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Resistance behavior of Cr-Si-O thin films (open access)

Resistance behavior of Cr-Si-O thin films

Thin coatings of Cr-Si-O are assessed for use as a resistor. The submicron thick films are sputter deposited using a (l-x)Ar-(x)O{sub 2} working gas. Several compacts of metal and oxide powders are commercially prepared for use as the sputter targets. The deposition process yields film compositions which range from 2 to 30 at.% Cr and 20 to 45 at.% Si as measured using Rutherford backscattering. A broad range of resistivities from 10{sup 1} to 10{sup 14}{Omega} cm are found as measured through the film thickness between metal pads deposited onto the Cr-Si-O surface. The film structure and morphology are characterized using transmission electron microscopy from which the resistance behavior can be correlated to the distribution of metallic particles. Thermal aging reveals the metastability of the Cr- Si-O film morphology and resistance behavior.
Date: October 23, 1996
Creator: Jankowski, Alan Frederic; Hayes, Jeffrey P.; Musket, R.; Cosandey, F.; Gorla, Chandrasekhar E.; Besser, Ronald S. et al.
System: The UNT Digital Library
Simple numerical models for antiproton-hydrogen scattering (open access)

Simple numerical models for antiproton-hydrogen scattering

A diode-side-pumped discrete-optic E{sup 3+}:YAG laser employs pump-light coupling through a sapphire plate diffusion-bonded to the laser slab, giving reduced thermal lensing and exceptional beam quality (M{sup 2} {approx} 1.3.) The novel architecture is also applicable to other side-pumped lasers.
Date: August 23, 1996
Creator: Morgan Jr., D. L., LLNL
System: The UNT Digital Library
Updated measurement of the tau lifetime at SLD (open access)

Updated measurement of the tau lifetime at SLD

We present an updated measurement of the tau lifetime at SLD. 4316 {tau}-pair events, selected from a 150k Z{sup 0} data sample, are analyzed using three techniques: decay length, impact parameter, and impact parameter difference methods. The measurement benefits from the small and stable interaction region at the SLC and the precision CCD pixel vertex detector of the SLD. The combined result is: {tau}{sub {tau}} = 288.1 {+-} 6.1(stat) {+-} 3.3(syst) fs.
Date: July 23, 1996
Creator: unknown
System: The UNT Digital Library
High definition ultrasound imaging for battlefield medical applications (open access)

High definition ultrasound imaging for battlefield medical applications

A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.
Date: June 23, 1996
Creator: Kwok, K. S.; Morimoto, A. K.; Kozlowski, D. M.; Krumm, J. C.; Dickey, F. M.; Rogers, B. et al.
System: The UNT Digital Library
Introduction to Python (open access)

Introduction to Python

This report contains viewgraphs on a object-oriented programming language called Python. The basic elements of Python and its new numerical extension are discussed.
Date: May 23, 1996
Creator: Dubois, P.F.
System: The UNT Digital Library
A review of ELMs in divertor tokamaks (open access)

A review of ELMs in divertor tokamaks

This paper reviews what is known about edge localized modes (ELMs), with an emphasis on their effect on the scrape-off layer and divertor plasmas. ELM effects have been measured in the ASDEX-U, C-Mod, COMPASS-D, DIII-D, JET, JFT-2M,JT-60U, and TCV tokamaks and are reported here. At least three types of ELMs have been identified and their salient features determined. Type-1 giant ELMs can cause the sudden loss of up to 10-15% of the plasma stored energy but their amplitude ({Delta}W/W) does not increase with increasing power. Type- 3 ELMs are observed near the H-mode power threshold and produce small energy dumps (1-3% of the stored energy). All ELMs increase the scrape- off layer plasma and produce particle fluxes on the divertor targets which are as much as ten times larger that the quiescent phase between ELMs. The divertor heat pulse is largest on the inner target, unlike that of L-Mode or quiescent H-mode; some tokamaks report radial structure in the heat flux profile which is suggestive of islands or helical structures. The power scaling of Type-1 ELM amplitude and frequency have been measured in several tokamaks and has recently been applied to predictions of the ELM Size in ITER. Concern over …
Date: May 23, 1996
Creator: Hill, D.N.
System: The UNT Digital Library
Safety overview of the National Ignition Facility (open access)

Safety overview of the National Ignition Facility

The National Ignition Facility (NIF) is a proposed US Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 laser beams onto a tiny deuterium- tritium target located at the center of a spherical target chamber. The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons physics, provide an above ground simulation capability for nuclear weapons effects testing, and contribute to the development of inertial fusion for electrical power production. The NIF has been classified as a radiological, low hazard facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A draft Preliminary Safety Analysis Report (PSAR) has been written, and this will be finalized later in 1996. This paper summarizes the safety issues associated with the operation of the NIF. It provides an overview of the hazards, estimates maximum routine …
Date: May 23, 1996
Creator: Brereton, S.J.; McLouth, L.; Odell, B.; Singh, M.; Tobin, M. & Trent, M.
System: The UNT Digital Library
Performance measurements of sealed-tube electron beam windows (open access)

Performance measurements of sealed-tube electron beam windows

This paper describes the performance of the thin-film windows used in a new sealed-tube electron gun. Measurements include beam current, power, and power density along with window transmission, temperature, electron scattering and window life tests. A number of novel beam diagnostic tools were developed as part of this effort. Results are compared to Monte Carlo computer predictions and show good agreement. Transmitted beam powers in excess of 200 watts have been achieved, with current densities exceeding 30 milliamperes per square centimeter at sixty kilovolts beam energy. Predicted window wearout time exceeds several thousand hours at a current density of two milliamperes per square centimeter and a beam accelerating voltage of 60 kilovolts. This work was carried out under a Cooperative Research and Development Agreement (CRADA) between Lawrence Livermore National Laboratory and American International Technologies, Inc.
Date: February 23, 1996
Creator: Myers, B. R.; Chen, H. L.; Meyer, G. & Wakalopulos, G.
System: The UNT Digital Library