The NIF target chamber is dedicated

At June 11, 1999, ceremonies at Lawrence Livermore, Secretary of Energy Bill Richardson was joined by Director Bruce Tarter and senior defense officials from the United Kingdom and France to dedicate the 130-ton target chamber built for the National Ignition Facility (NIF). All employees and their families were invited to the dedication.
NIF, the largest laser in the world, will be a cornerstone of the DOE Stockpile Stewardship Program, which will keep the U.S. nuclear arsenal safe and reliable without underground nuclear testing. Tarter stated his confidence in NIF to fulfill this purpose. "I am very optimistic about our ability in the long term to meet that challenge," he said. With both Britain and France collaborating on the project, Secretary Richardson pointed out that NIF is a model of true international cooperation.
The dedication of the target chamber marks the on-time completion of the first and largest piece of equipment for the laser's operation. It also marks the halfway point in construction.
Contact: Gordon Yano (925) 423-3117 (yano1@llnl.gov).

Lab's new gas chromatograph works on the spot

Lawrence Livermore's miniature gas chromatograph is making it faster and easier to identify what's in samples of air and water. The device, weighing about 5 pounds and requiring just 2 minutes to analyze liquid and gas species to sensitivities of parts per billion, contrasts with previous chromatographs that have taken hours, even days, to process samples and were too large to be deployed where chemical weapons or poisonous gases were suspected of being released.
The new, portable device results from work in Livermore's Center for Microtechnology. Engineer Conrad Yu scaled down the chromatographs's column, where the various constituents of the sample are separated before being directed to a detector for counting. Previous attempts to scale down the column were unsuccessful because they could not keep the column perfectly circular, which is crucial for analytical accuracy.
Yu etched perfect half circles on two silicon wafers-similar to those used for computer chips-and then lined up the semicircles and bonded them together. He was thus able to make a circular column 100 micrometers wide and several meters long. The chromatograph's smaller column allowed the associated detector and computer to be scaled down also.
The new chromatograph will have many potential applications in medicine, industry, law enforcement, and environmental cleanup. Yu and colleagues want to make this technology commercially feasible within several years.
Contact: Conrad Yu (925) 422-7356 (yu1@llnl.gov).

Burst bubbles support astrophysicists' theory

Lawrence Livermore astrophysicist Richard I. Klein, UC Berkeley astronomy chair Jonathan Arons, and UC Berkeley Space Sciences Laboratory's J. Garrett Jernigan have found evidence to support a theory about powerful x-ray emissions from neutron stars-rotating, magnetized, collapsed stars that are some of the most violent objects in the universe. Ten years ago, Klein and Arons posited that when a neutron star pairs up with another star, its powerful gravitation siphons off material from the second star. That material is channeled to the neutron star's polar caps, where it creates an unusual field of radiation, or photon, bubbles. The bubbles merge and burst, releasing a shower of high-frequency x rays in a more or less regular fashion, causing the neutron star to flicker or oscillate.
Jernigan, involved in developing NASA's Rossi X-Ray Timing Explorer satellite since its inception, suggested using it to look for radiation bubbles. For the search, the scientists selected the neutron star Centaurus X-3, some 30,000 light years away in the Milky Way galaxy.
For three days, they took satellite measurements and obtained data whose analysis showed the x-ray emissions flickering at rates from 100 to 2,000 times per second, a range the scientists had earlier predicted. "This is the fastest known x-ray emission of any collapsed star in the universe, be it a white dwarf, black hole, or neutron star," Klein said. "The discovery lends strong support to our theory that the origin of these rapid x-ray fluctuations is the exotic photon bubbles we predicted."
Klein, Arons, and Jernigan reported their findings at a recent meeting of the High Energy Astrophysics Division of the American Astronomical Society in Charleston, South Carolina.
Contact: Richard I. Klein (925) 422-3548 (rklein@llnl.gov).

DNA analysis in the field

At Livermore's Center for Microtechnology, scientists have developed a battery-powered DNA analyzer that can quickly detect and identify microbial pathogens in biological weapons or outbreaks of infectious disease. The portable device can be operated in the field to provide critical information in a matter of minutes. Ray Mariella, director of the center, said the device "can be used in various settings, such as a hospital emergency room, where rapid analysis of samples is needed."
Called the Advanced Nucleic Acid Analyzer (ANAA), the instrument uses the polymerase chain reaction, or PCR, to produce millions of copies of an organism's identifying DNA. As the PCR progresses, synthesized complementary DNA probes, tagged with fluorescent dye and designed to attach to specific bacterial organisms, are added to the reagent. A DNA copy is measured for fluorescence to determine the presence or absence of a particular organism.
The ANAA development team is at work on a next-generation, handheld version of the device and aims to have a prototype later this year.
Contact: Ray Mariella (925) 422-8905 (mariella@llnl.gov).

Improving the viability of tissue welding

Researchers in Livermore's Laser Programs Directorate have developed a device that more easily and accurately measures heat resulting from tissue welding. The measurements provide feedback signals used to control a laser's output and thus maintain a preselected temperature at the tissue welding site. The device improves the viability of laser-based surgical welding, which is still in the research stage. It can also have a variety of other applications, medical and nonmedical, where control of laser temperature is critical.
The device is a two-color, mid-infrared thermometer that uses a single glass optical fiber to provide dynamic, noncontact temperature and emissivity measurements quickly and at a high spatial resolution. Peter Celliers, laser physicist, said that because of the nature of the fiber used to collect radiation, scientists can zero in on very small points in the tissue, thus helping them obtain more accurate temperature measurements.
The work is part of a Cooperative Research and Development Agreement with Conversion Energy Enterprises of Spring Valley, New York. Conversion Energy has successfully demonstrated a laboratory prototype of the device. An upgrade is in progress, with the engineering being done jointly by Conversion Energy and Lawrence Livermore.
Contact: Peter Celliers (925) 424-4531 (celliers1@llnl.gov).

The last laser shots from Nova

For 15 years, the Nova laser at Lawrence Livermore had the distinction of being the world's largest laser. But with the National Ignition Facility (NIF) on the way to replacing it, Nova was retired and its components shipped off to DOE laboratories and university research centers across the country.
In late May, Nova fired its final shots in service to the nation's defense and energy projects. Although NIF is expected to be 50 times more powerful, it was Nova's work-some 14,000 experiments on its 10 separate beams-that paved the way for NIF power. Said Joe Kilkenny, deputy director of the Inertial Confinement Fusion program, "It's lasted far longer than anyone expected," adding that through Nova, "we've learned how to get more bang for the buck."
Early experiments on Nova tested the ability of the laser to convert its energy into x rays. Nova has helped researchers to better understand nuclear weapons explosions and the cores of the sun and planets. It has provided clues about radiation emitted by the intensely bright stars known as supernovae. Furthermore, the laser has created some spin-off medical technologies, aiding research to eliminate scar tissue from angioplasty surgery and to use sound waves through the blood stream to break up clots.
Now, as Nova joins its predecessor lasers-Janus, Cyclops, Argus, and Shiva-a comparable facility at the University of Rochester in New York will stand in its place until NIF is ready.
Contact: Joe Kilkenny (925) 423-4213 (kilkenny1@llnl.gov).
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