Despite a delay in the scheduled start of high-speed proton collisions in
the Large Hadron Collider—a particle accelerator operated by the European
Organization for Nuclear Research (CERN)—due to technical glitches, just
after 1 p.m. Central European Time (CET), the LHC set a world record, colliding
proton particle beams at 7 TeV for the first time in history. On a live Webcast documenting the event, CERN scientists
described the successful collisions as "beautiful,"
"fantastic" and "historic."
At approximately 12:30 p.m. CET, CERN’s
Twitter account announced the beams had accelerated up to 3.5 TeV and
operators were preparing to collide the beams. About half an hour later, it was
announced that for the first time in history, scientists collided two beams
traveling at that speed, setting a world record (though the Twitter feed
acknowledged nature does this all the time with cosmic rays and other high
energy). The achievement is a major accomplishment for the LHC and CERN, which
have both seen numerous setbacks on the road to eventual success. A live
Webcast of the event showed CERN scientists in the ATLAS control room erupting
into cheers and applause as the first successful collision occurred. The beams
were later successfully stabilized, drawing more applause, cheers and smiling
faces.
During the energy ramp-up to circulate beams at 7 TeV (3.5 TeV per beam), the
beams were lost due to the machine’s protection system. Andrzej Siemko, who
supervises the machine’s quench protection system, theorized an electric
perturbation, seen also by other accelerators, made the protection system stop
the magnets. CERN reported the machine was in the process of restarting.
According to a later tweet by CERN, new analysis showed that the magnetic
coupling of the main circuits in the Super Proton Synchrotron (SPS), used to
accelerate protons and antiprotons, electrons and positrons for use as the
injector for the LHC, caused the problem and not an electric perturbation. A
second attempt an hour later was unsuccessful, prompting scientists to “dump
it” and try for a new injection. "Major discoveries will happen only when
we are able to collect billions of events and identify among them the very rare
events that could present a new state of matter or new particles," CERN
spokesman Guido Tonelli told BBC News. "This is not going to happen
tomorrow. It will require months and years of patient work."
Once 7 TeV (1 TeV equals a million million electronvolts) collisions have been
established, the plan is to run the machine continuously for a period of 18to 24
months, with a short technical stop at the end of 2010. CERN said this would
bring enough data across all the potential discovery areas, including basic
laws governing the interactions and forces among the elementary objects, the
deep structure of space and time, and especially regarding the intersection of
quantum mechanics and general relativity.
"We're all emotional, and all very happy. This is our first important
milestone, and it's taken us three attempts this morning, as you probably
noticed," CERN’s director for
accelerators and technology, Steve Myers, said during the live Webcast.
Over the 2009 part of the run, each of the LHC’s four major experiments—ALICE,
ATLAS, CMS and LHCb—recorded over 1 million
particle collisions. Collisions at 7 TeV mark the start of the physics program
of the LHC; at those energies scientists will be able to cross-check data and
predictions from previous experiments and potentially discover predicted or
unpredicted particles that will help scientists understand how the universe
works.