The Large Hadron Collider (LHC), the world’s largest scientific experiment, came to an abrupt halt on the 19th of September, just nine days after it was switched on.
The failure caused the LHC to leak over a tonne of liquid helium resulting in 100 of the system’s 9500 magnets to overheat. While the machine usually operates at -271C, a few degrees above absolute zero, the temperature of the magnets in sections three and four of the ring rose by 100 degrees. At the time of the malfunction the LHC was operating at just 10% of its full potential.
The exact nature of the fault is under investigation but experts already estimate that it will take a month to warm the machine up to a temperature at which it can be repaired. The cooling process will take a further month and the project will also be put on hold over the winter. This means that the LHC will not be back online until spring 2009.
Robert Aymar, CERN Director General, told press that in spite of the impact of this early setback, the machine’s teething problems were in no way insurmountable.
He said: “Coming immediately after the very successful start of LHC operation on September 10, this is undoubtedly a psychological blow.
Nevertheless, the success of the LHC’s first operation 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 the same degree of rigour and application.”
This is not the first setback for the LHC: in 2005 a technician died in a construction accident on-site. The project is also two years behind schedule after CERN’s budget was reduced in 2001. It is estimated that the whole project could cost as much as €6.4 billion. This most recent malfunction comes immediately after a week of delays due to the replacement of a faulty tramsformer.
The LHC was built to simulate the moments just after the Big Bang by firing beams of protons around a 27 km underground tube below Geneva at a speed of 11,245 revolutions a second or 99.99% the speed of light.
Before the magnets overheated scientists were able to observe the first particles being accelerated in the LHC. Dr. Chris Parkes, professor of Physics and Astronomy at University of Glasgow, is the British Vertex Locator (VELO) Project Leader and VELO software co-ordinator.
He said: “The particles were seen by the team of scientists within seconds, and from the very first collision.”
Dr Eduardo Rodrigues, a research assistant in the Glasgow LHC group and VELO data quality co-ordinator described the moment at which the first results were recorded.
He said: “I had worked on the real-time monitoring plots which allowed us to see the particles traversing the detector. I was overwhelmed when we saw the evidence of the particle tracks clearly appearing on the computer monitors in the control room”.
