GENEVA (AFP) - Researchers announced Monday a new delay for the restart of Europe's Big Bang atom-smasher, saying the faulty multi-billion dollar machine would now be turned back on in late September. The European Organisation for Nuclear Research (CERN) had planned to relaunch the Large Hadron Collider (LHC) this spring before delaying it to the summer. But CERN management decided to aim for a September restart to reinforce protection systems. "The schedule we have now is without a doubt the best for the LHC and for the physicists waiting for data," CERN Director General Rolf-Dieter Heuer said in a statement. "It is cautious, ensuring that all the necessary work is done on the LHC before we start-up, yet it allows physics research to begin this year." The machine broke down only days after being switched on in September 2008, causing more than 30 million Swiss francs of repairs (20 million euros, 26 million dollars). CERN's new German director signalled in an interview late January that he would be more cautious than his French predecessor, with the relaunch having been repeatedly put back since the vast scientific experiment was launched amid worldwide fanfare last year. Heuer said then that the bill for repairs on the six billion Swiss franc particle accelerator could even reach 40 million Swiss francs. With 10,000 staff involved and after more than a decade of painstaking work, the first proton beams were fired down the new accelerator in a blaze of publicity on September 10, 2008, only to break down due to a helium leak from its cooling system nine days later. Heuer has said that he does not want to push for a full energy beam until 2010 at the earliest, after new protection systems have been added. "The new schedule foresees first beams in the LHC at the end of September this year, with collisions following in late October," CERN said in Monday's statement. The LHC " which runs through a 27-kilometre tunnel under the Franco-Swiss border near Geneva " is the most powerful in a series of atom-smashers at the 20-nation research organisation that have successfully helped advance knowledge of particle physics and the workings of the laws of nature since CERN was founded in 1954. Designed to shed light on the origins of the universe, the LHC took nearly 20 years to complete and cost six billion Swiss francs (3.9 billion euros, 4.9 billion dollars) to build in a tunnel complex under the Franco-Swiss border. It aims to resolve some of the greatest questions surrounding fundamental matter, such as how particles acquire mass and how they were forged some 13.7 billion years ago. In the countdown to the September launch, some scientists sought to halt the proceedings, convinced that the experiment could create black holes and extinguish life on Earth forever. Their apocalyptic fears turned out to be misplaced.