Following the successful circulation of first beam in the LHC on 10th September, the world’s largest and most complex scientific instrument will be officially inaugurated at CERN on 21st October 2008, the organisation has announced.

Representatives of the governments of CERN’s Member and Observer States and other participating nations have been invited.

The LHC’s start-up day went very smoothly, with the first beam being threaded around the ring to great acclaim in just under one hour.

After ten days of operation however, the LHC is now on stand-by. A fault in one of its eight sectors which resulted in a helium leak is under investigation, which requires warming up the sector from -271 Celsius to room temperature.

This will take several weeks, after which the repair can be made and the sector cooled down. The warm-up and investigation phases will span through until November, when the CERN’s entire research infrastructure, including all particle accelerators and experiments, is shut down for annual maintenance until spring 2009.

It’s already been announced that the LHC operations are scheduled to restart in spring 2009, but before then the particle accelerator instrument is set to be inaugurated on 21st October.

“CERN personnel and colleagues from around the world have reacted to the current situation with their customary professionalism and determination,” said CERN Director General Robert Aymar.

“While the timing is undoubtedly a disappointment, a few extra weeks on a project that has been over two decades in the making is not very much. It is simply a fact of life in experimental physics at the frontiers of knowledge and technology.”