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Optimization of Micromachined Photon Devices

Description: The Oak Ridge National Laboratory has been instrumental in developing ultraprecision technologies for the fabrication of optical devices. We are currently extending our ultraprecision capabilities to the design, fabrication, and testing of micro-optics and MEMS devices. Techniques have been developed in our lab for fabricating micro-devices using single point diamond turning and ion milling. The devices we fabricated can be used in micro-scale interferometry, micro-positioners, micro-mirrors, a… more
Date: July 18, 1999
Creator: Datskos, P. G.; Datskou, I.; Evans, B. M., III & Rajic, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Position Sensitive Scintillation Neutron Detectors Using a Crossed-Fiber Optic Readout Array

Description: The Spallation Neutron Source (SNS) under construction at the Oak Ridge National Laboratory will be the most important new neutron scattering facility in the United States. Neutron scattering instruments for the SNS will require large area detectors with fast response (< 1 microsecond), high efficiency over a wide range of neutron energies (0.1 to 10 eV), and low gamma ray sensitivity. We are currently developing area neutron detectors based on a combination of 6 LiF/ZnS scintillator screens co… more
Date: July 18, 1999
Creator: Holcomb, David E.; Hutchinson, Donald P.; Ramsey, James A. & Richards, Roger K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A future vision of nuclear material information systems

Description: To address the current and future needs for nuclear materials management and safeguards information, Lawrence Livermore National Laboratory envisions an integrated nuclear information system that will support several functions. The vision is to link distributed information systems via a common communications infrastructure designed to address the information interdependencies between two major elements: Domestic, with information about specific nuclear materials and their properties, and Intern… more
Date: July 18, 1999
Creator: Suski, N. & Wimple, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Improved CO [lidar detector]

Description: A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short … more
Date: July 18, 1999
Creator: Jacobson, Phillip L.; Busch, George E.; Thompson, David C.; Remelius, Dennis K. & Wells, F. David
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High Performance Signal and Image Processing for Remote Sensing Using Reconfigurable Computers

Description: It is not uncommon for remote sensing systems to produce in excess of 100 Mbytes/sec. Los Alamos National Laboratory designed a reconfigurable computer to tackle the signal and image processing challenges of high bandwidth sensors. Reconfigurable computing, based on field programmable gate arrays, offers ten to one hundred times the performance of traditional microprocessors for certain algorithms. This paper discusses the architecture of the computer and the source of performance gains, as wel… more
Date: July 18, 1999
Creator: Caffrey, M.; Szymanski, J.J.; Begtrup, A.; Layne, J.; Nelson, T.; Robinson, S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Recent Developments in Electronic Radiography

Description: An overview of the radiographic capabilities with emphasis on electronic image detection and processing at the Los Alamos National Laboratory is presented. Fixed facilities and portable x-ray sources and imaging systems make up the Los Alamos capability. Examples of imaging with large area amorphous silicon imaging panels, a portable computed tomography system, high speed x-ray imaging applications and equipment, and small area, high resolution imagers are given. Radiographic simulation and rev… more
Date: July 18, 1999
Creator: Fry, D. A.; Claytor, T. N.; Davis, A. W.; Jones, M. H.; Sheats, M. J.; Stupin, D. M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Wave Speeds, Riemann Solvers and Artificial Viscosity

Description: A common perspective on the numerical solution of the equation Euler equations for shock physics is examined. The common viewpoint is based upon the selection of nonlinear wavespeeds upon which the dissipation (implicit or explicit) is founded. This perspective shows commonality between Riemann solver based method (i.e. Godunov-type) and artificial viscosity (i.e. von Neumann-Richtmyer). As an example we derive an improved nonlinear viscous stabilization of a Richtmyer-Lax-Wendroff method. Addi… more
Date: July 18, 1999
Creator: Rider, W. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

11th International Conference of Radiation Research

Description: Topics discussed in the conference included the following: Radiation Physics, Radiation Chemistry and modelling--Radiation physics and dosimetry; Electron transfer in biological media; Radiation chemistry; Biophysical and biochemical modelling; Mechanisms of DNA damage; Assays of DNA damage; Energy deposition in micro volumes; Photo-effects; Special techniques and technologies; Oxidative damage. Molecular and cellular effects-- Photobiology; Cell cycle effects; DNA damage: Strand breaks; DNA da… more
Date: July 18, 1999
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Huygens-Fresnel Wave-Optics Simulation of Atmospheric Optical Turbulence and Reflective Speckle in CO

Description: The measurement sensitivity of CO{sub 2} differential absorption LIDAR (DIAL) can be affected by a number of different processes. Two of these processes are atmospheric optical turbulence and reflective speckle. Atmospheric optical turbulence affects the beam distribution of energy and phase on target. The effects of this phenomenon include beam spreading, beam wander and scintillation which can result in increased shot-to-shot signal noise. In addition, reflective speckle alone has been shown … more
Date: July 18, 1999
Creator: Nelson, D. H.; Petrin, R. R.; Quick, C. R.; Jolin, L. J.; MacKerrow, E. P.; Schmidtt, M. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Calibration Procedures for a Two-Modulator Generalized Ellipsometer

Description: A Two-Modulator Generalized Ellipsometer (2-MGE) has been extremely useful in characterizing optical properties of uniaxial bulk materials, thin films and diffraction gratings. The instrument consists of two polarizer-photoelastic modulator pairs, one operating as the polarization state generator and the other as the polarization state detector. Each photoelastic modulator operates at a different remnant frequency (such as 50 kHz and 60 kHz), making it possible to measure eight elements of the … more
Date: July 18, 1999
Creator: Chen, C.; Jellison, G. E., Jr. & Modine, F.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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