Hunting WIMPs in the Black Hills - Webcast
"Deep Science" lecture series recorded live at the Pierre Ramkota Amphitheater 2. Tuesday, Jan.26, 2009, 7 p.m.
Two physicists leading a hunt for one of nature's most mysterious substances -- dark matter -- will discuss their experiment Tuesday evening during a free public lecture in Pierre.
Dr. Rick Gaitskell of Brown University and Dr. Tom Shutt of Case Western Reserve University are installing a dark-matter detector 4,850 feet deep underground in the Sanford Underground Laboratory at Homestake in Lead. "We need the unique opportunity this facility gives us," Dr. Gaitskell said. "This tremendous depth -- all those 4,850 feet." The Sanford Lab's depth will shield the sensitive dark-matter experiment from background cosmic radiation.
So far, no one has detected a "weakly interacting massive particle," or WIMP, which is a leading candidate for dark matter. "It's truly one of the great challenges of the early 21st Century," Dr. Gaitskell says.
Last month, in fact, dark matter made headlines around the world when researchers announced they had discovered a possible hint of the substance in an experiment deep in a former iron mine in northern Minnesota, but those results were inconclusive. Dr. Gaitskell and Dr. Shutt previously worked on that Minnesota experiment. Now they've assembled a team of scientists and engineers from nine universities and two national laboratories to build a different kind experiment.* It's called the Large Underground Xenon detector, or LUX, and it will be the most sensitive dark-matter detector of its kind ever built.
Dr. Shutt said that if WIMPs exist, we should be able to detect them on earth -- if the detector is sensitive enough. "Some 30 percent of the universe is in the form of a dark matter fundamentally different from ordinary matter," Dr. Shutt says. "Weakly Interacting Massive Particles, or WIMPs, created in the big bang, are one of the most promising ideas for what this dark matter could be."
"Hunting WIMPs in the Black Hills" -- is for general audiences, and especially for students. The Sanford Lab's "Deep Science for Everyone" lecture series already has introduced more than 3,000 South Dakotans to some of the world's top scientists, and Dr. Gaitskell already is doing outreach on his own. During a recent day of skiing at Terry Peak, near Lead, he found himself giving a chairlift talk about dark matter to some young students. "These were snowboarders," Dr. Gaitskell said. "Fourteen-year-olds. And when they said 'Cool!' I really think they meant it. You could see something switching on inside them."
The LUX dark-matter detector will be the first major physics experiment at the Sanford Lab. The South Dakota Science and Technology Authority is re-opening Homestake to a depth of 4,850 feet, but the former gold mine has shafts and tunnels as deep as 8,000 feet underground. The National Science Foundation is considering an even bigger proposal to make Sanford Lab at Homestake a national lab -- the Deep Underground Science and Engineering Laboratory, or DUSEL (pronounced "DOO-suhl."). A Homestake DUSEL would be the largest, deepest underground laboratory in the world, with experiments in physics, geology and biology.
More information at SanfordLab.org