Particle smasher set for weekend startup,says CERN2 April
2015
A scientist walks in a tunnel inside the EuropeanOrganisation
for Nuclear Research (CERN) LargeHadron Collider during maintenance
works near Genevaon July 19, 2013
The world's biggest particle collider is set to restartthis
weekend after a two-year upgrade, theEuropean Organisation for
Nuclear Research(CERN) said Thursday.
Engineers at the Large Hadron Collider (LHC)hope to introduce
two proton beams, the sourcematerial for sub-atomic smashups, as
part of therecommissioning process.
"The first beams could be circulating in themachine sometime
between Saturday andMonday," CERN said in a statement.
"We are confident of being able to restart themachine over the
weekend, as all of the testsperformed so far have been successful,"
saidFrederick Bordry, CERN's director for acceleratorsand
technology.
A short-circuit in one of the LHC's magnet circuitslast Saturday
had delayed the eagerly-awaitedrestart.
The LHC comprises a 27-kilometre (17-mile) ring-shaped tunnel
straddling the Franco-Swiss border,in which two beams of protons
are sent in oppositedirections.
Powerful magnets bend the beams so that theycollide at points
around the track where fourlaboratories have batteries of sensors
to monitorthe smashups.
The sub-atomic rubble is then scrutinised for novelparticles and
the forces that hold them together.
In 2012, the LHC discovered the Higgs Boson, theparticle that
confers mass, earning the Nobel prizefor two of the scientists who,
back in 1964, hadtheorised its existence.
Since then, the giant machine has been undergoingan upgrade to
beef up its maximum collisioncapacity from eight teraelectronvolts
(TeV) to 14TeVseven TeV for each of the two
counter-rotatingbeams.
The startup work will see engineers attempt toinject two beams
into the tunnel at a lower energyof 450 gigaelectronvolts, but
there will not becollisions.
If all goes well, "particle collisions at an energy of13 TeV
could start as early as June," CERN said.
During the next phase of the LHC programme,researchers will
probe a conceptual frontier callednew physics, with enigmatic "dark
matter" the bigarea of interest.
Ordinary, visible matter comprises only about fourpercent of the
known Universe.
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