World's most sensitive dark matter detector tested for the first time

 

 Matthew Kapust/Sanford Underground Research Facility

The search for dark matter just got a firm pair of eyes. A test run of the LUX-ZEPLIN (LZ) detector in South Dakota has appears to be the most sensitive dark matter detector yet build, and researchers are getting ready to turn it on and start exploring in earnest. 

LZ contains a huge titanium tank filled with 10 tons of extremely pure liquid xenon. When a particle from outside the tank strikes a xenon atom, it forms a burst of light that is measured by a series of detectors surrounding the tank. The properties of that light can then be examined to determine what type of particle caused it. To protect the xenon from particles and radiation that we know don’t come from dark matter, the tank is surrounded by a massive tank of purified water and the whole thing is buried more than a kilometer underground in an ancient gold mine. 

“The center of LUX-ZEPLIN (LZ) is the 100% purest site on Earth, possibly in the solar system. There’s no other part of space on or on Earth that is that radiation and dust free ,” said by LZ teammate Chamkaur Ghag at University College London. “We can look after about only a gram of dust in the detector – just 3 grams of dust and we wouldn’t be able to observe anything.” 

Regardless of sensitivity, though, three months wasn’t lengthy enough to actually detect dark matter. Even if some did come through the detector during that time, we wouldn’t have enough information to say for sure what it was, says Ghag. 

 
“For now, it’s kind of a strange thing, we’re saying that we’re the finest in the world at finding nothing,” he says. “But the hope of discovering new physics a few years from now is entirely achievable.”