Half a day into the hotly anticipated “start up” day of the Large Hadron Collider (LHC), the operations team has scored a home run going clockwise and is now trying to circulate a proton beam in the anticlockwise direction.

Inside the state-of-the-art control room at CERN, the European lab hosting the accelerator, some 50 to 100 senior members of the project have had their eyes fixed on an array of plasma-screen monitors as bunches of protons made their way step-by-step through the 27 km-long ring. The first proton beam fired into the ring at 9:30 am CET (8:30 am BST) and in just under an hour a beam had made it all the way round.

I think we are quite excited and quite happy Robert Aymar, director general of CERN

For the throng of journalists packed into the science and innovation “globe”, the 10,000 or so other CERN staff and users, and the many thousands of physicists worldwide all on the edge of their seats, that time seemed almost unbelievably short.

“I think we are quite excited and quite happy,” said Robert Aymar, director general of CERN. He then thanked all those who participated, particularly Lyn Evans, the project leader.

Just as the champagne corks popped, Evans was overheard saying he had “won the bet”. He later admitted that the bet was with Steve Myers, the head of the accelerators department, that they would get a beam round in less than an hour. “[Myers] refused to put the money up,” he added, though did not specify the amount.

‘Exceeded expectations’

Although the feeling among many at CERN yesterday was that today is an arbitrary date for a “switch on” — the LHC first received protons on 8 August — there is no understating the excitement that is now flooding through the European lab.

The priority is to get both beams circulating…then I think everyone will be so tired we won’t get anything else done Verena Karin, LHC operators

Roger Jones is a physicist from Lancaster University in the UK who is working on the ATLAS experiment, which was the last to see its detectors light up as the proton beam passed through today. “I predicted the beam would get round by 11:00 am,” he said, “so it exceeded my expectations.” Because Jones was working in the upstairs control room at ATLAS where there is no video link, he kept up to date with events by listening to the radio.

The operations team now expects that the €6.3 bn particle accelerator, which is by far the world’s most powerful, will have managed to circulate a proton beam in both directions by the end of day.

“The priority is to get both beams circulating…then I think everyone will be so tired we won’t get anything else done,” said Verena Karin, one of the LHC operators, during a long-distance interview from the control room. When asked whether the feeling in the control room was similar to that felt in NASA mission control during a Mars landing, she said: “I have not been there, but yes, I imagine it was exactly like that.”

physicsworld.com asked Karin what her message would be to all the other researchers who are eagerly watching the events unfold. “Keep watching,” she answered. “It’s really really good, it’s really really exciting. It’s like the Olympics.”