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in subjects: "Electron Microscopes"

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The microscopic world: A demonstration of electron microscopy for younger students

No Description Available.

Date: January 1, 1991

Creator: Horton, L. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Seismic isolation of an electron microscope

A unique two-stage dynamic-isolation problem is presented by the conflicting design requirements for the foundations of an electron microscope in a seismic region. Under normal operational conditions the microscope must be isolated from ambient ground noise; this creates a system extremely vulnerable to seismic ground motions. Under earthquake loading the internal equipment forces must be limited to prevent damage or collapse. An analysis of the proposed design solution is presented. This study… more

Date: January 1, 1980

Creator: Godden, W.G.; Aslam, M. & Scalise, D.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

US Atom-Resolving Microscope Project

The largest project in transmission electron microscopy in this country has recently been initiated. This project has been given the name Atomic Resolution Microscopy and its goal is to provide the instrumentation and expertise necessary to conduct materials research directly at the atomic level. Taking advantage of the best available technology in electron-optical design, its core instrumentation is a unique machine, the Atomic Resolution Microscope (ARM), which is to be built by commercial ma… more

Date: March 1, 1980

Creator: Gronsky, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

AN EVALUATION OF POTENTIAL LINER MATERIALS FOR ELIMINATING FCCI IN IRRADIATED METALLIC NUCLEAR FUEL ELEMENTS

Metallic nuclear fuels are being looked at as part of the Global Nuclear Energy Program for transmuting longlive transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products. In order to optimize the performance of these fuels, the concept of using liners to eliminate the fuel/cladding chemical interactions that can occur during irradiation of a fuel element has been investigated. The potential liner materials Zr and V have been tested using solid-solid diff… more

Date: September 1, 2007

Creator: Keiser, D. D. & Cole, J. I.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure

Laser ablation has proven to be an effective method for generating nanoparticles; particles are produced in the laser induced vapor plume during the cooling stage. To understand the in-situ condensation process, a series of time resolved light scattering images were recorded and analyzed. Significant changes in the condensation rate and the shape of the condensed aerosol plume were observed in two background gases, helium and argon. The primary particle shape and size distribution were measured… more

Date: May 31, 2007

Creator: Wen, Sy-Bor; Mao, Xianglei; Greif, Ralph & Russo, Richard E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Quantitative Microanalysis with high Spatial Resolution: Application of FEG-DTEM XEDS Microanalysis to the Characterization of Complex Microstructures in Irradiated Low Alloy Steet

To assist in the characterization of microstructural changes associated with irradiation damage in low alloy steels, the technique of quantitative x-ray mapping using a field emission gun scanning transmission electron microscope (FEG-STEM) equipped with an x-ray energy Dispersive spectrometer (XEDS) has been employed. Quantitative XEDS microanalyses of the matrix and grain boundaries of irradiated specimens have been compared with previous quantitative analyses obtained using 3D-Atom Probe Fie… more

Date: November 14, 2001

Creator: Williams, D.B., Watanabe, M. and Burke, M.G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Three-Dimensional Aberration-Corrected Scanning Transmission Electron Microscopy for Biology

Recent instrumental developments have enabled greatly improved resolution of scanning transmission electron microscopes (STEM) through aberration correction. An additional and previously unanticipated advantage of aberration correction is the greatly improved depth sensitivity that has led to the reconstruction of a three-dimensional (3D) image from a focal series. In this chapter the potential of aberration-corrected 3D STEM to provide major improvements in the imaging capabilities for biologi… more

Date: January 1, 2007

Creator: De Jonge, Niels; Sougrat, Rachid; Pennycook, Stephen J; Peckys, Diana B & Lupini, Andrew R

Item Type: Book

Partner: UNT Libraries Government Documents Department

open access

A CCD Camera with Electron Decelerator for Intermediate Voltage Electron Microscopy

Electron microscopists are increasingly turning to Intermediate Voltage Electron Microscopes (IVEMs) operating at 300 - 400 kV for a wide range of studies. They are also increasingly taking advantage of slow-scan charge coupled device (CCD) cameras, which have become widely used on electron microscopes. Under some conditions CCDs provide an improvement in data quality over photographic film, as well as the many advantages of direct digital readout. However, CCD performance is seriously degraded… more

Date: March 17, 2008

Creator: Downing, Kenneth H; Downing, Kenneth H. & Mooney, Paul E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Material Removal and Specific Energy in the Dynamic Scratching of Gamma Titanium Aluminides

Mechanical responses of three gamma titanium aluminides (TiAls) (denoted as Alloy A, Alloy B and Alloy C) subjected to dynamic scratching were studied by using a single-grit pendulum (rotating) scratch tester. The maximum depth of groove was {approx} 0.07 mm, and the scratch velocity was {approx} 1.0 m/s. Normal and tangential forces were monitored. The material removal mechanisms were examined using a scanning electron microscope (SEM) and the scratches were measured by using a laser profilome… more

Date: November 30, 2006

Creator: Wang, H.; Lin, H. T. & Wereszczak, A. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Fundamental Investigations of Nanoscale Phenomena in Beam-Assisted Nucleation, Growth and Surface Smoothing, Using in situ LEEM

The purposes for which this grant was provided were specifically (1) to construct a tandem instrument that combined a low energy electron microscope (LEEM) with an ion beam source capably of irradiating a sample during observation of the surface using LEEM; and (2) to employ the new machine to whatever degree possible to observe the evolution of clean crystal surfaces during ion beam irradiation. A principal motivation was to investigate the fundamental behavior of radiation damage under circum… more

Date: November 5, 2008

Creator: Flynn, Colin P.

Item Type: Text

Partner: UNT Libraries Government Documents Department

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STROBOSCOPIC IMAGE CAPTURE: REDUCING THE DOSE PER FRAME BY AFACTOR OF 30 DOES NOT PREVENT BEAM-INDUCED SPECIMEN MOVEMENT INPARAFFIN

Beam-induced specimen movement may be the major factor that limits the quality of high-resolution images of organic specimens. One of the possible measures to improve the situation that was proposed by Henderson and Glaeser (Henderson and Glaeser, 1985), which we refer to here as 'stroboscopic image capture', is to divide the normal exposure into many successive frames, thus reducing the amount of electron exposure--and possibly the amount of beam-induced movement--per frame. The frames would t… more

Date: August 1, 2006

Creator: Typke, Dieter; Gilpin, Christopher J.; Downing, Kenneth H. & Glaeser, Robert M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory

The last decade witnessed the rapid development and implementation of aberration correction in electron optics, realizing a more-than-70-year-old dream of aberration-free electron microscopy with a spatial resolution below one angstrom [1-9]. With sophisticated aberration correctors, modern electron microscopes now can reveal local structural information unavailable with neutrons and x-rays, such as the local arrangement of atoms, order/disorder, electronic inhomogeneity, bonding states, spin c… more

Date: April 1, 2008

Creator: Zhu, Y. & Wall, J.

Item Type: Book

Partner: UNT Libraries Government Documents Department

open access

Science & Technology Review November 2007

This month's issue has the following articles: (1) Simulating the Electromagnetic World--Commentary by Steven R. Patterson; (2) A Code to Model Electromagnetic Phenomena--EMSolve, a Livermore supercomputer code that simulates electromagnetic fields, is helping advance a wide range of research efforts; (3) Characterizing Virulent Pathogens--Livermore researchers are developing multiplexed assays for rapid detection of pathogens; (4) Imaging at the Atomic Level--A powerful new electron microscope… more

Date: October 16, 2007

Creator: Chinn, D J

Item Type: Report

Partner: UNT Libraries Government Documents Department

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An Innovative Injection and Mixing System for Diesel Fuel Reforming

This project focused on fuel stream preparation improvements prior to injection into a solid oxide fuel cell reformer. Each milestone and the results from each milestone are discussed in detail in this report. The first two milestones were the creation of a coking formation test rig and various testing performed on this rig. Initial tests indicated that three anti-carbon coatings showed improvement over an uncoated (bare metal) baseline. However, in follow-up 70 hour tests of the down selected … more

Date: December 31, 2007

Creator: Pack, Spencer

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Emergence of Strong Exchange Interaction in the Actinide Series: The Driving Force for Magnetic Stabilization of Curium

Using electron energy-loss spectroscopy in a transmission electron microscope, many-electron atomic spectral calculations and density functional theory, we examine the electronic and magnetic structure of Cm metal. We show that angular momentum coupling in the 5f states plays a decisive role in the formation of the magnetic moment. The 5f states of Cm in intermediate coupling are strongly shifted towards the LS coupling limit due to exchange interaction, unlike most actinide elements where the … more

Date: January 4, 2007

Creator: Moore, K; der Laan, G v; Haire, D; Wall, M; Schwartz, A & Soderlind, P

Item Type: Article

Partner: UNT Libraries Government Documents Department

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High-resolution mineralogical characterization and biogeochemical modeling of uranium reaction pathways at the FRC

High-Resolution Mineralogical Characterization and Biogeochemical Modeling of Uranium Reduction Pathways at the Oak Ridge Field-Research Center (FRC) Chen Zhu, Indiana University, David R. Veblen, Johns Hopkins University We have successfully completed a proof-of-concept, one-year grant on a three-year proposal from the former NABIR program, and here we seek additional two-year funding to complete and publish the research. Using a state-of-the-art 300-kV, atomic resolution, Field Emission Gun T… more

Date: June 15, 2006

Creator: Zhu, Chen

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Plasma ion sources and ion beam technology inmicrofabrications

For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB… more

Date: September 1, 2007

Creator: Ji, Lili

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Pu Workshop Letter

In preparation for the upcoming Pu Workshop in Livermore, CA, USA, during July 14 and 15, 2006, we have begun to give some thought as to how the meeting will be structured and what will be discussed. Below, you will find our first proposal as to the agenda and contents of the meeting. From you, we need your feedback and suggestions concerning the desirability of each aspect of our proposal. Hopefully, we will be able to converge to a format that is acceptable to all parties. First, it now appea… more

Date: March 6, 2006

Creator: Tobin, J G; Schwartz, A J & Fluss, M

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Markov Random Field Based Automatic Image Alignment for ElectronTomography

Cryo electron tomography (cryo-ET) is the primary method for obtaining 3D reconstructions of intact bacteria, viruses, and complex molecular machines ([7],[2]). It first flash freezes a specimen in a thin layer of ice, and then rotates the ice sheet in a transmission electron microscope (TEM) recording images of different projections through the sample. The resulting images are aligned and then back projected to form the desired 3-D model. The typical resolution of biological electron microscop… more

Date: November 30, 2007

Creator: Moussavi, Farshid; Amat, Fernando; Comolli, Luis R.; Elidan, Gal; Downing, Kenneth H. & Horowitz, Mark

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Determining the Critcial Size of EUV Mask Substrate Defects

Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by sub… more

Date: February 28, 2008

Creator: Mccall, Monnikue M.; Han, Hakseung; Cho, Wonil; Goldberg, Kenneth; Gullikson, Eric; Jeon, Chan-Uk et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Applications of Lagrangian Dispersion Modeling to the Analysis of Changes in the Specific Absorption of Elemental Carbon

We use a Lagrangian dispersion model driven by a mesoscale model with four-dimensional data assimilation to simulate the dispersion of elemental carbon (EC) over a region encompassing Mexico City and its surroundings, the study domain for the 2006 MAX-MEX experiment, which was a component of the MILAGRO campaign. The results are used to identify periods when biomass burning was likely to have had a significant impact on the concentrations of elemental carbon at two sites, T1 and T2, downwind of… more

Date: March 7, 2008

Creator: Doran, J. C.; Fast, Jerome D.; Barnard, James C.; Laskin, Alexander; Desyaterik, Yury; Gilles, Marry K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

In-situ Studies of the Martensitic Transformation in Ti Thin Films using the Dynamic Transmission Microscope (DTEM)

The {alpha} to {beta} transition in pure Ti occurs mainly by a 'martensitic type' phase transformation. In such transformations, growth rates and interface velocities tend to be very large, on the order of 10{sup 3} m/s, making it difficult to observe the transformation experimentally. With thin films, it becomes even more difficult to observe, since the large surface augments the nucleation and transformation rates to levels that require nanosecond temporal resolution for experimental observat… more

Date: November 21, 2005

Creator: LaGrange, T. B.; Campbell, G. H.; Colvin, J. D.; King, W. E.; Browning, N. D.; Armstrong, M. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electron transport through single carbon nanotubes

We report on the transport of energetic electrons through single, well aligned multi-wall carbon nanotubes (CNT). Embedding of CNTs in a protective carbon fiber coating enables the application of focused ion beam based sample preparation techniques for the non-destructive isolation and alignment of individual tubes. Aligned tubes with lengths of 0.7 to 3 mu m allow transport of 300 keV electrons in a transmission electron microscope through their hollow cores at zero degree incident angles and … more

Date: August 1, 2007

Creator: Schenkel, Thomas; Chai, G.; Heinrich, H.; Chow, L. & Schenkel, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

DESIGN OF A MICROFABRICATED, TWO-ELECTRODE PHASE-CONTRAST ELEMENTSUITABLE FOR ELECTRON MICROSCOPY

A miniature electrostatic element has been designed to selectively apply a ninety-degree phase shift to the unscattered beam in the back focal plane of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. The design involves a cylindrically shaped, biased-voltage electrode, which is surrounded by a concentric grounded electrode. Electrostatic calculations have been used to determine that the fringing fields in the region of the scattered elect… more

Date: September 20, 2006

Creator: Cambie, Rossana; Downing, Kenneth H.; Typke, Dieter; Glaeser,Robert M. & Jin, Jian

Item Type: Article

Partner: UNT Libraries Government Documents Department