LHC cooled to operational temperatures

The Large Hadron Collider has now been completely recooled to its operating temperature, just two degrees above absolute zero

All sectors of the world's largest particle accelerator have now been cooled to operational temperatures of approximately -271°C.

The European Organisation for Nuclear Research, Cern, said on Friday that the final sector of the Large Hadron Collider (LHC) had reached 1.9K.

In a bulletin on Friday, Cern called this "an important step towards the final commissioning of the machine".

The LHC had to be decommissioned last September, after a fault in a copper splice in the machine led to an explosion. Cern said on Friday that splice resistance measurements had been taken in three of the LHC's eight sectors, and had all showed normal values. Tests on the remaining five sectors are taking place, and are expected to be completed by the end of October.

The eight sectors have been cooled individually over time. As three of the sectors were cooled to nominal operating temperatures, the magnets which guide and focus the beams of protons were powered up, said the bulletin.

At present, the three sectors have magnets powered at 2kA. Over the coming weeks, magnets in all eight sectors in the 27km LHC ring will gradually have current put through them, up to 6kA. This is the amount of energy needed to guide beams with a nominal energy of 3.5 TeV, or half the power envisaged for the LHC experiment, said the Cern bulletin.

Cern told ZDNet UK at the beginning of October that the LHC would probably be colliding beams by mid-November. The machine will be used to conduct experiments designed to examine the fundamental nature of matter.