Nanoelectric systems research. Physicists working on a dilution refrigerator. A dilution refrigerator is a cryogenic (extremely low temperatures) device that cools objects down using a mix of helium isotopes (atoms that have different numbers of particles in the nucleus). Here, the dilution refrigerator is used in cryogenic temperature experiments investigating the properties of nanoelectric systems. Photographed at the National Physical Laboratory in Teddington, UK.