It's tempting to imagine that turning the Large Hadron Collider at CERN on and off is as simple as Brian Cox donning a pair of safety specs, shouting "clear!" into a big tunnel and throwing one massive breaker switch.
It's a bit more complex than that. In fact restarting the LHC takes months of checks and tuning — not to mention upgrades, since the particle accelerator, when it is turned back on after a two-year hiatus, will be operating at twice the collision energy of the previous Higgs Boson-detecting run.
The reenergised instrument will be used this time around to try to stretch the boundaries of physics even further, with collisions up to 13 TeV in energy (that’s lots).
On its blog CERN reports the 27km machine is almost ready:
“The giant endcaps of the ATLAS detector are back in position and the wheels of the CMS detector are moving it back into its "closed" configuration. The huge red door of the ALICE experiment is closed up ready for restart, and the access door to the LHC tunnel is sealed with concrete blocks.”
The machine should be running again later this month.