Page top
Skip navigation



2005-2006 HIGHLIGHTS








Cover of the 2006 Annual Report
Annual Report

PDF (10 MB)
Cover of the 2006 College Directory
College Directory

PDF (5 MB)


Content begins

A 40-degree slice of the ITER (formerly International Thermonuclear Experimental Reactor)

Assessing radiation transport through materials is easier, thanks to CAD code that enables more precise geometric modeling. Here, a 40-degree slice, in volume format, of the International Thermonuclear Experimental Reactor (ITER). (Large image)

Engineering Physics

Designing ways
to help ITER operate safely

Fusion Technology Institute (FTI) researchers are playing a key role in ITER, or the International Thermonuclear Experimental Reactor, a multinational project designed to demonstrate the scientific and technological feasibility of fusion power. It will take nearly a decade to build; construction will begin in Cadarache, France, in 2007.

Each participating entity—the United States, China, the European Union, India, Japan, the Republic of Korea and the Russian Federation—will design, analyze and build certain components of ITER.

Paul Wilson, Mohamed Sawan, Tim Tautges and Greg Sviatoslavsky

Assistant Professor Paul Wilson, Research Professor Mohamed Sawan, Adjunct Professor Tim Tautges and Researcher Greg Sviatoslavsky (Large image)

Research Professor Mohamed Sawan is leading the FTI team, which includes Assistant Professor Paul Wilson, Adjunct Professor and Sandia National Laboratories Scientist Tim Tautges, and Researcher Greg Sviatoslavsky.

FTI researchers are leading the U.S. portion of the ITER neutronics analysis, which ensures that sensitive ITER components can withstand the high-energy neutrons produced during fusion. To achieve a quicker, more accurate analysis, the group is integrating the neutronics code with a CAD modeling engine that draws on an external library of CAD-created geometries.

FTI researchers also are helping design and analyze tritium breeding test blanket modules, which test technologies needed in future fusion power plants. Working with ITER designers, they are modeling the reactor’s diagnostic ports to assess whether components such as cables, fiber optics and detectors can withstand radiation damage. They are collaborating with Sandia researchers to ensure the three U.S. first-wall shield modules have adequate cooling and can handle the experiment’s highest heat flux and radiation levels.

Directed by Grainger Professor Gerald Kulcinski, the FTI has received approximately $600,000 in 2006 Department of Energy funding for these ITER initiatives.

Good heavens: Space telescopes may have steadier view

University of Wisconsin-Madison research may help large-aperture space telescope engineers ensure that future multimillion-dollar instruments provide a clear view of objects in space and on Earth. On-ground physical testing and mathematical modeling are key indicators of how these telescopes will perform in space. Particularly important is how they respond to and adjust for vibration, says Professor Dan Kammer. “If you’re worried about being able to predict very small deformations, that means you’ve got to worry about very high-frequency vibrations,” he says.

Researchers compare physical vibration tests with mathematical predictions. If the out-comes match, then they can further simulate how the telescope will operate under a range of load conditions. However, while such test-validated mathematical modeling is standard for even complex spacecraft, it’s not accurate enough for a finely tuned space telescope.

The current technique centers around characterizing a structure’s mode shapes—the shapes in which it naturally vibrates—and frequencies, or rates at which it naturally vibrates. For a spacecraft, that might mean a range of frequencies between zero and 50 hertz. Because a large-aperture telescope is sensitive to even small vibrations, the frequency range widens to about 300 hertz and it’s nearly impossible to discern one mode shape from the next.

As an alternative, Kammer is developing a new model-verification technique based on the structure’s frequency response: If researchers exert a force on a structure at a certain frequency, it responds at that frequency. “I can measure that in a test,” says Kammer. “And I can predict that using my mathematical model.”

Funded by the Air Force Office of Scientific Research, Kammer also is establishing metrics, or measures of how accurate the analysis prediction is in relation to the physical tests.

A “hot” idea for insulating tiny batteries

Engineering physics researchers are devising a unique “blanket” that will enable them to squeeze as much electricity as possible from nuclear-powered batteries the size of a grain of coarse salt. Such batteries, which exploit the natural decay of radioisotopes to generate electricity, could provide virtually indefinite power for micro-technologies like remotely placed sensors or fly-sized robots.

When the batteries are hot, electricity conversion is more efficient, so it makes sense to insulate them, says Professor James Blanchard. However, insulating a millimeter-square battery in a way that minimizes heat loss is no easy task.

Multifoil insulation, an effective macro-level insulator that combines several thin layers of foil each separated by a vacuum, is far too thick. So, capitalizing on the layered concept, which reduces heat radiation for a fixed temperature drop, Blanchard and graduate student Rui Yao sandwiched silicon oxide pillars between very thin silicon sheets. They also built elaborate computer models to study heat radiation and conduction.

Funded by a three-year, $300,000 Department of Energy grant and inspired by an earlier collaboration with Sandia National Laboratory researchers, Blanchard and Yao are still testing and refining the insulation. Implementation for this promising technology, they say, is a couple of years down the road. “It looks like we’ll have an effective insulator that’s better than any solid—and better, even, than some of the multifoil insulations that you can buy commercially,” says Blanchard.

Back to page topEnd of page