ATLAS e-News

ATLAS throws open its doors to the public

14 April 2008

Visitors posing for their souvenir photograph

Last weekend saw a record number of visitors to CERN, with a total of 76,000 people over two days, 31,000 of whom went underground to view one or more of the experiments and the tunnel. ATLAS e-News reporters were on the ground throughout the weekend, speaking with organisers and volunteers to get the latest on how the event was going.

As expected, ATLAS was one of the most popular sites, with queues to visit the detector itself snaking round past the Globe and out onto the street within half an hour of opening on each day. A total of 5,700 individuals were able to go underground; 2,200 friends and family of CERN staff on Saturday, and 3,500 members of the public on Sunday.

Caught on his lunch break on Sunday, site-1 manager Francois Butin said that the team were working at peak capacity, constrained only by the number of people the lift could carry. “We’re working hard to try to maximise the number of people that we’re taking underground. The lift is travelling continuously, so this is really the limiting factor. We started taking 20 per group yesterday; we’ve now increased to 25, but this is our absolute maximum capacity,” he explained. “If they aren’t already acquainted, people end up getting acquainted very quickly when there are 25 people in the lift!”

Describing the weekend so far as having been “tiring”, but looking cheerful and perky all the same, he added: “The nice thing is that many people have had a chance to take a ticket – we’ve handed out 200 for each one-hour slot – which means that they can go away and see something else, and then come back when their tour is starting.”

Planning how to get such huge numbers of people up and down the lift shaft was the logistical nightmare assigned to Helfried Burckhart. “We had to arrange the whole circuit around the lift capacity,” he explained. “I calculated all this, but of course there are always uncertainties. You never know how fast the lift will be filled and emptied, but it has turned out to be perfect. If you go from station to station, there’s no queue; there’s no bottleneck. So the chain is working well. A lot of planning went into the weekend, of course, but we’ve also had a lot of luck in that sense.”

Being limited to 300 people (ticketed and non-ticketed) per hour going underground inevitably meant that queues of people wanting to get a glimpse of the detector soon built up. The fact that people were prepared to wait in line for hours on end is a testament to just how keen they were to go underground, but there was evidence of frayed tempers on more than one occasion.

“Some people were really getting desperate after waiting in queue for four and even five hours, especially on Sunday when it was so cold,” explained volunteer guide Pauline Gagnon. “One woman told me she was near hypothermia, but the CERN staff assigned to security refused to let her group wait in the empty tent, sheltered from the wind. I was so outraged that I let them into the tent myself. I really felt it was an honour to get so much public interest; the least we could do was to bend over backward to do it right.”

Pauline was full of praise for the ATLAS volunteers, however, who made the best of the situation: “On the ATLAS side of that entrance fence, I think it was a great success. We were really efficient and well organised.” Thinking on the spot, Connie Potter sent people out to help entertain the crowds during their long wait. ATLAS Resources Coordinator, Markus Nordberg, and Kerstin Jon-And, Chair of the Collaboration Board, stepped in – going up and down the queue with other volunteers; handing out stickers, balloons, sweets, and leaflets; and discussed physics with people while they waited.

When they did reach the front of the queue, all thoughts of the wait seemed to dissolve, as visitors were first treated to a whistle-stop ten-minute explanation of ATLAS and the LHC in the control room, where they were also able to see real physicists at work. Next, they moved upstairs to view a hugely popular 3D movie showing the construction of the detector, which whet their appetite nicely, in time for the real thing. Finally, they were taken down into the pit in groups to view the detector itself.

Following the tour, those that wanted to could carry on to the huge ATLAS tent, where they could ask questions about ATLAS and browse the various stalls. “We had the advantage of having the staff day on the Saturday, so it was kind of like a dry run, and we found some things we could improve upon for the Sunday,” said Connie Potter, who was responsible for coordinating the activities in the tent. “I was really pleased with the way all the stands went, and the fact that the tent became a real place of interaction between the public and the guides.”

Mechanical technicians Neil Dixon and Francisco Perez Gomez were busy showing people parts of the inner detector, on their stand in the tent. “We’re showing people what we’ve been working on for the last sixteen years,” said Neil. “All the bits we’ve brought are the things we want people to touch; we want them to feel the detector, play with the parts, ask questions.” There was even a wiring station, where visitors were challenged to thread a delicate wire, thinner than a human hair, through a tiny crimp tube – a step completed 80 times per hour by ATLAS technicians when they were assembling the 300,000 straws present in the inner detector, each with two crimp tubes on their ends. “It really illustrates to people how much skill has been involved in building this detector,” Neil said. “Very few people coming to the stand today have been able to do it.”

Of course, friends, family, and the public weren’t the only visitors to the detector over the weekend. Peter Higgs himself was guest of honour in the cavern, and journalists from all over the world came to take a look too. James Randerson from the science desk of UK national newspaper The Guardian described the LHC tour as “one of the most astonishing and mind-blowing sights of [his] journalistic career”.

“The idea that we will be creating conditions not seen since a fraction of a second after the big bang just blows my mind,” he added. “No wonder over 70,000 people came. From what I saw, organisation was as good as it could be in the circumstances, but inevitably, thousands were going to be leaving disappointed because the lifts underground simply couldn’t move fast enough.”

The whole tour lasted around forty minutes, and judging by the reactions of the lucky 5,700 who got the once-in-a-lifetime chance to see the ATLAS detector up close, it was well worth the wait.

Ceri Pe kins ATLAS eNews