Accelerator wakes from shutdown slumber

Many laboratory departments, led by the Accelerator Division, contributed to improvements in the Main Injector during the 13-week accelerator shutdown, which ended on Oct. 5. Photo: Reidar Hahn

Many laboratory departments, led by the Accelerator Division, contributed to improvements in the Main Injector during the 13-week accelerator shutdown, which ended on Oct. 5. Photo: Reidar Hahn

Cons Gattuso, Accelerator Division shutdown manager, keeps a digital spreadsheet of everything that needed to be done during the accelerator complex’s 13-week shutdown, which ended on Oct. 5. In total, it’s about 2,700 items, including both upgrades and routine maintenance. It’s a to-do list of monstrous proportions.

Upgrades to support muon experiments were the main driving force of the shutdown, primarily the installation of a new line that will deliver an 8-gigaelectronvolt proton beam to the Muon Campus. Installing this beamline was one of the hardest items to cross off the list. Crews had to thread the new beamline through a congestion of pre-existing beamlines. By disassembling and reassembling existing beamline, they managed to sneak it in — but just barely.

“In some locations, we had less than a tenth of an inch of space between components when we were done,” Gattuso said. During the shutdown crews also removed old, unused Tevatron parts, built two office-sized anode power supplies for the Booster’s beam-accelerating radiofrequency system and replaced the NuMI beam’s magnetic focusing horn.

Crews removed the old horn with a remote-controlled crane and put it in a special holding cell. Because old horns are too radioactive to fix, a brand new horn replaced the old one, ensuring that the accelerator complex will continue to deliver a quality neutrino beam to the laboratory’s neutrino experiments.

Crews pulled almost half a million feet of new cable, shuffled close to 2,500 tons of magnets and blocks, and modified nearly three-quarters of a mile of vacuum systems during shutdown. To execute work of such enormous size in the allotted timeframe, the Accelerator Division received labwide assistance.

“Without having that help from across the laboratory, there’s no way we would have been able to do this,” Gattuso said. “For some 13 weeks we came together as one laboratory in our tunnels working hand in hand to make this shutdown the success that it is. Kudos goes out to everyone.”

Merely swapping out one magnet requires the involvement of between 40 and 50 people from various departments and groups. Gattuso estimates that a couple hundred people moved in and out of the accelerator’s tunnels during its slumber. Many of those who didn’t actually journey into the tunnels labored elsewhere on to-dos or shared their equipment. Ultimately, this unity and collaboration allowed the accelerator to be up and running on time.

“On behalf of the entire Accelerator Division, I would like to thank our Fermilab colleagues for helping us accomplish our shutdown plan,” said Sergei Nagaitsev, head of the Accelerator Division.

With the accelerator complex’s hibernation over, things are less hectic for Gattuso, who joked that he might go golfing. His sigh of relief will be short-lived, however.

“Now we will start preparing for the next shutdown,” Nagaitsev said.