A new detector has a clever way of detecting dark matter

Fermilab

A new dark matter detector has gone online today, using a rather clever method of searching for signs of rare interactions between dark and regular matter. The tool uses a liquid that's kept poised on the edge of boiling, such that even the tiniest bit of additional energy—say, caused by the impact of a dark matter particle—will create a bubble of vapor in the detector.

The new detector is called COUPP, for Chicagoland Observatory for Underground Particle Physics. Although it was organized by Fermilab outside of Chicago, the detector resides in Canada's SNOLAB, deep in a mine near Sudbury, Ontario. This location shields it from a lot of the background noise of particles that come from the atmosphere and radioactive substances.

The idea behind the detector is similar to that of the CDMS experiment. Most evidence points to dark matter being composed of WIMPS—weakly interacting massive particles. Although dark matter mostly interacts with other matter via gravity, in some models there's a chance that it can physically interact with regular matter, albeit very weakly. To search for these interactions, researchers must detect collisions that only impart a tiny bit of energy to a material.