| Rounds welcomes first dark matter experiment to Sanford Lab |
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| Written by Wendy Pitlick |
| Thursday, 17 December 2009 |
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LEAD Within days of flipping the switch to turn on the first dark matter experiment in the Sanford Lab, South Dakota will have already surpassed any previous or existing dark matter searches around the world.
That’s what Dr. Rick Gaitskell, principal investigator for the Large Underground Xenon (LUX) experiment told Gov. Mike Rounds Tuesday morning. The governor, as well as a group of media and Sanford Lab personnel, had gathered in a shipping warehouse on the surface of the Sanford Lab, where scientists are diligently working to assemble their experiment that will directly detect a substance that physicists around the world believe make up more than 90 percent of the universe, but that has been undetected — dark matter. The experiment, which is slated to be deployed to the Davis Cavern 4,850 feet underground in the former Homestake Gold Mine in the summer of 2010, is being assembled on the surface so scientists can test their instruments first. Such instruments include extremely sensitive photon detectors, a 50-ton vat of water, and a large, multi-story high detector filled with about 1,400 pounds of liquid xenon. Within a few months, Gaitskell told the governor scientists will have assembled their liquid xenon detector within an ultra-clean environment in the warehouse, before carefully lowering it four stories down into the massive water tank for its first integrated test. The only thing different from the surface test to the actual experiment underground, Gaitskell said, is the underground water shield will be about 250 tons, and the underground experiment will include the necessary 4,850 feet of rock above it to effectively shield the detector from naturally occurring cosmic rays on the surface. The detector operates under the theory that if dark matter particles interact with the liquid xenon they will produce a small flash of light that can be detected through the transparent element. That light flash will be detected by a series of ultra-sensitive photo multiplier tubes that are arranged above and below the xenon. Gaitskell said there are multiple active dark matter experiments around the world in at least 10 different national laboratories — including one at the much publicized CERN laboratory in Switzerland. However, the sheer size of the LUX detector and the ideal conditions which the Sanford Lab present make this experiment well ahead of the curve for the race to find the elusive particles that comprise most of the matter in the universe. “Within days of lowering this detector into the water tank in the Davis lab underground, and within days of switching it on and starting the dark matter search, we will have surpassed any previous dark matter search that has ever been done,” Gaitskell told the governor on Tuesday. “So we will be in discovery mode and the Sanford Lab will be the first laboratory to discover dark matter particles. That will be very significant.” Unlike the science that is occurring at the CERN laboratory, where scientists are attempting to manufacture dark matter particles, Gaitskell said the LUX experiment is designed to directly detect the particles that have existed since the beginning of time. “With all the investment that we have made here at the Sanford Lab we have been able to make a very significant leap in terms of the scale of dark matter instruments,” Gaitskell said. “What we are looking at here will be the most sensitive dark matter detector to be built. The state of South Dakota right now is actually in a race with the people of Switzerland, with international collaborations there, who are trying to directly create dark matter particles in their particle accelerator. To get there first we will be able to see these dark matter particles that came directly from the big bang. We are using the universe as our particle accelerator.” The search for dark matter and the likelihood of finding it in the former Homestake Gold Mine carry significant implications, Gaitskell and the governor stressed Tuesday. The dark matter search, Gaitskell said, is one of the key challenges of the 21st Century as it will allow scientists to better understand what the universe is made of. Additionally, Rounds said it means the state will gain notoriety as a place where cutting edge science occurs. “It means catching the attention and the imagination of not only other scientists but future students as well,” Rounds said. “So what this brings to South Dakota is the opportunity to keep young people in the state to do applied science, but also to do pure science. The search for dark matter is a pure science objective today. But when you find it, and it will be found and someone will have developed the techniques, those technologies can be used for other types of research efforts. The individuals, the graduate students, the scientists that are here will be in high demand to pursue and advance that kind of technology. If that occurs in South Dakota then that means that new job opportunities also occur in South Dakota and it means that new technologies will be developed, new ideas can be brought forth. That means new economic activity within the state. “But you start with the pure science. Here, in the central part of North America, 4,850 feet underground is what we think is the perfect location to actually be able to identify dark matter.” Further, Rounds went on to explain that Lead already has one of the largest man-made structures in the world, which is what exponentially increases scientists chances of making these leading discoveries. “So, after a century of digging and a century of building the structure, let’s not let it go to waste,” Rounds said. “Let’s put people to work in it. (It is) just like a skyscraper that goes down instead of up. Can you imagine all of the dozens of different offices that can be created deep underground rather than above ground in a skyscraper? Think of the possibilities, and they are all interactive. Think of what happens when you get scientists who are working on different types of experiments suddenly coming together and adding up all of the sources of knowledge that they have, some of their own knowledge and bringing it together to come up with new ideas and new ventures. That’s what happens at a national laboratory. This opportunity to grow, it doesn’t go away, but you have to get started first.” As scientists from around the country gather in Lead to assemble their LUX detector on the surface, Gaitskell said they have also been working to educate the public about their experiment. Whether they are speaking with the engineering staff of the Sanford Lab about their needs, or reaching out to middle and high school students, Gaitskell said he has been enthusiastically seeking those opportunities for community outreach. Even while skiing, last Saturday, Gaitskell said the response he got from a host of young people was encouraging. “Every chairlift I took up I was able to have a conversation where people were incredibly keen to understand,” he said. “I think when they said ‘hey cool,’ I think they really meant it. In a period of seven minutes they were extremely ready to try to understand and you could see something switching on and they were extremely pleased when they left that that science was taking place just five miles from the ski slopes they were on. Overall, Gaitskell thanked the state of South Dakota, and everyone involved in creating the Sanford Lab — including philanthropist T. Denny Sanford who donated $50 million to the lab project — for believing in his science. “I think the key thing to understand is that we have been fairly bold here at the Sanford Lab,” Gaitskell said. “This instrument is one that really does give us a shot to leap well beyond existing scientific dark matter experiments into an entirely new regime. In a sense, because what we have here is an entirely new laboratory, we have been able to take the vision of the governor and the people here at the Sanford Lab and create an ideal environment with a scale of engineering that lends itself to this large, very sensitive dark matter detector. We are not just doing trailing science. This is leading science. We are now standing in a laboratory that is giving us every opportunity to be the lab and the state that discovers the dark matter particle.” |
