At the 131st session of Council on 17 December, CERN’s director-general Robert Aymar confirmed that the organization’s top priority is to maintain the goal of starting up the Large Hadron Collider (LHC) in 2007.
Preparations for the LHC project are advancing well, with half of the most technologically challenging components – the cold masses for the dipole magnets that will steer high-energy protons around the LHC’s 27 km ring – having arrived at CERN. In October the new transfer line that delivers protons from the Super Proton Synchrotron (SPS) to the LHC tunnel worked on the first attempt. The line is based on 540 magnets supplied by the Budker Institute for Nuclear Physics in Novosibirsk, and has been set up with the help of a team from the institute.
The discovery in 2004 of defects in newly installed components in the system that will distribute cryogenic cooling fluids around the ring meant that installation, which began in 2003, had to be put on hold. However, technical corrections have since been made, and in October the manufacture of new unflawed components began (see box). Repair of the faulty components started in November at CERN and the first modified items have been successfully installed in the LHC tunnel.
Various options to make up the delay have been discussed, and a strategy has been established to limit the impact on the overall schedule for the LHC. One option considered was to shut down the SPS in 2006 in order to divert human resources to LHC installation. However, this will not be necessary as long as technicians can be seconded for a few months from other accelerator laboratories.
A status report presented to Council on the four large experiments for the LHC – ATLAS, CMS, LHCb and ALICE – recognized the great progress that is being made. The schedule to get ready for collisions in the LHC in 2007 will be tight, but there is confidence that with some effort the experiments will start on time.
The SPS programme reached a natural pause at the end of the 2004 run, with most of its approved experiments reaching their conclusion; the SPS will not run in 2005. “This allows the community to take stock of where they are,” said Aymar, “and to plan for an exciting and well-focused programme for future fixed-target physics at CERN.” This procedure began in September in the Swiss village of Villars, where the SPS Committee met to set priorities for 2006 and beyond. As a result, Council will be examining proposals for new experiments during the course of 2005.