From Sanford Underground Research Facility: “LBNF completes upgrade to Far Site’s underground ventilation system”

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From Sanford Underground Research Facility

Homestake Mining Company

Upgrades to the Oro Hondo Fan undertaken in preparation for LBNF construction and, ultimately, DUNE science.

September 27, 2019
Erin Broberg

A crane lowers the prefabricated E-House containing the new Variable Frequency Drive onto a concrete slab near the Oro Hondo Shaft along Kirk Road, with the Sanford Underground Research Facility’s Ross Headframe in the background. Photo courtesy Joshua Willhite, Fermilab

Several projects are underway at Sanford Underground Research Facility (Sanford Lab) to improve the reliability of the facility’s infrastructure. Crews are improving the facility for its role as the Far Site for Fermi National Accelerator Laboratory’s Long Baseline Neutrino Facility (LBNF) , which will house the largest physics experiment on United States soil: The Deep Underground Neutrino Experiment (DUNE) [below].

The LBNF project recently completed an upgrade of the Oro Hondo Fan, replacing its variable frequency drive (VFD). The Oro Hondo Fan is the main ventilation fan for the underground facility and is located on the surface along Kirk Road near Lead. This upgrade, completed with the support of Sanford Lab and four local contractors, ensures dependable ventilation in the underground spaces at Sanford Lab.

“This project puts a modern, reliable VFD in control of the Oro Hondo Fan’s motor,” said Mike Headley, executive director of Sanford Lab.

The project included the removal of the former VFD and the stick-built structure that housed it. These were replaced by a prefabricated Electrical House (E-House) and VFD, specifically designed for use at the Oro Hondo Shaft.

This prefabricated E-House contains a new Variable Frequency Drive which will control power to the Oro Hondo Fan. This is the primary fan for underground ventilation at the Sanford Underground Research Facility, the Far Site for the Long Baseline Neutrino Facility (LBNF), which will house the Deep Underground Neutrino Experiment (DUNE). Photo courtesy Joshua Willhite, Fermilab

At Sanford Lab, air comes underground via the Yates and Ross Shafts and is drawn horizontally and vertically through a matrix of underground passageways or drifts. The air current is then drawn up to the surface through the two exhaust shafts, the Oro Hondo Shaft and #5 Shaft. When exhaust fans spin in the Oro Hondo Shaft and #5 Shaft, they draw fresh air through this underground circuit.

As the main exhaust shaft for Sanford Lab’s underground ventilation system, the Oro Hondo Shaft’s fan is responsible for most of the underground’s fresh air current. The new VFD is connected to a 3,000 horsepower AC motor and will draw an average of 220,000 cubic feet of fresh air per minute through the Oro Hondo Shaft alone.

Josh Willhite, Fermilab’s LBNF conventional facilities manager for the work in South Dakota, explained that this upgrade increases the reliability of the underground ventilation system; such dependability is critical for future LBNF excavation and construction, as well as DUNE science.

“With the use of diesel-powered excavation equipment, followed by world class science underground, we need to make sure there is no preventable disruption to airflow or to our work,” said Willhite.

“Other experiments will benefit from this upgrade as well as it pulls in more fresh air through these ventilation systems,” said Headley.

Local contractors, including Border States Electric, RCS Construction, Muth Electric and Elite Industrial, participated in the upgrade project.

“As is always the case when coordinating these efforts with Sanford Lab, the coordination and integration of all parties has been very good,” said Willhite.

DUNE, which is hosted by Fermilab, will consist of two neutrino detectors placed in the world’s most intense neutrino beam. One detector will record particle interactions near the source of the beam, at Fermilab in Batavia, Illinois.

FNAL DUNE Near Detector

A second, much larger, detector will be installed more than a kilometer underground at Sanford Lab—1,300 kilometers downstream of the source. These detectors will enable scientists to search for new subatomic phenomena and potentially transform our understanding of neutrinos and their role in the universe.

The Long-Baseline Neutrino Facility will provide the neutrino beamline and the infrastructure that will support the DUNE detectors. Funding for the LBNF construction prep work comes from the Department of Energy Office of Science.

See the full article here .

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About us.
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.

LBNL LZ project at SURF, Lead, SD, USA, will replace LUX at SURF

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.

LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
“LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—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 will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

FNAL LBNE/DUNE from FNAL to SURF, Lead, South Dakota, USA


U Washington Majorana Demonstrator Experiment at SURF

The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.


CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”