LEAD | Renovation is to begin this week to the Sanford Underground Research Facility’s Davis Cavern, in preparation for installation of the next generation of dark matter experiment at the site of the former Homestake Gold Mine in Lead.
The cavern which housed the experiment known as Large Underground Xenon, or LUX, from 2012-2016, will be rebuilt to pave the way for installation of LZ, or LUX-ZEPLIN.
“Planning for this renovation started several years ago—even before LUX was built,” said John Keefner, underground operations engineer at the lab, in a release. “Now, we’re finally at the point where we can begin to refit the cavern and existing infrastructure to allow for the installation of LZ.”
LZ, a second-generation dark matter experiment, replaces LUX, which was named the most sensitive of its kind in 2013. LZ will hold 10 tons of liquid xenon, making it approximately 30 times larger and 100 times more sensitive than its smaller cousin.
The Davis Cavern renovation project includes removing an existing cleanroom, tearing down a wall between two former low-background counting rooms, installing a new hoist system, building a work deck and modifying the water tank itself to accommodate the larger cryostat. Additionally, renovations include a radon reduction room and a xenon storage room.
But just on the other side of the Davis Cavern, through a double door, is the common corridor—and the entrance to the Majorana Demonstrator Project, an incredibly sensitive experiment that requires an extremely clean environment.
“We’re setting up a dividing line between the existing science space and the construction zone,” Keefner said. “We’ve taken several precautions to ensure dust and other particulates can’t get into the Majorana cleanroom.”
Some of those measure include putting up tents at the door between the Davis Cavern and common corridor. Additionally, construction crews will enter the Davis Cavern through the decline drift—the same drift Ray Davis would have used to reach his solar neutrino experiment, which ran for nearly 30 years in the Davis Cavern.
When all renovations are complete, including updates to plumbing, electrical and ventilations systems, scientists will begin installing the experiment itself.
Contractor for the renovation is Ainsworth Benning of Spearfish, the same company that outfitted the entire Davis Campus beginning in 2010.