Cern atom collider to restart with a bang after upgrade

The world's biggest atom smasher is to restart today after two years of repairs and improvements, and needless to say it will start with a bang.

The intensive upgrade required one million hours of work, the object being to allow the Large Hadron Collider to reach record energy levels.

When it last ran at the end of 2012 it was reaching energy levels of four trillion electron volts – a measure of collision energy. The new run which gets under way in Switzerland at 6am Irish time on Wednesday will push energy levels to 6.5 TeV.

That is only the half of it.The collider sends two separate beams of particles racing around its 27km circumference until they are moving almost as fast as light.

These beams are then pushed by giant superconducting magnets so they cross, causing collisions at stupendous energies. The combined energy reaches up to 13 TeV and all of this record-breaking energy is focused down to a pinpoint of collision just one atom wide.

The idea is to break the particle down into its elemental parts. This causes the release of many smaller short-lived particles that teach scientists about the structure of matter and how the universe formed.

Energies at this level have not been seen since the formation of the universe in the Big Bang. The collider has a collection of experiments that can detect any particles that are kicked out, and this data is what scientists are after.

"We will be in uncharted territories and you never know for sure what you are going to find," says Prof Ronan McNulty of University College Dublin.

The big jump in energy levels will deliver new information, he says. "We honestly can't be certain what we are going to find. What we hope to find are things that tell us about dark matter and dark energy. It is like having a time machine that can bring us closer to the origins of the universe."

UCD has an experimental group, including Prof McNulty, who conducts research, at Cern.