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Search Publications

NIST Authors in Bold

Displaying 26 - 50 of 2903

Direct Imaging of Static and Dynamic Ion Cloud Distributions in an Electron Beam Ion Trap

February 1, 2000
Author(s)
James V. Porto
… directly image highly charged ions within an electron beam ion trap (EBIT). Using an intensified CCD camera, we have the capability to measure both static and dynamic ion cloud distributions. The technique provides information … by other methods. Static images can be used to determine ion temperatures and the degree of overlap between the …

A Chosen IV Related Key Attack on Grain-128a

July 24, 2013
Author(s)
Subhadeep Banik, Subhamoy Maitra, Santanu (. Sarkar, Meltem Sonmez Turan
… cipher Grain v1 and Grain-128, it is possible to find Key-IV pairs that generate shifted keystreams efficiently. Based … observation, Lee et al. presented a related-Key chosen IV attack on Grain v1 and Grain-128 in ACISP 2008. Later, the … As a result, the existing idea of related-Key chosen IV attack does not work on this new design. In this paper, we …

IREX IV: Part 1, Evaluation of Iris Identification Algorithms

July 11, 2013
Author(s)
George W. Quinn, Patrick J. Grother, Mei L. Ngan, James R. Matey
… IREX IV aims to provide a fair and balanced scientific evaluation … performance of automated iris recognition algorithms. IREX IV evaluated the performance of 66 identification (i.e. … submitted by 12 companies and universities. IREX IV investigated the use of cost models for …

Charge States of y Ions in the Collision-Induced Dissociation of Doubly Charged Tryptic Peptide Ions

February 25, 2011
Author(s)
Pedatsur Neta, Stephen E. Stein
… relative intensities of charge states of product y- and b-ions depend on the final location of that proton. This study … distributions for dissociation of doubly charged peptide ions, using a large reference library of peptide ion fragmentation generated from ion-trap CID of peptide ions from tryptic digests. Trends in relative intensities of …

A Miniature EBIT with Ion Extraction for Isolating Highly Charged Ions

May 28, 2015
Author(s)
Shannon Hoogerheide, Joseph Tan
… development of a room-temperature miniature electron beam ion trap (EBIT) for efficient production of charge states … and electric potential necessary for the production of ions in the EBIT. In addition to radial access for in-EBIT … select a single charge state to be isolated in a secondary ion trap for further study. One goal is the production of …

Design and testing of a software feedback loop for RF power leveling

December 12, 2008
Author(s)
Xiaohai Cui, Thomas P. Crowley
… 30 ppm. In this system, a bolometric sensor with a Type IV power meter is used to detect the power. Feedback is … DC substituted power that is caused by loading of the Type IV when it is connected to the Type II. The new leveling … RF power, microwave power, bolometer, Type IV power meter …

The Mobilities of NO + (CH 3 CN)n Cluster Ions (n=0-3) Drifting in helium-Acetonitrile Mixtures

December 1, 1996
Author(s)
J A. de Gouw, L N. Ding, M Krishnamurthy, H S. Lee, E B. Anthony, V M. Bierbaum, S R. Leone
… The mobilities of NO+(CH 3 CN) n cluster ions (N=0-3) drifting in helium and in mixtures of helium and … of the geometric cross sections of the different cluster ions. The rate constants for the various cluster formation … 2 and NO + (CH 3 CN) 3 , the drift velocities for these ions are found to be strongly dependent on the acetonitrile …

Scanning Ion Microscopy with Low Energy Lithium Ions

July 1, 2014
Author(s)
Kevin A. Twedt, Lei Chen, Jabez J. McClelland
… Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers … in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential …

Mass Absorption Coefficient of Tungsten for 1600-2100 eV

February 1, 2002
Author(s)
Zachary H. Levine, S Grantham, I McNulty
… and a synchrotron source. This region includes the M IV and M V edges. The two tungsten films had thicknesses of … of tungsten, and some additional constant factors. The M V,IV edges have widths (10%-90% after backgroundsubtraction) of … M-sub-IV edge, M-sub-V edge, mass absorption coefficient, tungsten …

Mass Absorption Coefficient of Tungsten, 1600 eV to 2100 eV

January 24, 2002
Author(s)
Zachary H. Levine, S Grantham, I McNulty
… and a synchrotron source. This region includes the M IV and M V edges. The two tungsten films had thicknesses of … of tungsten, and some additional constant factors. The M V,IV edges have widths (10%-90% after backgroundsubtraction) of … M-sub-IV edge, M-sub-V edge, mass absorption coefficient, tungsten …

Mass Absorption Coefficient of Tungsten, 1606-2100 eV

January 1, 2002
Author(s)
Zachary H. Levine, S Grantham, I McNulty
… and a synchrotron source. This region includes the M IV and M V edges. The two tungsten films had thicknesses of … of tungsten, and some additional constant factors. The M V,IV edges have widths (10%-90% after backgroundsubtraction) of … M-sub-IV edge, M-sub-V edge, mass absorption coefficient, tungsten …

X-Ray Spectroscopy of Trapped Ions With a Microcalorimeter on the NIST Electron Beam Ion Trap

December 1, 2002
Author(s)
E Takacs, John D. Gillaspy, L P. Ratliff, K Makonyi, J M. Laming, E Silver, H. Schnopper, M Barbera, J. Beeman, E. E. Haller, N. Madden
… The electron beam ion trap (EBIT) was invented about 15 years ago. Judging from … and study the structure and interactions of highly charged ions. Today, EBITs exist in several different laboratories … in a variety of fields of research where multiply charged ions relevant. Recent astrophysical missions by NASA and …

Performance of a C 60 + Ion Source on a Dynamic SIMS Instrument

July 1, 2006
Author(s)
Albert J. Fahey, John G. Gillen, P Chi, Christine M. Mahoney
… An IonOptika [1] C60+ ion source has been fitted onto a CAMECA [1] ims-4f. Stable ion beams of C60+ and C602+ have been obtained with typical … able to be focussed into a spot size of ~1 ?m and scanning ion images acquired. We have performed analyses to … Buckministerfullerene, cluster ion beams, ion source, SIMS ion source …

Noninvasive monitoring of ion current and ion energy during plasma processing

July 15, 2008
Author(s)
Mark A. Sobolewski
… technique has been developed for noninvasive monitoring of ion energy and ion current in plasma reactors. The technique relies on … electrical waveforms, the technique determines the total ion current, the plasma potential and sheath voltage … ion current, ion energy, electrical measurements, inductively …

Cold atomic beam ion source for focused ion beam applications

July 23, 2013
Author(s)
Brenton J. Knuffman, Adam V. Steele, Jabez J. McClelland
… We report measurements and modeling performed on an ion source based on ionization of a laser-cooled atomic beam. … for use in next-generation, high-resolution focused ion beam (FIB) systems. Our measurements of total ion current as a function of ionization conditions support a …

Inter-ion Coulomb interactions in a Magneto-Optical Trap Ion Source

May 19, 2011
Author(s)
Jabez J. McClelland, Brenton J. Knuffman, Adam V. Steele
… We have investigated the role played by inter-ion Coulomb interactions in a magneto-optical trap ion source (MOTIS). Using a Monte Carlo simulation accounting … MOTIS, ion beams, coulomb replusion … Inter-ion Coulomb interactions in a Magneto-Optical Trap Ion Source …

Ion-Molecule Reactions and Ion Energies in CF 4 Discharges

December 1, 1999
Author(s)
B. Peko, I. V. Dyakov, R. Champion, MVVS. Rao, James K. Olthoff
… E/N values ranging from 4 x 10 -18 V m 2 (4 to 25 kTd). Ion energy and ion intensity data for the Townsend discharges are analyzed … cross sections, dissociative charge transfer, ion energies, ion molecule reactions, Townsend discharge … Ion-Molecule Reactions and Ion Energies in CF 4 Discharges …

High-brightness Cs focused ion beam from a cold-atomic-beam ion source

May 2, 2017
Author(s)
Adam V. Steele, Andrew Schwarzkopf, Jabez J. McClelland, Brenton Knuffman
… of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source … than the highest brightness observed in a Ga liquid metal ion source. The behavior of brightness as a function of beam … as next-generation circuit edit and nanoscale secondary ion mass spectrometry. …

The Discovery of Type-IV Binary Fluid Phase Behavior

October 16, 2008
Author(s)
Johanna Levelt Sengers
… mixture for constant excluded volume uncovered the Type-IV phase diagram as a transition between Type-II and Type-III … meets the common boundary of regions of Type-II and Type-IV at what Meijer coined the Van Laar point in 1989. As early … explicitly. He postulated and proved the existence of Type-IV. Aspects of his proof are discussed. …

Magneto-Optical-Trap-Based, High Brightness Ion Source for Use as a Nanoscale Probe

August 21, 2008
Author(s)
James L. Hanssen, Shannon B. Hill, Jon Orloff, Jabez J. McClelland
… on the demonstration of a low emittance, high brightness ion source based on magneto-optically trapped neutral atoms. Our source has ion optical properties comparable to or better than those of the commonly used liquid metal ion source. In addition, it has several advantages that offer …

Ion Solvation in Water Acetonitrile Mixtures

January 1, 2001
Author(s)
Raymond D. Mountain
… The results of a preliminary molecular dynamics study of ion (NA+ and Cl-) solvation and association in water, … is expected to be an important factor governing ion solvation and association. Results for ions in pure water … than the temperature in determining the degree of ion association. Preliminary results for the mixtures are …

Micro-fabricated stylus ion trap

August 7, 2013
Author(s)
Kyle S. McKay, Christian L. Arrington, Ehren D. Baca, Jonathan J. Coleman, Yves Colombe, Patrick Finnegan, Dustin A. Hite, Andrew E. Hollowell, Robert Jordens, John D. Jost, Dietrich G. Leibfried, Adam M. Rowen, Ulrich J. Warring, David J. Wineland, David P. Pappas, Andrew C. Wilson
… stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of … with the UV-LIGA technique to reduce the distance of the ion from the surface of interest. We detail the fabrication … environment. After cooling a motional mode of the ion at 4 MHz close to its ground state (n = 0.34 � 0.07), the …
Displaying 26 - 50 of 2903
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