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[Sandia Lab News]

Vol. 56, No. 22                Nov. 12, 2004
[Sandia National Laboratories]

Albuquerque, New Mexico 87185-0165    ||   Livermore, California 94550-0969
Tonopah, Nevada; Nevada Test Site; Amarillo, Texas

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Shane Speas preps z machine for test

John Wagner discusses Sandia work in bio cognition Women gather to talk science and career at Lawrence Berkeley Laboratory
Imaging the maelstrom about Z’s center:
Now we can do it
Labs researchers share their work at annual biotech conference National laboratory women gather at LBL to explore employee pipeline issues  

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Imaging the maelstrom about Z’s center: Now we can do it

By Neal Singer

Peering into the center of Sandia’s Z machine as it fires had been a feat unachievable for a decade.

“The energies in there are insane,” says Sandia researcher Daniel Sinars (1673) of the maelstrom of X-rays released at Z’s firing.

Sandia researcher Daniel Sinars

Other than a nuclear bomb, Z is the most powerful generator of X-rays on the planet. Last year, its central mechanism, called a Z-pinch, fused isotopes of hydrogen to create nuclear fusion.

Now, by inserting a two-inch-long crystal that reflects only a single frequency, Dan’s group has managed to visually filter out the bedlam of more than 99 percent of the energies generated by Z. Using the energy of a relatively weak laser beam passing through Z and reflecting off the crystal, the researchers have emerged with a series of pictures of the machine’s key process — the dissolution of a wire cage (about the size of a spool of thread) into ionized gas particles.

By viewing the dissolution nanosecond by nanosecond, Z experimentalists will be able to understand more rapidly and accurately how changes to the wire array will affect the final outcome, in order to fine-tune Z’s driving forces.

These alterations will achieve still more powerful outputs for weapons studies and, eventually, controlled nuclear fusion that could produce unlimited energy from seawater.

(The particles, contracted by a huge magnetic field, must be arranged to strike the central axis of the vanishing cage as simultaneously as possible to generate maximum X-rays; these already have been used to fuse pellets of deuterium.)

But how did Dan’s team do it?

Real ‘crystal power’

Expanding on work by Sergei Pikuz and Tanya Shelkovenko of the Lebedev Institute in Moscow and Cornell mentor David Hammer, who each had worked on far smaller machines, Dan realized that while the Z machine released huge energies over tens of nanoseconds, it did so in a wide frequency band. He imagined shining X-rays generated by a relatively weak but single-frequency laser beam through the wire array as it crumbled. The image generated would be reflected by a crystal functioning in only that same frequency, spherically curved for better focus on a carefully placed external detector.

Almost all of Z’s energies would be eliminated because they would not be reflected by the crystal — as eerie a phenomenon as vampire images absent inhorror-movie mirrors — leaving the laser-generated image — a picture resembling a dental X-ray — unblotched. The laser’s energies — though only one-millionth as energetic as Z’s total output — would dominate in that one band, and from it, Dan’s team would create images of the wire cage’s dissolution.

“Until our work, virtually every diagnostic on the Z facility simply measured the luminous self-emission from the z-pinch mass as it assembled on-axis and radiated,” says Dan. “We have been able to observe plasma stages at any point in the process, not just the final stage when the plasma is radiating X-rays.”

A grain of sand in a sand pile

The images provide quantifiable information about where the plasma mass is located, whether instabilities exist at any moment, what the wavelength and amplitude of such instabilities are, and where these instabilities are spatially correlated over large distances.

Says Pulsed Power Sciences Center director Jeff Quintenz (1600), “That Dan can extract such detailed images from that maelstrom environment using such a small amount of energy is more than impressive. It’s like being able to find a grain of sand in a sand pile, or a single voice in a crowded coliseum.”

Says Cornell physics professor Hammer, Chair of the American Physical Society’s Plasma Physics division, “Dan has extended backlighting work done elsewhere, but he has done so in the most extremely difficult environment. His implementation had to be novel to make it work. His work contributes major understanding of the critical dynamics of the Z-pinch.”

What the Sinars group saw

The images showed that wires in the high-energy machine do not uniformly disintegrate, as was once thought. Current passing through the wires at first heats and melts them as expected, but only a portion of the metal becomes plasma. Because plasma is so much more conductive than the heated liquid metal “cores,” much of the electrical current is diverted from heating the wires and instead flows in the tenuous plasma surrounding the dense wire cores. The plasma — continually swept inward by the magnetic forces acting on the array — is replenished with material from the dense cores. The dense cores persist for relatively extended periods of time, eventually burn through, and only then are swept inward.

“The non-simultaneous arrival of the mass on the axis is believed to be the limiting factor on the peak radiation power achievable using wire-array z-pinches, so it is critical for us to understand exactly how the wire array mass assembles on the axis,” says Dan. “This information is critical to improving our still-primitive understanding of why z-pinches work as well as they do.”

The results — the first pictures achieved of a large pulsed-power facility’s wire-cage dissolution — will be the subject of an invited talk by Dan at the upcoming American Physical Society’s Division of Plasma Physics meeting in Savannah, Ga., Nov. 15-19.

Z produces one to two million joules of X-rays in 100 to 200 terawatt bursts. The crystals reflect at either 6.648 or 2.015 angstroms.


-- Neal Singer

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Labs researchers share their work at annual biotech conference

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By Chris Burroughs

From adapting a Sandia-developed decontamination foam for sterilization of cattle trucks to detecting early stages of gum disease with a hand-held chem lab on a chip, Labs scientists shared their research during the fourth annual BioScience and Technology Symposium (BS&T) Oct. 26-27 in Santa Fe.

Some 100 researchers from Sandia/New Mexico and Sandia/California attended the symposium filled with presentations on work they are doing in the area of bioscience and technology.

“I found this to be a very exciting day and half,” said Julia Phillips, Director of Physical, Chemical, and Biomolecular Science Center 1100 and chair of the Sandia BS&T Council. “Sandia’s biotech effort has grown considerably from the little nucleus it started with not too many years ago.”

A revised symposium format let attendees hear from leaders of Strategic Management Units (SMUs) that have some biotech components associated with them and learn about their colleagues’ work.

Julia said interest in biotech is growing at the Labs. In the FY05 Laboratory Directed Research and Development (LDRD) funding cycle, 60 proposals had biotech components. Of those, 25 were funded, representing about 10 percent of all the LDRD awards.

“The LDRDs span across all areas,” she said. “As a result the [BS&T] council felt it was a good time to bring everyone together to get a sense of the breadth of what people are working on and the mission drivers for the work.”

Anup Singh (8321) told about his efforts to develop a chem lab on a chip to use in detecting gum and heart disease. Chem lab on a chip, formally called µChemlab™, is a Sandia initiative to build a hand-held “chemistry laboratory” the size of a palm-top computer. The adaptation of using it for medical purposes came about because of new funding from outside sources, Anup said.

A Sandia-developed decontamination foam used in the past to kill anthrax is now being studied as a way to disinfect farm equipment hauling cattle to ensure that meat supplies are safe, said Bruce Kelley (6245). This is just one of the many agriculture/bio activities in Division 6000 he talked about.

Some of the other topics and their presenters at the symposium were Single Molecule Approach to Biophysics, Khai Luong (8353); Protein Microarrays for Biowarfare Agent Detection, Amy Herr (8321); Biomedical Projects in 15200, Kelly Jorgensen (15233); Bio/Micro Fuel Cell Grand Challenge Project, Kent Schubert (1763); Bio Cognition Work in 15000, John Wagner (15241); Interaction of Proteins with Lipid Films, Mike Kent (1812); Biological Weapons Nonproliferation, Ren Salerno (6928); and Studies of Signaling/Domains in Model and Biological Membranes, Alan Burns (1116). A wide variety of other work was presented at a poster session.

Following the presentations, directors present talked about how successful the event was and what still needs to be done in the area of biotech.

“I reflect back eight or nine years ago when Mim [John, VP 8000] was trying to convince the SMUs that chem/bio was important,” said Marion Scott, Director of Microsystems Science, Technology & Components Center 1700. “It was a difficult sell. Today it’s not a difficult sell.”

Director of the Center for Exploratory Systems and Development 8100 Rick Stulen noted that while the symposium was excellent, “we are still struggling to put together a coherent story around bio. We still have our work cut out for us. It requires everyone to pull together.”

Julia said that the biotech work at Sandia was all about interfaces.

“It’s interfacing science, technology, and engineering,” she said. “Sandia is choosing the science problems we attack with national security in mind. We may see results of this work decades in the future.”

The second interface she said is occurring between various Sandia organizations, while the third involves Sandia’s partnering with outside organizations.

“We are giving more careful thought to our external partnerships. We are transitioning from being a contributing partner to leading more of these partnerships,” she said

The final interfaces she noted are between disciplines — bio, micro, nano — and between various funding agencies.
-- Chris Burroughs

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National laboratory women gather at LBL to explore employee pipeline issues

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By Nancy Garcia

“Widening the winner’s circle” is how Rep. Ellen Tauscher, D-Calif., described the way the US will retain dominance in the 21st century in her remarks at the third Laboratory Women’s Forum, “Women of Influence at the National Laboratories.”

Convened at Lawrence Berkeley National Laboratory (LBL) last month, the forum was attended by more than 150 participants from Sandia, Lawrence Livermore, Los Alamos, and Lawrence Berkeley national laboratories.

Richard Nolan, director of the Berkeley Site Office of DOE’s Office of Science, echoed Tauscher’s message. Attracting and retaining talent, he said, is of critical importance to DOE and to the world because under-utilization of women seriously impinges on the security needs of the nation. “It’s clear we need you,” he said, “to lead us forward into the 21st century.”

Women in science/technology

Although women represent about half the workforce, they accounted for only 19 percent of the science and technology sector in 1991 and 26 percent in 2003, he said, although that sector was growing more quickly than the rest of the workforce.

Tauscher experienced changing opportunities when she was one of the first women to join the New York Stock exchange after graduating from college in 1974. “Globalism hit financial markets before any other business,” she said. “They needed people and talent. This was the wave of the future.”

Tauscher inspired the first forum by asking laboratory women in Livermore to contribute ideas to the Commission on the Advancement of Women and Minorities in Science, Engineering, and Technology Development. Held in San Ramon in 2000, it resulted in policy recommendations regarding recruitment, recognition, workplace flexibility, and the image of women in technical fields. Two of the recommendations were forwarded to the National Academy of Sciences Commission on Women in Science and Engineering, said Jane Ann Lamph (8755), who recapped progress in remarks at the most recent forum.

Policy, benefit proposals

Judy Moore (16000), co-chair for the Sandia Women’s Action Network, added that Sandians followed up by proposing policy and benefit changes to make Sandia an employer of choice. Her co-chair Georgianne Smith (3000) attended with others in Albuquerque by videolink.

“We really have taken action and made a difference,” said Deputy Director Pat Falcone (8110).

Los Alamos women, who learned about Sandia’s ombuds program, established one there, said LANL Technical Staff Member Wendee Brunish. Although women make up 32 percent of the workforce, they account for 52 percent of the ombuds clientele, she noted.

Lawrence Livermore women focused on championing having more women in middle and upper management, which resulted in several upper-level recruitments, including Associate Director for Computation Dona Crawford, a former director from Sandia/California (she had been a panelist at the first forum and introduced Tauscher at this forum).

The host of the October forum, LBL’s Chief Facilities Planner Laura Chen, said she was the sole participant from her facility at the second forum, held in 2002 in Albuquerque. The recently appointed LBL director, Steven Chu, kicked off the forum with remarks about how the laboratories can be made more hospitable. “Things are getting better,” he concluded. “But things can be a lot better.”

California Laboratory Vice President Mim John spoke about the impacts of nationalscience and technology issues on the labs. “The world has changed,” she said, with the threat of a massive nuclear attack diminishing but the acquisition of nuclear capabilities growing. She called for the labs to engage in the policy debate as well as technical solutions, saying, “The challenges are enormous. The nation expects us to be there when we’re needed.”

Karen Ramorino, deputy of the Administrative Services Department of LBL, spoke about workforce demographics. She said that among technical workers, the ranks of women who were unmarried, had nonworking spouses, or saw work-life balance as an obstacle were 34 percent, 10 percent, and 21 percent, respectively, while for men, the numbers were 17 percent, 38 percent and 2.8 percent. (The statistics are from a 2004 paper by Shirley Tilghman of Princeton University, “Ensuring the Future Participation of Women in Science, Mathematics and Engineering,” online here.)

Ramorino also said that men can be as effective as women as role models.

Also speaking from LBL was Deputy Director Pier Oddone, who described how successful women can also be role models for men. Instituting improvements over time, he said, is an effort that has to be carried out in parallel and on many fronts.

That was essentially Tauscher’s call to action. “There are millions of young girls out there,” she said, “and our work is to build a ladder for them to places we couldn’t go. Unless we make this part of our own personal agenda, we cannot make sure this will be done. We will find the way, because we are meant to do it. It is for our legacy that they will work.” -- Nancy Garcia


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Last modified: November 11, 2004

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