Large Hadron Collider resumes operations after refit

After two years of intense maintenance and consolidation, and several months of preparation for restart, the Large Hadron Collider (LHC), the most powerful particle accelerator in the world, is back in operation.

Following a two-week extension to a two-year upgrade, Europe's Large Hadron Collider particle accelerator started on Sunday at 10.41am in Geneva, a proton beam was back in the 27-kilometer ring, followed at 12.27pm by a second beam rotating in the opposite direction. These beams circulated at their injection energy of 450 GeV. Over the coming days, operators will check all systems before increasing energy of the beams.

The mammoth machine was shut for upgrades after the discovery of the Higgs boson in 2012 (See: CERN researchers say new particle discovered is Higgs boson). The upgrades would allow it to smash protons together at significantly higher energy.

The upgrades would also extend the ability of the collider to search for different varieties of Higgs boson-- sometimes referred to as the "God particle",  (Large Hadron Collider prepares to probe more mysteries of the universe).

The appellation "God particle" comes from its role as one of the basic cogs in the machinery of the universe, as also dark matter, supersymmetry and other mysteries of how the universe worked.

The facility built into an underground ring 27 km in circumference is operated by CERN, the European Center for Nuclear Research.  "Today, CERN's heart beats once more to the rhythm of the LHC," CERN director general Rolf Heuer said in a statement on Sunday.

CERN had been hoping to get the LHC to resume normal functioning two weeks ago, due to intermittent short-circuit problem those plans had been delayed.

Carrying out repairs on the machine could be difficult: its super-powerful electromagnets need extremely cold temperatures to work, but warming up a section of the ring to send in personnel was a long drawn affair.

Cooling the machine back down -- to its operating temperature of 1.9 degrees Celsius above absolute zero (minus 456 Fahrenheit) also was time consuming.

With the LHC getting ready for action, scientists are gearing up to embark on  a new mission that they hope could give bring them up close to the dark universe.

Scientists at the facility yesterday shot two particle beams through the colliders 16.8-mile tunnel, beneath the Swiss-French border near Geneva.

Scientists can look forward to nearly twice the energy and more violent particle crashes this time around with which they hope to see all sorts of new physics.

According to CERN, the restart went smoothly and faster than expected. Still, it would take some time for the accelerator to start working at full speed and particle.

Joerg Wenninger, the accelerator's coordinator of operations said it would take about six weeks to two months for the first stable collisions for the experiments, as they had to commission all the instruments, all the systems one by one, AP reported.