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Search Publications

NIST Authors in Bold

Displaying 901 - 925 of 3757

Isotopic Metrology of Carbon Dioxide. I. Interlaboratory Comparison and Empirical Modeling of Inlet Equilibration Time, Inlet Pressure, and Ion Source Conductance

June 1, 2003
Author(s)
R M. Verkouteren, C E. Allison, S A. Studley, K J. Leckrone
… were designed to explore the effects of sample size, ion source conductance, and inlet changeover equilibration … carbon dioxide, gas isotope ratio mass spectrometer, GIRMS, ion source materials, isotopic measurements … Modeling of Inlet Equilibration Time, Inlet Pressure, and Ion Source Conductance …

Scalable Entanglement of Trapped Ions

January 1, 2000
Author(s)
C Monroe, Q A. Turchette, D Kielpinski, B E. King, V Meyer, Wayne M. Itano, David J. Wineland, C J. Myatt, M A. Rowe, Christopher Langer, C A. Sackett
… state so far in a collection of four trapped atomic ions. Notably, we employ a technique that is readily scalable … Scalable Entanglement of Trapped Ions …

Far-from-equilibrium noise heating and laser cooling dynamics in radio-frequency Paul traps

April 23, 2019
Author(s)
A Maitra, Dietrich Leibfried, D. Ullmo, H. Landa
… to a detailed study of the stochastic dynamics of an ion in the different regimes of motion within an anharmonic … becoming diffusive (i.e. it is equally likely to cool the ion as it is to heat it), and also turning into an effective … heating. Such a mechanism implies that a high-energy ion would be easily lost from the trap despite being laser …

Spectroscopy Using Quantum Logic

July 29, 2005
Author(s)
Piet Schmidt, Till P. Rosenband, C. Langer, Wayne M. Itano, James C. Bergquist, David J. Wineland
… with trapped atomic ions, an auxillary "logic" ion provides sympathetic laser cooling, state initialization, … and detection for simultaneously trapped "spectroscopy" ion. Detection is achieved by applying a mapping operation on each ion, which results in a coherent transfer of the spectroscopy …

Unexpected Peaks in Tandem Mass Spectra due to Reaction of Product Ions with Water in Mass Spectrometer Collision Cells

December 15, 2014
Author(s)
Pedatsur Neta, Mahnaz Farahani, Yamil Simon, Yuxue Liang, Xiaoyu Yang, Stephen E. Stein
… While determining the fragmentation pathways of positive ions of drugs, pesticides, metabolites, and other compounds, … mass spectrometry, we noticed that certain product ions react with water in the collision cell. This reaction is … of species that cannot be formed from the precursor ions by known fragmentation pathways. As a result, tandem …

Ion-beam radiation damage to DNA by investigation of free radical formation and base damage

March 1, 2020
Author(s)
Melis Kant, Pawel Jaruga, Erdem Coskun, Samuel Ward, Alexander Stark, David Becker, Amitav Adhikary, Michael Sevilla, Miral M. Dizdar
… processes and DNA base products involved in Ne-22 ion- beam (ca. 1.4 GeV) radiation damage to hydrated (12 … x 1 mm) samples were stacked in a sample packet and then ion-beam irradiated at 77 K. Free radicals trapped in ion- beam irradiated DNA at 77 K were elucidated using ESR …

Field-induced dehydration and optimal ionic escape paths for C2N membranes

June 11, 2021
Author(s)
Miroslav Barabash, William Gibby, Dmitry Luchinsky, Binquan Luan, Alexander Smolyanitsky, Peter McClintock
… Most analytic theories describing electrostatically driven ion transport through water-filled nanopores assume that the … the specific field-induced phenomena arising during ion transport. Here we consider an atomistic model of electrostatically driven ion permeation through subnanoporous C2N membranes. We …

Frequency Comparison of Two High-Accuracy Al+ Optical Clocks

February 17, 2010
Author(s)
Chin-Wen Chou, David Hume, J.C. Koelemeij, David J. Wineland, Till P. Rosenband
… of 8.6e-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser-cool the Al+ ion and detect its quantum state. The frequency of the … atomic clock, optical clock, high accuracy, aluminum ion, quantum logic …

Quantum information processing and quantum control with trapped atomic ions

December 14, 2009
Author(s)
David J. Wineland
… The role of trapped atomic ions in the field of quantum information processing is … discuss some of the historical developments that enabled ions to enter the field and then summarize the basic … processing and quantum control with trapped atomic ions …

Isotopic Ratio Measurements by Time-of-Flight Secondary Ion Mass Spectrometry

July 1, 2001
Author(s)
Albert J. Fahey, S R. Messenger
… Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is often considered … synonymous with SIMS in the static limit where the ion fluence on the sample surface is so low that damage is … been ruled out. However, the high spatial resolution Ga+ ion beams typically used in ToF-SIMS make it a potentially …

Reinvestigation of the Microwave Spectrum of 2-Methylmalonaldehyde

January 11, 2008
Author(s)
Vadim V. Ilyushin, E A. Alekseev, Y C. Chou, Y-C Hsu, Jon T. Hougen, Francis J. Lovas, L B. Picaux
… (2-MMA) exists in the gas phase as a six-membered hydrogen-bonded ring [HO-CH=C(CH3)-CH=O] and exhibits two large-amplitude motions, an intramolecular hydrogen transfer and a methyl torsion. The former motion is interesting because transfer of the hydrogen atom from the hydroxyl to the carbonyl group induces …

Developments in the Ni-Nb-Zr Amorphous Alloy Membranes

March 1, 2016
Author(s)
S. Sarker, D. Chandra, M. Hirscher, M. Dolan, D. Isheim, J. Wermer, D. Viano, M. Baricco, Terrence J. Udovic, D. Grant, O. Palumbo, A. Paolone, R. Cantelli
… is necessary to deliver a high purity H 2 product. Hydrogen-selective alloy membranes are emerging as a viable … depending on the composition, can exhibit relatively high hydrogen permeability between 473 and 673 K. Here we review … Amorphous, Hydrogen Permeation, Membranes, Metallic Glass, Nickel, …

Porous Graphene Oxide Frameworks: Synthesis and Gas Sorption Properties

July 1, 2011
Author(s)
Gadipelli Srinivas, Jacob Burress, Jamie Ford, Taner Yildirim
… Both isosteric heat of adsorption (Q st ) and the adsorbed hydrogen capacity per surface area are twice as large as … interlayer spacing between graphene planes such that hydrogen molecules interact with both surfaces. Finally, our … Graphene Oxide, Covalent Porous Frameworks, Boronic Acids, Hydrogen Storage. …

Preparation of entangled states through Hilbert space engineering

September 28, 2016
Author(s)
Yiheng Lin, John P. Gaebler, Florentin Reiter, Ting R. Tan, Ryan S. Bowler, Yong Wan, Adam C. Keith, Emanuel Knill, Kevin Coakley, Dietrich Leibfried, David J. Wineland, Scott Glancy
… such as fluctuations in laser intensity and frequency, and ion-motion frequencies. …

Tunnel junction sensors for HCI-surface measurements at low kinetic energies

January 25, 2013
Author(s)
Joshua M. Pomeroy, Russell E. Lake
… created by particle surface interactions. Highly charged ion (HCI) produced nanofeatures have been the focus of our … due a direct vacuum connection to the NIST electron beam ion trap (EBIT). Using these sensors, we have been able to … Highly charged ions, electron beam ion trap, tunnel junction sensors, stopping power …

Ultrashallow Depth Profiling with Time-of-flight Secondary Ion Mass Spectrometry

January 1, 1994
Author(s)
J. Bennett, John A. Dagata
… Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an efficient, sensitive … of TOF-SIMS ultrashallow depth profiling is demonstrated ion GaAs substrates that were passivated with P2S5 solutions … Ultrashallow Depth Profiling with Time-of-flight Secondary Ion Mass Spectrometry …
Displaying 901 - 925 of 3757
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