust the orientation of trap axes. Microfabricated capacitors on DC electrodes suppress radio-frequency pickup and excess micromotion, while a top-level ground layer simplifies modeling of electric fields and protects trap structures underneath. A localized aperture in the substrate provides access to the trapping region from an oven below, permitting deterministic loading of particular isotopic/elemental sequences via species-selective photoionization. The shapes of the aperture and radio-frequency electrodes are optimized to minimize perturbation of the trapping pseudopotential. Laboratory experiments verify simulated potentials and characterize trapping lifetimes, stray electric fields, and ion heating rates, while measurement and cancellation of spatially-varying stray electric fields permits the formation of nearly-equally spaced ion chains.

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

2012-04-18T23:59:59.000Z

35

Measurements of electric field noise and light-induced charging in cryogenic surface electrode ion traps  

E-Print Network (OSTI)

Ion traps provide an excellent tool for controlling and observing the state of a single trapped ion. For this reason, ion traps have been proposed as a possible system for large-scale quantum computation. However, many ...

Lachenmyer, Nathan S. (Nathan Scott)

2010-01-01T23:59:59.000Z

36

Cooling the Collective Motion of Trapped Ions to Initialize a Quantum Register  

E-Print Network (OSTI)

We report preparation in the ground state of collective modes of motion of two trapped 9Be+ ions. This is a crucial step towards realizing quantum logic gates which can entangle the ions' internal electronic states. We find that heating of the modes of relative ion motion is substantially suppressed relative to that of the center-of-mass modes, suggesting the importance of these modes in future experiments.

B. E. King; C. S. Wood; C. J. Myatt; Q. A. Turchette; D. Leibfried; W. M. Itano; C. Monroe; D. J. Wineland

1998-03-11T23:59:59.000Z

37

From transistor to trapped-ion computers for quantum chemistry  

E-Print Network (OSTI)

Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.

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

2013-07-16T23:59:59.000Z

38

Trapped Ion Imaging with a High Numerical Aperture Spherical Mirror  

E-Print Network (OSTI)

Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.

G Shu; M R Dietrich; N Kurz; B B Blinov

2009-01-29T23:59:59.000Z

39

Trapped Ion Imaging with a High Numerical Aperture Spherical Mirror  

E-Print Network (OSTI)

Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.

Shu, G; Kurz, N; Blinov, B B

2009-01-01T23:59:59.000Z

40

Quantum gates, sensors, and systems with trapped ions  

E-Print Network (OSTI)

Quantum information science promises a host of new and useful applications in communication, simulation, and computational algorithms. Trapped atomic ions are one of the leading physical systems with potential to implement ...

Wang, Shannon Xuanyue

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Ion Trapping for Ion Mobility Spectrometry Measurements in a Cyclical Drift Tube  

E-Print Network (OSTI)

us to consider new types of mobility measurements. In traditional IMS instruments, R scales as (ELIon Trapping for Ion Mobility Spectrometry Measurements in a Cyclical Drift Tube Rebecca S. Glaskin 47405, United States ABSTRACT: A new ion trapping technique, involving the accumulation of ions

Clemmer, David E.

42

Demonstration of a scalable, multiplexed ion trap for quantum information processing  

Science Conference Proceedings (OSTI)

A scalable, multiplexed ion trap for quantum information processing is fabricated and tested. The trap design and fabrication process are optimized for scalability to small trap size and large numbers of interconnected traps, and for integration of control ...

D. R. Leibrandt; J. Labaziewicz; R. J. Clark; I. L. Chuang; R. J. Epstein; C. Ospelkaus; J. H. Wesenberg; J. J. Bollinger; D. Leibfried; D. J. Wineland; D. Stick; J. Sterk; C. Monroe; C.-S. Pai; Y. Low; R. Frahm; R. E. Slusher

2009-11-01T23:59:59.000Z

43

Microfabrication techniques for trapped ion quantum ...  

Science Conference Proceedings (OSTI)

... used for micro-traps, starting with stacking multiple wafers to form a ... dc rf dc rf dc ... This section starts with a description of the tried and true gold-on ...

2010-07-21T23:59:59.000Z

44

Structural Transitions of Electrosprayed Ubiquitin Ions Stored in an Ion Trap over 10 ms Sunnie Myung, Ethan R. Badman, Young Jin Lee, and David E. Clemmer*  

E-Print Network (OSTI)

phase by a new ion trap/ion mobility-mass spectrometry technique. The approach allows transitions ms time scales of previous mobility measurements [J. Am. Soc. Mass Spectrom. 1997, 8, 954] and minute these conformers as they evolve from states that are formed initially by ESI into new gas-phase structures over

Clemmer, David E.

45

Heating of trapped ions from the quantum ground state  

E-Print Network (OSTI)

We have investigated motional heating of laser-cooled 9Be+ ions held in radio-frequency (Paul) traps. We have measured heating rates in a variety of traps with different geometries, electrode materials, and characteristic sizes. The results show that heating is due to electric-field noise from the trap electrodes which exerts a stochastic fluctuating force on the ion. The scaling of the heating rate with trap size is much stronger than that expected from a spatially uniform noise source on the electrodes (such as Johnson noise from external circuits), indicating that a microscopic uncorrelated noise source on the electrodes (such as fluctuating patch-potential fields) is a more likely candidate for the source of heating.

Q. A. Turchette; D. Kielpinski; B. E. King; D. Leibfried; D. M. Meekhof; C. J. Myatt; M. A. Rowe; C. A. Sackett; C. S. Wood; W. M. Itano; C. Monroe; D. J. Wineland

2000-02-14T23:59:59.000Z

46

Electron Beam Ion Trap (EBIT) Facility  

Science Conference Proceedings (OSTI)

... At these temperatures, even the heaviest atoms shed most of their electrons. ... The ions are probed with an intense electron beam, and the emitted ...

2013-06-06T23:59:59.000Z

47

Storing Electrons Instead of Positrons Without Trapping of Positive Ions  

NLE Websites -- All DOE Office Websites (Extended Search)

Electrons Instead of Positrons Without Electrons Instead of Positrons Without Trapping of Positive Ions LS-75 T. K. Khoe October, 1986 In this note, a procedure to inject and store electrons in the ring without trapping ions will be described. The minimum injection current per bunch below which ion trapping occur will be determined. Since the vertical beam size is smaller than the horizontal beam size, we will consider the vertical motion only. The following assumptions are made: 1. The bunch period is much longer than the bunch length. This assumption allow us to use the thin lens approximation for the focusing effect of the electron bunch. 2. The bunch length is much larger than the transverse dimensions of the beam. A two-dimensional calculation can then be used to obtain the

48

Heating of trapped ions from the quantum ground state  

E-Print Network (OSTI)

We have investigated motional heating of laser-cooled 9Be+ ions held inradio-frequency (Paul) traps. We have measured heating rates in a variety oftraps with different geometries, electrode materials, and characteristic sizes.The results show that heating is due to electric-field noise from the trapelectrodes which exerts a stochastic fluctuating force on the ion. The scalingof the heating rate with trap size is much stronger than that expected from aspatially uniform noise source on the electrodes (such as Johnson noise fromexternal circuits), indicating that a microscopic uncorrelated noise source onthe electrodes (such as fluctuating patch-potential fields) is a more likelycandidate for the source of heating.

Turchette, Q A; King, B E; Leibfried, D; Meekhof, D M; Myatt, C J; Rowe, M A; Sackett, C A; Wood, C S; Itano, W M; Monroe, C; Wineland, D J

2000-01-01T23:59:59.000Z

49

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

SciTech Connect

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

Knapp, D.

1994-11-02T23:59:59.000Z

50

Photoionizing Trapped Highly Charged Ions with Synchrotron Radiation  

SciTech Connect

Photoabsorption by highly charged ions plays an essential role in astrophysical plasmas. Diagnostics of photoionized plasmas surrounding binary systems rely heavily on precise identification of absorption lines and on the knowledge of their cross sections and widths. Novel experiments using an electron beam ion trap, FLASH EBIT, in combination with monochromatic synchrotron radiation allow us to investigate ions in charge states hitherto out of reach. Trapped ions can be prepared in any charge state at target densities sufficient to measure absorption cross sections below 0.1 Mb. The results benchmark state-of-the-art predictions of the transitions wavelengths, widths, and absolute cross sections. Recent high resolution results on Fe{sup 14+}, Fe{sup 15+}, and Ar{sup 12+} at photon energies up to 1 keV are presented.

Crespo, J R; Simon, M; Beilmann, C; Rudolph, J; Steinbruegge, R; Eberle, S; Schwarz, M; Baumann, T; Schmitt, B; Brunner, F; Ginzel, R; Klawitter, R; Kubicek, K; Epp, S; Mokler, P; Maeckel, V; Ullrich, J; Brown, G V; Graf, A; Leutenegger, M; Beiersdorfer, P; Behar, E; Follath, R; Reichardt, G; Schwarzkopf, O

2011-09-12T23:59:59.000Z

51

Laser induced fluorescence of trapped molecular ions  

SciTech Connect

Laser induced fluoresence (LIF) spectra (laser excitation spectra) are conceptually among the most simple spectra to obtain. One need only confine a gaseous sample in a suitable container, direct a laser along one axis of the container, and monitor the sample's fluorescence at a right angle to the laser beam. As the laser wavelength is changed, the changes in fluorescence intensity map the absorption spectrum of the sample. (More precisely, only absorption to states which have a significant radiative decay component are monitored.) For ion spectroscopy, one could benefit in many ways by such an experiment. Most optical ion spectra have been observed by emission techniques, and, aside from the problems of spectral analysis, discharge emission methods often produce the spectra of many species, some of which may be unknown or uncertain. Implicit in the description of LIF given above is certainty as to the chemical identity of the carrier of the spectrum. This article describes a method by which the simplifying aspects of LIF can be extended to molecular ions (albeit with a considerable increase in experimental complexity over that necessary for stable neutral molecules).

Winn, J.S.

1980-10-01T23:59:59.000Z

52

Quantum Energy Teleportation with Trapped Ions  

E-Print Network (OSTI)

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

Masahiro Hotta

2009-08-20T23:59:59.000Z

53

Finite-geometry models of electric field noise from patch potentials in ion traps  

E-Print Network (OSTI)

We model electric field noise from fluctuating patch potentials on conducting surfaces by taking into account the finite geometry of the ion trap electrodes to gain insight into the origin of anomalous heating in ion traps. ...

Low, Guang Hao

54

Microfabricated surface ion trap on a high-finesse optical mirror  

E-Print Network (OSTI)

A novel approach to optics integration in ion traps is demonstrated based on a surface electrode ion trap that is microfabricated on top of a dielectric mirror. Additional optical losses due to fabrication are found to be ...

Herskind, Peter F.

55

First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap  

SciTech Connect

Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

Ettenauer, S.; Gallant, A. T.; Dilling, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Brunner, T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Physik Department E12, Technische Universitaet Muenchen, D-85748 Garching (Germany); Chowdhury, U. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Simon, V. V. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Ruprecht-Karls-Universitaet, Heidelberg (Germany); Brodeur, M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Audi, G. [CSNSM-IN2P3-CNRS, Universite Paris 11, 91405 Orsay (France); Lopez-Urrutia, J. R. Crespo; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Gwinner, G. [Dept. of Physics and Astronomy, Univ. of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Lapierre, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); National Superconducting Cyclotron Lab., Michigan State Univ., East Lansing, Michigan 48824 (United States); Lunney, D. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); CSNSM-IN2P3-CNRS, Univ. Paris 11, 91405 Orsay (France); Ringle, R. [National Superconducting Cyclotron Lab., Michigan State Univ., East Lansing, Michigan 48824 (United States)

2011-12-30T23:59:59.000Z

56

The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results  

E-Print Network (OSTI)

The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for different excitation times, pulse structures, and detunings of the quadrupole field has been carried out in a quantum mechanical framework and is discussed in detail in the preceding article in this journal by M. Kretzschmar. Here, the new excitation technique has been applied with the ISOLTRAP mass spectrometer at ISOLDE/CERN for mass measurements on stable as well as short-lived nuclides. The experimental resonances are in agreement with the theoretical predictions and a precision gain close to a factor of four was achieved compared to the use of the conventional excitation technique.

S. George; K. Blaum; F. Herfurth; A. Herlert; M. Kretzschmar; S. Nagy; S. Schwarz; L. Schweikhard; C. Yazidjian

2007-01-22T23:59:59.000Z

57

Nuclear spin qubits in a trapped-ion quantum computer  

E-Print Network (OSTI)

Physical systems must fulfill a number of conditions to qualify as useful quantum bits (qubits) for quantum information processing, including ease of manipulation, long decoherence times, and high fidelity readout operations. Since these conditions are hard to satisfy with a single system, it may be necessary to combine different degrees of freedom. Here we discuss a possible system, based on electronic and nuclear spin degrees of freedom in trapped ions. The nuclear spin yields long decoherence times, while the electronic spin, in a magnetic field gradient, provides efficient manipulation, and the optical transitions of the ions assure a selective and efficient initialization and readout.

M. Feng; Y. Y. Xu; F. Zhou; D. Suter

2009-04-26T23:59:59.000Z

58

All-optical ion generation for ion trap loading  

E-Print Network (OSTI)

We have investigated the all-optical generation of ions by photo-ionisation of atoms generated by pulsed laser ablation. A direct comparison between a resistively heated oven source and pulsed laser ablation is reported. Pulsed laser ablation with 10 ns Nd:YAG laser pulses is shown to produce large calcium flux, corresponding to atomic beams produced with oven temperatures greater than 650 K. For an equivalent atomic flux, pulsed laser ablation is shown to produce a thermal load more than one order of magnitude smaller than the oven source. The atomic beam distributions obey Maxwell-Boltzmann statistics with most probable speeds corresponding to temperatures greater than 2200 K. Below a threshold pulse fluence between 280 mJ/cm^2 and 330 mJ/cm^2, the atomic beam is composed exclusively of ground state atoms. For higher fluences ions and excited atoms are generated.

Sheridan, Kevin; Keller, Matthias

2011-01-01T23:59:59.000Z

59

Design of superconducting transmission line integrated surface-electrode ion-traps  

E-Print Network (OSTI)

We fabricated superconducting surface electrode ion traps with integrated microwave coplanar waveguides using direct-write optical lithography and a niobium on sapphire process. We then tested these traps in a closed cycle ...

Meyer, David Thomas

2011-01-01T23:59:59.000Z

60

Anti-hydrogen production with positron beam ion trap  

Science Conference Proceedings (OSTI)

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

Itahashi, Takahisa [Department of Physics, Graduate School of Science, Osaka University 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan)

2008-08-08T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Selective control of the symmetric Dicke subspace in trapped ions  

SciTech Connect

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

Lopez, C. E.; Retamal, J. C. [Departamento de Fisica, Universidad de Santiago de Chile, Casilla 307 Correo 2, Santiago (Chile); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2007-09-15T23:59:59.000Z

62

Selective interactions in trapped ions: State reconstruction and quantum logic  

SciTech Connect

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

Solano, E. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany and Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2005-01-01T23:59:59.000Z

63

High intensity electron beam ion trap for charge state boosting of radioactive ion beams  

SciTech Connect

A high intensity electron beam ion trap under development at LLNL could be adapted for charge state boosting of radioactive ion beams, enabling a substantial reduction in the size and cost of a post-accelerator. We report estimates of the acceptance, ionization time, charge state distribution, emittance, and beam intensity for charge state boosting of radioactive ions in this device. The estimates imply that, for tin isotopes, over 10{sup 10} ions/s can be ionized to q = 40+ with an absolute emittance of approximately 1 (pi) mm mrad at an energy of 30 x q.k.

Marrs, R.

1998-09-30T23:59:59.000Z

64

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

Science Conference Proceedings (OSTI)

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

Pikin, A.; Kponou, A.; Alessi, J. G.; Beebe, E. N.; Prelec, K.; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

2008-02-15T23:59:59.000Z

65

Reliable transport through a microfabricated X-junction surface-electrode ion trap  

E-Print Network (OSTI)

We report the design, fabrication, and characterization of a microfabricated surface-electrode ion trap that supports controlled transport through the two-dimensional intersection of linear trapping zones arranged in a ninety-degree cross. The trap is fabricated with very-large-scalable-integration (VLSI) techniques which are compatible with scaling to a larger quantum information processor. The shape of the radio-frequency (RF) electrodes is optimized with a genetic algorithm to minimize axial pseudopotential barriers and to minimize ion heating during transport. Seventy-eight independent DC control electrodes enable fine control of the trapping potentials. We demonstrate reliable ion transport between junction legs, trapping of ion chains with nearly-equal spacing in one of the trap's linear sections, and merging and splitting ions from these chains. Doppler-cooled ions survive more than 10^5 round-trip transits between junction legs without loss and more than sixty-five consecutive round trips without laser cooling.

Kenneth Wright; Jason M. Amini; Daniel L. Faircloth; Curtis Volin; S. Charles Doret; Harley Hayden; C. -S. Pai; David W. Landgren; Douglas Denison; Tyler Killian; Richart E. Slusher; Alexa W. Harter

2012-10-12T23:59:59.000Z

66

Highly charged ions in Penning traps, a new tool for resolving low lying isomeric states  

E-Print Network (OSTI)

The use of highly charged ions increases the precision and resolving power, in particular for short-lived species produced at on-line radio-isotope beam facilities, achievable with Penning trap mass spectrometers. This increase in resolving power provides a new and unique access to resolving low-lying long-lived ($T_{1/2} > 50$ ms) nuclear isomers. Recently, the $111.19(22)$ keV (determined from $\\gamma$-ray spectroscopy) isomeric state in $^{78}$Rb has been resolved from the ground state, in a charge state of $q=8+$ with the TITAN Penning trap at the TRIUMF-ISAC facility. The excitation energy of the isomer was measured to be $108.7(6.4)$ keV above the ground state. The extracted masses for both the ground and isomeric states, and their difference, agree with the AME2003 and Nuclear Data Sheet values. This proof of principle measurement demonstrates the feasibility of using Penning trap mass spectrometers coupled to charge breeders to study nuclear isomers and opens a new route for isomer searches.

A. T. Gallant; M. Brodeur; T. Brunner; U. Chowdhury; S. Ettenauer; V. V. Simon; E. Mané; M. C. Simon; C. Andreoiu; P. Delheij; G. Gwinner; M. R. Pearson; R. Ringle; J. Dilling

2011-12-03T23:59:59.000Z

67

Status of Trapped-Ion Physics in Europe  

Science Conference Proceedings (OSTI)

... Innsbruck molecular ions spectroscopy K. Wendt Mainz heavy ions laser ion sources ... K. Wendt Mainz heavy ions laser ion sources W. Quint ...

2011-03-01T23:59:59.000Z

68

Generation of continuous variable squeezing and entanglement of trapped ions in time-varying potentials  

Science Conference Proceedings (OSTI)

We investigate the generation of squeezing and entanglement for the motional degrees of freedom of ions in linear traps, confined by time-varying and oscillating potentials, comprised of a DC and an AC component. We show that high degrees of squeezing ... Keywords: 03.67.Bg, 05.45.Xt, 37.10.Vz, 42.50.Dv, Control, Entanglement, Ion traps

Alessio Serafini; Alex Retzker; Martin B. Plenio

2009-12-01T23:59:59.000Z

69

Transport of Trapped-Ion Qubits within a Scalable Quantum ...  

Science Conference Proceedings (OSTI)

... 158 6.13 Glass vacuum envelope. . . . . ... 159 6.14 Picture of the trap inside of the glass envelope. . . . . ...

2010-12-03T23:59:59.000Z

70

Temperature-Driven Structural Phase Transition for Trapped Ions and a Proposal for its Experimental Detection  

SciTech Connect

A Wigner crystal formed with trapped ions can undergo a structural phase transition, which is determined only by the mechanical conditions on a classical level. Instead of this classical result, we show that through consideration of quantum and thermal fluctuation, a structural phase transition can be driven solely by a change in the system's temperature. We determine a finite-temperature phase diagram for trapped ions using the renormalization group method and the path integral formalism, and propose an experimental scheme to observe the predicted temperature-driven structural phase transition, which is well within the reach of the current ion trap technology.

Gong Zhexuan; Lin, G.-D.; Duan, L.-M. [Department of Physics and MCTP, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2010-12-31T23:59:59.000Z

71

Radial transport of energetic ions in the presence of trapped electron mode turbulence  

Science Conference Proceedings (OSTI)

The nature of transport of hot ions is studied in the presence of microturbulence generated by the trapped electron mode in a Tokamak using massively parallel, first principle based global nonlinear gyrokinetic simulation, and with the help of a passive tracer method. Passing and trapped hot ions are observed to exhibit inverse and inverse square scaling with energy, while those with isotropic pitch distribution are found to exhibit inverse dependence on energy. For all types of hot ions, namely, isotropic, passing, and trapped, the radial transport appears to be subdiffusive for the parameters considered.

Chowdhury, J.; Wang, W.; Ethier, S.; Manickam, J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2011-11-15T23:59:59.000Z

72

Secondary ion coincidence in highly charged ion based secondary ion mass spectroscopy for process characterization  

SciTech Connect

Coincidence counting in highly charged ion based secondary ion mass spectroscopy has been applied to the characterization of selective tungsten deposition via disilane reduction of tungsten hexafluoride on a patterned SiO{sub 2}/Si wafer. The high secondary ion yield and the secondary ion emission from a small area produced by highly charged ions make the coincidence technique very powerful.

Hamza, A.V.; Schenkel, T.; Barnes, A.V.; Schneider, D.H. [Lawrence Livermore National Laboratory, University of California, Livermore, California, 94551 (United States)] [Lawrence Livermore National Laboratory, University of California, Livermore, California, 94551 (United States)

1999-01-01T23:59:59.000Z

73

A Novel Method for Fundamental Interaction Studies with Electrostatic Ion Beam Trap  

E-Print Network (OSTI)

Trapped radioactive atoms present exciting opportunities for the study of fundamental interactions and symmetries. For example, detecting beta decay in a trap can probe the minute experimental signal that originates from possible tensor or scalar terms in the weak interaction. Such scalar or tensor terms affect, e.g., the angular correlation between a neutrino and an electron in the beta-decay process, thus probing new physics of "beyond-the-standard-model" nature. In particular, this article focuses on a novel use of an innovative ion trapping device, the Electrostatic Ion Beam Trap (EIBT). Such a trap has not been previously considered for Fundamental Interaction studies and exhibits potentially very significant advantages over other schemes. These advantages include improved injection efficiency of the radionuclide under study, an extended field-free region, ion-beam kinematics for better efficiency and ease-of-operation and the potential for a much larger solid angle for the electron and recoiling atom counters.

S. Vaintraub; M. Hass; O. Aviv; O. Heber; I. Mardor

2010-05-22T23:59:59.000Z

74

Loading of a surface-electrode ion trap from a remote, precooled source  

E-Print Network (OSTI)

We demonstrate loading of ions into a surface-electrode trap (SET) from a remote, laser-cooled source of neutral atoms. We first cool and load ?10[superscript 6] neutral [superscript 88]Sr atoms into a magneto-optical trap ...

Sage, Jeremy M.

75

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

Siverns, J D; Weidt, S; Hensinger, W K

2011-01-01T23:59:59.000Z

76

An optical-fiber interface to a trapped-ion quantum computer  

E-Print Network (OSTI)

The trapped-ion quantum computer is an atom-based implementation of a quantum computer that has successfully demonstrated numerous quantum algorithms and the potential for scalability. Fundamental to its operation is the ...

Kim, Tony Hyun

2011-01-01T23:59:59.000Z

77

Depletion, quantum jumps, and temperature measurements of ??Sr? ions in a linear Paul Trap  

E-Print Network (OSTI)

This thesis describes the design and construction of two laser systems to probe the 674nm transition of ??Sr? ions in a linear Paul trap. The first laser system made use of a molecular transition in Iodine to stabilize the ...

Richerme, Philip J

2006-01-01T23:59:59.000Z

78

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

J. D. Siverns; L. R. Simkins; S. Weidt; W. K. Hensinger

2011-06-24T23:59:59.000Z

79

An injection-locked 674 nm laser for Strontium-88 ion trapping  

E-Print Network (OSTI)

Energy levels of the valence electron of a single trapped ??Sr+ ion can be harnessed as an effective qubit for quantum information processing. The qubit transition to a metastable energy state can be stimulated by a laser ...

Katz, Rena J. (Rena Jenelle)

2012-01-01T23:59:59.000Z

80

Temperature and heating rate of ion crystals in Penning traps  

Science Conference Proceedings (OSTI)

... plasma energy (the sum of the potential and kinetic energies) per ion ... That is, the energy increase of an ion, after the cooling ... [15] A. Sřrensen and K ...

2004-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

The laser ion source trap for highest isobaric selectivity in online exotic isotope production  

Science Conference Proceedings (OSTI)

The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step after complete characterization is the construction and installation of the radiation-hard final trap structure and its first online application.

Schwellnus, F.; Gottwald, T.; Mattolat, C.; Wendt, K. [Institut fuer Physik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Catherall, R.; Crepieux, B.; Fedosseev, V.; Marsh, B.; Rothe, S.; Stora, T. [CERN, CH-1211 Geneva 23 (Switzerland); Kluge, H.-J. [GSI, Planckstrasse 1, D-64291 Darmstadt (Germany)

2010-02-15T23:59:59.000Z

82

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers  

NLE Websites -- All DOE Office Websites (Extended Search)

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift...

83

Transport of ions in a segmented linear Paul trap in printed-circuit-board technology  

E-Print Network (OSTI)

We describe the construction and operation of a segmented linear Paul trap, fabricated in printed-circuit-board technology with an electrode segment width of 500 microns. We prove the applicability of this technology to reliable ion trapping and report the observation of Doppler cooled ion crystals of Ca-40 with this kind of traps. Measured trap frequencies agree with numerical simulations at the level of a few percent from which we infer a high fabrication accuracy of the segmented trap. To demonstrate its usefulness and versatility for trapped ion experiments we study the fast transport of a single ion. Our experimental results show a success rate of 99.0(1)% for a transport distance of 2x2mm in a round-trip time of T=20us, which corresponds to 4 axial oscillations only. We theoretically and experimentally investigate the excitation of oscillations caused by fast ion transports with error-function voltage ramps: For a slightly slower transport (a round-trip shuttle within T=30us) we observe non-adiabatic motional excitation of 0.89(15)meV.

G. Huber; T. Deuschle; W. Schnitzler; R. Reichle; K. Singer; F. Schmidt-Kaler

2007-11-19T23:59:59.000Z

84

Characterization of fluorescence collection optics integrated with a micro-fabricated surface electrode ion trap  

E-Print Network (OSTI)

One of the outstanding challenges for ion trap quantum information processing is to accurately detect the states of many ions in a scalable fashion. In the particular case of surface traps, geometric constraints make imaging perpendicular to the surface appealing for light collection at multiple locations with minimal cross-talk. In this report we describe an experiment integrating Diffractive Optic Elements (DOE's) with surface electrode traps, connected through in-vacuum multi-mode fibers. The square DOE's reported here were all designed with solid angle collection efficiencies of 3.58%; with all losses included a detection efficiency of 0.388% (1.02% excluding the PMT loss) was measured with a single Ca+ ion. The presence of the DOE had minimal effect on the stability of the ion, both in temporal variation of stray electric fields and in motional heating rates.

Clark, Craig R; Ellis, A R; Hunker, Jeff; Kemme, Shanalyn A; Maunz, Peter; Tabakov, Boyan; Tigges, Chris; Stick, Daniel L

2013-01-01T23:59:59.000Z

85

Characterization of fluorescence collection optics integrated with a micro-fabricated surface electrode ion trap  

E-Print Network (OSTI)

One of the outstanding challenges for ion trap quantum information processing is to accurately detect the states of many ions in a scalable fashion. In the particular case of surface traps, geometric constraints make imaging perpendicular to the surface appealing for light collection at multiple locations with minimal cross-talk. In this report we describe an experiment integrating Diffractive Optic Elements (DOE's) with surface electrode traps, connected through in-vacuum multi-mode fibers. The square DOE's reported here were all designed with solid angle collection efficiencies of 3.58%; with all losses included a detection efficiency of 0.388% (1.02% excluding the PMT loss) was measured with a single Ca+ ion. The presence of the DOE had minimal effect on the stability of the ion, both in temporal variation of stray electric fields and in motional heating rates.

Craig R. Clark; Chin-wen Chou; A. R. Ellis; Jeff Hunker; Shanalyn A. Kemme; Peter Maunz; Boyan Tabakov; Chris Tigges; Daniel L. Stick

2013-05-21T23:59:59.000Z

86

A trapped single ion inside a Bose-Einstein condensate  

E-Print Network (OSTI)

laser light to the ions. We observe the dynamics of this effect by measuring the mean ion energy after having an initially hot ion immersed into the condensate for various interaction times, while at the same time monitoring the effects of the collisions...

Zipkes, Christoph

2011-10-11T23:59:59.000Z

87

Electron g - 2, Entanglement, and Trapped-Ion Quantum ...  

Science Conference Proceedings (OSTI)

... ion motional levels (separated in energy by h x ... as in experiments using parametric down-conversion of photons. ... A. Sorensen and K. Molmer, Phys. ...

2007-02-07T23:59:59.000Z

88

Double wells, scalar fields and quantum phase transitions in ions traps  

E-Print Network (OSTI)

Since Hund's work on the ammonia molecule, the double well potential has formed a key paradigm in physics. Its importance is further underlined by the central role it plays in the Landau theory of phase transitions. Recently, the study of entanglement properties of many-body systems has added a new angle to the study of quantum phase transitions of discrete and continuous degrees of freedom, i.e., spin and harmonic chains. Here we show that control of the radial degree of freedom of trapped ion chains allows for the simulation of linear and non-linear Klein-Gordon fields on a lattice, in which the parameters of the lattice, the non-linearity and mass can be controlled at will. The system may be driven through a phase transition creating a double well potential between different configurations of the ion crystal. The dynamics of the system are controllable, local properties are measurable and tunnelling in the double well potential would be observable.

A. Retzker; R. Thompson; D. Segal; M. B. Plenio

2008-01-04T23:59:59.000Z

89

Initial commissioning results with the NSCL Electron Beam Ion Trap  

Science Conference Proceedings (OSTI)

The ReA reaccelerator is being added to the National Superconducting Cyclotron Laboratory (NSCL) fragmentation facility in order to provide exotic rare-isotope beams, not available at the Isotope Separation On-Line facilities, in the several-MeV/u energy range. The first stage of the NSCL reaccelerator complex, consisting of an EBIT charge breeder, a room-temperature radiofrequency quadrupole (RFQ) accelerator, and superconducting linear accelerator modules, has been completed and is being put into operation. Commissioning of the EBIT has started by extracting charge-bred residual gas ions, ions created from a Ne gas jet directed across the EBIT's electron beam and ions captured from an external test ion source. Charge-bred ions from the Ne gas jet have been extracted as a pulse and accelerated through the RFQ and the two cryomodules.

Schwarz, S.; Kittimanapun, K.; Lapierre, A.; Leitner, D.; Ottarson, J.; Portillo, M. [National Superconducting Cyclotron Laboratory, NSCL, Michigan State University, East Lansing, Michigan 48824 (United States); Bollen, G. [National Superconducting Cyclotron Laboratory, NSCL, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Lopez-Urrutia, J. R. Crespo [Max-Planck Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kester, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany)

2012-02-15T23:59:59.000Z

90

Noise reduction in negative-ion quadrupole mass spectrometry  

DOE Patents (OSTI)

This invention is comprised of a quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Chastagner, P.

1991-12-31T23:59:59.000Z

91

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network (OSTI)

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Dubessy, Romain; Guidoni, Luca

2008-01-01T23:59:59.000Z

92

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network (OSTI)

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Romain Dubessy; Thomas Coudreau; Luca Guidoni

2008-12-17T23:59:59.000Z

93

Spatial correlation functions for the collective degrees of freedom of many trapped ions  

E-Print Network (OSTI)

Spatial correlation functions provide a glimpse into the quantum correlations within a quantum system. Ions in a linear trap collectively form a nonuniform, discretized background on which a scalar field of phonons propagates. Trapped ions have the experimental advantage of each having their own "built-in" motional detector: electronic states that can be coupled, via an external laser, to the ion's vibrational motion. The post-interaction electronic state can be read out with high efficiency, giving a stochastic measurement record whose classical correlations reflect the quantum correlations of the ions' collective vibrational state. Here we calculate this general result, then we discuss the long detection-time limit and specialize to Gaussian states, and finally we compare the results for thermal versus squeezed states.

Nicolas C. Menicucci; G. J. Milburn

2008-07-22T23:59:59.000Z

94

A microscopic model of electronic field noise heating in ion traps  

E-Print Network (OSTI)

Motional heating of ions in micro-fabricated traps is a challenge hindering experimental realization of large-scale quantum processing devices. Recently a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise is still vague. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first principle calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency and temperature dependence of the resulting electric field fluctuation spectrum.Our theory calculates the noise spectrum beyond the standard scenario of two-level fluctuators, by incorporating all the relevant vibrational states. The $1/f$ noise is shown to commence at roughly the frequency of the fundamental phonon transition rate and the $d^{...

Safavi-Naini, A; Weck, P; Sadeghpour, H R

2011-01-01T23:59:59.000Z

95

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents (OSTI)

A mass spectrometer and methods are disclosed for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector. 7 figs.

Tuszewski, M.G.

1997-07-22T23:59:59.000Z

96

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

Tuszewski, Michel G. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

97

Dynamics of a single trapped ion inside a nonideal QED cavity at zero temperature  

SciTech Connect

We consider a system consisting of a single ion in a Paul trap coupled to a cavity electromagnetic field mode. We analyze the fidelity of a scheme for quantum swapping between vibrational and cavity field states, when the system is in contact with a reservoir at zero temperature.

Rangel, R.; Zagury, N. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Massoni, E. [Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2004-02-01T23:59:59.000Z

98

Secondary Ion Mass Spectrometry of Environmental Aerosols  

Science Conference Proceedings (OSTI)

Atmospheric particles influence many aspects of climate, air quality and human health. Understanding the composition, chemistry and behavior of atmospheric aerosols is a key remaining challenge in improving climate models. Furthermore, particles may be traced back to a particular source based on composition, stable isotope ratios, or the presence of particular surface chemistries. Finally, the characterization of atmospheric particles in the workplace plays an important role in understanding the potential for exposure and environmental and human health effects to engineered and natural nanoscale particles. Secondary ion mass spectrometry (SIMS) is a useful tool in determining any of several aspects of the structure, composition and chemistry of these particles. Often used in conjunction with other surface analysis and electron microscopy methods, SIMS has been used to determine or confirm reactions on and in particles, the presence of particular organic species on the surface of atmospheric aerosols and several other interesting and relevant findings. Various versions of SIMS instruments – dynamic SIMS, time of flight secondary ion mass spectrometry or TOF-SIMS, nanoSIMS – have been used to determine specific aspects of aerosol structure and chemistry. This article describes the strengths of each type of SIMS instrument in the characterization of aerosols, along with guidance on sample preparation, specific characterization specific to the particular information sought in the analysis. Examples and guidance are given for each type of SIMS analysis.

Gaspar, Daniel J.; Cliff, John B.

2010-08-01T23:59:59.000Z

99

Umklapp collisions and center of mass oscillation of a trapped Fermi gas  

E-Print Network (OSTI)

Starting from the the Boltzmann equation, we study the center of mass oscillation of a harmonically trapped normal Fermi gas in the presence of a one-dimensional periodic potential. We show that for values of the the Fermi energy above the first Bloch band the center of mass motion is strongly damped in the collisional regime due to umklapp processes. This should be contrasted with the behaviour of a superfluid where one instead expects the occurrence of persistent Josephson-like oscillations.

G. Orso; L. P. Pitaevskii; S. Stringari

2004-02-20T23:59:59.000Z

100

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers  

NLE Websites -- All DOE Office Websites (Extended Search)

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber. Available for thumbnail of Feynman Center (505) 665-9090 Email Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

A microscopic model of electronic field noise heating in ion traps  

E-Print Network (OSTI)

Motional heating of ions in micro-fabricated traps is a challenge hindering experimental realization of large-scale quantum processing devices. Recently a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise is still vague. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first principle calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency and temperature dependence of the resulting electric field fluctuation spectrum.Our theory calculates the noise spectrum beyond the standard scenario of two-level fluctuators, by incorporating all the relevant vibrational states. The $1/f$ noise is shown to commence at roughly the frequency of the fundamental phonon transition rate and the $d^{-4}$ dependence with distance of the ion from the electrode surface is established.

A. Safavi-Naini; P. Rabl; P. Weck; H. R. Sadeghpour

2011-06-10T23:59:59.000Z

102

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

SciTech Connect

Secondary ion mass spectrometry (SIMS) has seen increased application for high spatial chemical imaging of complex biological surfaces. The advent and commercial availability of cluster and polyatomic primary ion sources (e.g. Au and Bi cluster and buckminsterfullerene (C60)) provide improved secondary ion yield and decreased fragmentation of surface species, thus accessibility to intact molecular ions. Despite developments in primary ion sources, development of mass spectrometers to fully exploit their advantages has been limited. Tandem mass spectrometry for identification of secondary ions is highly desirable, but implementation has proven to be difficult. Similarly, high mass resolution and high mass measurement accuracy would greatly improve the chemical specificity of SIMS. Here we combine, for the first time, the advantages of a C60 primary ion source with the ultra-high mass resolving power and high mass measurement accuracy of Fourier transform ion cyclotron resonance mass spectrometry. Mass resolving power in excess of 100,000 (m/?m50%) is demonstrated, with mass measurement accuracies below 3 parts-per-million. Imaging of mouse brain tissue at 40 ?m pixel size is shown. Tandem mass spectrometry of ions from biological tissue is demonstrated and molecular formulae can be assigned to fragment ions.

Smith, Donald F.; Robinson, Errol W.; Tolmachev, Aleksey V.; Heeren, Ronald M.; Pasa-Tolic, Ljiljana

2011-12-15T23:59:59.000Z

103

Ion source for high-precision mass spectrometry  

DOE Patents (OSTI)

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit.

Todd, Peter J. (Oak Ridge, TN); McKown, Henry S. (Oak Ridge, TN); Smith, David H. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

104

Shell Structure, Melting and Dynamics of Ion Clusters Confined in an Octupolar Trap  

Science Conference Proceedings (OSTI)

The stable structures of clusters of identical ions trapped in an isotropic octupolar trap are investigated using global optimization methods. These clusters form well defined shells of ions that are approximately solutions of the Thomson problem. In particular, magic numbers are found to correlate with highly symmetric configurations. Using Monte Carlo simulations, finite temperature properties are also investigated. Melting proceeds from the core, and takes place through a very progressive loss of the shell structure. The hollow shape is eventually lost at very high temperatures, where the ions essentially feel the confinement but not the Coulomb repulsion. The vibrational density of states shows marked differences with the harmonic case, but also with bulk Wigner crystals. The variations of the maximal Lyapunov exponent obtained from additional molecular dynamics trajectories reveals that the dynamics becomes increasingly chaotic as the temperature increases. With the decreasing influence of the Coulomb interaction, a more regular behavior is found at very high temperatures but, contrary to the quadrupolar case, still highly chaotic.

Calvo, F. [LASIM, Universite Claude Bernard and CNRS, Bat. A. Kastler, 43 Bd du 11 Novembre 1918, F69622 Villeurbanne Cedex (France); Yurtsever, E. [Koc University, Rumelifeneriyolu, Sariyer, Istanbul 34450 (Turkey)

2009-12-03T23:59:59.000Z

105

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

E-Print Network (OSTI)

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

L. F. Wei; Franco Nori

2004-11-18T23:59:59.000Z

106

Prethermalization and dynamical transition in an isolated trapped ion spin chain  

E-Print Network (OSTI)

We propose an experimental scheme to observe prethermalization and dynamical transition in one-dimensional XY spin chain with long range interaction and inhomogeneous lattice spacing, which can be readily implemented with the recently developed trapped-ion quantum simulator. Local physical observables are found to relax to prethermal values at intermediate time scale, followed by complete relaxation to thermal values at much longer time. The physical origin of prethermalization is explained by spotting a non-trivial structure in lower half of the energy spectrum. The dynamical behavior of the system is shown to cross difference phases when the interaction range is continuously tuned, indicating the existence of dynamical phase transition.

Zhe-Xuan Gong; L. -M. Duan

2013-05-05T23:59:59.000Z

107

Dirac Equation and Quantum Relativistic Effects in a Single Trapped Ion  

Science Conference Proceedings (OSTI)

We present a method of simulating the Dirac equation in 3+1 dimensions for a free spin-1/2 particle in a single trapped ion. The Dirac bispinor is represented by four ionic internal states, and position and momentum of the Dirac particle are associated with the respective ionic variables. We show also how to simulate the simplified 1+1 case, requiring the manipulation of only two internal levels and one motional degree of freedom. Moreover, we study relevant quantum-relativistic effects, like the Zitterbewegung and Klein's paradox, the transition from massless to massive fermions, and the relativistic and nonrelativistic limits, via the tuning of controllable experimental parameters.

Lamata, L.; Leon, J. [Instituto de Matematicas y Fisica Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); Schaetz, T. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru)

2007-06-22T23:59:59.000Z

108

Linear electronic field time-of-flight ion mass spectrometers  

DOE Patents (OSTI)

Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

Funsten, Herbert O. (Los Alamos, NM)

2010-08-24T23:59:59.000Z

109

Towards in-situ cleaning of a trapped ion quantum computer  

E-Print Network (OSTI)

A plasma glow discharge system was created using a conventional microwave oven to ignite and maintain the plasma. The system was used for plasma cleaning and its properties were analysed to assess its viability for removing surface contaminants, which cause anomalous heating, from Paul trap electrodes used in ion trapping. Qualitative results showed that the argon plasma could remove copper oxide layers formed on thin sheets in 1-2 minutes. The addition of air into the plasma system allowed for the cleaning of more complex hydrocarbon contaminants, as highlighted by the removal of permanent marker pen. The surface removal rate of the system was evaluated by measuring the time taken to remove gold plating from washers and aluminium plates. A nominal rate of 5-15 nm per min was found under optimal conditions. Plasma treatment, in addition to wet chemical cleaning, was found to increase the finesse of an optical cavity by a factor of two, compared to acetone cleaning alone. These results are promising for the system's in-situ use on Paul trap electrodes and could be a feasible technique for increasing their lifetime.

Timothy Harrison

2012-07-08T23:59:59.000Z

110

Two-photon spectroscopy of trapped HD$^+$ ions in the Lamb-Dicke regime  

E-Print Network (OSTI)

We study the feasibility of nearly-degenerate two-photon rovibrational spectroscopy in ensembles of trapped, sympathetically cooled hydrogen molecular ions using a resonance-enhanced multiphoton dissociation (REMPD) scheme. Taking advantage of quasi-coincidences in the rovibrational spectrum, the excitation lasers are tuned close to an intermediate level to resonantly enhance two-photon absorption. Realistic simulations of the REMPD signal are obtained using a four-level model that takes into account saturation effects, ion trajectories, laser frequency noise and redistribution of population by blackbody radiation. We show that the use of counterpropagating laser beams enables optical excitation in an effective Lamb-Dicke regime. Sub-Doppler lines having widths in the 100 Hz range can be observed with good signal-to-noise ratio for an optimal choice of laser detunings. Our results indicate the feasibility of molecular spectroscopy at the $10^{-14}$ accuracy level for improved tests of molecular QED, a new det...

Tran, Vu Quang; Douillet, Albane; Koelemeij, Jeroen C J; Hilico, Laurent

2013-01-01T23:59:59.000Z

111

A very low energy compact electron beam ion trap for spectroscopic research in Shanghai  

Science Conference Proceedings (OSTI)

In this paper, a new compact low energy electron beam ion trap, SH-PermEBIT, is reported. This electron beam ion trap (EBIT) can operate in the electron energy range of 60-5000 eV, with a current density of up to 100 A/cm{sup 2}. The low energy limit of this machine sets the record among the reported works so far. The magnetic field in the central drift tube region of this EBIT is around 0.5 T, produced by permanent magnets and soft iron. The design of this EBIT allows adjustment of the electron gun's axial position in the fringe field of the central magnetic field. This turned out to be very important for optimizing the magnetic field in the region of the electron gun and particularly important for low electron beam energy operation, since the magnetic field strength is not tunable with permanent magnets. In this work, transmission of the electron beam as well as the upper limit of the electron beam width under several conditions are measured. Spectral results from test operation of this EBIT at the electron energies of 60, 315, 2800, and 4100 eV are also reported.

Xiao, J.; Fei, Z.; Yang, Y.; Jin, X.; Lu, D.; Shen, Y.; Hutton, R.; Zou, Y. [The Key lab of Applied Ion Beam Physics, Ministry of Education, Shanghai (China); Shanghai EBIT lab, Institute of Modern Physics, Fudan University, Shanghai (China); Liljeby, L. [Manne Siegbahn Laboratory, Stockholm University, Stockholm (Sweden)

2012-01-15T23:59:59.000Z

112

An omegatron mass spectrometer for plasma ion species analysis  

DOE Green Energy (OSTI)

An omegatron mass spectrometer which can be used to measure the ion species and charge state distribution in a magnetized plasma is described. In the conventional omegatron, ions are formed as the result of gas ionization by a fine electron beam passing through the center of the analyzer along the magnetic field. In the plasma omegatron, the plasma ions are entering the analyzer through a small floating aperture. We employ a biasing technique to reduce the ion velocity along the magnetic field and, thus, achieve improved ion collection and sensitivity. Experiments have been performed to demonstrate the instrument's operation in the PISCES-A linear plasma device, at a magnetic field {ital B}=1.3 kG. Mass spectra have been obtained in hydrogen, helium, and nitrogen plasmas, and typical results are presented.

Wang, E.Y.; Schmitz, L.; Ra, Y.; LaBombard, B.; Conn, R.W. (Institute of Plasma and Fusion Research, (USA) Department of Mechanical, Aerospace, and Nuclear Engineering, Los Angeles, CA (USA) University of California, Los Angeles, Los Angeles, CA (USA))

1990-08-01T23:59:59.000Z

113

Quantum measurement and nonclassical vibration of an ion in a trap  

Science Conference Proceedings (OSTI)

The microwave-induced dynamics of the nuclear spin and the laser-induced dynamics of the centre-of-mass motion of individual ions have been studied: (i) The phase shift of the hyperfine Larmor precession of a ground-state 171 Yb + ion upon pulsed variation of the ambient magnetic field has been measured by microwave-optical double resonance interpreted in terms of Mach-Zehnder interferometry and quantum ergodicity. Even a single measurement yields (partial) phase information. At the extremes of the fringes

R. Huesmann; Ch. Balzer; B. Appasamy; Y. Stalgies; P. E. Toschek

1999-01-01T23:59:59.000Z

114

Towards in-situ cleaning of a trapped ion quantum computer  

E-Print Network (OSTI)

A plasma glow discharge system was created using a conventional microwave oven to ignite and maintain the plasma. The system was used for plasma cleaning and its properties were analysed to assess its viability for removing surface contaminants, which cause anomalous heating, from Paul trap electrodes used in ion trapping. Qualitative results showed that the argon plasma could remove copper oxide layers formed on thin sheets in 1-2 minutes. The addition of air into the plasma system allowed for the cleaning of more complex hydrocarbon contaminants, as highlighted by the removal of permanent marker pen. The surface removal rate of the system was evaluated by measuring the time taken to remove gold plating from washers and aluminium plates. A nominal rate of 5-15 nm per min was found under optimal conditions. Plasma treatment, in addition to wet chemical cleaning, was found to increase the finesse of an optical cavity by a factor of two, compared to acetone cleaning alone. These results are promising for the sy...

Harrison, Timothy

2012-01-01T23:59:59.000Z

115

On resonant destabilization of toroidal Alfven eigenmodes by circulating and trapped energetic ions/alpha particles in tokamaks  

SciTech Connect

Toroidal Alfven eigenmodes are shown to be resonantly destabilized by both circulating and trapped energetic ions/alpha particles. In particular, the energetic circulating ions are shown to resonate with the mode not only at the Alfven speed ({upsilon}{sub A}), but also one-third of this speed, while resonances exist between trapped energetic ions and the wave when {upsilon} = {upsilon}{sub A}/21{epsilon}{sup {1/2}} (l=integer, {epsilon}=r/R is the local inverse aspect ratio), although the instability becomes weaker for resonances other than the fundamental. The oft-quoted criterion that instability requires super-Alfvenic ion velocities is thus sufficient but not necessary. 14 refs.

Biglari, H.; Zonca, F.; Chen, L.

1991-10-01T23:59:59.000Z

116

Conditioning of ion sources for mass spectrometry of plasmas  

DOE Green Energy (OSTI)

Mass spectrometry is a useful diagnostic technique for monitoring plasma species and plasma-surface interactions. In order to maximize the sensitivity of measurements of hydrogen-fueled fusion plasmas or hydrogen-based discharge cleaning and etching plasmas, the ion sources of mass spectrometers are operated at or near the high pressure limit of 10/sup -4/ Torr (10/sup -2/ Pa). Such high ambient pressures of hydrogen give rise to high background levels of residual gases such as H/sub 2/O, CO, and CH/sub 4/, due to surface reactions on the ion source electrodes. For a commonly used ion source configuration, the residual gas production is a linear function of the ambient H/sub 2/ pressure. Hydrogen conditioning can reduce the absolute residual gas levels. Steady-state residual gas production is observed in a conditioned ion source, which is related to a balance of diffusion and sorption on the electrode surfaces.

Dylla, H.F.; Blanchard, W.R.

1983-02-01T23:59:59.000Z

117

Inhibition of the current-driven ion wave instability by electron trapping in the FM-1 spherator  

SciTech Connect

An experimental analysis is made of the scattering of microwaves by the density fluctuations due to the current-driven ion wave instability in a toroidal plasma confinement device, the FM-1 spherator. It is found that the instability exists in the collisional regime and it is inhibited (i.e., quenched by two orders in magnitude) in the trapped-electron (i.e., banana) regime. The inhibition occurs when the electron collision frequency is about equal to the electron bounce frequency between mirror trapping. (auth)

Arunasalam, V.; Okabayaski, M.; Hawryluk, R.J.; Suckewer, S.

1975-10-01T23:59:59.000Z

118

Penning trap mass measurements on (99-109)$Cd with ISOLTRAP and implications on the rp process  

E-Print Network (OSTI)

Penning trap mass measurements on neutron-deficient Cd isotopes (99-109)Cd have been performed with the ISOLTRAP mass spectrometer at ISOLDE/CERN, all with relative mass uncertainties below 3*10^8. A new mass evaluation has been performed. The mass of 99Cd has been determined for the first time which extends the region of accurately known mass values towards the doubly magic nucleus 100Sn. The implication of the results on the reaction path of the rp process in stellar X-ray bursts is discussed. In particular, the uncertainty of the abundance and the overproduction created by the rp-process for the mass A = 99 is demonstrated by reducing the uncertainty of the proton-separation energy of 100In Sp(100In) by a factor of 2.5.

M. Breitenfeldt; G. Audi; D. Beck; K. Blaum; S. George; F. Herfurth; A. Herlert; A. Kellerbauer; H. -J. Kluge; M. Kowalska; D. Lunney; S. Naimi; D. Neidherr; H. Schatz; S. Schwarz; L. Schweikhard

2009-08-18T23:59:59.000Z

119

Simulation of lean NOx trap performance with microkinetic chemistry and without mass transfer.  

SciTech Connect

A microkinetic chemical reaction mechanism capable of describing both the storage and regeneration processes in a fully formulated lean NO{sub x} trap (LNT) is presented. The mechanism includes steps occurring on the precious metal, barium oxide (NO{sub x} storage), and cerium oxide (oxygen storage) sites of the catalyst. The complete reaction set is used in conjunction with a transient plug flow reactor code to simulate not only conventional storage/regeneration cycles with a CO/H{sub 2} reductant, but also steady flow temperature sweep experiments that were previously analyzed with just a precious metal mechanism and a steady state code. The results show that NO{sub x} storage is not negligible during some of the temperature ramps, necessitating a re-evaluation of the precious metal kinetic parameters. The parameters for the entire mechanism are inferred by finding the best overall fit to the complete set of experiments. Rigorous thermodynamic consistency is enforced for parallel reaction pathways and with respect to known data for all of the gas phase species involved. It is found that, with a few minor exceptions, all of the basic experimental observations can be reproduced with these purely kinetic simulations, i.e., without including mass-transfer limitations. In addition to accounting for normal cycling behavior, the final mechanism should provide a starting point for the description of further LNT phenomena such as desulfation and the role of alternative reductants.

Larson, Rich; Daw, C. Stuart (Oak Ridge National Laboratory, Knoxville, TN); Pihl, Josh A. (Oak Ridge National Laboratory, Knoxville, TN); Chakravarthy, V. Kalyana (Oak Ridge National Laboratory, Knoxville, TN)

2011-08-01T23:59:59.000Z

120

Adiabatic quantum simulation with a segmented ion trap: Application to long-distance entanglement in quantum spin systems  

E-Print Network (OSTI)

We discuss systems of ions in segmented linear Paul traps for the quantum simulation of spin models which exhibit long-distance entanglement (LDE) in the ground state. The axial potential can be tailored to create different coupling patterns suitable to create LDE in quantum spin chains. Microwave pulses are used to implement various kinds of spin-spin interaction Hamiltonians, which can be varied adiabatically thereby realizing the adiabatic preparation of the ground states of quantum spin Hamiltonians exhibiting LDE.

S. Zippilli; M. Johanning; S. M. Giampaolo; Ch. Wunderlich; F. Illuminati

2013-03-31T23:59:59.000Z

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121

Ion cyclotron resonance cell  

DOE Patents (OSTI)

An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

Weller, R.R.

1995-02-14T23:59:59.000Z

122

Exact mapping of the 2+1 Dirac oscillator onto the Jaynes-Cummings model: Ion-trap experimental proposal  

Science Conference Proceedings (OSTI)

We study the dynamics of the 2+1 Dirac oscillator exactly and find spin oscillations due to a Zitterbewegung of purely relativistic origin. We find an exact mapping of this quantum-relativistic system onto a Jaynes-Cummings model, describing the interaction of a two-level atom with a quantized single-mode field. This equivalence allows us to map a series of quantum optical phenomena onto the relativistic oscillator and vice versa. We make a realistic experimental proposal, in reach with current technology, for studying the equivalence of both models using a single trapped ion.

Bermudez, A.; Martin-Delgado, M. A. [Departamento de Fisica Teorica I, Universidad Complutense, 28040 Madrid (Spain); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru)

2007-10-15T23:59:59.000Z

123

Mass Analysis, Directed Ion Transfer, and Field Shaping in ...  

Science Conference Proceedings (OSTI)

... For instance, electric trapping fields can be optimized by changing the potential ... Holes are laser-drilled for vias (electrical connections between ...

2011-03-01T23:59:59.000Z

124

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high (n,f) reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1998-07-21T23:59:59.000Z

125

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1998-01-01T23:59:59.000Z

126

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1999-01-01T23:59:59.000Z

127

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1999-02-16T23:59:59.000Z

128

Unpolarized, incoherent repumping light for prevention of dark states in a trapped and laser-cooled single ion  

E-Print Network (OSTI)

Many ion species commonly used for laser-cooled ion trapping studies have a low-lying metastable 2D3/2 state that can become populated due to spontaneous emission from the 2P1/2 excited state. This requires a repumper laser to maintain the ion in the Doppler cooling cycle. Typically the 2D3/2 state, or some of its hyperfine components if the ion has nuclear spin, has a higher multiplicity than the upper state of the repumping transition. This can lead to dark states, which have to be destabilized by an external magnetic field or by modulating the polarization of the repumper laser. We propose using unpolarized, incoherent amplified spontaneous emission (ASE) to drive the repumping transition. An ASE source offers several advantages compared to a laser. It prevents the buildup of dark states without external polarization modulation even in zero magnetic field, it can drive multiple hyperfine transitions simultaneously, and it requires no frequency stabilization. These features make it very compact and robust, which is essential for the development of practical, transportable optical ion clocks. We construct a theoretical model for the ASE radiation, including the possibility of the source being partially polarized. Using 88Sr+ as an example, the performance of the ASE source compared to a single-mode laser is analyzed by numerically solving the eight-level density matrix equations for the involved energy levels. Finally a reduced three-level system is derived, yielding a simple formula for the excited state population and scattering rate, which can be used to optimize the experimental parameters. The required ASE power spectral density can be obtained with current technology.

T. Lindvall; T. Fordell; I. Tittonen; M. Merimaa

2013-01-23T23:59:59.000Z

129

Full quantum treatment of Rabi oscillation driven by a pulse train and its application in ion-trap quantum computation  

E-Print Network (OSTI)

Rabi oscillation of a two-level system driven by a pulse train is a basic process involved in quantum computation. We present a full quantum treatment of this process and show that the population inversion of this process collapses exponentially, has no revival phenomenon, and has a dual-pulse structure in every period. As an application, we investigate the properties of this process in ion-trap quantum computation. We find that in the Cirac--Zoller computation scheme, when the wavelength of the driving field is of the order $10^{-6}$ m, the lower bound of failure probability is of the order $10^{-2}$ after about $10^2$ controlled-NOT gates. This value is approximately equal to the generally-accepted threshold in fault-tolerant quantum computation.

Li Yang; Biyao Yang; Yufu Chen

2010-10-28T23:59:59.000Z

130

Developing Fieldable Systems for Chemical Sensing Using Field Asymmetric Ion Mobility Spectrometry and Mass Spectrometry  

SciTech Connect

Currently, there is an urgent need for field-rugged and field-programmable sensor systems that provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. These devices must be portable, low cost, robust, and provide accurate measurements to avoid both false positive and negative results. Furthermore, the information provided by the devices must be received in a timely manner so that informed decisions can be immediately made and the appropriate actions taken. Two technologies that are unparalleled in their sensitivity, selectivity, and trace-level detection capabilities are field asymmetric ion mobility spectrometry (FAIMS) and mass spectrometry. Here, we will show progress that has been made toward developing fieldable FAIMS systems and mass spectrometers. Working in collaboration with Sionex Corporation, the microDMx detector was equipped with a continuous air sampling system to develop selective methods for the analysis of compounds of interest. A microdiaphragm pump (KNF Neuberger, Inc.) is used to pull in gas-phase analytes directly from the air for separation and detection with the FAIMS system. The FAIMS evaluation platform (SVAC) unit currently measures 9.8-inch x 4.6-inch x 3.2-inch, weighs 3.1 lb, and utilizes a {sup 63}Ni source to ionize incoming compounds. Analytes entering the unit are separated and identified by their characteristic response to the compensation voltage (V{sub c}) at a given rf field strength (V{sub rf}). This response has been observed to be unique for a wide range of substances studied. If additional verification were required or a targeted analyte present in a complex chemical matrix, a FAIMS unit equipped with a fast gas chromatography column has been evaluated. The unit combines the separation capabilities of gas chromatography with the selectivity of FAIMS. It measures 9.5-inch x 5.25-inch x 3.5-inch, weighs 3.8 lb, and uses a 10.6 eV photoionization source. Analytes are identified both by their elution time from the column and by the characteristic response in the FAIMS spectrum. Analysis times required to obtain results for most analytes examined are less than three minutes. A fieldable mass spectrometer system is also being developed that includes sampling, ionization, mass selection and detection, vacuum technology, and analytical methodology with remote data transmission. Multiple methods for mass selection are being explored, including both Penning and Paul type ion traps as well as a quadrupole system to determine which is best suited for a portable mass spectrometer. Several ionization sources and ion counting methods will also be evaluated to establish their effectiveness with each system. The intended result of this project is a handheld mass spectrometer system capable of field deployment for the detection and identification of a wide range of gas-phase CBE species.

Kevin Kyle, Stephan Weeks, R. Trainham

2008-03-01T23:59:59.000Z

131

Tavis-Cummings model and collective multiqubit entanglement in trapped ions  

Science Conference Proceedings (OSTI)

We present a method of generating collective multiqubit entanglement via global addressing of an ion chain performing blue and red Tavis-Cummings interactions, where several qubits are coupled to a collective motional mode. We show that a wide family of Dicke states and irradiant states can be generated by single global laser pulses, unitarily or helped with suitable postselection techniques.

Retzker, A. [Institute for Mathematical Sciences, Imperial College London, SW7 2PE (United Kingdom); QOLS, The Blackett Laboratory, Imperial College London, Prince Consort Rd., SW7 2BW (United Kingdom); Solano, E. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado Postal 1761, Lima (Peru); Reznik, B. [Department of Physics and Astronomy, Tel-Aviv University, Tel Aviv 69978 (Israel)

2007-02-15T23:59:59.000Z

132

Geometric phase gate on an optical transition for ion trap quantum computation  

E-Print Network (OSTI)

We propose a geometric phase gate of two ion qubits that are encoded in two levels linked by an optical dipole-forbidden transition. Compared to hyperfine geometric phase gates mediated by electric dipole transitions, the gate has many interesting properties, such as very low spontaneous emission rates, applicability to magnetic field insensitive states, and use of a co-propagating laser beam geometry. We estimate that current technology allows for infidelities of around 10$^{-4}$.

Kim, K; Aolita, L; Häffner, H; Nebendahl, V; Blatt, R

2007-01-01T23:59:59.000Z

133

Geometric phase gate on an optical transition for ion trap quantum computation  

E-Print Network (OSTI)

We propose a geometric phase gate of two ion qubits that are encoded in two levels linked by an optical dipole-forbidden transition. Compared to hyperfine geometric phase gates mediated by electric dipole transitions, the gate has many interesting properties, such as very low spontaneous emission rates, applicability to magnetic field insensitive states, and use of a co-propagating laser beam geometry. We estimate that current technology allows for infidelities of around 10$^{-4}$.

K. Kim; C. F. Roos; L. Aolita; H. Haeffner; V. Nebendahl; R. Blatt

2007-10-21T23:59:59.000Z

134

High-Sensitivity Ion Mobility Spectrometry/Mass ...  

... Bowers, M. T.; Kemper, P. R.; von Helden, G.; van Koppen, P. A. M. Science 1993, 260, 1446 ... (Ł), which results in large ion ... and R d is the ...

135

Measurements of the intercombination and forbidden lines from helium-like ions in Tokamaks and Electron Beam Ion Traps  

SciTech Connect

The paper reviews the results from tokamak experiments for the line ratios x/w, y/w, and z/w from helium-like ions with Z in the range from 14 to 28. With exception of the DITE experiments, where these line ratios were found to be in agreement with theoretical predictions, all other tokamak experiments yielded values that were significantly larger than predicted. The reasons for these discrepancies are not yet understood. It is possible that radial profile effects were not properly taken into account in the majority of the tokamak experiments. The paper also gives a short historical review of the X-ray diagnostic developments and also presents very recent data from a new type of X-ray imaging crystal spectrometer, which records spatially resolved spectra with a spatial resolution of about 1 cm in the plasma. These new data can be Abel inverted, so that it will be possible to determine line ratios at each radial position in the plasma. Effects of radial profiles, which may have affected the chord-integrated measurements of the past, will thus be eliminated in the future.

Bitter, M; Hill, K W; von Goeler, S; Stodiek, W; Beiersdorfer, P; Rice, J E; Ince-Cushman, A

2007-08-22T23:59:59.000Z

136

Mechanism of Radial Redistribution of Energetic Trapped Ions Due to m=2/n=1 Internal Reconnection in Joint European Torus Shear Optimized Plasmas  

DOE Green Energy (OSTI)

Internal radial redistribution of MeV energy ICRF-driven hydrogen minority ions was inferred from neutral particle analyzer measurements during large amplitude MHD activity leading to internal reconnection in Shear Optimized plasmas in the Joint European Torus (JET). A theory is developed for energetic ion redistribution during a reconnection driven by an m=2/n=1 internal kink mode. Plasma motion during reconnection generates an electric field which can change the energy and radial position of the energetic ions. The magnitude of ion energy change depends on the value of the safety factor at the plasma core from which the energetic ions are redistributed. A relation is found for corresponding change in canonical momentum. P(subscript phi), which leads to radial displacement of the ions. The model yields distinctive new features of energetic ion redistribution under such conditions. Predicted characteristics of ion redistribution are compared with the NPA measurements, and good correlation is found. Sometimes fast ions were transported to the plasma edge due to interaction with a long-lived magnetic island which developed after the reconnection and had chirping frequency in the laboratory frame. Convection of resonant ions trapped in a radially moving phase-space island is modeled to understand the physics of such events.

N.N. Gorelenkov; A. Gondhalekar; A.A. Korotkov; S.E. Sharapov; D. Testa; and Contributors to the EFDA-JET Workprogramme

2002-01-18T23:59:59.000Z

137

A study of the formation of cluster ions from metal acetates using plasma desorption mass spectrometry  

E-Print Network (OSTI)

A novel application of desorption/ionization methods of mass spectrometry, e. g. plasma desorption mass spectrometry (PDMS), is the analysis of both the composition and structure of solid materials in one experiment. Cluster ions emitted from the impact of a 252Cf fission fragment on a surface may represent a "view" of the solid construction over atomic distances if composed of atoms from adjacent sites in the surface. A clearer understanding of the mechanism of secondary cluster ion formation is necessary to evaluate the usefulness of PDMS as a surface characterization technique. The aim of this research was to use metal acetate samples to study secondary cluster ion formation in PDMS. In two sets of experiments, metal acetates from period IV and group IIB of the periodic table were used to measure the influence on cluster formation by the ground state electronic configuration and the ionic size, respectively, of the metal constituent. Relative yields for homologous negative and positive secondary cluster ions were determined and compared to thermochemical properties of the metal ion or the metal acetate molecule (AHf and lattice energy). Secondary ions in negative PDMS mass spectra attributable to a gas phase recombination formation mechanism follow trends predicted by these thermochemical properties. Another series of cluster ions, however, with the composition [M(Ac)2]Ac-(where Ac = acetate) does not follow the same trends, indicating possible formation via intact emission from the solid surface. Positive secondary cluster ions showed differences from the negative ions both in the relative yield distribution and the types of ions observed. Positive cluster ions from metal acetates from the fourth period of the periodic table were mainly metal oxides. On the other hand, positive clusters ions from the group IIB of the periodic table were mainly mirror images of the negative spectra. These differences suggest that the bonding characteristics of the metal ion play an important role in the secondary cluster ion formation process.

Mendez Silvagnoli, Winston Reinaldo

1995-01-01T23:59:59.000Z

138

Simulation studies for operating electron beam ion trap at very low energy for disentangling edge plasma spectra  

SciTech Connect

Electron beam ion traps (EBITs) are very useful tools for disentanglement studies of atomic processes in plasmas. In order to assist studies on edge plasma spectroscopic diagnostics, a very low energy EBIT, SH-PermEBIT, has been set up at the Shanghai EBIT lab. In this work, simulation studies for factors which hinder an EBIT to operate at very low electron energies were made based on the Tricomp (Field Precision) codes. Longitudinal, transversal, and total kinetic energy distributions were analyzed for all the electron trajectories. Influences from the electron current and electron energy on the energy depression caused by the space charge are discussed. The simulation results show that although the energy depression is most serious along the center of the electron beam, the electrons in the outer part of the beam are more likely to be lost when an EBIT is running at very low energy. Using the simulation results to guide us, we successfully managed to reach the minimum electron beam energy of 60 eV with a beam transmission above 57% for the SH-PermEBIT. Ar and W spectra were measured from the SH-PermEBIT at the apparent electron beam energies (read from the voltage difference between the electron gun cathode and the central drift tube) of 60 eV and 1200 eV, respectively. The spectra are shown in this paper.

Jin Xuelong; Fei Zejie; Xiao Jun; Lu Di; Hutton, Roger; Zou Yaming [Key Lab of Applied Ion Beam Physics, Ministry of Education, China and Shanghai EBIT laboratory, Modern Physics Institute, Fudan University, Shanghai (China)

2012-07-15T23:59:59.000Z

139

Discovery of {sup 229}Rn and the Structure of the Heaviest Rn and Ra Isotopes from Penning-Trap Mass Measurements  

SciTech Connect

The masses of the neutron-rich radon isotopes {sup 223-229}Rn have been determined for the first time, using the ISOLTRAP setup at CERN ISOLDE. In addition, this experiment marks the first discovery of a new nuclide, {sup 229}Rn, by Penning-trap mass measurement. The new, high-accuracy data allow a fine examination of the mass surface, via the valence-nucleon interaction {delta}V{sub pn}. The results reveal intriguing behavior, possibly reflecting either a N=134 subshell closure or an octupolar deformation in this region.

Neidherr, D.; Boehm, Ch. [Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Audi, G.; Lunney, D.; Minaya-Ramirez, E.; Naimi, S. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, Orsay (France); Beck, D.; Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH Darmstadt, 64291 Darmstadt (Germany); Blaum, K.; George, S.; Kellerbauer, A. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Breitenfeldt, M.; Rosenbusch, M.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Cakirli, R. B. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Department of Physics, Istanbul University, Istanbul (Turkey); Casten, R. F. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8124 (United States); Herlert, A.; Kowalska, M. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Noah, E.; Penescu, L. [Accelerators and Beams Department, CERN, 1211 Geneva 23 (Switzerland)] (and others)

2009-03-20T23:59:59.000Z

140

Angular emission of ions and mass deposition from femtosecond and nanosecond laser-produced plasmas  

SciTech Connect

We investigated the angular distribution of ions and atoms emanating from femto- and nanosecond laser-produced metal plasmas under similar laser fluence conditions. For producing plasmas, aluminum targets are ablated in vacuum employing pulses from a Ti:Sapphire ultrafast laser (40 fs, 800 nm) and an Nd:YAG laser (6 ns, 1064 nm). The angular distribution of ion emission as well as the kinetic energy distribution is characterized by a Faraday cup, while a quartz microbalance is used for evaluating deposited mass. The ion and deposited mass features showed that fs laser ablated plasmas produced higher kinetic energy and more mass per pulse than ns plumes over all angles. The ion flux and kinetic energy studies show fs laser plasmas produce narrower angular distribution while ns laser plasmas provide narrower energy distribution.

Verhoff, B.; Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2012-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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141

LOW-TEMPERATURE ION TRAP STUDIES OF N{sup +}({sup 3} P{sub ja} ) + H{sub 2}(j) {yields} NH{sup +} + H  

SciTech Connect

Using a low-temperature 22-pole ion trap apparatus, detailed measurements for the title reaction have been performed between 10 K and 100 K in order to get some state specific information about this fundamental hydrogen abstraction process. The relative population of the two lowest H{sub 2} rotational states, j = 0 and 1, has been varied systematically. NH{sup +} formation is nearly thermo-neutral; however, to date, the energetics are not known with the accuracy required for low-temperature astrochemistry. Additional complications arise from the fact that, so far, there is no reliable theoretical or experimental information on how the reactivity of the N{sup +} ion depends on its fine-structure (FS) state {sup 3} P{sub ja} . Since in the present trapping experiment, thermalization of the initially hot FS population competes with hydrogen abstraction, the evaluation of the decay of N{sup +} ions over long storage times and at various He and H{sub 2} gas densities provides information on these processes. First assuming strict adiabatic behavior, a set of state specific rate coefficients is derived from the measured thermal rate coefficients. In addition, by recording the disappearance of the N{sup +} ions over several orders of magnitude, information on nonadiabatic transitions is extracted including FS-changing collisions.

Zymak, I.; Hejduk, M.; Mulin, D.; Plasil, R.; Glosik, J.; Gerlich, D. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic)

2013-05-01T23:59:59.000Z

142

More than mass proportional heating of heavy ions by supercritical collisionless shocks in the solar corona  

E-Print Network (OSTI)

We propose a new model for explaining the observations of more than mass proportional heating of heavy ions in the polar solar corona. We point out that a large number of small scale intermittent shock waves can be present in the solar corona. The energization mechanism is, essentially, the ion reflection off supercritical quasi-perpendicular collisionless shocks in the corona and the subsequent acceleration by the motional electric field ${\\bf E} = - (1/c) {\\bf V} \\times {\\bf B}$. The acceleration due to ${\\bf E}$ is perpendicular to the magnetic field, in agreement with observations, and is more than mass proportional with respect to protons, because the heavy ion orbit is mostly upstream of the quasi-perpendicular shock foot. The observed temperature ratios between O$^{5+}$ ions and protons in the polar corona, and between $\\alpha$ particles and protons in the solar wind are easily recovered.

Zimbardo, Gaetano

2009-01-01T23:59:59.000Z

143

Trapped ytterbium ions for scalable quantum Ion Quantum Technology Group, Department of Physics and Astronomy, University of Sussex, Brighton, East Sussex,  

E-Print Network (OSTI)

.069(1) MHz y / 2 = 2.110(1) MHz z / 2 = 1.030(1) MHz Vrf = 680(10) V rf / 2 = 21.48 MHz Trap depth 4.9(2) e

Hensinger, Winfried

144

Charge Retention by Gold Clusters on Surfaces Prepared Using Soft Landing of Mass Selected Ions  

Science Conference Proceedings (OSTI)

Monodisperse gold clusters have been prepared on surfaces in different charge states through soft landing of mass-selected ions. Ligand-stabilized gold clusters were prepared in methanol solution by reduction of chloro(triphenylphosphine)gold(I) with borane tert-butylamine complex in the presence of 1,3-bis(diphenylphosphino)propane. Electrospray ionization was used to introduce the clusters into the gas-phase and mass-selection was employed to isolate a single ionic cluster species (Au11L53+, L = 1,3-bis(diphenylphosphino)propane) which was delivered to surfaces at well controlled kinetic energies. Using in-situ time of flight secondary ion mass spectrometry (TOF-SIMS) it is demonstrated that the Au11L53+ cluster retains its 3+ charge state when soft landed onto the surface of a 1H,1H,2H,2H-

Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

2012-01-24T23:59:59.000Z

145

Simple and inexpensive time-of-flight charge-to-mass analyzer for ion beam source characterization  

SciTech Connect

We describe the design, electronics, and test results of a simple and low-cost time-of-flight ion charge-to-mass analyzer that is suitable for ion source characterization. The method selects a short-time sample of the beam whose charge-to-mass composition is then separated according to ion velocity and detected by a remote Faraday cup. The analyzer is a detachable device that has been used for rapid analysis of charge-to-mass composition of ion beams accelerated by voltages of up to about 100 kV.

Gushenets, V. I.; Nikolaev, A. G.; Oks, E. M.; Vintizenko, L. G.; Yushkov, G. Yu.; Oztarhan, A.; Brown, I. G. [High Current Electronics Institute, Russian Academy of Sciences, 2/3 Akademichesky Avenue, Tomsk 634055 (Russian Federation); Ege University, Bornova-Izmir 35100 (Turkey); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2006-06-15T23:59:59.000Z

146

Mass-resolved retarding field energy analyzer and its measurement of ion energy distribution in helicon plasma  

E-Print Network (OSTI)

Mass-resolved retarding field energy analyzer and its measurement of ion energy distribution) are measured at rf power of 1000 W. The results show that the fairly broad energy distributions of different analyzer; Ion energy distribution; Helicon plasma 1. Introduction It is well recognized that ion

Zexian, Cao

147

Role of ion mass in the generation of fluctuations and poloidal flows in a simple toroidal plasma  

Science Conference Proceedings (OSTI)

Generation of fluctuations and poloidal flow is investigated in a simple toroidal plasma, at a given magnetic field strength for varying ion masses. Under similar discharge conditions, the fluctuation induced poloidal flux is found to decrease with increasing ion mass. Consequently, the absolute net poloidal flow velocity is found to scale down systematically with increase in the ion mass. The net poloidal flow in units of ion acoustic velocity is, however, comparable for all masses on the low field side and shows minor variations on the high field side. The frequency of the first harmonic in the density and potential power spectra is found to decrease with decreasing absolute net flow. A transition occurs in the fluctuation behavior from highly coherent state to a turbulent state with increase in the ion mass, from argon to xenon.

Goud, T. S.; Ganesh, R.; Saxena, Y. C.; Raju, D. [Institute for Plasma Research, Gandhinagar 382428 Gujarat (India)

2012-07-15T23:59:59.000Z

148

Brouwer's problem on a heavy particle in a rotating vessel: wave propagation, ion traps, and rotor dynamics  

E-Print Network (OSTI)

In 1918 Brouwer considered stability of a heavy particle in a rotating vessel. This was the first demonstration of a rotating saddle trap which is a mechanical analogue for quadrupole particle traps of Penning and Paul. We revisit this pioneering work in order to uncover its intriguing connections with classical rotor dynamics and fluid dynamics, stability theory of Hamiltonian and non-conservative systems as well as with the modern works on crystal optics and atomic physics. In particular, we find that the boundary of the stability domain of the undamped Brouwer's problem possesses the Swallowtail singularity corresponding to the quadruple zero eigenvalue. In the presence of dissipative and non-conservative positional forces there is a couple of Whitney umbrellas on the boundary of the asymptotic stability domain. The handles of the umbrellas form a set where all eigenvalues of the system are pure imaginary despite the presence of dissipative and non-conservative positional forces.

Oleg N. Kirillov

2010-12-04T23:59:59.000Z

149

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation: A Pseudoatomic Model of the COPII Cage Obtained from Cryo-Electron Microscopy and Mass Spectrometry,  

E-Print Network (OSTI)

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation ultrahigh-resolution 14.5 tesla Fourier transform ion cyclotron resonance mass spectrometry. The Mag

Weston, Ken

150

Ion exchange separation and mass spectrometric analysis of uranium for solutions containing plutonium  

SciTech Connect

An ion exchange technique separates plutonium from uranium using Dowex-1 resin and a methanol--HCl plutonium elutriant. The method is applicable to both trace uranium determination and uranium isotopic distribution analysis by mass spectrometry. Distribution coefficients for plutonium, and elution curves for uranium and plutonium are shown. For uranium analysis the percent relative standard deviation is 0.8 at 120-2400 micrograms uranium per gram plutonium and 5.0 at 5 micrograms uranium per gram plutonium. (auth)

McBride, K.C.

1975-06-01T23:59:59.000Z

151

Development of a variable-temperature ion mobility/ time-of-flight mass spectrometer for separation of electronic isomers  

E-Print Network (OSTI)

The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to demonstrate the ability to discriminate between electronic isomers. Ion mobility allows for the separation of ions based on differing cross-sections-to-charge ratio. This allows for the possible discrimination of species with same mass if the ions differ by cross-section. Time-offlight mass spectrometry was added to mass identify the separated peak for proper identification. A liquid nitrogen-cooled mobility cell was employed for a two-fold purpose. First, the low temperatures increase the peak resolution to aid in resolving the separated ions. This is necessary when isomers may have similar cross-sections. Second, low temperature shortens the mean free path and decreases the neutral buffer gas speeds allowing for more interactions between the ions and the drift gas. Kr2+ study was performed to verify instrument performance. The variable-temperature ion mobility spectrometer was utilized to separate the distonic and conventional ion forms of CH3OH, CH3F, and CH3NH2 and to discriminate between the keto and enol forms of the acetone radical cation. Density functional theory and ab initio calculations were employed to aid in proper identification of separating isomers. Monte Carlo integration tools were also developed to predict ion cross-section and resolution within a buffer gas.

Verbeck, Guido Fridolin

2006-05-01T23:59:59.000Z

152

Ion mass dependence of the etch yield of SrTiO{sub 3} films in reactive plasmas  

Science Conference Proceedings (OSTI)

The influence of the positive ion composition on the ion-assisted chemical etch yield of SrTiO{sub 3} films in Ar/SF{sub 6} plasmas is investigated using a parametric approach. The etch yield is found to decrease as the concentration fraction of molecular ions increases. Introducing the concept of effective mass for both ions and SrTiO{sub 3}, these experimental results are quantitatively explained in the framework of a well-established model originally developed to describe the sputtering of single-atom materials by noble monoatomic ions.

Langlois, O.; Stafford, L.; Margot, J.; Chaker, M. [Departement de Physique, Universite de Montreal, Montreal, Quebec (Canada); INRS-Energie, Materiaux et Telecommunications, Varennes, Quebec (Canada)

2005-09-26T23:59:59.000Z

153

Nuclear Physics with trapped  

E-Print Network (OSTI)

Nuclear Physics with trapped atoms and ions #12;2/2/2013Dan Melconian #12;2/2/2013Dan Melconian Outline · Scope and applications of nuclear physics precision frontier compliments LHC properties and aquifers in the Sahara #12;2/2/2013Dan Melconian What is Nuclear Physics? · Began with the study

Boas, Harold P.

154

EMSL: Capabilities: Mass Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

Five linear ion traps (one with ETD) Three triple-quadrupole spectrometers Three ion mobility spectrometry (IMS) - time-of-flight (TOF) spectrometers Seventeen custom HPLC,...

155

COLD TRAPS  

DOE Patents (OSTI)

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

Thompson, W.I.

1958-09-30T23:59:59.000Z

156

LC-IMS-MS Feature Finder: Detecting Multidimensional Liquid Chromatography, Ion Mobility, and Mass Spectrometry Features in Complex Datasets  

SciTech Connect

We introduce a command line software application LC-IMS-MS Feature Finder that searches for molecular ion signatures in multidimensional liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) data by clustering deisotoped peaks with similar monoisotopic mass, charge state, LC elution time, and ion mobility drift time values. The software application includes an algorithm for detecting and quantifying co-eluting chemical species, including species that exist in multiple conformations that may have been separated in the IMS dimension.

Crowell, Kevin L.; Slysz, Gordon W.; Baker, Erin Shammel; Lamarche, Brian L.; Monroe, Matthew E.; Ibrahim, Yehia M.; Payne, Samuel H.; Anderson, Gordon A.; Smith, Richard D.

2013-09-13T23:59:59.000Z

157

Inertial measurement via dynamics of trapped particles  

E-Print Network (OSTI)

We describe theoretical and practical aspects of the particle trap as an inertial sensor. The insight motivating this approach is that a trapped particle acts like a mass on a spring, but the restoring forces are provided ...

Post, E. Rehmi, 1966-

2003-01-01T23:59:59.000Z

158

Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter  

Science Conference Proceedings (OSTI)

The effect of ion mass and charge state on plasma transport through a 90{sup o}-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, ''self-bias'' resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a ''trough'' shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filter ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simply model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.

Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol; Anders, Andre

2003-12-01T23:59:59.000Z

159

B American Society for Mass Spectrometry( 2011 DOI: 10.1007/s13361-011-0179-8  

E-Print Network (OSTI)

A new instrument that combines ion mobility spectrometry (IMS) separations with tandem mass spectrometry in the mobility dimension. Here, we report the development of a new instrument that combines mobility separations Spectrom. (2011) 22:1477Y1485 RESEARCH ARTICLE An Ion Mobility/Ion Trap/Photodissociation Instrument

Clemmer, David E.

160

Gas-phase and Solution-phase Peptide Conformations Studied by Ion Mobility-mass Spectrometry and Molecular Dynamics Simulations  

E-Print Network (OSTI)

Ion mobility spectrometry (IMS) separates ions on the basis of ion-neutral collision cross-sections (CCS, [omega]), which are determined by the geometry or conformation of the ions. The size-based IM separation can be extended to distinguish conformers that have different shapes in cases where shape differences influence the accessible surface area of the molecule. In recent years, IM has rapidly evolved as a structural characterization technique, which has applied on various structural biology problems. In this work, IMS is combined with molecular dynamics simulation (MDS), specially the integrated tempering sampling molecular dynamics simulation (ITS-MDS) to explore the gas-phase conformation space of two molecular systems (i) protonated tryptophan zipper 1 (trpzip1) ions and its six derivatives (ii) alkali metal ion (Na, K and Cs) adducts of gramicidin A (GA). The structural distributions obtained from ITS-MDS are compared well with results obtained from matrix-assisted laser desorption ionization-ion mobility-mass spectrometry (MALDI-IM-MS) for trpzip 1 series and electrospray ionization-ion mobility-mass spectrometry (ESI-IM-MS) for alkali metal ion adducts of GA. Furthermore, the solvent dependence on conformational preferences of the GA dimer is investigated using a combination of mass spectrometry techniques, viz. ESI-IM-MS and hydrogen/deuterium exchange (HDX)-MS, and MDS. The IM experiments reveal three distinct gramicidin A species, detected as the sodium ion adduct ions, [2GA + 2Na]˛?, and the equilibrium abundances of the dimer ions varies with solvent polarity. The solution phase conformations are assigned as the parallel and anti-parallel [beta]-helix dimer, and the anti-parallel dimer is the preferred conformation in non-polar organic solvent. The calculated CCS profiles by ITS-MDS agree very well with the experimentally measured CCS profiles, which underscore the utility of the method for determining candidate structures as well as the relative abundances of the candidate structures. The benefit of combining ion mobility measurements with solution-phase H/D exchange is allowing identifications and detail analysis of the solution-phase subgroup conformations, which cannot be uncovered by one method alone.

Chen, Liuxi

2012-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Trapped Ions and Laser Cooling  

Science Conference Proceedings (OSTI)

... internal degree of freedom, could reduce the translational tem- perature of the gas if there were sufficient isola- tion from the rest of the environment. ...

2002-08-07T23:59:59.000Z

162

Mode trap  

DOE Patents (OSTI)

This report discusses a mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around it`s aperture and extending radially out toward it`s absorbing material layer.

Chojnacki, E.P.

1992-12-31T23:59:59.000Z

163

Study of heavy ion induced fission fragment angular and mass distribution at near and sub-coulomb barrier energies  

E-Print Network (OSTI)

The thesis presents investigations on the angular and mass distribution of fission fragments on heavy ion induced fission reactions. The present investigations address current issues in heavy ion induced fission reactions like finding the optimum entrance channel for the synthesis of super heavy elements (SHE). A double arm time of flight spectrometer over long flight path was used to measure the precise masses of complementary fission fragments. Necessary large area position sensitive gas detectors, the method of experiments and data analysis were developed. The first string of measurements were for a spherical target (209^Bi) with oxygen and fluorine projectiles. The next series of experiments were done using a deformed target (232^Th) with fluorine, oxygen and carbon projectiles.

T. K. Ghosh

2005-08-10T23:59:59.000Z

164

ION SOURCE  

DOE Patents (OSTI)

The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

Leland, W.T.

1960-01-01T23:59:59.000Z

165

COLD TRAP  

DOE Patents (OSTI)

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

Milleron, N.

1963-03-12T23:59:59.000Z

166

Development of A Cryogenic Drift Cell Spectrometer and Methods for Improving the Analytical Figures of Merit for Ion Mobility-Mass Spectrometry Analysis  

E-Print Network (OSTI)

A cryogenic (325-80 K) ion mobility-mass spectrometer was designed and constructed in order to improve the analytical figures-of-merit for the chemical analysis of small mass analytes using ion mobility-mass spectrometry. The instrument incorporates an electron ionization source, a quadrupole mass spectrometer, a uniform field drift cell spectrometer encased in a cryogenic envelope, and an orthogonal geometry time-of-flight mass spectrometer. The analytical benefits of low temperature ion mobility are discussed in terms of enhanced separation ability, ion selectivity and sensitivity. The distinction between resolving power and resolution for ion mobility is also discussed. Detailed experimental designs and rationales are provided for each instrument component. Tuning and calibration data and methods are also provided for the technique. Proof-of-concept experiments for an array of analytes including rare gases (argon, krypton, xenon), hydrocarbons (acetone, ethylene glycol, methanol), and halides (carbon tetrachloride) are provided in order to demonstrate the advantages and limitations of the instrument for obtaining analytically useful information. Trendline partitioning of small analyte ions based on chemical composition is demonstrated as a novel chemical analysis method. The utility of mobility-mass analysis for mass selected ions is also demonstrated, particularly for probing the ion chemistry which occurs in the drift tube for small mass ions. As a final demonstration of the separation abilities of the instrument, the electronic states of chromium and titanium (ground and excited) are separated with low temperature. The transition metal electronic state separations demonstrated here are at the highest resolution ever obtained for ion mobility methods. The electronic conformational mass isomers of methanol (conventional and distonic) are also partially separated at low temperature. Various drift gases (helium, neon, and argon) are explored for the methanol system in order to probe stronger ion-neutral interaction potentials and effectuate higher resolution separations of the two isomeric ions. Finally, two versatile ion source designs and a method for axially focusing ions at low pressure (1-10 torr) using electrostatic fields is presented along with some preliminary work on the ion sources.

May, Jody C.

2009-08-01T23:59:59.000Z

167

Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry  

SciTech Connect

The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T{sub e}) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n{sub e}) is in the range 10{sup 8}--10{sup 10} {sup {minus}cm }at the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} near the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10{sup 4}--10{sup 5} downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z{sup 2} intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z{sup 2} fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument.

Niu, Hongsen

1995-02-10T23:59:59.000Z

168

Extreme Chromatography: Faster, Hotter, SmallerChapter 6 Silver-ion High-performance Liquid Chromatography—Mass Spectrometry in the Analysis of Lipids  

Science Conference Proceedings (OSTI)

Extreme Chromatography: Faster, Hotter, Smaller Chapter 6 Silver-ion High-performance Liquid Chromatography—Mass Spectrometry in the Analysis of Lipids Methods and Analyses eChapters Methods - Analyses Books Downloadable pdf...

169

Ultrasensitive detection of radioactive cesium isotopes using a magneto-optical trap.  

SciTech Connect

We report the first magneto-optical trapping of mdioactive {sup 135}Cs and {sup 137}Cs and a promising means for detecting these isotopes to ullrasensilive lcvels by a system coupling the magneto-optical trap (MOT) to a mass separator. The mass separator efficiently delivers a 20 kV ion beam of either isotope into a quartzcube MOT cell having in one corner a small-diameter Zr foil, on which the ion beam is focused and into which the ions are implantetl. Inductive heating of thc foil releases {approx}45% of the implanted atoms into a MOT that uses large diameter beams and a dry-film coating to capture 3% of the released vapor. MOT fluorescence signals were found to increasc linearly with the number of foil-implanted atoms over a range of 10{sup 4} to 10{sup 7} in trapped-atom number. The measured slope of MOT signal versus number implanted was equal in the case each isotope to within 4%, signifying our ability to measure {sup 137}Cs/{sup 135}Cs ratios to within 4%. The isotopic selectivities of the mass separator and MOT combine to suppress interfering signal from {sup 133}Cs by a factor of greater than 5 x 10{sup 12} in the case of detecting {sup 135}Cs or {sup 137}Cs. Our present sample detection sensitivity is one million atoms.

Di Rosa, M. D. (Michael D.); Crane, S. G. (Scott G.); Kitten, J. J. (Jason J.); Taylor, W. A. (Wayne A.); Vieira, D. J. (David J.); Zhao, X. (Xinxin)

2002-01-01T23:59:59.000Z

170

The Radial Loss of Ions Trapped in the Thermal Barrier Potential and the Design of Divertor Magnetic Field in GAMMA10  

Science Conference Proceedings (OSTI)

The ion radial loss exists in the presence of a non-axisymmetric electrostatic potential in the end-mirror cells of GAMMA10, which leads to a formation of the thermal barrier potential. The non-axisymmetric electrostatic potential can also exist in the central cell. A design for divertor magnetic field of GAMMA10 is performed, the purpose of which is first to reduce an ion radial transport in the central cell by making electrostatic potential circular and second to assure the macroscopic plasma stability of GAMMA10 without help of non-axisymmetric anchor cells which enhances a neoclassical radial transport.

Katanuma, I. [Plasma Research Center, University of Tsukuba (Japan); Ito, T. [Plasma Research Center, University of Tsukuba (Japan); Saimaru, H. [Plasma Research Center, University of Tsukuba (Japan); Sasagawa, Y. [Plasma Research Center, University of Tsukuba (Japan); Pastukhov, V.P. [I.V.Kuruchatov Atomic Energy Institute (Russian Federation); Ishii, K. [Plasma Research Center, University of Tsukuba (Japan); Tatematsu, Y. [Plasma Research Center, University of Tsukuba (Japan); Saito, T. [Plasma Research Center, University of Tsukuba (Japan); Islam, Md.K. [Plasma Research Center, University of Tsukuba (Japan); Nakashima, Y. [Plasma Research Center, University of Tsukuba (Japan); Cho, T. [Plasma Research Center, University of Tsukuba (Japan)

2005-01-15T23:59:59.000Z

171

Mass-energy distribution of fragments within Langevin dynamics of fission induced by heavy ions  

SciTech Connect

A stochastic approach based on four-dimensional Langevin fission dynamics is applied to calculating mass-energy distributions of fragments originating from the fission of excited compound nuclei. In the model under investigation, the coordinate K representing the projection of the total angular momentum onto the symmetry axis of the nucleus is taken into account in addition to three collective shape coordinates introduced on the basis of the {l_brace}c, h, {alpha}{r_brace} parametrization. The evolution of the orientation degree of freedom (K mode) is described by means of the Langevin equation in the overdamped regime. The tensor of friction is calculated under the assumption of the reducedmechanismof one-body dissipation in the wall-plus-window model. The calculations are performed for two values of the coefficient that takes into account the reduction of the contribution from the wall formula: k{sub s} 0.25 and k{sub s} = 1.0. Calculations with a modified wall-plus-window formula are also performed, and the quantity measuring the degree to which the single-particle motion of nucleons within the nuclear system being considered is chaotic is used for k{sub s} in this calculation. Fusion-fission reactions leading to the production of compound nuclei are considered for values of the parameter Z{sup 2}/A in the range between 21 and 44. So wide a range is chosen in order to perform a comparative analysis not only for heavy but also for light compound nuclei in the vicinity of the Businaro-Gallone point. For all of the reactions considered in the present study, the calculations performed within four-dimensional Langevin dynamics faithfully reproduce mass-energy and mass distributions obtained experimentally. The inclusion of the K mode in the Langevin equation leads to an increase in the variances of mass and energy distributions in relation to what one obtains from three-dimensional Langevin calculations. The results of the calculations where one associates k{sub s} with the measure of chaoticity in the single-particle motion of nucleons within the nuclear system under study are in good agreement for variances of mass distributions. The results of calculations for the correlations between the prescission neutron multiplicity and the fission-fragment mass, Left-Pointing-Angle-Bracket n{sub pre}(M) Right-Pointing-Angle-Bracket , and between, this multiplicity and the kinetic energy of fission fragments, Left-Pointing-Angle-Bracket n{sub pre}(E{sub k}) Right-Pointing-Angle-Bracket , are also presented.

Anischenko, Yu. A., E-mail: yuri.anischenko@gmail.com; Adeev, G. D. [Omsk State University (Russian Federation)

2012-08-15T23:59:59.000Z

172

Secondary ions mass spectroscopy measurements of dopant impurities in highly stressed InGaN laser diodes  

Science Conference Proceedings (OSTI)

We performed a systematic secondary ions mass spectroscopy (SIMS) study of dopant impurities in life-time stressed InGaN laser devices in order to investigate the main degradation mechanism that is observed in nitride laser diodes. A continuous wave (cw) current density of 3 kA/cm{sup 2} was applied to InGaN laser diodes over an extended period of time and we observed the characteristic square root degradation of optical power. We compared the SIMS profiles of Mg, H, and Si impurities in the aged devices and observe that the impurities are remarkably stable over 10 000 h of cw operation. Nor is there any SIMS evidence of p-contact metals penetrating into the semiconductor material. Thus our SIMS results are contrary to what one would expect for impurity diffusion causing the observed square root degradation characteristic.

Marona, L.; Suski, T. [Institute of High Pressure Physics, Sokolowska 29/37, 01-142 Warsaw (Poland); Perlin, P.; Czernecki, R.; Leszczynski, M.; Bockowski, M. [Institute of High Pressure Physics, Sokolowska 29/37, 01-142 Warsaw (Poland); TopGaN Ltd., Sokolowska 29/37, 01-142 Warsaw (Poland); Jakiela, R. [Institute of Physics, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Najda, S. P. [TopGaN Ltd., Sokolowska 29/37, 01-142 Warsaw (Poland)

2011-06-13T23:59:59.000Z

173

Evidence of microscopic effects in fragment mass distribution in heavy ion induced fusion-fission reactions  

E-Print Network (OSTI)

Our measurements of variances ($\\sigma_{m}^2$) in mass distributions of fission fragments from fusion-fission reactions of light projectiles (C, O and F) on deformed thorium targets exhibit a sharp anomalous increase with energy near the Coulomb barrier, in contrast to the smooth variation of $\\sigma_{m}^2$ for the spherical bismuth target. This departure from expectation based on a statistical description is explained in terms of microscopic effects arising from the orientational dependence in the case of deformed thorium targets.

T. K. Ghosh; S. Pal; K. S. Gold; P. Bhattacharya

2005-06-27T23:59:59.000Z

174

Negative-mass Instability in Nonlinear Plasma Waves  

SciTech Connect

The negative-mass instability (NMI), previously found in ion traps, appears as a distinct regime of the sideband instability in nonlinear plasma waves with trapped particles. As the bounce frequency of these particles decreases with the bounce action, bunching can occur if the action distribution is inverted in trapping islands. In contrast to existing theories that also infer instabilities from the anharmonicity of bounce oscillations, spatial periodicity of the islands turns out to be unimportant, and the particle distribution can be unstable even if it is at at the resonance. An analytical model is proposed which describes both single traps and periodic nonlinear waves and concisely generalizes the conventional description of the sideband instability in plasma waves. The theoretical results are supported by particle-in-cell simulations carried out for a regime accentuating the NMI effect.

I.Y. Dodin, P.F. Schmit, J. Rocks and N.J. Fisch

2013-01-30T23:59:59.000Z

175

External Mass Injection to Reduce Energetic Ion Production in the Discharge Plume of High Current Hollow Cathodes  

E-Print Network (OSTI)

flow Voltage Spread (V) Volt at Max Ion Energy (V) Externalfor 10 sccm cathode flow. Volt at Max Ion Energy (V) 16 sccm10 sccm cathode 10 sccm injected Volt at Max Ion Energy (V)

Chu, Emily

2012-01-01T23:59:59.000Z

176

A new detector setup for ISOLTRAP and test of the Isobaric Multiplet Mass Equation  

E-Print Network (OSTI)

Installed at the on-line isotope separator ISOLDE at CERN, the tandem Penning-trap spectrometer ISOLTRAP is designed to perform high-accuracy mass measurements on short-lived radionuclides. Based on the determination of the ion cyclotron frequency $\

Yazidjian, Chabouh; Ban, Gilles

2006-01-01T23:59:59.000Z

177

Loading a planar RF Paul Trap from a cold Yb? source  

E-Print Network (OSTI)

In this thesis, we demonstrate a functioning planar radio frequency, three-rod Paul Trap, loaded with Yb+ ions that have been photoionized from a source of neutral atoms, which were cooled in a magneto-optical trap. Planar ...

Shields, Brendan John

2006-01-01T23:59:59.000Z

178

Nano-Domain Analysis Via Massive Cluster Secondary Ion Mass Spectrometry in the Event-by-Event Mode  

E-Print Network (OSTI)

Secondary ion mass spectrometry (SIMS) is a surface analysis technique which characterizes species sputtered by an energetic particle beam. Bombardment with cluster projectiles offers the following notable advantages over bombardment with atomic ions or small clusters: enhanced emission of molecular ions, low damage cross-section, and reduced molecular fragmentation. Additionally, in the case of Au4004 and C60 impacts, desorption originates from nanometric volumes. These features make clusters useful probes to obtain molecular information from both nano-objects and nano-domains. The "event-by-event bombardment/detection mode" probes nano-objects one-at-a-time, while collecting and storing the corresponding secondary ion (SI) information. Presented here are the first experiments where free-standing nano-objects were bombarded with keV projectiles of atomic to nanoparticle size. The objects are aluminum nano-whiskers, 2 nm in diameter and ~250 nm in length. Au4004 has a diameter of ~2 nm, comparable to the nominal diameter of the nanowhiskers. There are notable differences in the SI response from sample volumes too small for full projectile energy deposition. The whisker spectra are dominated by small clusters?the most abundant species being AlO- and AlO2-. Bulk samples have larger yields for AlO2- than for AlO-, while this trend is reversed in whisker samples. Bulk samples give similar abundances of large SI clusters, while whisker samples give an order of magnitude lower yield of these SIs. Effective yields were calculated in order to determine quantitative differences between the nano-objects and bulk samples. The characterization of individual nano-objects from a mixture is demonstrated with negatively charged polymer spheres that are attracted to and retained by the nano-whiskers. The spheres are monodisperse polystyrene nanoparticles (30nm diameter). Our results show that the event-by-event mode can provide information on the nature, size, relative location, and abundance of nano-objects in the field of view. This study presents the first evidence of quantitative molecular information originating from nano-object mixtures. Biologically relevant systems (solid-supported lipid bilayers) were also characterized using Au5 , Au4004 and C60 . Organization-dependent SI emission was observed for phosphocholine bilayers. Lipid domain formation was also investigated in bilayers formed from cholesterol and a mixed lipid system. Trends in the correlation coefficient suggest that cholesterol segregates from the surrounding lipid environment during raft formation.

Pinnick, Veronica Tiffany

2009-12-01T23:59:59.000Z

179

Linear trap with three orthogonal quadrupole fields for dust charging experiments  

SciTech Connect

Investigations of charging processes on a single dust grain under controlled conditions in laboratory experiments are the unique way to understand the behavior of dust grains in complex plasma (in space, in laboratory, or in technological applications). An electrodynamic trap is often utilized for both holding a single grain and continuously measuring its charge-to-mass ratio. We propose a modified design of the linear quadrupole trap with the electrodes split into two parts; each of them being supplied by a designated source. The paper presents basic calculations and the results of the trap prototype tests. These tests have confirmed our expectations and have shown that the suggested solution is fully applicable for the dust charging experiments. The uncertainty of determination of the dust grain charge does not exceed 10{sup -3}. The main advantages of the suggested design in comparison with other traps used for dust investigations can be summarized as: The trap (i) is more opened, thus it is suitable for a simultaneous application of the ion and electron beams and UV source; (ii) facilitates investigations of dust grains in a broader range of parameters; and (iii) allows the grain to move along the axis in a controlled way.

Beranek, Martin; Nemecek, Zdenek; Safrankova, Jana; Jerab, Martin; Pavlu, Jiri [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Cermak, Ivo [CGC Instruments, Chemnitz (Germany)

2012-11-15T23:59:59.000Z

180

Steam Trap Application  

E-Print Network (OSTI)

The effective application of steam traps encompasses three primary areas which are the selection and sizing, the installation, and the monitoring of the steam trapping system. Proper application of steam traps will improve production rates, product quality, and reduce energy and maintenance costs.

Murphy, J. J.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Coverage Dependent Charge Reduction of Cationic Gold Clusters on Surfaces Prepared Using Soft Landing of Mass-selected Ions  

Science Conference Proceedings (OSTI)

The ionic charge state of monodisperse cationic gold clusters on surfaces may be controlled by selecting the coverage of mass-selected ions soft landed onto a substrate. Polydisperse diphosphine-capped gold clusters were synthesized in solution by reduction of chloro(triphenylphosphine)gold(I) with borane tert-butylamine in the presence of 1,3-bis(diphenylphosphino)propane. The polydisperse gold clusters were introduced into the gas phase by electrospray ionization and mass selection was employed to select a multiply charged cationic cluster species (Au11L53+, m/z = 1409, L = 1,3-bis(diphenylphosphino)propane) which was delivered to the surfaces of four different self-assembled monolayers on gold (SAMs) at coverages of 1011 and 1012 clusters/mm2. Employing the spatial profiling capabilities of in-situ time-of-flight secondary ion mass spectrometry (TOF-SIMS) it is shown that, in addition to the chemical functionality of the monolayer (as demonstrated previously: ACS Nano, 2012, 6, 573) the coverage of cationic gold clusters on the surface may be used to control the distribution of ionic charge states of the soft-landed multiply charged clusters. In the case of a 1H,1H,2H,2H-perfluorodecanethiol SAM (FSAM) almost complete retention of charge by the deposited Au11L53+ clusters was observed at a lower coverage of 1011 clusters/mm2. In contrast, at a higher coverage of 1012 clusters/mm2, pronounced reduction of charge to Au11L52+ and Au11L5+ was observed on the FSAM. When soft landed onto 16- and 11-mercaptohexadecanoic acid surfaces on gold (16,11-COOH-SAMs), the mass-selected Au11L53+ clusters exhibited partial reduction of charge to Au11L52+ at lower coverage and additional reduction of charge to both Au11L52+ and Au11L5+ at higher coverage. The reduction of charge was found to be more pronounced on the surface of the shorter (thinner) C11 than the longer (thicker) C16-COOH-SAM. On the surface of the 1-dodecanethiol (HSAM) monolayer, the most abundant charge state was found to be Au11L52+ at lower coverage and Au11L5+ at higher coverage, respectively. A coverage-dependent electron tunneling mechanism is proposed to account for the observed reduction of charge of mass-selected multiply charged gold clusters soft landed on SAMs. The results demonstrate that one of the critical parameters that influence the chemical and physical properties of supported metal clusters, ionic charge state, may be controlled by selecting the coverage of charged species soft landed onto surfaces.

Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

2012-11-29T23:59:59.000Z

182

THE COUPLED EVOLUTION OF ELECTRONS AND IONS IN CORONAL MASS EJECTION-DRIVEN SHOCKS  

SciTech Connect

We present simulations of coronal mass ejections (CMEs) performed with a new two-temperature coronal model developed at the University of Michigan, which is able to address the coupled thermodynamics of the electron and proton populations in the context of a single fluid. This model employs heat conduction for electrons, constant adiabatic index ({gamma} = 5/3), and includes Alfven wave pressure to accelerate the solar wind. The Wang-Sheeley-Arge empirical model is used to determine the Alfven wave pressure necessary to produce the observed bimodal solar wind speed. The Alfven waves are dissipated as they propagate from the Sun and heat protons on open magnetic field lines to temperatures above 2 MK. The model is driven by empirical boundary conditions that includes GONG magnetogram data to calculate the coronal field, and STEREO/EUVI observations to specify the density and temperature at the coronal boundary by the Differential Emission Measure Tomography method. With this model, we simulate the propagation of fast CMEs and study the thermodynamics of CME-driven shocks. Since the thermal speed of the electrons greatly exceeds the speed of the CME, only protons are directly heated by the shock. Coulomb collisions low in the corona couple the protons and electrons allowing heat exchange between the two species. However, the coupling is so brief that the electrons never achieve more than 10% of the maximum temperature of the protons. We find that heat is able to conduct on open magnetic field lines and rapidly propagates ahead of the CME to form a shock precursor of hot electrons.

Manchester IV, W. B.; Van der Holst, B.; Toth, G.; Gombosi, T. I. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

2012-09-01T23:59:59.000Z

183

Microfabricated ion frequency standard  

DOE Patents (OSTI)

A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

Schwindt, Peter (Albuquerque, NM); Biedermann, Grant (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Stick, Daniel L. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Olsson, III, Roy H. (Albuquerque, NM)

2010-12-28T23:59:59.000Z

184

Extending the frontiers of mass spectrometric instrumentation and methods  

SciTech Connect

The focus of this dissertation is two-fold: developing novel analysis methods using mass spectrometry and the implementation and characterization of a novel ion mobility mass spectrometry instrumentation. The novel mass spectrometry combines ion trap for ion/ion reactions coupled to an ion mobility cell. The long term goal of this instrumentation is to use ion/ion reactions to probe the structure of gas phase biomolecule ions. The three ion source - ion trap - ion mobility - qTOF mass spectrometer (IT - IM - TOF MS) instrument is described. The analysis of the degradation products in coal (Chapter 2) and the imaging plant metabolites (Appendix III) fall under the methods development category. These projects use existing commercial instrumentation (JEOL AccuTOF MS and Thermo Finnigan LCQ IT, respectively) for the mass analysis of the degraded coal products and the plant metabolites, respectively. The coal degradation paper discusses the use of the DART ion source for fast and easy sample analysis. The sample preparation consisted of a simple 50 fold dilution of the soluble coal products in water and placing the liquid in front of the heated gas stream. This is the first time the DART ion source has been used for analysis of coal. Steven Raders under the guidance of John Verkade came up with the coal degradation projects. Raders performed the coal degradation reactions, worked up the products, and sent them to me. Gregg Schieffer developed the method and wrote the paper demonstrating the use of the DART ion source for the fast and easy sample analysis. The plant metabolite imaging project extends the use of colloidal graphite as a sample coating for atmospheric pressure LDI. DC Perdian and I closely worked together to make this project work. Perdian focused on building the LDI setup whereas Schieffer focused on the MSn analysis of the metabolites. Both Perdian and I took the data featured in the paper. Perdian was the primary writer of the paper and used it as a chapter in his dissertation. Perdian and Schieffer worked together to address the revisions and publish it in Rapid Communications in Mass Spectrometry Journal.

Schieffer, Gregg

2010-12-15T23:59:59.000Z

185

Evaluating Steam Trap Performance  

E-Print Network (OSTI)

Laboratory tests were conducted on several types of steam traps at Holston Defense Corporation in Kingsport, Tennessee. Data from these tests, which determined their relative efficiencies, were used in performing economic analyses to determine their equivalent uniform annual cost (EUAC). The comparison was made using a computer program written for the Apple II computer to evaluate overall steam trap economics. This program calculates the EUAC for any steam trap based on 12 input variables including capital, maintenance and steam costs, interest rate and trap life. After determinIng the EUAC, the program will perform sensitivity analyses on any of the twelve variables. (This computer program is available from the author.) This study shows that inverted bucket traps have lower EUAC's under more conditions than other types of traps. Also, this study shows that live steam loss is the heaviest contributor to the annual operating cost of any steam trap and that maintenance frequency and repair cost are also more important than a trap's first cost.

Fuller, N. Y.

1986-06-01T23:59:59.000Z

186

Argon Cleaning Helps Trapped Ions Chill Out  

Science Conference Proceedings (OSTI)

... This cleaning process is similar to bead-blasting or a stream of water, but is relatively gentle. It removes the atoms in a layer-by-layer fashion. ...

2012-09-05T23:59:59.000Z

187

LASER INDUCED FLUORESCENCE OF TRAPPED MOLECULAR IONS  

E-Print Network (OSTI)

by Phil Eggers) produces a ttl signal with the same periodelectrical drawing. The ttl signal from this circuit (termedthe R.F. ttl) along with the pulse indicating when it is

Grieman, Frederick Joseph.

2010-01-01T23:59:59.000Z

188

Quantum Logic with a Few Trapped Ions  

Science Conference Proceedings (OSTI)

... The Schrodinger equation must therefore be intergrated numerically to evaluate the amplitudes of all these energy levels. ...

2002-11-14T23:59:59.000Z

189

Quantum state manipulation of trapped atomic ions  

Science Conference Proceedings (OSTI)

... Jones, RR, Raman, CS, Schumacher, SW & Bucksbaum, PH 1993 Phys. ... Turchette, QA, Hood, C., Lange, W., Mabushi, H. & Kimble, HJ 1995 Phys. ...

2002-08-13T23:59:59.000Z

190

Microwave quantum logic gates for trapped ions  

Science Conference Proceedings (OSTI)

... for universal quantum information processing, because any unitary operation on ... Gordan coefficients, we predict a 97% repumping efficiency to j"ć ...

2011-08-18T23:59:59.000Z

191

LASER INDUCED FLUORESCENCE OF TRAPPED MOLECULAR IONS  

E-Print Network (OSTI)

System Laser Power Measurement Wavelength Calibration SystemLaser Power Measurement Wavelength Calibration PAGE Fluorescence Detection Systemmeasurement system. The actual time for initiation of the detection gate with respect to the laser

Grieman, Frederick Joseph.

2010-01-01T23:59:59.000Z

192

Charge trapping in imidazolium ionic liquids  

NLE Websites -- All DOE Office Websites (Extended Search)

trapping in imidazolium ionic liquids trapping in imidazolium ionic liquids I. A. Shkrob and J. F. Wishart J. Phys. Chem. B 113, 5582-5592 (2009). [Find paper at ACS Publications] or use ACS Articles on Request Abstract: Room-temperature ionic liquids (ILs) are a promising class of solvents for applications ranging from photovoltaics to solvent extractions. Some of these applications involve the exposure of the ILs to ionizing radiation, which stimulates interest in their radiation and photo- chemistry. In the case of ILs consisting of 1,3-dialkylimidazolium cations and hydrophobic anions, ionization, charge transfer and redox reactions yield charge-trapped species thought to be radicals resulting from neutralization of the constituent ions. Using computational chemistry methods and the recent results on electron spin resonance (ESR) and transient absorption

193

Impurity ions in a rotating tokamak  

SciTech Connect

It is pointed out that the impurity ions in rotating toroidal plasmas tend to behave like trapped particles. That may explain the observed fact.

Yoshikawa, S.

1980-10-01T23:59:59.000Z

194

Steam trap monitor  

DOE Patents (OSTI)

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

Ryan, M.J.

1987-05-04T23:59:59.000Z

195

Development of matrix assisted laser desorption ionization-ion mobility-orthogonal time-of-flight mass spectrometry as a tool for proteomics  

E-Print Network (OSTI)

Separations coupled to mass spectrometry (MS) are widely used for large-scale protein identification in order to reduce the adverse effects of analyte ion suppression, increase the dynamic range, and as a deconvolution technique for complex datasets typical of cellular protein complements. In this work, matrix assisted laser desorption-ionization is coupled with ion mobility (IM) separation for the analysis of biological molecules. The utility of liquid-phase separations coupled to MS lies in the orthogonality of the two separation dimensions for all analytes. The data presented in this work illustrates that IM-MS relies on the correlation between separation dimensions for different classes (either structural or chemical) of analyte ions to obtain a useful separation. For example, for a series of peptide ions of increasing mass-to-charge (m/z) a plot drift time in the IM drift cell vs. m/z increases in a near-linear fashion, but DNA or lipids having similar m/z values will have very different IM drift time-m/z relationships, thus drift time vs. m/z can be used as a qualitative tool for compound class identification. In addition, IM-MS is applied to the analysis of large peptide datasets in order to determine the peak capacity of the method for bottom-up experiments in proteomics, and it is found that IM separation increases the peak capacity of an MS-only experiment by a factor of 5-10. The population density of the appearance area for peptides is further characterized in terms of the gas-phase structural propensities for tryptic peptide ions. It is found that a small percentage (~3%) of peptide sequences form extended (i.e., helical or ?-sheet type) structures in the gas-phase, thus influencing the overall appearance area for peptide ions. Furthermore, the ability of IM-MS to screen for the presence of phosphopeptides is characterized, and it is found that post translationally modified peptides populate the bottom one-half to one-third of the total appearance area for peptide ions. In general, the data presented in this work indicates that IM-MS offers dynamic range and deconvolution capabilities comparable to liquid-phase separation techniques coupled to MS on a time scale (ms) that is fully compatible to current MS, including TOF-MS, technology.

Ruotolo, Brandon Thomas

2003-05-01T23:59:59.000Z

196

Laser ablation-inductively coupled plasma-mass spectrometry: Examinations of the origins of polyatomic ions and advances in the sampling of particulates  

SciTech Connect

This dissertation provides a general introduction to Inductively coupled plasma-mass spectrometry (ICP-MS) and laser ablation (LA) sampling, with an examination of analytical challenges in the employment of this technique. It discusses the origin of metal oxide ions (MO+) in LA-ICP-MS, as well as the effect of introducing helium and nitrogen to the aerosol gas flow on the formation of these polyatomic interferences. It extends the study of polyatomic ions in LA-ICP-MS to metal argide (MAr+) species, an additional source of possible significant interferences in the spectrum. It describes the application of fs-LA-ICP-MS to the determination of uranium isotope ratios in particulate samples.

Witte, Travis

2011-11-30T23:59:59.000Z

197

Effect of trapping in degenerate quantum plasmas  

SciTech Connect

In the present work we consider the effect of trapping as a microscopic process in a plasma consisting of quantum electrons and nondegenerate ions. The formation of solitary structures is investigated in two cases: first when the electrons are fully degenerate and second when small temperature effects are taken into account. It is seen that not only rarefactive but coupled rarefactive and compressive solitons are obtained under different temperature conditions.

Shah, H. A.; Qureshi, M. N. S. [Department of Physics, GC University, Lahore 54000 (Pakistan); Tsintsadze, N. [Department of Physics, GC University, Lahore 54000 (Pakistan); Salam Chair, GC University, Lahore 54000 (Pakistan)

2010-03-15T23:59:59.000Z

198

Venus Fly Trap Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Venus Fly Trap Experiment Venus Fly Trap Experiment Name: Jeremy Bailey Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A Question: My name is Jeremy Bailey, and I am a student of Dorseyville Middle School. I have been working on a science project about Venus' Fly Traps. A recent addition to the project involved designing an experiment about something I found interesting about them. However, I don't know where to get them or how to grow them in the moderate climate of Pittsburgh. Also, I don't know how a successful experiment could be designed. Replies: Jeremy, I believe Venus Fly traps can be found 'in the wild' in the coastal floodplain of the Carolinas. As far as where to buy them, look in the phonebook yellow pages under plants or houseplants and do some calling. I live in eastern Pennsylvania, and over here they even sell them in hardware stores like Hechinger's and Home Depot (in their garden departments). I don't think you will have luck trying to grow them outside, our winters here are a bit too harsh for them. From what I recall they require substantial moisture and more moderate climes. You might try looking for houseplant books at your local library for more detailed information.

199

Steam trap monitor  

DOE Patents (OSTI)

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

Ryan, Michael J. (Plainfield, IL)

1988-01-01T23:59:59.000Z

200

WATER-TRAPPED WORLDS  

Science Conference Proceedings (OSTI)

Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO{sub 2} as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

Menou, Kristen [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Gravity-induced resonances in a rotating trap  

E-Print Network (OSTI)

It is shown that in an anisotropic harmonic trap that rotates with the properly chosen rotation rate, the force of gravity leads to a resonant behavior. Full analysis of the dynamics in an anisotropic, rotating trap in 3D is presented and several regions of stability are identified. On resonance, the oscillation amplitude of a single particle, or of the center of mass of a many-particle system (for example, BEC), grows linearly with time and all particles are expelled from the trap. The resonances can only occur when the rotation axis is tilted away from the vertical position. The positions of the resonances (there are always two of them) do not depend on the mass but only on the characteristic frequencies of the trap and on the direction of the angular velocity of rotation.

Iwo Bialynicki-Birula; Tomasz Sowinski

2004-12-01T23:59:59.000Z

202

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network (OSTI)

An investigation of the sympathetic cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted.Molecular dynamics simulations are performed to study the rf heating mechanisms in the ion trap. The dependence of rf heating rates on the ion temperature, trapping parameters, and the number of ions is obtained. New rf heating mechanism affecting ultra-cold ion clouds exposed to laser radiation is described.The saturation spectroscopy setup of the hyperfine spectra of the molecular iodine has been built to provide an accurate frequency reference for the laser wavelength. This reference is used to obtain the fluorescence lineshapes of the laser cooled Mg$^+$ ions under different trapping conditions.The ion temperatures are deduced from the measurements, and the influence of the rf heating rates on the fluorescence lineshapes is also discussed. Cooling of the heavy ($m=720$a.u.) fullerene ions to under 10K by the means of the sympathetic cooling by the Mg$^+$ ions($m=24$a.u.) is demonstrated. The single-photon imaging system has been developed and used to obtain the images of the Mg$^+$ ion crystal structures at mK temperatures.

Ryjkov, Vladimir Leonidovich

2003-12-01T23:59:59.000Z

203

Microchip and wedge ion funnels and planar ion beam analyzers using same  

DOE Patents (OSTI)

Electrodynamic ion funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective ion focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and ion mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, "wedge" funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress ion beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

Shvartsburg, Alexandre A; Anderson, Gordon A; Smith, Richard D

2012-10-30T23:59:59.000Z

204

Final Technical Report for DE-FG02-06ER15835: Chemical Imaging with 100nm Spatial Resolution: Combining High Resolution Flurosecence Microscopy and Ion Mobility Mass Spectrometry  

SciTech Connect

We have combined, in a single instrument, high spatial resolution optical microscopy with the chemical specificity and conformational selectivity of ion mobility mass spectrometry. We discuss the design and construction of this apparatus as well as our efforts in applying this technique to thin films of molecular semiconductor materials.

Buratto, Steven K. [UC Santa Barbara

2013-09-03T23:59:59.000Z

205

DNA Separation Using Photoelectrophoretic Traps  

SciTech Connect

In our recent publications we presented a design that allows formation of highly localized and optically controlled electrophoretic traps. 1,2 We demonstrated that electrophoretic traps can be utilized for biomolecule photoconcentration, optically directed transport, and separation by size. 1,2 In the current publication we suggest a hybrid design for biomolecule separation which implements electrophoretic traps in tandem with well-established electrophoretic techniques. We perform Monte Carlo simulations that demonstrate that the resolution of well-established electrophoretic techniques can be greatly enhanced by introducing photoelectrophoretic traps.

Braiman, Avital [ORNL; Thundat, Thomas George [ORNL; Rudakov, Fedor M [ORNL

2011-01-01T23:59:59.000Z

206

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally...

207

Design and performance of a combined secondary ion mass spectrometry-scanning probe microscopy instrument for high sensitivity and high-resolution elemental three-dimensional analysis  

Science Conference Proceedings (OSTI)

State-of-the-art secondary ion mass spectrometry (SIMS) instruments allow producing 3D chemical mappings with excellent sensitivity and spatial resolution. Several important artifacts however arise from the fact that SIMS 3D mapping does not take into account the surface topography of the sample. In order to correct these artifacts, we have integrated a specially developed scanning probe microscopy (SPM) system into a commercial Cameca NanoSIMS 50 instrument. This new SPM module, which was designed as a DN200CF flange-mounted bolt-on accessory, includes a new high-precision sample stage, a scanner with a range of 100 {mu}m in x and y direction, and a dedicated SPM head which can be operated in the atomic force microscopy (AFM) and Kelvin probe force microscopy modes. Topographical information gained from AFM measurements taken before, during, and after SIMS analysis as well as the SIMS data are automatically compiled into an accurate 3D reconstruction using the software program 'SARINA,' which was developed for this first combined SIMS-SPM instrument. The achievable lateral resolutions are 6 nm in the SPM mode and 45 nm in the SIMS mode. Elemental 3D images obtained with our integrated SIMS-SPM instrument on Al/Cu and polystyrene/poly(methyl methacrylate) samples demonstrate the advantages of the combined SIMS-SPM approach.

Wirtz, Tom; Fleming, Yves; Gerard, Mathieu [Department 'Science and Analysis of Materials' (SAM), Centre de Recherche Public, Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Gysin, Urs; Glatzel, Thilo; Meyer, Ernst [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Wegmann, Urs [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Maier, Urs [Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Odriozola, Aitziber Herrero; Uehli, Daniel [SPECS Zurich GmbH, Technoparkstr. 1, CH-8005 Zuerich (Switzerland)

2012-06-15T23:59:59.000Z

208

Physica Scripta. Vol. T22, 228-237, 1988. Summary of the Physics in Traps Panel  

E-Print Network (OSTI)

astrophysics, potential condensed matter experiments, and new ideas for optical and magnetic traps for neutral measured [7] their mass difference in a commercial spec- trometer (with cubic trap) to % 1 part in IO4dependence of the correction terms, one can clearly see the advantage of performing the experi- ment

California at San Diego, University of

209

Electric-dipole 5s - 5p Transitions in Promethiumlike Ions  

SciTech Connect

The 5s-5p electric-dipole resonance transitions in highly ionized promethiumlike ions have been studied applying relativistic multi-reference Moeller-Plesset second-order perturbation theory. The transition wavelengths are determined to within 0.2 {angstrom} in the more highly charged ions, where the level degeneracies are small. For somewhat lighter ions a very large reference space was used in order to account for the many degeneracies. In order to calculate transition probabilities and lifetimes, correlation corrections have been added to the transition operator in the next order. The contributions from the higher orders of the theory, that is, frequency-dependent Breit correction, Lamb shift, and mass shifts, have been estimated. The results are used to re-assess spectroscopic data from beam-foil, electron beam ion trap, and tokamak observations.

Vilkas, M J; Ishikawa, Y; Tr?bert, E

2008-02-29T23:59:59.000Z

210

First Attempts at Antihydrogen Trapping in ALPHA  

SciTech Connect

The ALPHA apparatus is designed to produce and trap antihydrogen atoms. The device comprises a multifunction Penning trap and a superconducting, neutral atom trap having a minimum-B configuration. The atom trap features an octupole magnet for transverse confinement and solenoidal mirror coils for longitudinal confinement. The magnetic trap employs a fast shutdown system to maximize the probability of detecting the annihilation of released antihydrogen. In this article we describe the first attempts to observe antihydrogen trapping.

Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Cesar, C. L.; Lambo, R.; Silveira, D. M. [Instituto de Fisica Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Fujiwara, M. C. [TRIUMF, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3 (Canada)] (and others)

2008-08-08T23:59:59.000Z

211

Trapped Quintessential Inflation  

E-Print Network (OSTI)

Quintessential inflation is studied using a string modulus as the inflaton - quintessence field. The modulus begins its evolution at the steep part of its scalar potential, which is due to non-perturbative effects (e.g. gaugino condensation). It is assumed that the modulus crosses an enhanced symmetry point (ESP) in field space. Particle production at the ESP temporarily traps the modulus resulting in a brief period of inflation. More inflation follows, due to the flatness of the potential, since the ESP generates either an extremum (maximum or minimum) or a flat inflection point in the scalar potential. Eventually, the potential becomes steep again and inflation is terminated. After reheating the modulus freezes due to cosmological friction at a large value, such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions or other effects. The modulus remains frozen until the present, when it can become quintessence and account for the dark energy necessary to explain the observed accelerated expansion.

J. C. Bueno Sanchez; K. Dimopoulos

2006-05-26T23:59:59.000Z

212

Volatiles trapped in coals: Second quarterly report  

SciTech Connect

We have been able to collect and characterize volatiles that are evolved in the grinding of coal. We have developed a very sensitive method for collecting volatiles evolved in grinding. A sealed, gas tight, grinding apparatus has been built. With this system we can collect volatiles freed from the coal matrix during grinding. To do this a 125 cm/sup 3/ sample of coal is placed in to a 1 liter sealable ball mill jar. The jar is evacuated and the coal ground for 1 hr. The jar is then removed from the ball mill and evacuated into our sample collection system. Gas from the jar is pumped through two stages of dust filtering into a liquid nitrogen cold trap charged with 5 ml of methylene chloride. After warming the trap is shaken so that any gas from the sample mixes with and dissolves in the methylene chloride. One microliter samples of the methylene chloride are injected into a Finnegan GCMS. Preliminary analysis of mass spectra from peaks in the RIC show the presence of hydrocarbons. It was possible to definitively identify cyclohexene. The total amount of hydrocarbons seen is low. The attached figure is the mass spectra of the cyclohexene that was collected from the ground coal. 1 fig.

Sutter, J.R.; Halpern, J.B.

1988-01-01T23:59:59.000Z

213

The Scattering of Long Coastal-Trapped Waves in Frictional Seas  

Science Conference Proceedings (OSTI)

The scattering of coastal-trapped waves (CTWs) by a region of irregular shelf bathymetry is determined from a circulation integral of the depth-integrated momentum equations. For relatively weak stratification the conservation of geostrophic mass ...

John F. Middleton; Mark A. Merrifield

1995-04-01T23:59:59.000Z

214

Long-term drifts of stray electric fields in a Paul trap  

E-Print Network (OSTI)

We investigate the evolution of quasi-static stray electric fields in a linear Paul trap over a period of several months. Depending on how these electric fields are initially induced we observe very different time scales for the field drifts. Photo-induced electric fields decay on time scales of days. We interpret this as photo-electrically generated charges on insulating materials which decay via discharge currents. In contrast, stray fields due to the exposure of the ion trap to a beam of Ba atoms mainly exhibit slow dynamics on the order of months. We explain this observation as a consequence of a coating of the trap electrodes by the atomic beam. This may lead to contact potentials which can slowly drift over time due to atomic diffusion and chemical processes on the surface. In order not to perturb the field evolutions, we suppress the generation of additional charges and atomic coatings in the Paul trap during the measurements. For this, we shield the ion trap from ambient light and only allow the use of near-infrared lasers. Furthermore, we minimize the flux of atoms into the ion trap chamber. Long-term operation of our shielded trap led us to a regime of very low residual electric field drifts of less than 0.03 V/m per day.

Arne Härter; Artjom Krükow; Andreas Brunner; Johannes Hecker Denschlag

2013-05-29T23:59:59.000Z

215

Inspect and Repair Steam Traps  

SciTech Connect

This revised ITP tip sheet on inspecting and repairing steam traps provide how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

216

Electronic Trap States in Methanofullerenes  

E-Print Network (OSTI)

The trap states in three fullerene derivatives, namely PC61BM ([6,6]-phenyl C61 butyric acid methyl ester), bisPC61BM (bis[6,6]-phenyl C61 butyric acid methyl ester) and PC71BM ([6,6]-phenyl C71 butyric acid methyl ester), are investigated by thermally stimulated current measurements (TSC). Thereby, the lower limit of the trap densities for all studied methanofullerenes exhibits values in the order of 10^22 m^-3 with the highest trap density in bisPC61BM and the lowest in PC61BM. Fractional TSC measurements on PC61BM reveal a broad trap distribution instead of discrete trap levels with activation energies ranging from 15 meV to 270 meV and the maximum at about 75 meV. The activation energies of the most prominent traps in the other two fullerene derivatives are significantly higher, being at 96 meV and 223 meV for PC71BM and 184 meV for bisPC61BM, respectively. The influence of these findings on the performance of organic solar cells is discussed.

Julia Schafferhans; Carsten Deibel; Vladimir Dyakonov

2011-07-18T23:59:59.000Z

217

PHYSICAL REVIEW A 84, 022343 (2011) Coherence of a qubit stored in Zeeman levels of a single optically trapped atom  

E-Print Network (OSTI)

experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 52 S1/2, F = 1 hyperfine ground level of a single optically trapped 87 Rb atom. Larmor precession of a single and the quantum repeater [1]. There, ground states of trapped atoms or ions are ideal candidates

Weinfurter, Harald

218

Field reversed ion rings  

DOE Green Energy (OSTI)

In typical field-reversed ion ring experiments, an intense annular ion beam is injected across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Assuming the characteristic ionization time is much shorter than the long ({ital t}{approx_gt}2{pi}/{Omega}{sub {ital i}}) beam evolution time scale, we investigate the formation of an ion ring in the background plasma followed by field reversal, using a 21/2-D hybrid, PIC code FIRE, in which the beam and background ions are treated as particles and the electrons as a massless fluid. We show that beam bunching and trapping occurs downstream in a ramped magnetic field for an appropriate set of experimental parameters. We find that a compact ion ring is formed and a large field reversal {zeta}={delta}{ital B}/{ital B}{approx_gt}1 on axis develops. We also observe significant deceleration of the ring on reflection due to the transfer of its axial momentum to the background ions, which creates favorable trapping conditions. {copyright} {ital 1995 American Institute of Physics.}

Sudan, R.N.; Omelchenko, Y.A. [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)

1995-09-01T23:59:59.000Z

219

Investigation of the effect of intra-molecular interactions on the gas-phase conformation of peptides as probed by ion mobility-mass spectrometry, gas-phase hydrogen/deuterium exchange, and molecular mechanics  

E-Print Network (OSTI)

Ion mobility-mass spectrometry (IM-MS), gas-phase hydrogen/deuterium (H/D) exchange ion molecule reactions and molecular modeling provide complimentary information and are used here for the characterization of peptide ion structure, including fine structure detail (i.e., cation-? interactions, ?-turns, and charge solvation interactions). IM-MS experiments performed on tyrosine containing tripeptides show that the collision cross-sections of sodiated, potassiated and doubly sodiated species of gly-gly-tyr are smaller than that of the protonated species, while the cesiated and doubly cesiated species are larger. Conversely, all of the alkali-adducted species of try-gly-gly have collision cross-sections that are larger than that of the protonated species. The protonated and alkali metal ion adducted (Na+, K+ and Cs+) species of bradykinin and bradykinin fragments 1-5, 1-6, 1-7, 1-8, 2-7, 5-9 and 2-9 were also studied using IM-MS and the alkali metal ion adducts of these species were found to have cross-sections very close to those of the protonated species. Additionally, multiple peak features observed in the ATDs of protonated bradykinin fragments 1-5, 1-6 and 1-7 are conserved upon alkali metal ion adduction. It was observed from gas-phase H/D ion molecule reactions that alkali adducted species exchange slower and to a lesser extent than protonated species in the tyrosine- and arginine-containing peptides. Experimental and computational results are discussed in terms of peptide ion structure, specifically the intra-molecular interactions present how those interactions change upon alkali salt adduction, as well as with the sequence of the peptide. Additionally, IM-MS data suggests the presence of a compact conformation of bradykinin fragment 1-5 (RPPGF) when starting from organic solvent conditions. As water is added stepwise to methanolic solutions, a more extended conformation is populated. When the starting solution is composed of ?90% water, two distinct mobility profiles are observed as well as a shoulder, indicating the presence of three gas-phase conformations for RPPGF. Gas-phase H/D exchange of [M+H]+ ions prepared from aqueous solvents show a bi-exponential decay, whereas samples prepared from organic solvents show a single exponential decay. The effect of solvent on gas-phase peptide ion structure, i.e., solution-phase memory effects, is discussed and gas-phase structures are compared to know solution-phase structures.

Sawyer, Holly Ann

2004-12-01T23:59:59.000Z

220

Single event mass spectrometry  

DOE Patents (OSTI)

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Conzemius, Robert J. (Ames, IA)

1990-01-16T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
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221

Method for calibrating mass spectrometers  

DOE Patents (OSTI)

A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

2002-12-24T23:59:59.000Z

222

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

223

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

224

Electron multiplier-ion detector system  

DOE Patents (OSTI)

This patent relates to an improved ion detector for use in mass spectrometers for pulse counting signal ions which may have a positive or a negative charge. The invention combines a novel electron multiplier with a scintillator type of ion detector. It is a high vacuum, high voltage device intended for use in ion microprobe mass spectrometers. (auth)

Dietz, L.A.

1975-08-01T23:59:59.000Z

225

TRImP - A new facility to produce and trap radioactive isotopes  

E-Print Network (OSTI)

At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) 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 production target station and a dual magnetic separator installed and commissioned. We will slow down the isotopes of interest using an ion catcher and in a further stage a radiofrequency quadropole gas cooler (RFQ). The isotopes will finally be trapped in an atomic trap for precision studies.

Sohani, M

2006-01-01T23:59:59.000Z

226

TRImP - A new facility to produce and trap radioactive isotopes  

E-Print Network (OSTI)

At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) 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 production target station and a dual magnetic separator installed and commissioned. We will slow down the isotopes of interest using an ion catcher and in a further stage a radiofrequency quadropole gas cooler (RFQ). The isotopes will finally be trapped in an atomic trap for precision studies.

M. Sohani

2006-01-17T23:59:59.000Z

227

Electronuclear ion fusion in an ion cyclotron resonance reactor  

DOE Patents (OSTI)

A method and apparatus for generating nuclear fusion by ion cyclotron resonance in an ion trap reactor. The reactor includes a cylindrical housing having an axial axis, an internal surface, and first and second ends. First and second end plates that are charged are respectively located at the first and second ends of the cylindrical housing. A gas layer is adsorbed on the internal surface of the cylindrical housing. Ions are desorbed from the gas layer, forming a plasma layer adjacent to the cylindrical housing that includes first ions that have a same charge sign as the first and second end plates. A uniform magnetic field is oriented along the axial axis of the cylindrical housing. Second ions, that are unlike the first ions, but have the same charge sign, are injected into the cylindrical housing along the axial axis of the cylindrical housing. A radio frequency field resonantly accelerates the injected second ions at the cyclotron resonance frequency of the second ions. The second ions circulate in increasing helical orbits and react with the first ions, at the optimum energy for nuclear fusion. The amplitude of the radio frequency field is adjusted to accelerate the second ions at a rate equal to the rate of tangential energy loss of the second ions by nuclear scattering in the first ions, causing the ions to continually interact until fusion occurs.

Cowgill, Donald F.

1996-12-01T23:59:59.000Z

228

Long-term drifts of stray electric fields in a Paul trap  

E-Print Network (OSTI)

We investigate the evolution of stray electric fields in a linear Paul trap over a period of several months. We demonstrate a way to clearly distinguish between the two main sources of these fields, namely insulated charged up patches and patch charges originating from contact potentials. To achieve high sensitivity in these measurements, we operate the trap in a way that strongly suppresses the generation of additional patch charges. For this, we shield the ion trap from ambient light and only allow the use of near-infrared lasers. Furthermore, we minimize additional contaminations of the trap electrodes by minimizing the flux of atoms into the ion trap chamber. We find that photo-induced electric fields decay on time scales of days. In contrast, stray fields due to contamination-induced contact potentials on trap electrodes mainly exhibit slow dynamics on the order of months, probably dominated by diffusion and slow chemical processes. Long-term operation of our shielded trap led us to a regime of very low ...

Härter, Arne; Brunner, Andreas; Denschlag, Johannes Hecker

2013-01-01T23:59:59.000Z

229

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

230

Trapped-flux superconducting memory  

Science Conference Proceedings (OSTI)

A memory cell based on trapped flux in superconductors has been built and tested. The cell is constructed entirely by vacuum evaporation of thin films and can be selected by coincident current or by other techniques, with drive-current requirements less ...

J. W. Crowe

1957-10-01T23:59:59.000Z

231

Soliton propagation, reflection, and transmission in an inhomogeneous plasma with trapped electrons  

Science Conference Proceedings (OSTI)

Transmission and reflection of solitons from a semitransparent grid in an inhomogeneous plasma in the presence of trapped electrons is studied analytically. Conditions are obtained for the obliqueness of the propagation and the drift velocity of ions for the soliton transmission and reflection. Also, a transmission-reflection conservation law is derived. The contribution of trapped electrons to the solitons' propagation and their reflection and transmission is examined through energy, amplitude, and width of the solitons, in addition to the effect of temperature and drift of the ions.

Aziz, Farah; Malik, Hitendra K.; Stroth, Ulrich [Institut fuer Plasmaforschung, Universitaet Stuttgart, 70569 Stuttgart (Germany)

2011-04-15T23:59:59.000Z

232

HEAVY ION LINEAR ACCELERATOR  

DOE Patents (OSTI)

A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

Van Atta, C.M.; Beringer, R.; Smith, L.

1959-01-01T23:59:59.000Z

233

Long-Wave Trapping by Oceanic Ridges  

Science Conference Proceedings (OSTI)

Long waves are affected by bottom topography and under certain conditions may be trapped along topographical contours which then act as wave guides transmitting wave energy for great distances with little loss. This study examines waves trapped ...

Richard Paul Shaw; Wayne Neu

1981-10-01T23:59:59.000Z

234

A Neutrally Buoyant, Upper Ocean Sediment Trap  

Science Conference Proceedings (OSTI)

The authors have designed and deployed a neutrally buoyant sediment trap (NBST) intended for use in the upper ocean. The aim was to minimize hydrodynamic flow interference by making a sediment trap that drifted freely with the ambient current. ...

James R. Valdes; James F. Price

2000-01-01T23:59:59.000Z

235

Determination of Hydrogen Peak Temperatures and Trapping ...  

Science Conference Proceedings (OSTI)

Presentation Title, Determination of Hydrogen Peak Temperatures and Trapping Energies of Various Lattice Defects In Iron Using Thermal Desorption ...

236

Capturing Energy Savings with Steam Traps  

E-Print Network (OSTI)

This paper will discuss the energy savings potential of steam traps and present the energy, economic, and environmental reason why an active steam trap maintenance program is good for the company's bottom line. Several case studies will be discussed to demonstrate the merits of steam trap technology.

Bockwinkel, R. G.; French, S. A.

1997-04-01T23:59:59.000Z

237

The Elimination of Steam Traps  

E-Print Network (OSTI)

How would you like to have a share of $154,000,000,000 a year? According to the Department of Energy that is roughly what was spent for creating steam in 1978. Steam generation accounts for fully one half of the industrial and commercial energy dollar. That figure could be reduced by 10-20% or more by the simple elimination of steam traps. Recent engineering developments show that steam traps can be eliminated. Documented results demonstrate that the retrofitting of existing facilities to alternative methods of condensate removal is simple and economically feasible, with paybacks of less than 12 months. Advantages obtained in the first year remain consistent for several years after conversion with virtual elimination of maintenance.

Dickman, F.

1985-05-01T23:59:59.000Z

238

Laser ion source development at Holifield Radioactive Ion Beam Facility  

Science Conference Proceedings (OSTI)

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:sapphire lasers for nuclear physics and astrophysics research at Holifield Radioactive Ion Beam Facility. Three Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Y.; Havener, C. C.; Beene, J. R. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Gottwald, T.; Mattolat, C.; Vane, C. R.; Wendt, K. [Institute of Physics, University of Mainz, D-55099 Mainz (Germany); Howe, J. Y.; Kiggans, J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2012-02-15T23:59:59.000Z

239

Effect of trapping in a degenerate plasma in the presence of a quantizing magnetic field  

SciTech Connect

Effect of trapping as a microscopic phenomenon in a degenerate plasma is investigated in the presence of a quantizing magnetic field. The plasma comprises degenerate electrons and non-degenerate ions. The presence of the quantizing magnetic field is discussed briefly and the effect of trapping is investigated by using the Fermi-Dirac distribution function. The linear dispersion relation for ion acoustic wave is derived in the presence of the quantizing magnetic field and its influence on the propagation characteristics of the linear ion acoustic wave is discussed. Subsequently, fully nonlinear equations for ion acoustic waves are used to obtain the Sagdeev potential and the investigation of solitary structures. The formation of solitary structures is studied both for fully and partially degenerate plasmas in the presence of a quantizing magnetic field. Both compressive and rarefactive solitons are obtained for different conditions of temperature and magnetic field.

Shah, H. A.; Iqbal, M. J.; Qureshi, M. N. S. [Department of Physics, GC University, Lahore 54000 (Pakistan); Tsintsadze, N. [Department of Physics, GC University, Lahore 54000 (Pakistan); Institute of Physics, Tbilisi 0177 (Georgia); Masood, W. [Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

2012-09-15T23:59:59.000Z

240

Integration of Micro-Optics with Ion Traps towards Efficient ...  

Science Conference Proceedings (OSTI)

... Al 100nm Au 500nm SiN 500nm Resistor Capacitor Bonding pads ... Challenges: • To minimize scattering loss super-polished surfaces at the fiber tip ...

2011-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Near-term Prospects for Trapped-Ion Quantum Simulation  

Science Conference Proceedings (OSTI)

... In conjunction with W. Lybarger, Jr. at LANL NIST NIST Sandia ... Jeremy Sage Andrew “Jamie” Kerman LANL Warren E. Lybarger, Jr. Page 22. ...

2011-03-01T23:59:59.000Z

242

New Ion Trap May Lead to Large Quantum Computers  

Science Conference Proceedings (OSTI)

... promising candidates for use as quantum bits (qubits) in quantum computers. ... all the basic building blocks for a quantum computer, including key ...

2013-08-07T23:59:59.000Z

243

5. Neutralization and Trapping of a Na Ion Beam  

E-Print Network (OSTI)

- Zn2+ 3EW8 1.80 M344 D101L Zn2+ 3EWF 2.50 Substrate H143A Zn2+ 3EZP 2.65 M344 D101N Zn2+ 3EZT 2.85 M

Groningen, Rijksuniversiteit

244

Secondary ion collection and transport system for ion microprobe  

DOE Patents (OSTI)

A secondary ion collection and transport system, for use with an ion microprobe, which is very compact and occupies only a small working distance, thereby enabling the primary ion beam to have a short focal length and high resolution. Ions sputtered from the target surface by the primary beam's impact are collected between two arcuate members having radii of curvature and applied voltages that cause only ions within a specified energy band to be collected. The collected ions are accelerated and focused in a transport section consisting of a plurality of spaced conductive members which are coaxial with and distributed along the desired ion path. Relatively high voltages are applied to alternate transport sections to produce accelerating electric fields sufficient to transport the ions through the section to an ion mass analyzer, while lower voltages are applied to the other transport sections to focus the ions and bring their velocity to a level compatible with the analyzing apparatus.

Ward, James W. (Canoga Park, CA); Schlanger, Herbert (Simi Valley, CA); McNulty, Jr., Hugh (Santa Monica, CA); Parker, Norman W. (Camarillo, CA)

1985-01-01T23:59:59.000Z

245

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.

McComas, D.J.; Nordholt, J.E.

1992-12-01T23:59:59.000Z

246

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

McComas, David J. (Los Alamos, NM); Nordholt, Jane E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

247

Revolutionary systems for catalytic combustion and diesel catalytic particulate traps.  

DOE Green Energy (OSTI)

This report is a summary of an LDRD project completed for the development of materials and structures conducive to advancing the state of the art for catalyst supports and diesel particulate traps. An ancillary development for bio-medical bone scaffolding was also realized. Traditionally, a low-pressure drop catalyst support, such as a ceramic honeycomb monolith, is used for catalytic reactions that require high flow rates of gases at high-temperatures. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. ''Robocasting'' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low-pressure drops. These alternative 3-dimensional geometries may also provide a foundation for the development of self-regenerating supports capable of trapping and combusting soot particles from a diesel engine exhaust stream. This report describes the structures developed and characterizes the improved catalytic performance that can result. The results show that, relative to honeycomb monolith supports, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application. Practical applications include the combustion of natural gas for power generation, production of syngas, and hydrogen reforming reactions. The robocast lattice structures also show practicality for diesel particulate trapping. Preliminary results for trapping efficiency are reported as well as the development of electrically resistive lattices that can regenerate the structure by combusting the trapped soot. During this project an ancillary bio-medical application was discovered for lattices of hydroxyapatite. These structures show promise as bone scaffolds for the reparation of damaged bone. A case study depicting the manufacture of a customized device that fits into a damaged mandible is described.

Stuecker, John Nicholas; Witze, Peter O.; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

2004-12-01T23:59:59.000Z

248

Model for hydrogen isotope backscattering, trapping and depth profiles in C and a-Si  

DOE Green Energy (OSTI)

A model of low energy hydrogen trapping and backscattering in carbon and a-silicon is described. Depth profiles are calculated and numerical results presented for various incident angular and energy distributions. The calculations yield a relation between depth profiles and the incident ion energy distribution. The use of this model for tokamak plasma diagnosis is discussed.

Cohen, S.A.; McCracken, G.M.

1979-03-01T23:59:59.000Z

249

Finite beta and resonant electron effects on trapped-electron instabilities  

SciTech Connect

Finite $beta$ (plasma pressure/magnetic pressure) and resonant electron effects on the dissipative trapped-electron instabilities are analyzed. These modifications are shown to have a strong stabilizing influence on the finite ion gyroradius and electron temperature gradient driven modes, respectively. For relevant tokamak parameters complete stabilization may be possible. Stability criteria for radially local and nonlocal cases are presented. (auth)

Tang, W.M.; Liu, C.S.; Rosenbluth, M.N.; Catto, P.J.; Callen, J.D.

1975-10-01T23:59:59.000Z

250

Texas A&M Penning Trap Facility - Design of the Measurement Trap  

E-Print Network (OSTI)

A tandem Penning trap facility has been designed and is under construction at the Texas A&M University Cyclotron Institute (TAMU-TRAP). The initial experimental program will be the study of correlation parameters for T=2 superallowed beta-delayed proton emitters. The measurement trap is a unique large-bore optimized 5-electrode cylindrical Penning trap, which features a 90 mm free radius, larger than in any existing Penning trap. This novel geometry allows for full radial containment of decay products of interest. The trap has also been designed to exhibit a "tunable" and "orthogonalized" geometry, which is useful for alternate experiments.

Mehlman, M; Shidling, P D

2012-01-01T23:59:59.000Z

251

Texas A&M Penning Trap Facility - Design of the Measurement Trap  

E-Print Network (OSTI)

A tandem Penning trap facility has been designed and is under construction at the Texas A&M University Cyclotron Institute (TAMU-TRAP). The initial experimental program will be the study of correlation parameters for T=2 superallowed beta-delayed proton emitters. The measurement trap is a unique large-bore optimized 5-electrode cylindrical Penning trap, which features a 90 mm free radius, larger than in any existing Penning trap. This novel geometry allows for full radial containment of decay products of interest. The trap has also been designed to exhibit a "tunable" and "orthogonalized" geometry, which is useful for alternate experiments.

M. Mehlman; D. Melconian; P. D. Shidling

2012-08-20T23:59:59.000Z

252

Trapping Rydberg Atoms in an Optical Lattice  

Science Conference Proceedings (OSTI)

Rubidium Rydberg atoms are laser excited and subsequently trapped in a one-dimensional optical lattice (wavelength 1064 nm). Efficient trapping is achieved by a lattice inversion immediately after laser excitation using an electro-optic technique. The trapping efficiency is probed via analysis of the trap-induced shift of the two-photon microwave transition 50S{yields}51S. The inversion technique allows us to reach a trapping efficiency of 90%. The dependence of the efficiency on the timing of the lattice inversion and on the trap laser power is studied. The dwell time of 50D{sub 5/2} Rydberg atoms in the lattice is analyzed using lattice-induced photoionization.

Anderson, S. E.; Younge, K. C.; Raithel, G. [FOCUS Center, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-12-23T23:59:59.000Z

253

Laser-Cooled Lithium Atoms: A New Source for Focused Ion Beams  

E-Print Network (OSTI)

Laser-Cooled Lithium Atoms: A New Source for Focused Ion Beams P R O J E C T L E A D E R : Jabez Mc E N T S Designed and constructed a laser-cooled, magneto-optical trap-based lithium ion source mounted on a commercial focused ion beam system, creating the world's first lithium ion microscope

Magee, Joseph W.

254

Trapping and Measuring Charged Particles in Liquids  

Genome sequencing especially benefits from the nanoscale approach. The trap is a three-layer, three-dimensional crossing metal/insulator structure.

255

Trapping and Measuring Charged Particles in Liquids  

Using molecular dynamics simulations, the researchers found that particles are trapped in liquid environments when appropriate AC/DC electric fields ...

256

Ion source  

DOE Patents (OSTI)

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01T23:59:59.000Z

257

Ultrasensitive Identification of Localization Variants of Modified Peptides Using Ion Mobility Spectrometry  

Science Conference Proceedings (OSTI)

Localization of the modification sites on peptides is challenging, particularly when multiple modifications or mixtures of localization isomers (variants) are involved. Such variants commonly coelute in liquid chromatography and may be undistinguishable in tandem mass spectrometry (MS/MS) for lack of unique fragments. Here, we have resolved the variants of singly and doubly phosphorylated peptides employing drift tube ion mobility spectrometry (IMS) coupled to time-of-flight mass spectrometry. Even with a moderate IMS resolving power of ~80, substantial separation was achieved for both 2+ and 3+ ions normally generated by electrospray ionization, including for the variant indistinguishable by MS/MS. Variants often exhibit a distribution of 3-D conformers, which can be adjusted for optimum IMS separation by prior field heating of ions in a funnel trap. The peak assignments were confirmed using MS/MS after IMS separation, but known species could be identified using just the ion mobility "tag". Avoiding the MS/MS step lowers the detection limit of localization variants to electron transfer dissociation in an Orbitrap MS.

Ibrahim, Yehia M.; Shvartsburg, Alexandre A.; Smith, Richard D.; Belov, Mikhail E.

2011-05-28T23:59:59.000Z

258

Energy trapping and shock disintegration in a composite granular medium  

E-Print Network (OSTI)

Granular materials demonstrate a strongly nonlinear behavior influencing the wave propagation in the medium. We report the first experimental observation of impulse energy confinement and the resultant disintegration of shock and solitary waves. The medium consists of alternating ensambles of high-modulus vs orders of magnitude lower modulus chains of different masses. The trapped energy is contained within the "softer" portions of the composite chain and is slowly released in the form of weak, separated pulses over an extended period of time. This effect is enhanced by using a specific group assembly and superimposed force.

C. Daraio; V. F. Nesterenko; E. B. Herbold; S. Jin

2005-09-24T23:59:59.000Z

259

Ion Funnel and Related Technology for Improved Sensitivity ...  

Search PNNL. PNNL Home; About; Research; Publications; Jobs; News; Contacts; Ion Funnel and Related Technology for Improved Sensitivity in Mass ...

260

Ion Removal  

INL’s ion removal technology leverages the ability of phosphazene polymers discriminate between water and metal ions, which allows water to pass ...

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Parameter exploration of optically trapped liquid aerosols  

E-Print Network (OSTI)

When studying the motion of optically trapped particles on the $\\mu s$ time scale, in low viscous media such as air, inertia cannot be neglected. Resolution of unusual and interesting behaviour not seen in colloidal trapping experiments is possible. In attempt to explain the phenomena we use power spectral methods to perform a parameter study of the Brownian motion of optically trapped liquid aerosol droplets concentrated around the critically damped regime. We present evidence that the system is suitably described by a simple harmonic oscillator model which must include a description of Fax\\'{e}n's correction, but not necessarily frequency dependent hydrodynamic corrections to Stokes' law. We also provide results describing how the system behaves under several variables and discuss the difficulty in decoupling the parameters responsible for the observed behaviour. We show that due to the relatively low dynamic viscosity and high trap stiffness it is easy to transfer between over- and under-damped motion by experimentally altering either trap stiffness or damping. Our results suggest stable aerosol trapping may be achieved in under-damped conditions, but the onset of deleterious optical forces at high trapping powers prevents the probing of the upper stability limits due to Brownian motion.

D. R. Burnham; P. J. Reece; D. McGloin

2009-07-27T23:59:59.000Z

262

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

McComas, D.J.; Nordholt, J.E.

1991-03-29T23:59:59.000Z

263

Deep traps in nonpolar m-plane GaN grown by ammonia-based molecular beam epitaxy  

Science Conference Proceedings (OSTI)

Deep level defects in nonpolar m-plane GaN grown by ammonia-based molecular beam epitaxy were characterized using deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS) and compared with polar c-plane GaN that was grown simultaneously in the same growth run. Significant differences in both the levels present and their concentrations were observed upon comparison of both growth orientations. DLTS revealed electron traps with activation energies of 0.14 eV, 0.20 eV, and 0.66 eV in the m-plane material, with concentrations that were {approx}10-50 x higher than traps of similar activation energies in the c-plane material. Likewise, DLOS measurements showed {approx}20 x higher concentrations of both a C{sub N} acceptor-like state at E{sub C} - 3.26 eV, which correlates with a high background carbon concentration observed by secondary ion mass spectroscopy for the m-plane material [A. Armstrong, A. R. Arehart, B. Moran, S. P. DenBaars, U. K. Mishra, J. S. Speck, and S. A. Ringel, Appl. Phys. Lett. 84, 374 (2004)], and the V{sub Ga}-related state level at E{sub C} - 2.49 eV, which is consistent with an enhanced yellow luminescence observed by photoluminescence. The findings suggest a strong impact of growth dynamics on the incorporation of impurities and electrically active native point defects as a function of GaN growth plane polarity.

Zhang, Z.; Arehart, A. R. [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Hurni, C. A.; Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106-5050 (United States); Yang, J. [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Myers, R. C.; Ringel, S. A. [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2012-01-30T23:59:59.000Z

264

FEMP-FTA--Steam Trap Performance Assessment  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Steam Trap Function Steam Trap Function Steam traps are automatic valves used in every steam system to remove conden- sate, air, and other non-condensable gases while preventing or minimizing the passing of steam. If condensate is allowed to collect, it reduces the flow capacity of steam lines and the thermal capacity of heat transfer equipment. In addition, excess condensate can lead to "water hammer," with potentially destructive and dangerous results. Air that remains after system startup reduces steam pressure and temperature and may also reduce the thermal capacity of heat transfer equipment. Non-condensable gases, such as oxygen and carbon dioxide, cause corrosion. Steam that passes through the trap provides no heating ser- vice. This effectively reduces the heating capacity

265

Laser cooling and trapping of neutral atoms*  

Science Conference Proceedings (OSTI)

... 1 m/s, any gas in equilibrium (other than spin-polarized atomic hydro- ... lattice-trapped atoms, a physical picture with the simplicity and power of the ...

2010-08-23T23:59:59.000Z

266

Trapping of strangelets in the geomagnetic field  

E-Print Network (OSTI)

Strangelets coming from the interstellar medium (ISM) are an interesting target to experiments searching for evidence of this hypothetic state of hadronic matter. We entertain the possibility of a {\\it trapped} strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the ISM flux (up to two orders of magnitude) due to quasi-stable trapping.

L. Paulucci; J. E. Horvath; G. A. Medina-Tanco

2007-07-22T23:59:59.000Z

267

Trapping of strangelets in the geomagnetic field  

Science Conference Proceedings (OSTI)

Strangelets arriving from the interstellar medium are an interesting target for experiments searching for evidence of this hypothetical state of hadronic matter. We entertain the possibility of a trapped strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely, having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the interstellar medium flux (up to 2 orders of magnitude) due to quasistable trapping.

Paulucci, L.; Horvath, J. E.; Medina-Tanco, G. A. [Instituto de Fisica-Universidade de Sao Paulo, Rua do Matao, Travessa R, 187, 05508-090, Cidade Universitaria, Sao Paulo SP (Brazil); Instituto de Astronomia, Geofisica e Ciencias Atmosfericas-Universidade de Sao Paulo, Rua do Matao, 1226, 05508-900, Cidade Universitaria, Sao Paulo SP (Brazil); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico A.P. 70-543, C.U. Mexico D.F. (Mexico)

2008-02-15T23:59:59.000Z

268

Trapping of strangelets in the geomagnetic field  

E-Print Network (OSTI)

Strangelets coming from the interstellar medium (ISM) are an interesting target to experiments searching for evidence of this hypothetic state of hadronic matter. We entertain the possibility of a {\\it trapped} strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the ISM flux (up to two orders of magnitude) due to quasi-stable trapping.

Paulucci, L; Medina-Tanco, G A

2007-01-01T23:59:59.000Z

269

Shale gas is natural gas trapped inside  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Shale gas is natural gas trapped inside formations of shale - fine grained sedimentary rocks that can be rich sources of petroleum and natural gas. Just a few years ago, much of...

270

Deconstruction of Activity-Dependent Covalent Modification of Heme in Human Neutrophil Myeloperoxidase by Multistage Mass Spectrometry (MS[superscript 4])  

SciTech Connect

Myeloperoxidase (MPO) is known to be inactivated and covalently modified by treatment with hydrogen peroxide and agents similar to 3-(2-ethoxypropyl)-2-thioxo-2,3-dihydro-1H-purin-6(9H)-one (1), a 254.08 Da derivative of 2-thioxanthine. Peptide mapping by liquid chromatography and mass spectrometry detected modification by 1 in a labile peptide-heme-peptide fragment of the enzyme, accompanied by a mass increase of 252.08 Da. The loss of two hydrogen atoms was consistent with mechanism-based oxidative coupling. Multistage mass spectrometry (MS{sup 4}) of the modified fragment in an ion trap/Orbitrap spectrometer demonstrated that 1 was coupled directly to heme. Use of a 10 amu window delivered the full isotopic envelope of each precursor ion to collision-induced dissociation, preserving definitive isotopic profiles for iron-containing fragments through successive steps of multistage mass spectrometry. Iron isotope signatures and accurate mass measurements supported the structural assignments. Crystallographic analysis confirmed linkage between the methyl substituent of the heme pyrrole D ring and the sulfur atom of 1. The final orientation of 1 perpendicular to the plane of the heme ring suggested a mechanism consisting of two consecutive one-electron oxidations of 1 by MPO. Multistage mass spectrometry using stage-specific collision energies permits stepwise deconstruction of modifications of heme enzymes containing covalent links between the heme group and the polypeptide chain.

Geoghegan, Kieran F.; Varghese, Alison H.; Feng, Xidong; Bessire, Andrew J.; Conboy, James J.; Ruggeri, Roger B.; Ahn, Kay; Spath, Samantha N.; Filippov, Sergey V.; Conrad, Steven J.; Carpino, Philip A.; Guimarăes, Cristiano R.W.; Vajdos, Felix F. (Pfizer)

2013-03-07T23:59:59.000Z

271

Thick-film technology for ultra high vacuum interfaces of micro-structured traps  

E-Print Network (OSTI)

We adopt thick-film technology to produce ultra high vacuum compatible interfaces for electrical signals. These interfaces permit voltages of hundreds of Volts and currents of several Amperes and allow for very compact vacuum setups, useful in quantum optics in general, and especially for quantum information and quantum simulations using miniaturized traps for ions or neutral atoms. Such printed circuits can also be useful as pure in-vacuum devices. We demonstrate a specific interface, which provides eleven current feedthroughs, more than 70 dc feedthroughs and a feedthrough for radio frequencies. We achieve a pressure in the low 1e-11mbar range and demonstrate the full functionality of the interface by trapping chains of cold ytterbium ions, which requires all of the signals mentioned above being present. In addition, a versatile multi-channel device for supplying precise time-dependent voltages has been developed.

Delia Kaufmann; Thomas Collath; M. Tanveer Baig; Peter Kaufmann; Eman Asenwar; Michael Johanning; Christof Wunderlich

2011-07-20T23:59:59.000Z

272

Analysis of electron dynamics in non-ideal Penning traps  

Science Conference Proceedings (OSTI)

Penning traps that are used for particular applications, such as in ion pump technology, Larmor, bouncing, and diocotron frequencies, can be of the same order of magnitude. The paper deals with the dynamics of electrons confined in such devices starting from the study of the properties of the trajectories. In cases of interest, in which electron-neutral collision frequency is much smaller with respect to the characteristic frequencies of the motion, suitable time averages of the trajectories are introduced in order to simplify the analysis of the problem. In the work, time averages have been calculated in a simple way by using an approximate r-z decoupling of the effective potential. Results obtained with the method are presented and discussed in both linear and nonlinear regimes.

Coppa, G.; Mulas, R. [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); D'Angola, A. [Dipartimento di Ingegneria e Fisica dell'Ambiente, Universita della Basilicata, 85100 Potenza (Italy)

2012-06-15T23:59:59.000Z

273

High resolution mass spectrometry method and system for analysis of whole proteins and other large molecules  

DOE Patents (OSTI)

A matrix assisted laser desorption/ionization (MALDI) method and related system for analyzing high molecular weight analytes includes the steps of providing at least one matrix-containing particle inside an ion trap, wherein at least one high molecular weight analyte molecule is provided within the matrix-containing particle, and MALDI on the high molecular weight particle while within the ion trap. A laser power used for ionization is sufficient to completely vaporize the particle and form at least one high molecular weight analyte ion, but is low enough to avoid fragmenting the high molecular weight analyte ion. The high molecular weight analyte ion is extracted out from the ion trap, and is then analyzed using a detector. The detector is preferably a pyrolyzing and ionizing detector.

Reilly, Peter T. A. (Knoxville, TN); Harris, William A. (Naperville, IL)

2010-03-02T23:59:59.000Z

274

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network (OSTI)

1-2% of the oil mass, however the calcium ion peak at m/z 40and elemental carbon (EC) peaks. The HDDV oil mass spectraoil mass spectra were characterized by an intense Ca + ion peak and

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

275

TVDG Ion Species  

NLE Websites -- All DOE Office Websites (Extended Search)

Most Commonly Used Ions Most Commonly Used Ions Many other ions can be produced if required. Due to the number of available ions we have to know, in advance, what ions and LETs you plan to use. Please use the Time Request fill-in form to let us know which ions you will be using. In addition to the maximum energies, ranges and corresponding LETs listed below, lower energies are available for each ion. Charts for range and LET values as a function of energy can be seen by clicking on the links in the LET columns. Flux can be in the range of 1 particle/cm2/sec to greater than 1 · 106 particles/cm2/sec. In Silicon High LET Summary Low LET Summary In GaAs High LET Summary Low LET Summary How To Use The Charts Below Mass Max Energy Surface LET Range Surface LET Range Z Symbol AMU MeV MeV

276

Trapping and dark current in plasma-based accelerators  

SciTech Connect

The trapping of thermal electrons in a nonlinear plasma wave of arbitrary phase velocity is investigated. The threshold plasma wave amplitude for trapping plasma electrons is calculated, thereby determining the fraction trapped and the expected dark current in a plasma-based accelerator. It is shown that the presence of a laser field (e.g., trapping in the self-modulated regime of the laser wakefield accelerator) increases the trapping threshold. Implications for experimental and numerical laser-plasma studies are discussed.

Schroder, C.B.; Esarey, E.; Shadwick, B.A.; Leemans, W.P.

2004-06-01T23:59:59.000Z

277

A Study of Single Pass Ion Effects at the ALS  

SciTech Connect

We report the results of experiments on a 'fast beam-ion instability' at the Advanced Light Source (ALS). This ion instability, which can arise even when the ions are not trapped over multiple beam passages, will likely be important for many future accelerators. In our experiments, we filled the ALS storage ring with helium gas, raising the pressure approximately two orders of magnitude above the nominal pressure. With gaps in the bunch train large enough to avoid conventional (multi-turn) ion trapping, we observed a factor of 2-3 increase in the vertical beam size along with coherent beam oscillations which increased along the bunch train. Ion trapping has long been recognized as a potential limitation in electron storage rings. The ions, generated by beam-gas collisions, become trapped in the negative potential of the beam and accumulate over multiple beam passages. The trapped ions are then observed to cause a number of deleterious effects such as an increasing beam phase space, a broadening and shifting of the beam transverse oscillation frequencies (tunes), collective beam instabilities, and beam lifetime reductions. All of these effects are of concern for the next generation of accelerators, such as the B-factories or damping rings for future linear colliders, which will store high beam currents with closely spaced bunches and ultra-low beam emittances. One of the standard solutions used to prevent ion trapping is to include a gap in the bunch train which is long compared to the bunch spacing. In this case, the ions are first strongly-focused by the passing electron bunches and then over-focused in the gap. With a sufficiently large gap, the ions can be driven to large amplitudes where they form a diffuse halo and do not affect the beam. In this paper, we describe experiments that study a new regime of transient ion instabilities predicted to arise in future electron storage rings, and linacs with bunch trains. These future rings and linacs, which will be operated with higher beam currents, small transverse beam emittances, and long bunch trains, will use ion clearing gaps to prevent conventional ion trapping. But, while the ion clearing gap may suppress the conventional ion instabilities, it will not suppress a transient beam-ion instability where ions generated and trapped during the passage of a single train lead to a fast instability. While both conventional and transient ion instabilities have the same origin, namely ions produced by the beam, they have different manifestations and, more importantly, the new transient instability can arise even after the conventional ion instability is cured. This new instability is called the 'Fast Beam-Ion Instability' (FBII). In many future rings, the FBII is predicted to have very fast growth rates, much faster than the damping rates of existing and proposed transverse feedback systems, and thus is a potential limitation. To study the FBII, we performed experiments at the ALS, a 1.5 GeV electron storage ring. At the nominal ALS pressure of about 0.24 nTorr, the FBII is not evident. To study the instability, we intentionally added helium gas to the storage-ring vacuum system until the residual gas pressure was increased about 80 nTorr. This brought the predicted growth rate of the instability at least an order of magnitude above the growth rate of conventional multibunch instabilities driven by the RF cavities and above the damping rate of the transverse feedback system (TFB) in the ALS and, thereby, established conditions very similar to those in a future storage ring. We then filled the ring with a relatively short train of bunches, suppressing conventional ion instabilities. In the following, we will first briefly describe This paper describes the experiment and results in more detail.

Byrd, J.M.; Thomson, J.; /LBL, Berkeley; Chao, A.W.; Heifets, S.; Minty, M.G.; Seeman, J.T.; Stupakov, G.V.; Zimmermann, F.; /SLAC; Raubenheimer, T.O.; /CERN

2011-09-13T23:59:59.000Z

278

Nanofluidic Concentration Device for Biomolecules Utilizing Ion Concentration Polarization: Theory, Fabrication, and Applications  

E-Print Network (OSTI)

Recently, a new type of electrokinetic concentration devices has been developed in a microfluidic chip format, which allows efficient trapping and concentration of biomolecules by utilizing ion concentration polarization ...

Kim, Sung Jae

279

Energy Savings Through Steam Trap Management  

E-Print Network (OSTI)

Sustainability and energy management are broad topics which have become a common focus in industry. Recognizing the need for greater cost reduction and competitive advantage through sustainability, industry is putting forth resources to improve energy management controls. When the topic of energy management relates to steam trap management however, the focus becomes less clear and action less notable. The seemingly “low hanging” fruit of steam traps are not often tied to significant and sustainable energy management projects. Typically this holds true because of the failure of industry to put a value on the cost of steam and because of the lack of energy tracking from failed steam traps as part of best practice. The use of technology can help industry transform how steam systems are managed and sustainability in steam systems is achieved.

Gibbs, C.

2008-01-01T23:59:59.000Z

280

Heavy Ions - Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ions Heavy Ions Heavy ions used at the BASE Facility are accelerated in the form of "cocktails," named because of the fact that several heavy ions with the same mass-to-charge ratio are sent into the Cyclotron, which accelerates the ions while acting as a precision mass separator. The Control Room Operator then uses Cyclotron frequency to select only the desired ion, a process that takes about 2 minutes. We provide four standard cocktails: 4.5, 10, 16, and 30 MeV/nucleon. Depending on the cocktail, LETs from 1 to 100 MeV/(mg/cm^2) and flux levels of up to 1E7 ions/cm2-sec are available. Parts are tested in our vacuum chamber, and can be remotely positioned horizontally, vertically, or rotationally (y and z axes) with the motion table. An alignment laser is available to ensure the part is in the center of the beam. Mounting hardware is readily available. 12xBNC (F-F), 2x25-pin D (F-M or M-F), 4x40-pin flat ribbon (M-M), 4x50-pin flat ribbon (M-M), 12xSMA (F-F), and 2xEthernet vacuum feedthroughs are mounted upon request. (The 4x40-pin and 4x50-pin flat ribbon connectors are wired straight across, so you will need a F-F adapter to correct the pin numbers to normal.) Holes are provided through the cave shielding blocks for connecting additional test equipment, with a distance of approximately 10 feet from vacuum feedthrough to the top of the shielding block.

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Negative mass  

E-Print Network (OSTI)

Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analyzed. Other surprising effects include the bizarre system of negative mass chasing positive pass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given.

Richard T Hammond

2013-08-06T23:59:59.000Z

282

Thermal electric vapor trap arrangement and method  

DOE Patents (OSTI)

A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself.

Alger, Terry (Tracy, CA)

1988-01-01T23:59:59.000Z

283

Marginally outer trapped surfaces in higher dimensions  

E-Print Network (OSTI)

We review the basic setup of Kaluza-Klein theory, namely a 5-dimensional vacuum with a cyclic isometry, which corresponds to Einstein-Maxwell-dilaton theory in 4-dimensional spacetime. We first recall the behaviour of Killing horizons and its generators under bundle lift and projection. We then show that the property of compact surfaces of being (stably) marginally trapped is preserved under lift and projection provided the appropriate ("Pauli-") conformal scaling is used for the spacetime metric. We also discuss and compare recently proven area inequalities for stable axially symmetric 2-dimensional and 3-dimensional marginally outer trapped surfaces.

Tim-Torben Paetz; Walter Simon

2013-02-13T23:59:59.000Z

284

Parametric Resonance of Optically Trapped Aerosols  

E-Print Network (OSTI)

The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a Lorentzian shape typical of over-damped systems (beads in liquid solvents), to a damped harmonic oscillator spectrum showing a resonance peak. In this later under-damped regime, we excite parametric resonance by periodically modulating the trapping power at twice the resonant frequency. The power spectra of position fluctuations are in excellent agreement with the obtained analytical solutions of a parametrically modulated Langevin equation.

R. Di Leonardo; G. Ruocco; J. Leach; M. J. Padgett; A. J. Wright; J. M. Girkin; D. R. Burnham; D. McGloin

2007-02-23T23:59:59.000Z

285

Landau damping of ion acoustic wave in Lorentzian multi-ion plasmas  

SciTech Connect

The Landau damping rates of ion acoustic wave are studied by using Vlasov-Poisson model for unmagnetized Lorentzian or kappa distributed plasma containing electrons, positively and negatively charged ions. It is found that the damping rate of ion acoustic wave is increased with the decrease of kappa (i.e., the spectral index of Lorentzian distribution) value. The damping rates of the electrostatic wave in multi-ion component plasmas are discussed in detail which depends on electron to ion temperature ratio and ions masses and density ratios. The numerical results are also shown by choosing some typical experimental parameters of multi-ion plasmas.

Arshad, Kashif [National Center for Plasma Physics, Quaid-i-Azam University, Shadra Valley Road, Islamabad 44000 (Pakistan); Mahmood, S. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); National Center for Plasma Physics, Quaid-i-Azam University, Shadra Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2011-09-15T23:59:59.000Z

286

Ion acoustic shock waves in degenerate plasmas  

SciTech Connect

Korteweg de Vries Burgers equation for negative ion degenerate dissipative plasma has been derived using reductive perturbation technique. The quantum hydrodynamic model is used to study the quantum ion acoustic shock waves. The effects of different parameters on quantum ion acoustic shock waves are studied. It is found that quantum parameter, electrons Fermi temperature, temperature of positive and negative ions, mass ratio of positive to negative ions, viscosity, and density ratio have significant impact on the shock wave structure in negative ion degenerate plasma.

Akhtar, N. [Theoretical Plasma Physics Division, PINSTECH, Nilore, Islamabad 44000 Pakistan (Pakistan); Hussain, S. [Theoretical Plasma Physics Division, PINSTECH, Nilore, Islamabad 44000 Pakistan (Pakistan); Department of Physics and Applied Mathematics, PIEAS, Nilore, Islamabad 44000 Pakistan (Pakistan)

2011-07-15T23:59:59.000Z

287

The Engineered Approach to Energy and Maintenance Effective Steam Trapping  

E-Print Network (OSTI)

The engineered approach to steam trap sizing, selection and application has proven effective in significantly reducing a plant's fuel consumption, maintenance and trap replacement costs while improving thermal efficiency and overall steam system performance. New field test procedures for measuring condensate load and steam loss have proven valuable in sizing traps and to determine which trap is the most energy efficient. The combination of using the engineered approach to steam trapping, field tests to verify trap performance and good maintenance practices has contributed to a major reduction in energy consumption of 10-50% in many industrial plants.

Krueger, R. G.; Wilt, G. W.

1980-01-01T23:59:59.000Z

288

Marginally trapped surfaces in spaces of oriented geodesics  

E-Print Network (OSTI)

We investigate the geometric properties of marginally trapped surfaces (surfaces which have null mean curvature vector) in the spaces of oriented geodesics of Euclidean 3-space and hyperbolic 3-space, endowed with their canonical neutral Kaehler structures. We prove that every rank one surface in these four manifolds is marginally trapped. In the Euclidean case we show that Lagrangian rotationally symmetric sections are marginally trapped and construct an explicit family of marginally trapped Lagrangian tori. In the hyperbolic case we explore the relationship between marginally trapped and Weingarten surfaces, and construct examples of marginally trapped surfaces with various properties.

Brendan Guilfoyle; Nikos Georgiou

2013-05-28T23:59:59.000Z

289

Method and apparatus for ion cyclotron spectrometry  

SciTech Connect

An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber that includes at least a first section that induces a first magnetron effect that increases a cyclotron frequency of an ion and at least a second section that induces a second magnetron effect that decreases the cyclotron frequency of an ion. The cyclotron frequency changes induced by the first and second magnetron effects substantially cancel one another so that an ion traversing the at least first and second sections will experience no net change in cyclotron frequency.

Dahl, David A. (Idaho Falls, ID); Scott, Jill R. (Idaho Falls, ID); McJunkin, Timothy R. (Idaho Falls, ID)

2010-08-17T23:59:59.000Z

290

EXTRACTION OF HIGHLY CHARGED AU IONS FROM A MULTIAMPHERE ELECTRON BEAM EBIS AT BNL.  

DOE Green Energy (OSTI)

Excellent progress has been made in the operation of the BNL Electron Beam Ion Source (EBIS), which is a prototype for an EBIS that could meet requirements for a RHIC preinjector. We have achieved very stable operation of the electron beam at 10 A through the EBIS trap. Ion injection of low charge gold ions from a LEVA [1] ion source and subsequent extraction of these ions with most probable charge state AU{sup 34+} has been demonstrated with electron beams up to 8A. The total ion charge for gold measured on current transformer at the EBIS exit was 55nC after a 30ms confinement period. This corresponds to {approx}85% of the theoretical ion trap capacity and exceeds our goal of 50% neutralization. The collected ion charge is proportional to the electron current and the gold charge state scales with the electron current density. Details of the EBIS configuration, total charge measurements, and TOF spectra are given.

BEEBE,E.N.; ALESSI,J.G.; GOULD,O.; GRAHAM,D.; KPONOU,A.; PIKIN,A.; PRELEC,K.; RITTER,J.

2001-09-02T23:59:59.000Z

291

The Spindown of Bottom-Trapped Plumes  

Science Conference Proceedings (OSTI)

This note considers the decay of a bottom-trapped freshwater plume after the causative freshwater inflow has ceased. It is shown that shortly after the low-density inflow stops, the barotropic pressure field that it created radiates away and the ...

Ricardo P. Matano; Elbio D. Palma

2010-07-01T23:59:59.000Z

292

Mass Measurements  

Science Conference Proceedings (OSTI)

... NIST maintains the national standard for mass in the form of the prototype kilogram (K20) and provides services to support the parts of the national ...

2013-06-28T23:59:59.000Z

293

fehlende Masse  

NLE Websites -- All DOE Office Websites (Extended Search)

beim radioaktiven Zerfall mit der fehlenden Masse?" Zur Erinnerung: wenn Uran in Thorium und ein alpha Teilchen zerfllt, dann gehen 0.0046 u (Masseneinheiten) der...

294

Quantum information processing and metrology with trapped ...  

Science Conference Proceedings (OSTI)

... With the use of focused laser beams, this en- ables selective qubit addressing ... out the motion of the ions (putting all modes in the ground state) with ...

2011-02-25T23:59:59.000Z

295

High voltage gas insulated transmission line with continuous particle trapping  

DOE Patents (OSTI)

This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)

1983-01-01T23:59:59.000Z

296

Ion dynamics at supercritical quasi-parallel shocks: Hybrid simulations  

Science Conference Proceedings (OSTI)

By separating the incident ions into directly transmitted, downstream thermalized, and diffuse ions, we perform one-dimensional (1D) hybrid simulations to investigate ion dynamics at a supercritical quasi-parallel shock. In the simulations, the angle between the upstream magnetic field and shock nominal direction is {theta}{sub Bn}=30 Degree-Sign , and the Alfven Mach number is M{sub A}{approx}5.5. The shock exhibits a periodic reformation process. The ion reflection occurs at the beginning of the reformation cycle. Part of the reflected ions is trapped between the old and new shock fronts for an extended time period. These particles eventually form superthermal diffuse ions after they escape to the upstream of the new shock front at the end of the reformation cycle. The other reflected ions may return to the shock immediately or be trapped between the old and new shock fronts for a short time period. When the amplitude of the new shock front exceeds that of the old shock front and the reformation cycle is finished, these ions become thermalized ions in the downstream. No noticeable heating can be found in the directly transmitted ions. The relevance of our simulations to the satellite observations is also discussed in the paper.

Su Yanqing; Lu Quanming; Gao Xinliang; Huang Can; Wang Shui [CAS Key Laboratory of Basic Plasma Physics, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 (China)

2012-09-15T23:59:59.000Z

297

HITRAP: A facility at GSI for highly charged ions  

E-Print Network (OSTI)

An overview and status report of the new trapping facility for highly charged ions at the Gesellschaft fuer Schwerionenforschung is presented. The construction of this facility started in 2005 and is expected to be completed in 2008. Once operational, highly charged ions will be loaded from the experimental storage ring ESR into the HITRAP facility, where they are decelerated and cooled. The kinetic energy of the initially fast ions is reduced by more than fourteen orders of magnitude and their thermal energy is cooled to cryogenic temperatures. The cold ions are then delivered to a broad range of atomic physics experiments.

H. -J. Kluge; T. Beier; K. Blaum; L. Dahl; S. Eliseev; F. Herfurth; B. Hofmann; O. Kester; S. Koszudowski; C. Kozhuharov; G. Maero; W. Noertershaeuser; J. Pfister; W. Quint; U. Ratzinger; A. Schempp; R. Schuch; T. Stoehlker; R. C. Thompson; M. Vogel; G. Vorobjev; D. F. A. Winters; G. Werth

2007-10-30T23:59:59.000Z

298

Silane discharge ion chemistry  

SciTech Connect

Silane dc, rf, and dc proximity discharges have been studied using mass spectroscopic measurements of the positive ions as a detailed diagnostic for the type of discharge used to produce hydrogenated amorphous silicon solar photovoltaic cells. The properties and quality of these films depends in a very complex way upon the interactions of the many reactive neutral and ion species in the discharge. Qualitative models of the ion chemical processes in these discharges have been developed from experimental measurements. Knowledge of the ion-molecule and electron-molecule collision cross sections is important to any attempt at understanding silane discharge chemistry. Consequently, the electron impact ionization cross sections for silane and disilane have been measured and for comparison purposes also for methane and ethane. In addition, the rate coefficients for charge exchange reactions of He , Ne , and Ar with silane, disilane, methane, and ethane have been measured as these are important to understanding discharges in inert gas-silane mixtures. A detailed quantitative model of the cathode sheath region of a silane dc discharge has been developed by extending the best recent calculation of the electron motion in the sheath to a self-consistent form which includes the ion motion. This model is used with comparison of silane dc discharge data to diagnose the ion chemistry occurring in the sheath region of silane dc discharge. The understanding of the discharge ion chemical processes that have been gained in this study represent an important step toward understanding the chemical and physical processes leading to film growth.

Chatham, R.H. III

1984-01-01T23:59:59.000Z

299

MASS SEPARATORS  

DOE Patents (OSTI)

An improvement in the mounting arrangement for the ion source within the vacuum tank of a calutron is presented. The entire source is supported by the vacuum envelope through the medium of a bracket secured to a removable face plate. The bracket forms a supporting platform that is generally transverse to the magnetic field. The ion generator is mounted on a pedestal-type insulator supported on the bracket, and the hot leads are brought into the vacuum envelope through a tubular elbow connected to the vacuum envelope, having the axis of its outer opening aligned with the magnetic field at which point a bushing-type insulator is employed. With this arrangement thc ion source is maintained at a positive potential with respect to the vacuum tank and the problem of electron bombardment of the insulator is considerably reduced.

Oppenheimer, F.; Bell, J.W.

1959-02-17T23:59:59.000Z

300

Use of Bullet Traps and Steel Targets  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

USE OF BULLET TRAPS AND USE OF BULLET TRAPS AND STEEL TARGETS U.S. DEPARTMENT OF ENERGY Office of Health, Safety and Security AVAILABLE ONLINE AT: INITIATED BY: http://www.hss.energy.gov Office of Health, Safety and Security Notices This document is intended for the exclusive use of elements of the Department of Energy (DOE), to include the National Nuclear Security Administration, their contractors, and other government agencies/individuals authorized to use DOE facilities. DOE disclaims any and all liability for personal injury or property damage due to use of this document in any context by any organization, group, or individual, other than during official government activities. Local DOE management is responsible for the proper execution of firearms-related programs for

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Noise-enhanced trapping in chaotic scattering  

E-Print Network (OSTI)

We show that noise enhances the trapping of trajectories in scattering systems. In fully chaotic systems, the decay rate can decrease with increasing noise due to a generic mismatch between the noiseless escape rate and the value predicted by the Liouville measure of the exit set. In Hamiltonian systems with mixed phase space we show that noise leads to a slower algebraic decay due to trajectories performing a random walk inside Kolmogorov-Arnold-Moser islands. We argue that these noise-enhanced trapping mechanisms exist in most scattering systems and are likely to be dominant for small noise intensities, which is confirmed through a detailed investigation in the Henon map. Our results can be tested in fluid experiments, affect the fractal Weyl's law of quantum systems, and modify the estimations of chemical reaction rates based on phase-space transition state theory.

Altmann, Eduardo G; 10.1103/PhysRevLett.105.244102

2010-01-01T23:59:59.000Z

302

Time of flight mass spectrometer  

DOE Patents (OSTI)

A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

Ulbricht, Jr., William H. (Arvada, CO)

1984-01-01T23:59:59.000Z

303

Multiplexed Ion Mobility Spectrometry-Orthogonal Time-of ...  

Multiplexed Ion Mobility Spectrometry-Orthogonal Time-of-Flight Mass Spectrometry Mikhail E. Belov, ... in the multiplexed IMS-TOF MS experiments ...

304

Nanopost Arrays Anchor Molecules, Improve Ion Yields for Laser ...  

ORNL 2011-G00228/jcn UT-B ID 200902284 09.2011 Nanopost Arrays Anchor Molecules, Improve Ion Yields for Laser Mass Spectrometry Technology Summary

305

What To Do With Cold Traps and Why  

E-Print Network (OSTI)

Increased emphasis on energy management has helped sites reduce system cost through the diagnosis and repair of “Leaking” or “Blowing” steam traps (“Leakage Failures”). Timely maintenance response is a significant action to lower energy use and GHG emissions generated by steam production. But, what action should be taken with Cold Traps? In every steam trap survey to determine the steam trap population’s current state of health, there are usually a significant amount of steam traps determined to be “Cold” or “Low Temp” (“Drainage Failures” or “Cold Traps”). It seems that site personnel commonly assign a lower response priority to these Drainage Failures traps, and sometimes actually implement a practice to intentionally convert Leaking traps into Cold Traps by closing the inlet stop valve to immediately stop energy leakage. Subsequently, they may label those traps as “Valved- Out” or “Out of Service,” but those trap stations were originally designed as needed to drain retained condensate from the system. So, the correct designation for such a trap station is “Cold,” regardless of the current intention. If the trap station does not drain condensate and is not hot, it is “Cold.” It can be astounding that many sites are not convinced of what actions or priority to take to repair Cold Traps, even while intrinsically understanding that there is something wrong with having Cold Traps that cannot drain condensate from a steam system. It often is simply because sites may not be fully aware of the potential dangers of uncorrected Cold Traps or the significant safety, reliability, and energy benefits of addressing them. Although safety is always the main priority, it cannot be overstated that there are huge reliability and energy benefits to prioritized repair of Cold Traps. Unfortunately, proactive response to repair Cold Traps in a steam system is not always achieved, often because the real benefits of such a response are not understood. Therefore, further review of “WHAT TO DO ABOUT COLD TRAPS…AND WHY?” is warranted for safe, reliable, and energy-efficient management of the condensate discharge locations (CDLs). Several tables are provided to help sites valuate the cost impact of Cold Traps in their steam systems by using readily available historical data.

Risko, J. R.; Walter, J. P.

2012-01-01T23:59:59.000Z

306

Laser Ion Source Development at HRIBF  

Science Conference Proceedings (OSTI)

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:Sapphire lasers for nuclear physics and astrophysics research at HRIBF. Three Ti:Sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Yuan [ORNL; Beene, James R [ORNL; Havener, Charles C [ORNL; Howe, Jane Y [ORNL; Kiggans, Jim [ORNL; Vane, C Randy [ORNL; Mattolat, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Gottwald, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2012-01-01T23:59:59.000Z

307

Ion Rings for Magnetic Fusion  

Science Conference Proceedings (OSTI)

This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation of a reactor-scale FRC, and the FIREX program was intended to test the ideas behind this approach. We will describe in this report the technological development path and advances in physics understanding that allowed FIREX to reach a regime in which ion rings were reproducibly created with up to about half the current necessary to produce field reversal. Unfortunately, the experiments were limited to this level by a fundamental, unanticipated aspect of the physics of strong ion rings in plasma. The FIREX ring is a strongly anisotropic, current-carrying population of ions moving faster than the Alfven speed in the background plasma. The rapidly changing ring current excites very large-amplitude Alfven waves in the plasma, and these waves strongly affect the ring, causing rapid energy loss in a way that is not compatible with the success of the ring trapping scenario around which FIREX was designed. The result was that FIREX rings were always very short-lived. We will discuss the implication of these results for possible future use of large-orbit ions in FRCs. In short, it appears that a certain range of the parameters characterizing the ring Alfven mach number and distribution function must be avoided to allow the existence of a long-lived energetic ion component in an FRC. This report will explain why FIREX experimental results cannot be directly scaled to quantitatively predict this range for a particular FRC configuration. This will require accurate, three-dimensional simulations. FIREX results do constitute a very good dataset for validating such a code, and simulations already carried out during this program provide a guide to the important physics involved.

Greenly, John, B.

2005-07-31T23:59:59.000Z

308

Antihydrogen and mirror-trapped antiproton discrimination: Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap  

E-Print Network (OSTI)

Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antiproton and antihydrogen trajectories in this magnetic geometry, and reconstruct the antihydrogen energy distribution from the measured annihilation time history.

C. Amole; G. B. Andresen; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; A. Deller; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; A. J. Humphries; R. Hydomako; L. Kurchaninov; S. Jonsell; N. Madsen; S. Menary; P. Nolan; K. Olchanski; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele

2012-01-18T23:59:59.000Z

309

Highly charged ion based time of flight emission microscope  

DOE Patents (OSTI)

A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

Barnes, Alan V. (Livermore, CA); Schenkel, Thomas (San Francisco, CA); Hamza, Alex V. (Livermore, CA); Schneider, Dieter H. (Livermore, CA); Doyle, Barney (Albuquerque, NM)

2001-01-01T23:59:59.000Z

310

Steam Traps-The Oft Forgotten Energy Conservation Treasure  

E-Print Network (OSTI)

In these days of high technology, the steam trap is often treated as a commodity item, forgotten by many and respected by a relative few. Yet, in many facilities, widespread undetected failure of steam traps has wasted 5-15% of a plant's total steam generation. Stopping this waste represents a major energy conservation treasure characterized by low investment and a fast payback. The proper application of steam trap technology requires the experience and judgment of a dedicated champion at each location. This paper will present an overview of a working steam trap program starting with the initial survey and loss estimates. Trap characteristics and performance by generic type will be discussed with practical examples utilized to illustrate the myths in steam trap sizing and the consequences of over-sizing. Standardization of trap inventory, training and follow-up are the other key program elements addressed.

Pychewicz, F. S.

1985-05-01T23:59:59.000Z

311

ION SWITCH  

DOE Patents (OSTI)

An ion switch capable of transferring large magnitudes of power is described. An ion switch constructed in accordance with the invention includes a pair of spaced control electrodes disposed in a highly evacuated region for connection in a conventional circuit to control the passing of power therethrough. A controllable ionic conduction path is provided directiy between the control electrodes by a source unit to close the ion switch. Conventional power supply means are provided to trigger the source unit and control the magnitude, durations and pulse repetition rate of the aforementioned ionic conduction path.

Cook, B.

1959-02-10T23:59:59.000Z

312

ION SOURCE  

DOE Patents (OSTI)

An ion source is described and comprises an arc discharge parallel to the direction of and inside of a magnetic field. an accelerating electrode surrounding substantially all of the discharge except for ion exit apertures, and means for establishing an electric field between that electrode and the arc discharge. the electric field being oriented at an acute angle to the magnetic field. Ions are drawn through the exit apertures in the accelrating electrcde in a direction substantially divergent to the direction of the magnetic field and so will travel in a spiral orbit along the magnetic field such that the ions will not strike the source at any point in their orbit within the magnetic field.

Blue, C.W.; Luce, J.S.

1960-07-19T23:59:59.000Z

313

Low-power, miniature {sup 171}Yb ion clock using an ultra-small vacuum package  

SciTech Connect

We report a demonstration of a very small microwave atomic clock using the 12.6 GHz hyperfine transition of the trapped {sup 171}Yb ions inside a miniature, completely sealed-off 3 cm{sup 3} ion-trap vacuum package. In the ion clock system, all of the components are highly miniaturized with low power consumption except the 369 nm optical pumping laser still under development for miniaturization. The entire clock, including the control electronics, consumes <300 mW. The fractional frequency instability of the miniature Yb{sup +} clock reaches the 10{sup -14} range after a few days of integration.

Jau, Y.-Y.; Schwindt, P. D. D. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Partner, H. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Quantum Information and Control (CQuIC), Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Prestage, J. D.; Kellogg, J. R.; Yu, N. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2012-12-17T23:59:59.000Z

314

Void trapping of hydrogen in sintered iron  

DOE Green Energy (OSTI)

The effect of void trapping of hydrogen in iron was studied using the gas-phase permeation technique. Iron membranes of controlled void density, varying from 92% to 98% were prepared by press and sintering of electrolytic iron powder. The presence of internal voids showed no effect on the steady state flux of hydrogen through the membrane. The effective diffusivity, obtained by the time lag method, increased with the increase of input hydrogen partial pressure. This disagreement with the prediction of the theory in literature was explained by the existence of hydrogen in both the diatomic gaseous form and as adsorbed hydrogen. This explanation was further confirmed by examining the dependence of trapped hydrogen concentration with pressure. The linear dependence of trapped hydrogen concentration in voids with external hydrogen partial pressure for samples of 96%, 94% and 92% dense were given respectively by C/sub g/ = (1.5 +- 0.2) x 10/sup 15/ P + (3.2 +- 0.5) x 10/sup 14/ atoms of H/c.c. C/sub g/ = (2.1 +- 0.6) x 10/sup 15/ P + (1.7 +- 0.5) x 10/sup 15/ atoms of H/c.c. C/sub g/ = (4.5 +- 0.3) x 10/sup 15/ P + (6.5 +- 0.2) x 10/sup 15/ atoms of H/c.c. The discrepancy between the reported values and the values predicted by theory was explained by the poisoning of some of the voids by surface oxides.

Wong, K.C.

1976-09-01T23:59:59.000Z

315

Gas turbine engines with particle traps  

DOE Patents (OSTI)

A gas turbine engine (10) incorporates a particle trap (46) that forms an entrapment region (73) in a plenum (24) which extends from within the combustor (18) to the inlet (32) of a radial-inflow turbine (52, 54). The engine (10) is thereby adapted to entrap particles that originate downstream from the compressor (14) and are otherwise propelled by combustion gas (22) into the turbine (52, 54). Carbonaceous particles that are dislodged from the inner wall (50) of the combustor (18) are incinerated within the entrapment region (73) during operation of the engine (10).

Boyd, Gary L. (Tempe, AZ); Sumner, D. Warren (Phoenix, AZ); Sheoran, Yogendra (Scottsdale, AZ); Judd, Z. Daniel (Phoenix, AZ)

1992-01-01T23:59:59.000Z

316

Impurity beam-trapping instability in tokamaks  

SciTech Connect

The sensitivity of neutron energy production to the impurity trapping of injected neutral beams is considered. This process is affected by inherent low-Z contamination of the tritium pre-heat plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process to these variables, and to the variation of wall material are compared. One finds that successful use of a low-Z, low-sputtering material can appreciably lengthen the useful pulse length. (auth)

Hogan, J.T.; Howe, H.C.

1976-01-01T23:59:59.000Z

317

Trapped Quintessential Inflation from Flux Compactifications  

E-Print Network (OSTI)

Quintessential inflation is studied using a string modulus as the inflaton - quintessence field. It is assumed that the modulus crosses an enhanced symmetry point (ESP) in field space. Particle production at the ESP temporarily traps the modulus resulting in a period of inflation. After reheating, the modulus freezes due to cosmological friction at a large value, such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions. The modulus remains frozen until the present, when it can become quintessence.

Konstantinos Dimopoulos

2007-02-01T23:59:59.000Z

318

New nano trap protects environment | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

New nano trap protects environment New nano trap protects environment By Tona Kunz * October 31, 2012 Tweet EmailPrint This story was originally published in volume 10, number 5 of Innovation magazine. A new type of nanoscale molecular trap makes it possible for industry to store large amounts of hydrogen in small fuel cells or capture, compact and remove volatile radioactive gas from spent nuclear fuel in an affordable, easily commercialized way. The ability to adjust the size of the trap openings to select for specific molecules or to alter how molecules are released at industrially accessible pressures makes the trap uniquely versatile. The trap is constructed of commercially available material and made possible through collaborative work at Argonne and Sandia national laboratories. "This introduces a new class of materials to nuclear waste remediation,"

319

High-energy accelerator for beams of heavy ions  

DOE Patents (OSTI)

An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

Martin, Ronald L. (La Grange, IL); Arnold, Richard C. (Chicago, IL)

1978-01-01T23:59:59.000Z

320

Energy trapping from Hagedorn densities of states  

E-Print Network (OSTI)

In this note, we construct simple stochastic toy models for holographic gauge theories in which distributions of energy on a collection of sites evolve by a master equation with some specified transition rates. We build in only energy conservation, locality, and the standard thermodynamic requirement that all states with a given energy are equally likely in equilibrium. In these models, we investigate the qualitative behavior of the dynamics of the energy distributions for different choices of the density of states for the individual sites. For typical field theory densities of states (\\log(\\rho(E)) ~ E^{\\alphaenergy spread out relatively quickly. For large N gauge theories with gravitational duals, the density of states for a finite volume of field theory degrees of freedom typically includes a Hagedorn regime (\\log(\\rho(E)) ~ E). We find that this gives rise to a trapping of energy in subsets of degrees of freedom for parametrically long time scales before the energy leaks away. We speculate that this Hagedorn trapping may be part of a holographic explanation for long-lived gravitational bound states (black holes) in gravitational theories.

Connor Behan; Klaus Larjo; Nima Lashkari; Brian Swingle; Mark Van Raamsdonk

2013-04-26T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Ion optical design of a collinear laser-negative ion beam apparatus  

Science Conference Proceedings (OSTI)

An apparatus for photodetachment studies on atomic and molecular negative ions of medium up to heavy mass (M {approx_equal} 500) has been designed and constructed. Laser and ion beams are merged in the apparatus in a collinear geometry and atoms, neutral molecules and negative ions are detected in the forward direction. The ion optical design and the components used to optimize the mass resolution and the transmission through the extended field-free interaction region are described. A 90 deg. sector field magnet with 50 cm bending radius in combination with two slits is used for mass dispersion providing a resolution of M/{Delta}M congruent with 800 for molecular ions and M/{Delta}M congruent with 400 for atomic ions. The difference in mass resolution for atomic and molecular ions is attributed to different energy distributions of the sputtered ions. With 1 mm slits, transmission from the source through the interaction region to the final ion detector was determined to be about 0.14%.

Diehl, C.; Wendt, K. [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz, D-55099 Mainz (Germany); Lindahl, A. O.; Andersson, P.; Hanstorp, D. [Department of Physics, University of Gothenburg, SE-412 96 Goeteborg (Sweden)

2011-05-15T23:59:59.000Z

322

Gas insulated transmission line having tapered particle trapping ring  

DOE Patents (OSTI)

A gas-insulated transmission line includes an outer sheath, an inner conductor, insulating supports and an insulating gas. A particle-trapping ring is secured to each insulating support, and it is comprised of a central portion and two tapered end portions. The ends of the particle trapping ring have a smaller diameter than the central portion of the ring, so as to enable the use of the particle trapping ring in a curved transmission line.

Cookson, Alan H. (Pittsburgh, PA)

1982-01-01T23:59:59.000Z

323

Destabilization of the trapped electron mode by magnetic curvature drift resonances  

SciTech Connect

Electron curvature drift resonances, ignored in earlier work on the trapped-electron modes, are found to exert a strong destabilizing influence in the lower collision frequency range of these instabilities. Effects arising from ion temperature gradients, shear, and finite ion gyroradius are included with these vector nebla-drifts in the analysis, and the resultant eigenvalue equation is solved by numerical procedures rather than the commonly used perturbation techniques. For typical tokamak parameters the maximum growth rates are found to be increased over earlier estimates by roughly a factor of 4, and requirements on magnetic shear strength for stabilization are likewise more severe and very difficult to satisfy. For inverted density profiles, this new destabilizing effect is rendered ineffective, with the result that the modes can be stabilized for achievable values of shear provided the temperature gradients are not too severe. Estimates of the particle and thermal energy transport are given for both normal and inverted profiles. (auth)

Adam, J.C.; Tang, W.M.; Rutherford, P.H.

1975-12-01T23:59:59.000Z

324

Feedback-Optimized Operations with Linear Ion Crystals  

E-Print Network (OSTI)

We report on transport operations with linear crystals of 40Ca+ ions by applying complex electric time-dependent potentials. For their control we use the information obtained from the ions' fluorescence. We demonstrate that by means of this feedback technique, we can transport a predefined number of ions and also split and unify ion crystals. The feedback control allows for a robust scheme, compensating for experimental errors as it does not rely on a precisely known electrical modeling of the electric potentials in the ion trap beforehand. Our method allows us to generate a self-learning voltage ramp for the required process. With an experimental demonstration of a transport with more than 99.8 % success probability, this technique may facilitate the operation of a future ion based quantum processor.

Eble, J F; Zahariev, P; Schmidt-Kaler, F; Singer, K

2009-01-01T23:59:59.000Z

325

Feedback-Optimized Operations with Linear Ion Crystals  

E-Print Network (OSTI)

We report on transport operations with linear crystals of 40Ca+ ions by applying complex electric time-dependent potentials. For their control we use the information obtained from the ions' fluorescence. We demonstrate that by means of this feedback technique, we can transport a predefined number of ions and also split and unify ion crystals. The feedback control allows for a robust scheme, compensating for experimental errors as it does not rely on a precisely known electrical modeling of the electric potentials in the ion trap beforehand. Our method allows us to generate a self-learning voltage ramp for the required process. With an experimental demonstration of a transport with more than 99.8 % success probability, this technique may facilitate the operation of a future ion based quantum processor.

J. F. Eble; S. Ulm; P. Zahariev; F. Schmidt-Kaler; K. Singer

2009-12-13T23:59:59.000Z

326

Trap-depth determination from residual gas collisions  

SciTech Connect

We present a method for determining the depth of an atomic or molecular trap of any type. This method relies on a measurement of the trap loss rate induced by collisions with background gas particles. Given a fixed gas composition, the loss rate uniquely determines the trap depth. Because of the ''soft'' long-range nature of the van der Waals interaction, these collisions transfer kinetic energy to trapped particles across a broad range of energy scales, from room temperature to the microkelvin energy scale. The resulting loss rate therefore exhibits a significant variation over an enormous range of trap depths, making this technique a powerful diagnostic with a large dynamic range. We present trap depth measurements of a Rb magneto-optical trap using this method and a different technique that relies on measurements of loss rates during optical excitation of colliding atoms to a repulsive molecular state. The main advantage of the method presented here is its large dynamic range and applicability to traps of any type requiring only knowledge of the background gas density and the interaction potential between the trapped and background gas particles.

Van Dongen, J.; Zhu, C.; Clement, D.; Dufour, G.; Madison, K. W. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, V6T 1Z1 (Canada); Booth, J. L. [Physics Department, British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, British Columbia, V5G 3H2 (Canada)

2011-08-15T23:59:59.000Z

327

Bon MOT: Innovative Atom Trap Catches Highly Magnetic ...  

Science Conference Proceedings (OSTI)

... of a cloud of erbium atoms trapped and cooled and a ... all the while extracting energy and cooling them ... only a single laser and can cool erbium atoms ...

2011-07-18T23:59:59.000Z

328

Possible mechanism for enhancing the trapping and cooling of antihydrogen  

SciTech Connect

We propose a usage of microwave radiation in a magnetic trap for improving the cooling and trapping of cold antihydrogen atoms which are initially produced in high magnetic moment states. Inducing transitions toward lower magnetic moments near the turning points of the atom in the trap, followed by spontaneous emission, should enhance the number of trappable atoms. We present results of simulations based on a typical experimental condition of the antihydrogen experiments at CERN. This technique should also be applicable to other trapped high magnetic moment Rydberg atoms.

Cesar, C. L.; Zagury, N. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil); Robicheaux, F. [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

2009-10-15T23:59:59.000Z

329

Onset of Fermi Degeneracy in a Trapped Atomic Gas  

Science Conference Proceedings (OSTI)

... in the total energy of the ultra- cold, trapped ... of charge e onto a cryogenic capacitor C, and ... standards are known as “calculable capacitors” and rely ...

2010-07-12T23:59:59.000Z

330

Trapping and Measuring Charged Particles in Liquids - Energy ...  

Genome sequencing especially benefits from the nanoscale approach. Description. The trap is a three-layer, three-dimensional crossing metal/insulator ...

331

How Algae Use a "Sulfate Trap" to Selectively Biomineralize Strontium...  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed How Algae Use a "Sulfate Trap" to Selectively Biomineralize Strontium OCTOBER 20, 2011 Bookmark...

332

Bait formulations and longevity of navel orangeworm egg traps tested  

E-Print Network (OSTI)

there were 1% or 3% crude almond oil received more eggshaving no letters crude almond oil or traps baited with inone standard error. crude almond oil received significantly

Kuenen, L.P.S. Bas; Bentley, Walt; Rowe, Heather; Ribeiro, Brian

2008-01-01T23:59:59.000Z

333

November 18, 2010: Antimatter Trapped and Stored | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Stored November 18, 2010 The Department's Lawrence Berkeley National Laboratory (LBNL) announces that atoms of antimatter have been trapped and stored for the first time in...

334

Bait formulations and longevity of navel orangeworm egg traps tested  

E-Print Network (OSTI)

traps tested by L.P.S. (Bas) Kuenen, Walt Bentley, Heatherfor at least 10 weeks. L.P.S. (Bas) Kuenen is Research

Kuenen, L.P.S. Bas; Bentley, Walt; Rowe, Heather; Ribeiro, Brian

2008-01-01T23:59:59.000Z

335

Josephson oscillations between exciton condensates in electrostatic traps  

SciTech Connect

Technological advances allow for tunable lateral confinement of cold dipolar excitons in coupled quantum wells. We consider theoretically the Josephson effect between exciton condensates in two traps separated by a weak link. The flow of the exciton supercurrent is driven by the dipole-energy difference between the traps. The Josephson oscillations may be observed after ensemble average of the time correlation of photons separately emitted from the two traps. The fringe visibility is controlled by the trap coupling and is robust against quantum and thermal fluctuations.

Rontani, Massimo [CNR-INFM Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/A, 41125 Modena (Italy); Sham, L. J. [Department of Physics, University of California San Diego, La Jolla, California 92093-0319 (United States)

2009-08-15T23:59:59.000Z

336

Tellurium Inclusions and Carrier Trapping Times in Detector Grade ...  

Science Conference Proceedings (OSTI)

Spatial mapping of carrier trapping times and defect densities in CZT was performed to determine the relationship between defect density and electronic decay.

337

The angular momentum of a magnetically trapped atomic condensate  

E-Print Network (OSTI)

For an atomic condensate in an axially symmetric magnetic trap, the sum of the axial components of the orbital angular momentum and the hyperfine spin is conserved. Inside an Ioffe-Pritchard trap (IPT) whose magnetic field (B-field) is not axially symmetric, the difference of the two becomes surprisingly conserved. In this paper we investigate the relationship between the values of the sum/difference angular momentums for an atomic condensate inside a magnetic trap and the associated gauge potential induced by the adiabatic approximation. Our result provides significant new insight into the vorticity of magnetically trapped atomic quantum gases.

P. Zhang; H. H. Jen; C. P. Sun; L. You

2006-11-14T23:59:59.000Z

338

Electron traps in organic light-emitting diodes  

Science Conference Proceedings (OSTI)

This work presents the effects of electron traps in organic light-emitting diodes using a model which includes charge injection

Min-Jan Tsai; Hsin-Fei Meng

2005-01-01T23:59:59.000Z

339

Fundamental and methodological investigations for the improvement of elemental analysis by inductively coupled plasma mass soectrometry  

Science Conference Proceedings (OSTI)

This dissertation describes a variety of studies meant to improve the analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA) ICP-MS. The emission behavior of individual droplets and LA generated particles in an ICP is studied using a high-speed, high frame rate digital camera. Phenomena are observed during the ablation of silicate glass that would cause elemental fractionation during analysis by ICP-MS. Preliminary work for ICP torch developments specifically tailored for the improvement of LA sample introduction are presented. An abnormal scarcity of metal-argon polyatomic ions (MAr{sup +}) is observed during ICP-MS analysis. Evidence shows that MAr{sup +} ions are dissociated by collisions with background gas in a shockwave near the tip of the skimmer cone. Method development towards the improvement of LA-ICP-MS for environmental monitoring is described. A method is developed to trap small particles in a collodion matrix and analyze each particle individually by LA-ICP-MS.

Ebert, Christopher Hysjulien [Ames Laboratory

2012-07-27T23:59:59.000Z

340

Negative Halogen Ions for Fusion Applications  

DOE Green Energy (OSTI)

Over the past quarter century, advances in hydrogen negative ion sources have extended the usable range of hydrogen isotope neutral beams to energies suitable for large magnetically confined fusion devices. Recently, drawing upon this experience, negative halogen ions have been proposed as an alternative to positive ions for heavy ion fusion drivers in inertial confinement fusion, because electron accumulation would be prevented in negative ion beams, and if desired, the beams could be photo-detached to neutrals. This paper reports the results of an experiment comparing the current density and beam emittance of Cl+ and Cl- extracted from substantially ion-ion plasmas with that of Ar+ extracted from an ordinary electron-ion plasma, all using the same source, extractor, and emittance scanner. At similar discharge conditions, the Cl- current was typically 85 – 90% of the positive chlorine current, with an e-/ Cl- ratio as low as seven without grid magnets. The Cl- was as much as 76% of the Ar+ current from a discharge with the same RF drive. The minimum normalized beam emittance and inferred ion temperatures of Cl+, Cl-, and Ar+ were all similar, so the current density and optical quality of Cl- appear as suitable for heavy ion fusion driver applications as a positive noble gas ion of similar mass. Since F, I, and Br should all behave similarly in an ion source, they should also be suitable as driver beams.

Grisham, L.R.; Kwan, J.W.; Hahto, S.K.; Hahto, S.T.; Leung, K.N.; Westenskow, G.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Ion Distribution And Electronic Stopping Power For Au ions In Silicon Carbide  

SciTech Connect

Accurate knowledge of ion distribution and electronic stopping power for heavy ions in light targets is highly desired due to the large errors in prediction by the widely used Stopping and Range of Ions in Matter (SRIM) code. In this study, Rutherford backscattering spectrometry (RBS)and secondary ion mass spectrometry (SIMS) are used as complementary techniques to determine the distribution of Au ions in SiC with energie sfrom 700 keV to 15 MeV. In addition, asingle ion technique with an improved data analysis procedure is applied to measure the electronic stopping power for Au ions in SiC with energies up to ~70 keV/nucleon. Large overestimation of the electronic stopping power is found by SRIM prediction in the low energy regime up to ~50 keV/nucleon. The stopping power data and the ion ranges are crosschecked with each other and a good agreement is achieved.

Jin, Ke; Zhang, Yanwen; Xue, Haizhou; Zhu, Zihua; Weber, William J.

2013-07-15T23:59:59.000Z

342

Maximizing Ion Current by Space Charge Neutralization using Negative Ions and Dust Particles  

DOE Green Energy (OSTI)

Ion current extracted from an ion source (ion thruster) can be increased above the Child-Langmuir limit if the ion space charge is neutralized. Similarly, the limiting kinetic energy density of the plasma flow in a Hall thruster might be exceeded if additional mechanisms of space charge neutralization are introduced. Space charge neutralization with high-mass negative ions or negatively charged dust particles seems, in principle, promising for the development of a high current or high energy density source of positive light ions. Several space charge neutralization schemes that employ heavy negatively charged particles are considered. It is shown that the proposed neutralization schemes can lead, at best, only to a moderate but nonetheless possibly important increase of the ion current in the ion thruster and the thrust density in the Hall thruster.

A. Smirnov; Y. Raitses; N.J. Fisch

2005-01-25T23:59:59.000Z

343

Dynamic multiplexed analysis method using ion mobility spectrometer  

DOE Patents (OSTI)

A method for multiplexed analysis using ion mobility spectrometer in which the effectiveness and efficiency of the multiplexed method is optimized by automatically adjusting rates of passage of analyte materials through an IMS drift tube during operation of the system. This automatic adjustment is performed by the IMS instrument itself after determining the appropriate levels of adjustment according to the method of the present invention. In one example, the adjustment of the rates of passage for these materials is determined by quantifying the total number of analyte molecules delivered to the ion trap in a preselected period of time, comparing this number to the charge capacity of the ion trap, selecting a gate opening sequence; and implementing the selected gate opening sequence to obtain a preselected rate of analytes within said IMS drift tube.

Belov, Mikhail E [Richland, WA

2010-05-18T23:59:59.000Z

344

Mass Finishing  

Science Conference Proceedings (OSTI)

Table 8 Operating conditions for mass finishing...Brass screw-machine parts Aluminum oxide or granite 6.4-19 0.25-0.75 [MathExpression] -6 Light matte or bright Light cutting (a) Brass stampings or screws (b) Limestone 3.2-13 0.13-0.50 2-6 Bright (a) Submerged tumbling is used for fragile and precision parts. (b) Screw-machine parts...

345

Plasma Mass Filters For Nuclear Waste Reprocessing  

SciTech Connect

Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

Abraham J. Fetterman and Nathaniel J. Fisch

2011-05-26T23:59:59.000Z

346

Selection, Sizing, and Testing of Stream Traps in Commercial Buildings  

E-Print Network (OSTI)

For maximum effectiveness in steam systems, steam traps should have operating characteristics which closely match the requirements of the applications for which they are used. A trap which holds back condensate until it is subcooled and some of the sensible heat has been utilized is unsuitable where the need is to get maximum output from an exchanger by discharging condensate as soon as it forms. Equally, a trap discharging condensate at steam temperature can exacerbate flash steam problems in cases where surplus heat exchange area exists and a subcooling trap might be more suitable. In all cases, undersized traps simply cannot drain condensate from the steam equipment at the required rate, while oversized traps which cost more will usually wear faster and begin leaking expensive steam. This emphasizes the need for carefully selecting trap sizes that are properly engineered for maximum system efficiency. And, of course, the ability of a trap to cope with varying loads and to discharge noncondensible gases is often important. The recommended procedure is to first select the trap type which has performance capabilities that satisfy specific application needs, and then to choose a size which handles the condensate load without any unnecessary excess capacity. The Selection Guide, Table 1, is not comprehensive but helps in many applications where no unusual operating conditions or severe corrosion problems exist. Choosing the correct trap size then implies estimating the steam consumption rate, which of course equals the condensate load. Sometimes the load has already been measured, or the rated output of the steam equipment is known or can be obtained from the original manufacturer. In other cases, an estimate must be made and a Table o f Load Formulas will help although it, too, cannot be comprehensive. After making the best possible estimate of the load, a safety factor is applied. This allows for any inaccuracies in the estimating, for increased condensation rates at start-up, and for lower than anticipated pressure differentials across the trap.

Armer, A.; Risko, J. R.

1984-01-01T23:59:59.000Z

347

Debris trap in a turbine cooling system  

SciTech Connect

In a turbine having a rotor and a plurality of stages, each stage comprising a row of buckets mounted on the rotor for rotation therewith; and wherein the buckets of at least one of the stages are cooled by steam, the improvement comprising at least one axially extending cooling steam supply conduit communicating with an at least partially annular steam supply manifold; one or more axially extending cooling steam feed tubes connected to the manifold at a location radially outwardly of the cooling steam supply conduit, the feed tubes arranged to supply cooling steam to the buckets of at least one of the plurality of stages; the manifold extending radially beyond the feed tubes to thereby create a debris trap region for collecting debris under centrifugal loading caused by rotation of the rotor.

Wilson, Ian David (Clifton Park, NY)

2002-01-01T23:59:59.000Z

348

Can aerosols be trapped in open flows?  

E-Print Network (OSTI)

The fate of aerosols in open flows is relevant in a variety of physical contexts. Previous results are consistent with the assumption that such finite-size particles always escape in open chaotic advection. Here we show that a different behavior is possible. We analyze the dynamics of aerosols both in the absence and presence of gravitational effects, and both when the dynamics of the fluid particles is hyperbolic and nonhyperbolic. Permanent trapping of aerosols much heavier than the advecting fluid is shown to occur in all these cases. This phenomenon is determined by the occurrence of multiple vortices in the flow and is predicted to happen for realistic particle-fluid density ratios.

Rafael D. Vilela; Adilson E. Motter

2007-06-10T23:59:59.000Z

349

Sympathetic Cooling of Molecular Ions in Selected Rotational and Vibrational States Produced by Threshold Photoionization  

SciTech Connect

We present a new method for the generation of rotationally and vibrationally state-selected, translationally cold molecular ions in ion traps. Our technique is based on the state-selective threshold photoionization of neutral molecules followed by sympathetic cooling of the resulting ions with laser-cooled calcium ions. Using N{sub 2}{sup +} ions as a test system, we achieve >90% selectivity in the preparation of the ground rovibrational level and state lifetimes on the order of 15 minutes limited by collisions with background-gas molecules. The technique can be employed to produce a wide range of apolar and polar molecular ions in the ground and excited rovibrational states. Our approach opens up new perspectives for cold quantum-controlled ion-molecule-collision studies, frequency-metrology experiments with state-selected molecular ions and molecular-ion qubits.

Tong Xin; Winney, Alexander H.; Willitsch, Stefan [Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel (Switzerland)

2010-10-01T23:59:59.000Z

350

HML Organic Chemical Metrology Program Areas  

Science Conference Proceedings (OSTI)

... Gas chromatography with electron capture detection; Liquid chromatography (including nano-liquid chromatography) with linear ion trap mass ...

2012-11-16T23:59:59.000Z

351

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP  

E-Print Network (OSTI)

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP R. B. AIKEN underwater light trap isdescribed. Trap records indicate that the trap iseffective in taking a wide variety. (1955) described the construction and operation of an underwater light trap. Their records indi- cate

Aiken, Ron

352

Effective Steam Trap Selection/Maintenance - Its Payback  

E-Print Network (OSTI)

In oil refineries and petrochemical plants large number of steam traps are used to discharge condensate from steam mains, tracers and process equipment. Early efforts on steam traps focused almost exclusively on their selection and sizing, and it was not until the 1973 oil embargo that a need for regular maintenance became recognized. Although relatively small pieces of equipment, traps are responsible for large quantities of steam losses, decreased equipment efficiency and high maintenance costs; e.g., a steam trap leaking 100 psig steam through a 1/8 inch orifice costs at least $2k/yr if steam is valued at $5/k lb. Typically, a steam trap survey identifies 20-60% of traps malfunctioning. Therefore, establishing an effective steam trap selection/maintenance program is not simple but can be extremely profitable. This paper will show how a successful checking/maintenance program can result in high returns by using a case study at an Exxon plant. The example also shows how a central engineering organization can interact with plant technicians/ maintenance personnel to help implement an effective steam trap maintenance program at competitive costs and high returns.

Garcia, E.

1984-01-01T23:59:59.000Z

353

Negative ion source  

DOE Patents (OSTI)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, James E. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

354

Improved negative ion source  

DOE Patents (OSTI)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, J.E.

1984-05-01T23:59:59.000Z

355

Observation of Beam ION Instability in Spear3  

SciTech Connect

Weak vertical coupled bunch instability with oscillation amplitude at {mu}m level has been observed in SPEAR3. The instability becomes stronger when there is a vacuum pressure rise by partially turning off vacuum pumps and it becomes weaker when the vertical beam emittance is increased by turning off the skew quadrupole magnets. These confirmed that the instability was driven by ions in the vacuum. The threshold of the beam ion instability when running with a single bunch train is just under 200 mA. This paper presents the comprehensive observations of the beam ion instability in SPEAR3. The effects of vacuum pressure, beam current, beam filling pattern, chromaticity, beam emittance and bunch-by-bunch feedback are investigated in great detail. In an electron accelerator, ions generated from the residual gas molecules can be trapped by the beam. Then these trapped ions interact resonantly with the beam and cause beam instability and emittance blow-up. Most existing light sources use a long single bunch train filling pattern, followed by a long gap to avoid multi-turn ion trapping. However, such a gap does not preclude ions from accumulating during one passage of the single bunch train beam, and those ions can still cause a Fast Ion Instability (FII) as predicted by Raubenheimer and Zimmermann. FII has been observed in ALS, and PLS by artificially increasing the vacuum pressure by injecting helium gas into the vacuum chamber or by turning off the ion pumps in order to observe the beam ion instability. In some existing rings, for instance B factory, the beam ion instability was observed at the beginning of the machine operation after a long period of shutdown and then it automatically disappeared when the vacuum was better. However, when the beam emittance becomes smaller, the FII can occur at nominal conditions as observed in PLS, SOLEIL and SSRF. This paper reports the observations of beam ion instabilities in SPEAR3 under different condition during a period of one year, which includes single bunch train instability (FII) and multi-bunch train instability. Note that the instability may be not the same even with the same beam due to the change of the vacuum with time. SPEAR3 has a circumference of 234 m with a harmonic number of 372. SPEAR3 runs with six bunch train filling pattern in order to suppress the possible beam ion instability. Table 1 lists the main parameters of SPEAR3. The vacuum of SPEAR3 ranges from 0.1 to 0.5 nTorr, which varies from section to section.

Teytelman, D.; /Dimtel, Redwood City; Cai, Y.; Corbett, W.J.; Raubenheimer, T.O.; Safranek, J.A.; Schmerge, J.F.; Sebek, J.J.; Wang, L.; /SLAC

2011-12-14T23:59:59.000Z

356

Energy Efficient Steam Trapping of Trace Heating Systems  

E-Print Network (OSTI)

Since as many as 40-60% of a plant's steam traps may be used on steam tracer lines, it is essential to select the correct, properly sized 'traps'; to optimize the efficient removal of condensate while providing maximum heat transfer to maintain desired product temperatures and greatly reduce steam losses. Factors related to achieving uniform product temperatures and maximum heat transfer rates and energy efficiency are: 1.Types and Methods used for Steam Tracing; 2. Systematic heat balance required to achieve economic tracer lengths; 3. Maximum allowable trapping distance for specific applications 4.Data important to determine condensate loads; 5. Trap selection, sizing, good installation practices, and proper maintenance. Using an engineered approach to steam trapping of trace heating systems have resulted in stable tracer line temperatures while reducing steam consumption 10-50% with minimum maintenance.

Krueger, R. G.; Wilt, G. W.

1981-01-01T23:59:59.000Z

357

Extension of the Focusable Mass Range in Distance-of-Flight Mass Spectrometry with Multiple Detectors  

SciTech Connect

Since the underlying theory of Distance-of-Flight Mass Spectrometry (DOFMS) was reported in 2007,[1] laboratory results[2, 3] have proven its practical viability. However, these previous implementations of DOFMS considered ion detection only over narrow DOF-detection windows, with 25-mm being the greatest detection length explored. These small mass windows cannot be used to evaluate how DOFMS focusing performs over greater DOF detection lengths and mass ranges. In the present study, we expand on previous studies by placing two spatially selective ion detectors along the detection plane of the DOFMS instrument. Ion signals are simultaneously collected from both DOF detectors in order to simulate DOFMS performance with a longer spatially selective ion detector.

Gundlach-Graham, Alexander W.; Dennis, Elise; Ray, Steven J.; Enke, Christie G.; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

2012-11-15T23:59:59.000Z

358

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

DOE Green Energy (OSTI)

Some years ago it was suggested that halogen negative ions [1]could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion - ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component - positive ions, negative ions, and electrons -- can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion-ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed.

Grisham, L.R.; Kwan, J.W.

2008-08-01T23:59:59.000Z

359

Quantum analysis of atom-ion sympathetic cooling in the presence of micromotion  

E-Print Network (OSTI)

We investigate the problem of a single ion in a radio-frequency trap and immersed in an ultracold Bose gas either in condensed or non-condensed phase. We develop master equation formalism describing the sympathetic cooling and we determine the cooling rates and final energies of ions. We show that cold atomic reservoir modifies the stability diagram of the ion in the Paul trap creating the regions where the ion is either cooled or heated due to the energy quanta exchanged with the time-dependent potential. Our calculation indicates that micromotion constitutes an important source of heating limiting the final temperature of ions to values higher than 100$\\mu$K for parameters of present experiments.

Michal Krych; Zbigniew Idziaszek

2013-12-01T23:59:59.000Z

360

Low pressure electrospray ionization system and process for effective transmission of ions  

Science Conference Proceedings (OSTI)

Systems and methods that provide up to complete transmission of ions between coupled stages with low effective ion losses. An "interfaceless" electrospray ionization system is further described that operates an electrospray at a reduced pressure such that standard electrospray sample solutions can be directly sprayed into an electrodynamic ion funnel which provides ion focusing and transmission of ions into a mass analyzer. Furthermore, chambers maintained at different pressures can allow for more optimal operating conditions for an electrospray emitter and an ion guide.

Tang, Keqi (Richland, WA); Page, Jason S (Kennewick, WA); Kelly, Ryan T (West Richland, WA); Smith, Richard D (Richland, WA)

2012-05-08T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
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361

Sample inlet tube for ion source  

DOE Patents (OSTI)

An improved inlet tube is positioned within an aperture through the device to allow the passage of ions from the ion source, through the improved inlet tube, and into the interior of the device. The inlet tube is designed with a larger end and a smaller end wherein the larger end has a larger interior diameter than the interior diameter of the smaller end. The inlet tube is positioned within the aperture such that the larger end is pointed towards the ion source, to receive ions therefrom, and the smaller end is directed towards the interior of the device, to deliver the ions thereto. Preferably, the ion source utilized in the operation of the present invention is a standard electrospray ionization source. Similarly, the present invention finds particular utility in conjunction with analytical devices such as mass spectrometers.

Prior, David [Hermiston, OR; Price, John [Richland, WA; Bruce, Jim [Oceanside, CA

2002-09-24T23:59:59.000Z

362

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator  

Science Conference Proceedings (OSTI)

Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped electron bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped electrons. Next, the sixth chapter introduces suggestions for future trapped electron experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to electron trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel plasma, which if produced could solve some of the remaining issues for a plasma-based collider.

Kirby, Neil; /SLAC

2009-10-30T23:59:59.000Z

363

Means for obtaining a metal ion beam from a heavy-ion cyclotron source  

DOE Patents (OSTI)

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Hudson, E.D.; Mallory, M.L.

1975-08-01T23:59:59.000Z

364

Improved ion source  

DOE Patents (OSTI)

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species,

Leung, K.N.; Ehlers, K.W.

1982-05-04T23:59:59.000Z

365

Using malaise traps to sample ground beetles (Coleoptera: Carabidae).  

SciTech Connect

Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and �¢����trap-shy�¢��� species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

Ulyshen, Michael D., James L. Hanula, and Scott Horn

2005-01-01T23:59:59.000Z

366

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, Mark L. (Livermore, CA); Davis, Jay C. (Livermore, CA)

1993-01-01T23:59:59.000Z

367

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, M.L.; Davis, J.C.

1993-02-23T23:59:59.000Z

368

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

This invention is comprised of an apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radiofrequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and {sup 3}He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, M.L.; Davis, J.C.

1991-12-31T23:59:59.000Z

369

Progress towards high precision measurements on ultracold metastable hydrogen and trapping deuterium  

E-Print Network (OSTI)

(cont.) not achieve deuterium trapping through helium-surface cooling. It is proposed that buffer gas loading can be used to cryogenically cool and trap deuterium.

Steinberger, Julia K., 1974-

2004-01-01T23:59:59.000Z

370

Double-well magnetic trap for Bose-Einstein condensates  

E-Print Network (OSTI)

We present a magnetic trapping scheme for neutral atoms based on a hybrid of Ioffe-Pritchard and Time-averaged Orbiting Potential traps. The resulting double-well magnetic potential has readily controllable barrier height and well separation. This offers a new tool for studying the behavior of Bose condensates in double-well potentials, including atom interferometry and Josephson tunneling. We formulate a description for the potential of this magnetic trap and discuss practical issues such as loading with atoms, evaporative cooling and manipulating the potential.

N. R. Thomas; C. J. Foot; A. C. Wilson

2001-08-10T23:59:59.000Z

371

Steam Trap Testing and Evaluation: An Actual Plant Case Study  

E-Print Network (OSTI)

With rising steam costs and a high failure rate on the Joliet Plants standard steam trap, a testing and evaluation program was begun to find a steam trap that would work at Olin-Joliet. The basis was to conduct the test on the actual process equipment and that a minimum life be achieved. This paper deals with the history of the steam system/condensate systems, the setting up of the testing procedure, which traps were and were not tested and the results of the testing program to date.

Feldman, A. L.

1981-01-01T23:59:59.000Z

372

Ion source based on the cathodic arc  

DOE Patents (OSTI)

A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

Sanders, D.M.; Falabella, S.

1994-02-01T23:59:59.000Z

373

Fuel traps: mapping stability via water association.  

DOE Green Energy (OSTI)

Hydrogen storage is a key enabling technology required for attaining a hydrogen-based economy. Fundamental research can reveal the underlying principles controlling hydrogen uptake and release by storage materials, and also aid in characterizing and designing novel storage materials. New ideas for hydrogen storage materials come from exploiting the properties of hydrophobic hydration, which refers to water s ability to stabilize, by its mode of association, specific structures under specific conditions. Although hydrogen was always considered too small to support the formation of solid clathrate hydrate structures, exciting new experiments show that water traps hydrogen molecules at conditions of low temperatures and moderate pressures. Hydrogen release is accomplished by simple warming. While these experiments lend credibility to the idea that water could form an environmentally attractive alternative storage compound for hydrogen fuel, which would advance our nation s goals of attaining a hydrogen-based economy, much work is yet required to understand and realize the full potential of clathrate hydrates for hydrogen storage. Here we undertake theoretical studies of hydrogen in water to establish a firm foundation for predictive work on clathrate hydrate H{sub 2} storage capabilities. Using molecular simulation and statistical mechanical theories based in part on quantum mechanical descriptions of molecular interactions, we characterize the interactions between hydrogen and liquid water in terms of structural and thermodynamic properties. In the process we validate classical force field models of hydrogen in water and discover new features of hydrophobic hydration that impact problems in both energy technology and biology. Finally, we predict hydrogen occupancy in the small and large cages of hydrogen clathrate hydrates, a property unresolved by previous experimental and theoretical work.

Rempe, Susan L.; Clawson, Jacalyn S.; Greathouse, Jeffery A.; Alam, Todd M; Leung, Kevin; Varma, Sameer; Sabo, Dubravko; Martin, Marcus Gary; Cygan, Randall Timothy

2007-03-01T23:59:59.000Z

374

Purple traps yield Reservation's first detection of Emerald Ash Borer  

NLE Websites -- All DOE Office Websites (Extended Search)

traps yield Reservation's first detection of Emerald Ash Borer traps yield Reservation's first detection of Emerald Ash Borer The question of whether or not DOE's forests are infested with Emerald Ash Borer (EAB) has been answered. On May 10, a trap on Highway 95 at the Highway 58 interchange produced the first instance of the destructive non-native insect in Roane County. Five days later, a second trap on Bethel Valley Road near the East Portal turned up the first capture in Anderson County. "Unfortunately, these finds signal the beginning of a decline of ash species throughout the reservation" according to Greg Byrd, forester with the ORNL Natural Resources Program. "Dieback will become more prominent as the insect populations expand. Native ash trees have little defense against this pest, which was

375

Energy Conservation in Coastal-Trapped Wave Calculations  

Science Conference Proceedings (OSTI)

A consideration of energy conservation for coastal-trapped waves shows that, for a slowly varying medium, the normalization of the wave modes is not arbitrary. Errors related to incorrect normalization are demonstrated for a simple analytic ...

K. H. Brink

1989-07-01T23:59:59.000Z

376

Energy Trapping near the Equator in a Numerical Ocean Model  

Science Conference Proceedings (OSTI)

The trapped equatorial standing modes described theoretically by Gent (1979) are reproduced in a single vertical-mode numerical ocean model. integrations are carried out in domains whose longitudinal extents are characteristic of the widths of ...

Peter R. Gent; Albert J. Semtner Jr.

1980-06-01T23:59:59.000Z

377

Trapped Lee Wave Interference in the Presence of Surface Friction  

Science Conference Proceedings (OSTI)

Trapped lee wave interference over double bell-shaped obstacles in the presence of surface friction is examined. Idealized high-resolution numerical experiments with the nonhydrostatic Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) ...

Ivana Stiperski; Vanda Grubiši?

2011-04-01T23:59:59.000Z

378

A Model for Vortex-Trapped Internal Waves  

Science Conference Proceedings (OSTI)

Regions of negative vorticity are observed to trap and amplify near-inertial internal waves, which are sources of turbulent mixing 10–100 times higher than typically found in the stratified ocean interior. Because these regions are of finite ...

Eric Kunze; Emmanuel Boss

1998-10-01T23:59:59.000Z

379

On the Damping of Free Coastal-Trapped Waves  

Science Conference Proceedings (OSTI)

A perturbative method is presented for estimating the decay time of subinertial coastal-trapped waves under a wide range of conditions where damping is relatively weak. Bottom friction is sometimes much more important than “long-wave” results ...

K. H. Brink

1990-08-01T23:59:59.000Z

380

Life Cycle of a Linear Coastal-Trapped Disturbance  

Science Conference Proceedings (OSTI)

A recent climatology of observed coastal-trapped disturbances in the marine atmospheric boundary layer along the United States west coast motivates the detailed examination, for a specific form of imposed forcing, of a linear shallow-water ...

R. M. Samelson; A. M. Rogerson

1996-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Light trapping limits in plasmonic solar cells: an analytical investigation  

E-Print Network (OSTI)

We analytically investigate the light trapping performance in plasmonic solar cells with Si/metallic structures. We consider absorption enhancements for surface plasmon polaritons (SPPs) at planar Si/metal interfaces and ...

Sheng, Xing

382

Novel trapping techniques for shaping Bose-Einstein condensates  

E-Print Network (OSTI)

A combination of radio frequency radiation and magnetic field gradients was used to trap atoms in dressed states. In a magnetic field with a quadrupole minimum. RF fields resonant with the (I F. m)) 11. -1) -- 1, 0) ...

Boyd, Micah (Micah Scott)

2007-01-01T23:59:59.000Z

383

Dissipative trapped electron modes in ell = 2 torsatrons  

SciTech Connect

Trapped electron modes in stellarators can be more unstable than those in tokamaks. They could be easier to detect in a stellarator and may be responsible for anomalous losses in the low collisionality regime. 5 refs., 1 fig.

Carreras, B.A.; Dominguez, N.; Lynch, V.E. (Oak Ridge National Lab., TN (USA)); Diamond, P.H. (California Univ., San Diego, CA (USA))

1989-01-01T23:59:59.000Z

384

Laser-driven Sisyphus cooling in an optical dipole trap  

Science Conference Proceedings (OSTI)

We propose a laser-driven Sisyphus-cooling scheme for atoms confined in a far-off resonance optical dipole trap. Utilizing the differential trap-induced ac Stark shift, two electronic levels of the atom are resonantly coupled by a cooling laser preferentially near the trap bottom. After absorption of a cooling photon, the atom loses energy by climbing the steeper potential, and then spontaneously decays preferentially away from the trap bottom. The proposed method is particularly suited to cooling alkaline-earth-metal-like atoms where two-level systems with narrow electronic transitions are present. Numerical simulations for the cases of {sup 88}Sr and {sup 174}Yb demonstrate the expected recoil and Doppler temperature limits. The method requires a relatively small number of scattered photons and can potentially lead to phase-space densities approaching quantum degeneracy in subsecond time scales.

Ivanov, Vladyslav V.; Gupta, Subhadeep [Physics Department, University of Wisconsin, Madison, Wisconsin 53706 (United States); Physics Department, University of Washington, Seattle, Washington 98195 (United States)

2011-12-15T23:59:59.000Z

385

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

E-Print Network (OSTI)

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.

A. P. Serebrov; V. E. Varlamov; A. G. Kharitonov; A. K. Fomin; Yu. N. Pokotilovski; P. Geltenbort; I. A. Krasnoschekova; M. S. Lasakov; R. R. Taldaev; A. V. Vassiljev; O. M. Zherebtsov

2007-02-06T23:59:59.000Z

386

Laser cooling in the Penning trap: an analytical model for cooling rates in the presence of an axializing field  

E-Print Network (OSTI)

Ions stored in Penning traps may have useful applications in the field of quantum information processing. There are, however, difficulties associated with the laser cooling of one of the radial motions of ions in these traps, namely the magnetron motion. The application of a small radio-frequency quadrupolar electric potential resonant with the sum of the two radial motional frequencies has been shown to couple these motions and to lead to more efficient laser cooling. We present an analytical model that enables us to determine laser cooling rates in the presence of such an 'axializing' field. It is found that this field leads to an averaging of the laser cooling rates for the two motions and hence improves the overall laser cooling efficiency. The model also predicts shifts in the motional frequencies due to the axializing field that are in qualitative agreement with those measured in recent experiments. It is possible to determine laser cooling rates experimentally by studying the phase response of the cooled ions to a near resonant excitation field. Using the model developed in this paper, we study the expected phase response when an axializing field is present.

R. J. Hendricks; E. S. Phillips; D. M. Segal; R. C. Thompson

2007-09-24T23:59:59.000Z

387

Review of ion accelerators  

Science Conference Proceedings (OSTI)

The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

Alonso, J.

1990-06-01T23:59:59.000Z

388

GYRAC?D?O: Relativistic plasma accumulator and ion accelerator  

Science Conference Proceedings (OSTI)

Plasma heating and relativistic plasma accumulation are realized in the GYRAC?D?O installation. Relativistic plasma accumulation is a result of plasma heating under synchrotron gyromagnetic autoresonance (SGA) and subsequent throwing of the SGA plasma into the central region of the magnetic mirror trap in the regime of the SGA?pulse packet. The optimum of the initial plasma pulsed injection is found. The obtained plasma is e?vortex filled with ions. Major parameters of the plasma are as follows: n ? 8 × 109 cm?3: average energy of electrons W?200 keV; lifetime ??40 ms. The problem of the plasma ejection out of the trap after the accumulation cycle completion is discussed. It is shown that effective plasma ejection and ion acceleration are possible in case of a relatively dense plasma which is feasible only in the accumulation regime.

V. V. Andreev; A. A. Apraksin; A. M. Umnov

1992-01-01T23:59:59.000Z

389

Plant View On Reducing Steam Trap Energy Loss  

E-Print Network (OSTI)

Energy will continue to be an ever increasingly important factor in the cost of doing business in the decade of the 80' s. In many petrochemical industries, energy is the second most costly item in producing a product. About 36% of our nation's total energy consumption is used by industry in producing the goods which are consumed around the world. Steam is the most commonly used energy source for the petrochemical industry. Most of this steam is used for heating and evaporating the many petrochemical liquids. This steam is then condensed and is removed from the system at the same rate as it is being formed or the loss of heat transfer will result. From a cost standpoint only condensate should be allowed through the trap. But at many plants half of the steam traps are passing excess steam. This is caused by neglect of aged steam traps which have worn out and misapplication of steam traps by oversizing or using the 'wrong' type trap. Elimination of steam wastes by an effective well engineered steam trap program is what is covered by this article.

Vallery, S. J.

1982-01-01T23:59:59.000Z

390

Quenching Collisions of Low-Energy Metastable Multiply-Charged Argon Ions  

E-Print Network (OSTI)

Quenching rates have been measured for selected metastable levels of Ar(q+) ions (q = 2, 3, 9, and 10) stored in a Kingdon ion trap, with mean energies of 262q eV and 181q eV. Effective quenching cross sections derived from these rates are found to be comparable to electron-capture cross sections of Ar(q+)-Ar collisions studied independently using ion-beam techniques. This implies that quenching is dominated by electron-capture collisions which change the ion charge state.

Church, David A.; Yang, L. S.; Tu, S. G.

1994-01-01T23:59:59.000Z

391

Negative ion beam injection apparatus with magnetic shield and electron removal means  

DOE Patents (OSTI)

A negative ion source is constructed to produce H.sup.- ions without using Cesium. A high percentage of secondary electrons that typically accompany the extracted H.sup.- are trapped and eliminated from the beam by permanent magnets in the initial stage of acceleration. Penetration of the magnetic field from the permanent magnets into the ion source is minimized. This reduces the destructive effect the magnetic field could have on negative ion production and extraction from the source. A beam expansion section in the extractor results in a strongly converged final beam.

Anderson, Oscar A. (Berkeley, CA); Chan, Chun F. (Hayward, CA); Leung, Ka-Ngo (Hercules, CA)

1994-01-01T23:59:59.000Z

392

Apparatus And Method For Hydrogen And Oxygen Mass Spectrometry...  

NLE Websites -- All DOE Office Websites (Extended Search)

Of The Terrestrial Magnetosphere A detector element for mass spectrometry of a flux of heavy and light ions. Available for thumbnail of Feynman Center (505) 665-9090 Email...

393

EXPERIMENTAL RESULTS ON TRAPPING A GUN PLASMA IN TORMAC P-l  

SciTech Connect

A start-up scheme for producing a plasma in the biscusp field configuration of TORMAC which involves the radial injection and trapping of a toroidal gun plasma is described. The peloidal field of the external cusp coils acts as a barrier to the outward travel of the plasma ring. Interferometry and magnetic probe measurements observed the stopping of the expanding plasma ring which has a velocity of 17 cm/{micro}sec. Once stopped, the fields are arranged to hold the plasma in a magnetic well. Interferometry measurements observed a well defined outer boundary remaining stationary during the 20 {micro}sec of the measurement. The inner boundary was also in evidence as shown particularly by the particle flux distribution emanating from the cusp region. The indications are that a sheath exists having a width of 1 to 1.5 ion gyro radii in the poloidial field. Measurements of Thomson and interferometry give a T{sub e} of 15eV, a 15 {micro}sec density decay time, and a 5 {micro}sec energy decay time. These results show that this injection and trapping method is successful, and thus a higher gun plasma energy combined with a flux conserving barrier may lead to higher temperatures for testing containment in TORMAC.

Pincosy, P.A.; Myers, B.R.; Levine, M.A.; Feinberg, B.; Niland, R.A.; Soroka, L.

1981-07-01T23:59:59.000Z

394

Nuclear-spin dependent parity violation in diatomic molecular ions  

E-Print Network (OSTI)

Nuclear-spin-dependent (NSD) parity violating (PV) effects can be strongly enhanced in diatomic molecules containing heavy atoms. Future measurements are anticipated to provide nuclear anapole moments and strength constants for PV nuclear forces. In light molecules, the NSD electroweak electron-nucleus interaction may also be detected. Here we calculate NSD PV effects for molecular ions. Our calculations are motivated by rapid developments in trapping techniques for such systems at low temperatures.

Borschevsky, A; Dzuba, V A; Beloy, K; Flambaum, V V; Schwerdtfeger, P A

2012-01-01T23:59:59.000Z

395

Investigation of Aging Mechanisms in Lean NOx Traps  

Science Conference Proceedings (OSTI)

Lean NO{sub x} traps (LNTs) represent a promising technology for the abatement of NO{sub x} under lean conditions. Although LNTs are starting to find commercial application, the issue of catalyst durability remains problematic. LNT susceptibility to sulfur poisoning is the single most important factor determining effective catalyst lifetime. The NO{sub x} storage element of the catalyst has a greater affinity for SO{sub 3} than it does for NO{sub 2}, and the resulting sulfate is more stable than the stored nitrate. Although this sulfate can be removed from the catalyst by means of high temperature treatment under rich conditions, the required conditions give rise to deactivation mechanisms such as precious metal sintering, total surface area loss, and solid state reactions between the various oxides present. The principle objective of this project was to improve understanding of the mechanisms of lean NO{sub x} trap aging, and to understand the effect of washcoat composition on catalyst aging characteristics. The approach utilized involved detailed characterization of model catalysts prior to and after aging, in tandem with measurement of catalyst performance in NO{sub x} storage and reduction. In this manner, NO{sub x} storage and reduction characteristics were correlated with the evolution of catalyst physico-chemical properties upon aging. Rather than using poorly characterized proprietary catalysts, or simple model catalysts of the Pt/BaO/Al{sub 2}O{sub 3} type (representing the first generation of LNTs), Pt/Rh/BaO/Al{sub 2}O{sub 3} catalysts were employed which also incorporated CeO{sub 2} or CeO{sub 2}-ZrO{sub 2}, representing a model system which more accurately reflects current LNT formulations. Catalysts were prepared in which the concentration of each of the main components was systematically varied: Pt (50, 75 or 100 g/ft{sup 3}), Rh (10 or 20 g/ft{sup 3}), BaO (15, 30 or 45 g/L), and either CeO{sub 2} (0, 50 or 100 g/L) or CeO{sub 2}-ZrO{sub 2} (0, 50 or 100 g/L). A high surface area La-stabilized alumina was used to support the BaO phase. Catalysts were obtained by washcoating onto standard cordierite substrates, the total washcoat loading being set at 260 g/L. La-stabilized alumina was used as the balance. Subsequent to de-greening, the NO{sub x} storage and reduction characteristics of the catalysts were evaluated on a bench reactor, after which the catalysts were aged on a bench reactor to the equivalent of ca. 75,000 miles of road aging using a published accelerated aging protocol. The aged catalysts were then subjected to the same evaluation proecdure used for the de-greened catalysts. In addition to the use of standard physico-chemical analytical techniques for studying the fresh and aged model catalysts, use was made of advanced analytical tools for characterizing their NO{sub x} storage/reduction and sulfation/desulfation characteristics, such as Spatially resolved capillary-inlet Mass Spectrometry (SpaciMS) and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS).

Mark Crocker

2010-03-31T23:59:59.000Z

396

Trapping of antiprotons -- a first step on the way to antihydrogen  

DOE Green Energy (OSTI)

A first step towards producing and effectively utilizing antihydrogen atoms consists of trapping antiprotons. The immediate next step must then be to control, i.e. trap the produced antihydrogen. The current state of the art in trapping antiprotons and positrons is reviewed, and the challenges in trapping the resulting neutral particles are discussed.

Holzscheiter, M.H.

1993-07-01T23:59:59.000Z

397

Near-ground-state transport of trapped-ion qubits through a ...  

Science Conference Proceedings (OSTI)

... an additional step was used to convert the rf ... examined a technique for transferring energy between motional ... [40] K. Mřlmer and A. Sřrensen, Phys. ...

2011-10-18T23:59:59.000Z

398

Single-qubit-gate error below 10 in a trapped ion  

Science Conference Proceedings (OSTI)

... computers depends on the ability to accurately control sensitive super- position amplitudes by ... near 1.25 GHz, coupled with a 4-nF capacitor to one ...

2011-10-28T23:59:59.000Z

399

Intercontinental quantum liaisons between entangled electrons in ion traps of thermoluminescent crystals  

E-Print Network (OSTI)

The experiments reported in this paper were carried out with space-separated entangled thermoluminescent dosimetry (TLD) crystals in Baton Rouge, Louisiana (USA) and Givarlais (France) at 8,182 km between entangled samples. Samples consisted of doped lithium fluoride TLD's that were simultaneously irradiated in pairs together at one location by Bremsstrahlung radiation generated by a Varian CLINAC unit. One of the paired TLD crystals was then mailed to Baton Rouge and its entangled counterpart remained in Givarlais. The crystal in Baton Rouge (master) was then subjected to thermal stimulation which elicited a measurable light emission response in the counterpart (slave) under a photomultiplier in Givarlais. Highly correlated passive light emissions were observed in the nonheated slave TLD while the master TLD was ramped up in temperature and then allowed to cool to ambient temperature. Maximum correlations in the slave TLD light emissions were observed at the turn around temperature which is the point where the master TLD temperature is allowed to decrease. The experimenter in Girvalais was thus able to determine with high accuracy the point in time at which the master TLD heating oven was turned off (turn around point) without any communication between the experimenters during the heating-cooling phase of the experiment. The implications of these observed results are of great significance for quantum communication technology.

Robert Desbrandes; Daniel Van Gent

2006-11-10T23:59:59.000Z

400

Nanoscale interfacial structure for Novel Opto-electronic and Ion-trapping Devices  

E-Print Network (OSTI)

delay after the optical trigger event is almost a constantreceives an optical trigger event, the system starts readingoptical encoder triggers events in the pattern generator.

Ulin-Avila, Erick

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Architecture for a large-scale ion-trap quantum computer  

Science Conference Proceedings (OSTI)

... Preprint quant-ph/0205094 at khttp://xxx.lanl.govl (2002). 26. ... Preprint quant-ph/0112084 at khttp://xxx.lanl.govl (2001). 32. ...

2010-09-15T23:59:59.000Z

402

RECENT EXPERIMENTS ON TRAPPED IONS AT THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY  

E-Print Network (OSTI)

the storage cell, and the Lambda Wheels are mounted inside the pumping cross in front of the scattering experiment. A wheel­shaped array of silicon counters placed in between the storage cell and the first flowing through a thin­walled storage cell. The deep­inelastic scatter­ ing events are observed

403

NlST Technical Note 1353 Trapped Ions and Laser Cooling 111  

E-Print Network (OSTI)

. Alicyclobacillus vulcanalis sp. nov., a new thermophilic, acidophilic bacterium isolated from Coso Hot Springs evapotranspiration captured by seasonally pumping wells in river valleys. Journal of Hydrology 318: 334-347. · Wen, F

404

An investigation of precision and scaling issues in nuclear spin and trapped-ion quantum simulators  

E-Print Network (OSTI)

Quantum simulation offers the possibility of using a controllable quantum-mechanical system to implement the dynamics of another quantum system, performing calculations that are intractable on classical computers for all ...

Clark, Robert J., Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

405

Sympathetic Cooling of 4 Ions in a Radio-Frequency Trap  

E-Print Network (OSTI)

interesting perspectives for performing precision tests of QED and measurements of nuclear radii. This Letter) as input. Precise values of the He nuclear radii can test theoretical nuclear methods and force models experimental uncertainty test the nuclear and the recently improved theoretical QED contributions

Schiller, Stephan

406

An Investigation of Precision and Scaling Issues in Nuclear Spin and Trapped-Ion Quantum Simulators  

E-Print Network (OSTI)

be appreciably larger than in existing intermediate size scale experiments. As a consequence there may be a lower in intermediate size experiments. Also, there may be a turbulent "sea" of high-n modes which is not encountered in present intermediate size experiments. Another important effect of energetic alpha particles

Raizen, Mark G.

407

System and method for trapping and measuring a charged particle in a liquid  

DOE Patents (OSTI)

A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

2013-07-23T23:59:59.000Z

408

Intrinsic Amino Acid Size Parameters from a Series of 113 Lysine-Terminated Tryptic Digest Peptide Ions  

E-Print Network (OSTI)

by electrospray ionization have been measured by a new ion mobility/time-of-flight mass spectrometry technique have been reported.2,4 We have recently developed a new ion mobility/time-of-flight method that makes and analyzed using an ion mobility/time-of-flight mass spectrometry method that allows drift times (mobilities

Clemmer, David E.

409

Impact of nonaqueous phase liquid (NAPL) source zone architecture on mass removal mechanisms in strongly layered heterogeneous porous media during soil vapor extraction  

Science Conference Proceedings (OSTI)

An existing multiphase flow simulator was modified in order to determine the effects of four mechanisms on NAPL mass removal in a strongly layered heterogeneous vadose zone during soil vapor extraction (SVE): a) NAPL flow, b) diffusion and dispersion from low permeability zones, c) slow desorption from sediment grains, and d) rate-limited dissolution of trapped NAPL. The impact of water and NAPL saturation distribution, NAPL type (i.e., free, residual, or trapped) distribution, and spatial heterogeneity of the permeability field on these mechanisms were evaluated. Two different initial source zone architectures (one with and one without trapped NAPL) were considered and these architectures were used to evaluate seven different SVE scenarios. For all runs, slow diffusion from low permeability zones that gas flow bypassed was a dominant factor for diminished SVE effectiveness at later times. This effect was more significant at high water saturation due to the decrease of gas-phase relative permeability. Transverse dispersion contributed to fast NAPL mass removal from the low permeability layer in both source zone architectures, but longitudinal dispersion did not affect overall mass removal time. Both slow desorption from sediment grains and rate-limited mass transfer from trapped NAPL only marginally affected removal times. However, mass transfer from trapped NAPL did affect mass removal at late time, as well as the NAPL distribution. NAPL flow from low to high permeability zones contributed to faster mass removal from the low permeability layer, and this effect increased when water infiltration was eliminated. These simulations indicate that if trapped NAPL exists in heterogeneous porous media, mass transfer can be improved by delivering gas directly to zones with trapped NAPL and by lowering the water content, which increases the gas relative permeability and changes trapped NAPL to free NAPL.

Yoon, Hongkyu; Werth, Charlie; Valocchi, Albert J.; Oostrom, Martinus

2008-09-26T23:59:59.000Z

410

Dust ion-acoustic shock waves in charge varying dusty plasmas with electrons having vortexlike velocity distribution  

Science Conference Proceedings (OSTI)

A weakly nonlinear analysis is carried out to investigate the properties of dust ion-acoustic shock waves in a charge varying dusty plasma with vortexlike electron distribution. We use the ionization model, hot ions with equilibrium streaming speed and a trapped electron charging current derived from the well-known orbit limited motion theory. A new modified Burger equation is derived. Besides nonlinear trapping, this equation involves two kinds of dissipation (the anomalous one inherent to nonadiabatic dust charge fluctuation and the one due to the particle loss and ionization). These two kinds of dissipation can act concurrently. The traveling wave solution has been acquired by employing the modified extended tanh-function method. The shocklike solution is numerically analyzed based on the typical numerical data from laboratory dusty plasma devices. It is found that ion temperature, trapped particles, and weak dissipations significantly modify the shock structures.

Alinejad, H. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441, Maragha 55177-36698 (Iran, Islamic Republic of); Tribeche, M. [Plasma Physics Group (PPG), Theoretical Physics Laboratory (TPL), Faculty of Science-Physics, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers (Algeria)

2010-12-15T23:59:59.000Z

411

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http://www.personal.kent.edu/~slee19/)  

E-Print Network (OSTI)

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http ionization mass spectrometry (PTR-CIMS). A typical CIMS instrument can be constructed from an ion source, an ion molecular reactor, and a quadrupole mass spectrometer. Shown below is schematic diagram of a CIMS

Lee, Shan-Hu

412

Mass and Lifetime Measurements in Storage Rings  

Science Conference Proceedings (OSTI)

Masses of nuclides covering a large area of the chart of nuclides can be measured in storage rings where many ions circulate at the same time. In this paper the recent progress in the analysis of Schottky mass spectrometry data is presented as well as the technical improvements leading to higher accuracy for isochronous mass measurements with a time-of-flight detector. The high sensitivity of the Schottky method down to single ions allows to measure lifetimes of nuclides by observing mother and daughter nucleus simultaneously. In this way we investigated the decay of bare and H-like 140Pr. As we could show the lifetime can be even shortened compared to those of atomic nuclei despite of a lower number of electrons available for internal conversion or electron capture.All these techniques will be implemented with further improvements at the storage rings of the new FAIR facility at GSI in the future.

Weick, H.; Beckert, K.; Beller, P.; Bosch, F.; Dimopoulou, C.; Kozhuharov, C.; Kurcewicz, J.; Mazzocco, M.; Nociforo, C.; Nolden, F.; Steck, M.; Sun, B.; Winkler, M. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); Brandau, C.; Chen, L.; Geissel, H.; Knoebel, R.; Litvinov, S. A.; Litvinov, Yu. A.; Scheidenberger, C. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); II. Phys. Institut, Justus-Liebig-Universitaet Giessen, 35392 Giessen (Germany)] (and others)

2007-05-22T23:59:59.000Z

413

Trapped electron losses by interactions with coherent VLF waves  

SciTech Connect

VLF whistler waves from lightning enter the magnetosphere and cause the precipitation of energetic trapped electrons by pitch angle scattering. These events, known as Lightning-induced Electron Precipitation (LEP) have been detected by satellite and rocket instruments and by perturbations of VLF waves traveling in the earth-ionosphere waveguide. Detailed comparison of precipitating electron energy spectra and time dependence are in general agreement with calculations of trapped electron interactions with ducted whistler waves. In particular the temporal structure of the precipitation and the dynamic energy spectra of the electrons confirm this interpretation of the phenomena. There are discrepancies between observed and measured electron flux intensities and pitch angle distributions, but these quantities are sensitive to unknown wave intensities and trapped particle fluxes near the loss cone angle. The overall effect of lightning generated VLF waves on the lifetime of trapped electrons is still uncertain. The flux of electrons deflected into the bounce loss cone by a discrete whistler wave has been measured in a few cases. However, the area of the precipitation region is not known, and thus the total number of electrons lost in an LEP event can only be estimated. While the LEP events are dramatic, more important effects on trapped electrons may arise from the small but numerous deflections which increase the pitch angle diffusion rate of the electron population. {copyright} {ital 1996 American Institute of Physics.}

Walt, M.; Inan, U.S. [Space, Telecommunications and Radioscience Laboratory, Stanford University, Stanford, California (United States); Voss, H.D. [Lockheed Missiles and Space Co. (United States)

1996-07-01T23:59:59.000Z

414

Cosmological perturbations from inhomogeneous preheating and multi-field trapping  

E-Print Network (OSTI)

We consider inhomogeneous preheating in a multi-field trapping model. The curvature perturbation is generated by inhomogeneous preheating which induces multi-field trapping at the enhanced symmetric point (ESP), and results in fluctuation in the number of e-foldings. Instead of considering simple reheating after preheating, we consider a scenario of shoulder inflation induced by the trapping. The fluctuation in the number of e-foldings is generated during this weak inflationary period, when the additional light scalar field is trapped at the local maximum of its potential. The situation may look similar to locked or thermal inflation or even to hybrid inflation, but we will show that the present mechanism of generating the curvature perturbation is very different from these others. Unlike the conventional trapped inflationary scenario, we do not make the assumption that an ESP appears at some unstable point on the inflaton potential. This assumption is crucial in the original scenario, but it is not important in the multi-field model. We also discuss inhomogeneous preheating at late-time oscillation, in which the magnitude of the curvature fluctuation can be enhanced to accommodate low inflationary scale.

Tomohiro Matsuda

2007-07-04T23:59:59.000Z

415

Plasma ion sources and ion beam technology in microfabrications  

E-Print Network (OSTI)

5 Ion source for metallic ion beam generation and thin filmnew plasma source for metallic ion beam generation and metal5: Ion source for metallic ion beam generation and thin film

Ji, Lili

2007-01-01T23:59:59.000Z

416

Effects of plasma particle trapping on dust-acoustic solitary waves in an opposite polarity dust-plasma medium  

SciTech Connect

Dust acoustic solitary waves in a dusty plasma containing dust of opposite polarity (adiabatic positive and negative dust), non-isothermal electrons and ions (following vortex like distribution) are theoretically investigated by employing pseudo-potential approach, which is valid for arbitrary amplitude structures. The propagation of small but finite amplitude solitary structures is also examined by using the reductive perturbation method. The basic properties of large (small) amplitude solitary structures are investigated by analyzing the energy integral (modified Korteweg-de Vries equation). It is shown that the effects of dust polarity, trapping of plasma particles (electrons and ions), and temperatures of dust fluids significantly modify the basic features of the dust-acoustic solitary structures that are found to exist in such an opposite polarity dust-plasma medium. The relevance of the work in opposite polarity dust-plasma, which may occur in cometary tails, upper mesosphere, Jupiter's magnetosphere, is briefly discussed.

Ahmad, Zulfiqar [Institute of Physics and Electronics, University of Peshawar, 25000 Peshawar (Pakistan); Mushtaq, A. [Department of Physics, Abdul Wali Khan University, Mardan 23200 (Pakistan); National Center for Physics, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mamun, A. A. [Department of Physics, Jahangirnagar University Savar, Dhaka 1342 (Bangladesh)

2013-03-15T23:59:59.000Z

417

Recent progress in tailoring trap-based positron beams  

SciTech Connect

Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States)

2013-03-19T23:59:59.000Z

418

Photoelectron spectroscopy of negative ions  

Science Conference Proceedings (OSTI)

Ultraviolet photoelectron spectroscopy of negative ions was used to probe the anionic and neutral states of the halogen monoxides, halogen dioxides, halocarbenes, and fluorovinylidene species. Ions, created in a flowing afterglow source, were mass selected and photodetached by continuous monochromatic laser radiation, and the kinetic energy of the photodetached electrons were determined. The photoelectron spectra provide electronic and vibrational structure. Photoelectron spectra of the halogen monoxides yielded adiabatic electron affinities, neutral and anion frequencies, and spin-orbit splittings. Franck-Condon analyses provided the change in bond length between the neutral and anion species. Neutral heats of formation and dissociation energies were combined with electron affinities to determine anion heats of formation and dissociation energies. Adiabatic electron affinities, neutral vibrational frequencies and anion vibrational frequencies were determined from photoelectron spectra of OClO[sup [minus

Gilles, M.K.

1993-01-01T23:59:59.000Z

419

Formation of Antihydrogen Rydberg atoms in strong magnetic field traps  

SciTech Connect

It is shown that several features of antihydrogen production in nested Penning traps can be described with accurate and efficient Monte Carlo simulations. It is found that cold deeply-bound Rydberg states of antihydrogen (H-bar) are produced in three-body capture in the ATRAP experiments and an additional formation mechanism -Rydberg charge transfer-, particular to the nested Penning trap geometry, is responsible for the observed fast (hot) H-bar atoms. Detailed description of the numerical propagation technique for following extreme close encounters is given. An analytic derivation of the power law behavior of the field ionization spectrum is provided.

Pohl, T.; Sadeghpour, H. R. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 (United States)

2008-08-08T23:59:59.000Z

420

Electron Trapping in Shear Alfven Waves that Power the Aurora  

Science Conference Proceedings (OSTI)

Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth's geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfven waves, preventing immediate wave damping. As waves move to regions with larger v{sub Te}/v{sub A}, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfven waves and electrons that form aurora.

Watt, Clare E. J.; Rankin, Robert [University of Alberta, Edmonton, Alberta (Canada)

2009-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Ion-acoustic cnoidal wave and associated non-linear ion flux in dusty plasma  

Science Conference Proceedings (OSTI)

Using reductive perturbation method with appropriate boundary conditions, coupled evolution equations for first and second order potentials are derived for ion-acoustic waves in a collisionless, un-magnetized plasma consisting of hot isothermal electrons, cold ions, and massive mobile charged dust grains. The boundary conditions give rise to renormalization term, which enable us to eliminate secular contribution in higher order terms. Determining the non secular solution of these coupled equations, expressions for wave phase velocity and averaged non-linear ion flux associated with ion-acoustic cnoidal wave are obtained. Variation of the wave phase velocity and averaged non-linear ion flux as a function of modulus (k{sup 2}) dependent wave amplitude are numerically examined for different values of dust concentration, charge on dust grains, and mass ratio of dust grains with plasma ions. It is found that for a given amplitude, the presence of positively (negatively) charged dust grains in plasma decreases (increases) the wave phase velocity. This behavior is more pronounced with increase in dust concentrations or increase in charge on dust grains or decrease in mass ratio of dust grains. The averaged non-linear ion flux associated with wave is positive (negative) for negatively (positively) charged dust grains in the plasma and increases (decreases) with modulus (k{sup 2}) dependent wave amplitude. For given amplitude, it increases (decreases) as dust concentration or charge of negatively (positively) charged dust grains increases in the plasma.

Jain, S. L. [Poornima Group of Institution, Sitapura, Jaipur 302022 (India); Tiwari, R. S. [Regional College for Education, Research and Technology, Jaipur 302022 (India); Mishra, M. K. [Department of Physics, University of Rajasthan, Jaipur 302004 (India)

2012-10-15T23:59:59.000Z

422

Analysis of fission gas release kinetics by on-line mass spectrometry  

SciTech Connect

The release of fission gas (Xe and Kr) and helium out of nuclear fuel materials in normal operation of a nuclear power reactor can constitute a strong limitation of the fuel lifetime. Moreover, radioactive isotopes of Xe and Kr contribute significantly to the global radiological source term released in the primary coolant circuit in case of accidental situations accompanied by fuel rod loss of integrity. As a consequence, fission gas release investigation is of prime importance for the nuclear fuel cycle economy, and is the driven force of numerous R and D programs. In this domain, for solving current fuel behavior understanding issues, preparing the development of new fuels (e.g. for Gen IV power systems) and for improving the modeling prediction capability, there is a marked need for innovations in the instrumentation field, mainly for: . Quantification of very low fission gas concentrations, released from fuel sample and routed in sweeping lines. Monitoring of quick gas release variations by quantification of elementary release during a short period of time. Detection of a large range of atomic masses (e.g. H{sub 2}, HT, He, CO, CO{sub 2}, Ne, Ar, Kr, Xe), together with a performing separation of isotopes for Xe and Kr elements. Coupling measurement of stable and radioactive gas isotopes, by using in parallel mass spectrometry and gamma spectrometry techniques. To fulfill these challenging needs, a common strategy for analysis equipment implementation has been set up thanks to a recently launched collaboration between the CEA and the Univ. of Provence, with the technological support of the Liverpool Univ.. It aims at developing a chronological series of mass spectrometer devices based upon mass filter and 2D/3D ion traps with Fourier transform operating mode and having increasing levels of performances to match the previous challenges for out-of pile and in-pile experiments. The final objective is to install a high performance online mass spectrometer coupled to a gamma spectrometer in the fission product laboratory of the future Jules Horowitz Material Test Reactor. An intermediate step will consist of testing first equipment on an existing experimental facility in the LECA-STAR Hot Cell Laboratory of the CEA Cadarache. This paper presents the scientific and operational stakes linked to fission gas issues, resumes the current state of art for analyzing them in nuclear facilities, then presents the skills gathered through this collaboration to overcome technological bottlenecks. Finally it describes the implementation strategy in nuclear research facilities of the CEA Cadarache. (authors)

Zerega, Y.; Reynard-Carette, C. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Parrat, D. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Carette, M. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Brkic, B. [Univ. of Liverpool, Dept. of Electrical Engineering and Electronics, Liverpool L69 3BX (United Kingdom); Lyoussi, A.; Bignan, G. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Janulyte, A.; Andre, J. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Pontillon, Y.; Ducros, G. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Taylor, S. [Univ. of Liverpool, Dept. of Electrical Engineering and Electronics, Liverpool L69 3BX (United Kingdom)

2011-07-01T23:59:59.000Z

423

Ion effects in future circular and linear accelerators  

SciTech Connect

In this paper, the author discusses ion effects relevant to future storage rings and linear colliders. The author first reviews the conventional ion effects observed in present storage rings and then discusses how these effects will differ in the next generation of rings and linacs. These future accelerators operate in a new regime because of the high current long bunch trains and the very small transverse beam emittances. Usually, storage rings are designed with ion clearing gaps to prevent ion trapping between bunch trains or beam revolutions. Regardless, ions generated within a single bunch train can have significant effects. The same is true in transport lines and linacs, where typical vacuum pressures are relatively high. Amongst other effects, the author addresses the tune spreads due to the ions and the resulting filamentation which can severely limit emittance correction techniques in future linear colliders, the bunch-to-bunch coupling due to the ions which can cause a multi-bunch instability with fast growth rates, and the betatron coupling and beam halo creation which limit the vertical emittance and beam lifetimes.

Raubenheimer, T.O.

1995-05-01T23:59:59.000Z

424

Detection of Magnetically Trapped Neutrons: Liquid Helium as a Scintillator  

E-Print Network (OSTI)

by Daniel Nicholas McKinsey to The Department of Physics in partial fulfillment of the requirements February 2002 #12;c 2002 - Daniel Nicholas McKinsey All rights reserved. #12;To my parents #12;Thesis advisor Author John Morrissey Doyle Daniel Nicholas McKinsey Detection of Magnetically Trapped Neutrons

McKinsey, Daniel

425

Synthesis of Cold Antihydrogen in a Cusp Trap  

Science Conference Proceedings (OSTI)

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

Enomoto, Y.; Nagata, Y.; Kanai, Y.; Mohri, A. [RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama 351-0198 (Japan); Kuroda, N.; Kim, C. H.; Torii, H. A.; Fujii, K.; Ohtsuka, M.; Tanaka, K.; Matsuda, Y. [Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan); Michishio, K.; Nagashima, Y. [Department of Physics, Tokyo University of Science, Kagurazaka, Shinjuku, Tokyo 162-8601 (Japan); Higaki, H. [Graduate School of Advanced Sciences of Matter, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan); Corradini, M.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Venturelli, L.; Zurlo, N. [Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, Universita di Brescia and Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Brescia, 25133 Brescia (Italy)

2010-12-10T23:59:59.000Z

426

Manipulation and assembly of nanowires with holographic optical traps  

E-Print Network (OSTI)

We demonstrate that semiconductor nanowires measuring just a few nanometers in diameter can be translated, rotated, cut, fused and organized into nontrivial structures using holographic optical traps. The holographic approach to nano-assembly allows for simultaneous independent manipulation of multiple nanowires, including relative translation and relative rotation.

Ritesh Agarwal; Kosta Ladavac; Yael Roichman; Guiha Yu; Charles M. Lieber; David G. Grier

2005-09-12T23:59:59.000Z

427

Broad beam ion implanter  

DOE Patents (OSTI)

An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

428

Cold Reactive Collisions between Laser-Cooled Ions and Velocity-Selected Neutral Molecules  

Science Conference Proceedings (OSTI)

We report a new experimental method to study reactive ion-molecule collisions at very low temperatures. A source of laser-cooled ions in a linear Paul trap has been combined with a quadrupole-guide velocity selector to investigate the reaction of Ca{sup +} with CH{sub 3}F at collision energies E{sub coll}/k{sub B}{>=}1 K with single-particle sensitivity. The technique represents a general approach to study reactive collisions between ions and polar molecules over a wide temperature range down to the cold regime.

Willitsch, Stefan; Bell, Martin T.; Gingell, Alexander D.; Procter, Simon R.; Softley, Timothy P. [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA (United Kingdom)

2008-02-01T23:59:59.000Z

429

Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)  

Science Conference Proceedings (OSTI)

The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

2009-01-06T23:59:59.000Z

430

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents (OSTI)

The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

1996-01-01T23:59:59.000Z

431

Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy ion irradiation II  

SciTech Connect

This paper presents a theoretical study of the DNA damage due to the effect of the composite electric fields of H{sub 2}O{sup +} ions produced from the irradiation of a heavy ion onto a cell. It is found that a much larger number of electrons, which are produced from electron impact ionization, is trapped near the track of an incident ion in the case of C{sup 6+} ion irradiation with the energy of 3 MeV/u than that of proton irradiation. Therefore, the irradiation of carbon ions may produce a larger number of cluster DNA damage than that in the irradiation of protons. This may lead to the understanding of relative biological effectiveness (RBE).

Moribayashi, Kengo [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7, Umemidai, Kizugawa-city, 619-0215 (Japan) and Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe City, 610-0394 (Japan)

2012-07-11T23:59:59.000Z

432

Mercury's Protoplanetary Mass  

E-Print Network (OSTI)

Major element fractionation among chondrites has been discussed for decades as ratios relative to Si or Mg. Recently, by expressing ratios relative to Fe, I discovered a new relationship admitting the possibility that ordinary chondrite meteorites are derived from two components, a relatively oxidized and undifferentiated, primitive component and a somewhat differentiated, planetary component, with oxidation state like the highly reduced enstatite chondrites, which I suggested was identical to Mercury's complement of lost elements. Here, on the basis of that relationship, I derive expressions, as a function of the mass of planet Mercury and the mass of its core, to estimate the mass of Mercury's lost elements, the mass of Mercury's alloy and rock protoplanetary core, and the mass of Mercury's gaseous protoplanet. Although Mercury's mass is well known, its core mass is not, being widely believed to be in the range of 70-80 percent of the planet mass. For a core mass of 75 percent, the mass of Mercury's lost elements is about 1.32 times the mass of Mercury, the mass of the alloy and rock protoplanetary core is about 2.32 times the mass of Mercury, and the mass of the gaseous protoplanet of Mercury is about 700 times the mass of Mercury. Circumstantial evidence is presented in support of the supposition that Mercury's lost elements is identical to the planetary component of ordinary chondrite formation.

J. Marvin Herndon

2004-10-01T23:59:59.000Z

433

Z5, Effect of Traps Spatial Localization on GaN HEMT Static ...  

Science Conference Proceedings (OSTI)

Conference Tools for 2010 Electronic Materials Conference ... In this work we discuss how trap state formation during reverse gate-source and ... by means of the commercial DESSIS-ISE (Synopsis Inc.) simulator showed that acceptor traps

434

Observations of Seasonal Variations in Atmospheric Greenhouse Trapping and Its Enhancement at High Sea Surface Temperature  

Science Conference Proceedings (OSTI)

The correlation between observed values of atmospheric greenhouse trapping and sea surface temperature is found to vary seasonally. Atmospheric greenhouse trapping is defined here as the difference between infrared emissions from the earth's ...

Robert Hallberg; Anand K. Inamdar

1993-05-01T23:59:59.000Z

435

Use of Bullet Traps and Steel Targets - June 4, 2012 | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Use of Bullet Traps and Steel Targets - June 4, 2012 Use of Bullet Traps and Steel Targets - June 4, 2012 June 4, 2012 This supplement contains the currently approved document, Use...

436

Mechanisms for Fluorescence Blinking and Charge Carrier Trapping in Single Semiconductor Nanocrystals  

E-Print Network (OSTI)

Trapping Mechanisms in Single CdSe/ZnS Quantum Dots fromTrapping Mechanisms in Single CdSe/ZnS Quantum Dots fromintermittency of single CdSe/ZnS core/shell quantum dot

Cordones, Amy Ashbrook

2012-01-01T23:59:59.000Z

437

The Extension of Baroclinic Coastal-Trapped Wave Theory to Superinertial Frequencies  

Science Conference Proceedings (OSTI)

The problem of finding baroclinic coastal-trapped wave modes is generalized from subinertial to superinertial frequencies at which complete trapping can only occur in special cases. Modes are found by a numerical resonance searching method in ...

Andrew C. Dale; Toby J. Sherwin

1996-11-01T23:59:59.000Z

438

Secondary Ion Mass Spectrometry of Vapor-Liquid-Solid Grown,  

E-Print Network (OSTI)

photovoltaic cells,1-5 field-effect transistors,6,7 light-emitting diodes,8 photodetectors,9 and molecular sen

Heaton, Thomas H.

439

Mass Spectrometer for High Molecular Weight Ions and Charged Particles  

APPLICATIONS OF TECHNOLOGY: Biotechnology ; Structural biology ; Materials science studies of nanoparticles ; ADVANTAGES:

440

Aluminum ION Battery  

•Lower cost because of abundant aluminum resources ... Li-ion battery (LiC 6 - Mn 2 O 4) 106 4.0 424 Al-ion battery (Al - Mn 2 O 4) 400 2.65 1,060

Note: This page contains sample records for the topic "ion trap mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

at the same time. Capable of accelerating 70 trillion protons with every pulse, and heavy ions such as gold and iron, the AGS receives protons and other ions from the AGS...

442

High Resolution Ion Mobility Spectrometry with Increased Ion Transmission: Exploring the Analytical Utility of Periodic-Focusing DC Ion Guide Drift Cells  

E-Print Network (OSTI)

Drift tube ion mobility spectrometry (IMS) is a powerful, post-ionization separation that yields structural information of ions through an ion-neutral collision cross section. The ion-neutral collision cross section is governed by the collision frequency of the ion with the neutral drift gas. Consequently, ions of different size will have different collision frequencies with the gas and be separated in the drift cell. A significant challenge for IMS, however, is to separate ions with very similar collision cross sections, requiring higher resolution ion mobility spectrometers. Resolution in IMS is of utmost importance for the separation of complex mixtures, e.g. crude oil samples, proteolytic digests, positional isomers, and ion conformers. However, most methods employed to increase mobility resolution significantly decrease ion transmission through the mobility device. Herein, a periodic-focusing DC ion guide drift cell (PDC IG) is presented to display its potential capabilities for higher mobility resolution with increased ion transmission. The PDC IG utilizes unique electrode geometry compared to the conventional uniform field electrode design. Electrode geometry can be defined by the electrode inner diameter (d), thickness (t), and spacing (s). Specifically, the ratio of d : t : s is equal to, or very near, 1:1:1. The PDC IG electrode design creates a non-uniform (fringing) electric field-especially near the electrode walls. The design also causes variations in the radial electric field which provides an effective RF as ions move through the device and a radially confining effective potential that improves ion transmission through the device. In this dissertation the analytical utility of the PDC IG drift cell for ion mobility separations will be explored. The radial focusing properties of the device will be presented along with studies of electrode geometry and its effect on ion mobility resolution and ion transmission through the drift cell. PDC IG drift cell length is also examined to determine its effect on mobility resolution and ion transmission. Finally, the PDC IG drift cell device is coupled to an orthogonal-acceleration time-of-flight mass spectrometer as well as a modular, PDC IG drift cell being adapted to a commercial qTOF mass spectrometer for IM-MS experiments.

Blase, Ryan Christopher

2010-12-01T23:59:59.000Z

443

Negative ion generator  

DOE Patents (OSTI)

A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions. 8 figs.

Stinnett, R.W.

1984-05-08T23:59:59.000Z

444

Intense ion beam generator  

DOE Patents (OSTI)

Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation.

Humphries, Jr., Stanley (Ithaca, NY); Sudan, Ravindra N. (Ithaca, NY)

1977-08-30T23:59:59.000Z

445

Negative ion generator  

DOE Patents (OSTI)

A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions.

Stinnett, Regan W. (Albuquerque, NM)

1984-01-01T23:59:59.000Z

446

Evaluation of Sorbent Trap Materials and Methods for Flue Gas Mercury Measurement  

Science Conference Proceedings (OSTI)

Sorbent traps are used as an alternative to continuous mercury monitors (CMM) for measuring vapor phase mercury concentrations in stacks of coal-fired power plants and for relative accuracy test audits (RATAs) of CMMs. EPRI has an ongoing program of research on sorbent trap methods, evaluating the performance of sorbent materials and the methods used to measure mercury on the sorbent traps. This report presents results of two investigations targeted at evaluating the performance of sorbent trap methods f...

2009-02-16T23:59:59.000Z

447

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

E-Print Network (OSTI)

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.

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

2013-05-23T23:59:59.000Z

448

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

E-Print Network (OSTI)

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.

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

2013-01-01T23:59:59.000Z

449

Characterization of compounds by time-of-flight measurement utilizing random fast ions  

DOE Patents (OSTI)

An apparatus is described for characterizing the mass of sample and daughter particles, comprising a source for providing sample ions; a fragmentation region wherein a fraction of the sample ions may fragment to produce daughter ion particles; an electrostatic field region held at a voltage level sufficient to effect ion-neutral separation and ion-ion separation of fragments from the same sample ion and to separate ions of different kinetic energy; a detector system for measuring the relative arrival times of particles; and processing means operatively connected to the detector system to receive and store the relative arrival times and operable to compare the arrival times with times detected at the detector when the electrostatic field region is held at a different voltage level and to thereafter characterize the particles. Sample and daughter particles are characterized with respect to mass and other characteristics by detecting at a particle detector the relative time of arrival for fragments of a sample ion at two different electrostatic voltage levels. The two sets of particle arrival times are used in conjunction with the known altered voltage levels to mathematically characterize the sample and daughter fragments. In an alternative embodiment the present invention may be used as a detector for a conventional mass spectrometer. In this embodiment, conventional mass spectrometry analysis is enhanced due to further mass resolving of the detected ions. 8 figs.

Conzemius, R.J.

1989-04-04T23:59:59.000Z

450

Characterization of compounds by time-of-flight measurement utilizing random fast ions  

DOE Patents (OSTI)

An apparatus for characterizing the mass of sample and daughter particles, comprising a source for providing sample ions; a fragmentation region wherein a fraction of the sample ions may fragment to produce daughter ion particles; an electrostatic field region held at a voltage level sufficient to effect ion-neutral separation and ion-ion separation of fragments from the same sample ion and to separate ions of different kinetic energy; a detector system for measuring the relative arrival times of particles; and processing means operatively connected to the detector system to receive and store the relative arrival times and operable to compare the arrival times with times detected at the detector when the electrostatic field region is held at a different voltage level and to thereafter characterize the particles. Sample and daughter particles are characterized with respect to mass and other characteristics by detecting at a particle detector the relative time of arrival for fragments of a sample ion at two different electrostatic voltage levels. The two sets of particle arrival times are used in conjunction with the known altered voltage levels to mathematically characterize the sample and daughter fragments. In an alternative embodiment the present invention may be used as a detector for a conventional mass spectrometer. In this embodiment, conventional mass spectrometry analysis is enhanced due to further mass resolving of the detected ions.

Conzemius, Robert J. (Ames, IA)

1989-01-01T23:59:59.000Z