Scientists hope to strike gold in the Black Hills Goal of Sanford lab is to unlock secrets of universe By David Lias
Plain Talk Simply put, scientists hope to strike gold in the former Homestake Mine at Lead once again. Thatâ�?�?s according to Jose Alonso, Ph.D, director of the Sanford Underground Laboratory at Homestake. He spoke before a capacity crowd at The University of South Dakota Thursday, Nov. 20, and described how scientists plan to transform the mine into a state-of-the-art underground laboratory. They wonâ�?�?t be searching for a rare metal, however. They hope to, in terms that seem to be lifted from the script of an old Star Trek television show, learn why the universe is made up of matter rather than anti-matter. The characteristics of the former mine are perfect for allowing physicists and other scientists to unlock some of the deepest secrets of the universe â�?�? secrets that can only be detected while being shielded from the cosmic rays that are constantly bathing the earth by the sun. â�?�?The process started in the year 2000, and itâ�?�?s been a long, arduous process to get to where we are now,â�? Alonso said. â�?�?In April 2006, the entire mine was actually donated to the state, and in June 2006, Denny Sanford announced a $70 million gift to the laboratory.â�? The Sanford Laboratory will host a broad range of experiments at several levels of the former gold mine in Lead, from the surface to 4,850 feet underground. Several years ago, Dr. Ray Davis of Brookhaven National Laboratory built a solar-neutrino detector at the 4,850-foot level in Homestake, and in 2002 he was awarded the Nobel Prize for discoveries that changed the course of physics. A new â�?�?dark matterâ�? experiment already is planned for the Davis Cavern. Alonso noted that besides Sanfordâ�?�?s $70 million gift, funding for the Sanford Underground Laboratory includes a $10 million federal HUD grant, and $35 million from the South Dakota Legislature. Sanford designated $20 million of his gift for a Sanford Science Education Center at the Homestake surface campus. On July 10, 2007, the NSF named Homestake the site for a proposed DUSEL (Deep Underground Science and Engineering Laboratory), which would include labs and other facilities on the surface and throughout the mine â�?�? to a depth of 8,000 feet or even deeper. This development places South Dakota in steps with cutting-edge â�?�?deepâ�? science thatâ�?�?s currently going on in locations numerous locations in the United States, Canada, Europe and Japan. The need to go deep â�?�? and long â�?�?With Homestake, we will be doubling the amount of underground laboratory space,â�? Alonso said. â�?�?The ability to set up scientific experiments at levels of 4,850 feet below the surface and deeper practically eliminates all cosmic ray flux.â�? Homestake provides 380 miles of drifts and tunnels underground, with underground shafts and large caverns that already exist. â�?�?We will be building a main campus at the 4,850 foot level, and a another major cavern at the 7,400 level will also be utilized,â�? he said. A number of scientific investigations require an underground environment â�?�? the deeper the better. Alonso noted that there are questions important to the fields of astrophysics and physics that cannot be answered unless experiments are shielded from cosmic rays and other background radiation by thousands of feet of rock. Homestake is the deepest mine in the United States, reaching a depth of more than 8,000 feet. With over 375 miles of existing tunnels, it is ideally suited for conversion into a scientific research facility. â�?�?The Homestake mine is a vast site capable of hosting a comprehensive suite of experiments in all major fields of science, including low background physics experiments and particle and nuclear physics experiments that require very large detectors,â�? Lesko said. â�?�?The site can simultaneously host multidisciplinary deep sub-surface studies in geosciences, geoengineering and microbiology.â�? The Homestake proposal calls for two major deep underground facility levels. One level will serve research operating from the surface on down to 4,850 feet. Construction of the â�?�?Laboratory at 4850â�? will entail modification of an existing scientific site and preparation of new experimental chambers. The other facility is planned for the 7,400 foot depth level. A large network of existing caverns, drifts, ramps and boreholes will serve as the basis for the future construction of this second level over the next 30 years. â�?�?Our plans also include a near surface facility with drive-in access for experiments that require only modest shielding,â�? Lesko said. â�?�?In addition, potential users have requested access to depth levels at 2,000, 4,100 and 8,000 feet. Our task is to tailor the Homestake site for science access and reduce its foot-print to only the areas of greatest scientific interest.â�? Prominent among the experiments that require the ultra-low backgrounds realized at great depths are studies of the elusive, ghostlike sub-atomic particles known as neutrinos. In recent years, experiments at other underground neutrino laboratories have confirmed that the neutrino, once thought to be a massless particle, does indeed have a small amount of mass, and that the three families of neutrinos transform, or oscillate, between families. Like all great discoveries, this finding has raised new questions. A next generation of neutrino experiments at the much greater depths of Homestake should help provide answers. â�?�?For example, detection of neutrinoless double beta decay, which can be done at Homestakeâ�?�?s SUSEL, is the only way to determine whether neutrinos are their own anti-particle,â�? said Lesko. A thousand-mile long beam Fermilab has had limited success with its current lab work, which includes shooting particles from an accelerator located in central Illinois to an underground facility 200 miles away in Minnesota. The plan with Homestakeâ�?�?s DUSEL, he said, is to â�?�?beef upâ�? that neutrino beam. The higher intensity stream of particles will be sent from Illinois all the way to Homestake. â�?�?At Homestake, the plan is place a very large neutrino detector under the ground,â�? Lesko said. â�?�?This experiment is the very highest priority of any experiment to be done in high energy physics. Think about that.â�? The detector to be placed under the nearly a mile underground at Homestake will be one of the largest ever built, with a total capacity of a million tons. To fully understand the neutrino, Lesko said beams of particles originating from Fermilab, outside of Chicago, can be sent through nearly a thousand miles of rock to the Homestake detectors. These detectors will search for evidence of a rare physical process, known as â�?�?leptonic CP violation,â�? that may help explain why the universe is dominated by matter rather than anti-matter. â�?�?These same detectors could also be used to search for nucleon decay, a long-sought signal of Grand Unified Theories,â�? Lesko said. Other astrophysical research planned for SUSEL include studies of nuclear astrophysics, future generation gravity wave detectors, geoneutrino and solar neutrino experiments. Scientists at SUSEL will also get a closer than ever look at the earthâ�?�?s crust and new opportunities for monitoring the movement of groundwater. In addition, they will be able to examine the unique biochemistry of organisms that thrive under heat and pressure conditions which would be deadly to surface dwellers. Carbon sequestration efforts â�?�? the idea of safely burying global warming gases like carbon dioxide underground â�?�? should also receive a significant boost. Added Lesko, â�?�?Experiments at SUSEL will also open entire new avenues for basic engineering studies that could extend our understanding of rock properties, create and stabilize future excavations, and develop new technologies and techniques to create safer underground environments,â�?�? Lesko said. Science is already underway The NSF awarded the University of California at Berkeley $5 million a year for the next three years to develop a technical design for the laboratory. A group of scientists called the Homestake Collaboration is developing the proposal, led by principal investigator Dr. Kevin Lesko, who is a physicist at Berkeley, and by co-principal investigator Dr. Bill Roggenthen of the South Dakota School of Mines & Technology. A DUSEL at Homestake would cost about $550 million, half of which would be used to develop scientific instrumentation at the lab. DUSEL construction, which likely could not begin until fiscal 2012, will need the final approval of the NSF, the National Science Board, Congress and the White House. â�?�?Our goal is that the National Science Foundation will have all of the goal material ready and seen, and we will be presenting to the National Science Board, which is the governing the board of the National Science Foundation, in the spring of 2010, and the project will be approved,â�? Alonso said. â�?�?This become a major milestone. It opens the possibility to be receiving federal funding.â�? Even if funding approval is granted in 2010, he added, itâ�?�?s likely that it wonâ�?�?t be available until fiscal year 2013. Construction will likely begin that year, Alonso said, and will take four years to complete. Very large mega-caverns that will be required to house of the major components of the lab wonâ�?�?t be completed until 2015. There are challenges that must be overcome. The bottom 4,000 feet of the mine is filled with water, because when Homestake Mine was closed, pumping stopped. The pumping process is underway once again, and removing all of the water likely will take several years. There are several projects that are presently underway, however, including activities involving students, teachers and researchers from the university. Hydrologists are at work various levels in the mine, and biologists are exploring the mineâ�?�?s shafts. â�?�?We found this extremely interesting fungus deposit at the 2,000-foot level, and we asked Cynthia Anderson, who is a professor at Black Hills State, if she would like to come take a look at it, and she replied, â�?�?Yeah!â�?�? â�?�? Prior to being named director of the Sanford Underground Laboratory at Homestake last October, Alonso spent three decades at the Lawrence Berkeley National Laboratory in California. For most of his career, Alonso worked with particle accelerators, including medical and security applications. He directed the Bevalac accelerator at Lawrence Berkeley conducting research into the relativistic heavy ions used in nuclear science and radiation therapy. Alonso earned his Ph.D. in nuclear physics at the Massachusetts Institute of Technology as well as research at Yale University before joining the Lawrence Berkeley National Laboratory. â�?�?Itâ�?�?s long-term, and there is a tremendous amount of effort that has to go into this, but I think there is real gold at the end of the rainbow,â�? he said. �?