The Large Hadron Collider (LHC) performed extremely well in 2011 and now engineers at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland, want to crank up the juice through 2012.
However, to avoid a similar incident to the devastating “quench” that buckled a section of the LHC’s supercooled magnets in 2008 — thereby delaying the LHC’s official start up by over a year — they are going to do it very carefully.
Currently, the 17-mile (27-kilometer) ring of superconducting magnets under the Swiss-French border is firing protons together at approximately half the energy the LHC was designed to achieve.
Now, CERN has announced their decision to give the speeding protons an extra boost this year by increasing the collision energy by 1 Teraelectron volt (TeV) to a record-breaking 8 TeV. This small amplification may seem conservative considering the LHC is designed to be pushed to 14 TeV, but when living on the leading edge of physics discovery, it pays to be cautious.
The 2008 quench cost CERN dearly. Due to a faulty electrical connection between two of the magnets used to “steer” protons traveling close to the speed of light, vacuum conditions inside the magnets were lost, culminating in six tons of liquid helium being dumped into the tunnel and severe damage to dozens of supercooled magnets. If this were to happen again due to some unforeseen weakness in the superconducting ring of magnets, it would be a devastating blow for an otherwise flawless three years of LHC operations.
And if the LHC were to break in 2012, it would hurt the continuing hunt for the Higgs boson just at a time when tantalizing hints of a Higgs signal are beginning to show.
The Higgs boson is a long-theorized subatomic particle that is thought to endow all stuff in the Universe with mass. It is the cornerstone of modern physics — if the Higgs doesn’t exist, some fundamental physical theories would have to be rewritten. So, in an effort to answer one of the biggest questions mankind has ever pondered, the most powerful particle accelerator needed to be built.
When colliding protons head-on in the LHC, the conditions last seen just after the Big Bang can be created for the briefest of moments. By focusing the LHC’s “proton beam”, more collisions are possible; by increasing its energy, more primordial particles that constitute all the matter in the Universe are created. The LHC is very adept at focusing the beams as well as cranking up the collision energy.
And now, LHC physicists may be catching a glimpse of a Higgs signal coming from the guts of one of the cathedral-like particle detectors positioned at strategic points in the LHC’s magnet ring.
By analyzing proton collision data from the Compact Muon Solenoid (CMS) detector, physicists have been able to increase their certainty that the faint signal — or “bump” in the datasets — may be due to the existence of the Higgs boson. Unofficially, the CMS group have been able to boost their certainty from 2.5 sigma to 3.1 sigma. When combined with data from the ATLAS detector, the overall certainty rises to 4.3 sigma. In this game of statistical probability, 4.3 sigma means there is a 99.996 percent chance that this signal is real.
But keep that Champagne corked for now, this is not a Higgs discovery! Generally speaking, a 5 sigma result is considered the “Gold Standard,” so more collisions are needed and more data needs to be collected.
Fortunately, with this boost in energy and continued experiments through 2012, more collision events will improve the resolution of this Higgs “bump” (if it exists) and we may not be far from the announcement we’ve all been waiting for.
Image: The massive CMS detector in the LHC (CERN/LHC/CMS)