Category Archives: LHC

CERN sets date for first attempt at 7 TeV collisions in the LHC

Geneva, 23 March 2010. With beams routinely circulating in the Large Hadron Collider at 3.5 TeV, the highest energy yet achieved in a particle accelerator, CERN has set the date for the start of the LHC research programme. The first attempt for collisions at 7 TeV (3.5 TeV per beam) is scheduled for 30 March.

0911182_43-A4-at-144-dpi “With two beams at 3.5 TeV, we’re on the verge of launching the LHC physics programme,” explained CERN’s Director for Accelerators and Technology, Steve Myers. “But we’ve still got a lot of work to do before collisions. Just lining the beams up is a challenge in itself: it’s a bit like firing needles across the Atlantic and getting them to collide half way.”

Between now and 30 March, the LHC team will be working with 3.5 TeV beams to commission the beam control systems and the systems that protect the particle detectors from stray particles. All these systems must be fully commissioned before collisions can begin.

“The LHC is not a turnkey machine,” said CERN Director General Rolf Heuer.“The machine is working well, but we’re still very much in a commissioning phase and we have to recognize that the first attempt to collide is precisely that. It may take hours or even days to get collisions.”

The last time CERN switched on a major new research machine, the Large Electron Positron collider, LEP, in 1989 it took three days from the first attempt to collide to the first recorded collisions.

The current LHC run began on 20 November 2009, with the first circulating beam at 0.45 TeV. Milestones were quick to follow, with twin circulating beams established by 23 November and a world record beam energy of 1.18 TeV being set on 30 November. By the time the LHC switched off for 2009 on 16 December, another record had been set with collisions recorded at 2.36 TeV and significant quantities of data recorded. Over the 2009 part of the run, each of the LHC’s four major experiments, ALICE, ATLAS, CMS and LHCb recorded over a million particle collisions, which were distributed smoothly for analysis around the world on the LHC computing grid. The first physics papers were soon to follow. After a short technical stop, beams were again circulating on 28 February 2010, and the first acceleration to 3.5 TeV was on 19 March.

Once 7 TeV collisions have been established, the plan is to run continuously for a period of 18-24 months, with a short technical stop at the end of 2010. This will bring enough data across all the potential discovery areas to firmly establish the LHC as the world’s foremost facility for high-energy particle physics.

A webcast will be available on the day of the first attempt to collide protons at 7TeV. More details will be available at:


CERN Press Office,
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1.CERN, the European Organization for Nuclear Research, is the world’s leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.

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Posted by on March 30, 2010 in LHC, Physics, Science News



Large Hadron Collider Triples Its Own Record – 3.5 TeV

CERN Operations Group leader Mike Lamont (foreground) and LHC engineer in charge Alick Macpherson in the CERN Control Centre early this morning.

In the early hours of this morning, the beam energy was ramped up to 3.5 TeV, a new world record and the highest energy for this year’s run. Now operators will prepare the machine to make high-energy collisions later this month.

At 5:23 this morning, Friday 19 March, the energy of both beams in the LHC was ramped up to 3.5 TeV, a new world record. During the night, operators had tested the performance of the whole machine with two so-called ‘dry runs’, that is, without beams. Given the good overall response, beams were injected at around 3:00 a.m. and stabilized soon after. The ramp started at around 4:10 and lasted about one hour.

In my message this week, I’d like to congratulate the LHC team on accelerating two beams to 3.5 TeV in the early hours of this morning. The timing could not have been better. Coming during a week of CERN Council meetings, it allowed us to show delegates the great progress we’re making.

The occasion also gave us the opportunity to set out again the prudent step-by-step approach that we’re taking to get the LHC up and running, and it was refreshing to hear one member of the Scientific Policy Committee declare on Monday that we should never forget that the LHC is not a turnkey machine.With the progress the LHC is making, that simple fact would be easy to overlook. The figures coming back from this first run are already quite remarkable. In Week 10, the LHC’s availability for the operators was over 65%: it usually takes a new accelerator years to reach that level. And over the last few weeks, operation of the LHC at 450 GeV has become routinely reproducible, which is again a feat that usually takes a new machine much longer to achieve.

Over the last couple of weeks, operation of the LHC at 450 GeV has become routinely reproducible. The operators were able to test and optimize the beam orbit, the beam collimation, the injection and extraction phases as well as the associated protection system. On 12 March, both beams were ramped up to 1.18 TeV. The overall response from the machine was very positive.

The first part of this week saw a technical stop, during which the magnet and magnet protection experts continued their campaign to commission the machine to 6 kAmps – the current needed to operate at 3.5 TeV per beam. Tests are still ongoing to fully understand the electrical behaviour of the dipole circuits with currents higher than 2 kAmps, which has an impact on the quench protection system (see box) and on the procedure for ramping the beam energy to 3.5 TeV (6kAmps).

While the experts are working to fully understand the circuit performance (for details, watch the embedded video interview with Andrzej Siemko, Group Leader of the LHC machine protection), the operators will continue ramping the beam energy and prepare for high-energy collisions later this month.

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Posted by on March 21, 2010 in LHC, Physics, Science News


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