Sandia LabNews

LDRD stars illuminate their work

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On a stage empty of décor in Bldg. 962 in Tech Area 4, six youthful-appearing LDRD (Laboratory Directed Research and Development) presenters captured the attention of a small audience of about 40 with the intensity of their descriptions of their projects.

The noise level rose afterward when a rotating flux of some 50 Sandians inspected 36 posters describing other LDRD efforts.

“It’s about interacting, not just listening,” said LDRD manager Hank Westrich (1011) approvingly of the freewheeling discussions. The location was chosen because of the large room available for poster presentations.

The oral and poster sessions were preceded by a fact-filled opening talk by Sandia Div. 1000 VP Rick Stulen, who explained the evolving basis for winning the coveted three-year funding, which the Labs has used to develop promising new technologies.

In official terminology, these start-up funds are the “seed corn” of the Labs, which “nurture its core, support its missions, and drive its future,” said Rick.

The program’s history and results are indeed unusual.

According to Rick’s figures, early-stage LDRD grants have supported 60 percent of Sandia’s R&D 100 award winners since 1992. (R&D 100 award winners are determined yearly by independent judges selected by R&D Magazine from projects submitted to the competition from around the world. The projects must show enough development, in addition to original research, to make a difference in the world’s technologies.)

In addition, LDRD funds have supported five of Sandia’s 10 most highly cited publications from 2002-2006. (The number of citations a research paper receives in the papers of later researchers is thought to be a key indicator of its importance.)

“The impact of the [nearly $150 million] LDRD program far exceeds the 8 percent of Sandia’s budget it represents,” Rick said.

A deliberately slimmed-down reviewing process now allows PIs “to devote more time to research rather than paperwork,” he said. In addition, the formerly opaque process has been changed to provide “insightful comments back to PIs, which they seem to appreciate,” he said.

Perhaps surprisingly, Rick’s tables showed that the average start-up project size had increased into the $400,000 range, with a decline in projects in the less-than-$100,000 range. “Don’t hesitate to propose $500,000 to $700,000 programs that will make an impact, even in activities that may not see the light of day for five to 10 years,” he said.

“There’s a myth at the Labs that LDRDs [projects] are only occupied by folks in mid and late career who know how to work the system,” said Rick. Projecting a graph that showed a breakdown of participants by age, he said, “As you can see, almost 50 percent of funding recipients have been here less than five years. Twenty percent have been here five to ten years.”

By accident or design, the speakers seemed to embody the youthful appearance of the figures presented by Rick.

Dahv Kliner (8368) presented ongoing work in the Fiber Laser Grand Challenge, which is developing a new generation of compact, rugged, high-power lasers based on fiber optics. The group has achieved a peak power of more than 1 MW from a single fiber, a factor of 100 beyond the conventional “single-mode limit.” This performance was achieved using the patented coiling technique, first published by Sandia researchers in 2000, that has become the de facto worldwide standard for power scaling of fiber sources. The method has been licensed for industrial applications and was a recipient of this year’s R&D 100 Award.

Dahv pointed out that the peak in-fiber irradiance is beyond the damage threshold for fused silica reported in some studies. Further Grand Challenge research has shown that these earlier reports were incorrect, and the fundamentally new understanding of optical damage is “rewriting the textbooks,” with significant implications for high-power laser optics in general. The high-profile program is now entering its fourth and final year of LDRD support.

Shanalyn Kemme (1725) discussed her efforts to manage a body’s thermal emission through use of a thin, textured coating. The coating enables an effect called plasmon/photon coupling. Plasmons are waves of electrons that move parallel to the surface of an object. Through optimum choice of coating material and surface texture parameters (such as grating period and depth), both the angular pattern and wavebands of thermal emission can be shaped.

The method works because a sub-wavelength grating provides phased coupling between the incoherent thermal mode and coherently radiated photons. Key to this mechanism is the subwavelength diffractive optic. Its parameters determine the efficiency of the coupling, angles of radiation, and wavelengths emitted. Small pieces of this coupling diffractive optic will be added to a binder and painted conformally onto an object, she said, so that it should appear almost invisible to heat-detecting instruments.

Hongyou Fan (1815) described his group’s success in reducing defects in the epitaxial growth of single-crystal semiconductor materials. The work contributed to winning an R&D 100 award this year, and was also selected for a 2007 LDRD Award for Excellence. Hongyou and his team developed photolithographically defined and self-assembled carbon nanostructures to provide the first hierarchical growth templates for defect reduction in wide bandgap semiconductor heteroepitaxy. The work, which he said may impact all forms of heteroepitaxy, is tightly aligned with Sandia’s solid-state lighting initiative and the next generation of RF electronics.

“Defect-reduction strategies for group III nitride semiconductors are of immense technological importance,” he said. Use of combined lithographically and self-assembled templates offers freedom from conventional top-down etched-template approaches, he later explained, and hence new opportunities. More importantly, the porous carbon materials exhibit what he feels to be ideal structure and framework chemistry for water purification, nuclear waste treatment, sensors, catalysis matrices, energy conversion and storage.

Winning two awards, joining Sandia as a PMTS, and the Sept. 1 birth of an 8.5-pound daughter named Cindy have made this a pretty good year for Hongyou.

Mark Boslough’s (1433) gut-wrenching simulations of asteroids hitting Earth improved upon science fiction renditions of the same phenomenon by offering new information about the effects of such impacts. Formerly thought to be chiefly a downward thrust that dug out significant craters in earth, Mark’s use of Sandia’s CTH codes on the Red Storm supercomputer has demonstrated that small cratering events can actually involve large airbursts with incandescent fireballs in contact with a surface area of hundreds of square kilometers for tens of seconds.

Explosions may occur above the Earth, he said, when the exponentially increasing air resistance causes an exponentially increasing broadening of the incoming asteroid.

While Mark’s work did not involve creation of a new device, Sandia senior LDRD manager Wendy Cieslak (1010) pointed out that any possible assault on Earth that did not have an upper limit on the damage it could do — as asteroids do not — was clearly a province for exploration by a national security laboratory.

Tammy Kolda (8962) showed computer codes could use mathematical matrices to combine disparate data sources, such as email, telephone, open source, and cell phone data, into a single report that could be mined for particular information. The novel methods for mathematically analyzing graphs include automatically grouping and labeling hyperlinked web pages according to their importance and topic. The approach relies on tensor decomposition methods, which is a new approach to graph and data analysis.

Two new software packages were developed as part of this work: The Tensor Toolbox for Matlab for computations on tensors and TaMALE for graph visualization. The research breaks new ground in cyber security applications.

David Gill (2455) discussed his group’s creation of optimized, light-weight, high-strength structures for aerospace applications. His group used a new code for structural optimization based on Sandia’s extended finite-element method (X-FEM) code, and then partnered with University of Rhode Island to develop generalized 3-D structural optimizations.

In the past, he told the Lab News, such computer renditions weren’t helpful because the topologically optimized structures couldn’t be fabricated by ordinary manufacturing processes. These start with a block of material from which sections are cut or etched away. But using Sandia’s LENS® (Laser-Engineered Net Shaping™), a trademark additive manufacturing process which creates objects out of laser-heated powders, the structures were created. They combine high strength with the lowest possible weight. The project is called, mysteriously enough, “titanium-cholla” because titanium is one of the chief materials for aerospace applications and the structure of the dried cholla cactus is like an optimized torsional beam, which could be used to lighten an automobile driveshaft while maintaining strength comparable to current designs.

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Winners of the 2007 LDRD Award for Excellence are:

  • Nanolithography Directed Materials Growth and Self-Assembly Principal investigator: Julia HsuFor pioneering work on controlled growth and assembly of oxide nanostructures on surfaces and for furthering the understanding of heteroepitaxial growth of dissimilar materials.
  • Microwave to Millimeter Wave Electrodynamic Response and RF Applications of Semiconductor Quantum Nanostructures Principal investigator: Mark LeeFor opening a new frontier in high-frequency nanotechnology by exploiting the quantum mechanical properties of semiconductor nanostructures for microwave and millimeter-wave applications.
  • Controlled Fabrication of Nanowire Sensors Principal investigator: Francois LeonardFor developing a fundamental understanding of nanowire-based sensors: synthesis, assembly, characterization, and modeling.
  • Just in Time Jamming of Enemy Detonation Signals Principal investigator: Larry BaconFor developing a responsive RF jammer that selectively jams in narrow frequency range.
  • Nanoporous Films for Epitaxial Growth of Single Crystal Semiconductor Materials Principal investigator: Hongyou FanFor developing photolithographically defined and self-assembled carbon nanostructures to provide first-of-a-kind hierarchical growth templates for defect reduction in wide bandgap semiconductor heteroepitaxy.
  • Bead-based Multiplexed, Orthogonal, BW/ID BioWarfare/Infectious Disease Detection Microsystem and Technologies Principal investigator: Paul GalambosFor leading a multidisciplinary team in a high-risk, innovative approach to the simultaneous detection of chemical/biological agents and radionuclides in raw samples.

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