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March 2001

The Laboratory in
the News

Commentary by Michael Anastasio

in the Superblock

Computer Simulation Workshop

Research with TEM

Laser Peening




Joe N. Lucas
Method for Isolating Chromosomal DNA in Preparation for Hybridization in Suspension
U.S. Patent 6,077,671 June 20, 2000
A method is provided for detecting nucleic acid sequence aberrations using two immobilization steps. A nucleic acid sequence aberration is present when one acid sequence has both a first nucleic acid sequence type (for example, from a first chromosome) and a second nucleic acid sequence type (for example, from a second chromosome). In the method, immobilization of a first hybridization probe is used to isolate a first set of nucleic acids from a sample of the first nucleic acid sequence type. Immobilization of a second hybridization probe is then used to detect and isolate a second set of nucleic acids from within the first set. The presence of the second set of nucleic acids indicates the presence of a nucleic acid sequence aberration. Chromosomal DNA in a sample containing cell debris is prepared for hybridization in suspension by treating the mixture with RNase. The treated DNA can also be fixed prior to hybridization.

Charles G. Stevens and Norman L. Thomas
Immersion Echelle Spectrograph
U.S. Patent 6,078,048 June 20, 2000
A small spectrograph containing no moving components and capable of providing high-resolution spectra of the mid-infrared region from 2 to 4 micrometers in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 0.00005 square centimeters per steradian. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first-order transmission grating in a cross-dispersing configuration to provide a two-dimensional spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a nearly aberration-free axially symmetric design. The spectrometer has potential uses in general research as well as in areas such as monitoring atmospheric constituents for air quality, climate change and global warming research, and monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

Alan D. Conder
Vacuum-Compatible Miniature CCD Camera Head
U.S. Patent 6,078,359 June 20, 2000
A charge-coupled device (CCD) camera head that can replace film for digital imaging of visible light, ultraviolet radiation, and soft-to-penetrating x rays, such as within a target chamber where laser-produced plasmas are studied. The camera head is small, is capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, allowing for close (0.22 centimeters, for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high-energy-density plasmas in a variety of military, industrial, and medical imaging applications.

Jesse D. Wolfe and Norman L. Thomas
Durable Silver Coating for Mirrors
U.S. Patent 6,078,425 June 20, 2000
A durable multilayer mirror that includes reflective layers of aluminum and silver and has high reflectance over a broad spectral range, from ultraviolet to visible to infrared. An adhesion layer of a nickel and/or chromium alloy or nitride is deposited on an aluminum surface, and a thin layer of silver is then deposited on the adhesion layer. The silver layer is protected by a passivation layer of a nickel and/or chromium alloy or nitride and by one or more durability layers made of metal oxides and typically a first layer of metal nitride. The durability layers may include a composite silicon aluminum nitride and an oxinitride transition layer to improve bonding between nitride and oxide layers.

Joe N. Lucas
Method for Obtaining Chromosome Painting Probes
U.S. Patent 6,132,974 October 17, 2000
A method for determining a clastogenic signature of a sample of chromosomes. The frequency of each of two types of chromosome aberration present in the sample is quantified. Then the frequencies are compared to each other. A method is also provided for using that clastogenic signature to identify a clastogenic agent or dosage to which the cells have been exposed.

Eberhard A. Spiller, Paul B. Mirkarimi, Claude Montcalm, Sasa Bajt, and James A. Folta
Method to Adjust Multilayer Film Stress-Induced Deformation of Optics
U.S. Patent 6,134,049 October 17, 2000
Stress-compensating systems that reduce stress in a multilayer without losing reflectivity and reduce total film thickness, compared to the thicknesses produced by the earlier buffer-layer method. The stress-free multilayer systems contain two different material combinations of opposite stress, both giving good reflectivity at the design wavelengths. The main advantage of this multilayer design is that stress reduction does not require the deposition of additional layers, as in the buffer-layer approach. If the optical performance of the two systems at the design wavelength differ, the system with the poorer performance is deposited first, and then the system with better performance is added, forming the top of the multilayer system. The components for the stress-reducing layer are chosen from among materials that have stress opposite to that of the preferred multilayer reflecting stack and simultaneously have optical constants that allow good reflectivity at the design wavelength.

James E. Trebes, Perry M. Bell, and Ronald B. Robinson
Miniature X-Ray Source
U.S. Patent 6,134,300 October 17, 2000
A miniature x-ray source using a hot filament cathode. The source is sized on the millimeter scale and is capable of producing broad spectrum x-ray emissions over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high-voltage feedthrough for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pumpdown and crimpoff, and a high-voltage connection for attaching a compact high-voltage cable to the high-voltage feedthrough. At least a portion of the vacuum tube wall is fabricated from materials highly transparent to x rays, such as sapphire, diamond, or boron nitride.

Conrad M. Yu and Jackson C. Koo
System and Method for Preconcentrating, Identifying, and Quantifying Chemical and Biological Substrates
U.S. Patent 6,134,944 October 24, 2000
The system and method consist of an input valve that directs a volume of sample gas to a surface acoustic wave (SAW) device where a mass of a substance within it is preconcentrated and detected. Some of this sample gas containing the preconcentrated substance is directed through an output valve to a gas chromatograph (GC) where the preconcentrated substance is then identified. A shunt valve exhausts a volume of the sample gas equal to the volume directed to the SAW minus the volume sent to the GC.

Anthony M. McCarthy, Robert J. Contolini, Vladimir Liberman, and Jeffrey Morse
Submicron Patterned Metal Hole Etching
U.S Patent 6,139,716 October 31, 2000
A wet chemical process for etching submicrometer patterned holes in thin metal layers using electrochemical etching helped by a wetting agent. In this process, the wafer to be etched is immersed in a wetting agent (such as methanol) for a few seconds before it is inserted into an electrochemical etching setup. The wafer is kept horizontal during transfer so that a film of methanol continuously covers the patterned areas. The electrochemical etching setup includes a tube that seals the edges of the wafer to prevent the loss of methanol. An electrolyte composed of 4:1 water:sulfuric acid is poured into the tube, and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte and all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100-millisecond pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process etches uniform patterned holes in the metal layers (such as chromium and molybdenum) of the wafer without adversely affecting the patterned mask.

Joe N. Lucas
Method for Detecting a Pericentric Inversion in a Chromosome
U.S. Patent 6,140,057 October 31, 2000
A method is provided for determining a clastogenic signature of a sample of chromosomes by quantifying a frequency of a first type of chromosome aberration present in the sample; quantifying a frequency of a second, different type of chromosome aberration present in the sample; and comparing the frequency of the first type of chromosome aberration to the frequency of the second type of chromosome aberration. A method is also provided for using that clastogenic signature to identify a clastogenic agent or dosage to which the cells were exposed.

Roger D. Aines, Robin L. Newmark, and Kevin G. Knauss
Thermal Treatment Wall
U.S. Patent 6,142,706 November 7, 2000
A thermal treatment wall emplaced to perform in situ destruction of contaminants in groundwater. Thermal destruction of specific contaminants occurs by hydrous pyrolysis-oxidation at temperatures achievable by existing thermal remediation techniques (electrical heating or steam injection) in the presence of oxygen or soil mineral oxidants such as manganese oxide. The thermal treatment wall can be installed in a variety of configurations, depending on the specific objectives, and can be used to clean up groundwater contamination in situ, rather than extracting contaminated fluids to the surface for cleaning. In addition, the thermal treatment wall can be used for both plume interdiction and near-wellhead in situ groundwater treatment. Thus, this technique can be used for a variety of groundwater contamination problems.

William M. Greenbaum
Active Alignment-Contact Verification System
U.S. Patent 6,143,989 November 7, 2000
A system involving an active (that is, electrical) technique for the verification of (1) close-tolerance mechanical alignment between two components, and (2) electrical contact between mating through an elastomeric interface. For example, the two components may be an alumina carrier and a printed circuit board, two mating parts that are extremely small and high density and require alignment within a fraction of a millimeter, as well as a specified interface point of engagement between the parts. The system comprises pairs of conductive structures defined in the surface layers of the alumina carrier and the printed circuit board, for example. The first pair of conductive structures relate to item (1) above and permit alignment verification between mating parts. The second pair of conductive structures relate to item (2) above and permit verification of electrical contact between mating parts.

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UCRL-52000-01-3 | March 26, 2001