Cryogenic Dark Matter Search

The Cryogenic Dark Matter Search (CDMS) is a series of experiments designed to directly detect particle dark matter in the form of Weakly Interacting Massive Particles (or WIMPs). Using an array of semiconductor detectors at millikelvin temperatures, CDMS has at times set the most sensitive limits on the interactions of WIMP dark matter with terrestrial materials (as of 2018, CDMS limits are not the most sensitive). The first experiment, CDMS I, was run in a tunnel under Stanford University. It was followed by CDMS II experiment in the Soudan Mine. Next, SuperCDMS (or SuperCDMS Soudan), was located deep underground in the Soudan Mine in northern Minnesota and collected data from 2011 through 2015. The series of experiments continues with SuperCDMS SNOLAB, an experiment located at the SNOLAB facility near Sudbury, Ontario, in Canada that started construction in 2018 and began taking science data in August 2026.

Background

Observations of the large-scale structure of the universe show that matter is aggregated into very large structures that have not had time to form under the force of their own self-gravitation. It is generally believed that some form of missing mass is responsible for increasing the gravitational force at these scales, although this mass has not been directly observed. This is a problem; normal matter in space will heat up until it gives off light, so if this missing mass exists, it is generally assumed to be in a form that is not commonly observed on earth.

A number of proposed candidates for the missing mass have been put forward over time.