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Search Publications by: Jabez J McClelland (Fed)

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Displaying 26 - 50 of 137

Giant surface conductivity enhancement in a carbon nanotube composite by ultraviolet light exposure

July 29, 2016
Author(s)
Christian J. Long, Nathan D. Orloff, Kevin A. Twedt, Thomas F. Lam, Luis Fernando Vargas Lara, Minhua Zhao, Bharath NMN Natarajan, Keana C. Scott, Eric Marksz, Tinh Nguyen, Jack F. Douglas, Jabez J. McClelland, Edward J. Garboczi, Jan Obrzut, James A. Liddle
Carbon nanotube composites are lightweight, multifunctional materials with readily adjustable mechanical and electrical properties—relevant to the aerospace, automotive, and sporting goods industries as high-performance building materials. Here, we combine

Cure temperature influences electrical properties via carbon nanotube-rich domain formation

July 27, 2016
Author(s)
Chelsea S. Davis, Nathan D. Orloff, Jeremiah W. Woodcock, Christian J. Long, Kevin A. Twedt, Bharath NMN Natarajan, Jonathan E. Seppala, Jabez J. McClelland, Jan Obrzut, James A. Liddle, Jeffrey W. Gilman
Carbon nanotube (CNT) nanocomposites are enticing materials that enable engineers to tailor structural and electrical properties for applications in the automotive and aerospace industries. CNT mass fraction and the matrix cure temperature are two ways to

Bright focused ion beam sources based on laser-cooled atoms

March 24, 2016
Author(s)
Jabez J. McClelland, Adam V. Steele, Brenton J. Knuffman, Kevin A. Twedt, Andrew D. Schwarzkopf, Truman M. Wilson
Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a

Imaging Nanophotonic Modes of Microresonators using a Focused Ion Beam

January 15, 2016
Author(s)
Kevin A. Twedt, Jie J. Zou, Marcelo I. Davanco, Kartik A. Srinivasan, Jabez J. McClelland, Vladimir A. Aksyuk
Optical microresonators have proven powerful in a wide range of applications, including cavity quantum electrodynamics, biosensing, microfludics, and cavity optomechanics. Their performance depends critically on the exact distribution of optical energy

New Ion Source for High Precision FIB Nanomachining and Circuit Edit

December 31, 2014
Author(s)
Adam V. Steele, Brenton Knuffman, Jabez J. McClelland
We present a review of the Low Temperature Ion Source (LoTIS): its aims, design, performance data collected to date, and focused spot size projections when integrated with a FIB. LoTIS provides a Cs+ beam that has been measured to have high brightness (>

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 and beam energies from 500 eV to 5 keV. These beam energies are much lower than the typical

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. We show a high brightness and a low energy spread, suitable for use in next-generation, high-resolution focused ion beam (FIB) systems. Our

Nanoscale Focused Ion Beam from Laser-cooled Lithium Atoms

October 26, 2011
Author(s)
Brenton J. Knuffman, Adam V. Steele, Jon Orloff, Jabez J. McClelland
To advance the capabilities of focused ion beam (FIB) technology, we have created a low-energy FIB from photoionized lithium atoms collected in a magneto-optical trap (MOT). This magneto-optical trap ion source relies on both the low temperature of the

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 for all pair-wise ion-ion Coulomb interactions in the source, we have calculated the broadening

Electron Vortex Beams with High Quanta of Orbital Angular Momentum

January 14, 2011
Author(s)
Benjamin James McMorran, Amit K. Agrawal, Ian M. Anderson, Andrew A. Herzing, Henri J. Lezec, Jabez J. McClelland, John Unguris
Analogous to vortices in light optical beams, electron optical beams with helical wavefronts carry orbital angular momentum and promise new capabilities for electron microscopy and other applications. We use nanofabricated diffraction holograms in an

A Focused Chromium Ion Beam

October 21, 2010
Author(s)
Adam V. Steele, Brenton J. Knuffman, Jabez J. McClelland, Jon Orloff
With the goal of expanding the capabilities of focused ion beam microscopy and milling systems, we have demonstrated nanoscale focusing of chromium ions produced in a magneto-optical trap ion source (MOTIS). Neutral chromium atoms are captured into a

Theoretical model of errors in micromirror-based three-dimensional particle tracking

June 1, 2010
Author(s)
Andrew J. Berglund, Matthew D. McMahon, Jabez J. McClelland, James A. Liddle
Several recently developed particle-tracking and imaging methods have achieved three-dimensional sensitivity through the introduction of angled micromirrors into the observation volume of an optical microscope. We model the imaging response of such devices

Imaging Response of Optical Microscopes Containing Angled Micromirrors

April 30, 2009
Author(s)
Andrew J. Berglund, Matthew D. McMahon, Jabez J. McClelland, James A. Liddle
We describe the aberrations induced by introducing micromirrors into the object space of a microscope. These play a critical role in determining the accuracy of recent three-dimensional particle tracking methods based on such devices.

3D Particle Trajectories Observed by Orthogonal Tracking Microscopy

February 9, 2009
Author(s)
Matthew D. McMahon, Andrew J. Berglund, Peter T. Carmichael, Jabez J. McClelland, James A. Liddle
We demonstrate high-resolution, high-speed 3D nanoparticle tracking using angled micromirrors. When angled micromirrors are introduced into the field of view of an optical microscope, reflected side-on views of a diffusing nanoparticle are projected

Fast, bias-free algorithm for tracking single particles with variable size and shape

August 26, 2008
Author(s)
Andrew J. Berglund, Matthew D. McMahon, Jabez J. McClelland, James A. Liddle
We introduce a fast and robust technique for single-particle tracking with nanometer accuracy.We extract the center-of-mass of the image of a single particle with a simple, iterative algorithm that efficiently suppresses background-induced bias in a

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
We report 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

Narrow-Line Magneto-Optical Cooling and Trapping of Strongly Magnetic Atoms

March 21, 2008
Author(s)
Andrew J. Berglund, James L. Hanssen, Jabez J. McClelland
We trap and cool erbium atoms in a quadrupole magnetic field using a stabilized laser tuned to the blue side of a narrow (8 kHz) atomic resonance. Cooling and trapping are observed with a single incident beam, as well as with multiple beams. The trap forms

Sub-Doppler Laser Cooling and Magnetic Trapping of Erbium

November 27, 2007
Author(s)
Andrew J. Berglund, Simone Lee, Jabez J. McClelland
We investigate cooling mechanisms in magneto-optically and magnetically trapped erbium. We find efficient sub-Doppler cooling in our trap, which can persist even in large magnetic fields due to the near degeneracy of two Lande g factors. Furthermore, a

Laser Cooled Atoms as a Focused Ion Beam Source

December 21, 2006
Author(s)
James L. Hanssen, Jabez J. McClelland, E Dakin, M Jacka
The evolving field of nanofabrication demands that more precise fabrication and evaluation tools be developed. We describe a method for creating a high quality focused ion beam with enhanced capabilities using an ion source based on laser-cooled neutral

Using Laser-Cooled Atoms as a Focused Ion Beam Source

December 1, 2006
Author(s)
James L. Hanssen, E Dakin, Jabez J. McClelland, M Jacka
The authors describe a new method for creating a high quality focused ion beam using laser-cooled neutral atoms in a magneto-optical trap as an ion source. They show that this new technique can provide spot resolutions and brightness values that are better

Natural Linewidth of the 401-nm Laser-Cooling Transition in Er I

June 20, 2006
Author(s)
Jabez J. McClelland
A measurement of the natural linewidth of the 401 nm 4f 126s 2 ( 3H 6) {rarr} 4f 12( 3H)6s6p ( 1P o 1) (6,1) 7 o transition in Er I is presented. Using laser-induced fluorescence in an atomic beam, a linewidth of (36.0 {plus or minus} 1.2) MHz is observed

Laser Cooling Without Repumping: A Magneto-Optical Trap for Erbium Atoms

April 14, 2006
Author(s)
Jabez J. McClelland, James L. Hanssen
We report on a novel mechanism that allows for laser cooling of atoms that do not have a closed cycling transition. This mechanism is observed in a magneto-optical trap for erbium, an atom with a very complex energy level structure with multiple pathways

Laser Cooling of Erbium Atoms

May 21, 2005
Author(s)
Jabez J. McClelland, H Y. Ban, Marcus Jacka, James L. Hanssen, Joseph Reader
We have identified five closed, or nearly-closed, J ? J + 1 transitions in atomic erbium at wavelengths of 401 nm, 583 nm, 631 nm, 841 nm, and 1299 nm. These transitions can be reached by common tunable single-frequency laser systems, and are thus in

Laser Cooling Transitions in Atomic Erbium

April 18, 2005
Author(s)
H Ban, M Jacka, James L. Hanssen, Joseph Reader, Jabez J. McClelland
We discuss laser cooling opportunities in atomic erbium, identifying five J rarr} J + 1 transitions from the 4f 126s 2 3H 6 ground state that are accessible to common visible and near-infrared continuous-wave tunable lasers. We present lifetime