View the LLNL home Back to the S&TR home Subscribe to Our magazine Send 
us your comments Browse through our index






Privacy &
Legal Notice

September 2002

The Laboratory
in the News

Commentary by
Michael R. Anastasio

A Hitchhiker's Guide to Early Earth

A New World of Maps

Solid-Oxide Fuel Cells Stack Up to Efficient, Clean Power

Empowering Light—Historic Accomplishments in Laser Research





Matthew Everett, Billy W. Colston, Luiz B. Da Silva, Dennis Matthews
Catheter Guided by Optical Coherence Domain Refectometry
U.S. Patent 6,384,915 B1
May 7, 2002
A guidance and viewing system based on multiplexed optical coherence domain reflectometry is incorporated into a catheter, endoscope, or other medical device to measure at discrete points on the device the location, thickness, and structure of the arterial walls or other intracavity regions during minimally invasive medical procedures. The information will be used both to guide the device through the body and to evaluate the tissue through which the device is being passed. Multiple optical fibers are situated along the circumference of the device. Light from the distal end of each fiber is directed onto the interior cavity walls via small-diameter optics such as gradient index lenses and mirrored corner cubes. Both forward-viewing and side-viewing fibers can be included. The light reflected or scattered from the cavity walls is then collected by the fibers and multiplexed at the proximal end to the sample arm of an optical low-coherence reflectometer. The system may also be implemented in a nonmedical inspection device.

C. Brent Dane, Lloyd A. Hackel
Coherent Beam Combiner for a High Power Laser
U.S. Patent 6,385,228 B1
May 7, 2002
A phase-conjugate laser mirror using Brillouin-enhanced four-wave mixing allows multiple independent laser apertures to be phase locked, producing an array of diffraction-limited beams with no piston-phase errors. The beam combiner has application in laser and optical systems requiring high average power, high pulse energy, and low beam divergence. A broad range of applications exists in laser systems for industrial processing, especially in the field of metal surface treatment and laser shot peening.

Matthew J. Everett, Joseph G. Davis
Birefringence Insensitive Optical Coherence Domain Reflectometry System
U.S. Patent 6,385,358 B1
May 7, 2002
An insensitive fiber-optic optical coherence domain reflectometry (OCDR) system containing nonpolarization maintaining (non-PM) fiber in the sample arm and the reference arm without suffering from signal degradation caused by birefringence. The use of non-PM fiber significantly reduces the cost of the OCDR system and provides a disposable or multiplexed section of the sample arm. The dispersion in the reference arm and sample arm of the OCDR system is matched to achieve high-resolution imaging. This system is useful in medical applications or for nonmedical in situ probes. The disposable section of non-PM fiber in the sample arm can be conveniently replaced when contaminated by a sample or a patient.

Ronald N. Leif, Kevin G. Knauss, Robin L. Newmark, Roger D. Aines, Craig Eaker
Increasing Subterranean Mobilization of Organic Contaminants and Petroleum by Aqueous Thermal Oxidation
U.S. Patent 6,387,278 B1
May 14, 2002
In situ hydrous pyrolysis–partial oxidation of organics at the site of the organics constrained in a subsurface reservoir produces surfactants that can form an oil–water emulsion, which can be effectively removed from an underground formation. The removal of the oil–water emulsions is particularly useful in several applications, for example, soil contaminant remediation and enhanced oil recovery operations. A portion of the constrained organics reacts in heated reservoir water with injected steam containing dissolved oxygen gas at ambient reservoir conditions to produce such surfactants.

Richard F. Post
Electromechanical Battery Design Suitable for Back-up Power Applications
U.S. Patent 6,396,186 B1
May 28, 2002
The windings that couple energy into and out of the rotor of an electromechanical battery are modified. The normal stator windings of the generator–motor have been replaced by two orthogonal sets of windings. Because of their orthogonality, the windings are decoupled from each other electrically, although each can receive or deliver power flows from the rotating field produced by the array of permanent magnets. Because of the orthogonal design of the stator windings and the high mechanical inertia of the flywheel rotor, the resulting power delivered to the computer system is completely insensitive to any and all electrical transients and variabilities from the main power source. This includes insensitivity to complete failure for a period determined only by the amount of stored kinetic energy in the electromechanical battery modules. Furthermore, there is no need for fast-acting, fractional-cycle switches, such as those used in conventional systems, which are difficult to implement.

Henry N. Chapman, Keith A. Nugent
Condenser for Ring-Field Deep Ultraviolet and Extreme Ultraviolet Lithography
U.S. Patent 6,398,374 B1
June 4, 2002
A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror that is illuminated by a collimated or converging beam at gazing incidence. The ripple plate comprises a flat or curved plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

Werner Bergman
Low Pressure Drop, Multi-Slit Vertical Impactor
U.S. Patent 6,402,817 B1
June 11, 2002
Fluid flow is directed to a multiplicity of slit nozzles positioned so that the fluid flow is directed into a gap between the nozzles and to a number of receiving chambers and a number of exhaust chambers. The nozzles and chambers are selected so that the fluid flow will be separated into a first-particle-flow component with larger particles and a second-particle-flow component with the smaller particles.

Paul G. Carey, Jesse B. Thompson, Nicolas J. Colella, Kenneth A. Williams
Process for Electrically Interconnecting Electrodes
U.S. Patent 6,402,881 B1
June 11, 2002
Electrical interconnects for solar cells or other electronic components using a silver–silicone paste or a lead–tin no-clean fluxless solder cream, whereby the high breakage of thin (less than 6-mil-thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention use copper strips that are secured to the solar cells by a silver–silicon conductive paste that can be used at room temperature or by a lead–tin solder cream that eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high-current testing and that the interconnects provided a low contact resistance value.

Theodore F. Baumann, John G. Reynolds, Glenn A. Fox
Thiacrown Polymers for Removal of Mercury from
Waste Streams

U.S. Patent 6,402,960 B1
June 11, 2002
Thiacrown polymers immobilized to a polystyrene-divinylbenzene matrix react with mercury ions (Hg2+) under a variety of conditions to efficiently and selectively remove Hg2+ from acidic aqueous solutions, even in the presence of a variety of other metal ions. The mercury can be recovered and the polymer regenerated. This mercury removal method has utility in the treatment of industrial wastewater, where a selective and cost-effective removal process is required.

Herbert W. Friedman, Terry J. Porter
System for Beaming Power from Earth to a High Altitude Platform
U.S. Patent 6,407,535 B1
June 18, 2002
Power is transmitted to a high-altitude platform by an array of diode-pumped solid-state lasers, each operated at a single range of laser wavelength outside of infrared and without using adaptive optics. Each laser produces a beam with a desired arrival spot size. An aircraft avoidance system uses a radar system for automatic control of the shutters of the laser.

Richard C. Montesanti, Stanley F. Locke, Samuel L. Thompson
Ultra-Precision Positioning Assembly
U.S. Patent 6,408,526 B1
June 25, 2002
An apparatus and method for ultraprecision positioning. A slide base provides a foundation to support the apparatus. A slide plate moves with respect to the slide base along a first geometric axis. Either a ball screw or a piezoelectric actuator working separately or in conjunction displaces the slide plate with respect to the slide base along the first geometric axis. A linking device directs a primary force vector into a centerline of the ball screw. The linking device consists of a first link that directs a first portion of the primary force vector to an apex point located along the centerline of the ball screw and a second link for directing a second portion of the primary force vector to the apex point. A set of rails, oriented substantially parallel to the centerline of the ball screw, directs movement of the slide plate with respect to the slide base along the first geometric axis and is positioned such that the apex point falls within a geometric plane formed by the rails. The slide base, the slide plate, the ball screw, and the linking device together form a slide assembly. Multiple slide assemblies can be distributed about a platform. In such a configuration, the platform may be raised and lowered or tipped and tilted by jointly or independently displacing the slide plates.

Lloyd Hackel, Fritz Harris
Contour Forming of Metals by Laser Peening
U.S. Patent 6,410,884 B1
June 25, 2002
A method and apparatus for forming shapes and contours in metal sections by generating laser-induced compressive stress on the surface of the metal work piece. The laser process can generate deep compressive stress to shape even thick components without inducing unwanted tensile stress at the metal surface. The precision of the laser-induced stress enables exact prediction and subsequent contouring of parts. A light beam of 10 to 100 joules per pulse is imaged to create an energy fluence of 60 to 200 joules per square centimeter on an absorptive layer applied over a metal surface. A tamping layer of water is flowed over the absorptive layer. The absorption of laser light causes a plasma to form and consequently creates a shock wave that induces a deep residual compressive stress into the metal. The metal responds to this residual stress by bending.



Go to the Awards page



Back | S&TR Home | LLNL Home | Help | Phone Book | Comments
Site designed and maintained by Kitty Tinsley

Lawrence Livermore National Laboratory
Operated by the University of California for the U.S. Department of Energy

UCRL-52000-02-9 | October 7, 2002