CERN Accelerating science

This website is no longer maintained. Its content may be obsolete. Please visit for current CERN information.

LHC Milestones

LHC Milestones

back button scroller forward button inactive
year 2008



The last of the 15 slices of CMS is lowered into the experiment cavern putting an end to 15 months of spectacular 100 metre descents underground.

The last of the fifteen slices of CMS is lowered into the experiment cavern



The last element to be installed in the ATLAS detector takes the plunge into its cavern. With a diameter of 9.3 metres and weighing 100 tonnes, this small wheel completes the muon detector of the experiment.
Lowering of one of the two ATLAS muon small wheels into the cavern


The last crystals for CMS’s electromagnetic calorimeter arrive from Russia and China, nearly 10 years after the first production crystal was sent to CERN in September 1998. These crystals will be used to complete the end-caps of the electromagnetic calorimeter at CMS.
CMS crystals being mounted onto one section of the ECAL end-caps



CMS and ATLAS close the LHC ring by installing beampipes at the heart of their experiments.
Installation of the CMS beam pipe.


The Open days on the 5th and 6th April attract 76,000 visitors to CERN. It is the one and only opportunity for the public to visit the tunnel to discover the LHC and the four big experiments before the accelerator is switched on.

Open Day 2008



CERN's aerial view and the LHC tunnel

The adventure begins soon.

Scheduled to start in 2008, the LHC is making the final preparations before embarking on a new era of discovery at the high energy frontier.

LHC experiments will address questions such as what gives matter its mass, what the invisible 96% of the Universe is made of, why nature prefers matter to antimatter and how matter evolved from the first instants of the Universe’s existence.



The beampipes, the place where collisions are produced, are now operational.  A vacuum, such as exists in the moon’s atmosphere, reigns in the 54 kilometres of beampipe.






The 27 kilometres of the LHC have attained the –271°C needed for the experiment. This is just two degrees from absolute zero, the lowest temperature imaginable. The operation needed more than 10,000 tonnes of liquid nitrogen for the first step of the cool down, and 150 tonnes of helium to completely fill the magnets.

LHC cooldown status




Particles have circulated in the LHC for the first time.  Two bunches of particles were accelerated by CERN’s accelerator chain and then sent in opposite directions around the LHC.  The profile of one of these two beams is shown in this image.
LHC injection test results

year 2005 year 2005-1 year 2005-2 year 2005-3 year 2004-5 year 2004-4 year 2004-3 year 2004-2 year 2004-1 year 2003-6 year 2003-5 year 2003-4 year 2003-3 year 2003-2 year 2003-1 year 2003 year 2002-3 year 2002-2 year 2002-1 year 2002 year 2001-4 year 2001-3 year 2001-2 year 2001-1 year 2001 year 2000-2 year 2000-1 year 2000 year 1999-2 year 1999-1 year 1999 year 1998-2 year 1998-1 year 1998 year 1997 year 2005-9 year 2005-8 year 2005-7 year 2005-6 year 2005-5 year 2005-4 year 1996 year 1995 year 1994 year 1997-1 year 2006-7 year 2006-6 year 2006-5 year 2006-4 year 2006-3 year 2006-2 year 2006-1 year 2006 year 2007 year 2007-1 year 2007-2 year 2007-3 year 2007-4 year 2007-5 year 2008