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Declarative flow control for distributed instrumentation

Description: We have developed a 'microscopy channel' to advertise a unique set of on-line scientific instruments and to let users join a particular session, perform an experiment, collaborate with other users, and collect data for further analysis. The channel is a collaborative problem solving environment (CPSE) that allows for both synchronous and asynchronous collaboration, as well as flow control for enhanced scalability. The flow control is a declarative feature that enhances software functionality at the experimental scale. Our testbed includes several unique electron and optical microscopes with applications ranging from material science to cell biology. We have built a system that leverages current commercial CORBA services, Web Servers, and flow control specifications to meet diverse requirements for microscopy and experimental protocols. In this context, we have defined and enhanced Instrument Services (IS), Exchange Services (ES), Computational Services (CS), and Declarative Services (DS) that sit on top of CORBA and its enabling services (naming, trading, security, and notification) IS provides a layer of abstraction for controlling any type of microscope. ES provides a common set of utilities for information management and transaction. CS provides the analytical capabilities needed for online microscopy. DS provides mechanisms for flow control for improving the dynamic behavior of the system.
Date: June 1, 2001
Creator: Parvin, Bahram; Taylor, John; Fontenay, Gerald & Callahan, Daniel
Partner: UNT Libraries Government Documents Department

HIGH RESOLUTION MICROTOMOGRAPHY FOR DENSITY AND SPATIAL INFORMATION ABOUT WOOD STRUCTURES.

Description: Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the National Synchrotron Light Source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer optics developed for this application. The sample is mounted on a translation stage with which to center the sample rotation, a rotation stage to perform the rotation during data collection and a motorized goniometer head for small alignment motions. The absorption image is recorded by a single-crystal scintillator, an optical microscope and a cooled CCD array detector. Data reconstruction has provided three-dimensional geometry of the heterogeneous wood matrix in microtomographic images. Wood is a heterogeneous material composed of long lignocellulose vessels. Although wood is a strong natural product, fungi have evolved chemical systems that weaken the strength properties of wood by degrading structural vessels. Tomographic images with a resolution of three microns were obtained nonintrusively to characterize the compromised structural integrity of wood. Computational tools developed by Lindquist et al (1996) applied to characterize the microstructure of the tomographic volumes.
Date: July 22, 1999
Creator: ILLMAN,B.
Partner: UNT Libraries Government Documents Department

AUTOMATED BATCH CHARACTERIZATION OF ICF SHELLS WITH VISION-ENABLED OPTICAL MICROSCOPE SYSTEM

Description: OAK-B135 Inertial Confinement Fusion (ICF) shells are mesoscale objects with nano-scale dimensional and nano-surface finish requirements. Currently, the shell dimensions are measured by white-light interferometry and an image analysis method. These two methods complement each other and give a rather complete data set on a single shell. The process is, however, labor intensive. They have developed an automation routine to fully characterize a shell in one shot and perform unattended batch measurements. The method is useful to the ICF program both for production screening and for full characterization. It also has potential for Inertial Fusion Energy (IFE) power plant where half a million shells need to be processed daily.
Date: June 1, 2003
Creator: HUANG,H; STEPHENS,R.B; HILL,D.W; LYON,C; NIKROO,A & STEINMAN,D.A
Partner: UNT Libraries Government Documents Department

Normal-incidence multilayer mirror X-ray microscope. Final report

Description: An x-ray multilayer mirror microscope was designed constructed, and implemented to record images at a wavelength of 33.8 {Angstrom} of laser-irradiated targets. The morphology of the 33.8 {Angstrom} emission from a variety of targets was studied at the Livermore Nova laser 2-beam facility. Imaged were radiatively heated, low-density plastic and silica foams targets, x-ray laser targets, and gas-filled hohlraums. The absolute x-ray flux was determined. A two-mirror microscope and a CCD x-ray detector have been designed and constructed that will provided images with improved spatial resolution and dynamic range. The two-mirror microscope is designed to fit SIM4 on the Livermore 10-beam target chamber or any other comparably sized instrument module.
Date: November 18, 1994
Creator: Seely, J.F.
Partner: UNT Libraries Government Documents Department

Atomic force microscope: Enhanced sensitivity

Description: Atomic force microscopes (AFMs) are a recent development representing the state of the art in measuring ultrafine surface features. Applications are found in such fields of research as biology, microfabrication, material studies, and surface chemistry. Fiber-optic interferometer techniques developed at LLNL offer the potential of improving the vertical resolution of these instruments by up to 2 orders of magnitude. We are attempting to replace the current AFM measurement scheme, which consists of an optical beam deflection approach, with our fiber-optic interferometer scheme, a much more sensitive displacement measurement technique. In performing this research, we hope to accomplish two important goals; (1) to enhance the sensitivity of the AFM, and (2) to achieve important improvements in our fiber-optic interferometer technology.
Date: June 1, 1995
Creator: Davis, D.T.
Partner: UNT Libraries Government Documents Department

Frictional behavior of diamondlike carbon films in vacuum and under varying water vapor pressure.

Description: In this study, we investigated the frictional behavior of both hydrogenated and hydrogen-free diamondlike carbon (DLC) films in high vacuum (10{sup -6} Pa) at room temperature. Water was also introduced into the vacuum chamber to elucidate its effects on DLC film tribology. The hydrogen-free DLC (also referred to as tetrahedral amorphous carbon, or ta-C) was produced by an arc-PVD process, and the highly hydrogenated DLC was produced by plasma-enhanced chemical-vapor deposition. Tribological measurements of these films were made with a pin-on-disc machine with coated steel balls and coated steel discs in matched pairs under a 1 N load. The ball/disk pairs were rotated at sliding speeds in the range of 0.025-0.075 m/s. In vacuum, the steady-state friction coefficient of ta-C was of the order of 0.6 and the wear was severe, whereas for the highly hydrogenated film, friction was below 0.01, and in an optical microscope no wear could be detected. Adding water vapor to the sliding ta-C system in a vacuum chamber caused friction to decrease monotonically from 0.6 to {approx}0.05. In contrast, adding water vapor to the sliding DLC system caused the friction to increase linearly with pressure from 0.01 to 0.07. The results illustrate the importance of taking into account environmental conditions, especially the presence of water, when DLC films are being considered for a given application.
Date: March 25, 2002
Creator: Andersson, J.; Erck, R. A. & Erdemir, A.
Partner: UNT Libraries Government Documents Department

The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution and Metabolism

Description: Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for {approx}20% of global carbon fixation. We report the 34 Mbp draft nuclear genome of the marine diatom, Thalassiosira pseudonana and its 129 Kbp plastid and 44 Kbp mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, utilization of a range of nitrogenous compounds and a complete urea cycle, all attributes that allow diatoms to prosper in the marine environment. Diatoms are unicellular, photosynthetic, eukaryotic algae found throughout the world's oceans and freshwater systems. They form the base of short, energetically-efficient food webs that support large-scale coastal fisheries. Photosynthesis by marine diatoms generates as much as 40% of the 45-50 billion tonnes of organic carbon produced each year in the sea (1), and their role in global carbon cycling is predicted to be comparable to that of all terrestrial rainforests combined (2, 3). Over geological time, diatoms may have influenced global climate by changing the flux of atmospheric carbon dioxide into the oceans (4). A defining feature of diatoms is their ornately patterned silicified cell wall or frustule, which displays species-specific nano-structures of such fine detail that diatoms have long been used to test the resolution of optical microscopes. Recent attention has focused on biosynthesis of these nano-structures as a paradigm for future silica nanotechnology (5). The long history (over 180 million years) and dominance of diatoms in the oceans is reflected by their contributions to vast deposits of diatomite, most cherts and a significant fraction of current petroleum reserves (6). As photosynthetic heterokonts, diatoms reflect a fundamentally different evolutionary history from the higher plants that dominate photosynthesis ...
Date: November 14, 2005
Creator: Armbrust, E V; Berges, J A; Bowler, C; Green, B R; Martinez, D; Putnam, N H et al.
Partner: UNT Libraries Government Documents Department

Imaging of InGaN inhomogeneities using visible aperturelessnear-field scanning optical microscope

Description: The optical properties of epitaxially grown islands of InGaN are investigated with nanometer-scale spatial resolution using visible apertureless near-field scanning optical microscopy. Scattered light from the tip-sample system is modulated by cantilever oscillations and detected at the third harmonic of the oscillation frequency to distinguish the near-field signal from unwanted scattered background light. Scattered near-field measurements indicate that the as-grown InGaN islanded film may exhibit both inhomogeneous In composition and strain-induced changes that affect the optical signal at 633 nm and 532 nm. Changes are observed in the optical contrast for large 3D InGaN islands (100's of nm) of the same height. Near-field optical mapping of small grains on a finer scale reveals InGaN composition or strain-induced irregularities in features with heights of only 2 nm, which exhibit different near-field signals at 633 nm and 532 nm incident wavelengths. Optical signal contrast from topographic features as small as 30 nm is detected.
Date: June 14, 2007
Creator: Stebounova, Larissa V.; Romanyuk, Yaroslav E.; Chen, Dongxue & Leone, Stephen R.
Partner: UNT Libraries Government Documents Department

The R-curve response of ceramics with microscopic reinforcements: Reinforcement and additive effects

Description: Using direct observations with the scanning electron and optical microscopes, simultaneous measurements of fracture resistance versus crack length (R-curve behavior) and crack interactions with microstructural features at the crack tip and in its wake were made. Selecting whisker-reinforced aluminas and self-reinforced silicon nitrides, one can examine the effects of systematic modifications of microstructure and composition on the R-curve response and the mechanisms giving rise to it. Specifically, increases in whisker content and size can increase the R-Curve response, even for short crack lengths. In the self-reinforced silicon nitrides, changes in alumina: yttria additive ratios also modify the R-curve. Modeling of the R-curve response allows one to verify toughening mechanisms and, with experimental studies, to optimize the R-curve behavior in ceramics containing microscopic reinforcements, e.g., whiskers and elongated grain structures.
Date: May 1, 1996
Creator: Becher, P.F.; Sun, E.Y.; Plucknett, K,P. & Hsueh, C.H.
Partner: UNT Libraries Government Documents Department

Automated dimensional analysis using a light-sectioning microscope

Description: A computer vision system has been integrated with a modified light-sectioning microscope for quality control and inspection of a machined part whose critical dimensions are 30 to 300 {mu}m. Height measurements were determined by analysis of the projected light-section line. Transverse measurements were made using the microscope in a traditional configuration with illumination from selected elements of an external LED ring array. The light section irradiance was under computer control to accommodate the spatial variations in surface reflectance whose dynamic range exceeded that of the vision system. Part features are located by the vision system. Edges and line centers are then measured to sub-pixel resolution with a gray-level analysis algorithm. This paper describes the design and operation of this system. Details of the measurement process and analysis algorithms are provided.
Date: December 31, 1988
Creator: Loomis, J.; Lightman, A.; Poe, A. & Caldwell, R.
Partner: UNT Libraries Government Documents Department

A near-field optical microscopy nanoarray

Description: Multiplexing near-field scanning optical microscopy (NSOM) by the use of a nanoarray with parallel imaging is studied. The fabrication, characterization, and utilization of nanoarrays with {approximately} 100 nm diameter apertures spaced 500 nm center-to- center is presented. Extremely uniform nanoarrays with {approximately} 10{sup 8} apertures were fabricated by electron beam lithography and reactive ion etching. The nanoarrays were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In this paper we utilize these nanoarrays in a laser-illuminated microscope with parallel detection on a charge- coupled device (CCD). Detection of B-phycoerythrin (B-PE) molecules using near-field illumination is presented. In principle, our system can be used to obtain high lateral resolution NSOM images over a wide-field of view (e.g. 50-100 {mu}m) within seconds.
Date: December 31, 1996
Creator: Semin, D.J.; Ambrose, W.P.; Goodwin, P.M.; Kwller, A. & Wendt, J.R.
Partner: UNT Libraries Government Documents Department

Industrial applications of accelerator-based infrared sources: Analysis using infrared microspectroscopy

Description: Infrared Microspectroscopy, using a globar source, is now widely employed in the industrial environment, for the analysis of various materials. Since synchrotron radiation is a much brighter source, an enhancement of an order of magnitude in lateral resolution can be achieved. Thus, the combination of IR microspectroscopy and synchrotron radiation provides a powerful tool enabling sample regions only few microns size to be studied. This opens up the potential for analyzing small particles. Some examples for hair, bitumen and polymer are presented.
Date: September 1, 1997
Creator: Bantignies, J.L.; Fuchs, G.; Wilhelm, C.; Carr, G.L. & Dumas, P.
Partner: UNT Libraries Government Documents Department

BioSig: A bioinformatic system for studying the mechanism of intra-cell signaling

Description: Mapping inter-cell signaling pathways requires an integrated view of experimental and informatic protocols. BioSig provides the foundation of cataloging inter-cell responses as a function of particular conditioning, treatment, staining, etc. for either in vivo or in vitro experiments. This paper outlines the system architecture, a functional data model for representing experimental protocols, algorithms for image analysis, and the required statistical analysis. The architecture provides remote shared operation of an inverted optical microscope, and couples instrument operation with images acquisition and annotation. The information is stored in an object-oriented database. The algorithms extract structural information such as morphology and organization, and map it to functional information such as inter-cellular responses. An example of usage of this system is included.
Date: December 15, 2000
Creator: Parvin, B.; Cong, G.; Fontenay, G.; Taylor, J.; Henshall, R. & Barcellos-Hoff, M.H.
Partner: UNT Libraries Government Documents Department

Durable high-density data storage

Description: This paper will discuss the Focus Ion Beam (FIB) milling process, media life considerations, and methods of reading the micromilled data. The FIB process for data storage provides a new non-magnetic storage method for archiving large amounts of data. The process stores data on robust materials such as steel, silicon, and gold coated silicon. The storage process was developed to provide a method to insure the long term storage life of data. We estimate the useful life of data written on silicon or gold coated silicon to be a few thousand years. The process uses an ion beam to carve material from the surface much like stone cutting. The deeper information is carved into the media the longer the expected life of the information. The process can read information in three formats: (1) binary at densities of 3.5 Gbits/cm{sup 2}, (2) alphanumeric at optical or non-optical density, and (3) graphical at optical and non-optical density. The formats can be mixed on the same media; and thus it is possible to record, in a human readable format, instructions that can be read using an optical microscope. These instructions provide guidance on reading the higher density information.
Date: September 1, 1996
Creator: Stutz, R.A. & Lamartine, B.C.
Partner: UNT Libraries Government Documents Department

The genome of the diatom Thalassiosira pseudonana: Ecology, evolution, and metabolism

Description: Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for {approx}20% of global carbon fixation. We report the 34 Mbp draft nuclear genome of the marine diatom, Thalassiosira pseudonana and its 129 Kbp plastid and 44 Kbp mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, utilization of a range of nitrogenous compounds and a complete urea cycle, all attributes that allow diatoms to prosper in the marine environment. Diatoms are unicellular, photosynthetic, eukaryotic algae found throughout the world's oceans and freshwater systems. They form the base of short, energetically-efficient food webs that support large-scale coastal fisheries. Photosynthesis by marine diatoms generates as much as 40% of the 45-50 billion tonnes of organic carbon produced each year in the sea (1), and their role in global carbon cycling is predicted to be comparable to that of all terrestrial rainforests combined (2, 3). Over geological time, diatoms may have influenced global climate by changing the flux of atmospheric carbon dioxide into the oceans (4). A defining feature of diatoms is their ornately patterned silicified cell wall or frustule, which displays species-specific nano-structures of such fine detail that diatoms have long been used to test the resolution of optical microscopes. Recent attention has focused on biosynthesis of these nano-structures as a paradigm for future silica nanotechnology (5). The long history (over 180 million years) and dominance of diatoms in the oceans is reflected by their contributions to vast deposits of diatomite, most cherts and a significant fraction of current petroleum reserves (6). As photosynthetic heterokonts, diatoms reflect a fundamentally different evolutionary history from the higher plants that dominate photosynthesis ...
Date: September 1, 2004
Creator: Ambrust, E.V.; Berges, J.; Bowler, C.; Green, B.; Martinez, D.; Putnam, N. et al.
Partner: UNT Libraries Government Documents Department

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

Description: Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, the author introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties of suitably designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, they demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm{sup 2} for 40-{micro}m wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection. In the second part of this dissertation, the author used laser-induced native fluorescence coupled with capillary electrophoresis (LINF-CE) and microscope imaging to study the single cell degranulation. On the basis of good temporal correlation with events observed through an optical microscope, they have identified individual peaks in the fluorescence electropherograms as serotonin released from the granular core on contact with the surrounding fluid.
Date: May 25, 2001
Creator: Su, Hui
Partner: UNT Libraries Government Documents Department

Development of Nomarski microscopy for quantitative determination of surface topography

Description: The use of Nomarski differential interference contrast (DIC) microscopy has been extended to provide nondestructive, quantitative analysis of a sample's surface topography. Theoretical modeling has determined the dependence of the image intensity on the microscope's optical components, the sample's optical properties, and the sample's surface orientation relative to the microscope. Results include expressions to allow the inversion of image intensity data to determine sample surface slopes. A commercial Nomarski system has been modified and characterized to allow the evaluation of the optical model. Data have been recorded with smooth, planar samples that verify the theoretical predictions.
Date: January 1, 1979
Creator: Hartman, J. S.; Gordon, R. L. & Lessor, D. L.
Partner: UNT Libraries Government Documents Department

Nano-scale optical and electrical probes of materials and processes.

Description: This report describes the investigations and milestones of the Nano-Scale Optical and Electrical Probes of Materials and Processes Junior/Senior LDRD. The goal of this LDRD was to improve our understanding of radiative and non-radiative mechanisms at the nanometer scale with the aim of increasing LED and solar cell efficiencies. These non-radiative mechanisms were investigated using a unique combination of optical and scanning-probe microscopy methods for surface, materials, and device evaluation. For this research we utilized our new near-field scanning optical microscope (NSOM) system to aid in understanding of defect-related emission issues for GaN-based materials. We observed micrometer-scale variations in photoluminescence (PL) intensity for GaN films grown on Cantilever Epitaxy pattern substrates, with lower PL intensity observed in regions with higher dislocation densities. By adding electrical probes to the NSOM system, the photocurrent and surface morphology could be measured concurrently. Using this capability we observed reduced emission in InGaN MQW LEDs near hillock-shaped material defects. In spatially- and spectrally-resolved PL studies, the emission intensity and measured wavelength varied across the wafer, suggesting the possibility of indium segregation within the InGaN quantum wells. Blue-shifting of the InGaN MQW wavelength due to thinning of quantum wells was also observed on top of large-scale ({micro}m) defect structures in GaN. As a direct result of this program, we have expanded the awareness of our new NSOM/multifunctional SPM capability at Sandia and formed several collaborations within Sandia and with NINE Universities. Possible future investigations with these new collaborators might include GaN-based compound semiconductors for green LEDs, nanoscale materials science, and nanostructures, novel application of polymers for OLEDs, and phase imprint lithography for large area 3D nanostructures.
Date: March 1, 2007
Creator: Bogart, Katherine Huderle Andersen
Partner: UNT Libraries Government Documents Department

Report on sodium compatibility of advanced structural materials.

Description: This report provides an update on the evaluation of sodium compatibility of advanced structural materials. The report is a deliverable (level 3) in FY11 (M3A11AN04030403), under the Work Package A-11AN040304, 'Sodium Compatibility of Advanced Structural Materials' performed by Argonne National Laboratory (ANL), as part of Advanced Structural Materials Program for the Advanced Reactor Concepts. This work package supports the advanced structural materials development by providing corrosion and tensile data from the standpoint of sodium compatibility of advanced structural alloys. The scope of work involves exposure of advanced structural alloys such as G92, mod.9Cr-1Mo (G91) ferritic-martensitic steels and HT-UPS austenitic stainless steels to a flowing sodium environment with controlled impurity concentrations. The exposed specimens are analyzed for their corrosion performance, microstructural changes, and tensile behavior. Previous reports examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design, fabrication, and construction of a forced convection sodium loop for sodium compatibility studies of advanced materials. This report presents the results on corrosion performance, microstructure, and tensile properties of advanced ferritic-martensitic and austenitic alloys exposed to liquid sodium at 550 C for up to 2700 h and at 650 C for up to 5064 h in the forced convection sodium loop. The oxygen content of sodium was controlled by the cold-trapping method to achieve {approx}1 wppm oxygen level. Four alloys were examined, G92 in the normalized and tempered condition (H1 G92), G92 in the cold-rolled condition (H2 G92), G91 in the normalized and tempered condition, and hot-rolled HT-UPS. G91 was included as a reference to compare with advanced alloy, G92. It was found that all four alloys showed weight loss after sodium exposures at 550 and 650 C. The weight loss of the four alloys was comparable after sodium exposures at ...
Date: July 9, 2012
Creator: Li, M.; Natesan, K.; Momozaki, Y.; Rink, D.L.; Soppet, W.K. & Listwan, J.T. (Nuclear Engineering Division)
Partner: UNT Libraries Government Documents Department

Tomographic scanning microscope for 1-4 KeV x-rays

Description: X-ray microtomography enables three-dimensional imaging at submicron resolution with elemental and chemical state contrast. The 1-4 KeV energy region is promising for microtomography of biological, microelectronics, and materials sciences specimens. To capitalize on this potential, we are constructing a tomographic scanning x-ray microscope for 1-4 KeV x-ray on a spherical grating monochromator beamline at the Advance Photon Source. The microscope, which uses zone plate optics, has an anticipated spatial resolution of 100 nm and an energy resolution of better than 1 eV.
Date: December 31, 1995
Creator: McNulty, I.; Feng, Y.P.; Hadda, W.S. & Trebes, J.E.
Partner: UNT Libraries Government Documents Department

Ultrahigh resolution multicolor colocalization of single fluorescent nanocrystals

Description: A new method for in vitro and possibly in vivo ultrahigh-resolution colocalization and distance measurement between biomolecules is described, based on semiconductor nanocrystal probes. This ruler bridges the gap between FRET and far-field (or near-field scanning optical microscope) imaging and has a dynamic range from few nanometers to tens of micrometers. The ruler is based on a stage-scanning confocal microscope that allows the simultaneous excitation and localization of the excitation point-spread-function (PSF) of various colors nanocrystals while maintaining perfect registry between the channels. Fit of the observed diffraction and photophysics-limited images of the PSFs with a two-dimensional Gaussian allows one to determine their position with nanometer accuracy. This new high-resolution tool opens new windows in various molecular, cell biology and biotechnology applications.
Date: December 20, 2000
Creator: Michalet, X.; Lacoste, T.D.; Pinaud, F.; Chemla, D.S.; Alivisatos, A.P. & Weiss, S.
Partner: UNT Libraries Government Documents Department

Overview of the program on soft x-ray lasers and their applications at Princeton

Description: In the last several years, rapid progress in the development of soft x-ray lasers (SXL) has been observed at a number of laboratories worldwide. Although SXLs are very young'' devices they have already been used for microscopy and holography, and new ideas emerging for broader application of SXLs to microscopy, holography and lithography. This paper describes the work at Princeton University on the development of a soft x-ray imaging transmission microscopy using a SXL as a radiation source and work on the development of a novel soft x-ray reflection microscope and its application to biological cell studies and lithography. Progress in the development of a photopumped VUV laser (60 nm), and programs for the development of a small scale SXL and for the application of a powerful subpicosecond KrF laser system are also discussed. 35 refs., 9 figs., 1 tab.
Date: May 1, 1991
Creator: Suckewer, S. & Ilcisin, K. (Princeton Univ., NJ (USA). Plasma Physics Lab. Princeton Univ., NJ (USA). Dept. of Mechanical and Aerospace Engineering)
Partner: UNT Libraries Government Documents Department

[Gene sequencing by scanning molecular exciton microscopy]. Progress report, October 1, 1990--September 30, 1991

Description: This report details progress made in setting up a laboratory for optical microscopy of genes. The apparatus including a fluorescence microscope, a scanning optical microscope, various spectrometers, and supporting computers is described. Results in developing photon and exciton tips, and in preparing samples are presented. (GHH)
Date: December 31, 1991
Partner: UNT Libraries Government Documents Department

[Nanometer scale exciton spectroscopy and photochemistry: Dynamic imaging of DNA structure-activity relations and radiation signatures]. Progress report, September 24, 1990--July 24, 1991

Description: We have constructed a scanning near-field optical microscope. For this we developed subwavelength micropipette light sources containing photostable crystal tips. We have also developed a technique for pulling and metal coating for single mode optical fibers to give nanometer silica tips emitting polarized laser light. Clear images have been obtained of polymeric porous membranes with nanometer pore sizes of comparable quality to that of scanning electron microscopy, but without the need for a vacuum. This method is aimed at both transmission and fluorescence nanoscopy. We believe that at least one of these will be operational in the coming year. We have also made significant progress on the next stage: Scanning, Tunneling, Exciton Microscopy. This is based on direct energy transfer between the tip and the particular molecule or fluorophore in the sample. We expect this stage to be operational in the third year of the project. Preliminary near-field optical scans indicate our resolution is already in the nanometer range. 3 figs. (MHB)
Date: December 31, 1991
Creator: Kopelman, R.
Partner: UNT Libraries Government Documents Department