The coldest ever hunt for dark matter has begun deep underground
Two kilometres underground near Sudbury, Ont., a machine has reached a temperature so low it barely seems real. Inside SNOLAB, scientists have cooled the Super Cryogenic Dark Matter Search, or SuperCDMS, to just tens of milliKelvin above absolute zero, roughly a hundred times colder than outer space. That number matters because the experiment’s detectors cannot truly come alive until they reach it. “Reaching this base temperature now allows us to turn on the detectors, make sure they are all working and start collecting data that potentially is coming from dark matter particles hitting our detectors,” says Miriam Diamond, a co-principal investigator in the international collaboration and an assistant professor in the University of Toronto’s department of physics in the Faculty of Arts & Science. For the team behind SuperCDMS, hitting base temperature marks a turning point. The project is no longer mainly about construction and installation. It is moving into commissioning and, soon after that, science operations. Scientists have reached a critical milestone in their efforts to detect dark matter – the mysterious substance that …





