By Wendy Pitlick
LEAD, S.D. (AP) – Scientists with the Long Baseline Neutrino Experiment have received the Department of Energy’s approval to move forward with designs for a $50 million building that will
eventually house a $250 million detector, and supporting infrastructure to be constructed in Kirk Canyon, for the first phase of what is expected to be an $867 million project.
The multi-phased project will have scientists shooting a beam of neutrinos from Fermilab, near Chicago, to a specially constructed site in Kirk Canyon in Lead, where a neutrino detector will help scientists do preliminary studies about the properties of the subatomic particles.
Eventually scientists hope to move the experiment 4,850 feet underground in the Sanford Lab, but federal budget restraints called for scientists to present a more phased approach and initially plan for a surface deployment. On Dec. 10 the U.S. Department of Energy gave the green light for LBNE scientists to move forward and develop designs to build that first phase, which includes a detector filled with 10 kilotons of liquid Argon that will be strategically placed on Sanford Lab and Barrick property in order to study neutrinos that are being sent from Fermilab.
The detector will be near the Oro Hondo fan in Kirk Canyon, and will overlap onto Barrick property near Grizzly Gulch. Willhite said Barrick has agreed to donate the property for the experiment, but officials are still working out the legal bugs for the exchange.
Kevin Lesko, the Head of the Berkeley Operations Office for the Sanford Underground Research Facility, said the total cost of making upgrades at Fermilab and building the surface lab detector in Kirk Canyon for LBNE will be about $867 million over the course of 10 years. To move the experiment to the 4,850 feet level of the Sanford Lab would cost significantly more, and scientists with the LBNE collaboration are actively seeking international partners and other funding sources to help offset the cost.
Joshua Willhite, the conventional facilities far site manager for the LBNE detector in Lead, said current plans in Lead are to build a nearly $50 million building and supporting infrastructure. Current designs call for creating new access from Kirk Road that goes up to above Grizzly Gulch, and to dig a pit more than 60 feet up the hill into the hillside, and down to 60 feet deep.
Then, Willhite said the material from that excavation will be piled on the roof of the building – about 35 feet deep at the deepest point – to create more shielding for the detector. Three massive, 10 feet thick concrete walls, will provide even more cosmic ray shielding for the detector.
“We’re basically building a dam to hold this cryostat in place,” Willhite said.
Heating systems will be installed in the concrete walls surrounding the detector, to keep the surrounding rock from freezing. The neutrino detector itself will be cooled to 170 Kelvin (-153 degrees Fahrenheit).
Now that the LBNE has achieved federal approval and funding for the design work is on its way, Willhite said crews are actually working ahead of schedule to get the project going. LBNE scientists hosted representatives from about 18 different excavation contractors at the site, and by the middle of the year they plan to do a geotechnical investigation of the site.
Once that is completed, he said they will go into a preliminary design for excavation, infrastructure and building, a process that will take a little over a year.
Then, the final design stage will take about a year. LBNE scientists hope to be able to start constructing their facility by April 2017. By 2020 they hope to start moving their experiment in to the Kirk Canyon site, and by 2022 they hope to be taking data.
Willhite said the surface facility is being constructed with an eye towards moving the experiment underground. The neutrino beam from Fermilab is pointed at the surface site in Kirk Canyon. But once scientists move the experiment underground they will still be in line with the beam.
“When the beam leaves Fermilab it is about the size of a pencil,” said Willhite. “But by the time it gets here it is about 2 feet deep. The nice thing about that is because it is pointed at us, when we decide to go underground the beamline is already set.”