Latest LHC News

15 May, 2009

On May 15, 2009, Sony Pictures Entertainment released Angels & Demons, starring Tom Hanks. The film focuses on an apparent plot to destroy the Vatican using antimatter stolen from the European particle physics laboratory CERN.

Through a series of public lectures, scientists are using this opportunity to tell the world about the real science of antimatter, the Large Hadron Collider and the excitement of particle physics research. CERN has invited Tom Hanks to return late in 2009 and throw the switch to restart the LHC.

Public Lectures

Angels & Demons - The Science Revealed

Geneva, 30 April 2009

The 53rd and final replacement magnet for CERN’s Large Hadron Collider (LHC) was lowered into the accelerator’s tunnel today, marking the end of repair work above ground following the incident in September last year that brought LHC operations to a halt. Underground, the magnets are being interconnected, and new systems installed to prevent similar incidents happening again. The LHC is scheduled to restart in the autumn, and to run continuously until sufficient data have been accumulated for the LHC experiments to announce their first results.

The final magnet, a quadrupole designed to focus the beam, was lowered this afternoon and has started its journey to Sector 3-4, scene of the September incident. With all the magnets now underground, work in the tunnel will focus on connecting the magnets together and installing new safety systems, while on the surface, teams will shift their attention to replenishing the LHC's supply of spare magnets.

In total 53 magnets were removed from Sector 3-4. Sixteen that sustained minimal damage were refurbished and put back into the tunnel. The remaining 37 were replaced by spares and will themselves be refurbished to provide spares for the future.

CERN is publishing regular updates on the LHC in its internal Bulletin, available at http://www.cern.ch/bulletin , as well as via twitter and

YouTube at http://www.twitter.com/cern  and http://www.youtube.com/cern

 

Geneva, 5 December 2008

LHC to restart in 2009
CERN has conducted a detailed analysis of the problem that occurred and has now issued a new schedule for LHC operation. It is expected that beams will be circulated and collisions occur in late summer 2009. You can read the press release and see some images of the damage at http://press.web.cern.ch/press/PressReleases/Releases2008/PR17.08E.html

 

Geneva, 16 October 2008.

Analysis of the Large Hadron Collider Incident

On the 19th of September an electrical connection failed as current was being increased in the magnets that guide the proton beams. There is now a detailed analysis of the cause of the failure

http://press.web.cern.ch/press/PressReleases/Releases2008/PR14.08E.html

As yet there is no definite time table for the LHC to circulate beam but the earliest date would be May 2009.
 

Geneva, Tuesday September 23rd, 2008

 Investigations at CERN following a large helium leak into sector 3-4 of the Large Hadron Collider (LHC) tunnel have indicated that the most likely cause of the incident was a faulty electrical connection between two of the accelerator’s magnets. Before a full understanding of the incident can be established the sector has to be brought to room temperature and the magnets involved opened up for inspection.  This will take three to four weeks. Full details of this investigation will be made available once it is complete.

"Coming immediately after the very successful start of LHC operation on 10 September, this is undoubtedly a psychological blow," said CERN Director General Robert Aymar.
"Nevertheless, the success of the LHC’s first operation with beam is testimony to years of painstaking preparation and the skill of the teams involved in building and running CERN’s accelerator complex. I have no doubt that we will overcome this setback with same degree of rigor and application."

The time necessary for the investigation and repairs precludes a restart before CERN’s
obligatory winter maintenance period, bringing the date for restart of the accelerator complex to early spring 2009. LHC beams will then follow.
Particle accelerators such as the LHC are unique machines, built at the cutting edge of technology. Each is its own prototype, and teething troubles at the start-up phase are always possible.

Explanation
Handling and storing liquid Helium and the complicated procedures necessary for warm up and cool down set the time for warm up to a few weeks and a total time of two months providing any repair is straightforward.  The total complex at CERN involves many accelerators and a number of other experiments and a shutdown from early December until March was always part of the schedule and cannot be changed.

Monday September 22nd, 2008 

At the following link you can find a special issue of the CMS time which is a special edition to commemorate the first circulation of beam in the LHC and its first trip through the CMS detector.
                              http://cmsinfo.cern.ch/outreach/CMSTimes.html

Friday September 19th ,2008

During commissioning (without beam) of the final LHC sector (sector 34) at high current for operation at 5 TeV, an incident occurred at mid-day on Friday 19 September resulting in a large helium leak into the tunnel. Preliminary investigations indicate that the most likely cause of the problem was a faulty electrical connection between two magnets which probably melted at high current leading to mechanical failure. CERN's strict safety regulations ensured that at no time was there any risk to people. A full investigation is underway, but it is already clear that the sector will have to be warmed up for repairs to take place. This implies a minimum of two months down time for the LHC operation. For the same fault, not uncommon in a normally conducting machine, the repair time would be a matter of days.

Explanation
The magnets in the LHC produce a force on the circulating protons which provides the centripetal force to keep the protons moving in a circular path of radius ~ 2.7 miles. Protons are injected into the LHC at low energy and then accelerated. As the energy (and speed) increases the magnet field has to increase to keep the protons at a fixed radius and therefore the current in the coils of the magnets has to be increased.  During the test of high current operation a component failed. As in the case of any normal conductor heat is produced as a current flows (e.g. a toaster) in the failure this heat caused a connection to melt.