Bluefield Daily Telegraph, Bluefield, WV

Local News

March 7, 2011

All eyes are on rare electron microprobe at Concord University

ATHENS — It looks a little like a starship-shuttle cockpit from an old science fiction movie — but it is science fact, a high-tech tool to look into a microscopic world.

An electron microprobe, tucked away in the basement of the Concord University Science Hall, zaps tiny samples in a vacuum chamber and yields results of interest to chemists, volcanologists, metal alloy manufacturers — and, perhaps, gas and oil drillers.

And to university students, who have an opportunity unique in the state.

“There aren’t many of these (devices) around,” said Dr. Steve Kuehn, director of Concord’s geochemistry laboratory. “It’s the only one in the state. It really is remarkable, having this sort of research-grade equipment at a university of this size.”

J.L. “Joe” Allen, chairman of the university’s Division of Natural Sciences, said, “The students have been pretty excited (at) the opportunity to use some equipment and gain some skills they wouldn’t have had access to otherwise.”

New microprobes cost around $1.8 million, Allen said. The one newly installed at Concord is a “hand-me-down” from the University of Kentucky, where he once worked on the machine while doing graduate study. It was built in the 1980s but has been upgraded often since.

In fact, Kuehn had nearly identical samples sent to 24 other microprobe labs in nine countries, and reported that “our data is every bit as good as the top 5 to 10 percent” of the results.

The whole process starts with a tiny tungsten wire similar to those found in old light bulbs. This metal filament, however, is excited by a high voltage current that releases a powerful stream of electrons down through a thick-walled chamber with nearly all of the air pumped out of it.

“This thing’s built like a tank, really,” Kuehn said.

Magnets help focus the electron stream to a target area 1/1000th of a millimeter wide — or one-fiftieth the width of an average human hair. Depending on the need, the scope can pick up visual images or telltale X-ray radiation that identifies what chemical elements are present.

“The key thing is that you can determine what something is made of,” Kuehn said. “You can tell what elements are in it, and how abundant they are, even down to the trace level.”

The X-ray detection is “one of the key things that differentiate this type of instrument,” Kuehn said. A special adaptation, with the impressive name of Wavelength Dispersive Spectro-meter (WDS), allows the operator to get extremely precise measurements, down to 100 atoms out of a million a sample.

There are four of those WDS X-ray detectors on Concord’s new microprobe.

The typical run time to analyze a target spot is around 2 to 5 minutes, but Kuehn said, “the longer you count, the better your statistics.”

Luckily, the targeting is computer-run, so an operator can program in a whole series of target spots, set the time for each run, and leave the building.

“You could set it up on Friday and let it go the whole weekend, unattended,” he said. With a smile, he said, “In the old days it was a lot more tedious.”

The visual magnification is as much as 10,000 times actual size, much smaller than a typical human cell. By comparison, the more common light-gathering microscopes have a 200- to 400-times magnification.

“Really small stuff,” Kuehn said.

Allen said, “We are currently using the instrument for research in volcanology (and) climate change, and to study the physics and geology of ancient earthquakes for a study funded by the National Science Foundation.”

Kuehn described his microprobe research into thin layers of volcanic ash that he found in cores of glacier ice on the Canada-Alaska border. It could help in research about how climate has changed over the centuries.

Allen said that sampling rock from layers deep under the earth, and the “pore spaces” between mineral grains, can help petroleum researchers determine if underground basins exist in which natural gas or oil can accumulate.

Looking at data from old earthquake faults may lead to “data that helps us understand the physics about how that earthquake operated,” Allen said. “It could make it easier to protect people from future quakes.” A similar line of research could help in prediction of volcanic eruptions.

Kuehn noted, however, “This is not just a research tool. This is going to be a teaching tool.”

Allen said that undergraduate students in Concord’s petrology class have been at work in the Science Hall, preparing target samples that they will analyze in the microprobe next week.

“The students are actually doing the sample prep themselves,” he said. “They’re slicing and dicing, making thin polished sections they will put on a glass slide.”

The purchase is the end result of grants Concord received from the National Science Founda-tion; the petroleum research fund of the American Chemical Society; the “Bucks for Brains” trust fund established by West Virginia state government; and a new “Innovation Grant” awarded last month by the Division of Science and Research at the state Higher Education Policy Commission.

Kuehn said, “The university is putting in some resources, itself.” He added that the lab may be able to generate income from “external commercial users (who) pay for machine time.”

The sciences faculty will show off the new microprobe and other Science Hall equipment at a “science open house” on March 26 during Math Field Day at Concord. Allen and Kuehn are scheduled to present a scientific paper about the geochemistry lab at a meeting of the Geological Society of America later this month as well.

The location of such a sophisticated instrument in the small town of Athens may hold a unique distinction, Kuehn speculated.

“This may be the only microprobe in a town with only one traffic signal,” he said.

— Contact Tom Bone at

tbone at bdtonline.com

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