LHC: Cooler Than Outer Space

The LHC has just passed a major milestone, by cooling one eighth of the machine to 1.9 K. Given that the temperature of outer space is about 3 K (the temperature of the cosmic microwavve background radiation), that makes the LHC very very cool indeed. The cold sector is 3.3 km long, and has over 200 of the big 2-in-1 superconducting dipole magnets in it. These are the magnets that will keep the particles going in a circle 27 km in circumference. This cooling operation has taken several months, starting in January, with many successful checks and tests along the way. Bravo!