There was a bit of a trick to the question, we admit. It is the LUX-ZEPLIN (LZ), a laboratory located 1.5 kilometers underground in an abandoned gold mine in the United States . It is the purest place on the planet.
It is located inside the Sanford Underground Research Center and is the world’s most sensitive detector of dark matter which is supposed to be the invisible glue that holds the universe together.
The search for dark matter, underground
The LUX-ZEPLIN (LZ) experiment, whose first run lasted more than three months and ended in April, found no signs of hypothetical bits of dark matter called weakly interacting massive particles (WIMPs) in space. WIMPs are thought to have formed naturally after the Big Bang and thus could provide an explanation for dark matter.
Despite the lack of hard data, the scientists confirmed that the US Department of Energy-led experiment is working as planned, leaving the possibility of finding dark matter in future rounds.
Why is it the purest place?
The first thing is that it is underground, isolated from dust and radiation (remember that cosmic rays constantly bombard our atmosphere). This increases its sensitivity and the chances of detecting signals.
Its design is oriented so that its interior captures even extremely weak signals, which could be dark matter particles. The second is a titanium tank filled with ultrapure liquid xenon : specifically, it is filled with 10 tons of this noble gas that can lead to very high levels of purification and, with it, purify most contaminants. If the experiment detects a burst of light , it will be detected by the LZ’s sensors.
So far, no luck.
Reference: The LZ Dark Matter Experiment
