The LZ dark matter experiment will operate at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. SURF is located at the former Homestake gold mine and has laboratory spaces nearly a mile underground. SURF hosts a number of scientific experiments that require underground operation in order to reduce the cosmic ray background.
LZ will be installed in the Davis Laboratory 4,850 ft underground (nearly a mile). This is the same site that housed Ray Davis’ Nobel Prize-winning neutrino experiment. The laboratory was occupied by the LUX experiment until 2016.
LZ will be housed in an 8 meter diameter by 6 meter high water shield containing 70,000 gallons of purified water. The water shield reduces external background signals to the detector, in particular neutrons and gammas. The water shield will also be instrumented with photomultiplier tubes to detect the Čerenkov radiation from cosmic muons.