Photos by Matt Gentry | The Roanoke Times

Virginia Tech physics professor Bruce Vogelaar stands at the entrance to the Kimballton mine. The university worked out an agreement with Chemical Lime, owner of the mine, to use space there for experiments.

The entrance to the Kimballton mine in Giles County leads to a Virginia Tech research facility that sits tucked away some 1,700 feet under Butt Mountain.

Prefabricated storage containers house the equipment used in research on subatomic particles in the Kimballton Underground Research Facility. Surrounded by sedimentary rock and accessible by vehicle, the lab is the best site on the East Coast to do such experiments, says Virginia Tech physics professor Bruce Vogelaar.

Prefabricated storage containers house the equipment used in research on subatomic particles in the Kimballton Underground Research Facility. Surrounded by sedimentary rock and accessible by vehicle, the lab is the best site on the East Coast to do such experiments, says Virginia Tech physics professor Bruce Vogelaar.

RIPPLEMEAD -- Researchers at a Virginia Tech facility in Giles County are conducting experiments to better understand how the sun works.

Their location could hardly be further removed from the focus of their research.

The Kimballton Underground Research Facility sits tucked away some 1,700 feet under Butt Mountain in a cavernous limestone mine.

Visitors must drive 14 levels down a twisting maze of roads, where the only break from darkness comes from the headlights of trucks and huge mining vehicles that harvest chemical-grade lime for the Chemical Lime Co.

On a visit to the lab in mid-March, the mine's gaping entrance looked like something from a fantasy novel.

Goats huddled off to one side, steam rising above them as they clambered up rocks. Trucks rumbled in and out of the hole in the mountain, still audible long after they stopped being visible.

Freshly fallen snow reflected sunlight and illuminated the area before the first turn in the road.

To reach the mine, Chemical Lime mine engineer Chris Campbell spent more than 15 minutes driving into the earth at about a 30 degree angle, dropping roughly 80 feet a level. Butt Mountain rose higher as the truck descended.

Once inside the mine, sunlight is such a foreign concept that, when Campbell killed the lights on the truck, there was no discernible difference between what passengers could see with their eyes open or closed.

"There it is, home sweet home," said KURF director and Tech physics professor Bruce Vogelaar as he pointed to an unassuming 100-by-35-foot shell building spotlighted in the darkness.

"The best-lit place in the mine."

It's no accident that work being done in the lab is related to the study of subatomic particles -- called neutrinos -- created by nuclear reactions inside the sun. Work in the lab will detect neutrinos produced by accelerators.

"The experiments that we are doing down there basically require a very low background environment and so we go underground to get rid of the cosmic rays. And then we have local shielding to prevent radioactivity that you would get from normal rock, uranium, thorium, potassium," Vogelaar said.

Surrounded by sedimentary rock and accessible by vehicle, the lab is the best site on the East Coast to do such experiments, Vogelaar said. The universities at the Research Triangle Park in North Carolina have taken advantage of their relative proximity to run experiments in the lab, partnering with Tech.

Completed about a year and a half ago, the lab cost about $100,000 to build. Universities that use the lab contribute about $10,000 a year toward common costs, Vogelaar said.

A Duke University project is attempting to develop a large solar neutrino detector. Another experiment, Vogelaar said, "is looking at fundamental symmetries of the universe."

To look for violations of those symmetries, researchers need an environment clean of outside influences, he said.

So they work underground, inside a clean room, inside a trailer, inside a building. The university worked out an agreement with Chemical Lime, owner of the Kimballton mine, to use space there for experiments.

"Another phenomenon we'd like to understand is how stars work and how a supernova works," Vogelaar said. "We think we have a pretty good idea where the elements come from. But there are still some details that are a little mysterious.

"The sun, when it basically converts hydrogen to helium ... gives off these things called neutrinos. And amazingly we can detect these little guys and tell you directly that nuclear reactions are happening, not just a long time ago, but eight minutes ago in the very center of the sun."

While neutrinos from reactions inside the sun reach Earth in eight minutes, it takes light produced by those reactions 40,000 years to reach the sun's outer surface.

The problem is, neutrinos are so weakly interacting that they're difficult to detect. They were discovered only about 50 years ago.

Trillions of neutrinos pass through the human body every second. A neutrino could pass through a light year of lead and hit something only once. With a near-zero mass, neutrinos have a way of taking what we think we know about the concept of mass and turning it on its head, Vogelaar said.

Vogelaar, along with geosciences professor Robert Bodnar and Matthew Mauldon in civil and environmental engineering, wrote proposals to the National Science Foundation in 2004 to build a national laboratory 7,000 feet underground at Kimballton. The mine was one of seven finalists for an NSF grant to build a Deep Underground Science and Engineering Laboratory.

A mine in South Dakota was selected for the future DUSEL site, but work complementary to that project, along with stand-alone research, is ongoing at Kimballton. Some of the projects started at Kimballton will eventually be moved to the South Dakota mine when DUSEL is completed.

Some physicists doing this research seem to be happier the deeper underground they get, thus the plans for a national laboratory 7,000 feet deep.

Work will continue at Kimballton long after the South Dakota lab is up and running. There are two 10-foot trailers from the University of North Carolina at Chapel Hill scheduled to be added to the lab during the summer, and Duke has plans to bring another one in the fall. The University of Maryland and the National Institute of Standards and Technology may add a detector, and Tech has its own plans for another detector this summer.

Despite repeated attempts and analogies to give a layperson a description of the research, Volegaar's explanations often become tangled in terms such as "double-beta decays" and explanation of interactions of anti particles, neutrino "flavors" and "time-reversal symmetry."

When asked again to explain why scientists are doing this research, he gave a simpler answer.

"It's pretty cool to know how the sun works," he said.