May 06, 2015
Tom Hanson, KDLT News Anchor
The former Homestake Gold Mine in Lead closed in 2002. It is now the Sanford Underground Research Facility Funded by the state of South Dakota, the U.S. Department of Energy and a donation from T. Denny Sanford the lab is drawing some of the sharpest minds in science to South Dakota.
The search for dark matter and the study of neutrinos are at the heart of two of the underground labs biggest projects. The equipment used in this research is so sensitive it has to be shielded from cosmic rays on the earth’s surface.
Located almost a mile underground the LUX is a dark matter detector.
The two men behind the project Simon Fiorucci (left) and Harry Nelson are hunting something so rare, no one has ever seen it, in fact no one really knows exactly what it is.
“We are trying to detect a new form of matter which we are absolutely sure constitutes about 85 percent of the matter in the universe,” said Nelson. “And the fabulous thing is no one knows what it is. So there are a bunch of conjectures and so the gadget behind us is dedicated to the most popular conjecture of what this dark matter of the universe is.”
The gadget is the Large Underground Xenon Detector or LUX, a phone booth sized container holding liquid xenon, cooled to -160 degrees F and surrounded by thousands of gallons of specially treated water. And according to Sanford Underground Lab officials the LUX has the reputation as the most sensitive detector ever built. Nelson has a nack for taking a very complicated process and simplifying it.
“Our detector occasionally should see a little touch of the dark matter and it will make the atoms in our detector recoil and emit a little bit of light and also make a little bit of electric charge, that’s what we are trying to do here,” said Nelson.
But according to Fiorucci so far that hasn’t happened.
“We’ve seen nothing at all, which at first glance you might think well that’s not great, actually what that means is we’ve eliminated quite a number of possibilities, said Fiorucci.
Possibilities surround the other big project currently underway at the Sanford lab. The Majorana Demonstrator is looking at neutrinos.
Particles so small there are billions of them passing through your body as you read this story. Professor John Wilkerson and his team are searching for a rare form of radioactive decay.
“If we see this rare decay it would actually tell us that neutrinos can be their own anti particle and it might explain why we exist, why there’s so much matter and why there’s not anti-matter in the universe,” said Wilkerson.
The vast majority of the observable universe from our planet seems to be made of matter and not antimatter. Why? Is one of the most interesting questions facing scientists.
Building on the success of the LUX and Majorana Demonstrator, the next generations of projects are coming to the underground facility.
The LZ project will continue the search for dark matter and will be 30 times larger than the LUX.
However the Deep Underground Neutrino Experiment or DUNE will be the biggest of all.
The $1.5 billion project will try to find out how neutrinos change from point A to point B. It involves shooting neutrinos through the earth from Fermilab in Illinois to a huge detector at the Sanford Underground Lab.
The man in charge of the facility, executive director Brookings native Mike Headley says they are excited to be a part of the project.
“This will really be a big deal”, said Headley. “It’s an international collaboration that has close to 150 institutions worldwide and over 700 collaborators. The Long Base Neutrino Experiment (also called DUNE) is basically a $1.5 billion project. It is 1/3 funded international 2/3 funded in U.S. About 300 million of that $1.5 Billion will be facility construction here in South Dakota, so it’s going to be one of the biggest construction projects we’ve ever had in the state.”
Construction on DUNE will begin next year. Scientists behind the project say neutrinos could hold clues about how the universe began and why matter greatly outnumbers antimatter, allowing us to exist.
See the full article here.
The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.
The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.
Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.
In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.
In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.
The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s. In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.
Another major experiment, the Long Baseline Neutrino Experiment (LBNE) [being replaced by DUNE]—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE [DUNE] will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.